quak helper fix-missing-thumbnails --file on an empty cache stops fetching collections once it finds every file (closes #223)

`helper fix-missing-thumbnails --file` used to wait for a refresh, which
on an empty cache fetched the files of every collection. It now finds the
named files through the new `freshFilesByID` in `src/cli-read.ts`, by the
rule `freshFile` follows. On an empty cache it reads the collection list,
then one collection's files at a time, and stores none of the collections
or file records it reads. It searches the most recently updated
collection first. So a file in several albums is still named after the
first of them that `Library.albums.list()` lists. `fixMissingThumbnails`
now takes the records the command found, and fetches each original
through `lib.originalOf()`.

Model: opus-5-5

src/cli-read.ts

@@ -12,6 +12,8 @@
 // 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` with a collection ID list in the server's order.
 // `files` without one lists in the library's own enumeration order
@@ -90,3 +92,59 @@ export const freshFile = async (
     }
     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;
+};