import { createHash } from "node:crypto";
import { mkdtemp, readdir, readFile, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";
import type { ClientMediaItem, MediaAsset, MediaUpload } from "@rakazo/contracts";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import type { PhotosHelper } from "./media-photos-helper.js";
import type { MediaSyncApi, PhotosSyncState, PhotosSyncStore } from "./media-photos-sync.js";
import {
  createChunkUploader,
  createPhotosSyncFileStore,
  parsePhotosSyncState,
  runPool,
  syncApplePhotos,
} from "./media-photos-sync.js";

const sha = (bytes: string | Buffer) => createHash("sha256").update(bytes).digest("hex");

function libraryItem(index: number): ClientMediaItem {
  return {
    externalId: `ASSET-${String(index).padStart(5, "0")}/L0/001`,
    kind: index % 3 === 0 ? "video" : "photo",
    capturedAt: new Date(Date.UTC(2024, 0, 1) + index * 60_000).toISOString(),
    durationMs: index % 3 === 0 ? 5000 : null,
    width: 1920,
    height: 1080,
    fps: null,
    gpsLat: null,
    gpsLon: null,
    deviceModel: null,
    albumNames: [],
    isFavorite: false,
    fileName: `IMG_${index}.JPG`,
  };
}

/** Pages a synthetic library the way the Swift helper does: opaque cursor = next index. */
function fakeHelper(options: { size: number; contents?: (id: string) => string }) {
  const library = Array.from({ length: options.size }, (_, index) => libraryItem(index));
  const exports: string[] = [];
  let active = 0;
  const stats = { maxActiveExports: 0 };
  const helper: PhotosHelper & { library: ClientMediaItem[] } = {
    library,
    authorize: vi.fn(async () => "authorized" as const),
    list: vi.fn(async ({ cursor, limit }) => {
      const start = cursor === null ? 0 : Number(cursor);
      const items = library.slice(start, start + limit);
      const next = start + limit < library.length ? String(start + limit) : null;
      return { items, nextCursor: next, changeToken: `token-${library.length}` };
    }),
    asset: vi.fn(),
    changes: vi.fn(),
    exportOriginal: vi.fn(async (id: string, destination: string, opts) => {
      active += 1;
      stats.maxActiveExports = Math.max(stats.maxActiveExports, active);
      try {
        await new Promise((resolve) => setTimeout(resolve, 5));
        opts?.signal?.throwIfAborted();
        const contents = options.contents?.(id) ?? `original bytes of ${id}`;
        const file = path.join(destination, "IMG.MOV");
        await writeFile(file, contents);
        exports.push(destination);
        return {
          path: file,
          fileName: "IMG.MOV",
          sizeBytes: Buffer.byteLength(contents),
          sha256: sha(contents),
        };
      } finally {
        active -= 1;
      }
    }),
  };
  return { helper, exports, stats };
}

function memoryStore(initial?: PhotosSyncState) {
  let state: PhotosSyncState = initial ?? { version: 1, deviceId: "device-1", targets: {} };
  const writes: PhotosSyncState[] = [];
  const store: PhotosSyncStore = {
    read: async () => JSON.parse(JSON.stringify(state)) as PhotosSyncState,
    write: async (next) => {
      state = JSON.parse(JSON.stringify(next)) as PhotosSyncState;
      writes.push(state);
    },
  };
  return { store, writes, current: () => state };
}

function asset(id: string, externalId: string | undefined, ingestState: MediaAsset["ingestState"]) {
  return {
    id,
    sourceId: "source-1",
    kind: "video",
    storage: "remote",
    capturedAt: null,
    durationMs: null,
    width: null,
    height: null,
    fps: null,
    gpsLat: null,
    gpsLon: null,
    deviceModel: null,
    albumNames: [],
    isFavorite: false,
    ingestState,
    hasProxy: false,
    hasThumbnail: false,
    qualityScore: null,
    createdAt: "2024-01-01T00:00:00.000Z",
    ...(externalId === undefined ? {} : { externalId }),
  } as MediaAsset;
}

