feat(search): server-side offset pagination through providers + /search route (#115 backend)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/music/bilibili.test.ts

@@ -0,0 +1,39 @@
+import { describe, it, expect, vi } from "vitest";
+import { BiliBiliProvider } from "./bilibili.js";
+
+describe("BiliBiliProvider.search pagination", () => {
+  function mockProvider() {
+    const p = new BiliBiliProvider();
+    const get = vi.fn().mockResolvedValue({ data: { data: { result: [] } } });
+    // Short-circuit the buvid + wbi bootstrap so search only issues the
+    // /search/type request we want to inspect.
+    (p as any).buvidInitialized = true;
+    (p as any).wbiMixinKey = "0".repeat(32);
+    (p as any).wbiKeyFetchedAt = Date.now();
+    (p as any).api = { get };
+    return { p, get };
+  }
+
+  function searchParams(get: ReturnType<typeof vi.fn>) {
+    const call = get.mock.calls.find(
+      (c: any[]) => c[0] === "/x/web-interface/wbi/search/type"
+    );
+    expect(call, "expected a /search/type call").toBeTruthy();
+    // signWbi stringifies every value.
+    return call![1].params as Record<string, string>;
+  }
+
+  it("adds page (offset/limit+1) alongside page_size", async () => {
+    const { p, get } = mockProvider();
+    await p.search("hello", 20, 20); // page 2
+    const params = searchParams(get);
+    expect(params.page).toBe("2");
+    expect(params.page_size).toBe("20");
+  });
+
+  it("defaults offset to 0 → page 1 (backward compatible)", async () => {
+    const { p, get } = mockProvider();
+    await p.search("hello", 20);
+    expect(searchParams(get).page).toBe("1");
+  });
+});

src/music/bilibili.ts

@@ -147,12 +147,16 @@ export class BiliBiliProvider implements MusicProvider {
     return fixed;
   }
 
-  async search(query: string, limit = 20): Promise<SearchResult> {
+  async search(query: string, limit = 20, offset = 0): Promise<SearchResult> {
     await this.ensureBuvidCookie();
     await this.ensureWbiKeys();
+    // /search/type is page-based; the web pages in limit-aligned steps so
+    // offset is a multiple of page_size.
+    const page = Math.floor(offset / limit) + 1;
     const signed = this.signWbi({
       search_type: "video",
       keyword: query,
+      page,
       page_size: limit,
     });
     const res = await this.api.get("/x/web-interface/wbi/search/type", {

src/music/kugou.test.ts

@@ -1,5 +1,5 @@
-import { describe, it, expect } from "vitest";
-import { mapKugouSong, mapKugouSongs, mapKugouAlbums, mapKugouPlaylist, mapKugouPlaylists, krcToLrc } from "./kugou.js";
+import { describe, it, expect, vi } from "vitest";
+import { mapKugouSong, mapKugouSongs, mapKugouAlbums, mapKugouPlaylist, mapKugouPlaylists, krcToLrc, KugouProvider } from "./kugou.js";
 import { parseLyrics } from "./netease.js";
 
 describe("mapKugouSongs", () => {
@@ -193,3 +193,32 @@ describe("mapKugouPlaylists", () => {
     expect(mapKugouPlaylists(undefined)).toEqual([]);
   });
 });
+
+describe("KugouProvider.search pagination", () => {
+  function mockProvider() {
+    const p = new KugouProvider();
+    const get = vi.fn().mockResolvedValue({ data: { data: { info: [] } } });
+    (p as any).mobileHttp = { get };
+    return { p, get };
+  }
+
+  function searchParams(get: ReturnType<typeof vi.fn>) {
+    const call = get.mock.calls[0];
+    expect(call, "expected a mobile search call").toBeTruthy();
+    return call[1].params as Record<string, unknown>;
+  }
+
+  it("sets page to offset/limit+1 and keeps pagesize=limit", async () => {
+    const { p, get } = mockProvider();
+    await p.search("hello", 20, 20); // page 2
+    const params = searchParams(get);
+    expect(params.page).toBe(2);
+    expect(params.pagesize).toBe(20);
+  });
+
+  it("defaults offset to 0 → page 1 (backward compatible)", async () => {
+    const { p, get } = mockProvider();
+    await p.search("hello", 20);
+    expect(searchParams(get).page).toBe(1);
+  });
+});

