README.md rewritten sentence by sentence (closes #219)

The old text served as the list of what a reader needs covered. The new
text leads with what quak is, what it is for and how to use it. Every
command, option, exit code and file layout follows in reference sections,
then the library reference, then design, entrypoints and development.
Every statement was checked against the code on next; where the old text
disagreed, the pull request lists it. No sentence runs past about 30
words, every table is now a list, and no issue links or project history
remain in text meant for users. Two code comments that named README
sections now name the new ones; a third no longer cites the README.

Model: fable-5-1

TODO.md

@@ -17,15 +17,161 @@ pre-1.0
 
 # Next Step
 
-None: no implementation work is open. The check of quak against a live Ente
+No bug is open, and no change sneak asked for is open. The check of quak against
-account, https://git.eeqj.de/sneak/quak/issues/187, needs an account only sneak
+a live Ente account, https://git.eeqj.de/sneak/quak/issues/187, needs an account
-has, so it waits on him.
+only sneak has, so it waits on him.
 
 Tagging and releases are decided by sneak alone, and happen only when he
 declares one.
 
 # Completed Steps
 
+- 2026-10-26: On an empty cache, `quak helper fix-missing-thumbnails --file`
+  stops fetching collections' files once it finds every file it names
+  (https://git.eeqj.de/sneak/quak/issues/223). It used to wait for a refresh,
+  which on an empty cache fetched the files of every collection. Now it reads
+  the collection list, then one collection's files at a time, the most recently
+  updated first. It stores none of the collections or file records it reads. It
+  fetches each original through `lib.originalOf()`, which keeps it in the cache.
+  Once the cache holds the account's collections, it still waits for a refresh.
+
+- 2026-10-26: On an empty cache, `quak get` and `quak get-thumb` stop fetching
+  collections' files once they find the file
+  (https://git.eeqj.de/sneak/quak/issues/222). They used to wait for a refresh,
+  which on an empty cache fetched the files of every collection. Now they read
+  the collection list, then one collection's files at a time. They store none of
+  the collections or file records they read, and fetch the original or thumbnail
+  through the new `lib.originalOf()` and `lib.thumbnailOf()`. Once the cache
+  holds the account's collections, they still wait for a refresh.
+
+- 2026-10-26: `quak files` with a collection ID fetches that collection's files
+  alone (https://git.eeqj.de/sneak/quak/issues/217). It used to wait for a
+  refresh, which on an empty cache fetched the files of every collection. It now
+  reads the collection list through `lib.freshCollections()`, then the one
+  collection's files through the new `lib.freshFiles()`. It stores nothing, and
+  the files print in the server's order.
+
+- 2026-10-22: The JSON `quak backup` and `quak backup-metadata` write for a file
+  holds `keywords` in place of the CLIP embedding in its ML data
+  (https://git.eeqj.de/sneak/quak/issues/218). The keywords are the titles of
+  the Discover categories of Ente's photos app that the file falls in, by the
+  app's rule: the cosine similarity of the file's CLIP embedding and the text
+  embedding of a category's query is at least the category's minimum score, and
+  videos stay out of the categories that leave them out. `src/clip-keywords.ts`
+  applies the rule. `src/clip-keyword-vectors.ts` holds the 16 categories with
+  their text embeddings. `bin/clip-keyword-vectors` writes it with Ente's CLIP
+  text model, and writes the CLIP embedding of a public-domain photo of a sunset
+  that the tests use.
+
+- 2026-10-18: `-v`/`--verbose` raises the CLI's log level once for each repeat,
+  and `-q`/`--quiet` prints only fatal errors
+  (https://git.eeqj.de/sneak/quak/issues/212). The levels are fatal, error,
+  warning, info, debug and trace; the default is info, everything quak printed
+  on stderr before, `-v` gives debug and `-vv` trace. `src/cli-log.ts` holds the
+  level and the log the commands write stderr lines through. Debug adds each
+  retry, which `withRetry` reports through the new `onRetry`, and the start and
+  end of each refresh and ML data fetch; trace adds each request, which
+  `ApiClient` reports through the new `onRequest`. `--json` no longer keeps the
+  progress lines off stderr, so `backup` and `--json` runs log a refresh's
+  progress too. Every line that reports a failed file or album is at error,
+  which the progress callbacks of `backup`, `backup-metadata` and the thumbnail
+  helpers now say, and a command that exits 1 because files or albums failed
+  ends with one fatal line saying how many and where to look.
+
+- 2026-10-18: `quak files` takes the collection ID as an optional argument
+  instead of the `--collection` option, which is gone
+  (https://git.eeqj.de/sneak/quak/issues/211). With no argument it lists every
+  file in the account once, collection by collection; a file in several
+  collections is listed with the first of them, which is its `collectionID` in
+  `--json`. The fresh read in `src/cli-read.ts` does this.
+
+- 2026-10-18: Names quak builds from an album name or a title fit in a file name
+  (https://git.eeqj.de/sneak/quak/issues/205). `shortenKeepingExtension` in
+  `src/filename.ts` cuts a name short to a number of bytes, keeping its
+  extension when it fits and always its first character, and can put text right
+  before the extension; the backup's `withID` uses it for an ID.
+  `defaultFileName` there gives the name a file is saved under when the caller
+  gives no path: a prefix such as `thumb_` and the title with unsafe characters
+  replaced, cut short with it to 255 bytes, and, for a live photo's image or
+  video, with that part's own extension before the cut. `quak get`,
+  `quak get-thumb`, `downloadFile` and `downloadThumbnail` use it without
+  `--out` or `outPath`. `backup-metadata` cuts an album's name short so that its
+  folder, `<id>-<name>`, fits in 255 bytes. `safeExtension` gives `.bin` for an
+  extension of more than 16 letters and digits, so a save path's name always
+  fits.
+
+- 2026-10-18: `quak collections` no longer waits for the files of every
+  collection (issue 210). On an empty cache it opened its library with a refresh
+  that fetched and decrypted the files of each collection in turn, printing
+  nothing and storing nothing until all were done, so on a large account it
+  seemed to hang. It now reads the collection list alone through the new
+  `lib.freshCollections()`, one request that stores nothing. The read commands
+  open their library with the new `refreshOnOpen: false`, so each makes only the
+  refresh it asks for. A refresh sends a `"progress"` event after each
+  collection whose files it fetched, and the commands that wait on one print it
+  on stderr, except with `--json`.
+
+- 2026-10-16: ML data the server sends that does not decrypt, gunzip or parse is
+  no longer taken for no ML data (issue 198). `fetchMLDataBatch` returns why for
+  each such file beside the payloads; ML data that parses to something other
+  than a JSON object, such as `null`, is one of them. The library keeps the
+  reasons from its last ML data fetch that succeeded in memory, not in the
+  cache, and gives them in `status().mlDataErrors` and in the `fetchMLData`
+  event with status `"done"`; a fetch still running or one that fails does not
+  change them. `quak backup` writes the reason as `mlDataError` in the file's
+  JSON when no ML data is cached for it, and records the file in `failures.json`
+  with an error starting `ML data: `; `backup-metadata` writes `mlDataError`
+  too. Both exit 1. Tests serve ML data encrypted under a key that is not the
+  file's.
+
+- 2026-10-16: With `--verify`, an original whose hash does not match is no
+  longer removed before its replacement is downloaded (issue 199).
+  `replaceOriginal` in `src/library/content.ts` downloads the replacement to a
+  temporary file beside it, a live photo's image and video each to its own,
+  hashes it and renames it over the original only when it matches. When the
+  download fails or does not match either, the original keeps its bytes and
+  links, and the file goes into `failures.json`. The replacement is always
+  downloaded, through the new `fetchOriginal` of the content cache, never copied
+  from the cache.
+
+- 2026-10-16: The `~/bin/quak` that `make install` builds retries a refused
+  connection and a name that does not resolve, and the backup records either as
+  transient (issue 206). Bun's `fetch` reports them with codes of its own,
+  `ConnectionRefused` and `FailedToOpenSocket`, which `src/retry.ts` now counts
+  as transport failures. A `POST` or `PUT` is not replayed on them, because bun
+  also gives them when it resends a request on a new connection after a
+  connection it kept open closed, and the server may already have the request.
+  Bun already gave `ECONNRESET` for a reset and a `TimeoutError` for a deadline.
+  `classify` in `src/backup.ts` now records any `TimeoutError` as transient, so
+  a stalled download, whose error says only that it stalled, is no longer
+  `unknown`. The shapes were found by running the binary against local
+  listeners.
+
+- 2026-10-15: An album whose folder or JSON `quak backup` cannot write no longer
+  ends the run before the other albums and `failures.json` are written (issue
+  197). The run prints `FAILED album <name>: <reason>`, lists the album's ID in
+  `failedAlbums` in the result and in `--json`, goes on, and exits 1. An album
+  whose folder would have the name of another album's JSON, as `x.json` beside
+  `x` would, gets its ID added. A folder or link name over 255 bytes is cut
+  short between two characters, by `shortenToBytes` in `src/filename.ts`, and
+  gets the ID.
+
+- 2026-10-15: A network failure is printed and recorded with its reason, not as
+  just `fetch failed` (issue 196). `describeError` in `src/errors.ts` gives an
+  error's message followed by the message of each error on its `cause` chain,
+  such as `fetch failed: connect ECONNREFUSED 1.2.3.4:443`, and each address's
+  reason when a host has several and none could be reached. `run` prints that,
+  and the backup logs it and records it in `failures.json`, where `classify` now
+  calls the failure transient when the chain holds an errno that
+  `hasTransportCode` in `src/retry.ts` recognises, for a failed ML data fetch
+  too. The walk along the chain moved from `src/retry.ts` to `src/errors.ts`,
+  which both use. Tests refuse every connection of a backup, then only one
+  file's download, and fail the ML data fetch.
+
+- 2026-10-15: The README says that `make install` needs nix (issue 200), in
+  Getting Started and in "Running the backup from cron": `make build-bin` runs
+  bun through `nix-shell -p bun`. The `Makefile` is unchanged.
+
 - 2026-10-14: `lib.backup()`, and so `quak backup`, works on up to the content
   pool's limit of originals at once, 5 by default, instead of one at a time
   (issue 182). That many workers take files from one shared list, each doing all

bin/clip-keyword-vectors

@@ -0,0 +1,31 @@
+#!/bin/sh
+# Writes src/clip-keyword-vectors.ts and test/clip-keywords-sunset.json by
+# running bin/clip-keyword-vectors.py in a Python image pinned by digest, with
+# its packages pinned by hash. Run it by hand from a checkout, then `make fmt`;
+# no gate runs it. Besides the Python image, it downloads about 265 MB, most of
+# it Ente's two CLIP models.
+set -eu
+
+ROOT="$(cd "$(dirname "$0")/.." && pwd -P)"
+
+# python:3.13-slim (Python 3.13.17 on Debian 13.7), 2026-10-21. The wheels
+# below are the ones for this image on linux/amd64.
+IMAGE=python@sha256:57b29a7c050c4e679e4bea572e14b3965cf4b5839de2da49d55e49ffc4024f39
+
+main() {
+    cd "$ROOT"
+    docker run --rm -i --platform linux/amd64 \
+        --user "$(id -u):$(id -g)" -e HOME=/tmp \
+        -v "$ROOT:/repo" -w /repo "$IMAGE" sh -c '
+            python -m venv /tmp/venv &&
+            /tmp/venv/bin/pip install --quiet --disable-pip-version-check \
+                --no-cache-dir --no-deps --require-hashes -r /dev/stdin &&
+            /tmp/venv/bin/python bin/clip-keyword-vectors.py' <<'EOF'
+numpy==2.5.3 --hash=sha256:a5fa86b80fd24bcd1aff83ad23be44ea323de3f787be8f8b15d4a65621e25321
+onnxruntime==1.30.0 --hash=sha256:86f940afc801ea9681a4da8af84fbe95e1d9ea7d80903952cc1bfad54faad38f
+pillow==12.3.0 --hash=sha256:0847a763afefb695bc912d7c131e7e0632d4edc1d8698f58ddabec8e46b8b6d3
+tokenizers==0.23.2 --hash=sha256:41c2f84d172449b4dadb9cdc508e3e364076613c35b16e76ecfe47a60d1e3305
+EOF
+}
+
+main "$@"

bin/clip-keyword-vectors.py

@@ -0,0 +1,158 @@
+"""Write src/clip-keyword-vectors.ts and test/clip-keywords-sunset.json.
+
+bin/clip-keyword-vectors runs this in a pinned Python image. It downloads
+Ente's Discover list, Ente's CLIP text and image models, the CLIP tokenizer
+and a public-domain photo of a sunset, checks each against its sha256, and
+writes:
+
+- src/clip-keyword-vectors.ts: each Discover category of Ente's photos app,
+  with the text embedding Ente's CLIP text model gives its query;
+- test/clip-keywords-sunset.json: the CLIP embedding Ente's image model gives
+  the photo, prepared as Ente's apps prepare a photo.
+
+Both embeddings are scaled to length 1, as Ente's apps scale them.
+"""
+
+import hashlib
+import io
+import json
+import urllib.request
+
+import numpy as np
+import onnxruntime
+from PIL import Image, ImageOps
+from tokenizers import Tokenizer
+
+ENTE_COMMIT = "f5ad70a860ed25d0c8057b0efb4bd6eaefe4b0c5"
+DISCOVER_PATH = "mobile/apps/photos/assets/discover.json"
+DISCOVER_URL = (
+    f"https://raw.githubusercontent.com/ente-io/ente/{ENTE_COMMIT}/{DISCOVER_PATH}"
+)
+DISCOVER_SHA256 = "cf70ac7116b592f7921ca4cf67cdbb421a8e6b287fbe44b2be678b8d198e5c24"
+
+TEXT_MODEL = "mobileclip_s2_text_opset18_quant.onnx"
+TEXT_MODEL_SHA256 = "d92f33dfcff83077fc2e0d3414250710efbb51795dfd89767bdbefb5fdc47322"
+IMAGE_MODEL = "mobileclip_s2_image_gelu_opset20.onnx"
+IMAGE_MODEL_SHA256 = "205a430af825e501c5138e5bb9abea942482a7a4fd4a680e98e47cf0830dce7e"
+
+# The CLIP tokenizer Hugging Face publishes for OpenAI's CLIP. Its vocabulary
+# and merges are those of bpe_simple_vocab_16e6.txt, the vocabulary Ente's
+# apps tokenize with.
+TOKENIZER_URL = (
+    "https://huggingface.co/openai/clip-vit-base-patch32/resolve/"
+    "3d74acf9a28c67741b2f4f2ea7635f0aaf6f0268/tokenizer.json"
+)
+TOKENIZER_SHA256 = "b556ac8c99757ffb677208af34bc8c6721572114111a6e0aaf5fa69ff0b8d842"
+
+# "Sunset off the Massachusetts coast", a NOAA photo in the public domain:
+# https://commons.wikimedia.org/wiki/File:Sunset_off_the_Massachusetts_coast_-_NOAA.jpg
+PHOTO_URL = (
+    "https://upload.wikimedia.org/wikipedia/commons/d/db/"
+    "Sunset_off_the_Massachusetts_coast_-_NOAA.jpg"
+)
+PHOTO_SHA256 = "be62f3289c9bf7b75af68cd6978021d54e8a531d5d4cc493f6e9fbf5e1ab74d3"
+
+# Ente's text model takes 77 token ids, padded with 0; its image model takes
+# a 256x256 RGB image.
+TOKEN_COUNT = 77
+IMAGE_SIZE = 256
+
+
+def download(url, sha256):
+    # Wikimedia refuses requests without a User-Agent.
+    request = urllib.request.Request(url, headers={"User-Agent": "quak"})
+    with urllib.request.urlopen(request) as response:
+        data = response.read()
+    digest = hashlib.sha256(data).hexdigest()
+    if digest != sha256:
+        raise SystemExit(f"{url} has sha256 {digest}, not {sha256}")
+    return data
+
+
+def ente_model(name, sha256):
+    return onnxruntime.InferenceSession(
+        download(f"https://models.ente.com/{name}", sha256),
+        providers=["CPUExecutionProvider"],
+    )
+
+
+def run(session, tensor):
+    (output,) = session.run(None, {session.get_inputs()[0].name: tensor})
+    embedding = output[0]
+    return embedding / np.linalg.norm(embedding)
+
+
+def text_embedding(session, tokenizer, query):
+    ids = tokenizer.encode(query).ids
+    ids += [0] * (TOKEN_COUNT - len(ids))
+    return run(session, np.array([ids], dtype=np.int32))
+
+
+def image_embedding(session, photo):
+    image = ImageOps.exif_transpose(Image.open(io.BytesIO(photo))).convert("RGB")
+    # Scale to cover IMAGE_SIZE x IMAGE_SIZE and crop the centre.
+    square = ImageOps.fit(image, (IMAGE_SIZE, IMAGE_SIZE), Image.Resampling.BILINEAR)
+    pixels = np.asarray(square, dtype=np.float32) / 255
+    return run(session, pixels.transpose(2, 0, 1)[np.newaxis])
+
+
+def numbers(embedding):
+    return ", ".join(str(value) for value in embedding)
+
+
+def write_categories(prompts, embeddings):
+    lines = [
+        "// Written by bin/clip-keyword-vectors; do not edit by hand.",
+        "//",
+        "// The Discover categories of Ente's photos app, in their order, from",
+        f"// {DISCOVER_PATH} in https://github.com/ente-io/ente",
+        f"// at commit {ENTE_COMMIT}. Each has the text",
+        f"// embedding Ente's CLIP text model ({TEXT_MODEL})",
+        "// gives its query, scaled to length 1. `showVideo` is false for a category",
+        "// that leaves out videos.",
+        "",
+        "export const DISCOVER_CATEGORIES = [",
+    ]
+    for prompt, embedding in zip(prompts, embeddings):
+        lines += [
+            "    {",
+            f"        title: {json.dumps(prompt['title'])},",
+            f"        query: {json.dumps(prompt['query'])},",
+            f"        minScore: {json.dumps(prompt['minScore'])},",
+            f"        showVideo: {json.dumps(prompt.get('showVideo', True))},",
+            f"        textEmbedding: [{numbers(embedding)}],",
+            "    },",
+        ]
+    lines.append("];")
+    with open("src/clip-keyword-vectors.ts", "w", encoding="utf-8") as file:
+        file.write("\n".join(lines) + "\n")
+
+
+def write_fixture(embedding):
+    with open("test/clip-keywords-sunset.json", "w", encoding="utf-8") as file:
+        file.write(
+            "{\n"
+            f'    "photo": {json.dumps(PHOTO_URL)},\n'
+            f'    "sha256": {json.dumps(PHOTO_SHA256)},\n'
+            f'    "embedding": [{numbers(embedding)}]\n'
+            "}\n"
+        )
+
+
+def main():
+    prompts = json.loads(download(DISCOVER_URL, DISCOVER_SHA256))["prompts"]
+    tokenizer = Tokenizer.from_str(
+        download(TOKENIZER_URL, TOKENIZER_SHA256).decode("utf-8")
+    )
+    text_model = ente_model(TEXT_MODEL, TEXT_MODEL_SHA256)
+    embeddings = [
+        text_embedding(text_model, tokenizer, prompt["query"]) for prompt in prompts
+    ]
+    write_categories(prompts, embeddings)
+
+    image_model = ente_model(IMAGE_MODEL, IMAGE_MODEL_SHA256)
+    write_fixture(image_embedding(image_model, download(PHOTO_URL, PHOTO_SHA256)))
+
+
+if __name__ == "__main__":
+    main()

bin/quak.ts

@@ -2,8 +2,9 @@
 
 import { stdout, stderr } from "node:process";
 import { input, password } from "@inquirer/prompts";
-import { Command } from "commander";
+import { Command, Option } from "commander";
 import envPaths from "env-paths";
+import { logLevel, logRequests, stderrLog, type Log } from "../src/cli-log.js";
 import { init } from "../src/crypto/index.js";
 import {
     type CliContext,
@@ -29,6 +30,9 @@ const paths = envPaths("quak", { suffix: "" });
 
 const program = new Command();
 
+// Program options, so they are taken before or after any command's name.
+// `-v` counts its repeats, the way commander's documentation counts a repeated
+// option.
 program
     .name("quak")
     .description("CLI for the Ente end-to-end encrypted photo service")
@@ -37,21 +41,46 @@ program
         "--cache-dir <path>",
         "Directory for the local metadata/content cache " +
             "(default: the per-user cache directory)",
-    );
+    )
+    .option(
+        "-v, --verbose",
+        "Log more on stderr: debug lines with -v, trace lines too with -vv",
+        (_value: string, previous: number) => previous + 1,
+        0,
+    )
+    .addOption(
+        new Option(
+            "-q, --quiet",
+            "Print nothing on stderr but the error a failing command exits with",
+        ).conflicts("verbose"),
+    )
+    .configureHelp({ showGlobalOptions: true });
+
+interface ProgramOptions {
+    cacheDir?: string;
+    verbose: number;
+    quiet?: boolean;
+}
+
+// The log for this run, at the level `-v` and `-q` ask for.
+const log = (): Log => {
+    const { verbose, quiet } = program.opts<ProgramOptions>();
+    return stderrLog(stderr, logLevel(verbose, quiet ?? false));
+};
 
 const context = (): CliContext => ({
     stdout,
-    stderr,
+    log: log(),
     sessionDir: paths.data,
-    cacheDir: program.opts<{ cacheDir?: string }>().cacheDir,
+    cacheDir: program.opts<ProgramOptions>().cacheDir,
-    loadSession,
+    loadSession: (path) => loadSession(path, logRequests(log())),
-    login: (opts) => Client.login(opts),
+    login: (opts) => Client.login({ ...opts, apiOptions: logRequests(log()) }),
     prompt: (message) => input({ message }),
     promptSecret: (message) => password({ message, mask: true }),
 });
 
 const run = (command: Promise<number>): Promise<void> =>
-    runCommand(command, stdout, stderr, (code) => process.exit(code));
+    runCommand(command, stdout, stderr, log(), (code) => process.exit(code));
 
 program
     .command("login")
@@ -78,14 +107,15 @@ program
 
 program
     .command("files")
-    .description("List files in a collection")
+    .description("List the files in a collection, or every file in the account")
-    .requiredOption(
+    .argument(
-        "--collection <id>",
+        "[collectionID]",
-        "Collection ID (from `quak collections`)",
+        "Collection ID (from `quak collections`); without it, every file " +
+            "is listed once",
     )
     .option("--json", "Output as JSON array")
-    .action((opts: { collection: string; json?: boolean }) =>
+    .action((collectionID: string | undefined, opts: { json?: boolean }) =>
-        run(filesCommand(context(), opts)),
+        run(filesCommand(context(), collectionID, opts)),
     );
 
 program
@@ -142,7 +172,10 @@ program
                 {
                     ...context(),
                     loadSession: (path) =>
-                        loadSession(path, { retry: UNATTENDED_RETRY_OPTIONS }),
+                        loadSession(
+                            path,
+                            logRequests(log(), UNATTENDED_RETRY_OPTIONS),
+                        ),
                 },
                 dir,
                 opts,

src/api/client.ts

@@ -36,6 +36,15 @@ export interface ApiClientOptions {
     retry?: RetryOptions;
     requestTimeoutMs?: number;
     downloadTimeoutMs?: number;
+    // Called once for each request sent, with the status of its response or
+    // the error it failed with, for a caller that logs requests. A request
+    // that is retried is reported once for each attempt.
+    onRequest?: (request: {
+        method: string;
+        url: string;
+        status?: number;
+        error?: unknown;
+    }) => void;
 }
 
 export interface StreamOptions {
@@ -159,6 +168,7 @@ export class ApiClient {
     private readonly retry: ResolvedRetryOptions;
     private readonly requestTimeoutMs: number;
     private readonly downloadTimeoutMs: number;
+    private readonly onRequest: NonNullable<ApiClientOptions["onRequest"]>;
     private token: string | undefined;
 
     constructor(opts?: ApiClientOptions) {
@@ -180,6 +190,7 @@ export class ApiClient {
             opts?.requestTimeoutMs ?? DEFAULT_REQUEST_TIMEOUT_MS;
         this.downloadTimeoutMs =
             opts?.downloadTimeoutMs ?? DEFAULT_DOWNLOAD_TIMEOUT_MS;
+        this.onRequest = opts?.onRequest ?? (() => {});
         this.token = opts?.authToken;
     }
 
@@ -214,6 +225,33 @@ export class ApiClient {
         return h;
     }
 
+    // Send one request and report it to `onRequest`, with the status of its
+    // response or the error it failed with. `reportedURL` is the URL given to
+    // `onRequest`, when that must not be the one sent.
+    private async send(
+        url: string,
+        init: RequestInit & { method: string },
+        reportedURL = url,
+    ): Promise<Response> {
+        let resp: Response;
+        try {
+            resp = await this._fetch(url, init);
+        } catch (err) {
+            this.onRequest({
+                method: init.method,
+                url: reportedURL,
+                error: err,
+            });
+            throw err;
+        }
+        this.onRequest({
+            method: init.method,
+            url: reportedURL,
+            status: resp.status,
+        });
+        return resp;
+    }
+
     private async throwIfError(resp: Response): Promise<void> {
         if (resp.ok) return;
         const requestID = resp.headers.get("x-request-id") ?? undefined;
@@ -257,7 +295,7 @@ export class ApiClient {
         const url = buildURL(this.apiOrigin, path, query);
         // A GET changes nothing, so it is retried under the full policy.
         return withRetry(async () => {
-            const resp = await this._fetch(url, {
+            const resp = await this.send(url, {
                 method: "GET",
                 headers: this.headers(),
                 signal: AbortSignal.timeout(this.requestTimeoutMs),
@@ -280,7 +318,7 @@ export class ApiClient {
         // 3xx status, which is not retried.
         return withRetry(
             async () => {
-                const resp = await this._fetch(url, {
+                const resp = await this.send(url, {
                     method: "POST",
                     headers: this.headers({
                         "Content-Type": "application/json",
@@ -321,16 +359,23 @@ export class ApiClient {
         // object at one key in one request, so replaying it either overwrites
         // the same bytes or lands them for the first time. There is no partial
         // state to protect, hence the full policy rather than the POST rule.
+        // It is reported without its query, which holds the upload's
+        // signature: a log keeps what it is given.
+        const { origin, pathname } = new URL(presignedURL);
         await withRetry(async () => {
-            const resp = await this._fetch(presignedURL, {
+            const resp = await this.send(
-                method: "PUT",
+                presignedURL,
-                headers: {
+                {
-                    "Content-Type": "application/octet-stream",
+                    method: "PUT",
-                    "Content-Length": String(data.length),
+                    headers: {
+                        "Content-Type": "application/octet-stream",
+                        "Content-Length": String(data.length),
+                    },
+                    body: data,
+                    signal: AbortSignal.timeout(this.requestTimeoutMs),
                 },
-                body: data,
+                origin + pathname,
-                signal: AbortSignal.timeout(this.requestTimeoutMs),
+            );
-            });
             if (!resp.ok) {
                 // An ApiError, not a bare Error: without the status on the
                 // error the upload path cannot be classified at all, and a
@@ -348,7 +393,7 @@ export class ApiClient {
         // Same replay and redirect rules as `postJSON`, for the same reasons.
         return withRetry(
             async () => {
-                const resp = await this._fetch(url, {
+                const resp = await this.send(url, {
                     method: "PUT",
                     headers: this.headers({
                         "Content-Type": "application/json",
@@ -394,7 +439,7 @@ export class ApiClient {
             // headers, when no bytes have arrived either.
             const deadline = idleDeadline(this.downloadTimeoutMs);
             try {
-                const resp = await this._fetch(url, {
+                const resp = await this.send(url, {
                     method: "GET",
                     headers: this.headers(),
                     signal: deadline.signal,

src/backup.ts

@@ -14,9 +14,9 @@
 //         YYYY/YYYY-MM/YYYY-MM-DD/
 //             YYYY-MM-DD.<fileID>.<ext>    the decrypted bytes (the save path)
 //             YYYY-MM-DD.<fileID>.json     per-file metadata sidecar, with
-//                                          the file's ML data and its
+//                                          the file's ML data, its
-//                                          original's EXIF, XMP and
+//                                          keywords, and its original's
-//                                          dimensions
+//                                          EXIF, XMP and dimensions
 //         collections/<name>/<title>       symlink to the original
 //         collections/<name>.json          per-collection metadata
 //         account.json                     the account's email and user ID
@@ -41,8 +41,9 @@
 //
 // With `verify`, each original already at its save path is hashed as the
 // download check hashes it, and one that does not match the content hash its
-// metadata records is removed and fetched again in the same run. What is put
+// metadata records is replaced once a matching copy is downloaded, in the same
-// back is hashed too, and recorded as failed if it still does not match.
+// run. Until then it stays as it is: a download that fails, or that does not
+// match either, leaves it in place and is recorded as failed.
 //
 // Resilience (issue #8): no per-file condition aborts the run. A failed
 // download, a failed symlink, or ML data missing because the ML data fetch
@@ -50,7 +51,9 @@
 // running attempt count, and the last-tried time, and the run continues.
 // A file the library could not decrypt is recorded there too, unless a copy of
 // it in another album decrypted; an album it could not decrypt is logged by ID
-// and listed in `result.undecryptableAlbums`, as its name is not known.
+// and listed in `result.undecryptableAlbums`, as its name is not known. An
+// album whose folder or JSON cannot be written is logged by name and
+// listed in `result.failedAlbums`, and the run goes on to the next album.
 // `result.failed` — and thus the CLI's exit code — stays non-zero while any
 // failure remains unresolved and clears once every one succeeds. Each run
 // reconciles the ledger against the files it attempted, so an entry for a file
@@ -59,7 +62,6 @@
 // code.
 
 import {
-    createReadStream,
     lstatSync,
     mkdirSync,
     readdirSync,
@@ -75,27 +77,35 @@ import { readFile } from "node:fs/promises";
 import { dirname, extname, join, relative, resolve } from "node:path";
 import lockfile from "proper-lockfile";
 
-import {
+import { clipKeywords } from "./clip-keywords.js";
-    chunkHashFinal,
-    chunkHashInit,
-    chunkHashUpdate,
-    init,
-} from "./crypto/index.js";
 import { removeLeftoverTempFiles } from "./download/index.js";
-import { sanitizeFileName, withExtension } from "./filename.js";
+import { describeError } from "./errors.js";
+import {
+    MAX_NAME_BYTES,
+    sanitizeFileName,
+    shortenKeepingExtension,
+    shortenToBytes,
+    withExtension,
+} from "./filename.js";
 import {
     copyAtomic,
     placeOriginal,
+    replaceOriginal,
     savePath,
     storedAtSavePath,
+    storedHash,
 } from "./library/content.js";
 import { representative } from "./library/records.js";
 import type { Undecryptable } from "./library/store.js";
 import { extractImageMetadata } from "./metadata-backup.js";
 import type { MLData } from "./mldata-fetch.js";
 import type { Collection, EnteFile, FileMetadata } from "./model/types.js";
+import { hasTransportCode } from "./retry.js";
 
-export type ProgressCallback = (message: string) => void;
+// Reports one line of the backup's progress. `level` is "error" when the line
+// reports something that failed, such as a file or an album, and is left out
+// for every other line.
+export type ProgressCallback = (message: string, level?: "error") => void;
 
 // The lock in a backup directory, as `lockBackupDirectory` returns it.
 export interface BackupLock {
@@ -143,9 +153,9 @@ export interface BackupResult {
     // Originals already at their save path and left untouched.
     skipped: number;
     // With `verify`, the originals already at their save path whose hash
-    // matched, those whose hash did not (each removed and fetched again), and
+    // matched, those whose hash did not (each replaced once a matching copy is
-    // those whose metadata records no hash (left as they are). All three are
+    // downloaded), and those whose metadata records no hash (left as they
-    // zero without `verify`.
+    // are). All three are zero without `verify`.
     verified: number;
     mismatched: number;
     unchecked: number;
@@ -158,6 +168,9 @@ export interface BackupResult {
     // The IDs of the albums the library could not decrypt, whose files it
     // could not list; the CLI exits non-zero while there are any.
     undecryptableAlbums: number[];
+    // The IDs of the albums whose folder or JSON this run could not write;
+    // the CLI exits non-zero while there are any.
+    failedAlbums: number[];
 }
 
 // The slice of the library that backup drives. `Library` implements it; a test
@@ -180,6 +193,15 @@ export interface BackupLibrary {
         fileID: number,
         destination: string,
     ): Promise<{ path: string; videoPath?: string }>;
+    // Fetch an original's bytes to `destination` through the content pool,
+    // a live photo as its image and its video beside it, even when the cache
+    // or the library's save path already holds it, and return where they
+    // landed. With `verify`, an original whose hash does not match is replaced
+    // with what this fetches.
+    fetchOriginal(
+        fileID: number,
+        destination: string,
+    ): Promise<{ path: string; videoPath?: string }>;
     thumbnail(fileID: number): Promise<{ path: string }>;
     // How many originals the backup works on at once: the limit of the
     // library's content pool.
@@ -191,6 +213,11 @@ export interface BackupLibrary {
     // A file's cached ML data, as `lib.mldata.forFile()` returns it, or
     // undefined when none is cached.
     mlData(fileID: number): Promise<MLData | undefined>;
+    // Why the ML data the last ML data fetch that succeeded got for a file did
+    // not decrypt, gunzip or parse, or undefined when it did or the fetch got
+    // none. A fetch still running does not change it. A fetch that fails
+    // leaves it as it was.
+    mlDataError(fileID: number): unknown;
 }
 
 type FailureClass = "transient" | "permanent" | "unknown";
@@ -219,11 +246,16 @@ const isPresent = (path: string): boolean => {
 
 // Best-effort classification for the ledger. Retryable server/network problems
 // are transient; refusals and local filesystem/decrypt errors are permanent;
-// anything else is unknown. Both the error code and message are inspected.
+// anything else is unknown. The error code and the error as `describeError`
+// gives it are inspected, and so is each errno on the error's cause chain,
+// where Node's `fetch` puts it. An error named `TimeoutError` is transient
+// whatever its message says, as `isRetryable` retries it: each of quak's
+// deadlines aborts with one, and the download's says only that it stalled.
 const classify = (err: unknown): FailureClass => {
+    if (hasTransportCode(err)) return "transient";
     const e = err as NodeJS.ErrnoException;
-    const text =
+    if (e?.name === "TimeoutError") return "transient";
-        `${e?.code ?? ""} ${err instanceof Error ? err.message : String(err)}`.toLowerCase();
+    const text = `${e?.code ?? ""} ${describeError(err)}`.toLowerCase();
     if (
         /timeout|timed out|econnreset|econnrefused|econnaborted|network|socket|eai_again|throttl|temporarily|429|500|502|503|504/.test(
             text,
@@ -241,9 +273,6 @@ const classify = (err: unknown): FailureClass => {
     return "unknown";
 };
 
-const errorMessage = (err: unknown): string =>
-    err instanceof Error ? err.message : String(err);
-
 // Ensure `linkPath` is a symlink to `target`, rebuilding a missing, wrong, or
 // non-symlink entry. Throws on failure (a directory in the way, no permission)
 // so the caller records it and moves on rather than aborting the run.
@@ -263,31 +292,46 @@ const rebuildSymlink = (linkPath: string, target: string): void => {
 // The on-disk names for the entries of one directory, in entry order. Each
 // name is used as is unless another entry would get the same name, ignoring
 // case (two names that differ only in case are one entry on a case-insensitive
-// file system); then every entry sharing it gets ` (<id>)`, before the
+// file system), or it is too long for a file name; then it gets ` (<id>)`,
-// extension when `beforeExtension` is set. A name with an ID added can match
+// right before the extension when `beforeExtension` is set. To fit, the part
-// another entry's own name (`IMG (6).JPG`), so this repeats until no name is
+// before the ID is cut short as far as it must be. When the extension leaves
-// shared. IDs are stable, so the names are too.
+// no room for the ID and the first character of the name, the extension is
+// cut short, and the part before the ID keeps that character and any bytes
+// the cut leaves over (see `shortenKeepingExtension`). With `withJSON`, each
+// entry also has the JSON file `<name>.json` beside it, as an album does: a
+// name then leaves room for `.json`, and one that is another entry's JSON name
+// gets its ID added too.
+// Two names with different IDs added never match, but one can match another
+// entry's own name (`IMG (6).JPG`), so this repeats until no name is shared.
+// IDs are stable, so the names are too.
 const uniqueNames = (
     entries: { id: number; name: string }[],
-    beforeExtension: boolean,
+    opts: { beforeExtension?: boolean; withJSON?: boolean },
 ): string[] => {
+    const maxBytes = MAX_NAME_BYTES - (opts.withJSON ? ".json".length : 0);
     const withID = (id: number, name: string): string => {
-        const ext = beforeExtension ? extname(name) : "";
+        const tag = ` (${id})`;
-        const stem = name.slice(0, name.length - ext.length);
+        return opts.beforeExtension
-        return `${stem} (${id})${ext}`;
+            ? shortenKeepingExtension(name, maxBytes, tag)
+            : shortenToBytes(name, maxBytes - Buffer.byteLength(tag)) + tag;
     };
     const names = entries.map((e) => e.name);
     const suffixed = new Set<number>();
     for (;;) {
         const counts = new Map<string, number>();
-        for (const name of names) {
+        const count = (name: string): void => {
             const key = name.toLowerCase();
             counts.set(key, (counts.get(key) ?? 0) + 1);
+        };
+        for (const name of names) {
+            count(name);
+            if (opts.withJSON) count(`${name}.json`);
         }
         let changed = false;
         for (const [i, { id, name }] of entries.entries()) {
             if (suffixed.has(i)) continue;
-            if (counts.get(name.toLowerCase()) === 1) continue;
+            const fits = Buffer.byteLength(name) <= maxBytes;
+            if (fits && counts.get(name.toLowerCase()) === 1) continue;
             names[i] = withID(id, name);
             suffixed.add(i);
             changed = true;
@@ -414,26 +458,6 @@ const saveLedger = (path: string, ledger: Map<number, FailureEntry>): void => {
     );
 };
 
-// The content hash of the original stored at `stored`, computed as the download
-// check computes it: over each file's bytes, read in chunks, and for a live
-// photo `<imageHash>:<videoHash>`.
-const storedHash = async (stored: {
-    path: string;
-    videoPath?: string;
-}): Promise<string> => {
-    await init();
-    const hashFile = async (path: string): Promise<string> => {
-        const state = chunkHashInit();
-        for await (const chunk of createReadStream(path)) {
-            chunkHashUpdate(state, chunk as Buffer);
-        }
-        return chunkHashFinal(state);
-    };
-    const hash = await hashFile(stored.path);
-    if (stored.videoPath === undefined) return hash;
-    return `${hash}:${await hashFile(stored.videoPath)}`;
-};
-
 // A file's EXIF, XMP and dimensions as its JSON holds them: what
 // `extractImageMetadata` found in its original, or why the original could not
 // be read.
@@ -470,12 +494,13 @@ const imageMetadataFor = async (
         const bytes = await readFile(originalPath);
         return { imageMetadata: extractImageMetadata(bytes) ?? {} };
     } catch (err) {
-        return { imageMetadataError: errorMessage(err) };
+        return { imageMetadataError: describeError(err) };
     }
 };
 
