windowHeight = document.documentElement.clientHeight * 3;
windowWidth = document.documentElement.clientWidth;
gravity = 200;
camera = windowHeight;
PLATFORM_WIDTH = 50;
PLATFORM_HEIGHT = 10;
PLATFORMS_DISTANCE = 150;
CAMERA_MOVE = PLATFORMS_DISTANCE - 20;

Crafty.init(windowWidth, windowHeight, document.getElementById('game'));


lvlOne();





//lvls
function lvlOne(){
	Crafty.e('Floor, 2D, Canvas, Color')
	  .attr({x: 0, y: windowHeight-20, w: windowWidth, h: 20})
	  .color('green');

	 hero = Crafty.e('2D, Canvas, Color, Twoway, Gravity')
	  .attr({x: 0, y: windowHeight-30, w: 50, h: 50})
	  .color('#F00')
	  .twoway(gravity)
	  .gravity('Floor');

	for(i = 0; i < windowHeight; i+=PLATFORMS_DISTANCE){
	  	createPlatform(i);
	  	createPlatform(i);
	  	createPlatform(i);
	  	createPlatform(i);
	}

	$('body').keyup( function(e) {
		if(e.keyCode ==  87 || e.keyCode == 38){
			$( "#game" ).animate({ "top": "+=" + CAMERA_MOVE+ "px" }, "slow" );
			camera-=(CAMERA_MOVE);
		}

		setTimeout(isAlive, 1000);

	});
}


//__________________________________________________
//usefull functions
function getRandomArbitrary(min, max) {
  return Math.random() * (max - min) + min;
}

function createPlatform(y) {
  Crafty.e('Floor, 2D, Canvas, Color')
  	.attr({x:getRandomArbitrary(0, windowWidth - PLATFORM_WIDTH), y: y, w: PLATFORM_WIDTH, h: PLATFORM_HEIGHT})
  	.color('green');
}

isAlive = function(){
	if(hero.y > camera)
		alert("DIE");
}
//move camera to start
function scrollToBottom(){
	window.scrollTo(0,camera);
}