src/music/kugou.ts

@@ -616,12 +616,15 @@ export class KugouProvider implements MusicProvider {
   }
 
   // --- Search (verified live via the unsigned mobile endpoint) ---------------
-  async search(query: string, limit = 20): Promise<SearchResult> {
+  async search(query: string, limit = 20, offset = 0): Promise<SearchResult> {
     const q = query.trim();
     if (!q) return { songs: [], playlists: [], albums: [] };
     try {
+      // Songs only. `page` is the 1-based cursor; the web pages in limit-aligned
+      // steps so offset is a multiple of pagesize.
+      const page = Math.floor(offset / limit) + 1;
       const res = await this.mobileHttp.get("http://mobilecdn.kugou.com/api/v3/search/song", {
-        params: { format: "json", keyword: q, page: 1, pagesize: limit, showtype: 1 },
+        params: { format: "json", keyword: q, page, pagesize: limit, showtype: 1 },
       });
       const info = res.data?.data?.info as KugouRawSong[] | undefined;
       return { songs: mapKugouSongs(info), playlists: [], albums: [] };

src/music/local.test.ts

@@ -205,6 +205,20 @@ describe("LocalMusicProvider quota", () => {
   });
 });
 
+describe("LocalMusicProvider search pagination", () => {
+  it("slices [offset, offset+limit) instead of the first page", async () => {
+    const recs = ["a", "b", "c", "d"].map((id) => makeRecord(id));
+    seed(recs); // newest-first order preserved: a, b, c, d
+    const p = new LocalMusicProvider(dir);
+
+    const page1 = await p.search("", 2); // offset defaults to 0
+    expect(page1.songs.map((s) => s.id)).toEqual(["a", "b"]);
+
+    const page2 = await p.search("", 2, 2);
+    expect(page2.songs.map((s) => s.id)).toEqual(["c", "d"]);
+  });
+});
+
 describe("LocalMusicProvider filename handling", () => {
   it("accepts a long filename without dropping its extension", async () => {
     const p = new LocalMusicProvider(dir);

src/music/local.ts

@@ -214,12 +214,12 @@ export class LocalMusicProvider implements MusicProvider {
     return song;
   }
 
-  async search(query: string, limit = 20): Promise<SearchResult> {
+  async search(query: string, limit = 20, offset = 0): Promise<SearchResult> {
     const q = query.trim().toLowerCase();
     const songs = this.records
       .filter((r) => existsSync(r.filePath))
       .filter((r) => !q || `${r.name} ${r.artist} ${r.album} ${r.originalName}`.toLowerCase().includes(q))
-      .slice(0, limit)
+      .slice(offset, offset + limit)
       .map((r) => this.toSong(r));
     return { songs, playlists: [], albums: [] };
   }

src/music/netease.test.ts

@@ -1,5 +1,5 @@
-import { describe, it, expect } from "vitest";
-import { parseLyrics, mapNeteaseAlbums, mapNeteaseSongs, parseNeteaseTrial } from "./netease.js";
+import { describe, it, expect, vi } from "vitest";
+import { parseLyrics, mapNeteaseAlbums, mapNeteaseSongs, parseNeteaseTrial, NeteaseProvider } from "./netease.js";
 