-// The file's JSON: its basic fields, its magic metadata, its ML data or the
+// The file's JSON: its basic fields, its magic metadata, its ML data without
-// reason the ML data is missing, and its image metadata.
+// the CLIP embedding and the keywords that embedding gives, or the reason the
+// ML data is missing, and its image metadata.
 const writeSidecar = (
     path: string,
     file: EnteFile,
@@ -491,7 +516,13 @@ const writeSidecar = (
     };
     if (file.magicMetadata) meta.magicMetadata = file.magicMetadata;
     if (file.pubMagicMetadata) meta.pubMagicMetadata = file.pubMagicMetadata;
-    if (ml.mlData) meta.mlData = ml.mlData;
+    if (ml.mlData) {
+        const { clip: _clip, ...mlDataWithoutClip } = ml.mlData;
+        meta.mlData = mlDataWithoutClip;
+        const isVideo = file.metadata.fileType === "video";
+        const keywords = clipKeywords(ml.mlData, isVideo);
+        if (keywords) meta.keywords = keywords;
+    }
     if (ml.mlDataError) meta.mlDataError = ml.mlDataError;
     if (image.imageMetadata) meta.imageMetadata = image.imageMetadata;
     if (image.imageMetadataError) {
@@ -610,7 +641,7 @@ const runLockedBackup = async (
         // and thumbnail both fail this run must not double its attempt count
         // or appear twice in errors.
         if (failedThisRun.has(fileID)) return;
-        const error = errorMessage(err);
+        const error = describeError(err);
         errors.push({ fileID, title, collection, error });
         const prior = ledger.get(fileID);
         ledger.set(fileID, {
@@ -634,7 +665,7 @@ const runLockedBackup = async (
     for (const record of lib.undecryptable()) {
         const error = `could not be decrypted: ${record.error}`;
         if (record.fileID === undefined) {
-            log(`FAILED album ${record.collectionID}: ${error}`);
+            log(`FAILED album ${record.collectionID}: ${error}`, "error");
             undecryptableAlbums.push(record.collectionID);
         } else if (scope.has(record.collectionID)) {
             const copies = memberships.get(record.fileID);
@@ -655,11 +686,13 @@ const runLockedBackup = async (
     // through the content cache/pools, as `Photo.download()` does, and fetch
     // the optional thumbnails; a present file is left as is. With `verify`, a
     // present original is hashed first, and one that does not match the hash
-    // its metadata records is removed and fetched like a missing one. One
+    // its metadata records is downloaded again and replaced by
-    // that cannot be read is recorded as failed and left where it is.
+    // `replaceOriginal`, which leaves it as it was when that download fails
-    // `storeOriginal` does this for one original, and records its failure.
+    // or does not match either. One that cannot be read is recorded as failed
+    // and left where it is. `storeOriginal` does this for one original, and
+    // records its failure.
     const storeOriginal = async (file: EnteFile): Promise<void> => {
-        let stored = storedAtSavePath(downloadDirectory, file);
+        const stored = storedAtSavePath(downloadDirectory, file);
         let mismatch = false;
         if (stored !== undefined && verify) {
             try {
@@ -673,15 +706,11 @@ const runLockedBackup = async (
                     );
                     mismatched++;
                     mismatch = true;
-                    rmSync(stored.path);
-                    if (stored.videoPath !== undefined) {
-                        rmSync(stored.videoPath);
-                    }
-                    stored = undefined;
                 }
             } catch (err) {
                 log(
-                    `FAILED verifying original ${file.metadata.title}: ${errorMessage(err)}`,
+                    `FAILED verifying original ${file.metadata.title}: ${describeError(err)}`,
+                    "error",
                 );
                 recordFailure(
                     file.id,
@@ -692,32 +721,31 @@ const runLockedBackup = async (
                 return;
             }
         }
-        if (stored !== undefined) {
+        if (stored !== undefined && !mismatch) {
             skipped++;
             return;
         }
         try {
             log(`Fetching original ${file.metadata.title} (${file.id})...`);
-            // A fetched original is written straight to its save path (a
+            if (mismatch) {
-            // live photo beside it); only one that was already cached
+                await replaceOriginal(downloadDirectory, file, (dest) =>
-            // elsewhere is copied.
+                    lib.fetchOriginal(file.id, dest),
-            const placed = await placeOriginal(
+                );
-                downloadDirectory,
+            } else {
-                file,
+                // A fetched original is written straight to its save path (a
-                (dest) => lib.original(file.id, dest),
+                // live photo beside it); only one that was already cached
-            );
+                // elsewhere is copied.
-            storedThisRun.add(file.id);
+                await placeOriginal(downloadDirectory, file, (dest) =>
-            // A copy from the cache is not checked as a download is and can
+                    lib.original(file.id, dest),
-            // hold the same bad bytes, so what is put back after a mismatch
-            // is hashed too. A bad copy stays where it is and the file fails.
-            if (mismatch && (await storedHash(placed)) !== file.metadata.hash) {
-                throw new Error(
-                    "the original put back does not match its content hash either",
                 );
             }
+            storedThisRun.add(file.id);
             downloaded++;
         } catch (err) {
-            log(`FAILED original ${file.metadata.title}: ${errorMessage(err)}`);
+            log(
+                `FAILED original ${file.metadata.title}: ${describeError(err)}`,
+                "error",
+            );
             recordFailure(
                 file.id,
                 file.metadata.title,
@@ -781,17 +809,18 @@ const runLockedBackup = async (
     // Phase 2: rebuild the derived views from the model. Sidecars first, for
     // every present original (this repairs stale ones), each with the file's
     // ML data once an ML data fetch has completed, and its image metadata.
-    // When the fetch fails, a file with no cached ML data gets the reason
+    // When the fetch got a file's ML data but could not decrypt, gunzip or
-    // instead and is recorded as failed. The next run fetches its ML data
+    // parse it, or when the fetch failed, a file with no cached ML data gets
-    // again because none is cached.
+    // the reason instead and is recorded as failed. The next run fetches its
+    // ML data again because none is cached.
     if (includeOriginals) {
-        let mlDataError: string | undefined;
+        let mlDataFailure: unknown;
         try {
             log("Fetching ML data...");
             await lib.fetchMLData();
         } catch (err) {
-            mlDataError = errorMessage(err);
+            mlDataFailure = err;
-            log(`FAILED ML data: ${mlDataError}`);
+            log(`FAILED ML data: ${describeError(err)}`, "error");
         }
         for (const file of distinct.values()) {
             if (lock.lost) throw lock.lost;
@@ -808,13 +837,19 @@ const runLockedBackup = async (
                 storedThisRun.has(file.id),
             );
             const mlData = await lib.mlData(file.id);
-            if (mlData === undefined && mlDataError !== undefined) {
+            const failure = lib.mlDataError(file.id) ?? mlDataFailure;
-                writeSidecar(path, file, { mlDataError }, image);
+            if (mlData === undefined && failure !== undefined) {
+                writeSidecar(
+                    path,
+                    file,
+                    { mlDataError: describeError(failure) },
+                    image,
+                );
                 recordFailure(
                     file.id,
                     file.metadata.title,
                     collectionName.get(file.collectionID) ?? "",
-                    new Error(`ML data: ${mlDataError}`),
+                    new Error("ML data", { cause: failure }),
                 );
             } else {
                 writeSidecar(path, file, { mlData }, image);
@@ -833,7 +868,7 @@ const runLockedBackup = async (
             id: c.id,
             name: sanitizeFileName(c.name, `collection-${c.id}`),
         })),
-        false,
+        { withJSON: true },
     );
     const albumDirNames = new Map(
         allCollections.map((c, i) => [c.id, dirNames[i]!]),
@@ -846,61 +881,77 @@ const runLockedBackup = async (
             downloadDirectory,
         );
     } catch (err) {
-        log(`FAILED removing old album directories: ${errorMessage(err)}`);
+        log(
+            `FAILED removing old album directories: ${describeError(err)}`,
+            "error",
+        );
     }
 
+    // An album whose folder or JSON cannot be written, such as one whose
+    // folder name is taken by a file the user put there, is logged and listed
+    // in the result, and the run goes on to the next album.
+    const failedAlbums: number[] = [];
     for (const c of collections) {
         if (lock.lost) throw lock.lost;
-        const colDirName = albumDirNames.get(c.id)!;
-        const colDir = join(collectionsDir, colDirName);
-        mkdirSync(colDir, { recursive: true });
-
-        // Every album links the one original, saved from the file's entry in
-        // `distinct`.
-        const files = filesByCollection.get(c.id) ?? [];
-        const links = files.flatMap((f) =>
-            linksFor(
-                f,
-                storedAtSavePath(downloadDirectory, distinct.get(f.id)!),
-            ),
-        );
-        const linkNames = uniqueNames(links, true);
         try {
-            removeStaleLinks(colDir, new Set(linkNames), downloadDirectory);
+            const colDirName = albumDirNames.get(c.id)!;
-        } catch (err) {
+            const colDir = join(collectionsDir, colDirName);
-            log(`FAILED removing old links in ${c.name}: ${errorMessage(err)}`);
+            mkdirSync(colDir, { recursive: true });
-        }
 
-        const metaFiles = files.map((f) => ({
+            // Every album links the one original, saved from the file's entry
-            id: f.id,
+            // in `distinct`.
-            metadata: f.metadata,
+            const files = filesByCollection.get(c.id) ?? [];
-        }));
+            const links = files.flatMap((f) =>
-        for (const [i, link] of links.entries()) {
+                linksFor(
-            if (!includeOriginals || link.target === undefined) continue;
+                    f,
-            const linkName = linkNames[i]!;
+                    storedAtSavePath(downloadDirectory, distinct.get(f.id)!),
+                ),
+            );
+            const linkNames = uniqueNames(links, { beforeExtension: true });
             try {
-                rebuildSymlink(
+                removeStaleLinks(colDir, new Set(linkNames), downloadDirectory);
-                    join(colDir, linkName),
-                    relative(colDir, link.target),
-                );
             } catch (err) {
                 log(
-                    `FAILED symlink ${c.name}/${linkName}: ${errorMessage(err)}`,
+                    `FAILED removing old links in ${c.name}: ${describeError(err)}`,
-                );
+                    "error",
-                recordFailure(
-                    link.file.id,
-                    link.file.metadata.title,
-                    c.name,
-                    err,
                 );
             }
-        }
 
-        writeAlbumJSON(
+            const metaFiles = files.map((f) => ({
-            join(collectionsDir, `${colDirName}.json`),
+                id: f.id,
-            c,
+                metadata: f.metadata,
-            metaFiles,
+            }));
-        );
+            for (const [i, link] of links.entries()) {
+                if (!includeOriginals || link.target === undefined) continue;
+                const linkName = linkNames[i]!;
+                try {
+                    rebuildSymlink(
+                        join(colDir, linkName),
+                        relative(colDir, link.target),
+                    );
+                } catch (err) {
+                    log(
+                        `FAILED symlink ${c.name}/${linkName}: ${describeError(err)}`,
+                        "error",
+                    );
+                    recordFailure(
+                        link.file.id,
+                        link.file.metadata.title,
+                        c.name,
+                        err,
+                    );
+                }
+            }
+
+            writeAlbumJSON(
+                join(collectionsDir, `${colDirName}.json`),
+                c,
+                metaFiles,
+            );
+        } catch (err) {
+            log(`FAILED album ${c.name}: ${describeError(err)}`, "error");
+            failedAlbums.push(c.id);
+        }
     }
 
     // Reconcile the ledger against what this run actually attempted: an entry
@@ -926,6 +977,7 @@ const runLockedBackup = async (
         failed: ledger.size,
         errors,
         undecryptableAlbums,
+        failedAlbums,
     };
 };
 

src/cli-commands.ts

@@ -4,7 +4,10 @@
 // code; a thrown error is left to the caller. Nothing here calls
 // `process.exit`: `bin/quak.ts` wires these to the command line, and `run` in
 // `cli-run.ts` prints a thrown error as one line and exits once output has
-// drained. Output must stay byte-identical (see `cli-output.ts`).
+// drained. Output must stay byte-identical (see `cli-output.ts`). Each line on
+// stderr goes through `ctx.log` at its level (see `cli-log.ts`). Every command
+// that exits non-zero logs a fatal line saying why; one that exits 1 because
+// files or albums failed logs it last, saying how many and where to look.
 
 import {
     copyFileSync,
@@ -33,14 +36,23 @@ import {
     originalName,
     thumbnailName,
 } from "./cli-output.js";
-import { freshCollections, freshFiles, freshFile } from "./cli-read.js";
+import { type Log, logRefresh } from "./cli-log.js";
+import {
+    cachedFilesByID,
+    freshCollections,
+    freshFiles,
+    freshFile,
+    freshFilesByID,
+} from "./cli-read.js";
 import { withExtension } from "./filename.js";
 import { runMetadataBackup } from "./metadata-backup.js";
+import type { Collection, EnteFile } from "./model/types.js";
 import { listMissingThumbnails, fixMissingThumbnails } from "./thumbnails.js";
 
 export interface CliContext {
     stdout: { write(text: string): unknown };
-    stderr: { write(text: string): unknown };
+    // Writes a line on stderr at a log level, if the run's level prints it.
+    log: Log;
     // Directory holding `session.json`.
     sessionDir: string;
     // The `--cache-dir` global, or undefined to let the library pick its
@@ -82,16 +94,16 @@ const requireSession = (ctx: CliContext): Client | undefined => {
     try {
         client = ctx.loadSession(sessionPath(ctx));
     } catch (err) {
-        ctx.stderr.write(
+        ctx.log("fatal", err instanceof Error ? err.message : String(err));
-            `${err instanceof Error ? err.message : err}\n` +
+        ctx.log(
-                `Run "quak logout" and then "quak login" to replace it.\n`,
+            "fatal",
+            `Run "quak logout" and then "quak login" to replace it.`,
         );
         return undefined;
     }
     if (!client) {
-        ctx.stderr.write(
+        ctx.log("fatal", `Not logged in. Run "quak login" first.`);
-            `Not logged in. Run "quak login" first.\nSession file: ${sessionPath(ctx)}\n`,
+        ctx.log("fatal", `Session file: ${sessionPath(ctx)}`);
-        );
         return undefined;
     }
     return client;
@@ -107,7 +119,7 @@ const parseID = (
 ): number | undefined => {
     const id = Number(text);
     if (/^[0-9]+$/.test(text) && Number.isSafeInteger(id)) return id;
-    ctx.stderr.write(`Invalid ${kind} ID: ${text}\n`);
+    ctx.log("fatal", `Invalid ${kind} ID: ${text}`);
     return undefined;
 };
 
@@ -123,17 +135,24 @@ const readLibraryClient = (client: Client): LibraryClient => ({
     contentSource: () => client.contentSource(),
 });
 
-// Open a library for a single point command: the aggressive background precache
+// Open a library for a single point command. The aggressive background
-// (issue #48) is off — a one-shot `collections` or `get` must not start
+// precache (issue #48) is off, because a one-shot `collections` or `get` must
-// downloading the whole account — and the refresh interval is long so no second
+// not start downloading the whole account. No refresh starts as the library
-// refresh fires mid-command.
+// opens or on a timer. Each command asks for the refresh it needs.
+// `collections` and `files` with a collection ID need none (issues #210 and
+// #217). Nor do `get` and `get-thumb` on an empty cache (issue #222). Nor does
+// `helper fix-missing-thumbnails --file` on an empty cache (issue #223). While
+// a refresh runs, each collection whose files it has fetched is logged, so a
+// large account shows progress rather than nothing.
 const openReadLibrary = (ctx: CliContext, client: Client): Promise<Library> =>
     Library.open({
         client: readLibraryClient(client),
         cacheDirectory: ctx.cacheDir,
-        refreshIntervalSeconds: 3600,
+        refreshOnOpen: false,
+        refreshIntervalSeconds: Infinity,
         precacheThumbnails: false,
         precacheOriginals: false,
+        onProgress: logRefresh(ctx.log),
     });
 
 export const loginCommand = async (ctx: CliContext): Promise<number> => {
@@ -142,7 +161,7 @@ export const loginCommand = async (ctx: CliContext): Promise<number> => {
     const password =
         process.env.QUAK_PASSWORD ?? (await ctx.promptSecret("Password"));
 
-    ctx.stderr.write("Authenticating...\n");
+    ctx.log("info", "Authenticating...");
     try {
         const client = await ctx.login({
             email,
@@ -153,11 +172,12 @@ export const loginCommand = async (ctx: CliContext): Promise<number> => {
 
         saveSession(ctx.sessionDir, client.toJSON());
         const info = client.whoami();
-        ctx.stderr.write(`Logged in as ${info.email} (user ${info.userID})\n`);
+        ctx.log("info", `Logged in as ${info.email} (user ${info.userID})`);
-        ctx.stderr.write(`Session saved to ${sessionPath(ctx)}\n`);
+        ctx.log("info", `Session saved to ${sessionPath(ctx)}`);
     } catch (err) {
-        ctx.stderr.write(
+        ctx.log(
-            `Login failed: ${err instanceof Error ? err.message : err}\n`,
+            "fatal",
+            `Login failed: ${err instanceof Error ? err.message : err}`,
         );
         return 1;
     }
@@ -179,7 +199,7 @@ export const whoamiCommand = async (ctx: CliContext): Promise<number> => {
 export const logoutCommand = async (ctx: CliContext): Promise<number> => {
     const path = sessionPath(ctx);
     if (!existsSync(path)) {
-        ctx.stderr.write("No session found.\n");
+        ctx.log("info", "No session found.");
         return 0;
     }
     await init();
@@ -197,16 +217,15 @@ export const logoutCommand = async (ctx: CliContext): Promise<number> => {
     }
     unlinkSync(path);
     if (failure === undefined) {
-        ctx.stderr.write("Session ended on the server.\n");
+        ctx.log("info", "Session ended on the server.");
     } else {
-        ctx.stderr.write(
+        ctx.log("fatal", `Could not end the session on the server: ${failure}`);
-            `Could not end the session on the server: ${failure}\n`,
-        );
     }
-    ctx.stderr.write("Session deleted.\n");
+    ctx.log("info", "Session deleted.");
     if (cacheDir !== undefined) {
-        ctx.stderr.write(
+        ctx.log(
-            `Cache directory ${cacheDir} still holds decrypted data; delete it to remove that data.\n`,
+            "warning",
+            `Cache directory ${cacheDir} still holds decrypted data; delete it to remove that data.`,
         );
     }
     return failure === undefined ? 0 : 1;
@@ -221,9 +240,10 @@ export const collectionsCommand = async (
     if (!client) return 3;
     const lib = await openReadLibrary(ctx, client);
     try {
-        // Force a server round-trip and list in enumeration order (issue #36
+        // Ask the server for the collection list alone and list it in its
-        // amendment, issue #52): the pre-library CLI printed current state in
+        // order (issue #36 amendment, issues #52 and #210): the pre-library
-        // this order, not the albums projection's newest-first order.
+        // CLI printed current state in this order, not the albums
+        // projection's newest-first order.
         const collections = await freshCollections(lib);
 
         if (opts.json) {
@@ -254,26 +274,32 @@ export const collectionsCommand = async (
     }
 };
 
+// Lists the files of the collection `collectionIDStr` names, or without it every
+// file in the account, each once (issue #211).
 export const filesCommand = async (
     ctx: CliContext,
-    opts: { collection: string; json?: boolean },
+    collectionIDStr: string | undefined,
+    opts: { json?: boolean },
 ): Promise<number> => {
     await init();
     const client = requireSession(ctx);
     if (!client) return 3;
-    const collectionID = parseID(ctx, "collection", opts.collection);
+    const collectionID =
-    if (collectionID === undefined) return 1;
+        collectionIDStr === undefined
+            ? undefined
+            : parseID(ctx, "collection", collectionIDStr);
+    if (collectionIDStr !== undefined && collectionID === undefined) return 1;
 
     const lib = await openReadLibrary(ctx, client);
     try {
-        // Force a server round-trip and list in enumeration order (issue #36
+        // Ask the server for current state (issue #36 amendment, issue #52).
-        // amendment, issue #52). Each file prints from its own decrypted
+        // Each file prints from its own decrypted metadata (raw title,
-        // metadata (raw title, microsecond creationTime) via cli-output, and in
+        // microsecond creationTime) via cli-output. The files print in the
-        // the pre-library CLI's enumeration order, not the projection's
+        // order `freshFiles` returns them, not the projection's newest-first
-        // newest-first order.
+        // order.
         const files = await freshFiles(lib, collectionID);
         if (!files) {
-            ctx.stderr.write(`Collection ${collectionID} not found\n`);
+            ctx.log("fatal", `Collection ${collectionID} not found`);
             return 1;
         }
 
@@ -307,40 +333,42 @@ export const getCommand = async (
     try {
         // Force a server round-trip so the file resolves against current state
         // (issue #36 amendment, issue #52).
-        const resolved = await freshFile(lib, fileID);
+        const file = await freshFile(lib, fileID);
-        if (!resolved) {
+        if (!file) {
-            ctx.stderr.write(`File ${fileID} not found\n`);
+            ctx.log("fatal", `File ${fileID} not found`);
             return 1;
         }
-        const { photo, file } = resolved;
 
-        const result = await photo.original();
+        const result = await lib.originalOf(file);
         // Default name is the file's own title, as the pre-library CLI used
         // (not the editedName-preferring projection title) (issue #52).
-        const outPath = opts.out ?? originalName(file);
         if (result.videoPath === undefined) {
+            const outPath = opts.out ?? originalName(file);
             copyFileSync(result.path, outPath);
-            ctx.stderr.write(`${result.bytes} bytes -> ${outPath}\n`);
+            ctx.log("info", `${result.bytes} bytes -> ${outPath}`);
             return 0;
         }
         // A live photo is written as its image and its video, each named after
         // the title with its own extension, as Ente's clients name them. With
         // --out, the image goes there and the video beside it.
-        const imageOut =
+        const imageExt = extname(result.path);
-            opts.out ?? withExtension(outPath, extname(result.path));
+        const videoExt = extname(result.videoPath);
-        const videoOut = withExtension(outPath, extname(result.videoPath));
+        const imageOut = opts.out ?? originalName(file, imageExt);
+        const videoOut =
+            opts.out === undefined
+                ? originalName(file, videoExt)
+                : withExtension(opts.out, videoExt);
         if (imageOut.toLowerCase() === videoOut.toLowerCase()) {
-            ctx.stderr.write(
+            ctx.log(
-                `File ${fileID} is a live photo, and its video would also be written to ${imageOut}\n`,
+                "fatal",
+                `File ${fileID} is a live photo, and its video would also be written to ${imageOut}`,
             );
             return 1;
         }
         copyFileSync(result.path, imageOut);
         copyFileSync(result.videoPath, videoOut);
-        ctx.stderr.write(
+        ctx.log("info", `${result.bytes} bytes -> ${imageOut}`);
-            `${result.bytes} bytes -> ${imageOut}\n` +
+        ctx.log("info", `${statSync(videoOut).size} bytes -> ${videoOut}`);
-                `${statSync(videoOut).size} bytes -> ${videoOut}\n`,
-        );
         return 0;
     } finally {
         await lib.close();
@@ -362,19 +390,18 @@ export const getThumbCommand = async (
     try {
         // Force a server round-trip so the file resolves against current state
         // (issue #36 amendment, issue #52).
-        const resolved = await freshFile(lib, fileID);
+        const file = await freshFile(lib, fileID);
-        if (!resolved) {
+        if (!file) {
-            ctx.stderr.write(`File ${fileID} not found\n`);
+            ctx.log("fatal", `File ${fileID} not found`);
             return 1;
         }
-        const { photo, file } = resolved;
 
-        const result = await photo.thumbnail();
+        const result = await lib.thumbnailOf(file);
         // Default name is thumb_<file's own title>, as the pre-library CLI
         // used (not the projection title) (issue #52).
         const outPath = opts.out ?? thumbnailName(file);
         copyFileSync(result.path, outPath);
-        ctx.stderr.write(`${result.bytes} bytes -> ${outPath}\n`);
+        ctx.log("info", `${result.bytes} bytes -> ${outPath}`);
         return 0;
     } finally {
         await lib.close();
@@ -394,11 +421,16 @@ export const backupMetadataCommand = async (
         // Refresh first so the dump holds current account state, not what the
         // cache last held; a failed refresh throws.
         await lib.fresh();
-        const { failedMLBatches } = await runMetadataBackup(lib, client, dir, {
+        const result = await runMetadataBackup(lib, client, dir, {
             exif: opts.exif || opts.all,
-            onProgress: (msg) => ctx.stderr.write(msg + "\n"),
+            onProgress: (msg, level) => ctx.log(level ?? "info", msg),
         });
-        return failedMLBatches > 0 ? 1 : 0;
+        if (result.filesWithMLDataError === 0) return 0;
+        ctx.log(
+            "fatal",
+            `quak: the ML data of ${result.filesWithMLDataError} file(s) could not be read; see mlDataError in their JSON in ${dir}`,
+        );
+        return 1;
     } finally {
         await lib.close();
     }
@@ -413,7 +445,7 @@ export const backupCommand = async (
     const client = requireSession(ctx);
     if (!client) return 3;
 
-    ctx.stderr.write("Starting backup...\n");
+    ctx.log("info", "Starting backup...");
     // The lock is taken before the library opens and starts its refresh, so a
     // run refused while another backup of `dir` runs sends no request.
     let lock: BackupLock;
@@ -421,7 +453,7 @@ export const backupCommand = async (
         lock = await lockBackupDirectory(dir);
     } catch (err) {
         if ((err as NodeJS.ErrnoException).code !== "ELOCKED") throw err;
-        ctx.stderr.write(`quak: ${(err as Error).message}\n`);
+        ctx.log("fatal", `quak: ${(err as Error).message}`);
         return 2;
     }
     try {
@@ -436,43 +468,48 @@ export const backupCommand = async (
             refreshIntervalSeconds: Infinity,
             precacheThumbnails: false,
             precacheOriginals: false,
+            onProgress: logRefresh(ctx.log),
         });
         try {
             const result = await lib.backup({
                 downloadDirectory: dir,
                 lock,
                 verify: opts.verify,
-                onProgress: (msg) => {
+                onProgress: (msg, level) => ctx.log(level ?? "info", msg),
-                    if (!opts.json) ctx.stderr.write(msg + "\n");
-                },
             });
 
             if (opts.json) {
                 ctx.stdout.write(JSON.stringify(result, null, 2) + "\n");
             } else {
-                ctx.stderr.write("\n--- Backup complete ---\n");
+                ctx.log("info", "\n--- Backup complete ---");
-                ctx.stderr.write(`  Total files: ${result.totalFiles}\n`);
+                ctx.log("info", `  Total files: ${result.totalFiles}`);
-                ctx.stderr.write(`  Downloaded:  ${result.downloaded}\n`);
+                ctx.log("info", `  Downloaded:  ${result.downloaded}`);
-                ctx.stderr.write(`  Skipped:     ${result.skipped}\n`);
+                ctx.log("info", `  Skipped:     ${result.skipped}`);
                 if (opts.verify) {
-                    ctx.stderr.write(`  Verified:    ${result.verified}\n`);
+                    ctx.log("info", `  Verified:    ${result.verified}`);
-                    ctx.stderr.write(`  Mismatched:  ${result.mismatched}\n`);
+                    ctx.log("info", `  Mismatched:  ${result.mismatched}`);
-                    ctx.stderr.write(`  Unchecked:   ${result.unchecked}\n`);
+                    ctx.log("info", `  Unchecked:   ${result.unchecked}`);
                 }
-                ctx.stderr.write(`  Failed:      ${result.failed}\n`);
+                ctx.log("info", `  Failed:      ${result.failed}`);
                 if (result.errors.length > 0) {
-                    ctx.stderr.write("\nFailed files:\n");
+                    ctx.log("error", "\nFailed files:");
                     for (const e of result.errors) {
-                        ctx.stderr.write(
+                        ctx.log(
-                            `  [${e.collection}] ${e.title} (id ${e.fileID}): ${e.error}\n`,
+                            "error",
+                            `  [${e.collection}] ${e.title} (id ${e.fileID}): ${e.error}`,
                         );
                     }
                 }
             }
 
-            return result.failed > 0 || result.undecryptableAlbums.length > 0
+            const albums =
-                ? 1
+                result.undecryptableAlbums.length + result.failedAlbums.length;
-                : 0;
+            if (result.failed === 0 && albums === 0) return 0;
+            ctx.log(
+                "fatal",
+                `quak: ${result.failed} file(s) and ${albums} album(s) failed; see ${join(dir, "failures.json")} and the FAILED lines`,
+            );
+            return 1;
         } finally {
             await lib.close();
         }
@@ -493,18 +530,19 @@ export const listMissingThumbnailsCommand = async (
         // Refresh first so files added since the cache was written are
         // checked; a failed refresh throws.
         await lib.fresh();
-        const missing = await listMissingThumbnails(lib, client, (msg) => {
+        const missing = await listMissingThumbnails(lib, client, (msg, level) =>
-            if (!opts.json) ctx.stderr.write(msg + "\n");
+            ctx.log(level ?? "info", msg),
-        });
+        );
 
         if (opts.json) {
             ctx.stdout.write(JSON.stringify(missing, null, 2) + "\n");
         } else {
             if (missing.length === 0) {
-                ctx.stderr.write("No missing thumbnails found.\n");
+                ctx.log("info", "No missing thumbnails found.");
             } else {
-                ctx.stderr.write(
+                ctx.log(
-                    `\n${missing.length} file(s) with missing thumbnails:\n`,
+                    "info",
+                    `\n${missing.length} file(s) with missing thumbnails:`,
                 );
                 for (const m of missing) {
                     ctx.stdout.write(
@@ -535,31 +573,37 @@ export const fixMissingThumbnailsCommand = async (
     }
     const lib = await openReadLibrary(ctx, client);
     try {
-        // Refresh first so files added since the cache was written are found;
+        let found: Map<number, { file: EnteFile; collection: Collection }>;
-        // a failed refresh throws.
+        if (fileIDs.length > 0) {
-        await lib.fresh();
+            found = await freshFilesByID(lib, fileIDs);
-        if (fileIDs.length === 0) {
+        } else {
-            ctx.stderr.write("Scanning for missing thumbnails...\n");
+            // Refresh first so files added since the cache was written are
-            const missing = await listMissingThumbnails(lib, client, (msg) => {
+            // checked; a failed refresh throws.
-                if (!opts.json) ctx.stderr.write(msg + "\n");
+            await lib.fresh();
-            });
+            ctx.log("info", "Scanning for missing thumbnails...");
+            const missing = await listMissingThumbnails(
+                lib,
+                client,
+                (msg, level) => ctx.log(level ?? "info", msg),
+            );
             fileIDs = missing.map((m) => m.fileID);
             if (fileIDs.length === 0) {
-                ctx.stderr.write("No missing thumbnails found.\n");
+                ctx.log("info", "No missing thumbnails found.");
                 return 0;
             }
-            ctx.stderr.write(`Found ${fileIDs.length} file(s) to fix.\n`);
+            ctx.log("info", `Found ${fileIDs.length} file(s) to fix.`);
+            found = cachedFilesByID(lib, fileIDs);
         }
 
         const results = await fixMissingThumbnails(
             lib,
             client,
             fileIDs,
-            (msg) => {
+            found,
-                if (!opts.json) ctx.stderr.write(msg + "\n");
+            (msg, level) => ctx.log(level ?? "info", msg),
-            },
         );
 
+        const failed = results.filter((r) => r.status === "failed").length;
         if (opts.json) {
             ctx.stdout.write(JSON.stringify(results, null, 2) + "\n");
         } else {
@@ -567,30 +611,30 @@ export const fixMissingThumbnailsCommand = async (
             const skipped = results.filter(
                 (r) => r.status === "skipped",
             ).length;
-            const failed = results.filter((r) => r.status === "failed").length;
+            ctx.log("info", `\n--- Done ---`);
-            ctx.stderr.write(`\n--- Done ---\n`);
+            ctx.log("info", `  Fixed:   ${fixed}`);
-            ctx.stderr.write(`  Fixed:   ${fixed}\n`);
+            ctx.log("info", `  Skipped: ${skipped}`);
-            ctx.stderr.write(`  Skipped: ${skipped}\n`);
+            ctx.log("info", `  Failed:  ${failed}`);
-            ctx.stderr.write(`  Failed:  ${failed}\n`);
             if (skipped > 0) {
-                ctx.stderr.write("\nSkipped:\n");
+                ctx.log("info", "\nSkipped:");
                 for (const r of results.filter((r) => r.status === "skipped")) {
-                    ctx.stderr.write(
+                    ctx.log("info", `  ${r.fileID}\t${r.title}\t${r.reason}`);
-                        `  ${r.fileID}\t${r.title}\t${r.reason}\n`,
-                    );
                 }
             }
             if (failed > 0) {
-                ctx.stderr.write("\nFailed files:\n");
+                ctx.log("error", "\nFailed files:");
                 for (const r of results.filter((r) => r.status === "failed")) {
-                    ctx.stderr.write(
+                    ctx.log("error", `  ${r.fileID}\t${r.title}\t${r.reason}`);
-                        `  ${r.fileID}\t${r.title}\t${r.reason}\n`,
-                    );
                 }
             }
         }
 
-        return results.some((r) => r.status === "failed") ? 1 : 0;
+        if (failed === 0) return 0;
+        ctx.log(
+            "fatal",
+            `quak: ${failed} file(s) failed; see the "Failed files:" list, or the JSON with --json`,
+        );
+        return 1;
     } finally {
         await lib.close();
     }

src/cli-log.ts

@@ -0,0 +1,99 @@
+// The CLI's log level, and the one function the commands write stderr lines
+// through.
+//
+// Every line quak prints on stderr is a log line at one of six levels, from
+// the quietest: fatal, error, warning, info, debug, trace. A run prints the
+// lines at its own level and at every quieter one. Its level is info unless
+// `-v` or `-q` asks for another (see "What quak prints" in the README). Every
+// command that exits non-zero logs a fatal line saying why, so even `-q`, which
+// prints only fatal lines, never leaves a non-zero exit unexplained. An error
+// line reports something that failed, such as a file or an album, and a
+// warning something that did not fail but needs the user's attention. stdout
+// carries only a command's output and is not a log.
+//
+// The library itself writes no lines: its layers report through callbacks, and
+// the CLI logs what they report. `logRequests` gives the API client options
+// that log each request and each retry, and `logRefresh` the library's
+// `onProgress` that logs what a refresh and an ML data fetch report.
+
+import type { ApiClientOptions } from "./api/client.js";
+import { describeError } from "./errors.js";
+import type { RefreshEvent } from "./library/index.js";
+import type { RetryOptions } from "./retry.js";
+
+const LEVELS = ["fatal", "error", "warning", "info", "debug", "trace"] as const;
+
+export type LogLevel = (typeof LEVELS)[number];
+
+// Writes `line` on stderr when the run's level prints lines at `level`.
+export type Log = (level: LogLevel, line: string) => void;
+
+// The level asked for by `-v` given `verbose` times, or by `-q`: info without
+// either, debug for `-v`, trace for `-vv` and more, fatal for `-q`.
+// `bin/quak.ts` refuses `-q` and `-v` together.
+export const logLevel = (verbose: number, quiet: boolean): LogLevel => {
+    if (quiet) return "fatal";
+    if (verbose === 0) return "info";
+    return verbose === 1 ? "debug" : "trace";
+};
+
+// The log that writes each line at `level` or quieter to `stderr`, ending it
+// with a newline.
+export const stderrLog =
+    (stderr: { write(text: string): unknown }, level: LogLevel): Log =>
+    (lineLevel, line) => {
+        if (LEVELS.indexOf(lineLevel) <= LEVELS.indexOf(level)) {
+            stderr.write(line + "\n");
+        }
+    };
+
+// API client options that log each request at trace, with the status of its
+// response or the error it failed with, and each retry at debug, with why and
+// how long it waits. `retry` is the retry policy, the default when not given.
+export const logRequests = (
+    log: Log,
+    retry?: RetryOptions,
+): ApiClientOptions => ({
+    retry: {
+        ...retry,
+        onRetry: (err, attempt, delayMs) =>
+            log(
+                "debug",
+                `Attempt ${attempt} failed, retrying in ${Math.round(delayMs)} ms: ${describeError(err)}`,
+            ),
+    },
+    onRequest: ({ method, url, status, error }) =>
+        log(
+            "trace",
+            `${method} ${url}: ${error === undefined ? `HTTP ${status}` : describeError(error)}`,
+        ),
+});
+
+// How a log line names each operation the library reports the start and end
+// of.
+const OPERATION_NAMES: Record<RefreshEvent["operation"], string> = {
+    refresh: "Refresh",
+    fetchMLData: "ML data fetch",
+    precacheThumbnails: "Thumbnail precache",
+    precacheOriginals: "Original precache",
+};
+
+// A library `onProgress` that logs, at info, each collection whose files a
+// refresh has fetched, and at debug the start and end of each refresh and ML
+// data fetch, with the error of one that failed.
+export const logRefresh =
+    (log: Log) =>
+    (event: RefreshEvent): void => {
+        if (event.status === "progress") {
+            log(
+                "info",
+                `Fetched the files of ${event.fetched} of ${event.total} collections`,
+            );
+            return;
+        }
+        const error = event.error === undefined ? "" : `: ${event.error}`;
+        log(
+            "debug",
+            `${OPERATION_NAMES[event.operation]} ${event.status}${error}`,
+        );
+    };

src/cli-output.ts

@@ -9,7 +9,7 @@
 // `metadata.title`, and issue #52 requires that output stay byte-identical, so
 // the commands shape their output from the raw `EnteFile` through here.
 
-import { sanitizeFileName } from "./filename.js";
+import { defaultFileName } from "./filename.js";
 import type { EnteFile, FileType, Microseconds } from "./model/types.js";
 
 // One row of `quak files --json`.
@@ -33,11 +33,13 @@ export const fileListRow = (file: EnteFile): FileListRow => ({
 export const fileListLine = (file: EnteFile): string =>
     `${file.id}\t${file.metadata.fileType}\t${file.metadata.title}`;
 
-// Default output path for `quak get` when `--out` is not given. The title comes
+// Default output path for `quak get` when `--out` is not given, made from the
-// from the server, so it is sanitized; `--out` is the user's and is used as is.
+// title (see `defaultFileName`), with `ext` in place of its extension for a
-export const originalName = (file: EnteFile): string =>
+// live photo's image or video; `--out` is the user's and is used as is.
-    sanitizeFileName(file.metadata.title, `file-${file.id}`);
+export const originalName = (file: EnteFile, ext?: string): string =>
+    defaultFileName(file.metadata.title, file.id, { ext });
 
-// Default output path for `quak get-thumb` when `--out` is not given.
+// Default output path for `quak get-thumb` when `--out` is not given: `thumb_`
+// and the title.
 export const thumbnailName = (file: EnteFile): string =>
-    `thumb_${originalName(file)}`;
+    defaultFileName(file.metadata.title, file.id, { prefix: "thumb_" });

src/cli-read.ts

@@ -1,62 +1,150 @@
 // How the CLI's read commands obtain current data.
 //
-// `collections`, `files --collection`, `get`, and `get-thumb` must answer for
+// `collections`, `files`, `get`, and `get-thumb` must answer for
 // the account's state at the moment the command runs, not for whatever the
-// local cache last happened to hold (owner amendment, issue #36). Each helper
+// local cache last happened to hold (owner amendment, issue #36). `get`,
-// therefore forces a server round-trip through `Library.fresh()` and only then
+// `get-thumb` and `files` without a collection ID therefore force a server
-// reads — so a collection, file, or metadata change made elsewhere is visible.
+// round-trip through `Library.fresh()` and only then read, so a change made
+// elsewhere is visible. `collections` asks the library for the collection list
+// alone through `Library.freshCollections()` (issue #210): a refresh would also
+// fetch the files of every collection, which on a large account takes long and
+// which `collections` does not print. `files` with a collection ID reads that
+// list too, then that one collection's files through `Library.freshFiles()`
+// (issue #217). On an empty cache, `get` and `get-thumb` read that list, then
+// one collection's files at a time, until they find the file (issue #222).
+// `helper fix-missing-thumbnails --file` does the same until it finds every
+// file it names (issue #223).
 //
-// `collections` and `files` also list in the library's own enumeration order —
+// `collections` and `files` with a collection ID list in the server's order.
-// `listCollections()`/`listFiles()`, the order the pre-library CLI printed —
+// `files` without one lists in the library's own enumeration order
-// rather than the `albums`/`photos` projection's newest-first order, which
+// (`listFiles()`). Neither command uses the `albums`/`photos` projection's
-// re-sorts the rows. The field values still come from each record's raw
+// newest-first order, which re-sorts the rows. The field values still come
-// metadata via `cli-output.ts`.
+// from each record's raw metadata via `cli-output.ts`. `files` without a
+// collection ID lists every file in the account once (issue #211): the library
+// keeps a record of a file for each collection that holds it, and only the
+// first collection's record is listed.
 
 import type { Collection, EnteFile } from "./model/types.js";
-import type { Photo, PhotosAPI } from "./library/index.js";
 
 // The slice of `Library` these helpers read. `Library` satisfies it
-// structurally; a test can drive them with a stand-in that records the
+// structurally; a test can drive them with a stand-in that records each fresh
-// `fresh()` call and serves records in a known enumeration order.
+// read and serves records in a known enumeration order.
 export interface FreshReadLibrary {
     fresh(): Promise<unknown>;
+    freshCollections(): Promise<Collection[]>;
+    freshFiles(collection: Collection): Promise<EnteFile[]>;
     listCollections(): Collection[];
-    getCollection(id: number): Collection | undefined;
     listFiles(collectionID: number): EnteFile[];
     getFileByID(fileID: number): EnteFile | undefined;
-    photos: Pick<PhotosAPI, "byID">;
 }
 
-// Every live collection, current as of a forced refresh, in enumeration order.
+// Every live collection, current as of one collections request, in the
-export const freshCollections = async (
+// server's order.
+export const freshCollections = (
     lib: FreshReadLibrary,
-): Promise<Collection[]> => {
+): Promise<Collection[]> => lib.freshCollections();
-    await lib.fresh();
-    return lib.listCollections();
-};
 
-// The files of one collection, current as of a forced refresh, in enumeration
+// The files of one collection, as the server holds them now, in the server's
 // order. `undefined` (not an empty list) when the collection does not exist, so
-// the caller can tell "no such collection" from "an empty collection".
+// the caller can tell "no such collection" from "an empty collection". Without
+// a collection ID, every file in the account as of a forced refresh, each once,
+// as held by the first collection that holds it.
 export const freshFiles = async (
     lib: FreshReadLibrary,
-    collectionID: number,
+    collectionID?: number,
 ): Promise<EnteFile[] | undefined> => {
+    if (collectionID !== undefined) {
+        const collections = await lib.freshCollections();
+        const collection = collections.find((c) => c.id === collectionID);
+        return collection ? lib.freshFiles(collection) : undefined;
+    }
     await lib.fresh();
-    if (!lib.getCollection(collectionID)) return undefined;
+    const listed = new Set<number>();
-    return lib.listFiles(collectionID);
+    const files: EnteFile[] = [];
+    for (const collection of lib.listCollections()) {
+        for (const file of lib.listFiles(collection.id)) {
+            if (listed.has(file.id)) continue;
+            listed.add(file.id);
+            files.push(file);
+        }
+    }
+    return files;
 };
 
-// One file, current as of a forced refresh, resolved to both its content
+// One file as the server holds it now, or `undefined` when no collection holds
-// handle (`Photo`, for fetching bytes) and its raw record (`EnteFile`, for the
+// it. When the cache holds the account's collections, it refreshes and looks
-// default output name and field values). `undefined` when the file is unknown.
+// the file up in the cache. On an empty cache, it reads the collection list,
+// then one collection's files at a time, and stops at the first collection
+// that holds the file. That search stores nothing.
 export const freshFile = async (
     lib: FreshReadLibrary,
     fileID: number,
-): Promise<{ photo: Photo; file: EnteFile } | undefined> => {
+): Promise<EnteFile | undefined> => {
-    await lib.fresh();
+    // Only a refresh stores collections, so a cache holding any holds them all.
-    const photo = lib.photos.byID({ fileID });
+    if (lib.listCollections().length > 0) {
-    const file = lib.getFileByID(fileID);
+        await lib.fresh();
-    if (!photo || !file) return undefined;
+        return lib.getFileByID(fileID);
-    return { photo, file };
+    }
+    for (const collection of await lib.freshCollections()) {
+        const files = await lib.freshFiles(collection);
+        const file = files.find((f) => f.id === fileID);
+        if (file) return file;
+    }
+    return undefined;
+};
+
+// The most recently updated collection first, and the higher ID first on a
+// tie. `Library.albums.list()` lists albums in this order.
+const byNewestCollection = (a: Collection, b: Collection): number =>
+    b.updationTime - a.updationTime || b.id - a.id;
+
+// Each file named by `fileIDs` that the cache holds, mapped to its record and
+// the collection it was found in. Collections are searched in
+// `byNewestCollection` order, and a file is found in the first that holds it.
+// So `helper fix-missing-thumbnails` names a file after the same album as
+// `helper list-missing-thumbnails`. It reads the cache alone, so the caller
+// refreshes first.
+export const cachedFilesByID = (
+    lib: FreshReadLibrary,
+    fileIDs: number[],
+): Map<number, { file: EnteFile; collection: Collection }> => {
+    const wanted = new Set(fileIDs);
+    const found = new Map<number, { file: EnteFile; collection: Collection }>();
+    const collections = [...lib.listCollections()].sort(byNewestCollection);
+    for (const collection of collections) {
+        for (const file of lib.listFiles(collection.id)) {
+            if (wanted.has(file.id) && !found.has(file.id)) {
+                found.set(file.id, { file, collection });
+            }
+        }
+    }
+    return found;
+};
+
+// Each file named by `fileIDs` as the server holds it now, mapped to its record
+// and collection as `cachedFilesByID` maps it. When the cache holds the
+// account's collections, it refreshes and looks the files up in the cache. On
+// an empty cache, it reads the collection list, then one collection's files at
+// a time, and stops once it has found every file. That search stores nothing.
+export const freshFilesByID = async (
+    lib: FreshReadLibrary,
+    fileIDs: number[],
+): Promise<Map<number, { file: EnteFile; collection: Collection }>> => {
+    // Only a refresh stores collections, so a cache holding any holds them all.
+    if (lib.listCollections().length > 0) {
+        await lib.fresh();
+        return cachedFilesByID(lib, fileIDs);
+    }
+    const wanted = new Set(fileIDs);
+    const found = new Map<number, { file: EnteFile; collection: Collection }>();
+    const collections = await lib.freshCollections();
+    for (const collection of [...collections].sort(byNewestCollection)) {
+        if (found.size === wanted.size) break;
+        for (const file of await lib.freshFiles(collection)) {
+            if (wanted.has(file.id) && !found.has(file.id)) {
+                found.set(file.id, { file, collection });
+            }
+        }
+    }
+    return found;
 };

src/cli-run.ts

@@ -2,18 +2,23 @@
 
 import type { Writable } from "node:stream";
 import { ApiError } from "./api/client.js";
+import type { Log } from "./cli-log.js";
+import { describeError } from "./errors.js";
 
