import {
  type ApiResponse,
  count,
  createUser,
  db,
  del,
  formWithFile,
  get,
  insertCategory,
  insertDump,
  insertPlaylist,
  PNG,
  post,
  put,
  test,
  TEST_DIR,
} from "../helpers.ts";
import type { PaginatedData } from "../../../shared/api.ts";
import {
  comparePlaylists,
  type Playlist,
  PLAYLIST_SORTS,
  type PlaylistMembership,
  type PlaylistWithDumps,
} from "../../../shared/playlist.ts";
import { assert, assertEquals, assertMatch } from "@std/assert";

function ids(res: ApiResponse<PlaylistWithDumps>): string[] {
  return res.data.dumps.map((d) => d.id);
}

test("POST /api/playlists creates; GET finds it by id, or by path under its owner", async () => {
  const user = await createUser();
  const res = await post<Playlist>("/api/playlists", {
    auth: user.auth,
    json: { title: "Road Trip", description: "songs", isPublic: true },
  });
  assertEquals(res.status, 201);
  const { id, slug } = res.data;
  assertEquals(slug, "road-trip");
  assertEquals(res.data.ownerUsername, user.username);
  assertEquals(
    (await get<PlaylistWithDumps>(`/api/playlists/${id}`)).data.title,
    "Road Trip",
  );
  assertEquals((await get(`/api/playlists/${slug}`)).status, 404);
  const bySlug = await get<PlaylistWithDumps>(
    `/api/users/@${user.username}/playlists/${slug}`,
  );
  assertEquals(bySlug.data.id, id);
  assertEquals(bySlug.data.ownerUsername, user.username);
  assertEquals(bySlug.data.dumps, []);
  assertEquals(
    (await post("/api/playlists", { auth: user.auth, json: { title: "" } }))
      .status,
    400,
  );
  assertEquals(
    (await post("/api/playlists", { json: { title: "x", isPublic: true } }))
      .status,
    401,
  );
});

test("private playlists are the owner's alone", async () => {
  const owner = await createUser();
  const other = await createUser();
  const { id } = insertPlaylist({ userId: owner.id, isPublic: false });
  assertEquals((await get(`/api/playlists/${id}`)).status, 404);
  assertEquals(
    (await get(`/api/playlists/${id}`, { auth: other.auth })).status,
    404,
  );
  assertEquals(
    (await get(`/api/playlists/${id}`, { auth: owner.auth })).status,
    200,
  );
  insertPlaylist({ userId: owner.id });
  const path = `/api/users/@${owner.username}/playlists`;
  assertEquals((await get<PaginatedData<Playlist>>(path)).data.items.length, 1);
  assertEquals(
    (await get<PaginatedData<Playlist>>(path, { auth: owner.auth })).data.items
      .length,
    2,
  );
});

test("adding dumps: newest on top, no duplicates, only dumps you can see", async () => {
  const owner = await createUser();
  const other = await createUser();
  const { id } = insertPlaylist({ userId: owner.id });
  const a = insertDump({ userId: owner.id, title: "a" });
  const b = insertDump({ userId: other.id, title: "b" });
  const theirs = insertDump({ userId: other.id, isPrivate: true });

  assertEquals(
    (await post(`/api/playlists/${id}/dumps/${a.id}`, { auth: owner.auth }))
      .status,
    204,
  );
  assertEquals(
    (await post(`/api/playlists/${id}/dumps/${b.id}`, { auth: owner.auth }))
      .status,
    204,
  );
  assertEquals(ids(await get(`/api/playlists/${id}`)), [b.id, a.id]);
  assertEquals(
    (await post(`/api/playlists/${id}/dumps/${a.id}`, { auth: owner.auth }))
      .status,
    409,
  );
  assertEquals(
    (await post(`/api/playlists/${id}/dumps/${theirs.id}`, {
      auth: owner.auth,
    })).status,
    404,
  );
  assertEquals(
    (await post(`/api/playlists/${id}/dumps/${crypto.randomUUID()}`, {
      auth: owner.auth,
    }))
      .status,
    404,
  );
  assertEquals(
    (await post(`/api/playlists/${id}/dumps/${a.id}`, { auth: other.auth }))
      .status,
    403,
  );
  assertEquals(
    (await get<PlaylistWithDumps>(`/api/playlists/${id}`)).data.dumpCount,
    2,
  );
});

