/**
 * Tests for the in-process read surface (issue #44).
 *
 * Phase 1 (#43) projected the decrypted store into plain `AlbumRecord` /
 * `PhotoRecord` values. This phase adds the read API a CLI or in-process script
 * uses, all served from RAM with no network:
 *
 *  - `lib.albums`  — `list` / `byName` / `byID`, returning thin `Album` wrappers.
 *  - `lib.photos`  — `byID` (a `Photo` wrapper) and `records` (plain records).
 *  - `lib.timeline.groups` — photos bucketed by local day / week / month.
 *
 * Every call takes a single named-argument object; there are no positional
 * arguments. The wrapper classes are for in-process callers only (they hold
 * object identity, not JSON); the plain records remain the IPC-safe surface.
 * Content-fetch methods (`Photo.original` / `thumbnail`) are a later unit and
 * deliberately absent here — this surface is read-only.
 *
 * The detailed cases drive the API factories directly over a hand-built
 * projection (`deriveRecords`), which keeps them free of disk and timers. A
 * final section opens a real `Library` to prove the namespaces are wired to the
 * live store and that a read never touches the client.
 */

import { describe, it, expect, beforeAll, afterAll } from "vitest";
import { mkdtempSync, rmSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";

import {
    deriveRecords,
    type DerivedRecords,
} from "../../src/library/records.js";
import {
    Album,
    Photo,
    makeAlbumsAPI,
    makePhotosAPI,
    makeTimelineAPI,
    type TimelineGroup,
} from "../../src/library/read.js";
import { Library } from "../../src/library/index.js";
import { MetadataStore } from "../../src/library/store.js";
import type { CollectionsPage, FilesPage } from "../../src/client.js";
import type { Collection, EnteFile } from "../../src/model/types.js";

const OWNER = 42;

// Ente stores times in microseconds; records expose milliseconds. These
// helpers keep the fixtures readable: `ms(...)` picks an epoch-millisecond
// instant, `micros(...)` is what the fixture stores so the derived record's
// `takenAt` comes back as the same millisecond value.
const ms = (epochMillis: number): number => epochMillis;
const micros = (epochMillis: number): number => epochMillis * 1000;

const collection = (
    id: number,
    opts: Partial<Collection> = {},
): Collection => ({
    id,
    ownerID: OWNER,
    key: new Uint8Array([id & 0xff, 1, 2, 3]),
    name: `album-${id}`,
    type: "album",
    updationTime: micros(1_700_000_000_000),
    isShared: false,
    ...opts,
});

const file = (
    id: number,
    collectionID: number,
    opts: Partial<EnteFile> & {
        creationTime?: number;
        title?: string;
        fileType?: EnteFile["metadata"]["fileType"];
        latitude?: number;
        longitude?: number;
    } = {},
): EnteFile => {
    const { creationTime, title, fileType, latitude, longitude, ...rest } =
        opts;
    const metadata: EnteFile["metadata"] = {
        title: title ?? `file-${id}.jpg`,
        fileType: fileType ?? "image",
        creationTime: creationTime ?? micros(1_700_000_000_000),
        modificationTime: micros(1_700_000_000_000),
    };
    if (latitude !== undefined) metadata.latitude = latitude;
    if (longitude !== undefined) metadata.longitude = longitude;
    return {
        id,
        collectionID,
        ownerID: OWNER,
        key: new Uint8Array([id & 0xff, 9, 8, 7]),
        metadata,
        file: { decryptionHeader: "aGVhZGVy" },
        thumbnail: { decryptionHeader: "dGh1bWI=" },
        updationTime: micros(1_700_000_000_000),
        ...rest,
    };
};

// Build the three API objects over one fixed projection, the way `Library`
// wires them over its live store.
const apis = (records: DerivedRecords) => {
    const derive = () => records;
    return {
        albums: makeAlbumsAPI(derive),
        photos: makePhotosAPI(derive),
        timeline: makeTimelineAPI(derive),
    };
};

