const MAX_SPEED = 20;
const MAX_JUMP = 2;
const G = 500;

class Box {
    constructor() {
        this.position = 0;
        this.speed = 0;
        this.size = 100;
        this.jumpCounter = MAX_JUMP;
    }

    drawOn(canvas) {
        let ctx = canvas.getContext('2d');

        ctx.fillStyle = 'rgb(0, 0, 0)';
        ctx.beginPath();
        ctx.rect(
            canvas.width / 2.0 - this.size / 2.0,
            canvas.height - this.size - this.position,
            this.size,
            this.size
        );

        ctx.fill();

    }

    update(time = 0.002) {
        this.speed -= G * time;
        this.speed = Math.max(this.speed, -MAX_SPEED);
        this.position += this.speed;

        if (this.position <= 0) {
            this.position = 0;
            this.speed = 0;
            this.jumpCounter = MAX_JUMP;
        }

    }

    jump() {
        if (this.jumpCounter > 0) {
            this.jumpCounter--;
            this.speed = MAX_SPEED;
        }
    }
}