test("a public playlist hides its private dumps from everyone but their owner", async () => {
  const owner = await createUser();
  const { id } = insertPlaylist({ userId: owner.id });
  const pub = insertDump({ userId: owner.id });
  const priv = insertDump({ userId: owner.id, isPrivate: true });
  for (const d of [pub, priv]) {
    await post(`/api/playlists/${id}/dumps/${d.id}`, { auth: owner.auth });
  }
  assertEquals(ids(await get(`/api/playlists/${id}`)), [pub.id]);
  assertEquals(
    ids(await get(`/api/playlists/${id}`, { auth: owner.auth })).length,
    2,
  );
});

test("a playlist's dumpCount is of the dumps the viewer may see", async () => {
  const owner = await createUser();
  const author = await createUser();
  const pl = insertPlaylist({ userId: owner.id, title: "Counted banana" });
  const pub = insertDump({ userId: owner.id });
  const mine = insertDump({ userId: owner.id, isPrivate: true });
  // Someone else's, gone private after it was added: its owner no longer
  // sees it there, and neither does its poster.
  const theirs = insertDump({ userId: author.id, isPrivate: true });
  for (const [i, d] of [pub, mine, theirs].entries()) {
    db.prepare(
      `INSERT INTO playlist_dumps (playlist_id, dump_id, position, added_at)
       VALUES (?, ?, ?, ?);`,
    ).run(pl.id, d.id, i, new Date().toISOString());
  }
  await put(`/api/me/follow/playlists/${pl.id}`, { auth: author.auth });

  const lists = [
    "/api/playlists",
    `/api/users/@${owner.username}/playlists`,
    `/api/users/@${author.username}/follow/playlists`,
  ];
  for (
    const [auth, expected] of [
      [owner.auth, 2],
      [author.auth, 1],
      [undefined, 1],
    ] as const
  ) {
    for (const url of lists) {
      const { items } = (await get<PaginatedData<Playlist>>(url, { auth }))
        .data;
      assertEquals(items.map((p) => p.dumpCount), [expected], url);
    }
    assertEquals(
      (await get<{ playlists: Playlist[] }>("/api/search?q=banana", { auth }))
        .data.playlists.map((p) => p.dumpCount),
      [expected],
    );
    assertEquals(
      (await get<Playlist[]>(`/api/dumps/${pub.id}/playlists`, { auth })).data
        .map((p) => p.dumpCount),
      [expected],
    );
    const page = await get<PlaylistWithDumps>(`/api/playlists/${pl.id}`, {
      auth,
    });
    assertEquals(page.data.dumpCount, expected);
    assertEquals(ids(page).length, expected);
  }
  assertEquals(
    (await get<PlaylistMembership[]>(`/api/me/playlists?contains=${pub.id}`, {
      auth: owner.auth,
    })).data.map((m) => [m.hasDump, m.playlist.dumpCount]),
    [[true, 2]],
  );
  // An edit answers with the editor's count.
  assertEquals(
    (await put<Playlist>(`/api/playlists/${pl.id}`, {
      auth: owner.auth,
      json: { title: "Counted" },
    })).data.dumpCount,
    2,
  );
});

