type VideoControlState = {
  playing: boolean;
  muted: boolean;
};

type Listener = (state: VideoControlState) => void;

let state: VideoControlState = {
  playing: false,
  muted: false,
};

const listeners = new Set<Listener>();

function emit() {
  listeners.forEach((listener) => listener(state));
}

export function getVideoControlState(): VideoControlState {
  return state;
}

export function subscribeVideoControls(listener: Listener): () => void {
  listeners.add(listener);
  listener(state);
  return () => listeners.delete(listener);
}

export function setVideoPlaying(playing: boolean): void {
  if (state.playing === playing) return;
  state = { ...state, playing };
  emit();
}

export function setVideoMuted(muted: boolean): void {
  if (state.muted === muted) return;
  state = { ...state, muted };
  emit();
}

export function initializeVideoControls(next: Partial<VideoControlState>): void {
  const updated: VideoControlState = {
    playing: next.playing ?? state.playing,
    muted: next.muted ?? state.muted,
  };
  if (updated.playing === state.playing && updated.muted === state.muted) return;
  state = updated;
  emit();
}