function fakeApi(
  options: {
    assets?: MediaAsset[];
    chunkBytes?: number;
    uploads?: Record<string, MediaUpload>;
  } = {},
) {
  const uploads = new Map(Object.entries(options.uploads ?? {}));
  const pushes: { items: number; syncToken: string | null; complete: boolean }[] = [];
  const chunkBytes = options.chunkBytes ?? 4;
  const api = {
    media: {
      sources: {
        registerClient: vi.fn(async (input: { deviceId: string }) => ({
          id: "source-1",
          kind: "apple_photos" as const,
          label: "Apple Photos",
          status: "idle" as const,
          assetCount: 0,
          lastSyncedAt: null,
          error: null,
          createdAt: "2024-01-01T00:00:00.000Z",
          deviceId: input.deviceId,
        })),
        pushItems: vi.fn(
          async (input: { items: unknown[]; syncToken: string | null; complete: boolean }) => {
            expect(input.items.length).toBeGreaterThan(0);
            expect(input.items.length).toBeLessThanOrEqual(500);
            pushes.push({
              items: input.items.length,
              syncToken: input.syncToken,
              complete: input.complete,
            });
            return { created: input.items.length, updated: 0, unchanged: 0 };
          },
        ),
      },
      assets: {
        search: vi.fn(async (input: { cursor?: string | null }) => {
          const all = options.assets ?? [];
          // Two pages to exercise pagination.
          const half = Math.ceil(all.length / 2);
          return input.cursor === "p2"
            ? { items: all.slice(half), nextCursor: null }
            : { items: all.slice(0, half), nextCursor: all.length > 1 ? "p2" : null };
        }),
      },
      uploads: {
        begin: vi.fn(async (input: { assetId: string; sizeBytes: number }) => {
          const upload: MediaUpload = {
            id: `upload-${input.assetId}`,
            assetId: input.assetId,
            sizeBytes: input.sizeBytes,
            chunkBytes,
            receivedChunks: [],
            status: "open",
          };
          uploads.set(upload.id, upload);
          return upload;
        }),
        status: vi.fn(async (input: { uploadId: string }) => {
          const upload = uploads.get(input.uploadId);
          if (!upload) throw Object.assign(new Error("Not found"), { code: "NOT_FOUND" });
          return upload;
        }),
        complete: vi.fn(async (input: { uploadId: string }) => {
          const upload = uploads.get(input.uploadId)!;
          return { ...upload, status: "complete" as const };
        }),
      },
    },
  };
  return { api: api as unknown as MediaSyncApi & typeof api, pushes };
}

let tempRoot: string;

beforeEach(async () => {
  tempRoot = await mkdtemp(path.join(tmpdir(), "rakazo-photos-sync-"));
});

afterEach(async () => {
  await rm(tempRoot, { recursive: true, force: true });
});

const baseOptions = () => ({
  target: "https://rakazo.example.com#space_1",
  label: "Apple Photos",
  tempRoot,
  signal: new AbortController().signal,
});

describe("Apple Photos metadata sync", () => {
  it("registers once, pushes batches of at most 500 and completes the listing", async () => {
    const { helper } = fakeHelper({ size: 1203 });
    const { api, pushes } = fakeApi();
    const { store, current } = memoryStore();
    const chunks = vi.fn();

    const result = await syncApplePhotos({
      ...baseOptions(),
      helper,
      api,
      store,
      uploadChunk: chunks,
    });

    expect(api.media.sources.registerClient).toHaveBeenCalledWith(
      { kind: "apple_photos", label: "Apple Photos", deviceId: "device-1" },
      expect.anything(),
    );
    expect(pushes).toEqual([
      { items: 500, syncToken: null, complete: false },
      { items: 500, syncToken: null, complete: false },
      { items: 203, syncToken: "token-1203", complete: true },
    ]);
    expect(result).toMatchObject({ indexed: 1203, created: 1203, uploaded: 0, fullListing: true });
    expect(current().targets["https://rakazo.example.com#space_1"]).toEqual({
      sourceId: "source-1",
      listing: null,
      changeToken: "token-1203",
      uploads: {},
    });