test("reorder: must name exactly the current members", async () => {
  const owner = await createUser();
  const { id } = insertPlaylist({ userId: owner.id });
  const [a, b, c] = [1, 2, 3].map(() => insertDump({ userId: owner.id }));
  for (const d of [a, b, c]) {
    await post(`/api/playlists/${id}/dumps/${d.id}`, { auth: owner.auth });
  }
  const order = [a.id, c.id, b.id];
  assertEquals(
    (await put(`/api/playlists/${id}/order`, {
      auth: owner.auth,
      json: { dumpIds: order },
    }))
      .status,
    200,
  );
  assertEquals(ids(await get(`/api/playlists/${id}`)), order);
  for (const dumpIds of [[a.id, b.id], [a.id, b.id, crypto.randomUUID()]]) {
    assertEquals(
      (await put(`/api/playlists/${id}/order`, {
        auth: owner.auth,
        json: { dumpIds },
      }))
        .status,
      400,
      JSON.stringify(dumpIds),
    );
  }
  // A dump added after reordering still lands on top.
  const d = insertDump({ userId: owner.id });
  await post(`/api/playlists/${id}/dumps/${d.id}`, { auth: owner.auth });
  assertEquals(ids(await get(`/api/playlists/${id}`))[0], d.id);
});

test("reorder: a list naming a member twice is not the current members", async () => {
  const owner = await createUser();
  const { id } = insertPlaylist({ userId: owner.id });
  const [a, b] = [1, 2].map(() => insertDump({ userId: owner.id }));
  for (const d of [a, b]) {
    await post(`/api/playlists/${id}/dumps/${d.id}`, { auth: owner.auth });
  }
  const res = await put(`/api/playlists/${id}/order`, {
    auth: owner.auth,
    json: { dumpIds: [a.id, b.id, a.id] },
  });
  assertEquals(res.status, 400);
});

test("removing a dump; updating; deleting", async () => {
  const owner = await createUser();
  const other = await createUser();
  const mod = await createUser({ role: "moderator" });
  const { id } = insertPlaylist({ userId: owner.id, title: "Old" });
  const a = insertDump({ userId: owner.id });
  await post(`/api/playlists/${id}/dumps/${a.id}`, { auth: owner.auth });
  assertEquals(
    (await del(`/api/playlists/${id}/dumps/${a.id}`, { auth: other.auth }))
      .status,
    403,
  );
  assertEquals(
    (await del(`/api/playlists/${id}/dumps/${a.id}`, { auth: owner.auth }))
      .status,
    204,
  );
  assertEquals(ids(await get(`/api/playlists/${id}`)), []);

  assertEquals(
    (await put(`/api/playlists/${id}`, {
      auth: other.auth,
      json: { title: "x" },
    })).status,
    403,
  );
  const updated = await put<Playlist>(`/api/playlists/${id}`, {
    auth: owner.auth,
    json: { title: "New", description: "d", isPublic: false },
  });
  assertEquals(updated.data.title, "New");
  // A new title never changes the slug by itself; a slug sent does.
  assertEquals(updated.data.slug, "old");
  assertEquals(updated.data.isPublic, false);
  const reslugged = await put<Playlist>(`/api/playlists/${id}`, {
    auth: owner.auth,
    json: { slug: "new" },
  });
  assertEquals(reslugged.data.slug, "new");
  assertEquals(
    (await get<PlaylistWithDumps>(
      `/api/users/@${owner.username}/playlists/old`,
      { auth: owner.auth },
    )).data.slug,
    "new",
  );
  assertEquals(
    (await put(`/api/playlists/${id}`, {
      auth: owner.auth,
      json: { slug: "Bad slug" },
    })).status,
    400,
  );
  const cleared = await put<Playlist>(`/api/playlists/${id}`, {
    auth: owner.auth,
    json: { description: null },
  });
  assertEquals(cleared.data.description, undefined);
  assertEquals(cleared.data.title, "New");

  assertEquals(
    (await del(`/api/playlists/${id}`, { auth: other.auth })).status,
    403,
  );
  assertEquals(
    (await del(`/api/playlists/${id}`, { auth: mod.auth })).status,
    204,
  );
  assertEquals(
    (await get(`/api/playlists/${id}`, { auth: owner.auth })).status,
    404,
  );
  assertEquals(count(`SELECT COUNT(*) as n FROM playlist_dumps;`), 0);
});