 // Run a command and exit with its code once stdout/stderr have drained.
 // Exiting before the drain can truncate piped output, and the library can keep
 // the event loop alive after a command returns, so a plain return could hang.
-// An error the command throws is printed as one `quak: MESSAGE` line, without
+// An error the command throws is logged as one fatal `quak: MESSAGE` line,
-// the stack trace, and exits 1. A 401 from the server means it no longer
+// without the stack trace, and exits 1. MESSAGE is the error as
-// accepts the saved session: that prints one line saying to log in again and
+// `describeError` gives it, so it carries the reason Node's `fetch` puts on
-// exits 3, as a missing or corrupt session file does.
+// `cause`. A 401 from the server means it no longer accepts the saved session:
+// that logs one fatal line saying to log in again and exits 3, as a missing or
+// corrupt session file does.
 export const run = async (
     command: Promise<number>,
     stdout: Writable,
     stderr: Writable,
+    log: Log,
     exit: (code: number) => void,
 ): Promise<void> => {
     let code: number;
@@ -21,14 +26,13 @@ export const run = async (
         code = await command;
     } catch (err) {
         if (err instanceof ApiError && err.status === 401) {
-            stderr.write(
+            log(
-                `quak: the saved session is no longer valid; run "quak login"\n`,
+                "fatal",
+                `quak: the saved session is no longer valid; run "quak login"`,
             );
             code = 3;
         } else {
-            stderr.write(
+            log("fatal", `quak: ${describeError(err)}`);
-                `quak: ${err instanceof Error ? err.message : String(err)}\n`,
-            );
             code = 1;
         }
     }

src/client.ts

@@ -373,13 +373,17 @@ export class Client {
     }
 
     // Fetch machine-learning data (face detections + CLIP embeddings) for up
-    // to a batch of files, each decrypted with its own key. One request; the
+    // to a batch of files, each decrypted with its own key, and for each file
-    // library batches at `MLDATA_BATCH_SIZE` and schedules each batch through
+    // whose ML data did not decrypt, gunzip or parse, why not. One request;
-    // its metadata request pool.
+    // the library batches at `MLDATA_BATCH_SIZE` and schedules each batch
+    // through its metadata request pool.
     async fetchMLData(args: {
         fileIDs: number[];
         fileKeys: Map<number, Uint8Array>;
-    }): Promise<Map<number, MLData>> {
+    }): Promise<{
+        payloads: Map<number, MLData>;
+        errors: Map<number, unknown>;
+    }> {
         this.assertLoggedIn();
         return fetchMLDataBatch(this.api, args.fileIDs, args.fileKeys);
     }

src/clip-keywords.ts

@@ -0,0 +1,57 @@
+// Keywords for a file from its CLIP embedding.
+//
+// Ente stores no keywords. A file's ML data holds a CLIP embedding, the 512
+// numbers Ente's image model gave the photo, and Ente's photos app sorts files
+// into the categories of its Discover section with it: a file falls in a
+// category when the cosine similarity of its CLIP embedding and the text
+// embedding of the category's query is at least the category's `minScore`,
+// unless the file is a video and the category leaves out videos. A file's
+// keywords are the titles of the categories it falls in. The categories and
+// their text embeddings are in `clip-keyword-vectors.ts`.
+
+import { DISCOVER_CATEGORIES } from "./clip-keyword-vectors.js";
+import { clipEmbedding } from "./library/mldata.js";
+import type { MLData } from "./mldata-fetch.js";
+
+// How many numbers a CLIP embedding from Ente's image model has.
+const EMBEDDING_LENGTH = 512;
+
+const norm = (vector: number[]): number => Math.hypot(...vector);
+
+const cosineSimilarity = (a: number[], b: number[]): number => {
+    let dot = 0;
+    a.forEach((value, i) => {
+        dot += value * (b[i] ?? 0);
+    });
+    return dot / (norm(a) * norm(b));
+};
+
+// The titles of the Discover categories a file falls in, highest score first,
+// or undefined when its ML data has no CLIP embedding of 512 finite numbers
+// that are not all zero. Tests pass their own `categories`.
+export const clipKeywords = (
+    mlData: MLData,
+    isVideo: boolean,
+    categories = DISCOVER_CATEGORIES,
+): string[] | undefined => {
+    const embedding = clipEmbedding(mlData);
+    if (
+        !embedding ||
+        embedding.length !== EMBEDDING_LENGTH ||
+        norm(embedding) === 0
+    ) {
+        return undefined;
+    }
+
+    const matches: { title: string; score: number }[] = [];
+    for (const category of categories) {
+        if (isVideo && !category.showVideo) continue;
+        const score = cosineSimilarity(embedding, category.textEmbedding);
+        if (score >= category.minScore) {
+            matches.push({ title: category.title, score });
+        }
+    }
+    return matches
+        .sort((a, b) => b.score - a.score)
+        .map((match) => match.title);
+};

src/download/index.ts

@@ -16,7 +16,7 @@ import {
     streamTagFinal,
 } from "../crypto/index.js";
 import { TruncatedStreamError } from "../errors.js";
-import { safeExtension, sanitizeFileName, withExtension } from "../filename.js";
+import { defaultFileName, safeExtension, withExtension } from "../filename.js";
 import { withRetry } from "../retry.js";
 import type { ApiClient } from "../api/client.js";
 import type { EnteFile } from "../model/types.js";
@@ -135,15 +135,17 @@ const streamDecrypt = async (
                     // cannot tell a partial chunk from a corrupt one, so this
                     // is reported as the truncation it almost always is, with
                     // the authentication failure kept as the error's cause.
-                    // Only the pull is guarded: a sink failure on a chunk
+                    // The message leaves that failure to the cause, which
-                    // that did authenticate is a disk error, not a
+                    // `describeError` appends to what `quak backup` prints and
+                    // records. Only the pull is guarded: a sink failure on a
+                    // chunk that did authenticate is a disk error, not a
                     // truncation.
                     let pulled;
                     try {
                         pulled = pullStreamChunk(state, buffer);
                     } catch (err) {
                         throw new TruncatedStreamError(
-                            `download: stream truncated: response body ended with ${buffer.length} trailing bytes that did not authenticate as a final chunk (transfer stopped mid-chunk, or the data is corrupt)`,
+                            `download: stream truncated: response body ended with ${buffer.length} trailing bytes (transfer stopped mid-chunk, or the data is corrupt)`,
                             { cause: err },
                         );
                     }
@@ -197,11 +199,13 @@ const isRunning = (pid: number): boolean => {
 };
 
 // Delete the temp files a killed process left in `dir`: the writer's
-// `.quak-<pid>-<random>.tmp` and the backup copy's
+// `.quak-<pid>-<random>.tmp`, the backup copy's
-// `.quak-backup-<name>-<pid>-<random>.tmp`. Only files whose process is no
+// `.quak-backup-<name>-<pid>-<random>.tmp`, and the image and video of a live
-// longer running are removed, so another process writing into the same
+// photo downloaded to replace a stored one, `.quak-<pid>-<random>.<ext>` (see
-// directory keeps its own. A reused process ID can only keep a leftover a while
+// `replaceOriginal`). Only files whose process is no longer running are
-// longer, never remove a live one.
+// removed, so another process writing into the same directory keeps its own. A
+// reused process ID can only keep a leftover a while longer, never remove a
+// live one.
 export const removeLeftoverTempFiles = (dir: string): void => {
     let names: string[];
     try {
@@ -210,7 +214,9 @@ export const removeLeftoverTempFiles = (dir: string): void => {
         return;
     }
     for (const name of names) {
-        const match = /^\.quak-(?:.*-)?(\d+)-[0-9a-z]*\.tmp$/.exec(name);
+        const match = /^\.quak-(?:.*-)?(\d+)-[0-9a-z]*\.[0-9A-Za-z]+$/.exec(
+            name,
+        );
         if (match && !isRunning(Number(match[1]))) {
             rmSync(join(dir, name), { force: true });
         }
@@ -359,10 +365,14 @@ const openPart = async (
 // name starts with `image` as the image and the one whose name starts with
 // `video` as the video, and refuses a ZIP holding a second of either. It is
 // written unpacked: each part is named `destination` with the extension
-// replaced by its own entry's, and the two must differ ignoring case. When the
+// replaced by its own entry's, and the two must differ ignoring case. When
-// file records a hash, `<imageHash>:<videoHash>` must match it, each over that
+// `defaultName` is set, `destination` is the name `defaultFileName` made from
-// part's own bytes. Only then are the image, then the video, renamed into
+// the title rather than a path the caller gave, and each part is named as
-// place; on any failure neither is stored.
+// `defaultFileName` names it with its own extension, so that the name is cut
+// short to fit with that extension. When the file records a hash,
+// `<imageHash>:<videoHash>` must match it, each over that part's own bytes.
+// Only then are the image, then the video, renamed into place; on any failure
+// neither is stored.
 //
 // The ZIP is chosen by its uploader and may expand enormously, so each part is
 // written as it decompresses and never held, and the ZIP is refused once the
@@ -382,6 +392,7 @@ const decryptLivePhoto = async (
     key: Uint8Array,
     onProgress: ProgressCallback | undefined,
     file: EnteFile,
+    defaultName: boolean,
 ): Promise<DownloadResult> => {
     const sliceSize = 4096;
     const dir = dirname(destination);
@@ -480,8 +491,12 @@ const decryptLivePhoto = async (
                 `live photo's image and video have the same extension, ${video.ext}`,
             );
         }
-        const path = withExtension(destination, image.ext);
+        const partPath = (ext: string): string =>
-        const videoPath = withExtension(destination, video.ext);
+            defaultName
+                ? defaultFileName(file.metadata.title, file.id, { ext })
+                : withExtension(destination, ext);
+        const path = partPath(image.ext);
+        const videoPath = partPath(video.ext);
         for (const part of parts) {
             await part.handle.sync();
             await part.handle.close();
@@ -525,6 +540,9 @@ const decryptLivePhoto = async (
 // and then removes its own temp file, and only the attempt that reaches
 // TAG_FINAL renames one into place, so a download that needed three tries still
 // performs exactly one rename over the destination.
+//
+// `defaultName` says `destination` is the name `defaultFileName` made, not a
+// path the caller gave (see `decryptLivePhoto`).
 const fetchAndDecrypt = async (
     api: ApiClient,
     openStream: () => Promise<ReadableStream<Uint8Array>>,
@@ -533,6 +551,7 @@ const fetchAndDecrypt = async (
     destination: string,
     onProgress?: ProgressCallback,
     original?: EnteFile,
+    defaultName = false,
 ): Promise<DownloadResult> =>
     withRetry(async () => {
         const stream = await openStream();
@@ -545,6 +564,7 @@ const fetchAndDecrypt = async (
                     key,
                     onProgress,
                     original,
+                    defaultName,
                 );
             }
             const bytesWritten = await decryptToTemp(
@@ -576,10 +596,11 @@ export const downloadFile = async (
     outPath?: string,
     onProgress?: ProgressCallback,
 ): Promise<DownloadResult> => {
-    // `outPath` is the caller's and is used as is; the title is the server's
+    // `outPath` is the caller's and is used as is. Without it, the file is
-    // and is sanitized so it can only name a file in the current directory.
+    // written in the current directory under the name `defaultFileName` makes
+    // from the title, which is the server's.
     const resolvedPath =
-        outPath ?? sanitizeFileName(file.metadata.title, `file-${file.id}`);
+        outPath ?? defaultFileName(file.metadata.title, file.id);
     const header = fromBase64(file.file.decryptionHeader);
     return fetchAndDecrypt(
         api,
@@ -589,6 +610,7 @@ export const downloadFile = async (
         resolvedPath,
         onProgress,
         file,
+        outPath === undefined,
     );
 };
 
@@ -598,9 +620,10 @@ export const downloadThumbnail = async (
     outPath?: string,
     onProgress?: ProgressCallback,
 ): Promise<DownloadResult> => {
+    // As in `downloadFile`, with `thumb_` before the title.
     const resolvedPath =
         outPath ??
-        `thumb_${sanitizeFileName(file.metadata.title, `file-${file.id}`)}`;
+        defaultFileName(file.metadata.title, file.id, { prefix: "thumb_" });
     const header = fromBase64(file.thumbnail.decryptionHeader);
     return fetchAndDecrypt(
         api,

src/errors.ts

@@ -1,10 +1,13 @@
-// Error types that more than one layer of quak needs to recognise.
+// Error types that more than one layer of quak needs to recognise, and how an
+// error is described in what quak prints and in `failures.json`.
 //
-// They live here rather than beside the code that throws them so that the
+// The types live here rather than beside the code that throws them so that the
 // retry classifier can identify them without importing the HTTP client or the
 // download layer — both of which import the classifier. `ApiError` is
 // re-exported from `src/api/client.ts`, which is where callers have always
-// imported it from and where it still belongs conceptually.
+// imported it from and where it still belongs conceptually. The walk along an
+// error's `cause` chain is here too, because the retry classifier reads the
+// chain for errnos and `describeError` for messages.
 
 export class ApiError extends Error {
     readonly status: number;
@@ -43,3 +46,68 @@ export class TruncatedStreamError extends Error {
         this.name = "TruncatedStreamError";
     }
 }
+
+// `cause` is an arbitrary user-settable property and nothing prevents it from
+// forming a cycle, so the walk is bounded. Hanging the process would be worse
+// than misclassifying an error or describing only part of it.
+const MAX_CAUSE_DEPTH = 8;
+
+// The error and each error on its `cause` chain, top first, at most
+// `MAX_CAUSE_DEPTH` of them. `complete` is false when the walk stopped at the
+// depth limit with more of the chain still below it.
+export const causeChain = (
+    err: unknown,
+): { chain: object[]; complete: boolean } => {
+    const chain: object[] = [];
+    let current: unknown = err;
+    for (let depth = 0; depth < MAX_CAUSE_DEPTH; depth++) {
+        if (current === null || typeof current !== "object") {
+            return { chain, complete: true };
+        }
+        chain.push(current);
+        const { cause } = current as { cause?: unknown };
+        if (cause === current) return { chain, complete: true };
+        current = cause;
+    }
+    return { chain, complete: current === null || typeof current !== "object" };
+};
+
+// An error as quak prints it and records it in `failures.json`: its message,
+// then the message of each error on its `cause` chain, joined with ": ". Node's
+// `fetch` rejects with just "fetch failed" and puts the reason on `cause`, so
+// this gives "fetch failed: connect ECONNREFUSED 1.2.3.4:443". When the host
+// has several addresses and every one fails, the cause is an `AggregateError`
+// with an empty message and one error per address in `errors`, so an
+// `AggregateError` is given as the messages of its errors, joined with ", ".
+// A cause that is not an object, such as a thrown string, is given as
+// `String(cause)`. Each message is trimmed of the white space around it, as
+// OpenSSL ends its own with a newline. A message the text already holds is
+// left out.
+export const describeError = (err: unknown): string => {
+    if (!(err instanceof Error)) return String(err);
+    const { chain } = causeChain(err);
+    const messages = chain
+        .slice(1)
+        .map((cause) =>
+            cause instanceof AggregateError
+                ? cause.errors
+                      .map((e: unknown) =>
+                          (e instanceof Error ? e.message : String(e)).trim(),
+                      )
+                      .join(", ")
+                : (cause as { message?: unknown }).message,
+        );
+    // `causeChain` stops at a cause that is not an object, so that one is read
+    // from the last error on the chain.
+    const last = chain[chain.length - 1] as { cause?: unknown };
+    if (last.cause !== undefined && typeof last.cause !== "object") {
+        messages.push(String(last.cause));
+    }
+    let text = err.message.trim();
+    for (const message of messages) {
+        if (typeof message !== "string") continue;
+        const trimmed = message.trim();
+        if (!text.includes(trimmed)) text += `: ${trimmed}`;
+    }
+    return text;
+};

src/filename.ts

@@ -4,7 +4,10 @@
 // hands us, and quak does not trust the server. Any name taken from them and
 // used on disk goes through here, so it can only ever name one file inside the
 // directory the caller chose: never a path, never `..`, never hidden, never a
-// Windows device name.
+// Windows device name. Such a name can still be too long for a file name, and
+// `shortenToBytes` or `shortenKeepingExtension` cuts one short.
+// `defaultFileName` does both for the name a file is saved under when the
+// caller gives no path.
 //
 // A path the user typed (`--out`, `outPath`) is not passed through here: the
 // caller is trusted, the server is not.
@@ -29,13 +32,80 @@ export const sanitizeFileName = (name: string, fallback: string): string => {
     return RESERVED_DEVICE_NAME.test(cleaned) ? `_${cleaned}` : cleaned;
 };
 
-// The extension of `title` (".jpg"), or ".bin" when it has none or it holds
+// The extension of `title` (".jpg"), or ".bin" when it has none, it holds
-// anything but letters and digits.
+// anything but letters and digits, or it is more than 16 of them long.
 export const safeExtension = (title: string): string => {
     const ext = extname(title);
-    return /^\.[A-Za-z0-9]+$/.test(ext) ? ext : ".bin";
+    return /^\.[A-Za-z0-9]{1,16}$/.test(ext) ? ext : ".bin";
 };
 
 // `name` with its extension, if it has one, replaced by `ext` (".mov").
 export const withExtension = (name: string, ext: string): string =>
     name.slice(0, name.length - extname(name).length) + ext;
+
+// The longest file name, in bytes, that ext4 and most other file systems allow.
+export const MAX_NAME_BYTES = 255;
+
+// `name` cut short to at most `maxBytes` bytes of UTF-8, the encoding a file
+// name is written to disk in, between two characters, never inside one. A name
+// that fits comes back unchanged.
+export const shortenToBytes = (name: string, maxBytes: number): string => {
+    let bytes = 0;
+    let end = 0;
+    for (const character of name) {
+        bytes += Buffer.byteLength(character);
+        if (bytes > maxBytes) break;
+        end += character.length;
+    }
+    return name.slice(0, end);
+};
+
+// `name` cut short to fit in `maxBytes` bytes with `insert` put right before
+// its extension (`IMG_0001 (12).jpg`), each cut made as `shortenToBytes`
+// makes it. The part before the extension is cut first, so the extension is
+// kept whenever it fits, but that part always keeps its first character:
+// when the extension leaves no room for `insert` and that character, the
+// extension is cut short too, and the part before it keeps the bytes that cut
+// leaves over. So a name that does not start with a dot never comes back
+// starting with one, which would hide it. `insert` is never cut. With no
+// `insert`, a name that fits comes back unchanged.
+export const shortenKeepingExtension = (
+    name: string,
+    maxBytes: number,
+    insert = "",
+): string => {
+    const fullExt = extname(name);
+    const stem = name.slice(0, name.length - fullExt.length);
+    const first = Array.from(stem)[0] ?? "";
+    const ext = shortenToBytes(
+        fullExt,
+        maxBytes - Buffer.byteLength(insert + first),
+    );
+    const room = maxBytes - Buffer.byteLength(insert + ext);
+    return shortenToBytes(stem, room) + insert + ext;
+};
+
+// The name a file is saved under in the working directory when the caller
+// gives no path (`quak get` without `--out`, `downloadFile` without
+// `outPath`): `prefix` (`thumb_` for a thumbnail), then the file's title with
+// unsafe characters replaced, or `file-<id>` when the title is empty, cut
+// short so that the whole fits in a file name, keeping the title's extension
+// whenever it fits. `ext` (".mov"), when given, takes the place of the
+// title's extension before the name is cut short; a live photo's image and
+// video are each named with their own. The cut can leave a device name
+// (`CONSOLE.<long extension>` becomes `CON.<long extension>`); that name gets
+// a leading `_`, as `sanitizeFileName` gives one, and is cut a byte shorter to
+// leave room for it.
+export const defaultFileName = (
+    title: string,
+    fileID: number,
+    opts: { prefix?: string; ext?: string } = {},
+): string => {
+    const { prefix = "", ext } = opts;
+    const safe = sanitizeFileName(title, `file-${fileID}`);
+    const name = ext === undefined ? safe : withExtension(safe, ext);
+    const room = MAX_NAME_BYTES - Buffer.byteLength(prefix);
+    const cut = prefix + shortenKeepingExtension(name, room);
+    if (!RESERVED_DEVICE_NAME.test(cut)) return cut;
+    return `_${prefix}${shortenKeepingExtension(name, room - 1)}`;
+};

src/library/content.ts

@@ -13,6 +13,8 @@
 // originals, the thumbnail pool for thumbnails. The pool limits concurrency,
 // orders on-demand work ahead of background, and dedups by key so a fileID
 // requested twice while the first is still in flight downloads once.
+// `fetchOriginal` passes no key, so it is not shared with a fetch of the same
+// file already in flight.
 //
 // Integrity. The reused streaming decrypt is the enforced guarantee: every
 // chunk is authenticated and the writer renames the file into place only once
@@ -27,9 +29,10 @@
 // It also names each original's save path under the download directory
 // (`savePath`), where `Photo.download()` and `lib.backup()` put it. A copy in
 // the cache does not count as saved there, but is copied there rather than
-// fetched again.
+// fetched again. An original stored there whose bytes do not match its content
+// hash is replaced only by a download that does (`replaceOriginal`).
 
-import { existsSync, readFileSync, statSync } from "node:fs";
+import { createReadStream, existsSync, readFileSync, statSync } from "node:fs";
 import {
     chmod,
     copyFile,
@@ -44,6 +47,12 @@ import {
 import { basename, dirname, extname, join } from "node:path";
 
 import type { ApiClient } from "../api/client.js";
+import {
+    chunkHashFinal,
+    chunkHashInit,
+    chunkHashUpdate,
+    init,
+} from "../crypto/index.js";
 import {
     downloadFile,
     downloadThumbnail,
@@ -349,6 +358,26 @@ export const storedAtSavePath = (
     return storedOriginal(dirname(path), basename(path, extname(path)), file);
 };
 
+// The content hash of the original stored at `stored`, computed as the download
+// check computes it: over each file's bytes, read in chunks, and for a live
+// photo `<imageHash>:<videoHash>`.
+export const storedHash = async (stored: {
+    path: string;
+    videoPath?: string;
+}): Promise<string> => {
+    await init();
+    const hashFile = async (path: string): Promise<string> => {
+        const state = chunkHashInit();
+        for await (const chunk of createReadStream(path)) {
+            chunkHashUpdate(state, chunk as Buffer);
+        }
+        return chunkHashFinal(state);
+    };
+    const hash = await hashFile(stored.path);
+    if (stored.videoPath === undefined) return hash;
+    return `${hash}:${await hashFile(stored.videoPath)}`;
+};
+
 // Copy bytes into `dest` via a temp file in the same directory plus rename, so
 // `dest` appears only once it is whole ("present means complete"). As in the
 // download writer, the temp file is fsynced before the rename and the directory
@@ -405,6 +434,62 @@ export const placeOriginal = async (
     return { path, videoPath };
 };
 
+// Replace the original of `file` stored at its save path under `root` with a
+// new copy, keeping the stored one until the copy is complete and its hash,
+// computed as `storedHash` computes it, is the content hash the file's metadata
+// records. `get` is given a temporary file beside the save path and writes the
+// copy there, a live photo as its image and its video beside that file, each
+// with its own extension. Only a copy that matches is renamed over the stored
+// one, and a live photo's image and video are both hashed before either is
+// renamed. The image is renamed first: should the run stop, or the video's
+// rename fail, before the video is renamed, the new image is left beside the
+// old video, and a later backup with `verify` replaces the video if the video
+// was the part that did not match. When `get` fails or the copy does not match,
+// the temporary files are removed and the stored original stays as it was.
+export const replaceOriginal = async (
+    root: string,
+    file: EnteFile,
+    get: (dest: string) => Promise<{ path: string; videoPath?: string }>,
+): Promise<{ path: string; videoPath?: string }> => {
+    const dest = savePath(root, file);
+    const dir = dirname(dest);
+    // Named as the download writer names its temporary files; a live photo's
+    // image and video get this name with their own extensions. The next
+    // backup removes any that a killed run leaves (`removeLeftoverTempFiles`).
+    const tmp = join(
+        dir,
+        `.quak-${process.pid}-${Math.random().toString(36).slice(2)}.tmp`,
+    );
+    let got: { path: string; videoPath?: string } | undefined;
+    try {
+        got = await get(tmp);
+        if ((await storedHash(got)) !== file.metadata.hash) {
+            throw new Error(
+                "the downloaded original does not match its content hash either",
+            );
+        }
+        if (got.videoPath === undefined) {
+            await rename(got.path, dest);
+            await fsyncPath(dir);
+            return { path: dest };
+        }
+        const path = withExtension(dest, extname(got.path));
+        const videoPath = withExtension(dest, extname(got.videoPath));
+        await rename(got.path, path);
+        await rename(got.videoPath, videoPath);
+        const name = basename(dest, extname(dest));
+        await writeLivePhotoJSON(dir, name, { path, videoPath });
+        return { path, videoPath };
+    } finally {
+        // Whatever was not renamed into place. A failure to remove it must
+        // not replace the error that explains what went wrong.
+        for (const path of [tmp, got?.path, got?.videoPath]) {
+            if (path === undefined) continue;
+            await rm(path, { force: true }).catch(() => undefined);
+        }
+    }
+};
+
 export class ContentCache implements PhotoContent, ThumbnailsAPI {
     private readonly pools: RequestPools;
     private readonly source: ContentSource;
@@ -496,14 +581,34 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         fileID: number,
         opts?: ContentOptions,
     ): Promise<ContentResult> {
-        return this.get(fileID, "original", "on-demand", opts?.onProgress);
+        const file = this.fileOrThrow(fileID);
+        return this.get(file, "original", "on-demand", opts?.onProgress);
     }
 
     async thumbnail(
         fileID: number,
         opts?: ContentOptions,
     ): Promise<ContentResult> {
-        return this.get(fileID, "thumbnail", "on-demand", opts?.onProgress);
+        const file = this.fileOrThrow(fileID);
+        return this.get(file, "thumbnail", "on-demand", opts?.onProgress);
+    }
+
+    // The original of `file`, fetched and cached as `original` does. `file` is
+    // used as given, so `getFile` need not know it.
+    async originalOf(
+        file: EnteFile,
+        opts?: ContentOptions,
+    ): Promise<ContentResult> {
+        return this.get(file, "original", "on-demand", opts?.onProgress);
+    }
+
+    // The thumbnail of `file`, fetched and cached as `thumbnail` does. `file`
+    // is used as given, so `getFile` need not know it.
+    async thumbnailOf(
+        file: EnteFile,
+        opts?: ContentOptions,
+    ): Promise<ContentResult> {
+        return this.get(file, "thumbnail", "on-demand", opts?.onProgress);
     }
 
     // Put the original at the save path of `file` under the download directory
@@ -530,7 +635,7 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         destination: string,
     ): Promise<ContentResult> {
         const result = await this.acquire(
-            fileID,
+            this.fileOrThrow(fileID),
             "original",
             "on-demand",
             undefined,
@@ -543,6 +648,34 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         };
     }
 
+    // Fetch an original through the content pool to `destination`, a live
+    // photo as its image and its video beside it, and return where it landed.
+    // Unlike `backupOriginal`, it fetches even when the cache or the save path
+    // already holds the original, and it records nothing: what it writes is
+    // the caller's. It is not shared with a fetch of the same file already
+    // under way, which writes somewhere else.
+    async fetchOriginal(
+        fileID: number,
+        destination: string,
+    ): Promise<{ path: string; videoPath?: string }> {
+        const file = this.fileOrThrow(fileID);
+        return this.pools.content.run(
+            async () => {
+                const fetched = await this.fetchInto(
+                    file,
+                    destination,
+                    "original",
+                    undefined,
+                );
+                for (const path of [fetched.path, fetched.videoPath]) {
+                    if (path !== undefined) await chmod(path, FILE_MODE);
+                }
+                return fetched;
+            },
+            { priority: "on-demand" },
+        );
+    }
+
     async ensure(args: EnsureOptions): Promise<EnsureResult[]> {
         return this.ensureThumbnails(args);
     }
@@ -607,7 +740,8 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         onProgress: ((event: EnsureEvent) => void) | undefined,
     ): Promise<EnsureResult> {
         try {
-            const result = await this.acquire(fileID, kind, priority, signal);
+            const file = this.fileOrThrow(fileID);
+            const result = await this.acquire(file, kind, priority, signal);
             const status = result.cached ? "skipped" : "done";
             onProgress?.({ fileID, status, path: result.path });
             return { fileID, path: result.path };
@@ -622,8 +756,16 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         }
     }
 
+    // The record `getFile` gives for `fileID`. It throws for a file `getFile`
+    // does not know.
+    private fileOrThrow(fileID: number): EnteFile {
+        const file = this.getFile(fileID);
+        if (!file) throw new Error(`content cache: unknown file ${fileID}`);
+        return file;
+    }
+
     private async get(
-        fileID: number,
+        file: EnteFile,
         kind: Kind,
         priority: Priority,
         onProgress: ((event: ContentEvent) => void) | undefined,
@@ -631,7 +773,7 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         const onByte: ProgressCallback | undefined = onProgress
             ? (bytesDone) => onProgress({ status: "downloading", bytesDone })
             : undefined;
-        const result = await this.acquire(fileID, kind, priority, undefined, {
+        const result = await this.acquire(file, kind, priority, undefined, {
             onByte,
         });
         onProgress?.(
@@ -653,7 +795,7 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
     // photo's original is present only with its video, and is returned with
     // it.
     private async acquire(
-        fileID: number,
+        file: EnteFile,
         kind: Kind,
         priority: Priority,
         signal: AbortSignal | undefined,
@@ -664,8 +806,7 @@ export class ContentCache implements PhotoContent, ThumbnailsAPI {
         videoPath?: string;
         cached: boolean;
     }> {
-        const file = this.getFile(fileID);
+        const fileID = file.id;
-        if (!file) throw new Error(`content cache: unknown file ${fileID}`);
         const isLivePhoto =
             kind === "original" && file.metadata.fileType === "livePhoto";
 

src/library/index.ts

@@ -18,6 +18,17 @@
 // the caller (the default reads stay silent and serve the last good copy). The
 // default methods and the background loop are unchanged.
 //
+// `freshCollections()` is the fresh read of the collection list alone (issue
+// #210): one collections request, no collection's files, and nothing stored,
+// for a caller such as `quak collections` that needs no more. `freshFiles()`
+// is the fresh read of one collection's files, and stores nothing either
+// (issue #217). A caller that asks for each refresh it needs can also open the
+// library with `refreshOnOpen: false`, so that `open()` starts none.
+//
+// A refresh reports through `onProgress` each collection whose files it has
+// fetched, so a large account, whose first refresh fetches the files of every
+// collection, shows progress.
+//
 // A refresh stages all of its network work first and only mutates the store
 // once every fetch has succeeded. A refresh that fails partway therefore never
 // becomes visible to reads: the last good snapshot stays in place, and the
@@ -55,6 +66,8 @@ import {
     ContentCache,
     savePath,
     storedAtSavePath,
+    type ContentOptions,
+    type ContentResult,
     type ContentSource,
     type ThumbnailsAPI,
     type EnsureOptions,
@@ -89,6 +102,7 @@ export {
 } from "./content.js";
 export { type MLDataAPI, type SimilarResult } from "./mlsearch.js";
 import type { CollectionsPage, FilesPage } from "../client.js";
+import { describeError } from "../errors.js";
 import { MLDATA_BATCH_SIZE, type MLData } from "../mldata-fetch.js";
 import type { Collection, EnteFile } from "../model/types.js";
 import { runBackup, type BackupOptions, type BackupResult } from "../backup.js";
@@ -138,12 +152,16 @@ export interface LibraryClient {
         sinceTime: number;
     }): Promise<FilesPage>;
     // Fetch ML data (face detections + CLIP embeddings) for up to a batch of
-    // files. Optional: a client without it simply disables ML fetching, leaving
+    // files, and for each file whose ML data did not decrypt, gunzip or parse,
-    // the metadata refresh untouched.
+    // why not. Optional: a client without it simply disables ML fetching,
+    // leaving the metadata refresh untouched.
     fetchMLData?(args: {
         fileIDs: number[];
         fileKeys: Map<number, Uint8Array>;
-    }): Promise<Map<number, MLData>>;
+    }): Promise<{
+        payloads: Map<number, MLData>;
+        errors: Map<number, unknown>;
+    }>;
     // The byte source for the on-disk content cache. Optional so a mock client
     // that only serves metadata still satisfies the interface; when absent (and
     // no explicit `contentSource` is passed to `open`) the content cache is
@@ -154,7 +172,11 @@ export interface LibraryClient {
 // A progress event for one unit of background work. A metadata "refresh" or an
 // ML "fetchMLData" pass each fire "started" before their network work and then
 // exactly one of "done" or "failed"; "failed" carries the error message and
-// an ML "done" reports how many payloads it stored. The precache fills
+// an ML "done" reports how many payloads it stored and, in `mlDataErrors`,
+// each file whose ML data did not decrypt, gunzip or parse, with the reason.
+// In between, a refresh fires "progress" after each collection whose files it
+// fetched: `fetched` is how many collections it has fetched the files of so
+// far, `total` how many it will. The precache fills
 // ("precacheThumbnails"/"precacheOriginals", #48) fire "started"/"done" around
 // each sweep that has work, "done" reporting the count newly cached.
 export interface RefreshEvent {
@@ -163,9 +185,11 @@ export interface RefreshEvent {
         | "fetchMLData"
         | "precacheThumbnails"
         | "precacheOriginals";
-    status: "started" | "done" | "failed";
+    status: "started" | "progress" | "done" | "failed";
     error?: string;
     fetched?: number;
+    total?: number;
+    mlDataErrors?: { fileID: number; error: string }[];
 }
 
 export type RefreshProgressCallback = (event: RefreshEvent) => void;
@@ -184,6 +208,10 @@ export interface LibraryOptions {
     // `Infinity` starts none: the library then refreshes only as it opens and
     // when `fresh()` or `backup()` asks.
     refreshIntervalSeconds?: number;
+    // Whether `open()` starts a refresh. Defaults to true. With false, `open()`
+    // returns at once onto what the cache holds, empty or not, and a refresh
+    // starts only when `fresh()` or `backup()` asks or the timer fires.
+    refreshOnOpen?: boolean;
     onProgress?: RefreshProgressCallback;
     // The bounded request pools (issue #45), shared by the ML-data fetch (the
     // metadata pool) and the content cache. Defaults to a fresh set at the
@@ -225,6 +253,11 @@ export interface LibraryStatus {
     lastMLFetchAt?: number;
     // The most recent ML fetch pass's error, set only while it failed.
     lastMLError?: string;
+    // Each file whose ML data the last ML fetch pass that succeeded got but
+    // could not decrypt, gunzip or parse, with the reason. A pass still
+    // running leaves it as it is. A pass that fails leaves it as it was. Such
+    // ML data is not cached, so the next pass asks for it again.
+    mlDataErrors: { fileID: number; error: string }[];
     // ML payloads stored on disk and CLIP embeddings in the index; undefined
     // when ML fetching is disabled.
     mlStored?: number;
@@ -292,6 +325,12 @@ export class Library {
     private lastError?: string;
     private lastMLFetchAt?: number;
     private lastMLError?: string;
+    // For each file whose ML data the last ML fetch pass that succeeded got
+    // but could not decrypt, gunzip or parse, why not, by fileID. A pass
+    // gathers its own and puts them here when it ends without failing, so
+    // `status()` and `backup()` never see the list of a pass that is still
+    // running or that failed. Kept in RAM only, never in the cache.
+    private mlDataErrors = new Map<number, unknown>();
     // The plain-record projection as of the last refresh, and the GUI change
     // subscribers. A refresh that alters the projection notifies each with the
     // delta; `lastRecords` is kept current every refresh so a subscriber that
@@ -363,7 +402,8 @@ export class Library {
     // then opens empty with the failure recorded in `status()`. With an
     // existing cache the first refresh runs in the background and `open()`
     // returns as soon as the cached data is ready — an unreachable server does
-    // not block opening.
+    // not block opening. With `refreshOnOpen: false` there is no first
+    // refresh: `open()` returns onto the cache as it is.
     static async open(opts: LibraryOptions): Promise<Library> {
         const { userID } = opts.client.whoami();
         const cacheDirectory =
@@ -466,7 +506,10 @@ export class Library {
         // refresh.
         precache?.start();
 
-        if (store.loadedFromDisk) {
+        if (opts.refreshOnOpen === false) {
+            // The caller asks for each refresh it needs.
+            lib.scheduleNext();
+        } else if (store.loadedFromDisk) {
             // An existing copy already answers reads; refresh in the background
             // and start the interval once that first cycle settles.
             void lib.runRefresh().then(() => lib.scheduleNext());
@@ -542,6 +585,7 @@ export class Library {
             lastError: this.lastError,
             lastMLFetchAt: this.lastMLFetchAt,
             lastMLError: this.lastMLError,
+            mlDataErrors: this.describeMLDataErrors(),
             mlStored: ml?.stored,
             mlIndexed: ml?.indexed,
             originalsUsedBytes: originals?.usedBytes,
@@ -569,6 +613,69 @@ export class Library {
         };
     }
 
+    // The fresh read of the collection list alone (issue #210): every live
+    // collection that decrypts, in the server's order, from one collections
+    // request. Unlike a refresh, it fetches no collection's files, which on a
+    // large account take long. Nothing is stored: a refresh fetches a
+    // collection's files only when the collection is new or has changed since
+    // the stored copy, so a collection stored here without its files would
+    // never have them fetched.
+    async freshCollections(): Promise<Collection[]> {
+        if (this.closed) throw new Error("the library is closed");
+        const { collections } = await this.client.collectionsSince({
+            sinceTime: 0,
+        });
+        return collections;
+    }
+
+    // The fresh read of one collection's files (issue #217): every live file
+    // in it that decrypts, in the server's order. `collection` is a record
+    // `freshCollections()` returned, whose key decrypts the files. It fetches
+    // no other collection's files. Like `freshCollections()`, it stores
+    // nothing. It returns each file once, as the latest copy the server sent,
+    // where the first copy was.
+    async freshFiles(collection: Collection): Promise<EnteFile[]> {
+        if (this.closed) throw new Error("the library is closed");
+        const { files } = await this.client.filesSince({
+            collectionID: collection.id,
+            collectionKey: collection.key,
+            sinceTime: 0,
+        });
+        const byID = new Map<number, EnteFile>();
+        for (const file of files) byID.set(file.id, file);
+        return [...byID.values()];
+    }
+
+    // The original of `file`, fetched and cached as `Photo.original()` does.
+    // `file` is used as given, so the store need not hold it. On an empty
+    // cache, `quak get` passes a file that `freshFiles()` returned.
+    async originalOf(
+        file: EnteFile,
+        opts?: ContentOptions,
+    ): Promise<ContentResult> {
+        if (!this.cache) {
+            throw new Error(
+                "originalOf requires a library opened with a content cache",
+            );
+        }
+        return this.cache.originalOf(file, opts);
+    }
+
+    // The thumbnail of `file`, fetched and cached as `Photo.thumbnail()` does.
+    // `file` is used as given, so the store need not hold it. On an empty
+    // cache, `quak get-thumb` passes a file that `freshFiles()` returned.
+    async thumbnailOf(
+        file: EnteFile,
+        opts?: ContentOptions,
+    ): Promise<ContentResult> {
+        if (!this.cache) {
+            throw new Error(
+                "thumbnailOf requires a library opened with a content cache",
+            );
+        }
+        return this.cache.thumbnailOf(file, opts);
+    }
+
     // Back up every in-scope file to `opts.downloadDirectory`, or else the
     // library's, each original at its save path, with a durable failure
     // ledger (issue #51). Takes the lock in that directory first, unless the
@@ -606,10 +713,13 @@ export class Library {
                 undecryptable: () => this.store.listUndecryptable(),
                 original: (fileID, destination) =>
                     cache!.backupOriginal(fileID, destination),
+                fetchOriginal: (fileID, destination) =>
+                    cache!.fetchOriginal(fileID, destination),
                 thumbnail: (fileID) => cache!.thumbnail(fileID),
                 contentConcurrency: this.pools.content.concurrency,
                 fetchMLData: () => this.fetchMLDataNow(),
                 mlData: (fileID) => this.mldata.forFile({ fileID }),
+                mlDataError: (fileID) => this.mlDataErrors.get(fileID),
             },
             { ...opts, downloadDirectory },
         );
@@ -719,18 +829,28 @@ export class Library {
         // Stage per-collection file diffs. A collection's files are
         // re-enumerated only when its updationTime has advanced past the cached
         // copy; an unchanged album's file list cannot have changed. New
-        // collections enumerate from the beginning of time.
+        // collections enumerate from the beginning of time. Each collection
+        // whose files are fetched is reported, with how many there are to
+        // fetch.
+        const changedCollections = page.collections.filter((collection) => {
+            const known = this.store.getCollection(collection.id);
+            return !known || collection.updationTime > known.updationTime;
+        });
         const filePages: { collectionID: number; page: FilesPage }[] = [];
-        for (const collection of page.collections) {
+        for (const collection of changedCollections) {
             const known = this.store.getCollection(collection.id);
-            if (known && collection.updationTime <= known.updationTime)
-                continue;
             const filePage = await this.client.filesSince({
                 collectionID: collection.id,
                 collectionKey: collection.key,
                 sinceTime: known ? known.updationTime : 0,
             });
             filePages.push({ collectionID: collection.id, page: filePage });
+            this.emit({
+                operation: "refresh",
+                status: "progress",
+                fetched: filePages.length,
+                total: changedCollections.length,
+            });
         }
 
         // Network work done; commit to the store and persist only if something
@@ -836,8 +956,11 @@ export class Library {
 
     // One ML fetch pass: fetch, decrypt and store the ML data for every file
     // the store knows about that is not cached (or whose `updationTime` has
-    // advanced), through the metadata pool, and update the CLIP index. A
+    // advanced), through the metadata pool, and update the CLIP index. For a
-    // failure is reported through `status()` and `onProgress`, then thrown.
+    // file whose ML data does not decrypt, gunzip or parse, it gathers the
+    // reason instead, and puts the reasons it gathered in `mlDataErrors` when
+    // it ends without failing. A failure leaves `mlDataErrors` as it was and
+    // is reported through `status()` and `onProgress`, then thrown.
     private async runMLFetch(): Promise<void> {
         const mldata = this.mlStore;
         // Bind so the call keeps the client as its receiver when invoked
@@ -847,7 +970,14 @@ export class Library {
 
         const files = this.uniqueFiles();
         const needed = mldata.neededFor(files);
-        if (needed.length === 0) return;
+        // This pass's reasons, put in `this.mlDataErrors` when it ends without
+        // failing. A file whose ML data did not decode in the pass before is
+        // still among `needed`, so this pass gives its reason anew.
+        const mlDataErrors = new Map<number, unknown>();
+        if (needed.length === 0) {
+            this.mlDataErrors = mlDataErrors;
+            return;
+        }
 
         this.emit({ operation: "fetchMLData", status: "started" });
         try {
@@ -862,20 +992,25 @@ export class Library {
             for (let i = 0; i < needed.length; i += MLDATA_BATCH_SIZE) {
                 if (this.closed) break;
                 const batch = needed.slice(i, i + MLDATA_BATCH_SIZE);
-                const payloads = await this.pools.metadata.run(
+                const { payloads, errors } = await this.pools.metadata.run(
                     () => fetchMLData({ fileIDs: batch, fileKeys }),
                     { priority: "background" },
                 );
+                for (const [id, error] of errors) {
+                    mlDataErrors.set(id, error);
+                }
                 stored += (await mldata.storeFetched(payloads, updation))
                     .stored;
             }
 