// Every file id present across all timeline groups, in group-then-member order.
const allFileIDs = (groups: TimelineGroup[]): number[] =>
    groups.flatMap((g) => g.fileIDs);

describe("lib.albums", () => {
    it("lists albums as Album wrappers, newest updated first", () => {
        const records = deriveRecords(
            [
                collection(1, { updationTime: micros(1_700_000_000_000) }),
                collection(2, { updationTime: micros(1_705_000_000_000) }),
            ],
            [file(10, 1), file(20, 2)],
        );
        const albums = apis(records).albums.list();
        expect(albums.every((a) => a instanceof Album)).toBe(true);
        // Collection 2 updated later, so it sorts ahead of collection 1.
        expect(albums.map((a) => a.collectionID)).toEqual([2, 1]);
    });

    it("exposes album fields and its photos newest first", () => {
        const records = deriveRecords(
            [
                collection(7, {
                    name: "Trip",
                    type: "favorites",
                    isShared: true,
                }),
            ],
            [
                file(1, 7, { creationTime: micros(1_600_000_000_000) }),
                file(2, 7, { creationTime: micros(1_800_000_000_000) }),
                file(3, 7, { creationTime: micros(1_700_000_000_000) }),
            ],
        );
        const album = apis(records).albums.byID({ collectionID: 7 })!;
        expect(album.name).toBe("Trip");
        expect(album.type).toBe("favorites");
        expect(album.isShared).toBe(true);
        expect(album.fileIDs).toEqual([2, 3, 1]);

        const photos = album.photos.list();
        expect(photos.every((p) => p instanceof Photo)).toBe(true);
        expect(photos.map((p) => p.fileID)).toEqual([2, 3, 1]);

        // record() hands back the plain, JSON-safe projection.
        expect("key" in album.record()).toBe(false);
    });

    it("finds an album by exact name and returns undefined when absent", () => {
        const records = deriveRecords(
            [
                collection(1, { name: "Berlin" }),
                collection(2, { name: "Paris" }),
            ],
            [file(10, 1), file(20, 2)],
        );
        const { albums } = apis(records);
        expect(albums.byName({ albumName: "Paris" })?.collectionID).toBe(2);
        expect(albums.byName({ albumName: "paris" })).toBeUndefined();
        expect(albums.byName({ albumName: "Nowhere" })).toBeUndefined();
    });

    it("returns undefined for an unknown collection id", () => {
        const records = deriveRecords([collection(1)], [file(10, 1)]);
        expect(
            apis(records).albums.byID({ collectionID: 999 }),
        ).toBeUndefined();
    });
});

describe("lib.photos", () => {
    it("byID returns a Photo wrapper carrying the mapped fields", () => {
        const records = deriveRecords(
            [collection(1)],
            [
                file(1001, 1, {
                    title: "IMG.jpg",
                    fileType: "video",
                    creationTime: micros(1_699_000_000_000),
                    latitude: 52.52,
                    longitude: 13.405,
                    pubMagicMetadata: { caption: "at the lake" },
                }),
            ],
        );
        const photo = apis(records).photos.byID({ fileID: 1001 })!;
        expect(photo).toBeInstanceOf(Photo);
        expect(photo.title).toBe("IMG.jpg");
        expect(photo.fileType).toBe("video");
        expect(photo.takenAt).toBe(ms(1_699_000_000_000));
        expect(photo.caption).toBe("at the lake");
        expect(photo.latitude).toBeCloseTo(52.52);
        expect(photo.isArchived).toBe(false);
        expect(photo.isHidden).toBe(false);
        // The wrapper hands back the plain record, IPC-safe.
        expect("key" in photo.record()).toBe(false);
    });

    it("byID returns undefined for an unknown file id", () => {
        const records = deriveRecords([collection(1)], [file(1, 1)]);
        expect(apis(records).photos.byID({ fileID: 999 })).toBeUndefined();
    });

    it("records() returns plain records in requested order, deduped, skipping unknowns", () => {
        const records = deriveRecords(
            [collection(1)],
            [file(1, 1), file(2, 1), file(3, 1)],
        );
        const out = apis(records).photos.records({
            fileIDs: [3, 1, 3, 999, 2],
        });
        // Requested order preserved; the repeated 3 appears once; 999 is dropped.
        expect(out.map((r) => r.fileID)).toEqual([3, 1, 2]);
        // Plain records, not wrappers, and JSON round-trips whole.
        expect(out[0]).not.toBeInstanceOf(Photo);
        expect(JSON.parse(JSON.stringify(out[0]))).toEqual(out[0]);
    });