test("memberships: which of my playlists hold this dump", async () => {
  const owner = await createUser();
  const other = await createUser();
  const p1 = insertPlaylist({ userId: owner.id, title: "has" });
  insertPlaylist({ userId: owner.id, title: "hasnt" });
  insertPlaylist({ userId: other.id, title: "theirs" });
  const d = insertDump({ userId: owner.id });
  await post(`/api/playlists/${p1.id}/dumps/${d.id}`, { auth: owner.auth });
  const res = await get<PlaylistMembership[]>(
    `/api/me/playlists?contains=${d.id}`,
    {
      auth: owner.auth,
    },
  );
  const byTitle = Object.fromEntries(
    res.data.map((
      m: { playlist: { title: string }; hasDump: boolean },
    ) => [
      m.playlist.title,
      m.hasDump,
    ]),
  );
  assertEquals(byTitle, { has: true, hasnt: false });
});

test("adding to a followed public playlist notifies followers, private dumps excepted", async () => {
  const owner = await createUser();
  const follower = await createUser();
  const { id } = insertPlaylist({ userId: owner.id, title: "Mix" });
  await put(`/api/me/follow/playlists/${id}`, { auth: follower.auth });
  db.exec(`DELETE FROM notifications;`); // the follow notified the owner
  const priv = insertDump({ userId: owner.id, isPrivate: true });
  await post(`/api/playlists/${id}/dumps/${priv.id}`, { auth: owner.auth });
  assertEquals(count(`SELECT COUNT(*) as n FROM notifications;`), 0);
  const pub = insertDump({ userId: owner.id, title: "Song" });
  await post(`/api/playlists/${id}/dumps/${pub.id}`, { auth: owner.auth });
  const note = db.prepare(`SELECT user_id, type, data FROM notifications;`)
    .get() as {
      user_id: string;
      type: string;
      data: string;
    };
  assertEquals(note.user_id, follower.id);
  assertEquals(note.type, "playlist_dump_added");
  assertEquals(JSON.parse(note.data), {
    dumpId: pub.id,
    dumpTitle: "Song",
    playlistId: id,
    playlistTitle: "Mix",
  });
});

test("a playlist going public notifies its followers of the public dumps added meanwhile", async () => {
  const owner = await createUser();
  const follower = await createUser();
  const { id } = insertPlaylist({ userId: owner.id, title: "Mix" });
  await put(`/api/me/follow/playlists/${id}`, { auth: follower.auth });
  const before = insertDump({ userId: owner.id, title: "Before" });
  await post(`/api/playlists/${id}/dumps/${before.id}`, { auth: owner.auth });
  db.prepare(`DELETE FROM notifications WHERE user_id = ?;`).run(owner.id);
  const setPublic = (isPublic: boolean) =>
    put(`/api/playlists/${id}`, { auth: owner.auth, json: { isPublic } });

  await setPublic(false);
  const during = insertDump({ userId: owner.id, title: "During" });
  const priv = insertDump({ userId: owner.id, isPrivate: true });
  for (const d of [during, priv]) {
    await post(`/api/playlists/${id}/dumps/${d.id}`, { auth: owner.auth });
  }
  assertEquals(count(`SELECT COUNT(*) as n FROM notifications;`), 1);
  await setPublic(true);
  const titles = (db.prepare(
    `SELECT data FROM notifications WHERE user_id = ? ORDER BY created_at;`,
  ).all(follower.id) as { data: string }[]).map((n) =>
    JSON.parse(n.data).dumpTitle
  );
  assertEquals(titles, ["Before", "During"]);
});

test("playlist covers: upload and serve", async () => {
  const owner = await createUser();
  const other = await createUser();
  const { id } = insertPlaylist({ userId: owner.id });
  assertEquals((await get(`/api/playlists/${id}/cover`)).status, 404);
  assertEquals(
    (await put(`/api/playlists/${id}/cover`, {
      auth: other.auth,
      form: formWithFile(PNG),
    }))
      .status,
    403,
  );
  const res = await put<Playlist>(`/api/playlists/${id}/cover`, {
    auth: owner.auth,
    form: formWithFile(PNG),
  });
  assertEquals(res.status, 200);
  assertEquals(res.data.imageMime, "image/png");
  // A new cover counts as an edit, so image URLs versioned on it change.
  assert(res.data.updatedAt);
  const served = await get(`/api/playlists/${id}/cover`);
  assertEquals(served.status, 200);
  assertEquals(served.bytes, PNG);
});

