Jellyfin Integration. Assisted by Claude Fable 5.

src/music/jellyfin.ts

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+import { readFileSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import crypto from "node:crypto";
+import axios, { type AxiosError, type AxiosInstance } from "axios";
+import type { JellyfinConfig } from "../data/config.js";
+import type { Logger } from "../logger.js";
+import type {
+  MusicProvider,
+  Song,
+  SongUrlResult,
+  Playlist,
+  PlaylistDetail,
+  LyricLine,
+  SearchResult,
+  QrCodeResult,
+  AuthStatus,
+  Album,
+} from "./provider.js";
+
+const __dirname = dirname(fileURLToPath(import.meta.url));
+
+/** 1 tick = 100 ns → 10,000,000 ticks = 1 second (Jellyfin RunTimeTicks / lyric Start). */
+export const TICKS_PER_SECOND = 10_000_000;
+
+export function ticksToSeconds(ticks: number | null | undefined): number {
+  if (typeof ticks !== "number" || !Number.isFinite(ticks)) return 0;
+  return ticks / TICKS_PER_SECOND;
+}
+
+const CLIENT_NAME = "TSMusicBot";
+
+/** Best-effort package version for the MediaBrowser auth header. */
+const PKG_VERSION = (() => {
+  try {
+    const pkg = JSON.parse(
+      readFileSync(join(__dirname, "..", "..", "package.json"), "utf-8"),
+    ) as { version?: string };
+    return pkg.version ?? "0.0.0";
+  } catch {
+    return "0.0.0";
+  }
+})();
+
+// Jellyfin quality tiers replace the NetEase labels for this source. "direct"
+// (default) streams the original file — the bot re-encodes to Opus anyway, so
+// this is max quality. The transcode tiers exist for remote/low-bandwidth
+// Jellyfin servers.
+export const JELLYFIN_QUALITY_LEVELS = [
+  { value: "direct", label: "原始直传 Direct", bitrate: 0 },
+  { value: "320", label: "320kbps 转码", bitrate: 320 },
+  { value: "192", label: "192kbps 转码", bitrate: 192 },
+  { value: "128", label: "128kbps 转码", bitrate: 128 },
+] as const;
+
+/** Subset of Jellyfin's BaseItemDto that this provider consumes. */
+export interface JellyfinItem {
+  Id: string;
+  Name?: string;
+  Artists?: string[];
+  AlbumArtist?: string;
+  Album?: string;
+  AlbumId?: string;
+  AlbumPrimaryImageTag?: string;
+  RunTimeTicks?: number;
+  ImageTags?: { Primary?: string };
+  ChildCount?: number;
+  SongCount?: number;
+  Overview?: string;
+}
+
+/**
+ * Primary cover art URL for an item; falls back to the parent album's primary
+ * image (AlbumPrimaryImageTag) and finally to "" (the UI renders a placeholder
+ * for missing art). The api_key query param authenticates browser <img> loads
+ * and the TS-avatar download alike.
