import { __private, _decorator, Component, EventTarget, Node } from 'cc';
import { GameEventArgMap, GameEventCallbackMap } from '../Events/GameEvent';
const { ccclass, property } = _decorator;

@ccclass('EventManger')
export class EventManger extends Component {
    //singleton
    private static _instance: EventManger = null;
    public static get instance(): EventManger {
        if (!EventManger._instance) {
            EventManger._instance = new EventManger('EventManger');
        }
        return EventManger._instance;
    }

    private _eventTarget = new EventTarget();

    onLoad() {
        if (!EventManger._instance) {
            EventManger._instance = this;
        }
    }

    public on<K extends keyof GameEventCallbackMap>(
        eventType: K,
        callback: GameEventCallbackMap[K],
        target?: any,
    ): GameEventCallbackMap[K] {
        return this._eventTarget.on(eventType, callback, target);
    }

    public off<K extends keyof GameEventCallbackMap>(
        eventType: K,
        callback: GameEventCallbackMap[K],
        thisArg?: any,
    ): GameEventCallbackMap[K] {
        return this._eventTarget.on(eventType, callback, thisArg);
    }

    public emit<K extends keyof GameEventArgMap>(eventType: K, arg: GameEventArgMap[K]) {
        if (Array.isArray(arg)) {
            this._eventTarget.emit(eventType, ...arg);
        } else {
            this._eventTarget.emit(eventType, arg);
        }
    }
}