+            this.mlDataErrors = mlDataErrors;
             this.lastMLFetchAt = Date.now();
             this.lastMLError = undefined;
             this.emit({
                 operation: "fetchMLData",
                 status: "done",
                 fetched: stored,
+                mlDataErrors: this.describeMLDataErrors(),
             });
         } catch (err) {
             const error = err instanceof Error ? err.message : String(err);
@@ -885,6 +1020,14 @@ export class Library {
         }
     }
 
+    // `mlDataErrors` as `status()` and the ML "done" event give it.
+    private describeMLDataErrors(): { fileID: number; error: string }[] {
+        return [...this.mlDataErrors].map(([fileID, err]) => ({
+            fileID,
+            error: describeError(err),
+        }));
+    }
+
     // The distinct files the store holds, one entry per fileID (a file in
     // several collections shares its ML data), each carrying the key and the
     // newest `updationTime` seen across its memberships.

src/library/mldata.ts

@@ -61,7 +61,7 @@ export interface MLIndex {
 // Pull the CLIP embedding out of a payload, or undefined when it is absent or
 // misshapen. Kept strict so a bad payload is skipped rather than corrupting the
 // packed index.
-const clipEmbedding = (payload: MLData): number[] | undefined => {
+export const clipEmbedding = (payload: MLData): number[] | undefined => {
     const clip = payload.clip;
     if (typeof clip !== "object" || clip === null) return undefined;
     const embedding = (clip as { embedding?: unknown }).embedding;

src/metadata-backup.ts

@@ -1,10 +1,16 @@
 import { mkdirSync, readFileSync, writeFileSync } from "node:fs";
 import { join } from "node:path";
 import * as jpeg from "jpeg-js";
+import { clipKeywords } from "./clip-keywords.js";
 import type { Client } from "./client.js";
+import { describeError } from "./errors.js";
 import { readExifTags } from "./exif.js";
 import type { Library, Photo } from "./library/index.js";
-import { sanitizeFileName } from "./filename.js";
+import {
+    MAX_NAME_BYTES,
+    sanitizeFileName,
+    shortenToBytes,
+} from "./filename.js";
 import {
     fetchMLDataBatch,
     MLDATA_BATCH_SIZE,
@@ -12,7 +18,10 @@ import {
 } from "./mldata-fetch.js";
 import type { EnteFile } from "./model/types.js";
 
-export type ProgressCallback = (message: string) => void;
+// Reports one line of the dump's progress. `level` is "error" when the line
+// reports ML data that could not be read, and is left out for every other
+// line.
+export type ProgressCallback = (message: string, level?: "error") => void;
 
 export interface MetadataBackupOptions {
     exif?: boolean;
@@ -89,16 +98,18 @@ const extractExif = async (
 
 // Dump every decrypted metadata layer the account holds into a directory tree
 // of plain JSON: account, per-collection, and per-file records including the
-// private and public magic metadata and (by default) the ML data. Collections
+// private and public magic metadata and the ML data, with the keywords of its
+// CLIP embedding in place of the embedding (see clip-keywords.ts). Collections
 // and files are enumerated from the library's cache, which the caller refreshes
-// first. Returns how many ML data requests failed; their files are still
+// first. Returns how many files have no ML data because their ML data request
+// failed or their ML data did not decrypt, gunzip or parse; they are still
 // written, with `mlDataError` in place of `mlData`.
 export const runMetadataBackup = async (
     lib: Library,
     client: Client,
     outDir: string,
     opts?: MetadataBackupOptions,
-): Promise<{ failedMLBatches: number }> => {
+): Promise<{ filesWithMLDataError: number }> => {
     const log = opts?.onProgress ?? (() => {});
     const wantExif = opts?.exif ?? false;
 
@@ -125,7 +136,15 @@ export const runMetadataBackup = async (
         const col = lib.getCollection(album.collectionID);
         if (!col) continue;
 
-        const dirName = `${col.id}-${sanitizeFileName(col.name, "unnamed")}`;
+        // The album's ID keeps the folders apart, so the name after it can be
+        // cut short to fit in a file name.
+        const prefix = `${col.id}-`;
+        const dirName =
+            prefix +
+            shortenToBytes(
+                sanitizeFileName(col.name, "unnamed"),
+                MAX_NAME_BYTES - prefix.length,
+            );
         const colDir = join(outDir, "collections", dirName);
         mkdirSync(colDir, { recursive: true });
 
@@ -164,26 +183,34 @@ export const runMetadataBackup = async (
     }
 
     // One failed request (retries exhausted) must not end the dump: its files
-    // get the reason in `mlDataError` and the other batches go on.
+    // get the reason in `mlDataError` and the other batches go on. So does a
+    // file whose ML data does not decrypt, gunzip or parse.
     log("Fetching ML data (face detections, CLIP embeddings)...");
     const mlDataMap = new Map<number, MLData>();
     const mlDataErrors = new Map<number, string>();
-    let failedMLBatches = 0;
     const fileIDs = [...fileKeys.keys()];
     for (let i = 0; i < fileIDs.length; i += MLDATA_BATCH_SIZE) {
         const batch = fileIDs.slice(i, i + MLDATA_BATCH_SIZE);
         try {
-            const result = await fetchMLDataBatch(
+            const { payloads, errors } = await fetchMLDataBatch(
                 client.getApiClient(),
                 batch,
                 fileKeys,
             );
-            for (const [id, payload] of result) mlDataMap.set(id, payload);
+            for (const [id, payload] of payloads) mlDataMap.set(id, payload);
+            for (const [id, err] of errors) {
+                const reason = describeError(err);
+                log(
+                    `ML data of file ${id} could not be read: ${reason}`,
+                    "error",
+                );
+                mlDataErrors.set(id, reason);
+            }
         } catch (err) {
             const reason = err instanceof Error ? err.message : String(err);
-            failedMLBatches++;
             log(
                 `ML data request for ${batch.length} file(s) failed: ${reason}`,
+                "error",
             );
             for (const id of batch) mlDataErrors.set(id, reason);
         }
@@ -205,8 +232,16 @@ export const runMetadataBackup = async (
         if (file.pubMagicMetadata)
             fileMeta.pubMagicMetadata = file.pubMagicMetadata;
 
+        // The ML data without the CLIP embedding, and the keywords that
+        // embedding gives.
         const ml = mlDataMap.get(file.id);
-        if (ml) fileMeta.mlData = ml;
+        if (ml) {
+            const { clip: _clip, ...mlDataWithoutClip } = ml;
+            fileMeta.mlData = mlDataWithoutClip;
+            const isVideo = file.metadata.fileType === "video";
+            const keywords = clipKeywords(ml, isVideo);
+            if (keywords) fileMeta.keywords = keywords;
+        }
         const mlError = mlDataErrors.get(file.id);
         if (mlError) fileMeta.mlDataError = mlError;
 
@@ -229,5 +264,5 @@ export const runMetadataBackup = async (
     }
 
     log("Metadata backup complete.");
-    return { failedMLBatches };
+    return { filesWithMLDataError: mlDataErrors.size };
 };

src/mldata-fetch.ts

@@ -28,43 +28,52 @@ interface RawRemoteFileData {
     updatedAt?: number;
 }
 
-// Decrypt one entry with its file key and gunzip the JSON payload. Returns
+// Decrypt one entry with its file key and gunzip the JSON payload. Throws why
-// undefined when the key is unknown or the entry does not decrypt/parse, so one
+// when the entry does not decrypt, gunzip or parse, or parses to something
-// corrupt file never fails a whole batch.
+// other than a JSON object, such as `null`, a number or an array.
-const decodeEntry = (
+const decodeEntry = (entry: RawRemoteFileData, key: Uint8Array): MLData => {
-    entry: RawRemoteFileData,
+    const decrypted = decryptBlob(
-    key: Uint8Array | undefined,
+        fromBase64(entry.encryptedData),
-): MLData | undefined => {
+        fromBase64(entry.decryptionHeader),
-    if (!key) return undefined;
+        key,
-    try {
+    );
-        const decrypted = decryptBlob(
+    const json = gunzipSync(Buffer.from(decrypted)).toString("utf-8");
-            fromBase64(entry.encryptedData),
+    const payload: unknown = JSON.parse(json);
-            fromBase64(entry.decryptionHeader),
+    if (
-            key,
+        typeof payload !== "object" ||
-        );
+        payload === null ||
-        const json = gunzipSync(Buffer.from(decrypted)).toString("utf-8");
+        Array.isArray(payload)
-        return JSON.parse(json) as MLData;
+    ) {
-    } catch {
+        throw new Error("not a JSON object");
-        return undefined;
     }
+    return payload as MLData;
 };
 
 // Fetch ML data for up to `MLDATA_BATCH_SIZE` ids in a single request. This is
 // the unit the request pools schedule; callers with more ids split them into
-// batches and submit each batch to the pool.
+// batches and submit each batch to the pool. Returns the payload of each file
+// whose entry decodes and, in `errors`, why not for each file whose entry does
+// not, so one corrupt file never fails a whole batch. An entry for a file
+// whose key is not known, which quak did not ask for, is skipped.
 export const fetchMLDataBatch = async (
     api: ApiClient,
     fileIDs: number[],
     fileKeys: Map<number, Uint8Array>,
-): Promise<Map<number, MLData>> => {
+): Promise<{ payloads: Map<number, MLData>; errors: Map<number, unknown> }> => {
     const { data } = await api.postJSON<{ data: RawRemoteFileData[] }>(
         "/files/data/fetch",
         { type: "mldata", fileIDs },
     );
-    const result = new Map<number, MLData>();
+    const payloads = new Map<number, MLData>();
+    const errors = new Map<number, unknown>();
     for (const entry of data ?? []) {
-        const payload = decodeEntry(entry, fileKeys.get(entry.fileID));
+        const key = fileKeys.get(entry.fileID);
-        if (payload) result.set(entry.fileID, payload);
+        if (!key) continue;
+        try {
+            payloads.set(entry.fileID, decodeEntry(entry, key));
+        } catch (err) {
+            errors.set(entry.fileID, err);
+        }
     }
-    return result;
+    return { payloads, errors };
 };

src/retry.ts

@@ -10,7 +10,7 @@
 // declining to retry a transient one costs a single file that the next run
 // picks up anyway. When the evidence is ambiguous, fail fast.
 
-import { ApiError, TruncatedStreamError } from "./errors.js";
+import { ApiError, causeChain, TruncatedStreamError } from "./errors.js";
 
 export interface RetryOptions {
     // Total calls, not retries: `attempts: 1` disables retrying.
@@ -24,6 +24,9 @@ export interface RetryOptions {
     sleep?: (ms: number) => Promise<void>;
     // Injected so the jitter is reproducible under test.
     random?: () => number;
+    // Called before each wait with the error that failed attempt number
+    // `attempt` and how long the wait is, for a caller that logs retries.
+    onRetry?: (err: unknown, attempt: number, delayMs: number) => void;
 }
 
 export type ResolvedRetryOptions = Required<RetryOptions>;
@@ -35,6 +38,7 @@ export const DEFAULT_RETRY_OPTIONS: ResolvedRetryOptions = {
     sleep: (ms: number): Promise<void> =>
         new Promise((resolve) => setTimeout(resolve, ms)),
     random: Math.random,
+    onRetry: () => {},
 };
 
 // For a run nobody is watching, such as `quak backup` from cron. A request that
@@ -55,9 +59,18 @@ export const resolveRetryOptions = (
     maxDelayMs: opts?.maxDelayMs ?? DEFAULT_RETRY_OPTIONS.maxDelayMs,
     sleep: opts?.sleep ?? DEFAULT_RETRY_OPTIONS.sleep,
     random: opts?.random ?? DEFAULT_RETRY_OPTIONS.random,
+    onRetry: opts?.onRetry ?? DEFAULT_RETRY_OPTIONS.onRetry,
 });
 
 // Transport failures: the request did not complete, for reasons below HTTP.
+//
+// The errnos are Node's. The binary `make install` builds runs under bun,
+// whose `fetch` rejects with a plain `Error` that has no `cause` and a `code`
+// of bun's own. Bun gives `ConnectionRefused` for a refused connection and for
+// a TLS handshake that failed, and `ConnectionRefused` or `FailedToOpenSocket`
+// for a name that does not resolve. For a connection reset or closed before
+// the response ended, it gives Node's `ECONNRESET`. These were found by
+// running that binary, built with bun 1.3.13, against listeners on 127.0.0.1.
 const TRANSPORT_CODES = new Set([
     "ECONNRESET",
     "ECONNABORTED",
@@ -70,6 +83,9 @@ const TRANSPORT_CODES = new Set([
     "ENETUNREACH",
     "ENETRESET",
     "ENETDOWN",
+    // Bun's.
+    "ConnectionRefused",
+    "FailedToOpenSocket",
 ]);
 
 // The subset of the above that can only be reported before a TCP connection
@@ -87,13 +103,14 @@ const TRANSPORT_CODES = new Set([
 // ambiguity this set exists to exclude. They stay in `TRANSPORT_CODES`, so
 // they remain retryable for idempotent calls; only replay eligibility is
 // narrowed. See `isSafeToReplay`.
+//
+// Bun's `ConnectionRefused` and `FailedToOpenSocket` are absent too, so a
+// `POST` or `PUT` is not replayed on them. When a connection bun kept open from
+// an earlier request closes before any answer, bun sends the request again on
+// a new connection, and if that one fails it gives one of these codes although
+// the server may already have the request.
 const CONNECT_CODES = new Set(["ENOTFOUND", "EAI_AGAIN", "ECONNREFUSED"]);
 
-// `cause` is an arbitrary user-settable property and nothing prevents it from
-// forming a cycle, so the walk is bounded. Hanging the process would be a
-// worse outcome than any misclassification.
-const MAX_CAUSE_DEPTH = 8;
-
 // Collect every `code` in an error's cause chain. undici does not put the
 // errno on the error it throws — it hangs the underlying socket error off
 // `cause`, sometimes more than one level down — so a classifier that only read
@@ -101,20 +118,21 @@ const MAX_CAUSE_DEPTH = 8;
 // connection permanent. `complete` is false when the walk stopped at the
 // depth limit with more of the chain still below it.
 const causeCodes = (err: unknown): { codes: string[]; complete: boolean } => {
+    const { chain, complete } = causeChain(err);
     const codes: string[] = [];
-    let current: unknown = err;
+    for (const link of chain) {
-    for (let depth = 0; depth < MAX_CAUSE_DEPTH; depth++) {
+        const { code } = link as { code?: unknown };
-        if (current === null || typeof current !== "object") {
-            return { codes, complete: true };
-        }
-        const { code, cause } = current as { code?: unknown; cause?: unknown };
         if (typeof code === "string") codes.push(code);
-        if (cause === current) return { codes, complete: true };
-        current = cause;
     }
-    return { codes, complete: current === null || typeof current !== "object" };
+    return { codes, complete };
 };
 
+// Does the error's cause chain hold the code of a transport failure, one of
+// `TRANSPORT_CODES`? `isRetryable` retries such an error, and `classify` in
+// `src/backup.ts` calls it transient.
+export const hasTransportCode = (err: unknown): boolean =>
+    causeCodes(err).codes.some((code) => TRANSPORT_CODES.has(code));
+
 const isAbort = (err: unknown): boolean => {
     if (err === null || typeof err !== "object") return false;
     const { name } = err as { name?: unknown };
@@ -156,9 +174,10 @@ export const isRetryable = (err: unknown): boolean => {
     // deliberately literal. Demanding a recognised `cause` instead would
     // classify real network failures as permanent and fail backups that should
     // have succeeded; the cost of the imprecision is bounded by the attempt
-    // count.
+    // count. Bun's fetch rejects with a plain `Error` instead, which is
+    // recognised by its code (see `TRANSPORT_CODES`).
     if (err instanceof TypeError) return true;
-    return causeCodes(err).codes.some((code) => TRANSPORT_CODES.has(code));
+    return hasTransportCode(err);
 };
 
 // Could the first attempt already have taken effect on the server?
@@ -174,11 +193,13 @@ export const isRetryable = (err: unknown): boolean => {
 //
 // Everything else is ambiguous. A 5xx proves the server did process the
 // request. A reset or a broken pipe can arrive after it was fully sent and
-// acted on. A routing errno can be delivered on an established socket. A
+// acted on. A routing errno can be delivered on an established socket. Bun's
-// deadline says nothing at all about the server's state. So every errno in the
+// `ConnectionRefused` and `FailedToOpenSocket` can come from a new connection
-// cause chain must be a connect errno: one other errno anywhere in the chain
+// bun opened to resend a request that already went out on a connection it kept
-// is doubt, and doubt is not replayed. A chain longer than the walk is doubt
+// open. A deadline says nothing at all about the server's state. So every code in the
-// too: the links below the limit were never read.
+// cause chain must be one of `CONNECT_CODES`: one other code anywhere in the
+// chain is doubt, and doubt is not replayed. A chain longer than the walk is
+// doubt too: the links below the limit were never read.
 export const isSafeToReplay = (err: unknown): boolean => {
     const { codes, complete } = causeCodes(err);
     return (
@@ -218,7 +239,9 @@ export const withRetry = async <T>(
                 // and its status intact.
                 throw err;
             }
-            await policy.sleep(backoffMs(attempt, policy));
+            const delayMs = backoffMs(attempt, policy);
+            policy.onRetry(err, attempt, delayMs);
+            await policy.sleep(delayMs);
         }
     }
 };

src/thumbnails.ts

@@ -5,7 +5,7 @@ import type { Client } from "./client.js";
 import type { Library } from "./library/index.js";
 import { ApiError } from "./api/client.js";
 import { encryptBlob, toBase64 } from "./crypto/index.js";
-import type { EnteFile } from "./model/types.js";
+import type { Collection, EnteFile } from "./model/types.js";
 
 // The server refuses a thumbnail larger than the one it already records for the
 // file (`thumbnail.size`, the encrypted size), so these encodings are tried
@@ -49,7 +49,10 @@ export interface ThumbnailFixResult {
     reason?: string;
 }
 
-export type ProgressCallback = (message: string) => void;
+// Reports one line of progress. `level` is "error" when the line reports a
+// file that could not be checked or fixed, and is left out for every other
+// line.
+export type ProgressCallback = (message: string, level?: "error") => void;
 
 // Enumerate every file the library knows about, newest album first, each file
 // once, and report those whose server-side thumbnail is missing. "Missing" is
@@ -111,6 +114,7 @@ export const listMissingThumbnails = async (
                 } else {
                     log(
                         `[${album.name}] Could not check ${photo.title}: ${err instanceof Error ? err.message : String(err)} (not reported as missing)`,
+                        "error",
                     );
                 }
             }
@@ -222,16 +226,18 @@ const encryptThumbnailWithin = (
     return undefined;
 };
 
-// Regenerate and upload a thumbnail for each requested file. Originals are read
+// Regenerate and upload a thumbnail for each requested file. `found` holds the
-// through the library's content cache (`photo.original()`); the generated
+// record of each requested file that a collection holds, and the collection it
-// thumbnail is JPEG-encoded, encrypted under the file's own key, and registered
+// was found in. Each original is read through the library's content cache, by
-// with the server — the encrypt-and-upload path is unchanged. Each file is
+// `lib.originalOf(file)`. The new thumbnail is a JPEG, encrypted under the
+// file's own key. It is uploaded, then registered with the server. Each file is
 // resolved to one outcome (fixed / skipped / failed) and a failure on one file
 // never stops the others.
 export const fixMissingThumbnails = async (
     lib: Library,
     client: Client,
     fileIDs: number[],
+    found: Map<number, { file: EnteFile; collection: Collection }>,
     onProgress?: ProgressCallback,
 ): Promise<ThumbnailFixResult[]> => {
     const log = onProgress ?? (() => {});
@@ -239,31 +245,8 @@ export const fixMissingThumbnails = async (
     const api = client.getApiClient();
     const { userID } = client.whoami();
 
-    // Resolve each requested fileID to its file record and owning album by
-    // enumerating the library, each file taken from the first album that holds
-    // it. The raw `EnteFile` carries the per-file key the thumbnail is
-    // encrypted under, which the projected records deliberately do not.
-    const wanted = new Set(fileIDs);
-    const fileMap = new Map<
-        number,
-        { file: EnteFile; collectionName: string }
-    >();
-    for (const album of lib.albums.list()) {
-        for (const photo of album.photos.list()) {
-            if (!wanted.has(photo.fileID) || fileMap.has(photo.fileID))
-                continue;
-            const file = lib.getFile(album.collectionID, photo.fileID);
-            if (file) {
-                fileMap.set(photo.fileID, {
-                    file,
-                    collectionName: album.name,
-                });
-            }
-        }
-    }
-
     for (const fileID of fileIDs) {
-        const entry = fileMap.get(fileID);
+        const entry = found.get(fileID);
         if (!entry) {
             results.push({
                 fileID,
@@ -275,7 +258,8 @@ export const fixMissingThumbnails = async (
             continue;
         }
 
-        const { file, collectionName } = entry;
+        const { file } = entry;
+        const collectionName = entry.collection.name;
         const title = file.metadata.title;
 
         const skipReason = reasonToSkip(file, userID);
@@ -293,15 +277,10 @@ export const fixMissingThumbnails = async (
         const maxSize = file.thumbnail.size!;
 
         try {
-            const photo = lib.photos.byID({ fileID });
-            if (!photo) {
-                throw new Error("file not present in the library cache");
-            }
-
             log(
                 `[${collectionName}] Downloading ${title} for thumbnail generation...`,
             );
-            const { path } = await photo.original();
+            const { path } = await lib.originalOf(file);
             const fileBytes = new Uint8Array(readFileSync(path));
 
             if (!isJpeg(fileBytes)) {
@@ -359,6 +338,7 @@ export const fixMissingThumbnails = async (
         } catch (err) {
             log(
                 `[${collectionName}] FAILED ${title}: ${err instanceof Error ? err.message : err}`,
+                "error",
             );
             results.push({
                 fileID,

test/api/client.test.ts

@@ -1222,3 +1222,65 @@ describe("ApiClient non-idempotent requests", () => {
         }
     });
 });
+
+// `onRequest` hears of each request the client sends, as its response arrives
+// or as it fails. The CLI logs these with `-vv`. A retried request is reported
+// once for each attempt.
+describe("ApiClient onRequest", () => {
+    it("reports each request with its status, or with the error it failed with", async () => {
+        const refused = new TypeError("fetch failed");
+        const { fetch } = scriptedFetch(
+            refused,
+            textResponse("unavailable", 503),
+            jsonResponse({ collections: [] }),
+            jsonResponse({}),
+            streamResponse(new Uint8Array([1, 2, 3])),
+        );
+        const requests: unknown[] = [];
+        const client = new ApiClient({
+            fetch,
+            retry: noWait,
+            onRequest: (request) => requests.push(request),
+        });
+
+        await client.getJSON("/collections/v2", { sinceTime: 0 });
+        await client.postJSON("/users/logout", {});
+        await readAll(await client.getFileStream(7));
+
+        const collections = "https://api.ente.io/collections/v2?sinceTime=0";
+        expect(requests).toEqual([
+            { method: "GET", url: collections, error: refused },
+            { method: "GET", url: collections, status: 503 },
+            { method: "GET", url: collections, status: 200 },
+            {
+                method: "POST",
+                url: "https://api.ente.io/users/logout",
+                status: 200,
+            },
+            {
+                method: "GET",
+                url: "https://files.ente.io/?fileID=7",
+                status: 200,
+            },
+        ]);
+    });
+
+    it("reports a presigned upload without its query, which holds the upload's signature", async () => {
+        const { fetch } = scriptedFetch(new Response(null, { status: 200 }));
+        const requests: unknown[] = [];
+        const client = new ApiClient({
+            fetch,
+            retry: noWait,
+            onRequest: (request) => requests.push(request),
+        });
+
+        await client.putFile(
+            "https://s3.example/obj?X-Amz-Signature=abc",
+            new Uint8Array([1, 2]),
+        );
+
+        expect(requests).toEqual([
+            { method: "PUT", url: "https://s3.example/obj", status: 200 },
+        ]);
+    });
+});

test/cli/backup-end-to-end.test.ts

@@ -9,7 +9,7 @@
  * data this file encrypts with libsodium, as Ente's clients encrypt it. So
  * quak's own code fetches each original, decrypts it, checks it against the
  * hash its uploader recorded and unpacks a live photo, and quak's own retries
- * repeat a failed request. Two tests run `lib.backup()` instead, as a program
+ * repeat a failed request. Three tests run `lib.backup()` instead, as a program
  * using quak as a library does.
  *
  * The account, user 42, has three albums:
@@ -54,6 +54,7 @@ import {
     saveSession,
     type CliContext,
 } from "../../src/cli-commands.js";
+import { stderrLog } from "../../src/cli-log.js";
 import { run } from "../../src/cli-run.js";
 import { loadSession } from "../../src/cli-session.js";
 import { Client } from "../../src/client.js";
@@ -85,10 +86,17 @@ const DAY = "2024/2024-03/2024-03-01";
 const TOAST = new TextEncoder().encode("a few seconds of the wedding toast");
 
 // Ente's ML data for beach.jpg: a face it found, and the photo's CLIP
-// embedding.
+// embedding, here that of a photo of a sunset (see clip-keywords.test.ts).
 const ML_DATA = {
     face: { faces: [{ faceID: "100_1", score: 0.98 }] },
-    clip: { embedding: [0.5, 0.6, 0.7] },
+    clip: {
+        embedding: JSON.parse(
+            readFileSync(
+                new URL("../clip-keywords-sunset.json", import.meta.url),
+                "utf-8",
+            ),
+        ).embedding,
+    },
 };
 
 // Each file's ID, its owner, its original as uploaded, and the metadata its
@@ -274,15 +282,17 @@ afterAll(() => {
 
 // Run `quak backup <dir>` as `bin/quak.ts` runs it, sending its requests
 // through `fetch`, and return its exit code and everything it printed on
-// stderr. Its requests are retried as those of `quak backup` are, except that
+// stderr and on stdout. Its requests are retried as those of `quak backup`
-// a retry does not wait. Its cache is beside `dir`, so each run of one
+// are, except that a retry does not wait. A download is given up after
-// directory finds the cache the run before it left, as cron's runs find the
+// `downloadTimeoutMs` with no bytes received, 60 seconds unless given. Its
-// user's.
+// cache is beside `dir`, so each run of one directory finds the cache the run
+// before it left, as cron's runs find the user's.
 const backup = async (
     dir: string,
-    opts: { verify?: boolean } = {},
+    opts: { verify?: boolean; json?: boolean } = {},
     fetch = server,
-): Promise<{ code: number; stderr: string }> => {
+    downloadTimeoutMs?: number,
+): Promise<{ code: number; stderr: string; stdout: string }> => {
     let printed = "";
     const stderr = new Writable({
         write(chunk: Buffer, _encoding, done) {
@@ -290,8 +300,10 @@ const backup = async (
             done();
         },
     });
+    let output = "";
     const stdout = new Writable({
-        write(_chunk, _encoding, done) {
+        write(chunk: Buffer, _encoding, done) {
+            output += chunk.toString();
             done();
         },
     });
@@ -299,24 +311,26 @@ const backup = async (
     const prompted = async (): Promise<never> => {
         throw new Error("quak backup prompted");
     };
+    const log = stderrLog(stderr, "info");
     const ctx: CliContext = {
         stdout,
-        stderr,
+        log,
         sessionDir,
         cacheDir: `${dir}-cache`,
         loadSession: (path) =>
             loadSession(path, {
                 fetch,
                 retry: { ...UNATTENDED_RETRY_OPTIONS, sleep: async () => {} },
+                downloadTimeoutMs,
             }),
         login: prompted,
         prompt: prompted,
         promptSecret: prompted,
     };
     const code = await new Promise<number>((resolve) => {
-        void run(backupCommand(ctx, dir, opts), stdout, stderr, resolve);
+        void run(backupCommand(ctx, dir, opts), stdout, stderr, log, resolve);
     });
-    return { code, stderr: printed };
+    return { code, stderr: printed, stdout: output };
 };
 
 // The ID of the file whose original a request downloads, or undefined for any
@@ -329,6 +343,41 @@ const downloadOf = (input: RequestInfo | URL): number | undefined => {
         : undefined;
 };
 
+// The error Node gives for a connection to `address` that was refused.
+const refusedAt = (address: string): Error =>
+    Object.assign(new Error(`connect ECONNREFUSED ${address}`), {
+        code: "ECONNREFUSED",
+    });
+
+// What Node's `fetch` rejects with when the server refuses the connection, as
+// for every failure below HTTP: a TypeError that says only "fetch failed",
+// with the reason, and its errno, as its cause. When the server has several
+// addresses and each one refuses, the cause is an AggregateError with an empty
+// message, one error per address and the errno of the first. `reason` is the
+// error as quak prints it and records it in `failures.json`.
+const REFUSED = [
+    {
+        addresses: "its one address",
+        error: (): TypeError =>
+            new TypeError("fetch failed", { cause: refusedAt("1.2.3.4:443") }),
+        reason: "fetch failed: connect ECONNREFUSED 1.2.3.4:443",
+    },
+    {
+        addresses: "each of its two addresses",
+        error: (): TypeError =>
+            new TypeError("fetch failed", {
+                cause: Object.assign(
+                    new AggregateError([
+                        refusedAt("2001:db8::1:443"),
+                        refusedAt("1.2.3.4:443"),
+                    ]),
+                    { code: "ECONNREFUSED" },
+                ),
+            }),
+        reason: "fetch failed: connect ECONNREFUSED 2001:db8::1:443, connect ECONNREFUSED 1.2.3.4:443",
+    },
+];
+
 // The fake server, pushing onto `downloads` the ID of each file whose original
 // is downloaded.
 const recordingDownloads =
@@ -369,7 +418,7 @@ describe("the first backup of the account", () => {
         expect(downloads.sort()).toEqual([100, 200, 300]);
     });
 
-    // The tree "Backup layout" in the README describes. Each original is at
+    // The tree under "The backup directory" in the README. Each original is at
     // its save path, `YYYY/YYYY-MM/YYYY-MM-DD/YYYY-MM-DD.<fileID>.<ext>`, with
     // the extension of its title; the live photo is its image and its video,
     // each with the extension it had inside the ZIP, and a `.livephoto.json`
@@ -444,7 +493,10 @@ describe("the first backup of the account", () => {
             },
             updationTime: TAKEN,
         });
-        expect(beach.mlData).toEqual(ML_DATA);
+        // The JSON holds the ML data without its CLIP embedding, and the
+        // keywords the embedding gives in its place.
+        expect(beach.mlData).toEqual({ face: ML_DATA.face });
+        expect(beach.keywords).toEqual(["Sunset"]);
         expect(beach.imageMetadata.exif.Make.description).toBe("Canon");
         expect(beach.imageMetadata.exif.Model.description).toBe("EOS R5");
 
@@ -455,6 +507,7 @@ describe("the first backup of the account", () => {
             metadata: { title: "toast.mp4", fileType: "video" },
         });
         expect(toast).not.toHaveProperty("mlData");
+        expect(toast).not.toHaveProperty("keywords");
         expect(toast).not.toHaveProperty("imageMetadata");
         expect(toast).not.toHaveProperty("imageMetadataError");
 
@@ -592,6 +645,40 @@ describe("quak backup", () => {
         ).toEqual([]);
     });
 
+    // The user has put a file in collections/ with the name of the Trips
+    // folder, so quak cannot make that folder. It says so on one line, writes
+    // the two albums after it, and exits 1, and --json lists the album's ID
+    // in `failedAlbums`. No file failed, so there is no failures.json.
+    it("exits 1 when an album's folder cannot be made, writes the other albums, and lists it in --json", async () => {
+        const dir = mkdtempSync(join(root, "backup-"));
+        mkdirSync(join(dir, "collections"));
+        writeFileSync(join(dir, "collections", "Trips"), "mine");
+
+        const first = await backup(dir);
+        const { code, stdout } = await backup(dir, { json: true });
+
+        expect(first.code).toBe(1);
+        expect(first.stderr).toMatch(/^FAILED album Trips: EEXIST: /m);
+        expect(code).toBe(1);
+        expect(JSON.parse(stdout)).toMatchObject({
+            failed: 0,
+            undecryptableAlbums: [],
+            failedAlbums: [10],
+        });
+        const collections = join(dir, "collections");
+        expect(readJSON(join(collections, "Family.json")).id).toBe(20);
+        expect(readdirSync(join(collections, "Family")).sort()).toEqual([
+            "IMG_0002.heic",
+            "IMG_0002.mov",
+            "beach.jpg",
+        ]);
+        expect(readJSON(join(collections, "Friend's Wedding.json")).id).toBe(
+            30,
+        );
+        expect(existsSync(join(collections, "Trips.json"))).toBe(false);
+        expect(existsSync(join(dir, "failures.json"))).toBe(false);
+    });
+
     // The server no longer accepts the saved session's token, as after
     // `quak logout` elsewhere, and answers every request with 401. The run
     // stops at the refresh it starts with, says to log in again, and exits 3.
@@ -619,6 +706,317 @@ describe("quak backup", () => {
         expect(readdirSync(dir)).toEqual([]);
     });
 
+    // The server refuses every connection, at its one address or at each of
+    // several. quak tries each request again, here without waiting, and then
+    // the run stops at the refresh it starts with. The line it prints gives
+    // the reason Node's `fetch` put on the error's cause, so a cron log tells
+    // a refused connection from a name that did not resolve, and the exit
+    // code is 1.
+    it.each(REFUSED)(
+        "prints why the refresh could not reach the server at $addresses, and exits 1",
+        async ({ error, reason }) => {
+            const dir = mkdtempSync(join(root, "backup-"));
+            const fetch: typeof globalThis.fetch = async () => {
+                throw error();
+            };
+
+            const { code, stderr } = await backup(dir, {}, fetch);
+
+            expect(code).toBe(1);
+            expect(stderr).toBe(
+                "Starting backup...\n" +
+                    "Refreshing library...\n" +
+                    `quak: ${reason}\n`,
+            );
+        },
+    );
+
+    // The files CDN refuses every connection for toast.mp4, at its one
+    // address or at each of several. Once its retries are spent, the file
+    // goes into `failures.json` with the reason, as a transient failure,
+    // since a later run may well reach the CDN, and the lines the backup
+    // prints for it give the same reason. The rest of the account is backed
+    // up, and the exit code is 1.
+    it.each(REFUSED)(
+        "records why a download could not reach the server at $addresses in failures.json, as transient, and exits 1",
+        async ({ error, reason }) => {
+            let attempts = 0;
+            const fetch: typeof globalThis.fetch = async (input, init) => {
+                if (downloadOf(input) === 200) {
+                    attempts++;
+                    throw error();
+                }
+                return server(input, init);
+            };
+            const dir = mkdtempSync(join(root, "backup-"));
+
+            const { code, stderr } = await backup(dir, {}, fetch);
+
+            expect(code).toBe(1);
+            expect(attempts).toBe(UNATTENDED_RETRY_OPTIONS.attempts);
+            const failures = readJSON(join(dir, "failures.json"));
+            expect(Object.keys(failures.files)).toEqual(["200"]);
+            expect(failures.files["200"]).toMatchObject({
+                fileID: 200,
+                title: "toast.mp4",
+                classification: "transient",
+                attempts: 1,
+                error: reason,
+            });
+            expect(stderr).toContain(`FAILED original toast.mp4: ${reason}\n`);
+            expect(stderr).toContain(
+                `[Friend's Wedding] toast.mp4 (id 200): ${reason}\n`,
+            );
+            expect(readFileSync(join(dir, DAY, "2024-03-01.100.jpg"))).toEqual(
+                Buffer.from(JPEG_WITH_EXIF),
+            );
+            expect(existsSync(join(dir, DAY, "2024-03-01.200.mp4"))).toBe(
+                false,
+            );
+        },
+    );
+
+    // The download of toast.mp4 fails as bun's `fetch` reports a failure, in
+    // the binary `make install` builds: a plain `Error` with bun's own code
+    // and message, and no cause. These are what bun gave for a refused
+    // connection, a name that did not resolve and a reset connection. The
+    // file is tried as often as under Node, and goes into `failures.json`
+    // with that message, as a transient failure.
+    it.each([
+        [
+            "ConnectionRefused",
+            "Unable to connect. Is the computer able to access the url?",
+        ],
+        ["FailedToOpenSocket", "Was there a typo in the url or port?"],
+        [
+            "ECONNRESET",
+            "The socket connection was closed unexpectedly. For more information, pass `verbose: true` in the second argument to fetch()",
+        ],
+    ])(
+        "records a download that failed with bun's %s in failures.json, as transient",
+        async (bunCode, message) => {
+            let attempts = 0;
+            const fetch: typeof globalThis.fetch = async (input, init) => {
+                if (downloadOf(input) === 200) {
+                    attempts++;
+                    throw Object.assign(new Error(message), {
+                        code: bunCode,
+                        errno: 0,
+                    });
+                }
+                return server(input, init);
+            };
+            const dir = mkdtempSync(join(root, "backup-"));
+
+            const { code } = await backup(dir, {}, fetch);
+
+            expect(code).toBe(1);
+            expect(attempts).toBe(UNATTENDED_RETRY_OPTIONS.attempts);
+            const failures = readJSON(join(dir, "failures.json"));
+            expect(failures.files["200"]).toMatchObject({
+                classification: "transient",
+                error: message,
+            });
+        },
+    );
+
+    // The download of toast.mp4 stalls: the server sends the headers and then
+    // never a byte of the body. Each attempt is given up after 50 ms, quak's
+    // own deadline for this run, with a `TimeoutError` whose message says
+    // only that the download stalled. The file goes into `failures.json` as a
+    // transient failure, as a request that ran out of time is retried.
+    it("records a stalled download in failures.json, as transient", async () => {
+        let attempts = 0;
+        const fetch: typeof globalThis.fetch = async (input, init) => {
+            if (downloadOf(input) === 200) {
+                attempts++;
+                return new Response(
+                    new ReadableStream<Uint8Array>({
+                        pull: () => new Promise<void>(() => {}),
+                    }),
+                );
+            }
+            return server(input, init);
+        };
+        const dir = mkdtempSync(join(root, "backup-"));
+
+        const { code } = await backup(dir, {}, fetch, 50);
+
+        expect(code).toBe(1);
+        expect(attempts).toBe(UNATTENDED_RETRY_OPTIONS.attempts);
+        const failures = readJSON(join(dir, "failures.json"));
+        expect(failures.files["200"]).toMatchObject({
+            classification: "transient",
+            error: "download stalled: no bytes received for 50 ms",
+        });
+    });
+
+    // The name of Ente's API server does not resolve when quak fetches the ML
+    // data, after every original has been backed up. No file has ML data
+    // cached yet, so each goes into `failures.json` with the reason, as a
+    // transient failure, as a download that could not reach the server does,
+    // and the exit code is 1.
+    it("records why the ML data fetch could not reach the server in failures.json, as transient, and exits 1", async () => {
+        const fetch: typeof globalThis.fetch = async (input, init) => {
+            if (new URL(String(input)).pathname === "/files/data/fetch") {
+                throw new TypeError("fetch failed", {
+                    cause: Object.assign(
+                        new Error("getaddrinfo ENOTFOUND api.ente.io"),
+                        { code: "ENOTFOUND" },
+                    ),
+                });
+            }
+            return server(input, init);
+        };
+        const dir = mkdtempSync(join(root, "backup-"));
+
+        const { code, stderr } = await backup(dir, {}, fetch);
+
+        expect(code).toBe(1);
+        const error =
+            "ML data: fetch failed: getaddrinfo ENOTFOUND api.ente.io";
+        expect(stderr).toContain(`FAILED ${error}\n`);
+        const failures = readJSON(join(dir, "failures.json"));
+        expect(
+            Object.values(failures.files).map((f) => [
+                f.fileID,
+                f.classification,
+                f.error,
+            ]),
+        ).toEqual([
+            [100, "transient", error],
+            [200, "transient", error],
+            [300, "transient", error],
+        ]);
+    });
+
+    // The server sends beach.jpg's ML data encrypted under a key that is not
+    // the file's, so quak cannot decrypt it. The file's JSON has the reason
+    // in place of the ML data, and the file goes into `failures.json` with
+    // it, so the exit code is 1. The other two files have no ML data, which
+    // is no failure.
+    it("records a file whose ML data does not decrypt in its JSON and in failures.json, and exits 1", async () => {
+        const otherKey = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+        const mlData = encryptStreamBlob(
+            gzipSync(JSON.stringify(ML_DATA)),
+            otherKey,
+        );
+        const fetch: typeof globalThis.fetch = async (input, init) => {
+            if (new URL(String(input)).pathname !== "/files/data/fetch") {
+                return server(input, init);
+            }
+            const data = [
+                {
+                    fileID: BEACH.id,
+                    encryptedData: toBase64(mlData.ciphertext),
+                    decryptionHeader: toBase64(mlData.header),
+                },
+            ];
+            return new Response(JSON.stringify({ data }), {
+                headers: { "content-type": "application/json" },
+            });
+        };
+        const dir = mkdtempSync(join(root, "backup-"));
+
+        const { code, stderr } = await backup(dir, {}, fetch);
+
+        expect(code).toBe(1);
+        const reason = "secretstream chunk authentication failed";
+        const beachJSON = readJSON(join(dir, DAY, "2024-03-01.100.json"));
+        expect(beachJSON).not.toHaveProperty("mlData");
+        expect(beachJSON.mlDataError).toBe(reason);
+        const failures = readJSON(join(dir, "failures.json"));
+        expect(Object.keys(failures.files)).toEqual(["100"]);
+        expect(failures.files["100"]).toMatchObject({
+            fileID: 100,
+            title: "beach.jpg",
+            error: `ML data: ${reason}`,
+        });
+        expect(stderr).toContain(`beach.jpg (id 100): ML data: ${reason}\n`);
+        for (const fileID of [200, 300]) {
+            const json = readJSON(join(dir, DAY, `2024-03-01.${fileID}.json`));
+            expect(json).not.toHaveProperty("mlData");
+            expect(json).not.toHaveProperty("mlDataError");
+        }
+    });
+
+    // A program using quak as a library backs the account up, and another ML
+    // data fetch, as one the library's refresh starts, fails while the backup
+    // writes the JSON files. The backup's own fetch got beach.jpg's ML data
+    // under a key that is not the file's; the fetch that fails leaves that
+    // reason in place, so beach.jpg's JSON and `failures.json` still give it.
+    it("keeps the reason in beach.jpg's JSON and in failures.json when an ML data fetch fails while lib.backup() writes the JSON files", async () => {
+        const otherKey = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+        const mlData = encryptStreamBlob(
+            gzipSync(JSON.stringify(ML_DATA)),
+            otherKey,
+        );
+        let mlDataFetchFails = false;
+        const fetch: typeof globalThis.fetch = async (input, init) => {
+            if (new URL(String(input)).pathname !== "/files/data/fetch") {
+                return server(input, init);
+            }
+            if (mlDataFetchFails) throw new Error("the connection was reset");
+            const data = [
+                {
+                    fileID: BEACH.id,
+                    encryptedData: toBase64(mlData.ciphertext),
+                    decryptionHeader: toBase64(mlData.header),
+                },
+            ];
+            return new Response(JSON.stringify({ data }), {
+                headers: { "content-type": "application/json" },
+            });
+        };
+        const dir = mkdtempSync(join(root, "backup-"));
+        const lib = await Library.open({
+            client: loadSession(join(sessionDir, "session.json"), {
+                fetch,
+                retry: { ...UNATTENDED_RETRY_OPTIONS, sleep: async () => {} },
+            })!,
+            cacheDirectory: `${dir}-cache`,
+            downloadDirectory: dir,
+            refreshIntervalSeconds: Infinity,
+            precacheThumbnails: false,
+            precacheOriginals: false,
+        });
+        try {
+            // The backup reads a file's cached ML data just before it writes
+            // that file's JSON. The first time, a refresh starts an ML data
+            // fetch whose request fails, and the backup goes on once that
+            // fetch has failed.
+            const forFile = lib.mldata.forFile.bind(lib.mldata);
+            vi.spyOn(lib.mldata, "forFile").mockImplementationOnce(
+                async (args) => {
+                    mlDataFetchFails = true;
+                    await lib.fresh();
+                    await vi.waitFor(
+                        () => expect(lib.status().lastMLError).toBeDefined(),
+                        { timeout: 2000, interval: 5 },
+                    );
+                    return forFile(args);
+                },
+            );
+
+            const result = await lib.backup();
+
+            expect(result.failed).toBe(1);
+            const reason = "secretstream chunk authentication failed";
+            const beachJSON = readJSON(join(dir, DAY, "2024-03-01.100.json"));
+            expect(beachJSON).not.toHaveProperty("mlData");
+            expect(beachJSON.mlDataError).toBe(reason);
+            const failures = readJSON(join(dir, "failures.json"));
+            expect(Object.keys(failures.files)).toEqual(["100"]);
+            expect(failures.files["100"]).toMatchObject({
+                fileID: 100,
+                title: "beach.jpg",
+                error: `ML data: ${reason}`,
+            });
+        } finally {
+            await lib.close();
+        }
+    });
+
     // Something changed beach.jpg on disk after it was backed up. A run with
     // --verify hashes every stored original, finds that one no longer matches
     // the hash Ente recorded, says so, and downloads it again; it put back the
@@ -719,6 +1117,9 @@ describe("a backup whose lock is lost", () => {
         expect(code).toBe(1);
         expect(stderr).toBe(
             "Starting backup...\n" +
+                "Fetched the files of 1 of 3 collections\n" +
+                "Fetched the files of 2 of 3 collections\n" +
+                "Fetched the files of 3 of 3 collections\n" +
                 "Refreshing library...\n" +
                 "Fetching original beach.jpg (100)...\n" +
                 "Fetching original IMG_0002.HEIC (300)...\n" +

test/cli/backup-undecryptable.test.ts

@@ -42,6 +42,7 @@ import {
     saveSession,
     type CliContext,
 } from "../../src/cli-commands.js";
+import { stderrLog } from "../../src/cli-log.js";
 import { loadSession } from "../../src/cli-session.js";
 import { Client, type ClientSnapshot } from "../../src/client.js";
 import { encryptBlob, init, toBase64 } from "../../src/crypto/index.js";
@@ -304,7 +305,7 @@ const context = (ente: FakeEnte): CliContext => {
     saveSession(join(root, "session"), ente.snapshot());
     return {
         stdout,
-        stderr,
+        log: stderrLog(stderr, "info"),
         sessionDir: join(root, "session"),
         cacheDir: join(root, "cache"),
         loadSession: (path) =>
@@ -370,6 +371,24 @@ describe("quak backup with records it cannot decrypt", () => {
         expect(stderr.text).toContain("  Failed:      2\n");
     });
 