test("playlist covers: a private playlist's cover only for its owner's media token", async () => {
  const owner = await createUser();
  const other = await createUser();
  const { id } = insertPlaylist({ userId: owner.id, isPublic: false });
  await put(`/api/playlists/${id}/cover`, {
    auth: owner.auth,
    form: formWithFile(PNG),
  });
  assertEquals((await get(`/api/playlists/${id}/cover`)).status, 404);
  assertEquals(
    (await get(`/api/playlists/${id}/cover?token=${other.mediaToken}`)).status,
    404,
  );
  assertEquals(
    (await get(`/api/playlists/${id}/cover?token=garbage`)).status,
    404,
  );
  const served = await get(
    `/api/playlists/${id}/cover?token=${owner.mediaToken}`,
  );
  assertEquals(served.status, 200);
  assertEquals(served.bytes, PNG);
  assertMatch(served.headers.get("cache-control") ?? "", /^private/);
});

test("playlist covers: a failed write leaves the row and the old cover alone", async () => {
  const owner = await createUser();
  const { id } = insertPlaylist({ userId: owner.id });
  const dir = `${TEST_DIR}/uploads/playlist-images`;
  const row = () =>
    db.prepare(`SELECT image_mime, updated_at FROM playlists WHERE id = ?;`)
      .get(id) as { image_mime: string | null; updated_at: string | null };

  // No cover yet, and the write fails (a directory sits where the file goes):
  // the playlist mustn't claim a cover it hasn't got.
  await Deno.mkdir(`${dir}/${id}/blocker`, { recursive: true });
  try {
    const failed = await put(`/api/playlists/${id}/cover`, {
      auth: owner.auth,
      form: formWithFile(PNG),
    });
    assertEquals(failed.status, 500);
    assertEquals(row(), { image_mime: null, updated_at: null });
    assertEquals((await get(`/api/playlists/${id}/cover`)).status, 404);
  } finally {
    await Deno.remove(`${dir}/${id}`, { recursive: true });
  }

  // With a cover in place, a failed replacement keeps serving the old one
  // under the old version, and leaves no stray temporary file behind.
  await put(`/api/playlists/${id}/cover`, {
    auth: owner.auth,
    form: formWithFile(PNG),
  });
  const before = row();
  await Deno.chmod(dir, 0o555);
  try {
    const failed = await put(`/api/playlists/${id}/cover`, {
      auth: owner.auth,
      form: formWithFile(new Uint8Array([...PNG, 0])),
    });
    assertEquals(failed.status, 500);
  } finally {
    await Deno.chmod(dir, 0o755);
  }
  assertEquals(row(), before);
  assertEquals((await get(`/api/playlists/${id}/cover`)).bytes, PNG);
  const left = [...Deno.readDirSync(dir)]
    .map((e) => e.name)
    .filter((name) => name.startsWith(id));
  assertEquals(left, [id]);
});

test("playlist covers: a replaced cover is served under the new version", async () => {
  const owner = await createUser();
  const { id } = insertPlaylist({ userId: owner.id });
  const first = await put<Playlist>(`/api/playlists/${id}/cover`, {
    auth: owner.auth,
    form: formWithFile(PNG),
  });
  await new Promise((r) => setTimeout(r, 5)); // a distinct updated_at
  const other = new Uint8Array([...PNG, 1, 2, 3]);
  const second = await put<Playlist>(`/api/playlists/${id}/cover`, {
    auth: owner.auth,
    form: formWithFile(other),
  });
  assert(second.data.updatedAt !== first.data.updatedAt);
  assertEquals((await get(`/api/playlists/${id}/cover`)).bytes, other);
});

