feat: add configurable default music source (#126)

Make the default playback source a user-configurable setting so servers
that mostly play e.g. Bilibili no longer need to type `-b` on every
`!play`. Previously defaultPlatform() always picked the first enabled
provider by a fixed priority order, with no way to override it.

- config: add optional `defaultPlatform: GateableProvider | null`.
  loadConfig sanitizes it — kept only when it names a known provider that
  is also currently enabled, else null. defaultPlatform() returns the
  preference when enabled, otherwise falls back to the fixed priority order.
- POST /api/bot/settings accepts `defaultPlatform` (validated against the
  possibly-updated enabledProviders; null/"" clears it), and reconciles a
  stored default that a new enabledProviders list no longer allows. GET and
  POST responses expose the field.
- WebUI: new "默认音源" section with a source picker; saving refreshes the
  store's default source so it takes effect immediately without a restart.
- Tests: extend config defaultPlatform priority tests and add coverage for
  the settings endpoint and /providers routing.
- README: document `defaultPlatform` in the enabledProviders section.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/data/config.test.ts

@@ -82,6 +82,61 @@ describe("config", () => {
     expect(defaultPlatform(config)).toBe("netease");
   });
 
+  // --- #126: an explicit operator default source ---
+
+  it("defaultPlatform is null by default (follow the priority order)", () => {
+    expect(getDefaultConfig().defaultPlatform).toBeNull();
+  });
+
+  it("defaultPlatform() honors an explicit, enabled preference over the priority order", () => {
+    const config = getDefaultConfig();
+    // Priority would pick netease; a Bilibili-loving server sets B站 instead (#126).
+    config.defaultPlatform = "bilibili";
+    expect(defaultPlatform(config)).toBe("bilibili");
+  });
+
+  it("defaultPlatform() ignores a preference whose source is not enabled", () => {
+    const config = getDefaultConfig();
+    config.defaultPlatform = "jellyfin"; // opt-in, not enabled in the default config
+    // Falls back to the fixed priority order (netease)…
+    expect(defaultPlatform(config)).toBe("netease");
+    // …until the preferred source is actually enabled.
+    config.enabledProviders = [...config.enabledProviders, "jellyfin"];
+    expect(defaultPlatform(config)).toBe("jellyfin");
+  });
+
+  it("loadConfig keeps a valid, enabled defaultPlatform", () => {
+    const dir = makeTmpDir();
+    const path = join(dir, "config.json");
+    writeFileSync(path, JSON.stringify({ defaultPlatform: "bilibili" }));
+    const config = loadConfig(path);
+    expect(config.defaultPlatform).toBe("bilibili");
+    expect(defaultPlatform(config)).toBe("bilibili");
+  });
+
+  it("loadConfig nulls a defaultPlatform that is unknown, disabled, or the wrong type", () => {
+    const dir = makeTmpDir();
+    // Unknown provider name.
+    const p1 = join(dir, "c1.json");
+    writeFileSync(p1, JSON.stringify({ defaultPlatform: "bogus" }));
+    expect(loadConfig(p1).defaultPlatform).toBeNull();
+    // Known provider, but not in enabledProviders.
+    const p2 = join(dir, "c2.json");
+    writeFileSync(p2, JSON.stringify({ enabledProviders: ["netease"], defaultPlatform: "bilibili" }));
+    expect(loadConfig(p2).defaultPlatform).toBeNull();
+    // Wrong type.
+    const p3 = join(dir, "c3.json");
+    writeFileSync(p3, JSON.stringify({ defaultPlatform: 42 }));
+    expect(loadConfig(p3).defaultPlatform).toBeNull();
+  });
+
+  it("round-trips defaultPlatform through save/load", () => {
+    const dir = makeTmpDir();
+    const path = join(dir, "config.json");
+    saveConfig(path, { ...getDefaultConfig(), defaultPlatform: "qq" });
+    expect(loadConfig(path).defaultPlatform).toBe("qq");
+  });
+
   it("respects an explicit jellyfin-only enabledProviders from disk", () => {
     const dir = makeTmpDir();
     const path = join(dir, "config.json");

src/data/config.ts

@@ -61,15 +61,24 @@ export function isProviderEnabled(config: BotConfig, platform: string): boolean
 }
 
