Make video a per-server toggle instead of an env-wide setting

VIDEO_ENABLED is now permission rather than behaviour: it decides whether
the feature exists at all, while turning it on for a server is a toggle in
the panel or !video in chat, off by default. Video costs real CPU for
every playing channel, so that should be a deliberate choice rather than
something a config flag switches on everywhere.

With the env flag off the panel renders no toggle at all and !video says
so, and the switch applies from the next track — swapping tracks mid-play
would cut the current one.

The loop button no longer reads "выкл" either: it sat next to the video
button showing the same word, so the two states were indistinguishable.
Both now name what they do and rely on highlighting for state.

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

src/api/server.ts

@@ -186,6 +186,7 @@ export async function startApiServer({ manager, context }: ApiServerOptions) {
       features: {
         localLibrary: Boolean(config.LOCAL_MEDIA_DIR),
         requireListener: config.REQUIRE_LISTENER,
+        video: config.VIDEO_ENABLED,
       },
     });
   });
@@ -265,6 +266,8 @@ export async function startApiServer({ manager, context }: ApiServerOptions) {
     leave: (serverId, userId) => manager.leave(serverId, userId),
     volume: (serverId, userId, body) =>
       manager.setVolume(serverId, userId, z.object({ volume: z.number().min(0).max(200) }).parse(body).volume),
+    video: (serverId, userId, body) =>
+      manager.setVideo(serverId, userId, z.object({ enabled: z.boolean() }).parse(body).enabled),
     loop: (serverId, userId, body) =>
       manager.setLoop(serverId, userId, z.object({ mode: z.enum(["off", "track", "queue"]) }).parse(body).mode),
     seek: (serverId, userId, body) =>

src/bot/commands.ts

@@ -260,6 +260,26 @@ export const commands: Command[] = [
       await ctx.reply(`🔁 Повтор: ${loopLabel(nextMode)}`);
     },
   },
+  {
+    name: "video",
+    aliases: ["видео"],
+    usage: "video [on|off]",
+    description: "Показывать клип как демонстрацию экрана",
+    async run(ctx) {
+      if (!config.VIDEO_ENABLED) {
+        throw new UserFacingError("Видео выключено в настройках бота (VIDEO_ENABLED)");
+      }
+      const raw = (ctx.args[0] ?? "").toLowerCase();
+      const current = ctx.manager.snapshot(ctx.serverId).videoEnabled;
+      const next = raw ? ["on", "вкл", "true", "1", "да"].includes(raw) : !current;
+      await ctx.manager.setVideo(ctx.serverId, ctx.actor.id, next);
+      await ctx.reply(
+        next
+          ? "📺 Клип будет показан как демонстрация экрана — со следующего трека."
+          : "🔇 Видео выключено, играю только звук.",
+      );
+    },
+  },
   {
     name: "shuffle",
     aliases: ["sh", "перемешай"],
@@ -348,7 +368,9 @@ export const commands: Command[] = [
     usage: "help",
     description: "Показать список команд",
     async run(ctx) {
-      const lines = commands.map(
+      const lines = commands
+        .filter((command) => command.name !== "video" || config.VIDEO_ENABLED)
+        .map(
         (command) => `\`${config.COMMAND_PREFIX}${command.usage}\` — ${command.description}`,
       );
       await ctx.reply(

src/core/manager.ts

@@ -269,6 +269,10 @@ export class MusicManager extends EventEmitter<ManagerEvents> {
     (await this.require(serverId, userId)).setVolume(volume);
   }
 