+    // The album is an error line. The last line is fatal and counts the files
+    // and the album, so `-q`, which prints fatal lines only, still says why
+    // the backup exits 1.
+    it("logs the album at error, and ends with one fatal line counting the files and the album", async () => {
+        const ctx = {
+            ...context(brokenAccount()),
+            log: stderrLog(stderr, "error"),
+        };
+        expect(await backupCommand(ctx, backupDir(), {})).toBe(1);
+
+        expect(stderr.text).toMatch(
+            /^FAILED album 2: could not be decrypted: /,
+        );
+        expect(stderr.text.split("\n").at(-2)).toBe(
+            `quak: 2 file(s) and 1 album(s) failed; see ${join(backupDir(), "failures.json")} and the FAILED lines`,
+        );
+    });
+
     it("names each album it cannot decrypt in the --json result", async () => {
         expect(await backup(brokenAccount(), { json: true })).toBe(1);
 
@@ -548,7 +567,7 @@ describe("the read commands with records quak cannot decrypt", () => {
         expect(await collectionsCommand(context(ente), {})).toBe(0);
         expect(stdout.text).toBe("1\talbum\tTrip\n");
 
-        expect(await filesCommand(context(ente), { collection: "1" })).toBe(0);
+        expect(await filesCommand(context(ente), "1", {})).toBe(0);
         expect(stdout.text).toBe("10\timage\tphoto-10.jpg\n");
     });
 });

test/cli/backup.test.ts

@@ -52,6 +52,7 @@ import { tmpdir } from "node:os";
 import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
 
 import { runBackup, type BackupLibrary } from "../../src/backup.js";
+import { DISCOVER_CATEGORIES } from "../../src/clip-keyword-vectors.js";
 import { Library } from "../../src/library/index.js";
 import type { ContentSource } from "../../src/library/content.js";
 import type { CollectionsPage, FilesPage } from "../../src/client.js";
@@ -191,9 +192,12 @@ class HostileClient extends MockClient {
 }
 
 // A content source that writes byte buffers of the expected length and can be
-// told to fail one fileID's original, to exercise per-file resilience.
+// told to fail one fileID's original, as a server error or as a 404, or to
+// write other bytes for it, to exercise per-file resilience.
 interface StubSource extends ContentSource {
     failID?: number;
+    notFoundID?: number;
+    otherBytesID?: number;
     failThumbID?: number;
     originalCalls: number;
 }
@@ -204,8 +208,10 @@ const stubSource = (): StubSource => {
         original: async ({ file: f, destination }) => {
             s.originalCalls++;
             if (s.failID === f.id) throw new Error("HTTP 500 from server");
+            if (s.notFoundID === f.id) throw new Error("HTTP 404 from server");
             const size = SIZE_BY_ID[f.id] ?? 10;
-            writeFileSync(destination, Buffer.alloc(size));
+            const fill = s.otherBytesID === f.id ? 2 : 0;
+            writeFileSync(destination, Buffer.alloc(size, fill));
             return { bytesWritten: size };
         },
         thumbnail: async ({ file: f, destination }) => {
@@ -696,17 +702,26 @@ describe("lib.backup", () => {
         // A child that has already exited: its process ID is not running.
         const exitedPID = spawnSync(process.execPath, ["-e", ""]).pid;
         const leftover = `.quak-backup-2026-03-01.100.jpg-${exitedPID}-abc123.tmp`;
+        // A live photo's image and video downloaded to replace a stored one,
+        // before they were renamed into place.
+        const replacement = [
+            `.quak-${exitedPID}-abc789.heic`,
+            `.quak-${exitedPID}-abc789.mov`,
+        ];
         // This test's own process stands in for a backup running at the same
         // time.
         const inProgress = `.quak-backup-2026-03-01.101.jpg-${process.pid}-def456.tmp`;
-        writeFileSync(join(day, leftover), "partial");
+        for (const name of [leftover, ...replacement, inProgress]) {
-        writeFileSync(join(day, inProgress), "partial");
+            writeFileSync(join(day, name), "partial");
+        }
         const lib = await openLibrary(stubSource());
 
         await lib.backup({ downloadDirectory: outDir });
 
         const names = readdirSync(day);
         expect(names).not.toContain(leftover);
+        expect(names).not.toContain(replacement[0]);
+        expect(names).not.toContain(replacement[1]);
         expect(names).toContain(inProgress);
         lib.close();
     });
@@ -932,19 +947,30 @@ describe("the backup lock", () => {
     });
 });
 
-// Also serves ML data: file 100 has `ML_PAYLOAD`, the other two have none.
+// Also serves ML data: file 100 has `ML_PAYLOAD`, whose CLIP embedding is that
-// While `mlError` is set, every ML data request fails with it.
+// of a photo of a sunset (see clip-keywords.test.ts), and the other two have
-const ML_PAYLOAD = { face: { faces: [] }, clip: { embedding: [0.5, 0.25] } };
+// none. While `mlError` is set, every ML data request fails with it.
+const SUNSET_EMBEDDING: number[] = JSON.parse(
+    readFileSync(
+        new URL("../clip-keywords-sunset.json", import.meta.url),
+        "utf-8",
+    ),
+).embedding;
+const ML_PAYLOAD = {
+    face: { faces: [] },
+    clip: { embedding: SUNSET_EMBEDDING },
+};
 
 class MLClient extends MockClient {
     mlError?: string;
-    async fetchMLData(args: {
+    async fetchMLData(args: { fileIDs: number[] }): Promise<{
-        fileIDs: number[];
+        payloads: Map<number, MLData>;
-    }): Promise<Map<number, MLData>> {
+        errors: Map<number, unknown>;
+    }> {
         if (this.mlError) throw new Error(this.mlError);
-        const result = new Map<number, MLData>();
+        const payloads = new Map<number, MLData>();
-        if (args.fileIDs.includes(100)) result.set(100, ML_PAYLOAD);
+        if (args.fileIDs.includes(100)) payloads.set(100, ML_PAYLOAD);
-        return result;
+        return { payloads, errors: new Map() };
     }
 }
 
@@ -953,16 +979,99 @@ const fileJSON = (outDir: string, fileID: number): Record<string, unknown> =>
     JSON.parse(readFileSync(saved(outDir, `${fileID}.json`), "utf-8"));
 
 describe("ML data in each file's JSON", () => {
-    it("writes a file's ML data, and no ML field for a file that has none", async () => {
+    // The JSON holds the ML data without its CLIP embedding, and in its place
+    // the keywords the embedding gives.
+    it("writes a file's ML data and keywords, and no ML field for a file that has none", async () => {
         const lib = await openLibrary(stubSource(), new MLClient());
         const outDir = join(root, "backup");
 
         const result = await lib.backup({ downloadDirectory: outDir });
 
         expect(result.failed).toBe(0);
-        expect(fileJSON(outDir, 100).mlData).toEqual(ML_PAYLOAD);
+        expect(fileJSON(outDir, 100).mlData).toEqual({ face: { faces: [] } });
+        expect(fileJSON(outDir, 100).keywords).toEqual(["Sunset"]);
         expect(fileJSON(outDir, 101)).not.toHaveProperty("mlData");
         expect(fileJSON(outDir, 101)).not.toHaveProperty("mlDataError");
+        expect(fileJSON(outDir, 101)).not.toHaveProperty("keywords");
+        await lib.close();
+    });
+
+    // A file's ML data can hold faces and no CLIP embedding. Its JSON then has
+    // the ML data and no keywords.
+    it("writes no keywords for ML data without a CLIP embedding", async () => {
+        const faces = { face: { faces: [{ faceID: "101_1", score: 0.9 }] } };
+
+        // Gives file 101 ML data holding only faces.
+        class FacesClient extends MockClient {
+            async fetchMLData(args: { fileIDs: number[] }): Promise<{
+                payloads: Map<number, MLData>;
+                errors: Map<number, unknown>;
+            }> {
+                const payloads = new Map<number, MLData>();
+                if (args.fileIDs.includes(101)) payloads.set(101, faces);
+                return { payloads, errors: new Map() };
+            }
+        }
+        const lib = await openLibrary(stubSource(), new FacesClient());
+        const outDir = join(root, "backup");
+
+        const result = await lib.backup({ downloadDirectory: outDir });
+
+        expect(result.failed).toBe(0);
+        expect(fileJSON(outDir, 101).mlData).toEqual(faces);
+        expect(fileJSON(outDir, 101)).not.toHaveProperty("keywords");
+        await lib.close();
+    });
+
+    // Ente's photos app keeps videos out of some Discover categories, Identity
+    // among them. Here a photo and a video share one CLIP embedding, Identity's
+    // own text embedding, so the photo gets the keyword Identity and the video
+    // does not.
+    it("keeps a video out of a category that leaves out videos", async () => {
+        const identity = DISCOVER_CATEGORIES.find(
+            (c) => c.title === "Identity",
+        )!;
+        expect(identity.showVideo).toBe(false);
+        const toast = file(102, 1, "toast.mp4");
+        const video = {
+            ...toast,
+            metadata: { ...toast.metadata, fileType: "video" as const },
+        };
+
+        // Serves beach.jpg and the video in the Vacation album, and gives
+        // each ML data holding only that embedding.
+        class VideoClient extends MockClient {
+            override async filesSince(args: {
+                collectionID: number;
+            }): Promise<FilesPage> {
+                const files =
+                    args.collectionID === 1
+                        ? [file(100, 1, "beach.jpg"), video]
+                        : [];
+                return { files, deleted: [], cursor: 1 };
+            }
+            async fetchMLData(args: { fileIDs: number[] }): Promise<{
+                payloads: Map<number, MLData>;
+                errors: Map<number, unknown>;
+            }> {
+                const payloads = new Map<number, MLData>();
+                for (const id of args.fileIDs) {
+                    payloads.set(id, {
+                        clip: { embedding: identity.textEmbedding },
+                    });
+                }
+                return { payloads, errors: new Map() };
+            }
+        }
+        const lib = await openLibrary(stubSource(), new VideoClient());
+        const outDir = join(root, "backup");
+
+        const result = await lib.backup({ downloadDirectory: outDir });
+
+        expect(result.failed).toBe(0);
+        expect(fileJSON(outDir, 100).keywords).toContain("Identity");
+        expect(fileJSON(outDir, 102)).toHaveProperty("keywords");
+        expect(fileJSON(outDir, 102).keywords).not.toContain("Identity");
         await lib.close();
     });
 
@@ -978,7 +1087,7 @@ describe("ML data in each file's JSON", () => {
         const result = await lib.backup({ downloadDirectory: outDir });
 
         // File 100's ML data was cached by the first run and is kept.
-        expect(fileJSON(outDir, 100).mlData).toEqual(ML_PAYLOAD);
+        expect(fileJSON(outDir, 100).mlData).toEqual({ face: { faces: [] } });
         expect(fileJSON(outDir, 100)).not.toHaveProperty("mlDataError");
         for (const fileID of [101, 200]) {
             expect(fileJSON(outDir, fileID).mlDataError).toBe(
@@ -1011,7 +1120,7 @@ describe("ML data in each file's JSON", () => {
 
         expect(result.failed).toBe(0);
         expect(result.skipped).toBe(3);
-        expect(fileJSON(outDir, 100).mlData).toEqual(ML_PAYLOAD);
+        expect(fileJSON(outDir, 100).mlData).toEqual({ face: { faces: [] } });
         for (const fileID of [100, 101, 200]) {
             expect(fileJSON(outDir, fileID)).not.toHaveProperty("mlDataError");
         }
@@ -1294,7 +1403,8 @@ describe("image metadata in each file's JSON", () => {
 });
 
 // With `verify`, each original already stored is hashed, and one that does not
-// match the content hash its metadata records is downloaded again.
+// match the content hash its metadata records is downloaded again, and replaced
+// only by a download that matches.
 describe("backup with verify", () => {
     // MockClient's files, each recording the hash of what `stubSource` writes
     // for it, except diagram.png (200), which records none.
@@ -1337,6 +1447,12 @@ describe("backup with verify", () => {
     const good = Buffer.alloc(SIZE_BY_ID[100]!);
     const corrupt = Buffer.alloc(SIZE_BY_ID[100]!, 1);
 
+    // The temporary files left in the date folder of the backup in `outDir`.
+    const tempFiles = (outDir: string): string[] =>
+        readdirSync(join(outDir, DAY)).filter((name) =>
+            name.startsWith(".quak-"),
+        );
+
     it("leaves an original that matches its hash, and one with no hash, as they are", async () => {
         const { lib, source, outDir } = await backedUp();
         const calls = source.originalCalls;
@@ -1381,13 +1497,16 @@ describe("backup with verify", () => {
         expect(log.filter((msg) => msg.startsWith("MISMATCH"))).toEqual([
             "MISMATCH original beach.jpg (100): its bytes do not match its content hash",
         ]);
+        expect(tempFiles(outDir)).toEqual([]);
         await lib.close();
     });
 
-    it("records a failed download in failures.json, with the original removed", async () => {
+    // A copy whose hash does not match is still mostly the photo, so the
+    // backup keeps it until it holds a better one.
+    it("keeps an original that does not match its hash when its download answers 404", async () => {
         const { lib, source, outDir } = await backedUp();
         writeFileSync(saved(outDir, "100.jpg"), corrupt);
-        source.failID = 100;
+        source.notFoundID = 100;
 
         const result = await lib.backup({
             downloadDirectory: outDir,
@@ -1400,18 +1519,18 @@ describe("backup with verify", () => {
             failed: 1,
         });
         expect(Object.keys(readLedger(outDir).files)).toEqual(["100"]);
-        expect(existsSync(saved(outDir, "100.jpg"))).toBe(false);
+        expect(readFileSync(saved(outDir, "100.jpg"))).toEqual(corrupt);
+        expect(
+            readlinkSync(join(outDir, "collections", "Vacation", "beach.jpg")),
+        ).toBe(linkTo("100.jpg"));
+        expect(tempFiles(outDir)).toEqual([]);
         await lib.close();
     });
 
-    it("records in failures.json an original the cache puts back with the same bad bytes", async () => {
+    it("keeps an original that does not match its hash when its download does not match either", async () => {
-        const lib = await openLibrary(stubSource(), new HashedClient());
+        const { lib, source, outDir } = await backedUp();
-        const outDir = join(root, "backup");
+        writeFileSync(saved(outDir, "100.jpg"), corrupt);
-        // The cache holds a bad copy, and a backup copies an original the
+        source.otherBytesID = 100;
-        // cache holds to its save path.
-        const cached = await lib.photos.byID({ fileID: 100 })!.original();
-        writeFileSync(cached.path, corrupt);
-        await lib.backup({ downloadDirectory: outDir });
 
         const result = await lib.backup({
             downloadDirectory: outDir,
@@ -1424,10 +1543,39 @@ describe("backup with verify", () => {
             failed: 1,
         });
         expect(result.errors.map((e) => e.error)).toEqual([
-            "the original put back does not match its content hash either",
+            "the downloaded original does not match its content hash either",
         ]);
         expect(Object.keys(readLedger(outDir).files)).toEqual(["100"]);
         expect(readFileSync(saved(outDir, "100.jpg"))).toEqual(corrupt);
+        expect(tempFiles(outDir)).toEqual([]);
+        await lib.close();
+    });
+
+    // The cache can hold the same bad bytes, as a copy from it is not checked
+    // as a download is, so the replacement is always downloaded.
+    it("downloads the replacement even when the cache holds the original", async () => {
+        const source = stubSource();
+        const lib = await openLibrary(source, new HashedClient());
+        const outDir = join(root, "backup");
+        // The cache holds a bad copy, and a backup copies an original the
+        // cache holds to its save path.
+        const cached = await lib.photos.byID({ fileID: 100 })!.original();
+        writeFileSync(cached.path, corrupt);
+        await lib.backup({ downloadDirectory: outDir });
+        const calls = source.originalCalls;
+
+        const result = await lib.backup({
+            downloadDirectory: outDir,
+            verify: true,
+        });
+
+        expect(result).toMatchObject({
+            downloaded: 1,
+            mismatched: 1,
+            failed: 0,
+        });
+        expect(source.originalCalls).toBe(calls + 1);
+        expect(readFileSync(saved(outDir, "100.jpg"))).toEqual(good);
         await lib.close();
     });
 
@@ -1498,23 +1646,29 @@ describe("backup album folders", () => {
         files: EnteFile[];
     }
 
-    const libraryOf = (albums: Album[]): BackupLibrary => ({
+    // The original of the file `notFound`, if given, always fails to download.
+    const libraryOf = (albums: Album[], notFound?: number): BackupLibrary => ({
         refresh: async () => {},
         listCollections: () => albums.map((a) => a.collection),
         listFiles: (id) =>
             albums.find((a) => a.collection.id === id)?.files ?? [],
         undecryptable: () => [],
         original: async (fileID) => {
+            if (fileID === notFound) throw new Error("HTTP 404");
             const path = join(root, `source-${fileID}`);
             writeFileSync(path, `original ${fileID}`);
             return { path };
         },
+        fetchOriginal: async () => {
+            throw new Error("no verify in this stand-in");
+        },
         thumbnail: async () => {
             throw new Error("no thumbnails in this stand-in");
         },
         contentConcurrency: 5,
         fetchMLData: async () => {},
         mlData: async () => undefined,
+        mlDataError: () => undefined,
         whoami: () => ({ email: "backup@example.com", userID: USER_ID }),
     });
 
@@ -1600,6 +1754,251 @@ describe("backup album folders", () => {
         expect(albumID(outDir, "Trip (11) (12).json")).toBe(12);
     });
 
+    // The next three tests end with the album "ok" (14), whose one file
+    // always fails to download, so each run has a failure to record in
+    // failures.json after the album folders are written.
+    const ok: Album = {
+        collection: collection(14, "ok"),
+        files: [file(5, 14, "e.jpg")],
+    };
+
+    // The folder of an album named "x.json" would be the JSON file of the
+    // album "x", and once ended every run there. Two runs, as on two nights,
+    // write the same tree, and the failed file's attempt count goes up.
+    it("adds the ID to an album whose folder would have another album's JSON name", async () => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf(
+            [
+                {
+                    collection: collection(10, "x"),
+                    files: [file(1, 10, "a.jpg")],
+                },
+                {
+                    collection: collection(11, "x.json"),
+                    files: [file(2, 11, "b.jpg")],
+                },
+                {
+                    collection: collection(12, "Trip"),
+                    files: [file(3, 12, "c.jpg")],
+                },
+                {
+                    collection: collection(13, "TRIP.json"),
+                    files: [file(4, 13, "d.jpg")],
+                },
+                ok,
+            ],
+            5,
+        );
+
+        await runBackup(lib, { downloadDirectory: outDir });
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        expect(result.failedAlbums).toEqual([]);
+        expect(tree(outDir)).toEqual([
+            "TRIP.json (13)/",
+            `TRIP.json (13)/d.jpg -> ${linkTo("4.jpg")}`,
+            "TRIP.json (13).json",
+            "Trip/",
+            `Trip/c.jpg -> ${linkTo("3.jpg")}`,
+            "Trip.json",
+            "ok/",
+            "ok.json",
+            "x/",
+            `x/a.jpg -> ${linkTo("1.jpg")}`,
+            "x.json",
+            "x.json (11)/",
+            `x.json (11)/b.jpg -> ${linkTo("2.jpg")}`,
+            "x.json (11).json",
+        ]);
+        expect(albumID(outDir, "x.json")).toBe(10);
+        expect(albumID(outDir, "x.json (11).json")).toBe(11);
+        expect(albumID(outDir, "TRIP.json (13).json")).toBe(13);
+        expect(albumID(outDir, "ok.json")).toBe(14);
+        expect(result.failed).toBe(1);
+        expect(readLedger(outDir).files["5"]).toMatchObject({ attempts: 2 });
+    });
+
+    // A name over 255 bytes is refused as a file name, and an album folder's
+    // name leaves room for `.json` in its JSON's. "é" takes two bytes, and a
+    // name is cut between two characters.
+    it("cuts an album name and a title too long for a file name short and adds the ID", async () => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf(
+            [
+                {
+                    collection: collection(10, "L".repeat(300)),
+                    files: [file(1, 10, `${"é".repeat(150)}.jpg`)],
+                },
+                ok,
+            ],
+            5,
+        );
+
+        await runBackup(lib, { downloadDirectory: outDir });
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        const folder = `${"L".repeat(245)} (10)`;
+        const link = `${"é".repeat(123)} (1).jpg`;
+        expect(Buffer.byteLength(`${folder}.json`)).toBe(255);
+        expect(Buffer.byteLength(link)).toBe(254);
+        expect(result.failedAlbums).toEqual([]);
+        expect(tree(outDir)).toEqual([
+            `${folder}/`,
+            `${folder}/${link} -> ${linkTo("1.jpg")}`,
+            `${folder}.json`,
+            "ok/",
+            "ok.json",
+        ]);
+        expect(albumID(outDir, `${folder}.json`)).toBe(10);
+        expect(albumID(outDir, "ok.json")).toBe(14);
+        expect(result.failed).toBe(1);
+        expect(readLedger(outDir).files["5"]).toMatchObject({ attempts: 2 });
+    });
+
+    // The user has put a file in collections/ with the name of the album
+    // Trip's folder, so the folder cannot be made.
+    it("goes on to the next album when an album's folder cannot be made, and lists it as failed", async () => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf(
+            [
+                {
+                    collection: collection(10, "Trip"),
+                    files: [file(1, 10, "a.jpg")],
+                },
+                ok,
+            ],
+            5,
+        );
+        mkdirSync(join(outDir, "collections"), { recursive: true });
+        writeFileSync(join(outDir, "collections", "Trip"), "mine");
+        const logged: string[] = [];
+
+        const result = await runBackup(lib, {
+            downloadDirectory: outDir,
+            onProgress: (message) => logged.push(message),
+        });
+
+        expect(result.failedAlbums).toEqual([10]);
+        expect(logged).toContainEqual(
+            expect.stringMatching(/^FAILED album Trip: EEXIST: /),
+        );
+        expect(tree(outDir)).toEqual(["Trip", "ok/", "ok.json"]);
+        expect(albumID(outDir, "ok.json")).toBe(14);
+        expect(existsSync(saved(outDir, "1.jpg"))).toBe(true);
+        expect(result.failed).toBe(1);
+        expect(readLedger(outDir).files["5"]).toMatchObject({ attempts: 1 });
+    });
+
+    // The extensions of these titles leave no room for the ID and the "a"
+    // before them, so each is cut short to 250 bytes, which leaves one, for
+    // the "a". File 1's extension is 303 bytes and file 2's 271. Neither
+    // extension is only letters and digits, so both originals are saved with
+    // `.bin`, a name that fits.
+    it("cuts the extension of a title short when it leaves no room for the ID", async () => {
+        const outDir = join(root, "backup");
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [
+                    file(1, 10, `a.${"L".repeat(300)}-x`),
+                    file(2, 10, `a.${"€".repeat(90)}`),
+                ],
+            },
+        ]);
+
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        const link = `a (1).${"L".repeat(249)}`;
+        const link2 = `a (2).${"€".repeat(83)}`;
+        expect(Buffer.byteLength(link)).toBe(255);
+        expect(Buffer.byteLength(link2)).toBe(255);
+        expect(result.failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Trip/",
+            `Trip/${link} -> ${linkTo("1.bin")}`,
+            `Trip/${link2} -> ${linkTo("2.bin")}`,
+            "Trip.json",
+        ]);
+    });
+
+    // Files 1 and 3 share a title, so each gets its ID before the
+    // extension. File 2's title is too long, and its extension leaves no
+    // room for the ID and the "x" before it. Were the ID put at the end of
+    // file 2's title cut short, its link would have file 1's name, and the
+    // link made second would replace the first.
+    it("keeps names unique when a title's extension leaves no room for the ID", async () => {
+        const outDir = join(root, "backup");
+        const shared = `x.${"Q".repeat(245)} (2)`;
+        const lib = libraryOf([
+            {
+                collection: collection(10, "Trip"),
+                files: [
+                    file(1, 10, shared),
+                    file(2, 10, `x (1).${"Q".repeat(250)}-`),
+                    file(3, 10, shared),
+                ],
+            },
+        ]);
+
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        expect(result.failed).toBe(0);
+        expect(tree(outDir)).toEqual([
+            "Trip/",
+            `Trip/x (1).${"Q".repeat(245)} (2) -> ${linkTo("1.bin")}`,
+            `Trip/x (2).${"Q".repeat(249)} -> ${linkTo("2.bin")}`,
+            `Trip/x (3).${"Q".repeat(245)} (2) -> ${linkTo("3.bin")}`,
+            "Trip.json",
+        ]);
+    });
+
+    // A title of 255 bytes is the longest file name allowed, and an album
+    // name of 250 bytes the longest whose JSON name fits; both are kept as
+    // they are. A name one byte longer gets the ID and is cut short. "é"
+    // takes two bytes, and in both names the room left ends inside one, so
+    // the cut falls before it, one byte short of the room.
+    it("keeps a name at the byte limit and adds the ID to one a byte over it", async () => {
+        const outDir = join(root, "backup");
+        const album = "A".repeat(250);
+        const title = `${"t".repeat(251)}.jpg`;
+        const longAlbum = `${"é".repeat(125)}B`;
+        const longTitle = `${"é".repeat(126)}.jpg`;
+        const lib = libraryOf([
+            {
+                collection: collection(10, album),
+                files: [file(1, 10, title), file(2, 10, longTitle)],
+            },
+            {
+                collection: collection(11, longAlbum),
+                files: [file(3, 11, "c.jpg")],
+            },
+        ]);
+
+        const result = await runBackup(lib, { downloadDirectory: outDir });
+
+        const folder = `${"é".repeat(122)} (11)`;
+        const link = `${"é".repeat(123)} (2).jpg`;
+        expect(Buffer.byteLength(`${album}.json`)).toBe(255);
+        expect(Buffer.byteLength(title)).toBe(255);
+        expect(Buffer.byteLength(longAlbum)).toBe(251);
+        expect(Buffer.byteLength(longTitle)).toBe(256);
+        expect(Buffer.byteLength(`${folder}.json`)).toBe(254);
+        expect(Buffer.byteLength(link)).toBe(254);
+        expect(result.failed).toBe(0);
+        expect(result.failedAlbums).toEqual([]);
+        expect(tree(outDir)).toEqual([
+            `${album}/`,
+            `${album}/${title} -> ${linkTo("1.jpg")}`,
+            `${album}/${link} -> ${linkTo("2.jpg")}`,
+            `${album}.json`,
+            `${folder}/`,
+            `${folder}/c.jpg -> ${linkTo("3.jpg")}`,
+            `${folder}.json`,
+        ]);
+        expect(albumID(outDir, `${album}.json`)).toBe(10);
+        expect(albumID(outDir, `${folder}.json`)).toBe(11);
+    });
+
     it("changes nothing on a second run over an unchanged account", async () => {
         const outDir = join(root, "backup");
         const lib = libraryOf([
@@ -1996,11 +2395,12 @@ describe("backup of live photos", () => {
             Buffer.from(IMAGE),
         );
         expect(readFileSync(video)).toEqual(Buffer.from(VIDEO));
+        expect(readdirSync(join(outDir, DAY)).sort()).toEqual(stored);
         expect(tree(outDir)).toEqual(linked);
         await lib.close();
     });
 
-    it("removes both files of a live photo that does not match its hash when downloading it again fails", async () => {
+    it("keeps both files of a live photo that does not match its hash when downloading it again fails", async () => {
         const { file: live, body } = await asLivePhoto(
             file(500, 10, "IMG_0500.HEIC"),
         );
@@ -2018,8 +2418,14 @@ describe("backup of live photos", () => {
 
         expect(result).toMatchObject({ mismatched: 1, failed: 1 });
         expect(Object.keys(readLedger(outDir).files)).toEqual(["500"]);
-        expect(existsSync(saved(outDir, "500.heic"))).toBe(false);
+        expect(readFileSync(saved(outDir, "500.heic"))).toEqual(
-        expect(existsSync(saved(outDir, "500.mov"))).toBe(false);
+            Buffer.from(IMAGE),
+        );
+        expect(readFileSync(saved(outDir, "500.mov"), "utf-8")).toBe(
+            "another few seconds of video",
+        );
+        expect(readdirSync(join(outDir, DAY)).sort()).toEqual(stored);
+        expect(tree(outDir)).toEqual(linked);
         await lib.close();
     });
 

test/cli/bin.test.ts

@@ -1,6 +1,8 @@
 /**
- * Tests for the retry options `bin/quak.ts` loads the saved session with:
+ * Tests for the retry options `bin/quak.ts` loads the saved session with
- * `quak backup` gets the unattended ones, every other command the default.
+ * (`quak backup` gets the unattended ones, every other command the default),
+ * each with the callbacks that log its requests and retries, and for
+ * `quak files` taking its collection ID as an optional argument.
  *
  * Each test runs `bin/quak.ts`, as the smoke test does, with its session loader
  * replaced by one that records the options it is given and reports no session,
@@ -26,14 +28,19 @@ vi.mock("../../src/cli-session.js", () => ({
 const argv = process.argv;
 const dir = mkdtempSync(join(tmpdir(), "quak-bin-test-"));
 
-// Run `quak <args>` to completion. The "Not logged in" message and the exit
+// Run `quak <args>` to completion and return what it wrote on stderr, which is
-// are swallowed.
+// kept off the terminal. The exit is swallowed.
-const quak = async (...args: string[]): Promise<void> => {
+const quak = async (...args: string[]): Promise<string> => {
-    vi.spyOn(process.stderr, "write").mockImplementation(() => true);
+    let written = "";
+    vi.spyOn(process.stderr, "write").mockImplementation((text) => {
+        written += String(text);
+        return true;
+    });
     vi.spyOn(process, "exit").mockImplementation(() => undefined as never);
     process.argv = ["node", "quak", ...args];
     vi.resetModules();
     await import("../../bin/quak.js");
+    return written;
 };
 
 afterEach(() => {
@@ -59,13 +66,32 @@ describe("bin/quak.ts session loading", () => {
                     attempts,
                     baseDelayMs,
                     maxDelayMs,
+                    onRetry: expect.any(Function),
                 }),
+                onRequest: expect.any(Function),
             },
         ]);
     });
 
-    it("loads the session for another command with the default options", async () => {
+    it("loads the session for another command with the default retry options", async () => {
         await quak("collections");
-        expect(loaded).toEqual([undefined]);
+        expect(loaded).toEqual([
+            {
+                retry: { onRetry: expect.any(Function) },
+                onRequest: expect.any(Function),
+            },
+        ]);
+    });
+});
+
+// The command line takes `files` with or without a collection ID, and the
+// command runs as far as its session check either way (issue #211).
+describe("bin/quak.ts files", () => {
+    it("runs without a collection ID", async () => {
+        expect(await quak("files")).toMatch(/^Not logged in/);
+    });
+
+    it("runs with a collection ID", async () => {
+        expect(await quak("files", "7")).toMatch(/^Not logged in/);
     });
 });

test/cli/commands.test.ts

@@ -21,7 +21,7 @@ import {
     utimesSync,
     writeFileSync,
 } from "node:fs";
-import { join } from "node:path";
+import { basename, join } from "node:path";
 import { tmpdir } from "node:os";
 import { PassThrough } from "node:stream";
 import * as jpegJs from "jpeg-js";
@@ -51,13 +51,24 @@ import {
     listMissingThumbnailsCommand,
     fixMissingThumbnailsCommand,
 } from "../../src/cli-commands.js";
+import { stderrLog } from "../../src/cli-log.js";
 import { run } from "../../src/cli-run.js";
 import { loadSession } from "../../src/cli-session.js";
-import type { Client, ClientSnapshot, LoginOptions } from "../../src/client.js";
+import {
+    Client,
+    type ClientSnapshot,
+    type LoginOptions,
+} from "../../src/client.js";
 import { savePath, type ContentSource } from "../../src/library/content.js";
 import type { Collection, EnteFile } from "../../src/model/types.js";
 import { encryptBlob, init, toBase64 } from "../../src/crypto/index.js";
 import { defaultCacheDirectory } from "../../src/library/index.js";
+import {
+    buildAccount,
+    buildMetaFetch,
+    encryptSecretbox,
+    encryptStreamBlob,
+} from "../ente-server.js";
 import { HEIC_WITH_EXIF } from "../exif-heic.js";
 import {
     asLivePhoto,
@@ -111,25 +122,31 @@ const FILES: Record<number, EnteFile[]> = {
 // An original is 7 bytes and a thumbnail 3. `failID` makes that file's
 // original fail; `emptyThumbID` makes the server report that file's
 // thumbnail as empty. `withNewFile` adds new.jpg (102) to Vacation, advancing
-// the collection's updationTime as the server does, and `refreshError` makes
+// the collection's updationTime as the server does. `beachInWork` adds
-// listing collections fail with that message.
+// beach.jpg (100) to Work as well, so that one file is in both albums.
+// `refreshError` makes listing collections fail with that message.
 const fakeClient = (
     opts: {
         failID?: number;
         emptyThumbID?: number;
         withNewFile?: boolean;
+        beachInWork?: boolean;
         refreshError?: string;
     } = {},
 ) => {
     const collections = opts.withNewFile
         ? [{ ...COLLECTIONS[0], updationTime: 2 }, COLLECTIONS[1]]
         : COLLECTIONS;
-    const files = opts.withNewFile
+    let files = FILES;
-        ? {
+    if (opts.withNewFile) {
-              ...FILES,
+        files = {
-              1: [...FILES[1], { ...file(102, 1, "new.jpg"), updationTime: 2 }],
+            ...files,
-          }
+            1: [...files[1], { ...file(102, 1, "new.jpg"), updationTime: 2 }],
-        : FILES;
+        };
+    }
+    if (opts.beachInWork) {
+        files = { ...files, 2: [...files[2], file(100, 2, "beach.jpg")] };
+    }
     const source: ContentSource = {
         original: async ({ file: f, destination }) => {
             if (f.id === opts.failID) throw new Error("HTTP 500 from server");
@@ -171,6 +188,12 @@ const fakeClient = (
     return fake as unknown as Client;
 };
 
+// What a read command prints on stderr while the refresh it waits for fetches
+// the files of each of the fake's two albums, on an empty cache.
+const FETCHED_BOTH_ALBUMS =
+    "Fetched the files of 1 of 2 collections\n" +
+    "Fetched the files of 2 of 2 collections\n";
+
 // Collects everything written to it.
 class Output {
     text = "";
@@ -183,9 +206,11 @@ let root: string;
 let stdout: Output;
 let stderr: Output;
 
+// The commands log at the default level, info, as `quak` without `-v` or `-q`
+// does; the levels have their own tests, in `log.test.ts`.
 const context = (client: Client | null = fakeClient()): CliContext => ({
     stdout,
-    stderr,
+    log: stderrLog(stderr, "info"),
     sessionDir: join(root, "session"),
     cacheDir: join(root, "cache"),
     loadSession: () => client,
@@ -238,7 +263,7 @@ describe("session file", () => {
         const dir = join(root, "backup");
         expect(await whoamiCommand(ctx)).toBe(3);
         expect(await collectionsCommand(ctx, {})).toBe(3);
-        expect(await filesCommand(ctx, { collection: "1" })).toBe(3);
+        expect(await filesCommand(ctx, "1", {})).toBe(3);
         expect(await getCommand(ctx, "100", {})).toBe(3);
         expect(await getThumbCommand(ctx, "100", {})).toBe(3);
         expect(await backupMetadataCommand(ctx, dir, {})).toBe(3);
@@ -485,17 +510,14 @@ describe("collections", () => {
 
 describe("files", () => {
     it("prints one tab-separated line per file", async () => {
-        expect(await filesCommand(context(), { collection: "1" })).toBe(0);
+        expect(await filesCommand(context(), "1", {})).toBe(0);
         expect(stdout.text).toBe(
             "100\timage\tbeach.jpg\n" + "101\timage\tsunset.jpg\n",
         );
     });
 
     it("prints a JSON array with --json", async () => {
-        const code = await filesCommand(context(), {
+        const code = await filesCommand(context(), "2", { json: true });
-            collection: "2",
-            json: true,
-        });
         expect(code).toBe(0);
         expect(JSON.parse(stdout.text)).toEqual([
             {
@@ -509,9 +531,41 @@ describe("files", () => {
     });
 
     it("exits 1 for an unknown collection", async () => {
-        expect(await filesCommand(context(), { collection: "9" })).toBe(1);
+        expect(await filesCommand(context(), "9", {})).toBe(1);
         expect(stderr.text).toBe("Collection 9 not found\n");
     });
+
+    // Without a collection ID it lists every file in the account once (issue
+    // #211). beach.jpg is in Vacation and Work, and Vacation comes first, so it
+    // is listed once, as Vacation's.
+    it("without a collection ID prints every file once", async () => {
+        const ctx = context(fakeClient({ beachInWork: true }));
+        expect(await filesCommand(ctx, undefined, {})).toBe(0);
+        expect(stdout.text).toBe(
+            "100\timage\tbeach.jpg\n" +
+                "101\timage\tsunset.jpg\n" +
+                "200\timage\tdiagram.png\n",
+        );
+        expect(stderr.text).toBe(FETCHED_BOTH_ALBUMS);
+    });
+
+    it("without a collection ID gives each file the first album holding it with --json", async () => {
+        const ctx = context(fakeClient({ beachInWork: true }));
+        expect(await filesCommand(ctx, undefined, { json: true })).toBe(0);
+        expect(
+            JSON.parse(stdout.text).map(
+                (row: { id: number; collectionID: number }) => [
+                    row.id,
+                    row.collectionID,
+                ],
+            ),
+        ).toEqual([
+            [100, 1],
+            [101, 1],
+            [200, 2],
+        ]);
+        expect(stderr.text).toBe(FETCHED_BOTH_ALBUMS);
+    });
 });
 
 describe("get and get-thumb", () => {
@@ -544,14 +598,109 @@ describe("get and get-thumb", () => {
     });
 });
 