 describe("NetEase adapter", () => {
   it("parses LRC format lyrics", () => {
@@ -93,3 +93,49 @@ describe("NetEase adapter", () => {
     expect(parseNeteaseTrial({ freeTrialInfo: { start: 0, end: 0 } })).toBeUndefined();
   });
 });
+
+describe("NeteaseProvider.search pagination", () => {
+  function mockProvider() {
+    const p = new NeteaseProvider("http://x");
+    const get = vi.fn().mockResolvedValue({
+      data: { result: { songs: [], playlists: [], albums: [] } },
+    });
+    (p as any).api = { get };
+    return { p, get };
+  }
+
+  /** Find the /cloudsearch call whose params.type matches. */
+  function callByType(get: ReturnType<typeof vi.fn>, type: number) {
+    const call = get.mock.calls.find((c: any[]) => c[1]?.params?.type === type);
+    expect(call, `expected a /cloudsearch call with type=${type}`).toBeTruthy();
+    return call![1].params as Record<string, unknown>;
+  }
+
+  it("forwards offset for songs and uses real limit+offset for playlists/albums", async () => {
+    const { p, get } = mockProvider();
+    await p.search("hello", 20, 20);
+
+    // songs (type 1): offset forwarded, limit unchanged
+    const songs = callByType(get, 1);
+    expect(songs.limit).toBe(20);
+    expect(songs.offset).toBe(20);
+
+    // playlists (type 1000): limit-driven (NOT hardcoded 10) + offset
+    const playlists = callByType(get, 1000);
+    expect(playlists.limit).toBe(20);
+    expect(playlists.offset).toBe(20);
+
+    // albums (type 10): limit-driven (NOT hardcoded 10) + offset
+    const albums = callByType(get, 10);
+    expect(albums.limit).toBe(20);
+    expect(albums.offset).toBe(20);
+  });
+
+  it("defaults offset to 0 (backward compatible)", async () => {
+    const { p, get } = mockProvider();
+    await p.search("hello", 20);
+    expect(callByType(get, 1).offset).toBe(0);
+    expect(callByType(get, 1000).offset).toBe(0);
+    expect(callByType(get, 10).offset).toBe(0);
+  });
+});

src/music/netease.ts

@@ -131,21 +131,25 @@ export class NeteaseProvider implements MusicProvider {
     return this.cookie ? { cookie: this.cookie } : {};
   }
 
-  async search(query: string, limit = 20): Promise<SearchResult> {
+  async search(query: string, limit = 20, offset = 0): Promise<SearchResult> {
+    // /cloudsearch supports offset for every type. Songs, playlists (type 1000)
+    // and albums (type 10) are all limit/offset-driven so the web can page past
+    // the first page (playlists/albums were previously hardcoded to limit: 10).
     const [songRes, playlistRes, albumRes] = await Promise.all([
       this.api.get("/cloudsearch", {
-        params: { keywords: query, type: 1, limit, ...this.cookieParams },
+        params: { keywords: query, type: 1, limit, offset, ...this.cookieParams },
       }),
       this.api.get("/cloudsearch", {
         params: {
           keywords: query,
           type: 1000,
-          limit: 10,
+          limit,
+          offset,
           ...this.cookieParams,
         },
       }),
       this.api.get("/cloudsearch", {
-        params: { keywords: query, type: 10, limit: 10, ...this.cookieParams },
+        params: { keywords: query, type: 10, limit, offset, ...this.cookieParams },
       }),
     ]);
 

src/music/provider.ts

@@ -74,7 +74,7 @@ export interface AuthStatus {
 export interface MusicProvider {
   readonly platform: "netease" | "qq" | "bilibili" | "youtube" | "local" | "kugou";
 
