export class EventHandlers<Key, Callback extends CallableFunction> {
  private callbacks = new Map<Key, Set<Callback>>();

  add(key: Key, callback: Callback): void {
    if (this.callbacks.has(key)) {
      this.callbacks.get(key)!.add(callback);
    } else {
      this.callbacks.set(key, new Set([callback]));
    }
  }

  remove(key: Key, callback: Callback): boolean {
    if (this.callbacks.has(key)) {
      return this.callbacks.get(key)!.delete(callback);
    }
    return false;
  }

  async call(key: Key, ...args: unknown[]): Promise<void> {
    if (this.callbacks.has(key)) {
      for (const callback of this.callbacks.get(key)!) {
        await callback(...args);
      }
    }
  }
}