const canvas = document.getElementById('drawing-board');
const ctx = canvas.getContext('2d');
const reset = document.getElementById("reset");

robot = document.getElementById('robot');
cross = document.getElementById('cross');

const canvasOffsetX = canvas.offsetLeft;
const canvasOffsetY = canvas.offsetTop;

let scale = 2

canvas.width = window.innerWidth - canvasOffsetX * 2;
canvas.height = window.innerHeight - canvasOffsetY * 2;

//robot.style.top = canvas.height/2 - robot.height/2 - canvasOffsetY;
//robot.style.left = canvas.width/2 - robot.width/2 - canvasOffsetX;

const tr = {x: 0, y: 0, a: Math.PI}
ctx.translate(canvas.width/2 + canvasOffsetX, canvas.height/2 + canvasOffsetY)

reset.style.top = canvasOffsetY * 2 + "px";
reset.style.right = canvasOffsetX * 2 + "px";

let lineWidth = 2;
let strokeColor = "red"
let drawings = [];

ctx.lineWidth = lineWidth;
ctx.lineCap = 'square';
ctx.strokeStyle = strokeColor;
ctx.fillStyle = "red";

const wall = (element) => {
    ctx.fillRect(element.x * canvas.width - canvasOffsetX - robot.offsetWidth/2, element.y * canvas.height - canvasOffsetY, robot.offsetWidth, 5);
    ctx.stroke();
    ctx.beginPath();
}

canvas.addEventListener('mousedown', (e) => {
    cross.style.visibility = "visible";

    cross.style.left = e.layerX - canvasOffsetX + "px"
    cross.style.top = e.layerY - canvasOffsetY + "px"

    moveTo(-(e.layerX - canvasOffsetX - canvas.width/2) * scale, -(e.layerY - canvasOffsetY - canvas.height/2) * scale)

    tr.a = Math.atan((e.layerX - document.querySelector('body').clientWidth/2)/(e.layerY - document.querySelector('body').clientHeight/2))
    if ( e.layerY < canvas.height/2 )
    {
        tr.a += Math.PI
    }
    robot.style.transform = 'translate(-50%, -50%) rotate('+ -(tr.a+Math.PI)+'rad)';

    tr.x -= 120 * Math.sin(tr.a)
    tr.y -= 120 * Math.cos(tr.a)
    // (-(e.layerX - canvasOffsetX - canvas.width/2) * scale, -(e.layerY - canvasOffsetY - canvas.height/2) * scale)
    update()
});

client.on('message', function (topic, message) {
    let val = message.toString();
    var n = parseInt(val);
    if (!isNaN(n)){
        if (n < 150){
	        drawings.push({x: ((n - 30) * Math.sin(tr.a) - tr.x)/canvas.width, y: ((n - 30) * Math.cos(tr.a) - tr.y)/canvas.height}) // add a wall
        }
	update();
    }
});

/* canvas.addEventListener('touchstart', (e) => {
    drawCross(e.targetTouches[0].layerX, e.targetTouches[0].layerY);
    // moveTo((e.targetTouches[0].layerX - canvasOffsetX - canvas.width/2) * scale, (e.targetTouches[0].layerY - canvasOffsetY - canvas.height/2) * scale)

    tr.a = Math.atan((-e.targetTouches[0].layerX + canvasOffsetX + canvas.width/2)/(e.targetTouches[0].layerY - canvasOffsetY - canvas.height/2))
    if ( e.targetTouches[0].layerY - canvasOffsetY > canvas.height/2 )
    {
        tr.a += Math.PI
    }

    // if wall detected then 
    // drawings.push({x: (canvasOffsetX - robot.width/2)/canvas.width, y: -(20 * scale + canvasOffsetY + robot.height)/canvas.height, tr: {x: tr.x, y: tr.y, a: tr.a}}) // add a wall
    
    update()
});
 */

reset.onclick = () => {
    drawings = [];
    tr.x = 0
    tr.y = 0
    tr.a = 0

    robot.style.transform = 'translate(-50%, -50%) rotate(0deg)';
    update();
}

function resizeCanvas() {
    canvas.width = window.innerWidth - canvasOffsetX * 2;
    canvas.height = window.innerHeight - canvasOffsetY * 2;
    ctx.strokeStyle = strokeColor;
    ctx.lineWidth = lineWidth;
    ctx.lineCap = 'round';
    ctx.fillStyle = "red";
    robot.style.top = canvas.height/2 - robot.height/2 - canvasOffsetY;
    robot.style.left = canvas.width/2 - robot.width/2 - canvasOffsetX;
    ctx.setTransform(1, 0, 0, 1, 0, 0);
}

function redrawCanvas(){
    ctx.translate(canvas.width/2 + canvasOffsetX, canvas.height/2 + canvasOffsetY)
    drawings.forEach(element => {
        //ctx.translate(tr.x, tr.y)
        // ctx.translate(element.tr.x, element.tr.y)
        wall(element);
	// element.tr.x = tr.x
	// element.tr.y = tr.y
    });
}

function update(){
    resizeCanvas();
    redrawCanvas();
}

const updateOnFrame = () => {
    update();
    requestAnimationFrame(updateOnFrame)
}

//updateOnFrame();
window.onresize = update;