+ */
+export function buildCoverUrl(baseUrl: string, apiKey: string, item: JellyfinItem): string {
+  if (!baseUrl) return "";
+  const key = apiKey ? `&api_key=${encodeURIComponent(apiKey)}` : "";
+  if (item.ImageTags?.Primary) {
+    return `${baseUrl}/Items/${item.Id}/Images/Primary?maxWidth=512&tag=${item.ImageTags.Primary}${key}`;
+  }
+  if (item.AlbumId && item.AlbumPrimaryImageTag) {
+    return `${baseUrl}/Items/${item.AlbumId}/Images/Primary?maxWidth=512&tag=${item.AlbumPrimaryImageTag}${key}`;
+  }
+  return "";
+}
+
+/** Direct (untranscoded) stream URL — the default playback path. */
+export function buildStreamUrl(baseUrl: string, apiKey: string, itemId: string): string {
+  const params = new URLSearchParams({ static: "true", api_key: apiKey });
+  return `${baseUrl}/Audio/${itemId}/stream?${params.toString()}`;
+}
+
+/** Server-side transcode URL for the 320/192/128 kbps tiers. */
+export function buildUniversalUrl(
+  baseUrl: string,
+  o: { apiKey: string; userId: string; deviceId: string; itemId: string; kbps: number },
+): string {
+  const params = new URLSearchParams({
+    userId: o.userId,
+    deviceId: o.deviceId,
+    api_key: o.apiKey,
+    maxStreamingBitrate: String(o.kbps * 1000),
+    container: "mp3,aac,m4a|aac,flac,webma,webm,wav,ogg",
+    transcodingContainer: "mp3",
+    transcodingProtocol: "http",
+  });
+  return `${baseUrl}/Audio/${o.itemId}/universal?${params.toString()}`;
+}
+
+export function mapJellyfinSong(item: JellyfinItem, coverUrl: string): Song {
+  return {
+    id: String(item.Id),
+    name: item.Name ?? "",
+    artist: (item.Artists?.length ? item.Artists : [item.AlbumArtist ?? ""])
+      .filter(Boolean)
+      .join(" / "),
+    album: item.Album ?? "",
+    duration: Math.round(ticksToSeconds(item.RunTimeTicks)),
+    coverUrl,
+    platform: "jellyfin",
+  };
+}
+
+export function mapJellyfinAlbum(item: JellyfinItem, coverUrl: string): Album {
+  return {
+    id: String(item.Id),
+    name: item.Name ?? "",
+    artist: item.AlbumArtist ?? (item.Artists ?? []).join(" / "),
+    coverUrl,
+    songCount: item.ChildCount ?? item.SongCount ?? 0,
+    platform: "jellyfin",
+  };
+}
+
+export function mapJellyfinPlaylist(item: JellyfinItem, coverUrl: string): Playlist {
+  return {
+    id: String(item.Id),
+    name: item.Name ?? "",
+    coverUrl,
+    songCount: item.ChildCount ?? item.SongCount ?? 0,
+    platform: "jellyfin",
+  };
+}
+
+/**
+ * Map `GET /Audio/{id}/Lyrics` → the bot's synced-lyric format. `Start` is in
+ * ticks; entries without Start (plain-text lyrics) collapse to time 0 so the
+ * lyric view still renders them, just without sync. Translation stays empty —
+ * Jellyfin has no translated-lyrics concept.
+ */
+export function mapJellyfinLyrics(payload: unknown): LyricLine[] {
+  const lyrics = (payload as { Lyrics?: { Text?: string; Start?: number }[] })?.Lyrics;
+  if (!Array.isArray(lyrics)) return [];
+  return lyrics
+    .filter((l) => typeof l?.Text === "string" && l.Text.trim() !== "")
+    .map((l) => ({ time: ticksToSeconds(l.Start), text: l.Text!.trim() }))
+    .sort((a, b) => a.time - b.time);
+}
+
+/** Operator-friendly connection/auth error description (test-connection UI + logs). */
+export function describeJellyfinError(err: unknown): string {
+  const e = err as AxiosError;
+  if (e?.response) {
+    const s = e.response.status;
+    if (s === 401) return "认证失败：用户名/密码或 API Key 不正确 (401 Unauthorized)";
+    if (s === 403) return "该账号没有访问权限 (403 Forbidden)";
+    if (s === 404) return "接口不存在——请确认地址指向 Jellyfin 根路径 (404 Not Found)";
+    return `Jellyfin 返回 HTTP ${s}`;
+  }
+  const code = (e as { code?: string })?.code;
+  if (code === "ECONNREFUSED") return "无法连接 Jellyfin 服务器 (connection refused)";
+  if (code === "ENOTFOUND" || code === "EAI_AGAIN") return "无法解析服务器地址 (DNS lookup failed)";
+  if (code === "ETIMEDOUT" || code === "ECONNABORTED") return "连接 Jellyfin 超时 (timeout)";
+  return (err as Error)?.message ?? String(err);
+}
+
+/**
+ * Per-bot playback reporting handle. One playback session (PlaySessionId) per
+ * track start; the previous session is closed with its last known position so
+ * Jellyfin's played/PlayCount bookkeeping sees natural track ends as ~complete
+ * plays and mid-track skips as partial ones. Every call is fire-and-forget —
+ * reporting must never affect playback.