+  async setVideo(serverId: string, userId: string, enabled: boolean): Promise<void> {
+    (await this.require(serverId, userId)).setVideo(enabled);
+  }
+
   async setLoop(serverId: string, userId: string, mode: LoopMode): Promise<void> {
     (await this.require(serverId, userId)).setLoop(mode);
   }
@@ -314,6 +318,7 @@ export class MusicManager extends EventEmitter<ManagerEvents> {
       volume: config.DEFAULT_VOLUME,
       loop: "off",
       shuffleUsed: false,
+      videoEnabled: false,
       updatedAt: Date.now(),
     };
   }

src/core/player.ts

@@ -66,7 +66,9 @@ export class GuildPlayer extends EventEmitter<GuildPlayerEvents> {
   current: Track | null = null;
   volume = config.DEFAULT_VOLUME;
   loop: LoopMode = "off";
-  shuffleUsed = false;
+  shuffleUsed = false;
+  /** Per-server switch for publishing the clip; the env flag gates it too. */
+  videoEnabled = false;
 
   private status: PlayerStatus = "idle";
   private readonly revoice: RevoiceLike;
@@ -113,7 +115,8 @@ export class GuildPlayer extends EventEmitter<GuildPlayerEvents> {
       history: this.history.slice(0, 10),
       volume: this.volume,
       loop: this.loop,
-      shuffleUsed: this.shuffleUsed,
+      shuffleUsed: this.shuffleUsed,
+      videoEnabled: this.videoEnabled,
       updatedAt: Date.now(),
     };
   }
@@ -307,7 +310,7 @@ export class GuildPlayer extends EventEmitter<GuildPlayerEvents> {
     this.publish();
 
     try {
-      const input = await openPlayback(track, seekSeconds);
+      const input = await openPlayback(track, seekSeconds, { video: this.videoEnabled });
       this.currentInput = input;
       this.expectingStop = false;
       await media.playStream(input.input, input.inputOptions);
@@ -464,6 +467,12 @@ export class GuildPlayer extends EventEmitter<GuildPlayerEvents> {
     this.publish();
   }
 
+  /** Takes effect on the next track: switching mid-stream would cut playback. */
+  setVideo(enabled: boolean): void {
+    this.videoEnabled = enabled;
+    this.publish();
+  }
+
   setLoop(mode: LoopMode): void {
     this.loop = mode;
     this.publish();

src/sources/index.ts

@@ -173,9 +173,14 @@ export interface PlaybackInput {
   video?: { stream: Readable; width: number; height: number };
 }
 
+export interface PlaybackOptions {
+  /** Publish the picture too; the server-wide switch still has to allow it. */
+  video?: boolean;
+}
+
 /** Only YouTube reliably carries a picture worth showing next to the audio. */
-function canShowVideo(track: Track): boolean {
-  return config.VIDEO_ENABLED && track.source === "youtube" && !track.isLive;
+function canShowVideo(track: Track, wanted: boolean): boolean {
+  return wanted && config.VIDEO_ENABLED && track.source === "youtube" && !track.isLive;
 }
 
 const HTTP_RESILIENCE = [
@@ -196,7 +201,11 @@ function ffmpegProxyOptions(): string[] {
 }
 
 /** Opens an ffmpeg-compatible input for a track, optionally starting at an offset. */
-export async function openPlayback(track: Track, seekSeconds = 0): Promise<PlaybackInput> {
+export async function openPlayback(
+  track: Track,
+  seekSeconds = 0,
+  options: PlaybackOptions = {},
+): Promise<PlaybackInput> {
   const seekOptions = seekSeconds > 0 ? ["-ss", seekSeconds.toFixed(2)] : [];
 
   if (track.source === "local") {
@@ -214,7 +223,10 @@ export async function openPlayback(track: Track, seekSeconds = 0): Promise<Playb
 
   // The format is checked before committing to the video pipeline: audio comes
   // out of that same pipeline, so falling back afterwards would kill the sound.
-  if (canShowVideo(track) && (await ytdlp.hasProgressiveVideo(track.url, config.VIDEO_HEIGHT))) {
+  if (
+    canShowVideo(track, options.video ?? false) &&
+    (await ytdlp.hasProgressiveVideo(track.url, config.VIDEO_HEIGHT))
+  ) {
     log.info({ title: track.title }, "playing with video");
     const pipeline = openVideoPipeline(track.url, seekSeconds);
     return {

src/types.ts

@@ -42,7 +42,8 @@ export interface PlayerSnapshot {
   history: Track[];
   volume: number;
   loop: LoopMode;
-  shuffleUsed: boolean;
+  shuffleUsed: boolean;
+  videoEnabled: boolean;
   updatedAt: number;
 }