import { useSyncExternalStore } from 'react';
import { useAviationPlayer } from '../AviationContext';
import type { DomainEvent } from '../specs/types.nitro';
import type { AviationPlayer } from '../Aviation';

/**
 * React hook that surfaces the player's last audio interruption — a phone
 * call, focus loss, Siri. Pair with `player.setInterruptionMode` when the
 * UI needs to explain what happened ("Resuming after call…") or offer
 * manual controls under the 'pause' policy.
 *
 * Returns `undefined` until an interruption occurs; re-renders only when a
 * new interruption arrives. The event's `began` flag distinguishes start
 * from end; `resumePolicy` reports the policy in effect at that moment.
 *
 * Interruptions only react — they never request focus. A player that
 * deactivated itself (autoDeactivateOnQueueEnd) stays quiet.
 *
 * @example
 * ```tsx
 * function CallBanner() {
 *   const interruption = useInterruption();
 *   if (!interruption?.began) return null;
 *   return <Text>Paused for phone call…</Text>;
 * }
 * ```
 */
export function useInterruption(
  playerArg?: AviationPlayer
): DomainEvent | undefined {
  const player = useAviationPlayer(playerArg);
  return useSyncExternalStore(
    player.store.subscribeInterruption,
    () => player.store.lastInterruption
  );
}