-  search(query: string, limit?: number): Promise<SearchResult>;
+  search(query: string, limit?: number, offset?: number): Promise<SearchResult>;
   getSongUrl(songId: string, quality?: string): Promise<SongUrlResult | null>;
   setQuality(quality: string): void;
   getQuality(): string;

src/music/qq.test.ts

@@ -1,5 +1,14 @@
-import { describe, it, expect } from "vitest";
-import { mapQqAlbums, mapQqSongs, parseQqTrial } from "./qq.js";
+import { describe, it, expect, vi, beforeEach } from "vitest";
+
+// All axios.create(...) instances in qq.ts (qqMusicuApi / qqSearchApi / qqFavApi
+// and the per-instance api) share this single mock so the search test can
+// inspect the outgoing params/body regardless of which client issued them.
+const { mockGet, mockPost } = vi.hoisted(() => ({ mockGet: vi.fn(), mockPost: vi.fn() }));
+vi.mock("axios", () => ({
+  default: { create: () => ({ get: mockGet, post: mockPost }) },
+}));
+
+import { mapQqAlbums, mapQqSongs, parseQqTrial, QQMusicProvider } from "./qq.js";
 
 describe("QQ adapter", () => {
   it("mapQqSongs maps QQMusicApi-style song entries", () => {
@@ -92,3 +101,74 @@ describe("QQ adapter", () => {
     expect(out[0].id).toBe("");
   });
 });
+
+describe("QQMusicProvider.search pagination", () => {
+  beforeEach(() => {
+    mockGet.mockReset();
+    mockPost.mockReset();
+  });
+
+  /** musicu.fcg returns one song → primary path succeeds. */
+  function musicuOk() {
+    mockGet.mockImplementation(async (url: string) => {
+      if (url === "/cgi-bin/musicu.fcg") {
+        return {
+          data: {
+            req_0: { data: { body: { song: { list: [{ mid: "m1", name: "S", singer: [], album: {}, interval: 100 }] } } } },
+            req_album: { data: { body: { album: { list: [] } } } },
+            req_playlist: { data: { body: { songlist: { list: [] } } } },
+          },
+        };
+      }
+      return { data: {} };
+    });
+  }
+
+  function musicuReqData() {
+    const call = mockGet.mock.calls.find((c: any[]) => c[0] === "/cgi-bin/musicu.fcg");
+    expect(call, "expected a musicu.fcg call").toBeTruthy();
+    return JSON.parse(call![1].params.data);
+  }
+
+  it("adds page_num (offset/limit+1) and limit-driven num_per_page for songs/albums/playlists", async () => {
+    musicuOk();
+    const p = new QQMusicProvider("http://x");
+    await p.search("hello", 20, 20); // page 2
+
+    const d = musicuReqData();
+    expect(d.req_0.param.page_num).toBe(2);
+    expect(d.req_0.param.num_per_page).toBe(20);
+    // Albums/playlists: num_per_page must be limit-driven (NOT hardcoded 10).
+    expect(d.req_album.param.page_num).toBe(2);
+    expect(d.req_album.param.num_per_page).toBe(20);
+    expect(d.req_playlist.param.page_num).toBe(2);
+    expect(d.req_playlist.param.num_per_page).toBe(20);
+  });
+
+  it("defaults offset to 0 → page_num 1 (backward compatible)", async () => {
+    musicuOk();
+    const p = new QQMusicProvider("http://x");
+    await p.search("hello", 20);
+    const d = musicuReqData();
+    expect(d.req_0.param.page_num).toBe(1);
+  });
+
+  it("fallback client_search_cp sets p to the page cursor", async () => {
+    // musicu returns no songs → primary returns null → fallback runs.
+    mockGet.mockImplementation(async (url: string) => {
+      if (url === "/cgi-bin/musicu.fcg") {
+        return { data: { req_0: { data: { body: { song: { list: [] } } } } } };
+      }
+      // client_search_cp
+      return { data: { data: { song: { list: [] }, album: { list: [] } } } };
+    });
+    const p = new QQMusicProvider("http://x");
+    await p.search("hello", 20, 20); // page 2
+
+    const songCall = mockGet.mock.calls.find(
+      (c: any[]) => c[0] === "/soso/fcgi-bin/client_search_cp" && c[1]?.params?.type === 0
+    );
+    expect(songCall, "expected a client_search_cp song call").toBeTruthy();
+    expect(songCall![1].params.p).toBe(2);
+  });
+});

src/music/qq.ts

@@ -149,16 +149,16 @@ export class QQMusicProvider implements MusicProvider {
     };
   }
 