    it("emits one record for a file even when it belongs to several albums", () => {
        // File 1001 is a member of collections 1 and 2.
        const records = deriveRecords(
            [collection(1), collection(2)],
            [file(1001, 1), file(1001, 2)],
        );
        const out = apis(records).photos.records({ fileIDs: [1001, 1001] });
        expect(out).toHaveLength(1);
        expect(out[0]!.albumIDs).toEqual([1, 2]);
    });
});

describe("lib.timeline grouping", () => {
    // Group keys and `startsAt` are computed in local time. Pinning the zone to
    // UTC makes the expected values exact and lets the fixtures use `Date.UTC`.
    const savedTZ = process.env.TZ;
    beforeAll(() => {
        process.env.TZ = "UTC";
    });
    afterAll(() => {
        if (savedTZ === undefined) delete process.env.TZ;
        else process.env.TZ = savedTZ;
    });

    it("buckets by local day, newest group and newest member first", () => {
        const records = deriveRecords(
            [collection(1)],
            [
                file(1, 1, { creationTime: micros(Date.UTC(2024, 0, 15, 9)) }),
                file(2, 1, { creationTime: micros(Date.UTC(2024, 0, 15, 18)) }),
                file(3, 1, { creationTime: micros(Date.UTC(2024, 0, 16, 12)) }),
                file(4, 1, { creationTime: micros(Date.UTC(2024, 1, 1, 12)) }),
            ],
        );
        const groups = apis(records).timeline.groups({ groupBy: "day" });
        expect(groups.map((g) => g.key)).toEqual([
            "2024-02-01",
            "2024-01-16",
            "2024-01-15",
        ]);
        // Group start is local midnight of the day.
        expect(groups[2]!.startsAt).toBe(Date.UTC(2024, 0, 15));
        // Within the 2024-01-15 group, the later photo (id 2) is first.
        expect(groups[2]!.fileIDs).toEqual([2, 1]);
    });

    it("buckets by week with weeks starting on Monday", () => {
        // 2024-01-15 is a Monday; the week runs through Sunday 2024-01-21.
        const records = deriveRecords(
            [collection(1)],
            [
                file(1, 1, { creationTime: micros(Date.UTC(2024, 0, 15, 12)) }), // Mon
                file(2, 1, { creationTime: micros(Date.UTC(2024, 0, 17, 12)) }), // Wed
                file(3, 1, { creationTime: micros(Date.UTC(2024, 0, 21, 12)) }), // Sun
                file(4, 1, { creationTime: micros(Date.UTC(2024, 0, 22, 12)) }), // next Mon
            ],
        );
        const groups = apis(records).timeline.groups({ groupBy: "week" });
        // ISO week keys: 2024-01-15 is in 2024-W03, the next Monday in 2024-W04.
        expect(groups.map((g) => g.key)).toEqual(["2024-W04", "2024-W03"]);
        const first = groups.find((g) => g.key === "2024-W03")!;
        expect(first.startsAt).toBe(Date.UTC(2024, 0, 15));
        // The Sunday belongs to the Monday-started week, not the next one.
        expect(first.fileIDs.sort((a, b) => a - b)).toEqual([1, 2, 3]);
    });

    it("assigns a Sunday to the preceding Monday's week across a month boundary", () => {
        // 2024-01-14 is a Sunday; its week started Monday 2024-01-08.
        const records = deriveRecords(
            [collection(1)],
            [file(1, 1, { creationTime: micros(Date.UTC(2024, 0, 14, 12)) })],
        );
        const groups = apis(records).timeline.groups({ groupBy: "week" });
        expect(groups.map((g) => g.key)).toEqual(["2024-W02"]);
        expect(groups[0]!.startsAt).toBe(Date.UTC(2024, 0, 8));
    });