+ */
+export interface JellyfinPlaybackReporter {
+  onTrackStart(itemId: string): void;
+  onTick(itemId: string, positionSec: number, paused: boolean): void;
+  onStop(): void;
+}
+
+interface PersistedAuth {
+  accessToken?: string;
+  userId?: string;
+  deviceId?: string;
+}
+
+function emptyConfig(): JellyfinConfig {
+  return { serverUrl: "", authMode: "userpass", username: "", password: "", apiKey: "", userId: "" };
+}
+
+export class JellyfinProvider implements MusicProvider {
+  readonly platform = "jellyfin" as const;
+  private api: AxiosInstance;
+  private cfg: JellyfinConfig = emptyConfig();
+  private token = "";
+  private userId = "";
+  private deviceId = "";
+  private quality: string = "direct";
+  private loginPromise: Promise<void> | null = null;
+  private persistFn: ((serialized: string) => void) | null = null;
+  private logger: Logger | null = null;
+
+  constructor(logger?: Logger) {
+    this.api = axios.create({ timeout: 10000 });
+    this.logger = logger ?? null;
+  }
+
+  /**
+   * Apply (or re-apply, on settings save) the admin-configured connection.
+   * Changing any credential-relevant field drops the cached token so the next
+   * request re-authenticates; the stable deviceId survives reconfiguration.
+   */
+  configure(cfg: JellyfinConfig): void {
+    const prev = this.cfg;
+    this.cfg = { ...cfg, serverUrl: (cfg.serverUrl ?? "").trim().replace(/\/+$/, "") };
+    const credsChanged =
+      prev.serverUrl !== this.cfg.serverUrl ||
+      prev.authMode !== this.cfg.authMode ||
+      prev.username !== this.cfg.username ||
+      prev.password !== this.cfg.password ||
+      prev.apiKey !== this.cfg.apiKey ||
+      prev.userId !== this.cfg.userId;
+    if (credsChanged) {
+      this.token = "";
+      this.userId = "";
+    }
+  }
+
+  isConfigured(): boolean {
+    return this.cfg.serverUrl.length > 0;
+  }
+
+  /** Wire the on-disk persistence used after a successful login (cookie store). */
+  setPersist(fn: (serialized: string) => void): void {
+    this.persistFn = fn;
+  }
+
+  setQuality(quality: string): void {
+    // Ignore foreign values: the legacy platform-less POST /api/music/quality
+    // broadcasts NetEase levels to every provider, which must not clobber the
+    // jellyfin default ("direct").