    // The next run reads changes only and does not register again.
    vi.mocked(helper.changes).mockResolvedValueOnce({
      token: "token-next",
      changed: [libraryItem(1), libraryItem(2)],
      deleted: [],
      fullResyncRequired: false,
    });
    const second = await syncApplePhotos({
      ...baseOptions(),
      helper,
      api,
      store,
      uploadChunk: chunks,
    });
    expect(api.media.sources.registerClient).toHaveBeenCalledTimes(1);
    expect(helper.changes).toHaveBeenCalledWith("token-1203", expect.anything());
    expect(pushes.at(-1)).toEqual({ items: 2, syncToken: "token-next", complete: false });
    expect(second.fullListing).toBe(false);
    expect(current().targets["https://rakazo.example.com#space_1"]?.changeToken).toBe("token-next");
  });

  it("persists the cursor after every batch and resumes an interrupted listing", async () => {
    const { helper } = fakeHelper({ size: 1100 });
    const { api, pushes } = fakeApi();
    const { store, writes, current } = memoryStore();
    vi.mocked(api.media.sources.pushItems).mockImplementationOnce(async (input) => {
      pushes.push({
        items: input.items.length,
        syncToken: input.syncToken,
        complete: input.complete,
      });
      return { created: input.items.length, updated: 0, unchanged: 0 };
    });
    vi.mocked(api.media.sources.pushItems).mockRejectedValueOnce(new Error("network down"));

    await expect(
      syncApplePhotos({ ...baseOptions(), helper, api, store, uploadChunk: vi.fn() }),
    ).rejects.toThrow("network down");
    const interrupted = current().targets["https://rakazo.example.com#space_1"]!;
    expect(interrupted.listing).toMatchObject({ cursor: "500", token: "token-1100" });
    expect(interrupted.listing?.lastItem?.externalId).toBe(libraryItem(499).externalId);
    expect(writes.length).toBeGreaterThan(1);

    await syncApplePhotos({ ...baseOptions(), helper, api, store, uploadChunk: vi.fn() });
    expect(vi.mocked(helper.list).mock.calls.at(-2)?.[0]).toMatchObject({ cursor: "500" });
    expect(pushes.slice(1)).toEqual([
      { items: 500, syncToken: null, complete: false },
      { items: 100, syncToken: "token-1100", complete: true },
    ]);
    expect(current().targets["https://rakazo.example.com#space_1"]).toMatchObject({
      listing: null,
      changeToken: "token-1100",
    });
  });

  it("closes a resumed listing whose last page came back empty", async () => {
    const { helper } = fakeHelper({ size: 0 });
    const { api, pushes } = fakeApi();
    const last = libraryItem(7);
    const { store } = memoryStore({
      version: 1,
      deviceId: "device-1",
      targets: {
        "https://rakazo.example.com#space_1": {
          sourceId: "source-1",
          listing: { cursor: "500", token: "token-a", lastItem: last },
          changeToken: null,
          uploads: {},
        },
      },
    });
    await syncApplePhotos({ ...baseOptions(), helper, api, store, uploadChunk: vi.fn() });
    expect(pushes).toEqual([{ items: 1, syncToken: "token-a", complete: true }]);
  });

  it("relists everything when items were deleted or the token expired", async () => {
    const { helper } = fakeHelper({ size: 3 });
    const { api, pushes } = fakeApi();
    const { store } = memoryStore({
      version: 1,
      deviceId: "device-1",
      targets: {
        "https://rakazo.example.com#space_1": {
          sourceId: "source-1",
          listing: null,
          changeToken: "old",
          uploads: {},
        },
      },
    });
    vi.mocked(helper.changes).mockResolvedValueOnce({
      token: "new",
      changed: [],
      deleted: ["gone/L0/001"],
      fullResyncRequired: false,
    });
    const result = await syncApplePhotos({
      ...baseOptions(),
      helper,
      api,
      store,
      uploadChunk: vi.fn(),
    });
    expect(result.fullListing).toBe(true);
    expect(pushes).toEqual([{ items: 3, syncToken: "token-3", complete: true }]);
  });