-  async search(query: string, limit = 20): Promise<SearchResult> {
+  async search(query: string, limit = 20, offset = 0): Promise<SearchResult> {
     // Primary: u.y.qq.com/cgi-bin/musicu.fcg — supports songs + albums +
     // playlists. Fixed per https://github.com/ZHANGTIANYAO1/teamspeak-music-bot/issues/61
     // (removed searchid, num_per_page >= 10, corrected search_type values).
-    const primary = await this.searchViaMusicuFcg(query, limit);
+    const primary = await this.searchViaMusicuFcg(query, limit, offset);
     if (primary) return primary;
 
     // Fallback: c.y.qq.com/soso/fcgi-bin/client_search_cp (song + album,
     // no playlist support). Kept as redundancy.
-    return this.searchViaClientSearchCp(query, limit);
+    return this.searchViaClientSearchCp(query, limit, offset);
   }
 
   /** Primary search via u.y.qq.com/cgi-bin/musicu.fcg.
@@ -169,25 +169,31 @@ export class QQMusicProvider implements MusicProvider {
    *   3. `search_type: 2` for albums, `3` for playlists (8 was "user"). */
   private async searchViaMusicuFcg(
     query: string,
-    limit: number
+    limit: number,
+    offset = 0
   ): Promise<SearchResult | null> {
     try {
+      // num_per_page must stay >= 10 (lower values return empty). It is now
+      // limit-driven for ALL three lists (albums/playlists were hardcoded to
+      // 10). page_num is the offset cursor; the web always requests in
+      // limit-aligned pages so offset is a multiple of limit.
       const numPerPage = Math.max(10, Math.min(limit, 50));
+      const pageNum = Math.floor(offset / limit) + 1;
       const reqData = JSON.stringify({
         req_0: {
           module: "music.search.SearchCgiService",
           method: "DoSearchForQQMusicDesktop",
-          param: { query, num_per_page: numPerPage, search_type: 0 },
+          param: { query, num_per_page: numPerPage, page_num: pageNum, search_type: 0 },
         },
         req_album: {
           module: "music.search.SearchCgiService",
           method: "DoSearchForQQMusicDesktop",
-          param: { query, num_per_page: 10, search_type: 2 },
+          param: { query, num_per_page: numPerPage, page_num: pageNum, search_type: 2 },
         },
         req_playlist: {
           module: "music.search.SearchCgiService",
           method: "DoSearchForQQMusicDesktop",
-          param: { query, num_per_page: 10, search_type: 3 },
+          param: { query, num_per_page: numPerPage, page_num: pageNum, search_type: 3 },
         },
       });
       const res = await qqMusicuApi.get("/cgi-bin/musicu.fcg", {
@@ -221,12 +227,16 @@ export class QQMusicProvider implements MusicProvider {
   /** Fallback search via c.y.qq.com/soso/fcgi-bin/client_search_cp */
   private async searchViaClientSearchCp(
     query: string,
-    limit: number
+    limit: number,
+    offset = 0
   ): Promise<SearchResult> {
+    // `p` is the 1-based page cursor. The web pages in limit-aligned steps so
+    // offset is a multiple of limit.
+    const page = Math.floor(offset / limit) + 1;
     const songParams = {
       w: query,
       format: "json",
-      p: 1,
+      p: page,
       n: Math.min(limit, 50),
       type: 0,
       cr: 1,
@@ -234,7 +244,7 @@ export class QQMusicProvider implements MusicProvider {
     const albumParams = {
       w: query,
       format: "json",
-      p: 1,
+      p: page,
       n: 5,
       t: 8,
       cr: 1,

src/music/youtube.ts

@@ -115,20 +115,26 @@ export class YouTubeProvider implements MusicProvider {
   readonly platform = "youtube" as const;
   private quality = "bestaudio";
 