test("reorder: someone else's dump that went private keeps its slot", async () => {
  const owner = await createUser();
  const author = await createUser();
  const { id } = insertPlaylist({ userId: owner.id });
  const a = insertDump({ userId: owner.id });
  const theirs = insertDump({ userId: author.id });
  const b = insertDump({ userId: owner.id });
  // Each add goes on top: the order is b, theirs, a.
  for (const d of [a, theirs, b]) {
    await post(`/api/playlists/${id}/dumps/${d.id}`, { auth: owner.auth });
  }
  await put(`/api/dumps/${theirs.id}`, {
    auth: author.auth,
    json: { isPrivate: true },
  });
  // The owner can't see it, so can't name it: what they see is theirs to order.
  assertEquals(ids(await get(`/api/playlists/${id}`, { auth: owner.auth })), [
    b.id,
    a.id,
  ]);
  const res = await put(`/api/playlists/${id}/order`, {
    auth: owner.auth,
    json: { dumpIds: [a.id, b.id] },
  });
  assertEquals(res.status, 200);
  assertEquals(ids(await get(`/api/playlists/${id}`, { auth: owner.auth })), [
    a.id,
    b.id,
  ]);
  // The hidden one hasn't moved, and comes back where it was if made public.
  await put(`/api/dumps/${theirs.id}`, {
    auth: author.auth,
    json: { isPrivate: false },
  });
  assertEquals(ids(await get(`/api/playlists/${id}`)), [a.id, theirs.id, b.id]);
  // Naming a hidden id is still not the list the requester sees.
  await put(`/api/dumps/${theirs.id}`, {
    auth: author.auth,
    json: { isPrivate: true },
  });
  assertEquals(
    (await put(`/api/playlists/${id}/order`, {
      auth: owner.auth,
      json: { dumpIds: [a.id, theirs.id, b.id] },
    })).status,
    400,
  );
});

test("reorder: a moderator orders around the owner's private dumps", async () => {
  const owner = await createUser();
  const mod = await createUser({ role: "moderator" });
  const { id } = insertPlaylist({ userId: owner.id });
  const a = insertDump({ userId: owner.id });
  const priv = insertDump({ userId: owner.id, isPrivate: true });
  const b = insertDump({ userId: owner.id });
  for (const d of [a, priv, b]) {
    await post(`/api/playlists/${id}/dumps/${d.id}`, { auth: owner.auth });
  }
  assertEquals(ids(await get(`/api/playlists/${id}`, { auth: mod.auth })), [
    b.id,
    a.id,
  ]);
  assertEquals(
    (await put(`/api/playlists/${id}/order`, {
      auth: mod.auth,
      json: { dumpIds: [a.id, b.id] },
    })).status,
    200,
  );
  assertEquals(ids(await get(`/api/playlists/${id}`, { auth: owner.auth })), [
    a.id,
    priv.id,
    b.id,
  ]);
});

test("playlist categories: filed on creation, replaced on update, dump categories refused", async () => {
  const user = await createUser();
  const mixes = insertCategory({ slug: "mixes", kind: "playlist" });
  const live = insertCategory({ slug: "live", kind: "playlist" });
  const music = insertCategory({ slug: "music" });

  const refused = await post("/api/playlists", {
    auth: user.auth,
    json: { title: "Wrong", isPublic: true, categoryIds: [music] },
  });
  assertEquals(refused.status, 400);
  assertEquals(count(`SELECT COUNT(*) as n FROM playlists;`), 0);
  assertEquals(
    (await post("/api/playlists", {
      auth: user.auth,
      json: { title: "Bad", isPublic: true, categoryIds: "mixes" },
    })).status,
    400,
  );

  const created = await post<Playlist>("/api/playlists", {
    auth: user.auth,
    json: { title: "Mix", isPublic: true, categoryIds: [mixes, mixes] },
  });
  assertEquals(created.status, 201);
  assertEquals(created.data.categoryIds, [mixes]);
  assertEquals(
    (await get<Playlist>(`/api/playlists/${created.data.id}`)).data
      .categoryIds,
    [mixes],
  );

