class Countdown {
    constructor(duration, onTick, onFinish) {
        this.duration = duration;
        this.timeLeft = duration;
        this.onTick = onTick;
        this.onFinish = onFinish;
        this.timer = null;
    }

    start() {
        this.stop();

        this.timeLeft = this.duration;
        this.onTick?.(this.timeLeft);

        this.timer = setInterval(() => {
            this.timeLeft--;
            this.onTick?.(this.timeLeft);

            if(this.timeLeft <= 0) {
                this.stop();
                this.onFinish();
            }
        }, 1000);
    }

    stop() {
        if(this.timer) {
            clearInterval(this.timer);
        }

        this.timer = null;
    }

    reset() {
        this.start();
    }
}