feat(autopause): pure occupancy-decision function

src/bot/auto-pause.ts

@@ -0,0 +1,23 @@
+export type PlayerStateName = "idle" | "playing" | "paused";
+export type OccupancyAction = "pause" | "resume" | "none";
+
+/**
+ * Decide what auto-pause should do given channel occupancy.
+ * - empty (userCount <= 0): pause iff enabled and currently playing.
+ * - re-populated (userCount > 0): resume iff we previously auto-paused and are still paused.
+ * `autoPaused` distinguishes our auto-pause from a user pause, so user pauses are never resumed.
+ */
+export function decideOccupancyAction(
+  playerState: PlayerStateName,
+  autoPaused: boolean,
+  enabled: boolean,
+  userCount: number,
+): OccupancyAction {
+  const empty = userCount <= 0;
+  if (empty) {
+    if (enabled && playerState === "playing") return "pause";
+    return "none";
+  }
+  if (autoPaused && playerState === "paused") return "resume";
+  return "none";
+}