+    if (JELLYFIN_QUALITY_LEVELS.some((l) => l.value === quality)) {
+      this.quality = quality;
+    }
+  }
+
+  getQuality(): string {
+    return this.quality;
+  }
+
+  // --- Auth ---
+
+  private authHeader(): string {
+    return (
+      `MediaBrowser Client="${CLIENT_NAME}", Device="${CLIENT_NAME}", ` +
+      `DeviceId="${this.deviceId}", Version="${PKG_VERSION}"`
+    );
+  }
+
+  private ensureDeviceId(): void {
+    if (!this.deviceId) {
+      this.deviceId = crypto.randomUUID();
+      this.persistState();
+    }
+  }
+
+  private persistState(): void {
+    try {
+      this.persistFn?.(this.getCookie());
+    } catch (err) {
+      this.logger?.warn({ err }, "Failed to persist Jellyfin auth state");
+    }
+  }
+
+  private async login(): Promise<void> {
+    this.ensureDeviceId();
+    const res = await this.api.post(
+      `${this.cfg.serverUrl}/Users/AuthenticateByName`,
+      { Username: this.cfg.username, Pw: this.cfg.password },
+      { headers: { Authorization: this.authHeader() } },
+    );
+    const token = res.data?.AccessToken as string | undefined;
+    const userId = res.data?.User?.Id as string | undefined;
+    if (!token || !userId) {
+      throw new Error("Jellyfin 登录响应缺少 AccessToken/User.Id");
+    }
+    this.token = token;
+    this.userId = userId;
+    this.persistState();
+    this.logger?.info({ userId }, "Jellyfin authenticated");
+  }
+
+  private async ensureAuth(): Promise<void> {
+    if (!this.cfg.serverUrl) {
+      throw new Error("Jellyfin 未配置服务器地址 (server URL not configured)");
+    }
+    if (this.cfg.authMode === "apikey") {
+      if (!this.cfg.apiKey || !this.cfg.userId) {
+        throw new Error("Jellyfin API Key 模式需要 apiKey 和 userId");
+      }
+      this.token = this.cfg.apiKey;
+      this.userId = this.cfg.userId;
+      this.ensureDeviceId();
+      return;
+    }
+    if (this.token && this.userId) return;
+    if (!this.cfg.username) {
+      throw new Error("Jellyfin 未配置用户名/密码 (username not configured)");
+    }
+    if (!this.loginPromise) {
+      this.loginPromise = this.login().finally(() => {
+        this.loginPromise = null;
+      });
+    }
+    return this.loginPromise;
+  }
+
+  /** Authenticated request with a single re-auth retry on 401 (userpass mode). */
+  private async request<T = unknown>(
+    method: "get" | "post",
+    path: string,
+    opts: { params?: Record<string, unknown>; data?: unknown; retried?: boolean } = {},
+  ): Promise<T> {
+    await this.ensureAuth();
+    // Callers snapshot `userId: this.userId` while building params, which is
+    // still empty before the first login. ensureAuth() has populated it by
+    // now, so backfill the stale-empty snapshot instead of sending userId="".
+    const params = opts.params ? { ...opts.params } : undefined;
+    if (params && "userId" in params && !params.userId) params.userId = this.userId;
+    try {
+      const res = await this.api.request<T>({
+        method,
+        url: this.cfg.serverUrl + path,
+        params,
+        data: opts.data,
+        headers: { "X-Emby-Token": this.token },
+      });
+      return res.data;
+    } catch (err) {
+      const status = (err as AxiosError).response?.status;
+      if (status === 401 && this.cfg.authMode === "userpass" && !opts.retried) {
+        this.token = "";
+        this.userId = "";
+        return this.request(method, path, { ...opts, retried: true });
+      }
+      throw err;
+    }
+  }
+
+  // --- MusicProvider ---
+
+  private coverFor(item: JellyfinItem): string {
+    return buildCoverUrl(this.cfg.serverUrl, this.token, item);
+  }
+
+  private mapSongs(items: JellyfinItem[] | undefined | null): Song[] {
+    return (items ?? []).map((i) => mapJellyfinSong(i, this.coverFor(i)));
+  }
+
+  async search(query: string, limit = 20, offset = 0): Promise<SearchResult> {
+    const common = {
+      searchTerm: query,
+      Recursive: true,
+      Limit: limit,
+      StartIndex: offset,
+      userId: this.userId,
+    };
+    const [songRes, albumRes, playlistRes] = await Promise.all([
+      this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+        params: { ...common, IncludeItemTypes: "Audio" },
