game-engine/modules/event-emitter.js

export class EventEmitter {
  static instance;
  events;

  constructor() {
    if (!EventEmitter.instance) {
      EventEmitter.instance = this;
      this.events = {};
    }
    return EventEmitter.instance;
  }

  on(eventName, callback) {
    if (!this.events[eventName]) {
      this.events[eventName] = [];
    }
    this.events[eventName].push(callback);
  }

  emit(eventName, ...args) {
    if (this.events[eventName]) {
      this.events[eventName].forEach((callback) => {
        callback(...args);
      });
    }
  }
}