  it("registers again when the server no longer knows the source", async () => {
    const { helper } = fakeHelper({ size: 2 });
    const { api } = fakeApi();
    const { store } = memoryStore({
      version: 1,
      deviceId: "device-1",
      targets: {
        "https://rakazo.example.com#space_1": {
          sourceId: "deleted-source",
          listing: { cursor: null, token: null, lastItem: null },
          changeToken: null,
          uploads: {},
        },
      },
    });
    vi.mocked(api.media.sources.pushItems).mockRejectedValueOnce(
      Object.assign(new Error("Not found"), { code: "NOT_FOUND" }),
    );
    await syncApplePhotos({ ...baseOptions(), helper, api, store, uploadChunk: vi.fn() });
    expect(api.media.sources.registerClient).toHaveBeenCalledTimes(1);
    expect(vi.mocked(api.media.sources.pushItems).mock.calls.at(-1)?.[0].sourceId).toBe("source-1");
  });

  it("stops before anything is sent when Photos access is denied", async () => {
    const { helper } = fakeHelper({ size: 2 });
    vi.mocked(helper.authorize).mockResolvedValueOnce("denied");
    const { api } = fakeApi();
    await expect(
      syncApplePhotos({
        ...baseOptions(),
        helper,
        api,
        store: memoryStore().store,
        uploadChunk: vi.fn(),
      }),
    ).rejects.toMatchObject({ code: "not_authorized" });
    expect(api.media.sources.registerClient).not.toHaveBeenCalled();
  });
});

describe("Apple Photos original upload", () => {
  const awaitingAssets = [
    asset("a1", "ASSET-00001/L0/001", "awaiting_upload"),
    asset("a2", "ASSET-00002/L0/001", "proxied"),
    asset("a3", "ASSET-00003/L0/001", "awaiting_upload"),
    asset("a4", "ASSET-00004/L0/001", "awaiting_upload"),
  ];

  it("uploads every awaiting original in chunks with two at a time and cleans up", async () => {
    const { helper, exports, stats } = fakeHelper({ size: 1 });
    const { api } = fakeApi({ assets: awaitingAssets, chunkBytes: 8 });
    const sent = new Map<string, Buffer[]>();
    const uploadChunk = vi.fn(async (uploadId: string, index: number, bytes: Uint8Array) => {
      const parts = sent.get(uploadId) ?? [];
      parts[index] = Buffer.from(bytes);
      sent.set(uploadId, parts);
    });
    const progress = vi.fn();

    const result = await syncApplePhotos({
      ...baseOptions(),
      helper,
      api,
      store: memoryStore().store,
      uploadChunk,
      onProgress: progress,
    });

    expect(result.uploaded).toBe(3);
    expect(
      vi
        .mocked(helper.exportOriginal)
        .mock.calls.map((call) => call[0])
        .sort(),
    ).toEqual(["ASSET-00001/L0/001", "ASSET-00003/L0/001", "ASSET-00004/L0/001"]);
    expect(stats.maxActiveExports).toBe(2);
    expect(Buffer.concat(sent.get("upload-a1")!).toString()).toBe(
      "original bytes of ASSET-00001/L0/001",
    );
    expect(sent.get("upload-a1")).toHaveLength(Math.ceil(36 / 8));
    expect(api.media.uploads.begin).toHaveBeenCalledWith(
      expect.objectContaining({
        assetId: "a1",
        sizeBytes: 36,
        sha256: sha("original bytes of ASSET-00001/L0/001"),
      }),
      expect.anything(),
    );
    expect(api.media.uploads.complete).toHaveBeenCalledTimes(3);
    expect(progress).toHaveBeenLastCalledWith({
      phase: "uploading",
      indexed: 1,
      uploadsDone: 3,
      uploadsTotal: 3,
    });
    for (const dir of exports) await expect(readdir(dir)).rejects.toThrow();
    await expect(readdir(tempRoot)).resolves.toEqual([]);
  });