+      }),
+      this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+        params: { ...common, IncludeItemTypes: "MusicAlbum", Fields: "ChildCount" },
+      }),
+      this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+        params: { ...common, IncludeItemTypes: "Playlist", Fields: "ChildCount" },
+      }),
+    ]);
+    return {
+      songs: this.mapSongs(songRes?.Items),
+      albums: (albumRes?.Items ?? []).map((i) => mapJellyfinAlbum(i, this.coverFor(i))),
+      playlists: (playlistRes?.Items ?? []).map((i) => mapJellyfinPlaylist(i, this.coverFor(i))),
+    };
+  }
+
+  async getSongUrl(songId: string, quality?: string): Promise<SongUrlResult | null> {
+    await this.ensureAuth();
+    const level = quality ?? this.quality;
+    const tier = JELLYFIN_QUALITY_LEVELS.find((l) => l.value === level);
+    if (!tier || tier.value === "direct") {
+      return { url: buildStreamUrl(this.cfg.serverUrl, this.token, songId) };
+    }
+    return {
+      url: buildUniversalUrl(this.cfg.serverUrl, {
+        apiKey: this.token,
+        userId: this.userId,
+        deviceId: this.deviceId,
+        itemId: songId,
+        kbps: tier.bitrate,
+      }),
+    };
+  }
+
+  async getSongDetail(songId: string): Promise<Song | null> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: { ids: songId, userId: this.userId },
+    });
+    const item = res?.Items?.[0];
+    return item ? mapJellyfinSong(item, this.coverFor(item)) : null;
+  }
+
+  async getPlaylistSongs(playlistId: string): Promise<Song[]> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>(
+      "get",
+      `/Playlists/${playlistId}/Items`,
+      { params: { userId: this.userId } },
+    );
+    return this.mapSongs(res?.Items);
+  }
+
+  async getAlbumSongs(albumId: string): Promise<Song[]> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        parentId: albumId,
+        sortBy: "ParentIndexNumber,IndexNumber",
+        userId: this.userId,
+      },
+    });
+    return this.mapSongs(res?.Items);
+  }
+
+  async getRecommendPlaylists(): Promise<Playlist[]> {
+    return this.getUserPlaylists();
+  }
+
+  async getUserPlaylists(): Promise<Playlist[]> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        IncludeItemTypes: "Playlist",
+        Recursive: true,
+        Fields: "ChildCount",
+        SortBy: "SortName",
+        userId: this.userId,
+      },
+    });
+    return (res?.Items ?? []).map((i) => mapJellyfinPlaylist(i, this.coverFor(i)));
+  }
+
+  async getPlaylistDetail(playlistId: string): Promise<PlaylistDetail | null> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: { ids: playlistId, Fields: "ChildCount,Overview", userId: this.userId },
+    });
+    const item = res?.Items?.[0];
+    if (!item) return null;
+    return {
+      id: String(item.Id),
+      name: item.Name ?? "",
+      description: item.Overview ?? "",
+      coverUrl: this.coverFor(item),
+      songCount: item.ChildCount ?? 0,
+    };
+  }
+
+  async getLyrics(songId: string): Promise<LyricLine[]> {
+    try {
+      const res = await this.request<unknown>("get", `/Audio/${songId}/Lyrics`);
+      return mapJellyfinLyrics(res);
+    } catch (err) {
+      // 404 = the track simply has no lyrics — not an error.
+      if ((err as AxiosError).response?.status === 404) return [];
+      throw err;
+    }
+  }
+
+  // No QR-code login concept — connection is global and admin-configured.
+  async getQrCode(): Promise<QrCodeResult> {
+    return { qrUrl: "", key: "" };
+  }
+
+  async checkQrCodeStatus(): Promise<"waiting" | "scanned" | "confirmed" | "expired"> {
+    return "expired";
+  }
+
+  setCookie(cookie: string): void {
+    try {
+      const parsed = JSON.parse(cookie) as PersistedAuth;
+      if (parsed && typeof parsed === "object") {
+        if (typeof parsed.accessToken === "string") this.token = parsed.accessToken;
+        if (typeof parsed.userId === "string") this.userId = parsed.userId;
+        if (typeof parsed.deviceId === "string") this.deviceId = parsed.deviceId;
+      }
+    } catch {
+      // Not the JSON blob we persist — ignore rather than corrupt auth state.