    it("buckets by month", () => {
        const records = deriveRecords(
            [collection(1)],
            [
                file(1, 1, { creationTime: micros(Date.UTC(2024, 0, 3, 12)) }),
                file(2, 1, { creationTime: micros(Date.UTC(2024, 0, 28, 12)) }),
                file(3, 1, { creationTime: micros(Date.UTC(2024, 1, 9, 12)) }),
            ],
        );
        const groups = apis(records).timeline.groups({ groupBy: "month" });
        expect(groups.map((g) => g.key)).toEqual(["2024-02", "2024-01"]);
        expect(groups[1]!.startsAt).toBe(Date.UTC(2024, 0, 1));
        expect(groups[1]!.fileIDs).toEqual([2, 1]);
    });

    it("lists each file once even when it belongs to several albums", () => {
        // File 1001 is in collections 1 and 2 but must appear once in a group.
        const records = deriveRecords(
            [collection(1), collection(2)],
            [
                file(1001, 1, {
                    creationTime: micros(Date.UTC(2024, 0, 15, 12)),
                }),
                file(1001, 2, {
                    creationTime: micros(Date.UTC(2024, 0, 15, 12)),
                }),
            ],
        );
        const groups = apis(records).timeline.groups({ groupBy: "day" });
        expect(allFileIDs(groups)).toEqual([1001]);
    });
});

describe("lib.timeline uses local time, not UTC", () => {
    const savedTZ = process.env.TZ;
    afterAll(() => {
        if (savedTZ === undefined) delete process.env.TZ;
        else process.env.TZ = savedTZ;
    });

    it("buckets by the viewer's local day", () => {
        // Kolkata is UTC+5:30 with no DST. An instant at 2024-01-14T20:00Z is
        // 2024-01-15 01:30 local, so it belongs to the local day 2024-01-15.
        process.env.TZ = "Asia/Kolkata";
        const records = deriveRecords(
            [collection(1)],
            [file(1, 1, { creationTime: micros(Date.UTC(2024, 0, 14, 20)) })],
        );
        const groups = apis(records).timeline.groups({ groupBy: "day" });
        expect(groups[0]!.key).toBe("2024-01-15");
        // Local midnight of 2024-01-15, which is 2024-01-14T18:30Z.
        expect(groups[0]!.startsAt).toBe(new Date(2024, 0, 15).getTime());
        expect(groups[0]!.startsAt).toBe(Date.UTC(2024, 0, 14, 18, 30));
    });
});

describe("PhotoFilter", () => {
    // A fixture spanning albums, file types, geotags, captions, and the two
    // visibility states, all on the same local day so grouping is incidental.
    const day = (h: number): number => micros(Date.UTC(2024, 2, 4, h));
    const records = (): DerivedRecords =>
        deriveRecords(
            [
                collection(1, { name: "Holidays" }),
                collection(2, { name: "Work" }),
            ],
            [
                file(1, 1, {
                    title: "Beach sunset",
                    creationTime: day(1),
                    latitude: 1,
                    longitude: 2,
                }),
                file(2, 1, {
                    title: "clip.mov",
                    fileType: "video",
                    creationTime: day(2),
                }),
                file(3, 2, {
                    title: "invoice scan",
                    creationTime: day(3),
                    pubMagicMetadata: { caption: "SUNSET colours" },
                }),
                file(4, 2, {
                    title: "archived note",
                    creationTime: day(4),
                    magicMetadata: { visibility: 1 },
                }),
                file(5, 2, {
                    title: "secret",
                    creationTime: day(5),
                    magicMetadata: { visibility: 2 },
                }),
            ],
        );

    const idsWith = (
        filter: Parameters<
            ReturnType<typeof apis>["timeline"]["groups"]
        >[0]["filter"],
    ): number[] =>
        allFileIDs(
            apis(records()).timeline.groups({ groupBy: "day", filter }),
        ).sort((a, b) => a - b);

    it("never includes hidden photos and excludes archived by default", () => {
        // No filter: hidden (5) always gone, archived (4) gone unless asked for.
        expect(idsWith(undefined)).toEqual([1, 2, 3]);
    });

    it("includes archived photos when includeArchived is set, hidden still never", () => {
        expect(idsWith({ includeArchived: true })).toEqual([1, 2, 3, 4]);
    });