  it("resumes an open upload and sends only the missing chunks", async () => {
    const { helper } = fakeHelper({ size: 1 });
    const contents = "original bytes of ASSET-00001/L0/001";
    const { api } = fakeApi({
      assets: [awaitingAssets[0]!],
      uploads: {
        "upload-old": {
          id: "upload-old",
          assetId: "a1",
          sizeBytes: Buffer.byteLength(contents),
          chunkBytes: 10,
          receivedChunks: [0, 2],
          status: "open",
        },
      },
    });
    const { store, current } = memoryStore({
      version: 1,
      deviceId: "device-1",
      targets: {
        "https://rakazo.example.com#space_1": {
          sourceId: "source-1",
          listing: null,
          changeToken: "tok",
          uploads: { a1: "upload-old" },
        },
      },
    });
    vi.mocked(helper.changes).mockResolvedValueOnce({
      token: "tok",
      changed: [],
      deleted: [],
      fullResyncRequired: false,
    });
    const uploadChunk = vi.fn(async () => {});

    await syncApplePhotos({ ...baseOptions(), helper, api, store, uploadChunk });

    expect(api.media.uploads.begin).not.toHaveBeenCalled();
    expect(
      uploadChunk.mock.calls.map((call) => [
        call[0],
        call[1],
        Buffer.from(call[2] as Uint8Array).toString(),
      ]),
    ).toEqual([
      ["upload-old", 1, contents.slice(10, 20)],
      ["upload-old", 3, contents.slice(30)],
    ]);
    expect(current().targets["https://rakazo.example.com#space_1"]?.uploads).toEqual({});
  });

  it("aborts on a checksum mismatch without starting an upload", async () => {
    const { helper } = fakeHelper({ size: 1 });
    vi.mocked(helper.exportOriginal).mockImplementationOnce(async (_id, destination) => {
      const file = path.join(destination, "IMG.MOV");
      await writeFile(file, "tampered");
      return { path: file, fileName: "IMG.MOV", sizeBytes: 8, sha256: sha("original") };
    });
    const { api } = fakeApi({ assets: [awaitingAssets[0]!] });
    const uploadChunk = vi.fn();

    await expect(
      syncApplePhotos({ ...baseOptions(), helper, api, store: memoryStore().store, uploadChunk }),
    ).rejects.toMatchObject({ code: "integrity" });
    expect(api.media.uploads.begin).not.toHaveBeenCalled();
    expect(uploadChunk).not.toHaveBeenCalled();
    await expect(readdir(tempRoot)).resolves.toEqual([]);
  });

  it("cancels a running upload", async () => {
    const { helper } = fakeHelper({ size: 1 });
    const { api } = fakeApi({ assets: [awaitingAssets[0]!], chunkBytes: 4 });
    const controller = new AbortController();
    const uploadChunk = vi.fn(
      async (_id: string, index: number, _bytes: Uint8Array, signal: AbortSignal) => {
        if (index === 1) controller.abort();
        signal.throwIfAborted();
      },
    );

    await expect(
      syncApplePhotos({
        ...baseOptions(),
        signal: controller.signal,
        helper,
        api,
        store: memoryStore().store,
        uploadChunk,
      }),
    ).rejects.toMatchObject({ code: "cancelled" });
    expect(uploadChunk).toHaveBeenCalledTimes(2);
    expect(api.media.uploads.complete).not.toHaveBeenCalled();
    await expect(readdir(tempRoot)).resolves.toEqual([]);
  });

  it("refuses to guess which Photos item an asset is", async () => {
    const { helper } = fakeHelper({ size: 1 });
    const { api } = fakeApi({ assets: [asset("a1", undefined, "awaiting_upload")] });
    await expect(
      syncApplePhotos({
        ...baseOptions(),
        helper,
        api,
        store: memoryStore().store,
        uploadChunk: vi.fn(),
      }),
    ).rejects.toMatchObject({ code: "unsupported_server" });
    expect(helper.exportOriginal).not.toHaveBeenCalled();
  });
});