  const id = created.data.id;
  assertEquals(
    (await put(`/api/playlists/${id}`, {
      auth: user.auth,
      json: { categoryIds: [music] },
    })).status,
    400,
  );
  const updated = await put<Playlist>(`/api/playlists/${id}`, {
    auth: user.auth,
    json: { categoryIds: [live] },
  });
  assertEquals(updated.data.categoryIds, [live]);
  // A change of anything else keeps them.
  const renamed = await put<Playlist>(`/api/playlists/${id}`, {
    auth: user.auth,
    json: { title: "Live mix" },
  });
  assertEquals(renamed.data.categoryIds, [live]);
  const cleared = await put<Playlist>(`/api/playlists/${id}`, {
    auth: user.auth,
    json: { categoryIds: [] },
  });
  assertEquals(cleared.data.categoryIds, []);
});

test("GET /api/playlists: every public playlist, by category", async () => {
  const owner = await createUser();
  const other = await createUser();
  const mixes = insertCategory({ slug: "mixes", kind: "playlist" });
  insertCategory({ slug: "music" });
  const a = insertPlaylist({ userId: owner.id, title: "A" });
  insertPlaylist({ userId: other.id, title: "B" });
  const hidden = insertPlaylist({
    userId: owner.id,
    title: "Hidden",
    isPublic: false,
  });
  db.prepare(`UPDATE playlists SET created_at = ? WHERE id = ?;`)
    .run("2026-01-01T00:00:00.000Z", a.id);
  for (const p of [a, hidden]) {
    db.prepare(
      `INSERT INTO playlist_categories (playlist_id, category_id) VALUES (?, ?);`,
    ).run(p.id, mixes);
  }

  const all = await get<PaginatedData<Playlist>>("/api/playlists", {
    auth: owner.auth,
  });
  assertEquals(all.data.items.map((p) => p.title), ["B", "A"]);
  assertEquals(all.data.items[1].categoryIds, [mixes]);
  assertEquals(
    (await get<PaginatedData<Playlist>>("/api/playlists?limit=1")).data
      .hasMore,
    true,
  );
  assertEquals(
    (await get<PaginatedData<Playlist>>("/api/playlists?category=mixes")).data
      .items.map((p) => p.id),
    [a.id],
  );
  // A dump category's slug names no playlist category.
  assertEquals((await get("/api/playlists?category=music")).status, 404);
  assertEquals((await get("/api/playlists?category=nope")).status, 404);
});

test("GET /api/users/:key/playlists?category=: their playlists in one category", async () => {
  const owner = await createUser();
  const mixes = insertCategory({ slug: "mixes", kind: "playlist" });
  const a = insertPlaylist({ userId: owner.id, title: "A" });
  insertPlaylist({ userId: owner.id, title: "B" });
  db.prepare(
    `INSERT INTO playlist_categories (playlist_id, category_id) VALUES (?, ?);`,
  ).run(a.id, mixes);

  const url = `/api/users/${owner.id}/playlists`;
  assertEquals(
    (await get<PaginatedData<Playlist>>(url)).data.items.length,
    2,
  );
  assertEquals(
    (await get<PaginatedData<Playlist>>(`${url}?category=mixes`)).data.items
      .map((p) => p.id),
    [a.id],
  );
  assertEquals(
    (await get<PaginatedData<Playlist>>(`${url}?category=nope`)).data.items,
    [],
  );
});

test("?sort=: by the last dump added, by creation or by dumps, as the viewer sees them", async () => {
  const owner = await createUser();
  const made = (title: string, createdAt: string) => {
    const { id } = insertPlaylist({ userId: owner.id, title });
    db.prepare(`UPDATE playlists SET created_at = ? WHERE id = ?;`)
      .run(createdAt, id);
    return id;
  };
  const add = (playlistId: string, addedAt: string, isPrivate = false) =>
    db.prepare(
      `INSERT INTO playlist_dumps (playlist_id, dump_id, position, added_at)
       VALUES (?, ?, 0, ?);`,
    ).run(playlistId, insertDump({ userId: owner.id, isPrivate }).id, addedAt);
  const a = made("A", "2026-01-01T00:00:00.000Z");
  const b = made("B", "2026-02-01T00:00:00.000Z");
  const c = made("C", "2026-03-01T00:00:00.000Z");
  add(a, "2026-04-01T00:00:00.000Z");
  add(b, "2026-02-10T00:00:00.000Z");
  add(b, "2026-02-11T00:00:00.000Z");
  // Only the owner sees it: to anyone else, C is empty and as it was made.
  add(c, "2026-05-01T00:00:00.000Z", true);

