/**
 * Copyright (c) Double Symmetry GmbH
 * Commercial use requires a license. See https://rntp.dev/pricing
 */

type Listener = (payload: unknown) => void;

export interface EventSubscription {
  remove(): void;
}

/**
 * Minimal typed event emitter for the web backend. `src/audio.ts` routes
 * `addEventListener` here on web instead of `NativeEventEmitter`, so events
 * work regardless of react-native-web's emitter internals.
 */
export class EventBus {
  private listeners = new Map<string, Set<Listener>>();

  addListener(event: string, listener: Listener): EventSubscription {
    let set = this.listeners.get(event);
    if (!set) {
      set = new Set();
      this.listeners.set(event, set);
    }
    set.add(listener);
    return {
      remove: () => {
        this.listeners.get(event)?.delete(listener);
      },
    };
  }

  emit(event: string, payload: unknown): void {
    this.listeners.get(event)?.forEach((listener) => {
      try {
        listener(payload);
      } catch (e) {
        console.error(`@rntp/player: error in '${event}' listener`, e);
      }
    });
  }

  removeAllListeners(): void {
    this.listeners.clear();
  }
}