/*
JavaScript for the demo: Recreating the Nikebetterworld.com Parallax Demo
Demo: Recreating the Nikebetterworld.com Parallax Demo
Author: Ian Lunn
Author URL: http://www.ianlunn.co.uk/
Demo URL: http://www.ianlunn.co.uk/demos/recreate-nikebetterworld-parallax/
Tutorial URL: http://www.ianlunn.co.uk/blog/code-tutorials/recreate-nikebetterworld-parallax/

License: http://creativecommons.org/licenses/by-sa/3.0/ (Attribution Share Alike). Please attribute work to Ian Lunn simply by leaving these comments in the source code or if you'd prefer, place a link on your website to http://www.ianlunn.co.uk/.

Dual licensed under the MIT and GPL licenses:
http://www.opensource.org/licenses/mit-license.php
http://www.gnu.org/licenses/gpl.html
*/

$(document).ready(function() { //when the document is ready...


	//save selectors as variables to increase performance
	var $window = $(window);
	var $firstBG = $('#intro');
	var $secondBG = $('#second');
	var $thirdBG = $('#third');
	var $fourthBG = $('#fourth');
	var $people = $('#second .fg');
	var $state = 'disconnected';

	var windowHeight = $window.height(); //get the height of the window


	//apply the class "inview" to a section that is in the viewport
	$('#intro, #second, #third, #fourth').bind('inview', function (event, visible) {
			if (visible == true) {
			$(this).addClass("inview");
			} else {
			$(this).removeClass("inview");
			}
		});


	//function that places the navigation in the center of the window
	function RepositionNav(){
		var windowHeight = $window.height(); //get the height of the window
		var navHeight = $('#nav').height() / 2;
		var windowCenter = (windowHeight / 2);
		var newtop = windowCenter - navHeight;
		$('#nav').css({"top": newtop}); //set the new top position of the navigation list
	}

	//function that is called for every pixel the user scrolls. Determines the position of the background
	/*arguments:
		x = horizontal position of background
		windowHeight = height of the viewport
		pos = position of the scrollbar
		adjuster = adjust the position of the background
		inertia = how fast the background moves in relation to scrolling
	*/
	function newPos(x, windowHeight, pos, adjuster, inertia){
		return x + "% " + (-((windowHeight + pos) - adjuster) * inertia)  + "px";
	}

	//function to be called whenever the window is scrolled or resized
	function Move(){
		var pos = $window.scrollTop(); //position of the scrollbar

		//if the first section is in view...
		if($firstBG.hasClass("inview")){
			//call the newPos function and change the background position
			$firstBG.css({'backgroundPosition': newPos(50, windowHeight, pos, 550, 0.3)});
		}

		//if the second section is in view...
		if($secondBG.hasClass("inview")){
			//call the newPos function and change the background position
			$secondBG.css({'backgroundPosition': newPos(50, windowHeight, pos, 100, 0.3)});
			$people.css({'backgroundPosition': newPos(50, windowHeight, pos, 2150, 0.5)});
		}

		//if the third section is in view...
		if($thirdBG.hasClass("inview")){
			//call the newPos function and change the background position
			$thirdBG.css({'backgroundPosition': newPos(50, windowHeight, pos, 2700, 0.3)});
		}

		//if the fourth section is in view...
		if($fourthBG.hasClass("inview")){
			//call the newPos function and change the background position
			$fourthBG.css({'backgroundPosition': newPos(50, windowHeight, pos, 1550, 0.3)});
		}
	}

	// Update iPhone network list
	function Update(){
	    var iphone = document.getElementById("iphone");
	    var pos = $window.scrollTop();
	    var rem = Math.floor((new Date()).getSeconds() / 5) % 3;
	    var id  = 4;

		if ($state == 'disconnected') {
		    iphone.src = 'images/iphone_start.png';
		} else if ($state == 'connected') {
		    iphone.src = 'images/iphone_wifi.png';
		} else if ($state == 'scanning') {
			id += rem;
			iphone.src = 'images/iphone_net' + id + '.png';
		}

		window.setTimeout(Update, 1000);
	}

	RepositionNav(); //Reposition the Navigation to center it in the window when the script loads

	$window.resize(function(){ //if the user resizes the window...
		Move(); //move the background images in relation to the movement of the scrollbar
		//Update();
		RepositionNav(); //reposition the navigation list so it remains vertically central
	});

	$window.bind('scroll', function(){ //when the user is scrolling...
		Move(); //move the background images in relation to the movement of the scrollbar
		//Update();
	});

	window.setTimeout(function() { // Connect the Wi-Fi 0.8 seconds after page is loaded
		$state = 'connected';
	}, 800);

	window.setTimeout(function() { // Go into Wi-Fi menu 3.8 seconds after page is loaded
		$state = 'scanning';
	}, 3800);

	window.setTimeout(Update, 1000);
});