+    }
+  }
+
+  getCookie(): string {
+    return JSON.stringify({
+      accessToken: this.token,
+      userId: this.userId,
+      deviceId: this.deviceId,
+    });
+  }
+
+  async getAuthStatus(): Promise<AuthStatus> {
+    if (!this.cfg.serverUrl) return { loggedIn: false };
+    try {
+      const info = await this.request<{ ServerName?: string }>("get", "/System/Info");
+      const who = this.cfg.authMode === "apikey" ? "API Key" : this.cfg.username;
+      return { loggedIn: true, nickname: `${who}@${info?.ServerName ?? "Jellyfin"}` };
+    } catch (err) {
+      this.logger?.debug({ err: describeJellyfinError(err) }, "Jellyfin auth status check failed");
+      return { loggedIn: false };
+    }
+  }
+
+  /**
+   * Authenticated round-trip to /System/Info for the Settings "test connection"
+   * button. `candidate` (when given) tests form values in a throwaway instance
+   * so a failed test never disturbs the live token state.
+   */
+  async testConnection(
+    candidate?: JellyfinConfig,
+  ): Promise<{ ok: boolean; serverName?: string; version?: string; error?: string }> {
+    const probe = candidate ? new JellyfinProvider() : this;
+    if (candidate) probe.configure(candidate);
+    try {
+      const info = await probe.request<{ ServerName?: string; Version?: string }>(
+        "get",
+        "/System/Info",
+      );
+      return { ok: true, serverName: info?.ServerName, version: info?.Version };
+    } catch (err) {
+      return { ok: false, error: describeJellyfinError(err) };
+    }
+  }
+
+  /**
+   * Personal FM = Instant Mix seeded from a random favorite, falling back to a
+   * random recently-played track, then a random library track. A final safety
+   * net returns 50 random tracks when Instant Mix itself yields nothing.
+   */
+  async getPersonalFm(): Promise<Song[]> {
+    const seed = await this.pickFmSeed();
+    if (seed) {
+      const mix = await this.request<{ Items?: JellyfinItem[] }>(
+        "get",
+        `/Items/${seed}/InstantMix`,
+        { params: { userId: this.userId, limit: 50 } },
+      );
+      const songs = this.mapSongs(mix?.Items);
+      if (songs.length > 0) return songs;
+    }
+    const random = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        IncludeItemTypes: "Audio",
+        Recursive: true,
+        SortBy: "Random",
+        Limit: 50,
+        userId: this.userId,
+      },
+    });
+    return this.mapSongs(random?.Items);
+  }
+
+  private async pickFmSeed(): Promise<string | null> {
+    const favorite = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        Filters: "IsFavorite",
+        IncludeItemTypes: "Audio",
+        Recursive: true,
+        SortBy: "Random",
+        Limit: 1,
+        userId: this.userId,
+      },
+    });
+    if (favorite?.Items?.[0]?.Id) return favorite.Items[0].Id;
+
+    const played = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        Filters: "IsPlayed",
+        IncludeItemTypes: "Audio",
+        Recursive: true,
+        SortBy: "DatePlayed",
+        SortOrder: "Descending",
+        Limit: 20,
+        userId: this.userId,
+      },
+    });
+    const playedItems = played?.Items ?? [];
+    if (playedItems.length > 0) {
+      return playedItems[Math.floor(Math.random() * playedItems.length)].Id;
+    }
+
+    const random = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        IncludeItemTypes: "Audio",
+        Recursive: true,
+        SortBy: "Random",
+        Limit: 1,
+        userId: this.userId,
+      },
+    });
+    return random?.Items?.[0]?.Id ?? null;
+  }
+
+  // --- Home sections ---
+
+  async getLatestAlbums(limit = 12): Promise<Album[]> {
+    await this.ensureAuth();
+    const items = await this.request<JellyfinItem[]>(
+      "get",
+      `/Users/${this.userId}/Items/Latest`,