 /**
- * The default platform for !play/!add/!playlist/!album and all REST/WebUI calls:
- * the first enabled provider in a fixed priority order (netease with the default
- * config; jellyfin ranks after the online music platforms because it is an
- * opt-in source, but ahead of the video sites for users who run it as their
- * only music library). Falls back to "netease" when nothing is enabled so
- * callers always get a provider — the enabled-gate then produces the friendly
- * error.
+ * The default platform for !play/!add/!playlist/!album and all REST/WebUI calls.
+ *
+ * An explicit user preference (`config.defaultPlatform`) wins whenever it points
+ * at a source that is currently enabled — this lets e.g. a Bilibili-loving server
+ * set B站 as the default so `!play <歌名>` needs no `-b` flag (issue #126). The
+ * enabled-guard here matters at runtime too: if the operator later disables the
+ * preferred source, we must fall through instead of returning a dead default.
+ *
+ * With no (usable) preference we fall back to the first enabled provider in a
+ * fixed priority order (netease with the default config; jellyfin ranks after
+ * the online music platforms because it is an opt-in source, but ahead of the
+ * video sites for users who run it as their only music library). Falls back to
+ * "netease" when nothing is enabled so callers always get a provider — the
+ * enabled-gate then produces the friendly error.
  */
 export function defaultPlatform(config: BotConfig): GateableProvider {
+  const pref = config.defaultPlatform;
+  if (pref && config.enabledProviders.includes(pref)) return pref;
   for (const p of ["netease", "qq", "kugou", "jellyfin", "bilibili", "youtube"] as const) {
     if (config.enabledProviders.includes(p)) return p;
   }
@@ -110,6 +119,14 @@ export interface BotConfig {
    * API servers must not start (or bind ports 3001/3200) unless enabled.
    */
   enabledProviders: GateableProvider[];
+  /**
+   * Optional operator-chosen default source for commands/REST/WebUI calls that
+   * omit a platform (issue #126). When set to an enabled gateable provider it
+   * overrides the fixed priority order in defaultPlatform(); `null` (the default)
+   * keeps that priority order. loadConfig cleans stale/unknown/disabled values
+   * back to null.
+   */
+  defaultPlatform: GateableProvider | null;
 }
 
 export function getDefaultConfig(): BotConfig {
@@ -163,6 +180,7 @@ export function getDefaultConfig(): BotConfig {
       userId: "",
     },
     enabledProviders: ["netease", "qq", "bilibili", "youtube", "kugou"],
+    defaultPlatform: null,
   };
 }
 
@@ -317,6 +335,18 @@ export function loadConfig(path: string): BotConfig {
         )
       : defaults.enabledProviders;
 
+    // defaultPlatform → an explicit operator default (issue #126). Keep it only
+    // when it names a KNOWN gateable provider that is ALSO currently enabled;
+    // anything else (unknown value, disabled source, wrong type, missing) becomes
+    // null so defaultPlatform() falls back to the fixed priority order.
+    const rawDefault = partial.defaultPlatform;
+    const defaultPlatformPref: GateableProvider | null =
+      typeof rawDefault === "string" &&
+      (GATEABLE_PROVIDERS as readonly string[]).includes(rawDefault) &&
+      enabledProviders.includes(rawDefault as GateableProvider)
+        ? (rawDefault as GateableProvider)
+        : null;
+
     return {
       ...defaults,
       ...partial,
@@ -325,6 +355,7 @@ export function loadConfig(path: string): BotConfig {
       spotify,
       jellyfin,
       enabledProviders,
+      defaultPlatform: defaultPlatformPref,
     };
   }
 }