+// A file system refuses a file name over 255 bytes. The account here is one
+// album, whose name is 300 bytes, holding one file, 700, with the title given.
+describe("names from an album name or a title over 255 bytes", () => {
+    const longNames = (title: string): Client =>
+        ({
+            ...fakeClient(),
+            collectionsSince: async () => ({
+                collections: [collection(7, "A".repeat(300))],
+                deleted: [],
+                cursor: 1,
+            }),
+            filesSince: async () => ({
+                files: [file(700, 7, title)],
+                deleted: [],
+                cursor: 1,
+            }),
+        }) as unknown as Client;
+    const longTitle = `${"t".repeat(296)}.jpg`;
+
+    // Run `command` in a new directory, where `get` and `get-thumb` without
+    // `--out` write, and return its exit code and the directory.
+    const inNewDirectory = async (
+        command: () => Promise<number>,
+    ): Promise<{ code: number; dir: string }> => {
+        const dir = mkdtempSync(join(root, "cwd-"));
+        const previous = process.cwd();
+        process.chdir(dir);
+        try {
+            return { code: await command(), dir };
+        } finally {
+            process.chdir(previous);
+        }
+    };
+
+    it("get cuts the title short to 255 bytes, keeping its extension, and exits 0", async () => {
+        const { code, dir } = await inNewDirectory(() =>
+            getCommand(context(longNames(longTitle)), "700", {}),
+        );
+
+        const name = `${"t".repeat(251)}.jpg`;
+        expect(Buffer.byteLength(name)).toBe(255);
+        expect(code).toBe(0);
+        expect(readdirSync(dir)).toEqual([name]);
+        expect(stderr.text).toBe(`7 bytes -> ${name}\n`);
+    });
+
+    it("get-thumb cuts the title short so that thumb_ and it fit in 255 bytes, and exits 0", async () => {
+        const { code, dir } = await inNewDirectory(() =>
+            getThumbCommand(context(longNames(longTitle)), "700", {}),
+        );
+
+        const name = `thumb_${"t".repeat(245)}.jpg`;
+        expect(Buffer.byteLength(name)).toBe(255);
+        expect(code).toBe(0);
+        expect(readdirSync(dir)).toEqual([name]);
+        expect(stderr.text).toBe(`3 bytes -> ${name}\n`);
+    });
+
+    it("backup-metadata cuts the album name short so that its folder's name fits in 255 bytes, and exits 0", async () => {
+        const dir = join(root, "dump");
+
+        const code = await backupMetadataCommand(
+            context(longNames("beach.jpg")),
+            dir,
+            {},
+        );
+
+        const folder = `7-${"A".repeat(253)}`;
+        expect(Buffer.byteLength(folder)).toBe(255);
+        expect(code).toBe(0);
+        expect(readdirSync(join(dir, "collections"))).toEqual([folder]);
+        expect(readdirSync(join(dir, "collections", folder)).sort()).toEqual([
+            "700.json",
+            "_collection.json",
+        ]);
+    });
+
+    // The title's extension is 300 letters, too long for the save path's
+    // name, so the original is saved with `.bin`.
+    it("backup saves a title with a 300-letter extension as .bin, and exits 0", async () => {
+        const dir = join(root, "backup");
+        const title = `b.${"e".repeat(300)}`;
+
+        const code = await backupCommand(context(longNames(title)), dir, {});
+
+        const path = savePath(dir, file(700, 7, title));
+        expect(code).toBe(0);
+        expect(basename(path)).toMatch(/^\d{4}-\d{2}-\d{2}\.700\.bin$/);
+        expect(readFileSync(path)).toEqual(Buffer.alloc(7, 700 & 0xff));
+    });
+});
+
 // A live photo, which Ente stores as one ZIP, is written as its image and its
 // video, which a photo viewer can open. The account here is Vacation holding
 // one live photo, 300, downloaded through the real download layer
 // (test/live-photo.ts).
 describe("a live photo", () => {
-    const livePhotoClient = async (image = IMAGE): Promise<Client> => {
+    const livePhotoClient = async (
+        image = IMAGE,
+        title = "IMG_0300.HEIC",
+    ): Promise<Client> => {
         const { file: live, body } = await asLivePhoto(
-            file(300, 1, "IMG_0300.HEIC"),
+            file(300, 1, title),
             livePhotoZip({ "image.heic": image, "video.mov": VIDEO }),
             livePhotoHash(image, VIDEO),
         );
@@ -598,6 +747,44 @@ describe("a live photo", () => {
         );
     });
 
+    // Run `get` without `--out` in a new directory for a live photo titled
+    // `title`, and return its exit code and the names it wrote.
+    const getInNewDirectory = async (
+        title: string,
+    ): Promise<{ code: number; names: string[] }> => {
+        const ctx = context(await livePhotoClient(IMAGE, title));
+        const dir = mkdtempSync(join(root, "cwd-"));
+        const previous = process.cwd();
+        process.chdir(dir);
+        try {
+            const code = await getCommand(ctx, "300", {});
+            return { code, names: readdirSync(dir).sort() };
+        } finally {
+            process.chdir(previous);
+        }
+    };
+    const imageName = `${"t".repeat(250)}.heic`;
+    const videoName = `${"t".repeat(251)}.mov`;
+
+    // The title fits, but ".heic" is one byte longer than ".jpg", so the
+    // image's name is cut short once its extension is in it.
+    it("get cuts its image's name short for a 255-byte title ending in .jpg, and exits 0", async () => {
+        const title = `${"t".repeat(251)}.jpg`;
+
+        const result = await getInNewDirectory(title);
+
+        expect(Buffer.byteLength(title)).toBe(255);
+        expect(Buffer.byteLength(imageName)).toBe(255);
+        expect(Buffer.byteLength(videoName)).toBe(255);
+        expect(result).toEqual({ code: 0, names: [imageName, videoName] });
+    });
+
+    it("get cuts the names of its image and video short for a 300-byte title with no extension, and exits 0", async () => {
+        const result = await getInNewDirectory("t".repeat(300));
+
+        expect(result).toEqual({ code: 0, names: [imageName, videoName] });
+    });
+
     it("get --out writes the image there and the video beside it", async () => {
         const out = join(root, "photo.jpg");
         const video = join(root, "photo.mov");
@@ -718,6 +905,40 @@ describe("backup", () => {
         );
     });
 
+    // A failed file is an error line both where the backup fails it and in
+    // the list at the end. The last line is fatal, so `-q`, which prints
+    // fatal lines only, still says why the backup exits 1.
+    it("logs a failed file at error, and ends with one fatal line counting the failures", async () => {
+        const dir = join(root, "backup");
+        const last = `quak: 1 file(s) and 0 album(s) failed; see ${join(dir, "failures.json")} and the FAILED lines\n`;
+        const ctx = context(fakeClient({ failID: 101 }));
+        expect(
+            await backupCommand(
+                { ...ctx, log: stderrLog(stderr, "error") },
+                dir,
+                {},
+            ),
+        ).toBe(1);
+        expect(stderr.text).toBe(
+            "FAILED original sunset.jpg: HTTP 500 from server\n" +
+                "\nFailed files:\n" +
+                "  [Vacation] sunset.jpg (id 101): HTTP 500 from server\n" +
+                last,
+        );
+
+        stderr.text = "";
+        expect(
+            await backupCommand(
+                { ...ctx, log: stderrLog(stderr, "fatal") },
+                dir,
+                { json: true },
+            ),
+        ).toBe(1);
+        expect(stderr.text).toBe(last);
+    });
+
+    // `--json` shapes stdout only: the log lines stay on stderr, and the JSON
+    // takes the place of the summary.
     it("prints the result as JSON with --json, still exiting 1 on a failure", async () => {
         const ctx = context(fakeClient({ failID: 101 }));
         const code = await backupCommand(ctx, join(root, "backup"), {
@@ -732,7 +953,31 @@ describe("backup", () => {
             failed: 1,
         });
         expect(result.errors[0].fileID).toBe(101);
-        expect(stderr.text).toBe("Starting backup...\n");
+        expect(stderr.text).toContain(
+            "Fetching original sunset.jpg (101)...\n",
+        );
+        expect(stderr.text).not.toContain("Backup complete");
+    });
+
+    // On an empty cache the library's first refresh fetches the files of
+    // every album before the backup can start, which on a large account takes
+    // a while; each album it has fetched the files of is counted on stderr,
+    // with `--json` too.
+    it("counts on stderr each album whose files its first refresh fetched, with --json too", async () => {
+        const start =
+            "Starting backup...\n" +
+            FETCHED_BOTH_ALBUMS +
+            "Refreshing library...\n";
+        for (const json of [false, true]) {
+            stderr.text = "";
+            const dir = mkdtempSync(join(root, "backup-"));
+            const ctx = {
+                ...context(),
+                cacheDir: mkdtempSync(join(root, "cache-")),
+            };
+            expect(await backupCommand(ctx, dir, { json })).toBe(0);
+            expect(stderr.text.slice(0, start.length)).toBe(start);
+        }
     });
 
     it("--verify downloads again an original that does not match its hash, prints the counts, and exits 0", async () => {
@@ -822,6 +1067,7 @@ describe("backup", () => {
                 backupCommand(ctx, dir, {}),
                 new PassThrough(),
                 runStderr,
+                stderrLog(runStderr, "info"),
                 resolve,
             );
         });
@@ -1062,7 +1308,9 @@ describe("helper list-missing-thumbnails", () => {
         expect(stderr.text).toContain("No missing thumbnails found.\n");
     });
 
-    it("prints a JSON array with --json and no progress", async () => {
+    // `--json` shapes stdout only: the progress stays on stderr, and the JSON
+    // takes the place of the count and the list.
+    it("prints a JSON array with --json, and its progress on stderr", async () => {
         const ctx = context(fakeClient({ emptyThumbID: 200 }));
         expect(await listMissingThumbnailsCommand(ctx, { json: true })).toBe(0);
         expect(JSON.parse(stdout.text)).toEqual([
@@ -1073,7 +1321,54 @@ describe("helper list-missing-thumbnails", () => {
                 reason: "empty thumbnail (0 bytes)",
             },
         ]);
-        expect(stderr.text).toBe("");
+        expect(stderr.text).toContain(FETCHED_BOTH_ALBUMS);
+        expect(stderr.text).toContain("[Work] Checking thumbnails...\n");
+        expect(stderr.text).not.toContain("with missing thumbnails");
+    });
+});
+
+describe("helper fix-missing-thumbnails", () => {
+    // File 999 is in no album, so fixing it fails. The list of failed files
+    // is at error, and the last line is fatal, so `-q`, which prints fatal
+    // lines only, still says why the command exits 1.
+    it("lists a failed file at error, and ends with one fatal line counting the failures", async () => {
+        const last = `quak: 1 file(s) failed; see the "Failed files:" list, or the JSON with --json\n`;
+        const ctx = { ...context(), log: stderrLog(stderr, "error") };
+        expect(await fixMissingThumbnailsCommand(ctx, { file: ["999"] })).toBe(
+            1,
+        );
+        expect(stderr.text).toBe(
+            "\nFailed files:\n" +
+                "  999\tunknown\tfile not found in any collection\n" +
+                last,
+        );
+
+        stderr.text = "";
+        const quiet = { ...context(), log: stderrLog(stderr, "fatal") };
+        expect(
+            await fixMissingThumbnailsCommand(quiet, {
+                file: ["999"],
+                json: true,
+            }),
+        ).toBe(1);
+        expect(stderr.text).toBe(last);
+    });
+
+    // beach.jpg (100) is in Vacation (1) and Work (2), both updated at the same
+    // time. The fixer names a file after the first album holding it in the
+    // order of `Library.albums.list()`. On a tie, the album with the higher ID
+    // comes first, so beach.jpg is named after Work.
+    it("names a photo in two albums after the same album on an empty cache as on a cache that holds the account", async () => {
+        const ctx = context(fakeClient({ beachInWork: true }));
+        const opts = { file: ["100"], json: true };
+        const inWork = [{ fileID: 100, collection: "Work", status: "skipped" }];
+        expect(await fixMissingThumbnailsCommand(ctx, opts)).toBe(0);
+        expect(JSON.parse(stdout.text)).toMatchObject(inWork);
+
+        expect(await filesCommand(ctx, undefined, {})).toBe(0);
+        stdout.text = "";
+        expect(await fixMissingThumbnailsCommand(ctx, opts)).toBe(0);
+        expect(JSON.parse(stdout.text)).toMatchObject(inWork);
     });
 });
 
@@ -1103,11 +1398,12 @@ describe("backup-metadata --exif", () => {
     });
 });
 
-// Each test first runs `collections` so the cache holds the account as it was,
+// Each test first runs `files` so the cache holds the account as it was, then
-// then changes the server under it.
+// changes the server under it. (`collections` and `files` with a collection ID
+// would not do: they store nothing.)
 describe("backup-metadata and the thumbnail helpers refresh first", () => {
     beforeEach(async () => {
-        expect(await collectionsCommand(context(), {})).toBe(0);
+        expect(await filesCommand(context(), undefined, {})).toBe(0);
         stdout.text = "";
         stderr.text = "";
     });
@@ -1166,10 +1462,10 @@ describe("backup-metadata and the thumbnail helpers refresh first", () => {
     });
 });
 
-// `files --collection`, `get`, `get-thumb` and `helper fix-missing-thumbnails
+// `files`, `get`, `get-thumb` and `helper fix-missing-thumbnails --file` take
-// --file` take an ID only when it is written in decimal digits and is a safe
+// an ID only when it is written in decimal digits and is a safe integer.
-// integer. `Number()` alone reads `0x10` as 16, `1e3` as 1000 and an empty
+// `Number()` alone reads `0x10` as 16, `1e3` as 1000 and an empty string as 0,
-// string as 0, so the command would act on a file the user never named.
+// so the command would act on a file the user never named.
 // Anything else is refused with one line naming it, and exit 1, before any
 // request.
 //
@@ -1223,21 +1519,18 @@ describe("an ID given on the command line", () => {
 
     it("files looks up a decimal collection ID", async () => {
         const ctx = emptyAccount();
-        expect(await filesCommand(ctx, { collection: "1" })).toBe(1);
+        expect(await filesCommand(ctx, "1", {})).toBe(1);
         expect(stderr.text).toBe("Collection 1 not found\n");
         expect(requests).not.toHaveLength(0);
     });
 
-    it.each(NOT_IDS)(
+    it.each(NOT_IDS)("files refuses %j before any request", async (arg) => {
-        "files refuses --collection %j before any request",
+        const ctx = emptyAccount();
-        async (arg) => {
+        expect(await filesCommand(ctx, arg, {})).toBe(1);
-            const ctx = emptyAccount();
+        expect(stderr.text).toBe(`Invalid collection ID: ${arg}\n`);
-            expect(await filesCommand(ctx, { collection: arg })).toBe(1);
+        expect(stdout.text).toBe("");
-            expect(stderr.text).toBe(`Invalid collection ID: ${arg}\n`);
+        expect(requests).toHaveLength(0);
-            expect(stdout.text).toBe("");
+    });
-            expect(requests).toHaveLength(0);
-        },
-    );
 
     it("get looks up a decimal file ID", async () => {
         expect(await getCommand(emptyAccount(), "100", {})).toBe(1);
@@ -1292,3 +1585,385 @@ describe("an ID given on the command line", () => {
         },
     );
 });
+
+// An account with many albums (issues #210, #217 and #222). On an empty cache
+// `collections`, `files` with a collection ID and `get` used to wait for a
+// refresh that fetched and decrypted the files of every album, one album after
+// another. So did `helper fix-missing-thumbnails --file` (issue #223). On such
+// an account they seemed to hang. The account here has 40 albums of one photo
+// each, encrypted as Ente's clients encrypt them, on the fake Ente server of
+// `test/ente-server.ts`. The tests record the path and query of each request
+// quak sends. The session is the one logging in to that server saves.
+describe("an account with many albums", () => {
+    const ALBUMS = 40;
+    const PASSWORD = "many-albums";
+    const requests: string[] = [];
+    let server: typeof globalThis.fetch;
+    let snapshot: ClientSnapshot;
+
+    // What `files` without a collection ID prints on an empty cache: every
+    // album's photo on stdout, and on stderr each album whose files its
+    // refresh fetched.
+    let everyPhoto = "";
+    let progress = "";
+    for (let n = 1; n <= ALBUMS; n++) {
+        everyPhoto += `${n * 100}\timage\tphoto-${n}.jpg\n`;
+        progress += `Fetched the files of ${n} of ${ALBUMS} collections\n`;
+    }
+
+    // The key of each album, by album ID.
+    const albumKeys = new Map<number, Uint8Array>();
+
+    // A photo in album `collectionID` as the server sends it, and its original
+    // encrypted as the server stores it. The original's bytes are the title.
+    // These tests fetch no thumbnail. The server records a thumbnail size, so
+    // `helper fix-missing-thumbnails` downloads the original before it skips
+    // the photo as not a JPEG.
+    const photoRow = (photo: {
+        id: number;
+        collectionID: number;
+        title: string;
+        updationTime: number;
+    }): { row: Record<string, unknown>; original: Uint8Array } => {
+        const photoKey = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+        const photoKeyBox = encryptSecretbox(
+            photoKey,
+            albumKeys.get(photo.collectionID)!,
+        );
+        const metadata = encryptStreamBlob(
+            new TextEncoder().encode(
+                JSON.stringify({
+                    title: photo.title,
+                    fileType: 0,
+                    creationTime: 1000,
+                    modificationTime: 1000,
+                }),
+            ),
+            photoKey,
+        );
+        const original = encryptStreamBlob(
+            new TextEncoder().encode(photo.title),
+            photoKey,
+        );
+        const row = {
+            id: photo.id,
+            collectionID: photo.collectionID,
+            ownerID: USER_ID,
+            encryptedKey: toBase64(photoKeyBox.ciphertext),
+            keyDecryptionNonce: toBase64(photoKeyBox.nonce),
+            metadata: {
+                encryptedData: toBase64(metadata.ciphertext),
+                decryptionHeader: toBase64(metadata.header),
+            },
+            file: { decryptionHeader: toBase64(original.header) },
+            thumbnail: { decryptionHeader: "" },
+            info: { thumbSize: 1000 },
+            updationTime: photo.updationTime,
+        };
+        return { row, original: original.ciphertext };
+    };
+
+    // Album n is named `Album n` and holds one photo, n * 100, titled
+    // `photo-n.jpg`.
+    beforeAll(async () => {
+        await sodium.ready;
+        const account = await buildAccount(PASSWORD);
+        const collections: Record<string, unknown>[] = [];
+        const filesByCollection: Record<number, Record<string, unknown>[]> = {};
+        const fileCiphertexts: Record<number, Uint8Array> = {};
+        for (let id = 1; id <= ALBUMS; id++) {
+            const albumKey = sodium.crypto_secretbox_keygen();
+            albumKeys.set(id, albumKey);
+            const albumKeyBox = encryptSecretbox(albumKey, account.masterKey);
+            const name = encryptSecretbox(
+                new TextEncoder().encode(`Album ${id}`),
+                albumKey,
+            );
+            collections.push({
+                id,
+                owner: { id: USER_ID },
+                encryptedKey: toBase64(albumKeyBox.ciphertext),
+                keyDecryptionNonce: toBase64(albumKeyBox.nonce),
+                encryptedName: toBase64(name.ciphertext),
+                nameDecryptionNonce: toBase64(name.nonce),
+                type: "album",
+                updationTime: 1,
+            });
+            const { row, original } = photoRow({
+                id: id * 100,
+                collectionID: id,
+                title: `photo-${id}.jpg`,
+                updationTime: 1,
+            });
+            filesByCollection[id] = [row];
+            fileCiphertexts[id * 100] = original;
+        }
+        const ente = buildMetaFetch({
+            verifier: account.verifier,
+            srpAttributes: account.srpAttributes,
+            keyAttributes: account.keyAttributes,
+            encryptedToken: account.encryptedToken,
+            collections,
+            filesByCollection,
+            encryptedMLData: {},
+            fileCiphertexts,
+        });
+        server = (async (input: RequestInfo | URL, init?: RequestInit) => {
+            const url =
+                typeof input === "string"
+                    ? input
+                    : input instanceof URL
+                      ? input.href
+                      : input.url;
+            const { pathname, search } = new URL(url);
+            requests.push(pathname + search);
+            return ente(input, init);
+        }) as typeof globalThis.fetch;
+        const client = await Client.login({
+            email: "many@example.com",
+            password: PASSWORD,
+            apiOptions: { fetch: server },
+        });
+        snapshot = client.toJSON();
+    });
+
+    beforeEach(() => {
+        requests.length = 0;
+    });
+
+    // A context whose saved session sends its requests to `fetch`, by default
+    // the fake server.
+    const accountContext = (fetch = server): CliContext => {
+        const ctx = context();
+        saveSession(ctx.sessionDir, snapshot);
+        return {
+            ...ctx,
+            loadSession: (path) => loadSession(path, { fetch }),
+        };
+    };
+
+    it("collections lists every album from one request, fetching no album's files", async () => {
+        const ctx = accountContext();
+        expect(await collectionsCommand(ctx, {})).toBe(0);
+
+        let albums = "";
+        for (let id = 1; id <= ALBUMS; id++)
+            albums += `${id}\talbum\tAlbum ${id}\n`;
+        expect(stdout.text).toBe(albums);
+        expect(stderr.text).toBe("");
+        expect(requests).toEqual(["/collections/v2?sinceTime=0"]);
+
+        // It stored nothing that would make a refresh skip an album's files:
+        // `files` after it still lists every album's photo.
+        stdout.text = "";
+        expect(await filesCommand(ctx, undefined, {})).toBe(0);
+        expect(stdout.text).toBe(everyPhoto);
+    });
+
+    it("files with a collection ID asks for the album list and that album's files alone", async () => {
+        expect(await filesCommand(accountContext(), "7", {})).toBe(0);
+
+        expect(stdout.text).toBe("700\timage\tphoto-7.jpg\n");
+        expect(stderr.text).toBe("");
+        expect(requests).toEqual([
+            "/collections/v2?sinceTime=0",
+            "/collections/v2/diff?collectionID=7&sinceTime=0",
+        ]);
+    });
+
+    // Here the server sends album 7's files in two pages. Photo 700 changed
+    // between them, so both pages hold a copy of it.
+    it("files with a collection ID lists only the later copy of a photo sent in two pages", async () => {
+        const firstPage = [
+            photoRow({
+                id: 700,
+                collectionID: 7,
+                title: "photo-7.jpg",
+                updationTime: 1,
+            }).row,
+            photoRow({
+                id: 701,
+                collectionID: 7,
+                title: "photo-701.jpg",
+                updationTime: 1,
+            }).row,
+        ];
+        const secondPage = [
+            photoRow({
+                id: 700,
+                collectionID: 7,
+                title: "photo-7-edited.jpg",
+                updationTime: 2,
+            }).row,
+        ];
+        const paged = (async (input: RequestInfo | URL, init?: RequestInit) => {
+            const url = new URL(input instanceof Request ? input.url : input);
+            if (
+                url.pathname !== "/collections/v2/diff" ||
+                url.searchParams.get("collectionID") !== "7"
+            ) {
+                return server(input, init);
+            }
+            const first = url.searchParams.get("sinceTime") === "0";
+            return new Response(
+                JSON.stringify({
+                    diff: first ? firstPage : secondPage,
+                    hasMore: first,
+                }),
+            );
+        }) as typeof globalThis.fetch;
+
+        expect(await filesCommand(accountContext(paged), "7", {})).toBe(0);
+
+        // Photo 700 is listed once, with the later title, before photo 701.
+        expect(stdout.text).toBe(
+            "700\timage\tphoto-7-edited.jpg\n701\timage\tphoto-701.jpg\n",
+        );
+    });
+
+    // The cache stays empty, so a later `files` without a collection ID still
+    // fetches the files of all 40 albums.
+    it("files with a collection ID stores nothing in the cache", async () => {
+        const ctx = accountContext();
+        expect(await filesCommand(ctx, "7", {})).toBe(0);
+        expect(existsSync(join(root, "cache", "metadata.json"))).toBe(false);
+
+        stdout.text = "";
+        expect(await filesCommand(ctx, undefined, {})).toBe(0);
+        expect(stdout.text).toBe(everyPhoto);
+        expect(stderr.text).toBe(progress);
+    });
+
+    // Photo 200 is in album 2, so `get` asks for no file of album 3 or later.
+    // The last request downloads the photo's original.
+    it("get on an empty cache asks for the albums' files only until one holds the photo", async () => {
+        const out = join(root, "photo.jpg");
+        expect(await getCommand(accountContext(), "200", { out })).toBe(0);
+
+        expect(readFileSync(out, "utf-8")).toBe("photo-2.jpg");
+        expect(stderr.text).toBe(`11 bytes -> ${out}\n`);
+        expect(requests).toEqual([
+            "/collections/v2?sinceTime=0",
+            "/collections/v2/diff?collectionID=1&sinceTime=0",
+            "/collections/v2/diff?collectionID=2&sinceTime=0",
+            "/?fileID=200",
+        ]);
+        expect(existsSync(join(root, "cache", "metadata.json"))).toBe(false);
+    });
+
+    // `files` first fills the cache, so `get` waits for a refresh. No album has
+    // changed since, so the refresh asks for no album's files.
+    it("get on a cache that holds the account asks for no unchanged album's files, also for a photo in no album", async () => {
+        const ctx = accountContext();
+        expect(await filesCommand(ctx, undefined, {})).toBe(0);
+        requests.length = 0;
+        stderr.text = "";
+
+        const out = join(root, "photo.jpg");
+        expect(await getCommand(ctx, "4000", { out })).toBe(0);
+        expect(readFileSync(out, "utf-8")).toBe("photo-40.jpg");
+        expect(stderr.text).toBe(`12 bytes -> ${out}\n`);
+        expect(requests).toEqual([
+            "/collections/v2?sinceTime=1",
+            "/?fileID=4000",
+        ]);
+
+        requests.length = 0;
+        stderr.text = "";
+        expect(await getCommand(ctx, "999", { out })).toBe(1);
+        expect(stderr.text).toBe("File 999 not found\n");
+        expect(requests).toEqual(["/collections/v2?sinceTime=1"]);
+    });
+
+    // The helper searches the most recently updated album first. All 40 were
+    // updated at the same time, and on a tie the higher ID comes first. Photo
+    // 3900 is in album 39, so the helper asks for no file of album 38 or
+    // earlier. The last request downloads the photo's original.
+    it("fix-missing-thumbnails --file on an empty cache asks for the albums' files only until one holds the photo", async () => {
+        const opts = { file: ["3900"], json: true };
+        expect(await fixMissingThumbnailsCommand(accountContext(), opts)).toBe(
+            0,
+        );
+
+        const reason =
+            "unsupported image format (only baseline JPEG can be regenerated)";
+        expect(JSON.parse(stdout.text)).toEqual([
+            {
+                fileID: 3900,
+                title: "photo-39.jpg",
+                collection: "Album 39",
+                status: "skipped",
+                reason,
+            },
+        ]);
+        expect(stderr.text).toBe(
+            "[Album 39] Downloading photo-39.jpg for thumbnail generation...\n" +
+                `[Album 39] Skipping photo-39.jpg: ${reason}\n`,
+        );
+        expect(requests).toEqual([
+            "/collections/v2?sinceTime=0",
+            "/collections/v2/diff?collectionID=40&sinceTime=0",
+            "/collections/v2/diff?collectionID=39&sinceTime=0",
+            "/?fileID=3900",
+        ]);
+        expect(existsSync(join(root, "cache", "metadata.json"))).toBe(false);
+    });
+
+    // `files` first fills the cache, so the helper waits for a refresh. No
+    // album has changed since, so the refresh asks for no album's files.
+    it("fix-missing-thumbnails --file on a cache that holds the account asks for no unchanged album's files, also for a photo in no album", async () => {
+        const ctx = accountContext();
+        expect(await filesCommand(ctx, undefined, {})).toBe(0);
+        requests.length = 0;
+        stdout.text = "";
+        stderr.text = "";
+
+        const opts = { file: ["3900"], json: true };
+        expect(await fixMissingThumbnailsCommand(ctx, opts)).toBe(0);
+        const reason =
+            "unsupported image format (only baseline JPEG can be regenerated)";
+        expect(JSON.parse(stdout.text)).toEqual([
+            {
+                fileID: 3900,
+                title: "photo-39.jpg",
+                collection: "Album 39",
+                status: "skipped",
+                reason,
+            },
+        ]);
+        expect(stderr.text).toBe(
+            "[Album 39] Downloading photo-39.jpg for thumbnail generation...\n" +
+                `[Album 39] Skipping photo-39.jpg: ${reason}\n`,
+        );
+        expect(requests).toEqual([
+            "/collections/v2?sinceTime=1",
+            "/?fileID=3900",
+        ]);
+
+        requests.length = 0;
+        stdout.text = "";
+        const notFound = { file: ["999"], json: true };
+        expect(await fixMissingThumbnailsCommand(ctx, notFound)).toBe(1);
+        expect(JSON.parse(stdout.text)).toMatchObject([
+            { fileID: 999, reason: "file not found in any collection" },
+        ]);
+        expect(requests).toEqual(["/collections/v2?sinceTime=1"]);
+    });
+
+    it("files counts on stderr each album whose files its refresh fetched", async () => {
+        expect(await filesCommand(accountContext(), undefined, {})).toBe(0);
+
+        expect(stdout.text).toBe(everyPhoto);
+        expect(stderr.text).toBe(progress);
+    });
+
+    // `--json` shapes stdout only, so the refresh's progress is still counted
+    // on stderr.
+    it("files --json counts on stderr each album whose files its refresh fetched", async () => {
+        const opts = { json: true };
+        expect(await filesCommand(accountContext(), undefined, opts)).toBe(0);
+
+        expect(JSON.parse(stdout.text)).toHaveLength(ALBUMS);
+        expect(stderr.text).toBe(progress);
+    });
+});

test/cli/log.test.ts

@@ -0,0 +1,359 @@
+/**
+ * Tests for the CLI's log levels, set with `-v`/`--verbose` and `-q`/`--quiet`
+ * (`src/cli-log.ts`, issue #212).
+ *
+ * Every line quak prints on stderr is a log line at one of six levels, from
+ * the quietest: fatal, error, warning, info, debug, trace. A run prints the
+ * lines at its own level and at every quieter one. The level is info unless
+ * asked otherwise: `-v` raises it to debug, `-vv` to trace, and more repeats
+ * stay at trace. `-q` lowers it to fatal, so a run prints only the line a
+ * command prints as it fails with a non-zero exit code. stdout holds the
+ * command's output at every level.
+ *
+ * Most tests run `bin/quak.ts`, as the smoke test does, against an account of
+ * one album holding one photo: the saved session is in a temporary directory,
+ * and `fetch` is a fake of the Ente server that serves the album and the photo
+ * encrypted as Ente's clients encrypt them. Each run has a cache directory of
+ * its own, so its refresh fetches the album's files, as on a first run.
+ */
+
+import { mkdtempSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import sodium from "libsodium-wrappers-sumo";
+import {
+    afterAll,
+    afterEach,
+    beforeAll,
+    describe,
+    expect,
+    it,
+    vi,
+} from "vitest";
+
+import { ApiClient } from "../../src/api/client.js";
+import { saveSession } from "../../src/cli-commands.js";
+import { logRefresh, logRequests, type Log } from "../../src/cli-log.js";
+import { init, toBase64 } from "../../src/crypto/index.js";
+import { encryptSecretbox, encryptStreamBlob } from "../ente-server.js";
+
+// `bin/quak.ts` reads the saved session from the data directory env-paths
+// gives it, which here is a temporary directory made before the first run.
+const paths = vi.hoisted(() => ({ data: "" }));
+vi.mock("env-paths", () => ({ default: () => paths }));
+
+const USER_ID = 42;
+const root = mkdtempSync(join(tmpdir(), "quak-log-test-"));
+const argv = process.argv;
+
+class ExitCalled extends Error {}
+
+// Run `quak <args>` to its exit, with a cache of its own, and return its exit
+// code and what it wrote on stdout and on stderr, which are kept off the
+// terminal. `process.exit` is stubbed to throw, so nothing runs after it, as
+// nothing does after a real exit.
+const quak = async (
+    ...args: string[]
+): Promise<{ code: number; stdout: string; stderr: string }> => {
+    let stdout = "";
+    let stderr = "";
+    let code = NaN;
+    vi.spyOn(process.stdout, "write").mockImplementation((text) => {
+        stdout += String(text);
+        return true;
+    });
+    vi.spyOn(process.stderr, "write").mockImplementation((text) => {
+        stderr += String(text);
+        return true;
+    });
+    vi.spyOn(process, "exit").mockImplementation((exitCode) => {
+        code = Number(exitCode ?? 0);
+        throw new ExitCalled();
+    });
+    const cache = mkdtempSync(join(root, "cache-"));
+    process.argv = ["node", "quak", "--cache-dir", cache, ...args];
+    vi.resetModules();
+    await expect(import("../../bin/quak.js")).rejects.toBeInstanceOf(
+        ExitCalled,
+    );
+    return { code, stdout, stderr };
+};
+
+// Album 1, "Trips", of user 42, holding photo 100, "beach.jpg". The album's
+// key is encrypted with the account's master key, the photo's key with the
+// album's, and the photo's metadata with its own key. Only the session and
+// these two records are needed: the tests never log in.
+beforeAll(async () => {
+    await init();
+    await sodium.ready;
+    const masterKey = sodium.crypto_secretbox_keygen();
+    const keyPair = sodium.crypto_box_keypair();
+    paths.data = join(root, "session");
+    saveSession(paths.data, {
+        email: "log@example.com",
+        userID: USER_ID,
+        token: "token",
+        masterKey: toBase64(masterKey),
+        secretKey: toBase64(keyPair.privateKey),
+        publicKey: toBase64(keyPair.publicKey),
+    });
+
+    const albumKey = sodium.crypto_secretbox_keygen();
+    const albumKeyBox = encryptSecretbox(albumKey, masterKey);
+    const name = encryptSecretbox(new TextEncoder().encode("Trips"), albumKey);
+    const album = {
+        id: 1,
+        owner: { id: USER_ID },
+        encryptedKey: toBase64(albumKeyBox.ciphertext),
+        keyDecryptionNonce: toBase64(albumKeyBox.nonce),
+        encryptedName: toBase64(name.ciphertext),
+        nameDecryptionNonce: toBase64(name.nonce),
+        type: "album",
+        updationTime: 1,
+    };
+    const photoKey = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+    const photoKeyBox = encryptSecretbox(photoKey, albumKey);
+    const metadata = encryptStreamBlob(
+        new TextEncoder().encode(
+            JSON.stringify({
+                title: "beach.jpg",
+                fileType: 0,
+                creationTime: 1000,
+                modificationTime: 1000,
+            }),
+        ),
+        photoKey,
+    );
+    const photo = {
+        id: 100,
+        collectionID: 1,
+        ownerID: USER_ID,
+        encryptedKey: toBase64(photoKeyBox.ciphertext),
+        keyDecryptionNonce: toBase64(photoKeyBox.nonce),
+        metadata: {
+            encryptedData: toBase64(metadata.ciphertext),
+            decryptionHeader: toBase64(metadata.header),
+        },
+        // These tests fetch no original and no thumbnail.
+        file: { decryptionHeader: "" },
+        thumbnail: { decryptionHeader: "" },
+        updationTime: 1,
+    };
+
+    const json = (body: unknown): Response =>
+        new Response(JSON.stringify(body), {
+            headers: { "content-type": "application/json" },
+        });
+    vi.stubGlobal("fetch", async (input: string) => {
+        const { pathname } = new URL(input);
+        if (pathname === "/collections/v2") {
+            return json({ collections: [album] });
+        }
+        if (pathname === "/collections/v2/diff") {
+            return json({ diff: [photo], hasMore: false });
+        }
+        return new Response("not found", { status: 404 });
+    });
+});
+
+afterEach(() => {
+    process.argv = argv;
+    vi.restoreAllMocks();
+});
+
+afterAll(() => {
+    vi.unstubAllGlobals();
+    rmSync(root, { recursive: true, force: true });
+});
+
+// What `quak files` writes on stdout at every level.
+const FILES = "100\timage\tbeach.jpg\n";
+
+// What it writes on stderr at each level. Info is the refresh's progress, one
+// line for the one album whose files it fetched. Debug adds the start and end
+// of the refresh, and trace each request with the status of its answer.
+const INFO = "Fetched the files of 1 of 1 collections\n";
+const DEBUG = "Refresh started\n" + INFO + "Refresh done\n";
+const TRACE =
+    "Refresh started\n" +
+    "GET https://api.ente.io/collections/v2?sinceTime=0: HTTP 200\n" +
+    "GET https://api.ente.io/collections/v2/diff?collectionID=1&sinceTime=0: HTTP 200\n" +
+    INFO +
+    "Refresh done\n";
+
+describe("the log level", () => {
+    it("is info by default", async () => {
+        expect(await quak("files")).toEqual({
+            code: 0,
+            stdout: FILES,
+            stderr: INFO,
+        });
+    });
+
+    it("is debug with -v", async () => {
+        expect(await quak("-v", "files")).toEqual({
+            code: 0,
+            stdout: FILES,
+            stderr: DEBUG,
+        });
+    });
+
+    it("is trace with -vv", async () => {
+        expect(await quak("-vv", "files")).toEqual({
+            code: 0,
+            stdout: FILES,
+            stderr: TRACE,
+        });
+    });
+
+    it("stays at trace with -vvv", async () => {
+        expect((await quak("-vvv", "files")).stderr).toBe(TRACE);
+    });
+
+    it("counts --verbose --verbose as -vv", async () => {
+        expect((await quak("--verbose", "--verbose", "files")).stderr).toBe(
+            TRACE,
+        );
+    });
+
+    // Both are options of the program, taken before or after the command's
+    // name, as `--cache-dir` is.
+    it("is set by an option after the command's name too", async () => {
+        expect((await quak("files", "-v")).stderr).toBe(DEBUG);
+        expect((await quak("files", "--json", "-vv")).stderr).toBe(TRACE);
+        expect((await quak("files", "-q")).stderr).toBe("");
+    });
+});
+
+describe("-q", () => {
+    it("prints nothing on stderr when the command works", async () => {
+        expect(await quak("-q", "files")).toEqual({
+            code: 0,
+            stdout: FILES,
+            stderr: "",
+        });
+    });
+
+    // No album holds file 999, so fixing it fails. The summary from
+    // `--- Done ---` to the end of the `Failed files:` list is left out. The
+    // line saying why the command failed is the fatal one, and it is printed.
+    it("prints only the line a failing command exits with", async () => {
+        const fix = ["helper", "fix-missing-thumbnails", "--file", "999"];
+        expect(await quak("-q", ...fix)).toEqual({
+            code: 1,
+            stdout: "",
+            stderr: `quak: 1 file(s) failed; see the "Failed files:" list, or the JSON with --json\n`,
+        });
+    });
+
+    it("is refused with -v, in one line, before the command runs", async () => {
+        for (const args of [
+            ["-q", "-v", "files"],
+            ["files", "--verbose", "--quiet"],
+        ]) {
+            const { code, stdout, stderr } = await quak(...args);
+            expect(code).toBe(1);
+            expect(stdout).toBe("");
+            expect(stderr).toBe(
+                "error: option '-q, --quiet' cannot be used with option '-v, --verbose'\n",
+            );
+        }
+    });
+});
+
+// `--help` lists both options, and each command's help lists them too, since
+// each command takes them.
+describe("--help", () => {
+    it("lists -v and -q for the program and for each command", async () => {
+        for (const args of [["--help"], ["files", "--help"]]) {
+            const { stdout } = await quak(...args);
+            expect(stdout).toContain("-v, --verbose");
+            expect(stdout).toContain("-q, --quiet");
+        }
+    });
+});
+
+// The library writes no lines itself. Its layers report through callbacks,
+// and the CLI logs what they report.
+describe("what the library reports", () => {
+    const collect = (): { log: Log; lines: string[] } => {
+        const lines: string[] = [];
+        return { log: (level, line) => lines.push(`${level}: ${line}`), lines };
+    };
+
+    // A request answered 503 and retried: each attempt is a request, logged
+    // at trace with its status, and the retry is logged at debug with how
+    // long it waits and why.
+    it("logs each request at trace and each retry at debug", async () => {
+        const { log, lines } = collect();
+        const answers = [
+            new Response("unavailable", { status: 503 }),
+            new Response("{}", {
+                headers: { "content-type": "application/json" },
+            }),
+        ];
+        const client = new ApiClient({
+            ...logRequests(log, {
+                sleep: async () => {},
+                random: () => 0.5,
+            }),
+            fetch: async () => answers.shift()!,
+        });
+
+        await client.getJSON("/collections/v2", { sinceTime: 0 });
+
+        const url = "https://api.ente.io/collections/v2?sinceTime=0";
+        expect(lines).toEqual([
+            `trace: GET ${url}: HTTP 503`,
+            "debug: Attempt 1 failed, retrying in 250 ms: HTTP 503",
+            `trace: GET ${url}: HTTP 200`,
+        ]);
+    });
+
+    it("logs a request that failed with its error", async () => {
+        const { log, lines } = collect();
+        const client = new ApiClient({
+            ...logRequests(log, { attempts: 1 }),
+            fetch: async () => {
+                throw new TypeError("fetch failed", {
+                    cause: new Error("connect ECONNREFUSED 1.2.3.4:443"),
+                });
+            },
+        });
+
+        await expect(client.getJSON("/collections/v2")).rejects.toThrow();
+
+        expect(lines).toEqual([
+            "trace: GET https://api.ente.io/collections/v2: fetch failed: connect ECONNREFUSED 1.2.3.4:443",
+        ]);
+    });
+
+    // Each operation is named in plain words.
+    it("logs a refresh's progress at info, and its start and end at debug", () => {
+        const { log, lines } = collect();
+        const onProgress = logRefresh(log);
+
+        onProgress({ operation: "refresh", status: "started" });
+        onProgress({
+            operation: "refresh",
+            status: "progress",
+            fetched: 1,
+            total: 2,
+        });
+        onProgress({
+            operation: "refresh",
+            status: "failed",
+            error: "HTTP 503",
+        });
+        onProgress({ operation: "fetchMLData", status: "started" });
+        onProgress({ operation: "fetchMLData", status: "done", fetched: 3 });
+
+        expect(lines).toEqual([
+            "debug: Refresh started",
+            "info: Fetched the files of 1 of 2 collections",
+            "debug: Refresh failed: HTTP 503",
+            "debug: ML data fetch started",
+            "debug: ML data fetch done",
+        ]);
+    });
+});

test/cli/metadata-backup.test.ts

@@ -41,12 +41,14 @@ import { beforeAll, afterAll, describe, expect, it, vi } from "vitest";
 import { init, toBase64, encryptBlob } from "../../src/crypto/index.js";
 import * as jpegJs from "jpeg-js";
 import { Client } from "../../src/client.js";
+import { DISCOVER_CATEGORIES } from "../../src/clip-keyword-vectors.js";
 import { Library } from "../../src/library/index.js";
 import {
     runMetadataBackup,
     type MetadataBackupOptions,
 } from "../../src/metadata-backup.js";
 import { backupMetadataCommand } from "../../src/cli-commands.js";
+import { stderrLog, type LogLevel } from "../../src/cli-log.js";
 import {
     buildAccount,
     buildMetaFetch,
@@ -55,8 +57,8 @@ import {
     type MetaMockState,
 } from "../ente-server.js";
 