-  async search(query: string, limit = 5): Promise<SearchResult> {
+  async search(query: string, limit = 5, offset = 0): Promise<SearchResult> {
     try {
+      // yt-dlp's `ytsearchN` has no offset cursor — it always returns the first
+      // N results. Best-effort paginate by fetching offset+limit and slicing
+      // locally. (offset 0 → identical to before.)
+      const total = offset + limit;
       const raw = await runYtDlp([
-        `ytsearch${limit}:${query}`,
+        `ytsearch${total}:${query}`,
         "--dump-json",
         "--flat-playlist",
         "--no-warnings",
         "--quiet",
       ]);
       const lines = raw.trim().split("\n").filter(Boolean);
-      const songs: Song[] = lines.map((line) => {
-        const entry = JSON.parse(line) as YtDlpEntry;
-        return entryToSong(entry);
-      });
+      const songs: Song[] = lines
+        .slice(offset, offset + limit)
+        .map((line) => {
+          const entry = JSON.parse(line) as YtDlpEntry;
+          return entryToSong(entry);
+        });
       return { songs, playlists: [], albums: [] };
     } catch {
       return { songs: [], playlists: [], albums: [] };

src/web/api/music.test.ts

@@ -0,0 +1,49 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import express from "express";
+import request from "supertest";
+import pino from "pino";
+import type { MusicProvider, SearchResult } from "../../music/provider.js";
+import { createMusicRouter } from "./music.js";
+
+function fakeProvider(platform: MusicProvider["platform"]): MusicProvider {
+  const empty: SearchResult = { songs: [], albums: [], playlists: [] };
+  return {
+    platform,
+    search: vi.fn().mockResolvedValue(empty),
+  } as unknown as MusicProvider;
+}
+
+describe("music router GET /search offset pagination", () => {
+  let app: express.Express;
+  let netease: MusicProvider;
+
+  beforeEach(() => {
+    netease = fakeProvider("netease");
+    const router = createMusicRouter(
+      netease,
+      fakeProvider("qq"),
+      fakeProvider("bilibili"),
+      pino({ level: "silent" })
+    );
+    app = express();
+    app.use("/api/music", router);
+  });
+
+  it("parses offset and passes it as the 3rd arg to provider.search", async () => {
+    const res = await request(app).get("/api/music/search?q=hello&limit=20&offset=20");
+    expect(res.status).toBe(200);
+    expect(netease.search).toHaveBeenCalledWith("hello", 20, 20);
+  });
+
+  it("defaults a missing offset to 0", async () => {
+    const res = await request(app).get("/api/music/search?q=hello&limit=20");
+    expect(res.status).toBe(200);
+    expect(netease.search).toHaveBeenCalledWith("hello", 20, 0);
+  });
+
+  it("clamps a negative offset to 0", async () => {
+    const res = await request(app).get("/api/music/search?q=hello&limit=20&offset=-5");
+    expect(res.status).toBe(200);
+    expect(netease.search).toHaveBeenCalledWith("hello", 20, 0);
+  });
+});

src/web/api/music.ts

@@ -84,7 +84,7 @@ export function createMusicRouter(
 
   router.get("/search", async (req, res) => {
     try {
-      const { q, platform, limit } = req.query;
+      const { q, platform, limit, offset } = req.query;
       if (!q) {
         res.status(400).json({ error: "q (query) is required" });
         return;
@@ -94,9 +94,13 @@ export function createMusicRouter(
         return;
       }
       const provider = getProvider(platform as string);
+      // Server-side pagination: offset lets the web load past the first page.
+      // Clamp to >= 0 so a bad/negative value falls back to the first page.
+      const parsedOffset = Math.max(0, parseInt(offset as string) || 0);
       const result = await provider.search(
         q as string,
-        parseInt(limit as string) || 20
+        parseInt(limit as string) || 20,
+        parsedOffset
       );
       res.json(result);
     } catch (err) {