(function($){	
/*
Dependends on: jscrollpane - http://jscrollpane.kelvinluck.com - installed in ../js/plugins.js
*/
var $window = $(window); // cache window object
var $prx_master; // cache master div of plugin
var $scroll_bar; // cache scroll bar 
var promo_width = 1280; // default value for promo width
var num_promos = 3; // the total number of promos defined in DOM
var num_layers = 4;
var site_width = 980; // default value only
var prxPerc; // contains 1% of the scroll in px
var jScrollApi = Object();
var maxScroll = 0; // maximum scroll value of scroll bar
var aniCount = 0; // various animation vars
var aniTimer;
var timer_is_on = false;
var aniWait = 4500;
var aniDuration = 1300;
var snapped = true;
var initAni;
var currentPos = 0;
var snapping = false; // used to disable snapping when snapping

/* Initiate PRX plugin */
$.fn.prxInit = function(scrollBar, s_width, p_width){
    $prx_master = $(this);
    $scroll_bar = scrollBar;
    site_width = s_width;
	promo_width = p_width;
    getSetValues();
    createScrollBar($scroll_bar, $prx_master);

	/* CTA hover function for any promo */
    $prx_master.find('.promo-cta').hover(
    	function(){
    		var id = $(this).data('promo-hover');
    		$('#'+id).addClass('hover');
    	},
    	function(){
    		var id = $(this).data('promo-hover');
    		$('#'+id).removeClass('hover');
    	}
    ); 
};

/* Create a scrollable bar
------------------------------------------------------------------------- */
function createScrollBar($scroll_bar, $prx_master){

	$scroll_bar.jScrollPane(
    	{
			showArrows: true,
			verticalArrowPositions: 'split',
			horizontalArrowPositions: 'split',
			contentWidth: $prx_master.width(), // set fake width of content - very important!!!
			horizontalGutter: 20,
			animateDuration: aniDuration,
			autoReinitialise: false,
			hideFocus: false
		}
    );
   
    jScrollApi = $scroll_bar.data('jsp');
    
    $('#prx-layer1').css('left', '0px');
	$('#prx-layer2').css('left', '0px');
	$('#prx-layer3').css('left', '0px');
	$('#prx-layer4').css('left', '0px');
}

/* Animation 
------------------------------------------------------------------------- */
function parrallax(scrollPositionX){
	
	perc = scrollPositionX/(maxScroll/100); // scroll bar position as percentage
	var prxPos = Math.round(prxPerc*perc); // new prx position in pixels
	
	$('#prx-layer1').css('left', '-'+prxPos+'px');
	$('#prx-layer2').css('left', '-'+(prxPos*1.2)+'px'); // 20% faster
	$('#prx-layer3').css('left', '-'+(prxPos*1.4)+'px'); // 40% faster
	$('#prx-layer4').css('left', '-'+(prxPos*1.6)+'px'); // 60% faster	
	snapped = false;
}

/* The primary scroll event
------------------------------------------------------------------------- */
$('#home-scrollbar').bind('jsp-scroll-x',
	function(event, scrollPositionX){				
		parrallax(scrollPositionX);	
	}
);

/* Fire after scroll bar has been initialised
------------------------------------------------------------------------- */
$('#home-scrollbar').bind('jsp-initialised',
	function(event, isScrollable){				
		initAni = setTimeout(function(){ doTimer(); }, 0); // initate timer
	}
);

/* Setup default values and styles
------------------------------------------------------------------------- */
function getSetValues(){
	timer_is_on = false;
	snapped = true;
	currentPos = 0;
	num_promos = $prx_master.data('num-promos');
	num_layers = $prx_master.data('num-layers');
	var win_width = $window.width();
	var min_width = num_promos*promo_width; // minimum width of master div
	
	/* Check to see if window is smaller than a promo width */
	if(win_width < promo_width){
		
		$prx_master.width(min_width+'px'); // set a fixed width
		var offset = (promo_width-win_width)/2;
		$prx_master.css('left', '-'+offset+'px'); // offset the prx container to center it in small window

		maxScroll = min_width-$scroll_bar.width(); // defines the scrollable area inside the scroll pane
		prxPerc = (promo_width*(num_promos-1))/100; // 1% of prx master scroll in pixels