-// One file per ML data request, so the two files of the mock account are
+// One file per ML data request, so each file of the mock account is fetched in
-// fetched in two requests and one of them can fail on its own.
+// a request of its own and one of them can fail on its own.
 vi.mock("../../src/mldata-fetch.js", async (importOriginal) => ({
     ...(await importOriginal<typeof import("../../src/mldata-fetch.js")>()),
     MLDATA_BATCH_SIZE: 1,
@@ -65,6 +67,21 @@ vi.mock("../../src/mldata-fetch.js", async (importOriginal) => ({
 const TEST_EMAIL = "metabackup@example.com";
 const TEST_PASSWORD = "metapass";
 
+// The CLIP embedding of a photo of a sunset (see clip-keywords.test.ts), which
+// the ML data of beach.jpg holds.
+const SUNSET_EMBEDDING: number[] = JSON.parse(
+    readFileSync(
+        new URL("../clip-keywords-sunset.json", import.meta.url),
+        "utf-8",
+    ),
+).embedding;
+
+// Identity, a Discover category of Ente's photos app that leaves out videos.
+const IDENTITY = DISCOVER_CATEGORIES.find((c) => c.title === "Identity")!;
+
+// ML data holding faces and no CLIP embedding, which file 302 has.
+const FACES_ONLY = { face: { faces: [{ faceID: "face-def", score: 0.9 }] } };
+
 let mock: MetaMockState;
 let testDir: string;
 
@@ -203,6 +220,65 @@ const buildMetaMock = async (): Promise<MetaMockState> => {
         updationTime: 1710000000000000,
     };
 
+    // A file in coll 10 with the ML data given. `fileType` is Ente's number: 0
+    // an image, 1 a video.
+    const vacationFile = (
+        id: number,
+        title: string,
+        fileType: number,
+        mlData: object,
+    ) => {
+        const fileKey = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+        const { ciphertext: encKey, nonce } = encryptSecretbox(fileKey, ck1);
+        const meta = encryptStreamBlob(
+            new TextEncoder().encode(
+                JSON.stringify({
+                    title,
+                    fileType,
+                    creationTime: 1700000000000000,
+                    modificationTime: 1700000000000000,
+                }),
+            ),
+            fileKey,
+        );
+        const ml = encryptBlob(
+            new Uint8Array(gzipSync(Buffer.from(JSON.stringify(mlData)))),
+            fileKey,
+        );
+        return {
+            raw: {
+                id,
+                collectionID: 10,
+                ownerID: 42,
+                encryptedKey: toBase64(encKey),
+                keyDecryptionNonce: toBase64(nonce),
+                metadata: {
+                    encryptedData: toBase64(meta.ciphertext),
+                    decryptionHeader: toBase64(meta.header),
+                },
+                file: {
+                    decryptionHeader: toBase64(sodium.randombytes_buf(24)),
+                },
+                thumbnail: {
+                    decryptionHeader: toBase64(sodium.randombytes_buf(24)),
+                },
+                updationTime: 1700000000000000,
+            },
+            mlData: {
+                encryptedData: toBase64(ml.ciphertext),
+                decryptionHeader: toBase64(ml.header),
+            },
+        };
+    };
+    // Files 300 and 301 in coll 10: a photo and a video whose ML data holds
+    // only a CLIP embedding, Identity's own text embedding.
+    const identityML = { clip: { embedding: IDENTITY.textEmbedding } };
+    const identityPhoto = vacationFile(300, "passport.jpg", 0, identityML);
+    const identityVideo = vacationFile(301, "passport.mp4", 1, identityML);
+    // File 302 in coll 10: a photo whose ML data holds faces and no CLIP
+    // embedding.
+    const facesPhoto = vacationFile(302, "party.jpg", 0, FACES_ONLY);
+
     // Encrypt ML data for file 100 (gzipped JSON, encrypted with file key)
     const mlPayload = JSON.stringify({
         face: {
@@ -229,7 +305,7 @@ const buildMetaMock = async (): Promise<MetaMockState> => {
         clip: {
             version: 1,
             client: "test",
-            embedding: [0.5, 0.6, 0.7],
+            embedding: SUNSET_EMBEDDING,
         },
     });
     const gzipped = gzipSync(Buffer.from(mlPayload));
@@ -269,12 +345,23 @@ const buildMetaMock = async (): Promise<MetaMockState> => {
         keyAttributes: account.keyAttributes,
         encryptedToken: account.encryptedToken,
         collections: [rawColl1, rawColl2],
-        filesByCollection: { 10: [rawFile1], 20: [rawFile2] },
+        filesByCollection: {
+            10: [
+                rawFile1,
+                identityPhoto.raw,
+                identityVideo.raw,
+                facesPhoto.raw,
+            ],
+            20: [rawFile2],
+        },
         encryptedMLData: {
             100: {
                 encryptedData: toBase64(mlCiphertext),
                 decryptionHeader: toBase64(mlHeader),
             },
+            300: identityPhoto.mlData,
+            301: identityVideo.mlData,
+            302: facesPhoto.mlData,
         },
         fileCiphertexts: { 100: encFileBody1 },
     };
@@ -431,7 +518,9 @@ describe("quak backup-metadata", () => {
         expect(account.email).toBe(TEST_EMAIL);
     });
 
-    it("fetches and decrypts ML data by default", async () => {
+    // The CLIP embedding is left out of the ML data, and the keywords it gives
+    // are written in its place.
+    it("fetches and decrypts ML data by default, with keywords for the CLIP embedding", async () => {
         const outDir = join(testDir, "ml-data");
         await runBackup(outDir);
 
@@ -451,8 +540,41 @@ describe("quak backup-metadata", () => {
         expect(fileMeta.mlData.face.faces[0].faceID).toBe("face-abc");
         expect(fileMeta.mlData.face.faces[0].score).toBeCloseTo(0.98);
         expect(fileMeta.mlData.face.faces[0].detection.box.x).toBeCloseTo(0.1);
-        expect(fileMeta.mlData.clip).toBeDefined();
+        expect(fileMeta.mlData).not.toHaveProperty("clip");
-        expect(fileMeta.mlData.clip.embedding).toEqual([0.5, 0.6, 0.7]);
+        expect(fileMeta.keywords).toEqual(["Sunset"]);
+    });
+
+    // Ente's photos app keeps videos out of some Discover categories, Identity
+    // among them. Files 300 and 301, a photo and a video, share one CLIP
+    // embedding, Identity's own text embedding, so the photo gets the keyword
+    // Identity and the video does not.
+    it("keeps a video out of a category that leaves out videos", async () => {
+        expect(IDENTITY.showVideo).toBe(false);
+        const outDir = join(testDir, "video-keywords");
+        await runBackup(outDir);
+
+        const vacation = join(outDir, "collections", "10-Vacation");
+        const fileJSON = (fileID: number) =>
+            JSON.parse(readFileSync(join(vacation, `${fileID}.json`), "utf-8"));
+        expect(fileJSON(300).keywords).toContain("Identity");
+        expect(fileJSON(301)).toHaveProperty("keywords");
+        expect(fileJSON(301).keywords).not.toContain("Identity");
+    });
+
+    // A file's ML data can hold faces and no CLIP embedding. File 302's JSON
+    // then has the ML data and no keywords.
+    it("writes no keywords for ML data without a CLIP embedding", async () => {
+        const outDir = join(testDir, "no-clip");
+        await runBackup(outDir);
+
+        const fileMeta = JSON.parse(
+            readFileSync(
+                join(outDir, "collections", "10-Vacation", "302.json"),
+                "utf-8",
+            ),
+        );
+        expect(fileMeta.mlData).toEqual(FACES_ONLY);
+        expect(fileMeta).not.toHaveProperty("keywords");
     });
 
     it("extracts EXIF from downloaded files when --exif is set", async () => {
@@ -489,15 +611,18 @@ describe("quak backup-metadata", () => {
     });
 });
 
-describe("quak backup-metadata when an ML data request fails", () => {
+describe("quak backup-metadata when a file's ML data cannot be read", () => {
-    // Run the CLI command against the mock and return its exit code, stderr
+    // Run the CLI command against `fetch`, the mock unless given, logging at
-    // and output directory.
+    // `level`, and return its exit code, stderr and output directory.
-    const runCommand = async (failMLDataFor?: number) => {
+    const runCommand = async (
+        fetch = buildMetaFetch(mock),
+        level: LogLevel = "info",
+    ) => {
         const client = await Client.login({
             email: TEST_EMAIL,
             password: TEST_PASSWORD,
             apiOptions: {
-                fetch: buildMetaFetch(mock, failMLDataFor),
+                fetch,
                 retry: { sleep: async () => {} },
             },
         });
@@ -506,7 +631,10 @@ describe("quak backup-metadata when an ML data request fails", () => {
         const code = await backupMetadataCommand(
             {
                 stdout: { write: () => true },
-                stderr: { write: (text: string) => (stderr += text) },
+                log: stderrLog(
+                    { write: (text: string) => (stderr += text) },
+                    level,
+                ),
                 sessionDir: testDir,
                 cacheDir: mkdtempSync(join(testDir, "cache-")),
                 loadSession: () => client,
@@ -517,11 +645,16 @@ describe("quak backup-metadata when an ML data request fails", () => {
         return { code, stderr, outDir };
     };
 
+    // The failed request is logged at error, so it is the first line printed
+    // at that level.
     it("writes every file, marks the failed batch's files, and exits 1", async () => {
-        const { code, stderr, outDir } = await runCommand(200);
+        const { code, stderr, outDir } = await runCommand(
+            buildMetaFetch(mock, 200),
+            "error",
+        );
 
         expect(code).toBe(1);
-        expect(stderr).toContain("ML data request for 1 file(s) failed");
+        expect(stderr).toMatch(/^ML data request for 1 file\(s\) failed: /);
 
         const ok = JSON.parse(
             readFileSync(
@@ -529,7 +662,7 @@ describe("quak backup-metadata when an ML data request fails", () => {
                 "utf-8",
             ),
         );
-        expect(ok.mlData.clip.embedding).toEqual([0.5, 0.6, 0.7]);
+        expect(ok.keywords).toEqual(["Sunset"]);
         expect(ok.mlDataError).toBeUndefined();
 
         const failed = JSON.parse(
@@ -543,6 +676,53 @@ describe("quak backup-metadata when an ML data request fails", () => {
         expect(failed.mlDataError).toContain("500");
     });
 
+    // The server sends ML data for diagram.png encrypted under a key that is
+    // not the file's, so quak cannot decrypt it. That is logged at error, and
+    // the last line is fatal, so `-q`, which prints fatal lines only, still
+    // says why the command exits 1.
+    it("writes the reason for ML data that does not decrypt, and exits 1", async () => {
+        const otherKey = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+        const { header, ciphertext } = encryptBlob(
+            new Uint8Array(gzipSync(Buffer.from("{}"))),
+            otherKey,
+        );
+        const { code, stderr, outDir } = await runCommand(
+            buildMetaFetch({
+                ...mock,
+                encryptedMLData: {
+                    ...mock.encryptedMLData,
+                    200: {
+                        encryptedData: toBase64(ciphertext),
+                        decryptionHeader: toBase64(header),
+                    },
+                },
+            }),
+            "error",
+        );
+
+        expect(code).toBe(1);
+        const reason = "secretstream chunk authentication failed";
+        expect(stderr).toBe(
+            `ML data of file 200 could not be read: ${reason}\n` +
+                `quak: the ML data of 1 file(s) could not be read; see mlDataError in their JSON in ${outDir}\n`,
+        );
+        const failed = JSON.parse(
+            readFileSync(
+                join(outDir, "collections", "20-__Work", "200.json"),
+                "utf-8",
+            ),
+        );
+        expect(failed.mlData).toBeUndefined();
+        expect(failed.mlDataError).toBe(reason);
+        const ok = JSON.parse(
+            readFileSync(
+                join(outDir, "collections", "10-Vacation", "100.json"),
+                "utf-8",
+            ),
+        );
+        expect(ok.keywords).toEqual(["Sunset"]);
+    });
+
     it("exits 0 when every ML data request succeeds", async () => {
         const { code } = await runCommand();
         expect(code).toBe(0);

test/cli/read.test.ts

@@ -3,17 +3,25 @@
  * issue #36, issue #52).
  *
  * The `collections`, `files`, `get`, and `get-thumb` commands must answer for
- * current server state, not the local cache, so each helper forces a
+ * current server state, not the local cache. `get`, `get-thumb` and `files`
- * `Library.fresh()` round-trip before it reads. The stand-in library below
+ * without a collection ID force a `Library.fresh()` round-trip before they
- * serves nothing until `fresh()` has been awaited, so a helper that read
+ * read. The stand-in library below serves no cached record until `fresh()` has
- * without refreshing would come back empty and fail here.
+ * been awaited, so a helper that read without refreshing would come back empty
+ * and fail here. `collections` asks the library for the collection list alone
+ * (`freshCollections()`, issue #210). `files` with a collection ID asks for
+ * that list, then for that one collection's files (`freshFiles()`, issue
+ * #217). Neither may wait for a refresh, which would fetch the files of every
+ * collection. On an empty cache, `get` and `get-thumb` ask for that list, then
+ * for one collection's files at a time, until they find the file (issue #222).
+ * `helper fix-missing-thumbnails --file` does the same until it finds every
+ * file it names, reading the most recently updated collection first (issue
+ * #223).
  *
- * `collections` and `files` also list in the library's enumeration order
+ * `collections` and `files` also list in the order the library gives them, not
- * (`listCollections`/`listFiles`) — the order the pre-library CLI printed — not
  * the albums/photos projection's newest-first order. The fixtures are seeded in
- * an enumeration order that a newest-first sort would rearrange, so a
+ * an order that a newest-first sort would rearrange, so a regression to the
- * regression to the projection order would fail here too. Field values still
+ * projection order would fail here too. Field values still come from the raw
- * come from the raw metadata via `cli-output.ts`.
+ * metadata via `cli-output.ts`.
  */
 
 import { describe, it, expect } from "vitest";
@@ -22,10 +30,10 @@ import {
     freshCollections,
     freshFiles,
     freshFile,
+    freshFilesByID,
     type FreshReadLibrary,
 } from "../../src/cli-read.js";
 import { fileListRow } from "../../src/cli-output.js";
-import type { Photo } from "../../src/library/index.js";
 import type { Collection, EnteFile } from "../../src/model/types.js";
 
 const collection = (id: number, updationTime: number): Collection => ({
@@ -59,11 +67,15 @@ const file = (
     updationTime: creationTime,
 });
 
-// A library that reveals its records only after `fresh()` has been awaited, and
+// A library that reveals its cached records only after `fresh()` has been
-// serves them in the enumeration order it was given. `photos.byID` returns a
+// awaited, and serves them in the enumeration order it was given.
-// stand-in `Photo` carrying just the fileID the helper passes through.
+// `freshCollections()` and `freshFiles()` answer in that order without a
+// refresh.
 class FakeLibrary implements FreshReadLibrary {
     freshCalls = 0;
+    freshCollectionsCalls = 0;
+    // The ID of each collection `freshFiles()` was asked for.
+    freshFilesCalls: number[] = [];
     private refreshed = false;
 
     constructor(
@@ -77,12 +89,18 @@ class FakeLibrary implements FreshReadLibrary {
         return {};
     }
 
-    listCollections(): Collection[] {
+    async freshCollections(): Promise<Collection[]> {
-        return this.refreshed ? this.collections : [];
+        this.freshCollectionsCalls++;
+        return this.collections;
     }
 
-    getCollection(id: number): Collection | undefined {
+    async freshFiles(collection: Collection): Promise<EnteFile[]> {
-        return this.listCollections().find((c) => c.id === id);
+        this.freshFilesCalls.push(collection.id);
+        return this.files.filter((f) => f.collectionID === collection.id);
+    }
+
+    listCollections(): Collection[] {
+        return this.refreshed ? this.collections : [];
     }
 
     listFiles(collectionID: number): EnteFile[] {
@@ -95,18 +113,10 @@ class FakeLibrary implements FreshReadLibrary {
         if (!this.refreshed) return undefined;
         return this.files.find((f) => f.id === fileID);
     }
-
-    photos = {
-        byID: ({ fileID }: { fileID: number }): Photo | undefined => {
-            if (!this.refreshed) return undefined;
-            if (!this.files.some((f) => f.id === fileID)) return undefined;
-            return { fileID } as unknown as Photo;
-        },
-    };
 }
 
 describe("CLI read helpers (issue #36 amendment, issue #52)", () => {
-    it("freshCollections refreshes first, then lists in enumeration order", async () => {
+    it("freshCollections reads the collection list alone, in enumeration order", async () => {
         // Enumeration order 2, 1, 3; a newest-first sort would be 3, 2, 1.
         const lib = new FakeLibrary(
             [collection(2, 200), collection(1, 300), collection(3, 100)],
@@ -114,7 +124,8 @@ describe("CLI read helpers (issue #36 amendment, issue #52)", () => {
         );
         const rows = await freshCollections(lib);
 
-        expect(lib.freshCalls).toBe(1);
+        expect(lib.freshCollectionsCalls).toBe(1);
+        expect(lib.freshCalls).toBe(0);
         expect(rows.map((c) => c.id)).toEqual([2, 1, 3]);
         // The projection's newest-first order is a different sequence, so this
         // is not accidentally that order.
@@ -125,18 +136,24 @@ describe("CLI read helpers (issue #36 amendment, issue #52)", () => {
         expect(rows.map((c) => c.id)).not.toEqual(newestFirst);
     });
 
-    it("freshFiles refreshes first, lists in enumeration order, keeps raw fields", async () => {
+    it("freshFiles with a collection ID reads that collection's files alone and keeps their order and raw fields", async () => {
-        // Enumeration order by id 10, 11, 12; creationTimes ascending, so a
+        // Given in the order 10, 11, 12; creationTimes ascending, so a
         // newest-first sort would reverse them.
         const files = [
             file(10, 1, 1_700_000_000_000_000),
             file(11, 1, 1_700_000_000_000_001),
             file(12, 1, 1_700_000_000_000_002),
+            file(20, 2, 1_700_000_000_000_003),
         ];
-        const lib = new FakeLibrary([collection(1, 100)], files);
+        const lib = new FakeLibrary(
+            [collection(1, 100), collection(2, 200)],
+            files,
+        );
 
         const rows = await freshFiles(lib, 1);
-        expect(lib.freshCalls).toBe(1);
+        expect(lib.freshCalls).toBe(0);
+        expect(lib.freshCollectionsCalls).toBe(1);
+        expect(lib.freshFilesCalls).toEqual([1]);
         expect(rows?.map((f) => f.id)).toEqual([10, 11, 12]);
 
         // Field values come from raw metadata: microsecond creationTime and the
@@ -166,30 +183,144 @@ describe("CLI read helpers (issue #36 amendment, issue #52)", () => {
         ]);
     });
 
+    // Without a collection ID, `files` lists every file in the account once
+    // (issue #211). File 11 is in collections 1 and 2; collection 2 is
+    // enumerated first, so 11 is listed once, with collection 2's record.
+    it("freshFiles without a collection ID lists every file once, from the first collection holding it", async () => {
+        const files = [
+            file(10, 1, 1_700_000_000_000_000),
+            file(11, 1, 1_700_000_000_000_001),
+            file(20, 2, 1_700_000_000_000_002),
+            file(11, 2, 1_700_000_000_000_001),
+        ];
+        const lib = new FakeLibrary(
+            [collection(2, 100), collection(1, 200)],
+            files,
+        );
+
+        const rows = await freshFiles(lib);
+        expect(lib.freshCalls).toBe(1);
+        expect(rows?.map((f) => [f.id, f.collectionID])).toEqual([
+            [20, 2],
+            [11, 2],
+            [10, 1],
+        ]);
+    });
+
     it("freshFiles returns undefined for an unknown collection", async () => {
         const lib = new FakeLibrary([collection(1, 100)], []);
         const rows = await freshFiles(lib, 999);
-        expect(lib.freshCalls).toBe(1);
+        expect(lib.freshCalls).toBe(0);
+        expect(lib.freshFilesCalls).toEqual([]);
         expect(rows).toBeUndefined();
     });
 
-    it("freshFile refreshes first, then resolves the photo and its raw record", async () => {
+    // Three collections, each holding one file.
-        const f = file(10, 1, 1_700_000_000_000_000);
+    const threeCollections = (): FakeLibrary =>
-        const lib = new FakeLibrary([collection(1, 100)], [f]);
+        new FakeLibrary(
-
+            [collection(1, 100), collection(2, 200), collection(3, 300)],
-        const resolved = await freshFile(lib, 10);
+            [
-        expect(lib.freshCalls).toBe(1);
+                file(10, 1, 1_700_000_000_000_000),
-        expect(resolved?.photo.fileID).toBe(10);
+                file(20, 2, 1_700_000_000_000_001),
-        expect(resolved?.file.metadata.title).toBe("file-10.jpg");
+                file(30, 3, 1_700_000_000_000_002),
-        expect(resolved?.file.metadata.creationTime).toBe(
+            ],
-            1_700_000_000_000_000,
         );
+
+    it("freshFile on an empty cache reads each collection's files in the server's order until one holds the file", async () => {
+        const lib = threeCollections();
+
+        const found = await freshFile(lib, 20);
+        expect(lib.freshCalls).toBe(0);
+        expect(lib.freshCollectionsCalls).toBe(1);
+        expect(lib.freshFilesCalls).toEqual([1, 2]);
+        expect(found?.metadata.title).toBe("file-20.jpg");
+        expect(found?.metadata.creationTime).toBe(1_700_000_000_000_001);
     });
 
-    it("freshFile returns undefined for an unknown file", async () => {
+    // The stand-in's cache holds what the server holds once `fresh()` has run.
-        const lib = new FakeLibrary([collection(1, 100)], []);
+    it("freshFile on a cache that holds the collections refreshes, then looks the file up in the cache", async () => {
-        const resolved = await freshFile(lib, 404);
+        const lib = threeCollections();
-        expect(lib.freshCalls).toBe(1);
+        await lib.fresh();
-        expect(resolved).toBeUndefined();
+
+        const found = await freshFile(lib, 30);
+        expect(lib.freshCalls).toBe(2);
+        expect(lib.freshCollectionsCalls).toBe(0);
+        expect(lib.freshFilesCalls).toEqual([]);
+        expect(found?.collectionID).toBe(3);
+    });
+
+    it("freshFile on an empty cache returns undefined for an unknown file, after reading every collection's files", async () => {
+        const lib = threeCollections();
+
+        const found = await freshFile(lib, 404);
+        expect(lib.freshCalls).toBe(0);
+        expect(lib.freshFilesCalls).toEqual([1, 2, 3]);
+        expect(found).toBeUndefined();
+    });
+
+    // The server lists collections 1, 2 and 3, and collection 3 was updated
+    // most recently. File 11 is in collections 1 and 2.
+    const fileInTwoCollections = (): FakeLibrary =>
+        new FakeLibrary(
+            [collection(1, 100), collection(2, 200), collection(3, 300)],
+            [
+                file(10, 1, 1_700_000_000_000_000),
+                file(11, 1, 1_700_000_000_000_001),
+                file(11, 2, 1_700_000_000_000_001),
+                file(20, 2, 1_700_000_000_000_002),
+                file(30, 3, 1_700_000_000_000_003),
+            ],
+        );
+
+    it("freshFilesByID on an empty cache reads the most recently updated collection's files first, until it has found every file", async () => {
+        const lib = fileInTwoCollections();
+
+        const found = await freshFilesByID(lib, [11, 20]);
+        expect(lib.freshCalls).toBe(0);
+        expect(lib.freshCollectionsCalls).toBe(1);
+        expect(lib.freshFilesCalls).toEqual([3, 2]);
+        expect(found.get(11)?.collection.id).toBe(2);
+        expect(found.get(11)?.file.collectionID).toBe(2);
+        expect(found.get(20)?.collection.id).toBe(2);
+    });
+
+    // Collection 1 was updated last, though collections 2 and 3 have higher
+    // IDs. File 11 is in collections 1 and 2.
+    it("freshFilesByID on an empty cache reads the most recently updated collection first, though its ID is the lowest", async () => {
+        const lib = new FakeLibrary(
+            [collection(1, 400), collection(2, 200), collection(3, 300)],
+            [
+                file(11, 1, 1_700_000_000_000_001),
+                file(11, 2, 1_700_000_000_000_001),
+            ],
+        );
+
+        const found = await freshFilesByID(lib, [11]);
+        expect(lib.freshFilesCalls).toEqual([1]);
+        expect(found.get(11)?.collection.id).toBe(1);
+        expect(found.get(11)?.file.collectionID).toBe(1);
+    });
+
+    // The stand-in's cache holds what the server holds once `fresh()` has run.
+    it("freshFilesByID on a cache that holds the collections refreshes, then finds each file in the most recently updated collection that holds it", async () => {
+        const lib = fileInTwoCollections();
+        await lib.fresh();
+
+        const found = await freshFilesByID(lib, [11, 404]);
+        expect(lib.freshCalls).toBe(2);
+        expect(lib.freshCollectionsCalls).toBe(0);
+        expect(lib.freshFilesCalls).toEqual([]);
+        expect(found.get(11)?.collection.id).toBe(2);
+        expect(found.get(11)?.file.collectionID).toBe(2);
+        expect(found.has(404)).toBe(false);
+    });
+
+    it("freshFilesByID on an empty cache reads every collection's files when a file is in none of them", async () => {
+        const lib = fileInTwoCollections();
+
+        const found = await freshFilesByID(lib, [10, 404]);
+        expect(lib.freshFilesCalls).toEqual([3, 2, 1]);
+        expect(found.get(10)?.collection.id).toBe(1);
+        expect(found.has(404)).toBe(false);
     });
 });

test/cli/run.test.ts

@@ -6,6 +6,7 @@ import { PassThrough } from "node:stream";
 import { describe, it, expect } from "vitest";
 
 import { ApiError } from "../../src/api/client.js";
+import { stderrLog } from "../../src/cli-log.js";
 import { run } from "../../src/cli-run.js";
 
 // A stream whose written text is kept in `text`; writes finish at once, so
@@ -23,7 +24,13 @@ const runToExit = async (
     const stdout = collector();
     const stderr = collector();
     const code = await new Promise<number>((resolve) => {
-        void run(command, stdout.stream, stderr.stream, resolve);
+        void run(
+            command,
+            stdout.stream,
+            stderr.stream,
+            stderrLog(stderr.stream, "info"),
+            resolve,
+        );
     });
     return { code, stdout: stdout.text(), stderr: stderr.text() };
 };
@@ -48,6 +55,78 @@ describe("run", () => {
         );
     });
 
+    // Node's `fetch` rejects every failure below HTTP with a TypeError that
+    // says only "fetch failed", and hangs the reason, with its errno, off
+    // `cause`. The printed line carries the reason, so a cron log tells a
+    // refused connection from a name that did not resolve.
+    it("prints the reason a fetch failed, from the error's cause", async () => {
+        const refused = new TypeError("fetch failed", {
+            cause: Object.assign(
+                new Error("connect ECONNREFUSED 1.2.3.4:443"),
+                { code: "ECONNREFUSED" },
+            ),
+        });
+        const result = await runToExit(Promise.reject(refused));
+        expect(result).toEqual({
+            code: 1,
+            stdout: "",
+            stderr: "quak: fetch failed: connect ECONNREFUSED 1.2.3.4:443\n",
+        });
+    });
+
+    // When the host has several addresses and every one refuses, Node's
+    // `fetch` gives as the cause an AggregateError with an empty message and
+    // one error per address. The printed line gives each address's reason.
+    it("prints the reason for each address a fetch could not reach", async () => {
+        const refusedAt = (address: string): Error =>
+            Object.assign(new Error(`connect ECONNREFUSED ${address}`), {
+                code: "ECONNREFUSED",
+            });
+        const refused = new TypeError("fetch failed", {
+            cause: Object.assign(
+                new AggregateError([
+                    refusedAt("2001:db8::1:443"),
+                    refusedAt("1.2.3.4:443"),
+                ]),
+                { code: "ECONNREFUSED" },
+            ),
+        });
+        const result = await runToExit(Promise.reject(refused));
+        expect(result).toEqual({
+            code: 1,
+            stdout: "",
+            stderr: "quak: fetch failed: connect ECONNREFUSED 2001:db8::1:443, connect ECONNREFUSED 1.2.3.4:443\n",
+        });
+    });
+
+    // An error that already quotes its cause's message is printed as it is.
+    it("does not print a cause's message twice", async () => {
+        const reset = new Error("read ECONNRESET");
+        const wrapped = new Error(`download: file 7: ${reset.message}`, {
+            cause: reset,
+        });
+        const result = await runToExit(Promise.reject(wrapped));
+        expect(result.stderr).toBe("quak: download: file 7: read ECONNRESET\n");
+    });
+
+    // OpenSSL ends its message for a failed TLS connection, such as one to a
+    // server that answers in plain HTTP, with a newline. The printed line is
+    // still one line.
+    it("prints a cause's message without the white space around it", async () => {
+        const wrongVersion = new TypeError("fetch failed", {
+            cause: Object.assign(
+                new Error(
+                    "C0B73A55A47F0000:error:0A00010B:SSL routines:ssl3_get_record:wrong version number:../deps/openssl/openssl/ssl/record/ssl3_record.c:354:\n",
+                ),
+                { code: "ERR_SSL_WRONG_VERSION_NUMBER" },
+            ),
+        });
+        const result = await runToExit(Promise.reject(wrongVersion));
+        expect(result.stderr).toBe(
+            "quak: fetch failed: C0B73A55A47F0000:error:0A00010B:SSL routines:ssl3_get_record:wrong version number:../deps/openssl/openssl/ssl/record/ssl3_record.c:354:\n",
+        );
+    });
+
     it("prints a thrown value that is not an Error", async () => {
         const result = await runToExit(Promise.reject("offline"));
         expect(result).toEqual({
@@ -57,6 +136,14 @@ describe("run", () => {
         });
     });
 
+    // A cause that is not an Error, such as a thrown string, is printed as a
+    // thrown value that is not an Error is.
+    it("prints a cause that is not an Error", async () => {
+        const wrapped = new Error("ML data", { cause: "offline" });
+        const result = await runToExit(Promise.reject(wrapped));
+        expect(result.stderr).toBe("quak: ML data: offline\n");
+    });
+
     it("on a 401 from the server says to run quak login, on one line, and exits 3", async () => {
         const result = await runToExit(
             Promise.reject(new ApiError("unauthorized", 401)),

test/clip-keywords-sunset.json

@@ -0,0 +1,109 @@
+{
+    "photo": "https://upload.wikimedia.org/wikipedia/commons/d/db/Sunset_off_the_Massachusetts_coast_-_NOAA.jpg",
+    "sha256": "be62f3289c9bf7b75af68cd6978021d54e8a531d5d4cc493f6e9fbf5e1ab74d3",
+    "embedding": [
+        -0.0021123015, -0.04437615, -0.062354308, 0.006249992, 0.022141185,
+        0.011159019, 0.01227392, -0.00030532264, 0.03186437, 0.09196922,
+        0.039111234, -0.037084445, -0.032962628, -0.019820206, -0.013141825,
+        0.0047183544, 0.017137334, 0.046581306, 0.0047622235, 0.04982521,
+        0.023128154, 0.032080866, 0.037709303, 0.019241406, 0.0032100384,
+        -0.014275843, 0.049337693, 0.025953151, 0.014263995, -0.0062328726,
+        -0.040504098, -0.015083303, -0.008123875, -0.006233639, -0.05352683,
+        -0.0048083956, 0.0763486, -0.013155067, 0.025114346, 0.022016674,
+        0.0001588023, -0.010341572, -0.0037518279, -0.019181008, 0.04549337,
+        -0.0010725886, 0.004636866, 0.017177915, -0.0117317885, 0.0026097358,
+        0.030738998, 0.013158572, -0.08856403, -0.0121391015, 0.011477229,
+        -0.0033104012, 0.035524756, -0.018607879, -0.0071739843, -0.031906743,
+        0.0056713386, -0.0044195866, 0.00292471, 0.00061686034, -0.043075223,
+        0.09040427, 0.001522537, -0.011445652, 0.009609886, -0.0053201183,
+        -0.0057452377, 0.00972853, -0.0024397348, -0.021255083, 0.015893811,
+        -0.006020548, -0.09428023, 0.014277583, -0.017975299, -0.011878315,
+        0.011825521, 0.00014203975, -0.0020437292, -0.05305343, -0.024840152,
+        -0.011336872, -0.002796541, -0.00036171873, 0.004530499, 0.044486605,
+        0.021602718, -0.01292857, 0.024530916, 0.019559948, -0.039928272,
+        -0.0681174, 0.049101, 0.02461532, 0.0365531, -0.04070358, -0.011011939,
+        -0.0027188526, -0.020370876, 0.012904856, 0.043157287, -0.051658224,
+        -0.3726012, 0.019549074, -0.0499252, -0.04800559, -0.011493859,
+        0.02893256, 0.060341954, 0.0013929688, -0.051283866, -0.024286803,
+        0.044124287, -0.005995806, -0.062817656, 0.007369614, -0.021470634,
+        -0.028147545, 0.00411659, 0.04234773, 0.03787647, 0.008579682,
+        -0.038568925, -0.027498025, -0.028416378, 0.0022012168, 0.010906191,
+        -0.013745787, 0.018267838, 0.013531097, -0.061559845, 0.004682517,
+        -0.005993303, 0.0028113858, -0.0028286583, 0.0026029332, -0.06693403,
+        -0.0072381413, -0.02419584, 0.0037009937, -0.0011296495, -0.030310456,
+        0.0005999609, 0.009945354, 0.024915686, 0.038672045, 0.023009432,
+        -0.05093051, -0.09101409, -0.06686167, -0.06211481, -0.022600474,
+        0.0024902367, -0.0067171026, -0.016769778, -0.0032803628, 0.008623083,
+        -0.0016110836, 0.014925073, 0.033811048, 0.012829449, -0.052575592,
+        0.03728281, -0.0051201633, 0.021238064, -0.031086605, -0.0043402985,
+        0.25054494, -0.028396713, -0.010725523, -0.023445267, 0.021751683,
+        0.003130971, 0.012270548, -0.014836475, 0.014466885, 0.0021478906,
+        -0.088153616, 0.015356315, 0.039639276, -0.040283255, 0.014923924,
+        -0.029303031, -0.004475201, 0.047299225, -0.06726505, -0.012491676,
+        -0.002080582, 0.03506341, 0.04146718, 0.0074114986, -0.009582633,
+        0.006623749, -0.05454898, -0.0034387247, -0.014780821, 0.03698328,
+        -0.034441486, 0.22032379, -0.021792699, 0.008001907, 0.0341019,
+        0.0025784625, -0.0071689896, -0.014151225, -0.050547987, -0.030372301,
+        -0.03288388, -0.042987447, -0.0033656165, 0.021502906, -0.0030374376,
+        -0.024413, -0.03506603, 0.030891743, 0.0069994032, 0.004887366,
+        0.030707076, 0.0065348223, 0.0008240555, 0.016809713, -0.024151647,
+        -0.0040458064, 0.044567548, 0.03908212, -0.061782435, 0.0026002831,
+        0.02003242, -0.0115451, -0.045135964, -0.0663542, 0.005240975,
+        0.0010777109, -0.009276002, -0.011919081, 0.027654119, -0.013634551,
+        0.0129154315, -0.013195512, 0.040571272, -0.099290505, -0.04656693,
+        -0.20979854, 0.04181004, -0.06769166, -0.04121946, 0.018260444,
+        0.005617506, -0.15694222, 0.032472793, 0.014189598, 0.008345103,
+        -0.041118417, 0.0074527003, -0.011494104, 0.004906474, -0.0027100458,
+        0.0009994594, -0.041061398, -0.045274835, 0.015187793, 0.034275036,
+        -0.02813289, 0.02098019, -0.015043198, 0.03716667, 0.013542642,
+        -0.008104835, 0.014965486, -0.027978558, 0.021163663, -0.006942737,
+        -0.034969814, -0.038961593, 0.016802894, -0.012318175, -0.047821593,
+        -0.01933216, 0.0064432374, 0.0322358, -0.020437784, 0.02659447,
+        -0.03022022, -0.019443465, -0.094178624, -0.017009107, 0.03860671,
+        -0.00023695534, -0.033089854, -0.014677462, 0.012356399, 0.018040499,
+        -0.19360113, 0.011710817, -0.019871691, 0.020124774, 0.024948105,
+        -0.024573864, -0.028349072, -0.041731454, 0.032646254, 0.015098165,
+        0.0018447012, -0.01129152, -0.02481687, 0.036048, 0.20797811,
+        0.04317757, -0.017239755, 0.033431605, -0.011384422, 0.0099174455,
+        -0.19739223, -0.008901062, -0.056426458, 0.014591864, 0.0044474266,
+        0.008209326, -0.012241819, 0.042553645, -0.021552453, 0.008611734,
+        0.048944127, -0.013872049, 0.019179989, 0.008183264, -0.053223096,
+        -0.027327595, -0.0033542586, -0.012353858, -0.010941209, 0.010212546,
+        0.029714134, -0.011385593, -0.0013529479, 0.014505385, 0.01148663,
+        0.012613636, -0.0074430504, -0.014008101, -0.028146038, -0.042778917,
+        0.02143165, 0.016812252, -0.06286215, 0.02085532, -0.035128277,
+        0.0241282, 0.01397908, -0.034992814, 0.013153766, 0.0068236147,
+        0.013594184, -0.06859393, 0.051849406, 0.029675119, -0.0037699796,
+        -0.00013216575, 0.02916647, 0.031859048, -0.015006051, 0.0001439966,
+        0.0026584554, -0.0046948595, 0.039754897, 0.034873154, 0.0012870439,
+        -0.011516082, -0.074089095, 0.019241294, 0.00076195505, 0.0027334464,
+        -0.036206458, -0.0011109262, -0.048838835, -0.00204685, 0.01179991,
+        0.0068136845, 0.009852495, 0.017308988, 0.03159545, 0.058803353,
+        0.038116634, 0.008836143, -0.010460637, -0.010994099, -0.0012926942,
+        -0.048370842, 0.037696566, -0.08093239, -0.0041242186, -0.005866373,
+        0.02048607, -0.12549639, 0.011705739, -0.0021425558, 0.018078592,
+        -0.038228087, 0.004245971, -0.11560507, 0.01381203, -0.02734893,
+        0.029595908, 0.101082794, -0.042842254, -0.08397301, -0.1546237,
+        -0.037624564, 0.0069606556, -0.008020479, 0.0043268185, 0.016504597,
+        0.044554908, -0.05240209, 0.020519335, -0.050994243, -0.019861093,
+        0.022066997, -0.0188911, 0.012919696, -0.022872692, -0.012961374,
+        -0.020071112, 0.0074553066, 0.06402014, 0.04065211, 0.014139608,
+        0.06221546, -0.02574805, 0.010114545, 0.020619567, 0.032264773,
+        -0.009148828, 0.022849955, -0.016593235, -0.032456633, -0.006737303,
+        -0.0037493357, -0.065912865, -0.0024181998, -0.0037048983, -0.019304488,
+        0.009085037, 0.057529982, -0.0378338, 0.01792042, 0.01885012,
+        -0.0043600523, 0.017382368, -0.027792772, 0.006749118, -0.0053297766,
+        -0.011628587, 0.015736576, 0.024801968, 0.011543913, -0.01159873,
+        -0.000759976, 0.042183932, 0.05764386, -0.06422416, 0.010577374,
+        -0.02261249, 0.02282793, -0.05141075, -0.11287078, -0.020670144,
+        -0.020953743, 0.030885734, -0.012597732, -0.121472664, 0.028447151,
+        -0.0415664, -0.010061708, 0.06441338, 0.0271207, -0.0016693748,
+        -0.0045694243, 0.020342957, 0.030528478, 0.007129517, -0.0029600926,
+        -0.007061397, 0.06036486, -0.004736018, -0.0090786135, -0.07601116,
+        -0.039556272, -0.051269546, -0.019473685, 0.029858151, 0.028464556,
+        0.012424476, 0.013742254, 0.008742927, 0.006065751, -0.009892663,
+        0.07699999, -0.003443197, 0.0027863425, 0.029197995, 0.0211013,
+        0.01098379, 0.016684106, -0.028917195, 0.008122037, 0.0265241,
+        -0.04461223
+    ]
+}

test/clip-keywords.test.ts

@@ -0,0 +1,129 @@
+// `clipKeywords`: the keywords quak writes for a file in place of its CLIP
+// embedding.
+//
+// Ente's ML data for a file holds a CLIP embedding, 512 numbers its image
+// model gave the photo. Ente's photos app puts a file in a category of its
+// Discover section when the cosine similarity of that embedding and the text
+// embedding of the category's query is at least the category's minimum score,
+// and keeps videos out of some categories. `clipKeywords` applies that rule
+// and returns the titles of the categories a file falls in, highest score
+// first; `quak backup` and `quak backup-metadata` write them as `keywords`.
+
+import { readFileSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+
+import { DISCOVER_CATEGORIES } from "../src/clip-keyword-vectors.js";
+import { clipKeywords } from "../src/clip-keywords.js";
+
+// 512 numbers: the ones given, then zeros.
+const vector = (...start: number[]): number[] => [
+    ...start,
+    ...new Array<number>(512 - start.length).fill(0),
+];
+
+const withEmbedding = (embedding: unknown) => ({
+    face: { faces: [] },
+    clip: { embedding },
+});
+
+// Two made-up categories, each with a text embedding along one axis. The
+// embedding [3, 4] has a cosine similarity of 3/5 with "Across" and 4/5 with
+// "Up". Videos are kept out of "Across".
+const ACROSS = {
+    title: "Across",
+    query: "across",
+    minScore: 0.6,
+    showVideo: false,
+    textEmbedding: vector(1),
+};
+const UP = {
+    title: "Up",
+    query: "up",
+    minScore: 0.5,
+    showVideo: true,
+    textEmbedding: vector(0, 1),
+};
+
+describe("clipKeywords", () => {
+    it("gives each category whose minimum score the similarity reaches, highest score first", () => {
+        expect(
+            clipKeywords(withEmbedding(vector(3, 4)), false, [ACROSS, UP]),
+        ).toEqual(["Up", "Across"]);
+    });
+
+    it("leaves out a category when the similarity is just below its minimum score", () => {
+        const stricter = { ...ACROSS, minScore: 0.6 + 1e-9 };
+
+        expect(
+            clipKeywords(withEmbedding(vector(3, 4)), false, [stricter, UP]),
+        ).toEqual(["Up"]);
+    });
+
+    it("keeps a video out of a category that leaves out videos", () => {
+        expect(
+            clipKeywords(withEmbedding(vector(3, 4)), true, [ACROSS, UP]),
+        ).toEqual(["Up"]);
+    });
+
+    it("gives an empty list for an embedding that falls in no category", () => {
+        expect(
+            clipKeywords(withEmbedding(vector(0, 0, 1)), false, [ACROSS, UP]),
+        ).toEqual([]);
+    });
+
+    it.each([
+        ["no CLIP embedding", { face: { faces: [] } }],
+        ["a CLIP part that is not an object", { clip: null }],
+        ["a CLIP part without an embedding", { clip: {} }],
+        ["an embedding of 511 numbers", withEmbedding(vector(3, 4).slice(1))],
+        ["an embedding with NaN in it", withEmbedding(vector(3, NaN))],
+        ["an embedding with Infinity in it", withEmbedding(vector(Infinity))],
+        ["an embedding of strings", withEmbedding(vector(3, 4).map(String))],
+        ["an embedding of zeros", withEmbedding(vector())],
+    ])("gives no keywords for ML data with %s", (_, mlData) => {
+        expect(clipKeywords(mlData, false, [ACROSS, UP])).toBeUndefined();
+    });
+});
+
+// The CLIP embedding Ente's image model gives a public-domain NOAA photo of a
+// sunset, made by bin/clip-keyword-vectors from the photo at `photo`.
+const SUNSET: { photo: string; sha256: string; embedding: number[] } =
+    JSON.parse(
+        readFileSync(
+            new URL("clip-keywords-sunset.json", import.meta.url),
+            "utf-8",
+        ),
+    );
+
+describe("Ente's Discover categories", () => {
+    it("are the 16 of Ente's photos app, each with a text embedding of norm 1", () => {
+        expect(DISCOVER_CATEGORIES.map((c) => c.title)).toEqual([
+            "Identity",
+            "Screenshots",
+            "QR Codes",
+            "Receipts",
+            "Notes",
+            "Memes",
+            "Visiting Cards",
+            "Babies",
+            "Pets",
+            "Selfies",
+            "Wallpapers",
+            "Food",
+            "Celebrations",
+            "Sunset",
+            "Hills",
+            "Greenery",
+        ]);
+        for (const category of DISCOVER_CATEGORIES) {
+            expect(category.textEmbedding).toHaveLength(512);
+            expect(Math.hypot(...category.textEmbedding)).toBeCloseTo(1, 5);
+        }
+    });
+
+    it("give a photo of a sunset the keyword Sunset and no other", () => {
+        expect(
+            clipKeywords({ clip: { embedding: SUNSET.embedding } }, false),
+        ).toEqual(["Sunset"]);
+    });
+});

test/download/download.test.ts

@@ -74,7 +74,11 @@ import {
 } from "vitest";
 import { init, toBase64, STREAM_CHUNK_SIZE } from "../../src/crypto/index.js";
 import { ApiClient } from "../../src/api/client.js";
-import { ApiError, TruncatedStreamError } from "../../src/errors.js";
+import {
+    ApiError,
+    describeError,
+    TruncatedStreamError,
+} from "../../src/errors.js";
 import type { RetryOptions } from "../../src/retry.js";
 import {
     downloadFile,
@@ -654,6 +658,26 @@ describe("downloadFile", () => {
         expect(readdirSync(parent)).toEqual(["cwd"]);
     });
 
