/**
 * Integration between `Library` and the content cache (issue #46).
 *
 * The cache itself is covered in `content.test.ts`; this file locks the wiring:
 * `Library.open` builds the cache from a content source, `lib.photos` hands out
 * `Photo` objects that fetch through it, `lib.thumbnails.ensure` drives it, and
 * a cached path shows up on the projected record. A library opened without a
 * content source leaves those methods throwing rather than silently doing
 * nothing.
 */

import { describe, it, expect, beforeEach, afterEach } from "vitest";
import {
    mkdtempSync,
    readdirSync,
    rmSync,
    existsSync,
    writeFileSync,
} from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";

import { Library, type LibraryOptions } from "../../src/library/index.js";
import type { ContentSource } from "../../src/library/content.js";
import type { CollectionsPage, FilesPage } from "../../src/client.js";
import type { Collection, EnteFile } from "../../src/model/types.js";
import { asLivePhoto, cdnSource, livePhotoZip } from "../live-photo.js";

const USER_ID = 7;

const collection = (id: number): Collection => ({
    id,
    ownerID: USER_ID,
    key: new Uint8Array([id & 0xff]),
    name: `album-${id}`,
    type: "album",
    updationTime: 1,
    isShared: false,
});

const file = (id: number, collectionID: number): EnteFile => ({
    id,
    collectionID,
    ownerID: USER_ID,
    key: new Uint8Array([id & 0xff]),
    metadata: {
        title: `file-${id}.jpg`,
        fileType: "image",
        creationTime: 1,
        modificationTime: 1,
    },
    file: { decryptionHeader: "aGVhZGVy" },
    thumbnail: { decryptionHeader: "dGh1bWI=" },
    updationTime: 1,
});

// A metadata-only client serving one album with one file, once.
class MockClient {
    served = false;
    whoami(): { email: string; userID: number } {
        return { email: "u@example.com", userID: USER_ID };
    }
    async collectionsSince(): Promise<CollectionsPage> {
        if (this.served) return { collections: [], deleted: [], cursor: 1 };
        this.served = true;
        return { collections: [collection(1)], deleted: [], cursor: 1 };
    }
    async filesSince(): Promise<FilesPage> {
        return { files: [file(1, 1)], deleted: [], cursor: 1 };
    }
}

// A content source that writes a marker file and counts thumbnail fetches.
const stubSource = (): ContentSource & { thumbCalls: () => number } => {
    let thumbCalls = 0;
    return {
        thumbCalls: () => thumbCalls,
        original: async ({ destination }) => {
            writeFileSync(destination, "orig-bytes");
            return { bytesWritten: 10 };
        },
        thumbnail: async ({ destination }) => {
            thumbCalls++;
            writeFileSync(destination, "thumb");
            return { bytesWritten: 5 };
        },
    };
};

let root: string;

beforeEach(() => {
    root = mkdtempSync(join(tmpdir(), "quak-content-lib-"));
});

afterEach(() => {
    if (root && existsSync(root))
        rmSync(root, { recursive: true, force: true });
});

describe("Library content wiring", () => {
    it("fetches a thumbnail through a Photo and records its cache path", async () => {
        const source = stubSource();
        const lib = await Library.open({
            client: new MockClient(),
            cacheDirectory: join(root, "cache"),
            contentSource: source,
            refreshIntervalSeconds: 3600,
            // On-demand wiring only; the background precache (#48) is covered
            // in precache.test.ts and would race the exact-count assertions.
            precacheThumbnails: false,
            precacheOriginals: false,
        });

        const photo = lib.photos.byID({ fileID: 1 });
        expect(photo).toBeDefined();
        const result = await photo!.thumbnail();
        expect(source.thumbCalls()).toBe(1);
        expect(result.path).toBe(join(root, "cache", "thumbnails", "1.jpg"));
        expect(existsSync(result.path)).toBe(true);

        // The cached path is now on the projected record.
        expect(lib.photos.byID({ fileID: 1 })!.record().thumbnailPath).toBe(
            result.path,
        );
        await lib.close();
    });

    it("drives thumbnails.ensure through the cache", async () => {
        const source = stubSource();
        const lib = await Library.open({
            client: new MockClient(),
            cacheDirectory: join(root, "cache"),
            contentSource: source,
            refreshIntervalSeconds: 3600,
            // On-demand wiring only; the background precache (#48) is covered
            // in precache.test.ts and would race the exact-count assertions.
            precacheThumbnails: false,
            precacheOriginals: false,
        });

        const results = await lib.thumbnails.ensure({
            fileIDs: [1],
            priority: "visible",
        });
        expect(results).toEqual([
            { fileID: 1, path: join(root, "cache", "thumbnails", "1.jpg") },
        ]);
        await lib.close();
    });

    it("removes a live photo's ZIP an earlier version cached when it opens, and precaches its image and video", async () => {
        const { file: live, body } = await asLivePhoto(file(1, 1));
        class LiveClient extends MockClient {
            override async filesSince(): Promise<FilesPage> {
                return { files: [live], deleted: [], cursor: 1 };
            }
        }
        const originals = join(root, "cache", "originals");
        const open = (opts: Partial<LibraryOptions>): Promise<Library> =>
            Library.open({
                client: new LiveClient(),
                cacheDirectory: join(root, "cache"),
                contentSource: cdnSource(new Map([[1, body]])),
                refreshIntervalSeconds: 3600,
                precacheThumbnails: false,
                precacheOriginals: false,
                ...opts,
            });
        // A first run records the library, so the next one knows that file 1
        // is a live photo when it opens the cache.
        await (await open({})).close();
        writeFileSync(join(originals, "1.jpg"), livePhotoZip());

        let precached!: () => void;
        const done = new Promise<void>((r) => (precached = r));
        const lib = await open({
            precacheOriginals: true,
            onProgress: (e) => {
                if (e.operation === "precacheOriginals" && e.status === "done")
                    precached();
            },
        });
        expect(existsSync(join(originals, "1.jpg"))).toBe(false);
        await done;

        expect(readdirSync(originals).sort()).toEqual([
            "1.heic",
            "1.livephoto.json",
            "1.mov",
        ]);
        expect(lib.photos.byID({ fileID: 1 })!.record().originalPath).toBe(
            join(originals, "1.heic"),
        );
        await lib.close();
    });

    it("throws from content methods when opened without a content source", async () => {
        const lib = await Library.open({
            client: new MockClient(),
            cacheDirectory: join(root, "cache"),
            refreshIntervalSeconds: 3600,
        });

        await expect(
            lib.photos.byID({ fileID: 1 })!.thumbnail(),
        ).rejects.toThrow(/content cache/i);
        await expect(
            lib.thumbnails.ensure({ fileIDs: [1], priority: "visible" }),
        ).rejects.toThrow(/content cache/i);
        await lib.close();
    });
});