src/web/api/bot.test.ts

@@ -647,4 +647,54 @@ describe("bot router /settings jellyfin block + enabledProviders", () => {
     // No jellyfin block in the request → no reconfigure call.
     expect(configureCalls).toHaveLength(0);
   });
+
+  // --- #126: operator-chosen default source ---
+
+  it("GET /settings exposes defaultPlatform (null by default)", async () => {
+    const res = await request(mountBot()).get("/api/bot/settings");
+    expect(res.status).toBe(200);
+    expect(res.body.defaultPlatform).toBeNull();
+  });
+
+  it("POST /settings sets an enabled defaultPlatform and persists it", async () => {
+    const res = await request(mountBot()).post("/api/bot/settings").send({
+      defaultPlatform: "bilibili",
+    });
+    expect(res.status).toBe(200);
+    expect(res.body.defaultPlatform).toBe("bilibili");
+    expect(config.defaultPlatform).toBe("bilibili");
+    const onDisk = JSON.parse(readFileSync(configPath, "utf-8"));
+    expect(onDisk.defaultPlatform).toBe("bilibili");
+  });
+
+  it("POST /settings ignores an unknown or disabled defaultPlatform", async () => {
+    const app = mountBot();
+    // jellyfin is opt-in and not enabled in the default config → rejected.
+    await request(app).post("/api/bot/settings").send({ defaultPlatform: "jellyfin" });
+    expect(config.defaultPlatform).toBeNull();
+    // Unknown value → rejected.
+    await request(app).post("/api/bot/settings").send({ defaultPlatform: "bogus" });
+    expect(config.defaultPlatform).toBeNull();
+  });
+
+  it("POST /settings clears defaultPlatform with null", async () => {
+    const app = mountBot();
+    await request(app).post("/api/bot/settings").send({ defaultPlatform: "qq" });
+    expect(config.defaultPlatform).toBe("qq");
+    const res = await request(app).post("/api/bot/settings").send({ defaultPlatform: null });
+    expect(res.body.defaultPlatform).toBeNull();
+    expect(config.defaultPlatform).toBeNull();
+  });
+
+  it("POST /settings drops a default whose source gets disabled in the same request", async () => {
+    const app = mountBot();
+    await request(app).post("/api/bot/settings").send({ defaultPlatform: "qq" });
+    expect(config.defaultPlatform).toBe("qq");
+    // Disabling qq via enabledProviders clears the now-invalid default.
+    const res = await request(app).post("/api/bot/settings").send({
+      enabledProviders: ["netease", "bilibili"],
+    });
+    expect(res.body.defaultPlatform).toBeNull();
+    expect(config.defaultPlatform).toBeNull();
+  });
 });

src/web/api/bot.ts

@@ -77,6 +77,7 @@ export function createBotRouter(
       spotify: maskedSpotify(),
       jellyfin: maskedJellyfin(),
       enabledProviders: config.enabledProviders,
+      defaultPlatform: config.defaultPlatform,
     });
   });
 
@@ -175,6 +176,29 @@ export function createBotRouter(
       );
     }
 
+    // defaultPlatform (issue #126): the operator-chosen default source for
+    // platform-less commands/REST/WebUI calls. Reconciled AFTER enabledProviders
+    // so both are validated against the same (possibly updated) enabled list:
+    //   1) Drop a stored default that the new enabledProviders no longer allows,
+    //      keeping the persisted config consistent with loadConfig's invariant.
+    //   2) Apply an explicit change — `null`/`""` clears it (back to priority
+    //      order); a known+enabled provider sets it; anything else is ignored.
+    if (config.defaultPlatform && !config.enabledProviders.includes(config.defaultPlatform)) {
+      config.defaultPlatform = null;
+    }
+    if ("defaultPlatform" in req.body) {
+      const dp = req.body.defaultPlatform;
+      if (dp === null || dp === "") {
+        config.defaultPlatform = null;
+      } else if (
+        typeof dp === "string" &&
+        (GATEABLE_PROVIDERS as readonly string[]).includes(dp) &&
+        config.enabledProviders.includes(dp as GateableProvider)
+      ) {
+        config.defaultPlatform = dp as GateableProvider;
+      }
+    }
+
     saveConfig(configPath, config);
 
     // Hot-apply the (possibly re-pointed) Jellyfin connection to the live
@@ -219,6 +243,7 @@ export function createBotRouter(
       spotify: maskedSpotify(),
       jellyfin: maskedJellyfin(),
       enabledProviders: config.enabledProviders,
+      defaultPlatform: config.defaultPlatform,
     });
   });
 

src/web/api/music.test.ts

@@ -118,6 +118,25 @@ describe("music router provider gating (enabledProviders) + jellyfin endpoints",
     expect(res.body.enabled).not.toContain("spotify"); // spotify.enabled defaults off
   });
 
+  it("GET /providers reports a configured defaultPlatform override (#126)", async () => {
+    const config = getDefaultConfig();
+    config.defaultPlatform = "qq"; // operator prefers QQ over the priority order
+    const { app } = mount(config);
+    const res = await request(app).get("/api/music/providers");
+    expect(res.status).toBe(200);
+    expect(res.body.default).toBe("qq");
+  });
+
+  it("routes a platform-less /search to the configured defaultPlatform (#126)", async () => {
+    const config = getDefaultConfig();
+    config.defaultPlatform = "bilibili";
+    const { app, netease } = mount(config);
+    const res = await request(app).get("/api/music/search?q=hello");
+    expect(res.status).toBe(200);
+    // Default is now bilibili, so the netease provider must NOT be hit.
+    expect(netease.search).not.toHaveBeenCalled();
+  });
+
   /** Default config plus the opt-in jellyfin source enabled. */
   function configWithJellyfin() {
     const config = getDefaultConfig();