+    // A file system refuses a file name over 255 bytes.
+    it("cuts a title too long for a file name short, keeping its extension", async () => {
+        const plaintext = new Uint8Array([1, 2, 3]);
+        const key = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+        const { header, ciphertext } = encryptFileBody(plaintext, key);
+        const thumbPush =
+            sodium.crypto_secretstream_xchacha20poly1305_init_push(key);
+        const file = buildMockEnteFile(key, header, thumbPush.header);
+        file.metadata.title = `${"t".repeat(296)}.jpg`;
+        const dir = mkdtempSync(join(testDir, "long-title-"));
+
+        const api = new ApiClient({ fetch: mockFetchForBody(ciphertext) });
+        const result = await inDirectory(dir, () => downloadFile(api, file));
+
+        const name = `${"t".repeat(251)}.jpg`;
+        expect(Buffer.byteLength(name)).toBe(255);
+        expect(result.path).toBe(name);
+        expect(readdirSync(dir)).toEqual([name]);
+    });
+
     it("uses an explicit outPath verbatim, even one with ..", async () => {
         // The caller is trusted: its path is not sanitized.
         const { api, file } = fixtureFor(
@@ -747,6 +771,28 @@ describe("downloadThumbnail", () => {
         expect(result.path).toBe("thumb__etc_passwd");
         expect(readdirSync(dir)).toEqual(["thumb__etc_passwd"]);
     });
+
+    it("leaves room for thumb_ when it cuts a title too long for a file name short", async () => {
+        const plaintext = new Uint8Array([0xff, 0xd8, 0xff, 0xe0]);
+        const key = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+        const filePush =
+            sodium.crypto_secretstream_xchacha20poly1305_init_push(key);
+        const { header: thumbHeader, ciphertext: thumbCipher } =
+            encryptFileBody(plaintext, key);
+        const file = buildMockEnteFile(key, filePush.header, thumbHeader);
+        file.metadata.title = `${"t".repeat(296)}.jpg`;
+        const dir = mkdtempSync(join(testDir, "long-thumb-title-"));
+
+        const api = new ApiClient({ fetch: mockFetchForBody(thumbCipher) });
+        const result = await inDirectory(dir, () =>
+            downloadThumbnail(api, file),
+        );
+
+        const name = `thumb_${"t".repeat(245)}.jpg`;
+        expect(Buffer.byteLength(name)).toBe(255);
+        expect(result.path).toBe(name);
+        expect(readdirSync(dir)).toEqual([name]);
+    });
 });
 
 // ---------------------------------------------------------------------------
@@ -834,6 +880,11 @@ describe.each(entryPoints)(
             expect(((err as Error).cause as Error).message).toMatch(
                 /authentication failed/i,
             );
+            // As quak prints it and records it in `failures.json`, the error
+            // states the authentication failure once, from its cause.
+            expect(describeError(err)).toMatch(
+                /^download: stream truncated: response body ended with \d+ trailing bytes \(transfer stopped mid-chunk, or the data is corrupt\): secretstream chunk authentication failed$/,
+            );
 
             // And, as with every other failure, the destination is untouched
             // and no staged temp file survives.
@@ -1872,6 +1923,53 @@ describe("downloadFile live photos", () => {
         ]);
     });
 
+    // A file system refuses a file name over 255 bytes. Each name is cut
+    // short once its own extension is in it.
+    const imageName = `${"t".repeat(250)}.heic`;
+    const videoName = `${"t".repeat(251)}.mov`;
+
+    // The title fits, but ".heic" is one byte longer than ".jpg".
+    it("cuts the image's name short for a 255-byte title ending in .jpg when no outPath is given", async () => {
+        const title = `${"t".repeat(251)}.jpg`;
+        const t = setup(livePhotoZip(), { ...livePhoto, title });
+
+        const result = await inDirectory(t.dir, () =>
+            downloadFile(t.api, t.file),
+        );
+
+        expect(Buffer.byteLength(title)).toBe(255);
+        expect(Buffer.byteLength(imageName)).toBe(255);
+        expect(Buffer.byteLength(videoName)).toBe(255);
+        expect(result.path).toBe(imageName);
+        expect(result.videoPath).toBe(videoName);
+        expect(readdirSync(t.dir).sort()).toEqual([imageName, videoName]);
+    });
+
+    it("cuts the names of the image and the video short for a 300-byte title with no extension when no outPath is given", async () => {
+        const t = setup(livePhotoZip(), {
+            ...livePhoto,
+            title: "t".repeat(300),
+        });
+
+        const result = await inDirectory(t.dir, () =>
+            downloadFile(t.api, t.file),
+        );
+
+        expect(result.path).toBe(imageName);
+        expect(result.videoPath).toBe(videoName);
+        expect(readdirSync(t.dir).sort()).toEqual([imageName, videoName]);
+    });
+
+    // The caller's path is used as is; only the extension is each part's own.
+    it("keeps an outPath too long for a file name as given", async () => {
+        const t = setup(livePhotoZip(), livePhoto);
+        const outPath = join(t.dir, `${"t".repeat(251)}.jpg`);
+
+        await expect(downloadFile(t.api, t.file, outPath)).rejects.toThrow(
+            /ENAMETOOLONG/,
+        );
+    });
+
     it("gives each part its own extension from the ZIP, letters and digits only", async () => {
         const zip = livePhotoZip({ "image.JPG": IMAGE, "video.m-4v": VIDEO });
         const t = setup(zip, livePhoto);

test/filename/filename.test.ts

@@ -14,7 +14,13 @@
 
 import { describe, expect, it } from "vitest";
 
-import { safeExtension, sanitizeFileName } from "../../src/filename.js";
+import {
+    defaultFileName,
+    safeExtension,
+    sanitizeFileName,
+    shortenKeepingExtension,
+    shortenToBytes,
+} from "../../src/filename.js";
 
 const FALLBACK = "file-42";
 
@@ -90,4 +96,133 @@ describe("safeExtension", () => {
         expect(safeExtension("x.jp g")).toBe(".bin");
         expect(safeExtension("x.jpg\0")).toBe(".bin");
     });
+
+    it("keeps an extension of 16 letters and digits, and uses .bin for a longer one", () => {
+        expect(safeExtension(`x.${"e".repeat(16)}`)).toBe(`.${"e".repeat(16)}`);
+        expect(safeExtension(`x.${"e".repeat(17)}`)).toBe(".bin");
+        expect(safeExtension(`b.${"e".repeat(300)}`)).toBe(".bin");
+    });
+});
+
+describe("shortenToBytes", () => {
+    it("returns a name that fits unchanged", () => {
+        expect(shortenToBytes("beach", 5)).toBe("beach");
+        expect(shortenToBytes("café", 5)).toBe("café");
+        expect(shortenToBytes("", 0)).toBe("");
+    });
+
+    it("cuts a name to the number of bytes given", () => {
+        expect(shortenToBytes("L".repeat(300), 255)).toBe("L".repeat(255));
+    });
+
+    // In UTF-8 "é" takes two bytes and an emoji four, which a JavaScript
+    // string holds as two halves.
+    it("cuts between two characters, never inside one", () => {
+        expect(shortenToBytes("ééé", 5)).toBe("éé");
+        expect(shortenToBytes("a\u{1F600}b", 4)).toBe("a");
+        expect(shortenToBytes("a\u{1F600}b", 5)).toBe("a\u{1F600}");
+        expect(Buffer.byteLength(shortenToBytes("é".repeat(200), 255))).toBe(
+            254,
+        );
+    });
+});
+
+describe("shortenKeepingExtension", () => {
+    it("returns a name that fits unchanged", () => {
+        expect(shortenKeepingExtension("beach.jpg", 9)).toBe("beach.jpg");
+        expect(shortenKeepingExtension("beach", 5)).toBe("beach");
+    });
+
+    it("cuts the part before the extension short and keeps the extension", () => {
+        expect(shortenKeepingExtension(`${"t".repeat(296)}.jpg`, 255)).toBe(
+            `${"t".repeat(251)}.jpg`,
+        );
+        expect(shortenKeepingExtension("é".repeat(150), 255)).toBe(
+            "é".repeat(127),
+        );
+    });
+
+    // A name cut down to its extension would start with a dot, and so be
+    // hidden.
+    it("keeps the first character before the extension, cutting the extension short to leave room for it", () => {
+        expect(shortenKeepingExtension(`b.${"e".repeat(300)}`, 255)).toBe(
+            `b.${"e".repeat(253)}`,
+        );
+        expect(shortenKeepingExtension(`ab.${"e".repeat(300)}`, 255)).toBe(
+            `a.${"e".repeat(253)}`,
+        );
+        expect(shortenKeepingExtension(`é.${"e".repeat(300)}`, 255)).toBe(
+            `é.${"e".repeat(252)}`,
+        );
+        // "€" takes three bytes, so the extension is cut to 253 and the
+        // part before it keeps the two bytes left over, for the "a".
+        expect(shortenKeepingExtension(`a.${"€".repeat(90)}`, 255)).toBe(
+            `a.${"€".repeat(84)}`,
+        );
+    });
+
+    it("puts `insert` right before the extension and leaves room for it", () => {
+        expect(shortenKeepingExtension("beach.jpg", 255, " (7)")).toBe(
+            "beach (7).jpg",
+        );
+        expect(
+            shortenKeepingExtension(`${"t".repeat(296)}.jpg`, 255, " (7)"),
+        ).toBe(`${"t".repeat(247)} (7).jpg`);
+        expect(
+            shortenKeepingExtension(`b.${"e".repeat(300)}`, 255, " (7)"),
+        ).toBe(`b (7).${"e".repeat(249)}`);
+    });
+});
+
+describe("defaultFileName", () => {
+    it("is the title when it is safe and fits", () => {
+        expect(defaultFileName("IMG_0001.HEIC", 42)).toBe("IMG_0001.HEIC");
+    });
+
+    it("replaces unsafe characters, and is file-<id> for an empty title", () => {
+        expect(defaultFileName("../x.jpg", 42)).toBe("__x.jpg");
+        expect(defaultFileName("", 42)).toBe("file-42");
+    });
+
+    it("cuts a title over 255 bytes short, keeping its extension", () => {
+        expect(defaultFileName(`${"t".repeat(296)}.jpg`, 42)).toBe(
+            `${"t".repeat(251)}.jpg`,
+        );
+        expect(defaultFileName(`b.${"e".repeat(300)}`, 42)).toBe(
+            `b.${"e".repeat(253)}`,
+        );
+    });
+
+    it("puts `prefix` before the title and leaves room for it", () => {
+        expect(defaultFileName("beach.jpg", 42, { prefix: "thumb_" })).toBe(
+            "thumb_beach.jpg",
+        );
+        expect(
+            defaultFileName(`${"t".repeat(296)}.jpg`, 42, { prefix: "thumb_" }),
+        ).toBe(`thumb_${"t".repeat(245)}.jpg`);
+    });
+
+    // A live photo's image and video are each named with their own
+    // extension, and the name is cut short once that extension is in it.
+    it("puts `ext` in place of the title's extension before cutting the name short", () => {
+        expect(defaultFileName("IMG_0001.HEIC", 42, { ext: ".mov" })).toBe(
+            "IMG_0001.mov",
+        );
+        expect(defaultFileName("", 42, { ext: ".mov" })).toBe("file-42.mov");
+        expect(
+            defaultFileName(`${"t".repeat(251)}.jpg`, 42, { ext: ".heic" }),
+        ).toBe(`${"t".repeat(250)}.heic`);
+        expect(defaultFileName("t".repeat(300), 42, { ext: ".heic" })).toBe(
+            `${"t".repeat(250)}.heic`,
+        );
+    });
+
+    // Cutting `CONSOLE` or `NULL` short before a long extension leaves `CON`
+    // or `NUL`, so the name gets the `_` `sanitizeFileName` gives a device
+    // name, and the part before the extension gives up a byte for it.
+    it("never returns a Windows device name, even once cut short", () => {
+        const ext = `.${"e".repeat(251)}`;
+        expect(defaultFileName(`CONSOLE${ext}`, 42)).toBe(`_CO${ext}`);
+        expect(defaultFileName(`NULL${ext}`, 42)).toBe(`_NU${ext}`);
+    });
 });

test/library/content-library.test.ts

@@ -253,6 +253,12 @@ describe("Library content wiring", () => {
         await expect(
             lib.thumbnails.ensure({ fileIDs: [1], priority: "visible" }),
         ).rejects.toThrow(/content cache/i);
+        await expect(lib.originalOf(file(1, 1))).rejects.toThrow(
+            /content cache/i,
+        );
+        await expect(lib.thumbnailOf(file(1, 1))).rejects.toThrow(
+            /content cache/i,
+        );
         await lib.close();
     });
 });

test/library/content.test.ts

@@ -375,6 +375,25 @@ describe("ContentCache.original / thumbnail", () => {
         await cache.open();
         await expect(cache.original(999)).rejects.toThrow(/unknown file/i);
     });
+
+    // `getFile` knows no file here, so the cache can fetch only the file it is
+    // given.
+    it("originalOf and thumbnailOf fetch and cache the file they are given", async () => {
+        const { cache, source } = buildCache({ files: [] });
+        await cache.open();
+
+        const original = await cache.originalOf(file(5));
+        const thumbnail = await cache.thumbnailOf(file(5));
+
+        expect(source.originalCalls).toEqual([5]);
+        expect(source.thumbnailCalls).toEqual([5]);
+        expect(original.path).toBe(join(cacheDir, "originals", "5.jpg"));
+        expect(thumbnail.path).toBe(join(cacheDir, "thumbnails", "5.jpg"));
+        expect(cache.pathsFor(5)).toEqual({
+            originalPath: original.path,
+            thumbnailPath: thumbnail.path,
+        });
+    });
 });
 
 describe("ContentCache.ensureThumbnails", () => {

test/library/fresh.test.ts

@@ -14,6 +14,9 @@
  *     three.
  *  3. A refresh that fails rejects the fresh read (currency was unavailable),
  *     while the default reads stay silent and keep serving the last good copy.
+ *  4. `freshCollections()` reads the collection list alone, with one request
+ *     and no collection's files, and stores nothing, so the next refresh still
+ *     fetches the files of every collection (issue #210).
  *
  * The client is the same metadata-only mock the background-refresh tests use:
  * no crypto, no network, scripted pages, and a record of each call. A long
@@ -270,3 +273,70 @@ describe("Library.fresh", () => {
         }
     });
 });
+
+describe("Library.freshCollections", () => {
+    let dir: string;
+    let cacheDirectory: string;
+
+    beforeEach(() => {
+        dir = mkdtempSync(join(tmpdir(), "quak-fresh-collections-"));
+        cacheDirectory = join(dir, "cache");
+    });
+
+    afterEach(() => {
+        rmSync(dir, { recursive: true, force: true });
+    });
+
+    // A refresh fetches a collection's files only when the collection is new
+    // or its updationTime has advanced past the stored copy's. Had the
+    // collection list been stored, the next refresh would take every
+    // collection for one it already holds the files of, and fetch none.
+    it("asks for the collection list alone and stores nothing", async () => {
+        const client = new MockClient();
+        const page = {
+            collections: [collection(2, 100), collection(1, 110)],
+            deleted: [],
+            cursor: 110,
+        };
+        client.collectionsQueue.push(page, page);
+        client.filesFor(1, {
+            files: [file(1001, 1, 90)],
+            deleted: [],
+            cursor: 90,
+        });
+        client.filesFor(2, {
+            files: [file(2001, 2, 95)],
+            deleted: [],
+            cursor: 95,
+        });
+
+        const lib = await Library.open({
+            client,
+            cacheDirectory,
+            refreshOnOpen: false,
+            refreshIntervalSeconds: SLOW_INTERVAL,
+        });
+        try {
+            // One request, the whole list in the server's order, and no
+            // collection's files.
+            const collections = await lib.freshCollections();
+            expect(collections.map((c) => c.id)).toEqual([2, 1]);
+            expect(collections.map((c) => c.name)).toEqual([
+                "album-2",
+                "album-1",
+            ]);
+            expect(client.collectionsSinceTimes).toEqual([0]);
+            expect(client.filesCalls).toEqual([]);
+            expect(lib.listCollections()).toEqual([]);
+
+            // The next refresh still asks from the beginning and fetches the
+            // files of both collections.
+            const reads = await lib.fresh();
+            expect(client.collectionsSinceTimes).toEqual([0, 0]);
+            expect(reads.photos.byID({ fileID: 1001 })?.fileID).toBe(1001);
+            expect(reads.photos.byID({ fileID: 2001 })?.fileID).toBe(2001);
+        } finally {
+            await lib.close();
+        }
+    });
+});

test/library/library.test.ts

@@ -26,6 +26,9 @@
  *    opening.
  * 8. A save failure that leaves RAM ahead of disk keeps `status().lastError`
  *    set and keeps retrying the write; a later empty refresh does not clear it.
+ * 9. With `refreshOnOpen: false`, `open()` starts no refresh at all, and a
+ *    refresh reports through `onProgress` each collection whose files it
+ *    fetched.
  *
  * The client is a mock: no crypto, no network. It serves scripted pages and
  * records the `sinceTime` each call carried so cursor threading is provable.
@@ -581,6 +584,107 @@ describe("Library.open and background refresh", () => {
         }
     });
 
+    // A caller that asks for each refresh it needs, as the CLI's read commands
+    // do, opens without one: on an empty cache the refresh `open()` would
+    // await fetches the files of every collection, which `quak collections`
+    // never needs (issue #210).
+    it("starts no refresh as it opens when refreshOnOpen is false", async () => {
+        const client = new MockClient();
+        client.collectionsQueue.push({
+            collections: [collection(1, 100)],
+            deleted: [],
+            cursor: 100,
+        });
+
+        const lib = await Library.open({
+            client,
+            cacheDirectory,
+            refreshOnOpen: false,
+            refreshIntervalSeconds: Infinity,
+        });
+        try {
+            expect(client.collectionsSinceTimes).toEqual([]);
+            expect(lib.listCollections()).toEqual([]);
+            expect(lib.status().lastRefreshAt).toBeUndefined();
+
+            // The refresh comes when the caller asks for it.
+            await lib.fresh();
+            expect(client.collectionsSinceTimes).toEqual([0]);
+            expect(lib.listCollections().map((c) => c.id)).toEqual([1]);
+        } finally {
+            await lib.close();
+        }
+    });
+
+    // A refresh fetches the files of each collection that changed, one
+    // collection after another, and stores nothing until it has them all. On
+    // a large account that takes a while, so it reports each collection whose
+    // files it has fetched, and how many it will fetch in all (issue #210).
+    it("reports each collection whose files a refresh fetched", async () => {
+        const events: RefreshEvent[] = [];
+        const client = new MockClient();
+        client.collectionsQueue.push({
+            collections: [
+                collection(1, 100),
+                collection(2, 100),
+                collection(3, 100),
+            ],
+            deleted: [],
+            cursor: 100,
+        });
+
+        const lib = await Library.open({
+            client,
+            cacheDirectory,
+            refreshIntervalSeconds: Infinity,
+            onProgress: (e) => events.push(e),
+        });
+        try {
+            expect(events).toEqual([
+                { operation: "refresh", status: "started" },
+                {
+                    operation: "refresh",
+                    status: "progress",
+                    fetched: 1,
+                    total: 3,
+                },
+                {
+                    operation: "refresh",
+                    status: "progress",
+                    fetched: 2,
+                    total: 3,
+                },
+                {
+                    operation: "refresh",
+                    status: "progress",
+                    fetched: 3,
+                    total: 3,
+                },
+                { operation: "refresh", status: "done" },
+            ]);
+
+            // Only collection 2 changed since, so the next refresh fetches
+            // its files alone and counts one.
+            events.length = 0;
+            client.collectionsQueue.push({
+                collections: [collection(2, 200)],
+                deleted: [],
+                cursor: 200,
+            });
+            await lib.fresh();
+            expect(events.filter((e) => e.status === "progress")).toEqual([
+                {
+                    operation: "refresh",
+                    status: "progress",
+                    fetched: 1,
+                    total: 1,
+                },
+            ]);
+        } finally {
+            await lib.close();
+        }
+    });
+
     it("keeps a save failure visible until a save actually succeeds", async () => {
         const saveSpy = vi
             .spyOn(MetadataStore.prototype, "save")

test/library/mldata.test.ts

@@ -12,9 +12,11 @@
  *
  *   2. `Library` wiring: after each refresh the library fetches ML data through
  *      the metadata pool for every known file not yet cached, is incremental on
- *      later refreshes, and refetches a file whose `updationTime` advanced.
+ *      later refreshes, and refetches a file whose `updationTime` advanced. A
- *      Opening a cache directory written by another account starts empty,
+ *      file whose ML data did not decode is reported with the reason, which
- *      its ML data included (issue #104).
+ *      stays listed until the next pass ends, and asked for again. Opening a
+ *      cache directory written by another account starts empty, its ML data
+ *      included (issue #104).
  *
  * Embedding values are chosen to be exactly representable as float32 so the
  * round-trip through `clip.f32` compares equal.
@@ -26,7 +28,7 @@ import { tmpdir } from "node:os";
 import { join } from "node:path";
 
 import { MLDataStore } from "../../src/library/mldata.js";
-import { Library } from "../../src/library/index.js";
+import { Library, type RefreshEvent } from "../../src/library/index.js";
 import type { CollectionsPage, FilesPage } from "../../src/client.js";
 import type { MLData } from "../../src/mldata-fetch.js";
 import type { Collection, EnteFile } from "../../src/model/types.js";
@@ -256,12 +258,14 @@ const file = (
 
 // A mock client that serves scripted collection/file pages and per-file ML
 // payloads, recording every ML fetch request so incremental behaviour is
-// provable.
+// provable. A file in `mlErrorByFile` has ML data that did not decode, for
+// the reason given there.
 class MLMockClient {
     userID = USER_ID;
     collectionsQueue: CollectionsPage[] = [];
     filesByCollection = new Map<number, FilesPage[]>();
     mlByFile = new Map<number, MLData>();
+    mlErrorByFile = new Map<number, Error>();
     mlFetchCalls: number[][] = [];
 
     whoami(): { email: string; userID: number } {
@@ -298,14 +302,20 @@ class MLMockClient {
     async fetchMLData(args: {
         fileIDs: number[];
         fileKeys: Map<number, Uint8Array>;
-    }): Promise<Map<number, MLData>> {
+    }): Promise<{
+        payloads: Map<number, MLData>;
+        errors: Map<number, unknown>;
+    }> {
         this.mlFetchCalls.push([...args.fileIDs]);
-        const result = new Map<number, MLData>();
+        const payloads = new Map<number, MLData>();
+        const errors = new Map<number, unknown>();
         for (const id of args.fileIDs) {
             const p = this.mlByFile.get(id);
-            if (p) result.set(id, p);
+            if (p) payloads.set(id, p);
+            const error = this.mlErrorByFile.get(id);
+            if (error) errors.set(id, error);
         }
-        return result;
+        return { payloads, errors };
     }
 
     filesFor(collectionID: number, ...pages: FilesPage[]): void {
@@ -449,6 +459,137 @@ describe("Library ML-data fetch on refresh", () => {
         }
     });
 
+    it("reports a file whose ML data did not decode through status() and onProgress, and asks for it again", async () => {
+        const client = new MLMockClient();
+        client.collectionsQueue.push({
+            collections: [collection(1, 100)],
+            deleted: [],
+            cursor: 100,
+        });
+        client.filesFor(1, {
+            files: [file(1001, 1, 90), file(1002, 1, 95)],
+            deleted: [],
+            cursor: 95,
+        });
+        client.mlByFile.set(1001, payload([0.5, 0.25, 0.75]));
+        client.mlErrorByFile.set(
+            1002,
+            new Error("secretstream chunk authentication failed"),
+        );
+        const events: RefreshEvent[] = [];
+
+        const lib = await Library.open({
+            client,
+            cacheDirectory,
+            refreshIntervalSeconds: Infinity,
+            onProgress: (event) => events.push(event),
+        });
+        try {
+            await vi.waitFor(
+                () => expect(lib.status().lastMLFetchAt).toBeGreaterThan(0),
+                { timeout: 2000, interval: 5 },
+            );
+            const reasons = [
+                {
+                    fileID: 1002,
+                    error: "secretstream chunk authentication failed",
+                },
+            ];
+            expect(lib.status().mlDataErrors).toEqual(reasons);
+            expect(lib.status().mlStored).toBe(1);
+            expect(events.filter((e) => e.operation === "fetchMLData")).toEqual(
+                [
+                    { operation: "fetchMLData", status: "started" },
+                    {
+                        operation: "fetchMLData",
+                        status: "done",
+                        fetched: 1,
+                        mlDataErrors: reasons,
+                    },
+                ],
+            );
+
+            // Nothing was cached for 1002, so the pass a refresh starts asks
+            // for it again, and once its ML data decodes the reason is gone.
+            client.mlErrorByFile.clear();
+            client.mlByFile.set(1002, payload([1, -2, 0.5]));
+            await lib.fresh();
+            await vi.waitFor(
+                () => {
+                    expect(lib.status().mlStored).toBe(2);
+                    expect(lib.status().mlDataErrors).toEqual([]);
+                },
+                { timeout: 2000, interval: 5 },
+            );
+            expect(client.mlFetchCalls.at(-1)).toEqual([1002]);
+        } finally {
+            await lib.close();
+        }
+    });
+
+    it("still lists the last pass's reasons while the next pass runs", async () => {
+        const client = new MLMockClient();
+        client.collectionsQueue.push({
+            collections: [collection(1, 100)],
+            deleted: [],
+            cursor: 100,
+        });
+        client.filesFor(1, {
+            files: [file(1002, 1, 95)],
+            deleted: [],
+            cursor: 95,
+        });
+        client.mlErrorByFile.set(
+            1002,
+            new Error("secretstream chunk authentication failed"),
+        );
+        const reasons = [
+            { fileID: 1002, error: "secretstream chunk authentication failed" },
+        ];
+        let release!: () => void;
+        const held = new Promise<void>((r) => (release = r));
+
+        const lib = await Library.open({
+            client,
+            cacheDirectory,
+            refreshIntervalSeconds: Infinity,
+        });
+        try {
+            await vi.waitFor(
+                () => expect(lib.status().lastMLFetchAt).toBeGreaterThan(0),
+                { timeout: 2000, interval: 5 },
+            );
+            expect(lib.status().mlDataErrors).toEqual(reasons);
+
+            // Hold the next ML data fetch open until the test releases it.
+            let fetchStarted!: () => void;
+            const started = new Promise<void>((r) => (fetchStarted = r));
+            const realFetch = client.fetchMLData.bind(client);
+            client.fetchMLData = async (args) => {
+                fetchStarted();
+                await held;
+                return realFetch(args);
+            };
+            client.mlErrorByFile.clear();
+            client.mlByFile.set(1002, payload([1, -2, 0.5]));
+
+            // The pass a refresh starts asks for 1002 again. While it is
+            // held, the reason from the pass before is still listed; once it
+            // ends, its own empty list takes the place of that one.
+            await lib.fresh();
+            await started;
+            expect(lib.status().mlDataErrors).toEqual(reasons);
+            release();
+            await vi.waitFor(
+                () => expect(lib.status().mlDataErrors).toEqual([]),
+                { timeout: 2000, interval: 5 },
+            );
+        } finally {
+            release();
+            await lib.close();
+        }
+    });
+
     it("close() resolves only after a running ML data fetch has stored its payloads", async () => {
         const client = new MLMockClient();
         client.collectionsQueue.push({

test/mldata-fetch/mldata-fetch.test.ts

@@ -0,0 +1,54 @@
+// `fetchMLDataBatch`, against a server that sends one file's ML data.
+//
+// ML data that decrypts and gunzips but is not a JSON object is reported with
+// the reason, as ML data that does not parse is, and is never returned as a
+// payload: the library would fail to store it.
+
+import { gzipSync } from "node:zlib";
+import sodium from "libsodium-wrappers-sumo";
+import { beforeAll, describe, expect, it } from "vitest";
+
+import { ApiClient } from "../../src/api/client.js";
+import { encryptBlob, init, toBase64 } from "../../src/crypto/index.js";
+import { fetchMLDataBatch } from "../../src/mldata-fetch.js";
+
+beforeAll(async () => {
+    await init();
+    await sodium.ready;
+});
+
+// Fetch the ML data of file 1 from a server that sends `json`, gzipped and
+// encrypted with the file's key.
+const fetchServing = async (json: string) => {
+    const key = sodium.crypto_secretstream_xchacha20poly1305_keygen();
+    const { header, ciphertext } = encryptBlob(
+        new Uint8Array(gzipSync(json)),
+        key,
+    );
+    const data = [
+        {
+            fileID: 1,
+            encryptedData: toBase64(ciphertext),
+            decryptionHeader: toBase64(header),
+        },
+    ];
+    const api = new ApiClient({
+        fetch: async () =>
+            new Response(JSON.stringify({ data }), {
+                headers: { "content-type": "application/json" },
+            }),
+    });
+    return fetchMLDataBatch(api, [1], new Map([[1, key]]));
+};
+
+describe("fetchMLDataBatch", () => {
+    it.each(["null", "5", "[]"])(
+        "gives a reason for ML data that is %s",
+        async (json) => {
+            const { payloads, errors } = await fetchServing(json);
+
+            expect(payloads.size).toBe(0);
+            expect(errors.get(1)).toEqual(new Error("not a JSON object"));
+        },
+    );
+});

test/retry/retry.test.ts

@@ -77,6 +77,14 @@ const recordingSleep = (): {
 const errnoError = (code: string, message = code): Error =>
     Object.assign(new Error(message), { code });
 
+/**
+ * An error shaped like what bun's `fetch` rejects with for a failure below
+ * HTTP: a plain `Error` with bun's own message, a `code`, an `errno` of 0, and
+ * no `cause`.
+ */
+const bunError = (code: string, message: string): Error =>
+    Object.assign(new Error(message), { code, errno: 0 });
+
 // ---------------------------------------------------------------------------
 // Classification
 // ---------------------------------------------------------------------------
@@ -244,6 +252,82 @@ describe("isRetryable: transport failures", () => {
     });
 });
 
+describe("isRetryable and isSafeToReplay: bun's fetch errors", () => {
+    // The binary `make install` builds runs quak under bun, whose `fetch`
+    // does not reject as Node's does. Each shape here was found by running
+    // that binary, built with bun 1.3.13, against listeners on 127.0.0.1 and
+    // a name under `.invalid`.
+
+    it("retries a refused connection, and does not replay it", () => {
+        // Bun gives the same error when the TLS handshake fails, and when a
+        // new connection it opened to resend a request is refused. That
+        // request may already have reached the server on a connection bun
+        // kept open from an earlier request.
+        const refused = bunError(
+            "ConnectionRefused",
+            "Unable to connect. Is the computer able to access the url?",
+        );
+        expect(isRetryable(refused)).toBe(true);
+        expect(isSafeToReplay(refused)).toBe(false);
+    });
+
+    it("retries a name that does not resolve, with either code bun gives, and does not replay it", () => {
+        // For the same name bun gave `ConnectionRefused` on some requests and
+        // `FailedToOpenSocket` on others. Either can also come from a new
+        // connection bun opened to resend a request, as above.
+        for (const unresolved of [
+            bunError(
+                "ConnectionRefused",
+                "Unable to connect. Is the computer able to access the url?",
+            ),
+            bunError(
+                "FailedToOpenSocket",
+                "Was there a typo in the url or port?",
+            ),
+        ]) {
+            expect(isRetryable(unresolved)).toBe(true);
+            expect(isSafeToReplay(unresolved)).toBe(false);
+        }
+    });
+
+    it("retries a connection closed before the response ended, and does not replay it", () => {
+        // Bun gives Node's errno, `ECONNRESET`, for a reset and for a close,
+        // before the response or part-way through the body. The request may
+        // already have reached the server.
+        const reset = bunError(
+            "ECONNRESET",
+            "The socket connection was closed unexpectedly. For more information, pass `verbose: true` in the second argument to fetch()",
+        );
+        expect(isRetryable(reset)).toBe(true);
+        expect(isSafeToReplay(reset)).toBe(false);
+    });
+
+    it("retries a request that ran out of time, and does not replay it", () => {
+        // What bun's fetch rejects with when `AbortSignal.timeout()`, which
+        // bounds each JSON request, fires.
+        const timedOut = new DOMException(
+            "The operation timed out.",
+            "TimeoutError",
+        );
+        expect(isRetryable(timedOut)).toBe(true);
+        expect(isSafeToReplay(timedOut)).toBe(false);
+    });
+
+    it("does not retry a certificate bun rejects", () => {
+        // A certificate that fails verification fails the same way however
+        // often it is asked. Under Node it is retried only because every
+        // `TypeError` is.
+        expect(
+            isRetryable(
+                bunError(
+                    "DEPTH_ZERO_SELF_SIGNED_CERT",
+                    "self signed certificate",
+                ),
+            ),
+        ).toBe(false);
+    });
+});
+
 describe("isRetryable: stream truncation versus corruption", () => {
     it("retries a truncated stream", () => {
         // Truncation is a transfer that stopped early. The bytes that did
@@ -471,6 +555,36 @@ describe("withRetry", () => {
         expect(delays).toHaveLength(2);
     });
 
+    it("tells `onRetry` of each attempt it retries, before the wait", async () => {
+        // A caller that logs retries, as the CLI does with `-v`, learns why
+        // each attempt failed and how long the next one is put off. The last
+        // attempt is not retried, so it is not reported.
+        const { sleep, delays } = recordingSleep();
+        const retries: [string, number, number][] = [];
+        let calls = 0;
+        const failure = withRetry(
+            () => {
+                calls++;
+                return Promise.reject(new ApiError(`attempt ${calls}`, 503));
+            },
+            {
+                attempts: 3,
+                sleep,
+                random: () => 0.5,
+                onRetry: (err, attempt, delayMs) => {
+                    retries.push([(err as Error).message, attempt, delayMs]);
+                },
+            },
+        );
+
+        await expect(failure).rejects.toThrow("attempt 3");
+        expect(retries).toEqual([
+            ["attempt 1", 1, 250],
+            ["attempt 2", 2, 500],
+        ]);
+        expect(delays).toEqual([250, 500]);
+    });
+
     it("does not retry at all when attempts is 1", async () => {
         const { sleep, delays } = recordingSleep();
         let calls = 0;
@@ -624,6 +738,7 @@ describe("retry defaults", () => {
         expect(resolved.maxDelayMs).toBe(DEFAULT_RETRY_OPTIONS.maxDelayMs);
         expect(typeof resolved.sleep).toBe("function");
         expect(typeof resolved.random).toBe("function");
+        expect(typeof resolved.onRetry).toBe("function");
     });
 
     it("resolves to the defaults when given nothing", () => {

test/thumbnails/thumbnails.test.ts

@@ -6,10 +6,12 @@
  * working thumbnails, others return 404 or empty bodies. The tests
  * verify that the detection and repair logic handles each case correctly.
  *
- * As of issue #52 both helpers take an open `Library` for enumeration and the
+ * `listMissingThumbnails` takes an open `Library` to enumerate the files. Both
- * `Client` for the API operations that stay unchanged (the thumbnail existence
+ * helpers take the `Client` for the API operations: the thumbnail existence
- * check, and the encrypt-and-upload path). `fixMissingThumbnails` reads each
+ * check, and the encrypt-and-upload path. `fixMissingThumbnails` takes the
- * original through the library's content cache (`photo.original()`).
+ * record of each file, which these tests look up with `cachedFilesByID`. It
+ * reads each original through the library's content cache, by
+ * `lib.originalOf(file)`.
  *
  * `fixMissingThumbnails` is the most complex function in quak: it
  * downloads the original file, generates a JPEG thumbnail with jpeg-js,
@@ -41,6 +43,7 @@ import {
 import { SRP, SrpServer } from "fast-srp-hap";
 import { Client } from "../../src/client.js";
 import { Library } from "../../src/library/index.js";
+import { cachedFilesByID } from "../../src/cli-read.js";
 import {
     listMissingThumbnails,
     fixMissingThumbnails,
@@ -544,11 +547,22 @@ describe("listMissingThumbnails", () => {
         const client = await login(counted.fetch, { ...noWait });
         const lib = await openLib(client);
 
-        const missing = await listMissingThumbnails(lib, client);
+        const errors: string[] = [];
+        const missing = await listMissingThumbnails(
+            lib,
+            client,
+            (msg, level) => {
+                if (level === "error") errors.push(msg);
+            },
+        );
         lib.close();
 
-        // Only the genuinely empty thumbnail is reported.
+        // Only the genuinely empty thumbnail is reported. The file that
+        // could not be checked is reported as an error.
         expect(missing.map((m) => m.fileID)).toEqual([101]);
+        expect(errors).toEqual([
+            expect.stringMatching(/^\[.*\] Could not check file-102\.jpg: /),
+        ]);
         // And the 500 was retried rather than accepted as an answer: four
         // attempts is the library default.
         expect(counted.matched()).toBe(4);
@@ -645,7 +659,12 @@ describe("fixMissingThumbnails", () => {
         const client = await login(buildThumbFetch(fixMock));
         const lib = await openLib(client);
 
-        const results = await fixMissingThumbnails(lib, client, [101]);
+        const results = await fixMissingThumbnails(
+            lib,
+            client,
+            [101],
+            cachedFilesByID(lib, [101]),
+        );
         lib.close();
 
         expect(results.length).toBe(1);
@@ -682,7 +701,12 @@ describe("fixMissingThumbnails", () => {
         const client = await login(buildThumbFetch(fixMock));
         const lib = await openLib(client);
 
-        const results = await fixMissingThumbnails(lib, client, [999]);
+        const results = await fixMissingThumbnails(
+            lib,
+            client,
+            [999],
+            cachedFilesByID(lib, [999]),
+        );
         lib.close();
 
         expect(results.length).toBe(1);
@@ -699,7 +723,16 @@ describe("fixMissingThumbnails", () => {
         const client = await login(buildThumbFetch(fixMock));
         const lib = await openLib(client);
 
-        const results = await fixMissingThumbnails(lib, client, [101, 102]);
+        const errors: string[] = [];
+        const results = await fixMissingThumbnails(
+            lib,
+            client,
+            [101, 102],
+            cachedFilesByID(lib, [101, 102]),
+            (msg, level) => {
+                if (level === "error") errors.push(msg);
+            },
+        );
         lib.close();
 
         expect(results.length).toBe(2);
@@ -707,6 +740,10 @@ describe("fixMissingThumbnails", () => {
         const failure = results.find((r) => r.fileID === 102)!;
         expect(success.status).toBe("fixed");
         expect(failure.status).toBe("failed");
+        // The failed file, and only it, is reported as an error.
+        expect(errors).toEqual([
+            expect.stringMatching(/^\[.*\] FAILED file-102\.jpg: /),
+        ]);
     });
 
     it("skips a non-JPEG image and a video as unsupported, not failed (issue #17)", async () => {
@@ -722,6 +759,7 @@ describe("fixMissingThumbnails", () => {
             lib,
             client,
             [101, 103, 104],
+            cachedFilesByID(lib, [101, 103, 104]),
         );
         lib.close();
 
@@ -756,7 +794,12 @@ describe("fixMissingThumbnails", () => {
         const client = await login(counted.fetch);
         const lib = await openLib(client);
 
-        const results = await fixMissingThumbnails(lib, client, [101]);
+        const results = await fixMissingThumbnails(
+            lib,
+            client,
+            [101],
+            cachedFilesByID(lib, [101]),
+        );
         lib.close();
 
         expect(results[0]!.status).toBe("skipped");
@@ -777,7 +820,12 @@ describe("fixMissingThumbnails", () => {
         const client = await login(counted.fetch);
         const lib = await openLib(client);
 
-        const results = await fixMissingThumbnails(lib, client, [101]);
+        const results = await fixMissingThumbnails(
+            lib,
+            client,
+            [101],
+            cachedFilesByID(lib, [101]),
+        );
         lib.close();
 
         expect(results[0]!.status).toBe("skipped");
@@ -818,7 +866,12 @@ describe("fixMissingThumbnails", () => {
         const client = await login(buildThumbFetch(fixMock));
         const lib = await openLib(client);
 
-        const results = await fixMissingThumbnails(lib, client, [101]);
+        const results = await fixMissingThumbnails(
+            lib,
+            client,
+            [101],
+            cachedFilesByID(lib, [101]),
+        );
         lib.close();
 
         expect(results[0]!.status).toBe("fixed");