module es {
    export class Timer implements ITimer{
        public context: any;
        public _timeInSeconds: number = 0;
        public _repeats: boolean = false;
        public _onTime: (timer: ITimer) => void;
        public _isDone: boolean = false;
        public _elapsedTime: number = 0;

        public getContext<T>(): T {
            return this.context as T;
        }

        public reset() {
            this._elapsedTime = 0;
        }

        public stop() {
            this._isDone = true;
        }

        public tick(){
            // 如果stop在tick之前被调用，那么isDone将为true，我们不应该再做任何事情
            if (!this._isDone && this._elapsedTime > this._timeInSeconds){
                this._elapsedTime -= this._timeInSeconds;
                this._onTime(this);

                if (!this._isDone && !this._repeats)
                    this._isDone = true;
            }

            this._elapsedTime += Time.deltaTime;

            return this._isDone;
        }

        public initialize(timeInsSeconds: number, repeats: boolean, context: any, onTime: (timer: ITimer)=>void){
            this._timeInSeconds = timeInsSeconds;
            this._repeats = repeats;
            this.context = context;
            this._onTime = onTime;
        }

        /**
         * 空出对象引用，以便在js需要时GC可以清理它们的引用
         */
        public unload(){
            this.context = null;
            this._onTime = null;
        }
    }
}