function inicio (QntityDisks){
	nDisks=QntityDisks;
	optimalSolution= Math.pow(2,QntityDisks)-1;
	var x = 0;
	var y = 549.5;
	var w = 330;
	start = Date.now();
	startOfMove = Date.now();
	for (var i = 0; i < QntityDisks; i++) {
		var disk = new Disk(x,y,w,40,pat[i+1]);
		towerA.push(disk);
		x+=20;  //moves to the right
		y-=41; //moves up, +1 to separate disks
		w-=40; //reduces disk width
	}
	drawScene();

}

class Disk{
	constructor(x,y,w,h,fill){
		this.x=x;
		this.y=y;
		this.w=w;
		this.h=h;
		this.fill=fill;
	}
	draw(){//(ctx, x, y, width, height, radius, fill, stroke)
		context.fillStyle = this.fill;
		context.strokeStyle = "black";
		roundRect(context, this.x, this.y, this.w, this.h, 20, 20, true);
	}
	clear(){
		context.clearRect(this.x, this.y, this.w, this.h);
	}
}
function reset (QntityDisks){
	nDisks = QntityDisks;
	towerA.splice(0,towerA.length);
	towerB.splice(0,towerB.length);
	towerC.splice(0,towerC.length);
	moves.splice(0,moves.length);
	nMovements = 0;
	nTotalMovements = 0;
	idF = " ";
	idT=" ";
	toMove=null;
	inicio(QntityDisks);
}
function drawTowers (){
	context.beginPath();
	context.fillStyle = pat[0];
	<!-- torre 1 -->
    roundRect(context, 160, 260, 20, 340, 5, pat, false);//ctx, x, y, largura, altura, radius, fill, stroke(T/F)

    <!--Base t1-->
	roundRect(context, 0, 590, 330, 20, 5, pat, false);

	<!-- torre 2 -->
	roundRect(context, 505, 260, 20, 340, 5, pat, false);

    <!--Base t2-->
	roundRect(context, 345, 590, 330, 20, 5, pat, false);

	<!-- torre 3 -->
	roundRect(context, 850, 260, 20, 340, 5, pat, false);

    <!--Base t3-->
	roundRect(context, 690, 590, 330, 20, 5, pat, false);
}

function drawDisks (){
	for(i=0; i<towerA.length; i++){
		towerA[i].draw();
	}
	for(i=0; i<towerB.length; i++){
		towerB[i].draw();
	}
	for(i=0; i<towerC.length; i++){
		towerC[i].draw();
	}
}

function drawScene (){
	context.clearRect(0, 0, canvas.width, canvas.height);
	drawTowers();
	drawDisks();
	drawFromTo();
}

function buttonClick (id){
	if(toMove == null && getTower(id).length>0){
		toMove = id;
		idF= String.fromCharCode(65+id);
		idT= " ";
		drawScene();

	} else if(toMove != null && toMove != id){
		idT = String.fromCharCode(65+id);
		moveDisk(toMove, id);
		toMove=null;
	}
}

function getTower (id){
	switch(id){
		case 0:
			return towerA;
		case 1:
			return towerB;
		case 2:
			return towerC;
	}
}

function drawFromTo (){
	context.font = "50px Arial";
	context.fillStyle = "black";
	context.fillText("Mover de "+idF+" para "+idT, 50, 50);
	context.fillText("Movimentos: "+nTotalMovements, 50, 100);
}


function moveDisk (origin, destiny){
	var originTower = getTower(origin), destinyTower = getTower(destiny), topDiskOrigin, topDiskDestiny;
	moveTime = Math.floor( (Date.now()- startOfMove) /1000);
	startOfMove = Date.now();//update start of movement
	if(nMovements< moves.length){
		moves.splice(nMovements, moves.length- nMovements);
	}
	moves.push(origin+"  "+destiny);


	nMovements++;
	finishMove(origin, destiny);
	if(towerC.length == nDisks && nDisks!=0){
		acertou=1;
		totalTime= Date.now() - start;
		if(nTotalMovements==optimalSolution){
			alert("Você ganhou com a quantidade ótima de movimentos "+optimalSolution+"!!!\nParabens!!!");
		}else{
			alert("Você ganhou com "+nTotalMovements+" movimentos sendo o minimo possível "+optimalSolution);
		}
	}
}

function roundRect(ctx, x, y, width, height, radius, fill, stroke) {
  if (typeof stroke == "undefined" ) {
    stroke = true;
  }
  if (typeof radius === "undefined") {
    radius = 5;
  }
  ctx.beginPath();
  ctx.moveTo(x + radius, y);
  ctx.lineTo(x + width - radius, y);
  ctx.quadraticCurveTo(x + width, y, x + width, y + radius);
  ctx.lineTo(x + width, y + height - radius);
  ctx.quadraticCurveTo(x + width, y + height, x + width - radius, y + height);
  ctx.lineTo(x + radius, y + height);
  ctx.quadraticCurveTo(x, y + height, x, y + height - radius);
  ctx.lineTo(x, y + radius);
  ctx.quadraticCurveTo(x, y, x + radius, y);
  ctx.closePath();
  if (stroke) {
    ctx.stroke();
  }
  if (fill) {
    ctx.fill();
  }
}

function undo(){
	if(nMovements>0){
		var res = moves[nMovements-1].split("  ");
		nMovements--;
		if (nMovements>1){
			var res2 = moves[nMovements-2].split("  ");
			idf = res2[0];
			idt = res2[1];
		} else{
			idf = "  ";
			idt = "  ";
		}
		finishMove(parseInt(res[1]), parseInt(res[0]));
	}
}

function redo(){
	if (nMovements < moves.length){
		var res = moves[nMovements].split("  ");
		nMovements++;
		finishMove(parseInt(res[0]), parseInt(res[1]));
	}
}

function finishMove(origin, destiny){
	nTotalMovements++;
	var originTower = getTower(origin), destinyTower = getTower(destiny), topDiskOrigin, topDiskDestiny;
	topDiskOrigin = originTower[originTower.length-1];
	totalMoves.push(origin+"  "+destiny+"  "+moveTime);
	if(destinyTower.length>0){
		topDiskDestiny = destinyTower[destinyTower.length-1];
		if(topDiskOrigin.w<topDiskDestiny.w){
			topDiskOrigin.x += 345*(destiny-origin);
			topDiskOrigin.y += 42*(originTower.length-destinyTower.length-1);
			originTower.pop();
			destinyTower.push(topDiskOrigin);
			drawScene();
		} else{
			nWrongMoves++;
			alert("Movimento Inválido");
			idF =" ";
			idT =" ";
			drawScene();
		}
	}else{
		topDiskOrigin.x += 345*(destiny-origin);
		topDiskOrigin.y += 42*(originTower.length-destinyTower.length-1);
		originTower.pop();
		destinyTower.push(topDiskOrigin);
		drawScene();
	}
}