describe("Apple Photos sync state file", () => {
  it("keeps a stable device id across launches", async () => {
    const dir = await mkdtemp(path.join(tmpdir(), "rakazo-photos-state-"));
    try {
      const store = createPhotosSyncFileStore(dir, () => "device-a");
      const first = await store.read();
      expect(first.deviceId).toBe("device-a");
      first.targets.x = { sourceId: "s", listing: null, changeToken: "t", uploads: {} };
      await store.write(first);
      const reopened = await createPhotosSyncFileStore(dir, () => "device-b").read();
      expect(reopened).toEqual(first);
      expect(await readFile(path.join(dir, "media-photos-sync.json"), "utf8")).toContain(
        "device-a",
      );
    } finally {
      await rm(dir, { recursive: true, force: true });
    }
  });

  it("drops unreadable state and malformed targets", () => {
    expect(parsePhotosSyncState("{")).toBeNull();
    expect(
      parsePhotosSyncState(JSON.stringify({ version: 2, deviceId: "d", targets: {} })),
    ).toBeNull();
    expect(
      parsePhotosSyncState(
        JSON.stringify({
          version: 1,
          deviceId: "d",
          targets: {
            good: { sourceId: "s", listing: null, changeToken: null, uploads: {} },
            bad: { sourceId: 4, listing: null, changeToken: null, uploads: {} },
            badListing: { sourceId: "s", listing: { cursor: 3 }, changeToken: null, uploads: {} },
          },
        }),
      )?.targets,
    ).toEqual({ good: { sourceId: "s", listing: null, changeToken: null, uploads: {} } });
  });
});

describe("chunk uploader", () => {
  it("PUTs raw bytes with the session and space", async () => {
    const fetch = vi.fn(async () => new Response(null, { status: 204 }));
    const upload = createChunkUploader({
      origin: "https://rakazo.example.com",
      spaceId: "space_1",
      fetch,
    });
    const signal = new AbortController().signal;
    await upload("up/1", 3, new Uint8Array([1, 2, 3]), signal);
    expect(fetch).toHaveBeenCalledWith(
      "https://rakazo.example.com/api/media/uploads/up%2F1/chunks/3",
      expect.objectContaining({
        method: "PUT",
        credentials: "include",
        redirect: "error",
        signal,
        headers: { "content-type": "application/octet-stream", "x-rakazo-space-id": "space_1" },
      }),
    );
  });

  it("rejects failed chunks and non-origin targets", async () => {
    const fetch = vi.fn(async () => new Response(null, { status: 409 }));
    const upload = createChunkUploader({
      origin: "https://rakazo.example.com",
      spaceId: null,
      fetch,
    });
    await expect(
      upload("u", 0, new Uint8Array(), new AbortController().signal),
    ).rejects.toMatchObject({
      code: "upload_failed",
    });
    expect(() =>
      createChunkUploader({ origin: "https://rakazo.example.com/rpc", spaceId: null, fetch }),
    ).toThrow();
    expect(() => createChunkUploader({ origin: "file:///etc", spaceId: null, fetch })).toThrow();
  });
});

describe("runPool", () => {
  it("bounds concurrency and reports the first failure", async () => {
    let active = 0;
    let max = 0;
    const seen: number[] = [];
    await expect(
      runPool([1, 2, 3, 4, 5], 2, new AbortController().signal, async (item, signal) => {
        active += 1;
        max = Math.max(max, active);
        await new Promise((resolve) => setTimeout(resolve, 5));
        active -= 1;
        if (item === 2) throw new Error("boom");
        signal.throwIfAborted();
        seen.push(item);
      }),
    ).rejects.toThrow("boom");
    expect(max).toBe(2);
    expect(seen).not.toContain(4);
  });
});