+      { params: { IncludeItemTypes: "MusicAlbum", Limit: limit, Fields: "ChildCount" } },
+    );
+    return (Array.isArray(items) ? items : []).map((i) =>
+      mapJellyfinAlbum(i, this.coverFor(i)),
+    );
+  }
+
+  async getMostPlayed(limit = 12): Promise<Song[]> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        SortBy: "PlayCount",
+        SortOrder: "Descending",
+        IncludeItemTypes: "Audio",
+        Recursive: true,
+        Filters: "IsPlayed",
+        Limit: limit,
+        userId: this.userId,
+      },
+    });
+    return this.mapSongs(res?.Items);
+  }
+
+  async getFavoriteSongs(limit = 100): Promise<Song[]> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        Filters: "IsFavorite",
+        IncludeItemTypes: "Audio",
+        Recursive: true,
+        SortBy: "SortName",
+        Limit: limit,
+        userId: this.userId,
+      },
+    });
+    return this.mapSongs(res?.Items);
+  }
+
+  async getGenres(limit = 30): Promise<{ id: string; name: string }[]> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>("get", "/MusicGenres", {
+      params: { userId: this.userId, Limit: limit, SortBy: "SortName" },
+    });
+    return (res?.Items ?? []).map((i) => ({ id: String(i.Id), name: i.Name ?? "" }));
+  }
+
+  async getGenreSongs(genreId: string, limit = 100): Promise<Song[]> {
+    const res = await this.request<{ Items?: JellyfinItem[] }>("get", "/Items", {
+      params: {
+        GenreIds: genreId,
+        IncludeItemTypes: "Audio",
+        Recursive: true,
+        SortBy: "AlbumArtist,Album,SortName",
+        Limit: limit,
+        userId: this.userId,
+      },
+    });
+    return this.mapSongs(res?.Items);
+  }
+
+  // --- Playback reporting (Sessions API) ---
+
+  private async report(path: string, body: Record<string, unknown>): Promise<void> {
+    try {
+      await this.request("post", path, { data: body });
+    } catch (err) {
+      // Reporting must never affect playback — log and swallow.
+      this.logger?.debug(
+        { err: describeJellyfinError(err), path },
+        "Jellyfin playback report failed",
+      );
+    }
+  }
+
+  createPlaybackReporter(): JellyfinPlaybackReporter {
+    // One session per track start; remember the last reported position so the
+    // implicit stop on track change carries a sane PositionTicks (a natural
+    // track end reports ~full duration → Jellyfin counts the play).
+    let current: { itemId: string; sessionId: string; lastPosSec: number } | null = null;
+    const report = this.report.bind(this);
+    return {
+      onTrackStart(itemId: string): void {
+        if (current) {
+          void report("/Sessions/Playing/Stopped", {
+            ItemId: current.itemId,
+            PlaySessionId: current.sessionId,
+            PositionTicks: Math.round(current.lastPosSec * TICKS_PER_SECOND),
+          });
+        }
+        current = { itemId, sessionId: crypto.randomUUID(), lastPosSec: 0 };
+        void report("/Sessions/Playing", {
+          ItemId: itemId,
+          PlaySessionId: current.sessionId,
+          PositionTicks: 0,
+          CanSeek: true,
+        });
+      },
+      onTick(itemId: string, positionSec: number, paused: boolean): void {
+        if (!current || current.itemId !== itemId) return;
+        current.lastPosSec = positionSec;
+        void report("/Sessions/Playing/Progress", {
+          ItemId: itemId,
+          PlaySessionId: current.sessionId,
+          PositionTicks: Math.round(positionSec * TICKS_PER_SECOND),
+          IsPaused: paused,
+        });
+      },
+      onStop(): void {
+        if (!current) return;
+        void report("/Sessions/Playing/Stopped", {
+          ItemId: current.itemId,
+          PlaySessionId: current.sessionId,
+          PositionTicks: Math.round(current.lastPosSec * TICKS_PER_SECOND),
+        });
+        current = null;
+      },
+    };
+  }
+}