	}else{
		$prx_master.width((num_promos*100)+'%'); // set a relative width
		prxPerc = (win_width*(num_promos-1))/100; // 1% of prx master scroll in pixels
		maxScroll = $prx_master.children('#prx-layer1').width()-$scroll_bar.width(); // defines the scrollable area inside the scroll pane
		$prx_master.css('left', '0px'); // counter offset, going from small to larger window
	}
	//TODO: generate ALL necessary styles dynamically
}

/* Listen for window resize to update/reset stuff
------------------------------------------------------------------------- */
var w_wid = $(window).width();
var h_wid = $(window).height(); 
var reset_delay;
	
$(window).resize(function(){ 
	if(w_wid !== $(this).width() || h_wid !== $(this).height()){
		w_wid = $(this).width();
		h_wid = $(this).height();
		clearTimeout(reset_delay);
		reset_delay = setTimeout(function(){ reset(); }, 100); // only resize after finished resizing
	}
});		
	
function reset(){
	$window = $(window);
	killTimer();
	
	if(jScrollApi.reinitialise){
		getSetValues();	
		jScrollApi.destroy(); // Kill scrollbar and re-apply
 		createScrollBar($('#home-scrollbar'), $('#prx-master'));
	 	$('#home-scrollbar').bind('jsp-scroll-x',
			function(event, scrollPositionX, scrollPercentageX){				
				parrallax(scrollPositionX, scrollPercentageX);		
			}
		);
	}
}

/* Snap and kill timer controls 
------------------------------------------------------------------------- */
$(document).mouseup(function(){ if(!snapped && !snapping){ snapPromos(); } });
$('#home-scrollbar').click(function(){ killTimer(); });
$('#home-scrollbar').mouseover(function(){ killTimer(); });

/* Snap promos so one is features/centered
------------------------------------------------------------------------- */
function snapPromos(target){
	if(jScrollApi.getPercentScrolledX() !== 0 && jScrollApi.getPercentScrolledX() !== 1){
		snapping = true;
		var perc = (getSnapPosition(jScrollApi.getPercentScrolledX())/100);
		jScrollApi.scrollToPercentX(perc, true);
		setTimeout(function(){ snapping = false; snapped = true; }, (aniDuration+50)); // set back to true after animation
	}
}

/* Find next closest snap position
------------------------------------------------------------------------- */
function getSnapPosition(scrollPercentage){	
	var divisions = 100/($prx_master.data('num-promos')-1);
	if(scrollPercentage > (currentPos/100)){
	 	currentPos = currentPos+divisions; 		
	 }else{
		currentPos = currentPos-divisions;
	}
	return currentPos;
}

/* Auto scroll timer - infinite loop
------------------------------------------------------------------------- */
var aniDir = 'right';
function timedCount(){

	var increment = 0.5; // TODO: 0.5 should be dynamic, only suitable for 3 promos!!!
	if(timer_is_on){
		
		currentPos = (aniCount*100);
	
		jScrollApi.scrollToPercentX(aniCount, true);
		aniTimer = setTimeout(function (){ timedCount(); }, aniWait);
		
		if(aniCount >= 1){ aniDir = 'left';	} // TODO: fix these shody conditions
		if(aniCount <= 0){ aniDir = 'right'; }
		if(aniDir === 'right'){
			aniCount += increment;
		}else{
			aniCount -= increment;
		}
		
	}else{
		killTimer();
	}
}

/* Go timer
------------------------------------------------------------------------- */
function doTimer(){
	if (!timer_is_on){
	  	timer_is_on = true;
	  	timedCount();
	}
}

/* Kill the auto timer
------------------------------------------------------------------------- */
function killTimer(){
	clearTimeout(aniTimer);
	aniTimer = null;
	timer_is_on = false;
	aniCount = 0;
	clearTimeout(initAni);
}

/* Stop right there */
}(jQuery))