class KeyboardInput {

	constructor() {
		this.keys = [];
		this.press = [];
		this.release = [];
	}

	attach() {
		for (var i = 0; i < 256; i++) {
			this.keys[i] = false;
			this.press[i] = false;
			this.release[i] = false;
		}

		window.addEventListener("keydown", (event) => {
			if (!this.keys[event.keyCode]) {
				this.press[event.keyCode] = true;
			}
			this.keys[event.keyCode] = true;
		});

		window.addEventListener("keyup", (event) => {
			if (this.keys[event.keyCode]) {
				this.release[event.keyCode] = true;
			}
			this.keys[event.keyCode] = false;
		});
	}

	isPressed(code) {
		var pressed = this.press[code] && this.keys[code];
		this.press[code] = false;
		return pressed;
	}

	isReleased(code) {
		var released = this.release[code] && !this.keys[code];
		this.release[code] = false;
		return released;
	}

	isDown(code) {
		return this.keys[code];
	}
}

window.Keys = {
	Left: 37,
	Up: 38,
	Right: 39,
	Down: 40,
	W: 87,
	A: 65,
	S: 83,
	D: 68,
	Space: 32,
	Enter: 13,
	Escape: 27
};