  type Auth = typeof owner.auth;
  const list = async (query: string, auth?: Auth) =>
    (await get<PaginatedData<Playlist>>(query, { auth })).data.items;
  const titles = async (query: string, auth?: Auth) =>
    (await list(query, auth)).map((p) => p.title);

  for (
    const url of ["/api/playlists", `/api/users/${owner.id}/playlists`]
  ) {
    assertEquals(await titles(`${url}?sort=updated`), ["A", "C", "B"], url);
    assertEquals(await titles(`${url}?sort=new`), ["C", "B", "A"], url);
    assertEquals(await titles(`${url}?sort=dumps`), ["B", "A", "C"], url);
    assertEquals(
      await titles(`${url}?sort=updated`, owner.auth),
      ["C", "A", "B"],
      url,
    );
    // A and C hold one dump each to their owner: the newer goes first.
    assertEquals(
      await titles(`${url}?sort=dumps`, owner.auth),
      ["B", "C", "A"],
      url,
    );
    // The first order is the default, which an unknown one falls back to.
    assertEquals(await titles(url), ["A", "C", "B"], url);
    assertEquals(await titles(`${url}?sort=nope`), ["A", "C", "B"], url);
    assertEquals(await titles(`${url}?sort=new&limit=1&page=2`), ["B"], url);
  }

  const dates = (await list("/api/playlists?sort=new")).map((p) =>
    p.lastDumpAt
  );
  assertEquals(dates, [
    undefined,
    "2026-02-11T00:00:00.000Z",
    "2026-04-01T00:00:00.000Z",
  ] as unknown[]);
  assertEquals(
    (await get<PlaylistWithDumps>(`/api/playlists/${c}`, { auth: owner.auth }))
      .data.lastDumpAt as unknown,
    "2026-05-01T00:00:00.000Z",
  );
  assertEquals(
    (await get<PlaylistWithDumps>(`/api/playlists/${c}`)).data.lastDumpAt,
    undefined,
  );
});

test("comparePlaylists orders playlists as the API's ?sort= pages them", async () => {
  const owner = await createUser();
  // Ties of every kind: dates and counts shared by several playlists.
  for (let i = 0; i < 8; i++) {
    const { id } = insertPlaylist({ userId: owner.id, title: `P${i}` });
    db.prepare(`UPDATE playlists SET created_at = ? WHERE id = ?;`)
      .run(`2026-01-0${1 + i}T00:00:00.000Z`, id);
    for (let n = 0; n < i % 3; n++) {
      db.prepare(
        `INSERT INTO playlist_dumps (playlist_id, dump_id, position, added_at)
         VALUES (?, ?, ?, ?);`,
      ).run(
        id,
        insertDump({ userId: owner.id }).id,
        n,
        `2026-02-0${1 + ((i * 5 + n) % 9)}T00:00:00.000Z`,
      );
    }
  }
  for (const sort of PLAYLIST_SORTS) {
    const { items } = (await get<PaginatedData<Playlist>>(
      `/api/playlists?sort=${sort}`,
    )).data;
    // The dates come as strings over the wire.
    const playlists = items.map((p) => ({
      ...p,
      createdAt: new Date(p.createdAt),
      lastDumpAt: p.lastDumpAt && new Date(p.lastDumpAt),
    }));
    assertEquals(
      playlists.toSorted(comparePlaylists(sort)).map((p) => p.title),
      items.map((p) => p.title),
      sort,
    );
  }
});