    it("filters by album membership", () => {
        expect(idsWith({ albumID: 1 })).toEqual([1, 2]);
        expect(idsWith({ albumID: 2 })).toEqual([3]);
    });

    it("filters by file type", () => {
        expect(idsWith({ fileTypes: ["video"] })).toEqual([2]);
        expect(idsWith({ fileTypes: ["image", "video"] })).toEqual([1, 2, 3]);
    });

    it("filters by presence or absence of location", () => {
        expect(idsWith({ hasLocation: true })).toEqual([1]);
        expect(idsWith({ hasLocation: false })).toEqual([2, 3]);
    });

    it("matches text case-insensitively against title, caption, and album name", () => {
        // Title match (case-insensitive): "Beach sunset".
        expect(idsWith({ text: "SUNSET" })).toEqual([1, 3]);
        // Caption-only match: file 3's caption is "SUNSET colours".
        expect(idsWith({ text: "colours" })).toEqual([3]);
        // Album-name match: everything in "Holidays".
        expect(idsWith({ text: "holiday" })).toEqual([1, 2]);
    });

    it("combines filters", () => {
        // Images in album 1 with a location: only file 1.
        expect(
            idsWith({ albumID: 1, fileTypes: ["image"], hasLocation: true }),
        ).toEqual([1]);
    });
});

/**
 * A minimal mock `Client`, enough for `Library.open` to run its refresh loop.
 * The queues are empty, so the background refresh over a seeded cache changes
 * nothing; the counters prove that a read never calls the client.
 */
class MockClient {
    userID = OWNER;
    collectionsCalls = 0;
    filesCalls = 0;

    whoami(): { email: string; userID: number } {
        return { email: "user@example.com", userID: this.userID };
    }
    async collectionsSince(args: {
        sinceTime: number;
    }): Promise<CollectionsPage> {
        this.collectionsCalls++;
        return { collections: [], deleted: [], cursor: args.sinceTime };
    }
    async filesSince(args: {
        collectionID: number;
        collectionKey: Uint8Array;
        sinceTime: number;
    }): Promise<FilesPage> {
        this.filesCalls++;
        return { files: [], deleted: [], cursor: args.sinceTime };
    }
}

describe("Library exposes the read surface over its live store", () => {
    let dir: string;

    beforeAll(() => {
        dir = mkdtempSync(join(tmpdir(), "quak-read-"));
    });
    afterAll(() => {
        rmSync(dir, { recursive: true, force: true });
    });

    it("serves albums, photos, and timeline from RAM without calling the client", async () => {
        const cacheDirectory = join(dir, "cache");
        const path = join(cacheDirectory, "metadata.json");

        // Seed a cache as a prior run left it, so open() serves it at once.
        const seed = await MetadataStore.load(path);
        seed.userID = OWNER;
        seed.collectionsSinceTime = 100;
        seed.putCollection(collection(1, { name: "Seeded" }));
        seed.putFile(
            file(1001, 1, { creationTime: micros(Date.UTC(2024, 5, 1, 12)) }),
        );
        await seed.save();

        const client = new MockClient();
        // A long interval keeps the background timer from firing during the test.
        const lib = await Library.open({
            client,
            cacheDirectory,
            refreshIntervalSeconds: 3600,
        });
        try {
            const collectionsBefore = client.collectionsCalls;
            const filesBefore = client.filesCalls;

            expect(lib.albums.list().map((a) => a.name)).toEqual(["Seeded"]);
            expect(
                lib.albums.byName({ albumName: "Seeded" })?.collectionID,
            ).toBe(1);
            expect(lib.photos.byID({ fileID: 1001 })?.fileID).toBe(1001);
            expect(
                lib.photos.records({ fileIDs: [1001] }).map((r) => r.fileID),
            ).toEqual([1001]);
            const groups = lib.timeline.groups({ groupBy: "month" });
            expect(allFileIDs(groups)).toEqual([1001]);

            // Reads are answered from RAM: no read called the client.
            expect(client.collectionsCalls).toBe(collectionsBefore);
            expect(client.filesCalls).toBe(filesBefore);
        } finally {
            await lib.close();
        }
    });
});