// images preload
imagesQ={onComplete:function(){},onLoaded:function(){},current:null,qLength:0,images:[],inProcess:false,queue:[],queue_images:function(){var arg=arguments;for(var i=0;i<arg.length;i++){if(arg[i].constructor===Array){this.queue=this.queue.concat(arg[i])}else if(typeof arg[i]==='string'){this.queue.push(arg[i])}}},process_queue:function(){this.inProcess=true;this.qLength+=this.queue.length;while(this.queue.length>0){this.load_image(this.queue.shift())}this.inProcess=false},load_image:function(imageSrc){var th=this;var im=new Image;im.onload=function(){th.current=im;th.images.push(im);(th.onLoaded)();if(th.queue.length>0&&!th.inProcess){th.process_queue()}if(th.qLength==th.images.length){(th.onComplete)()}};im.src=imageSrc}}

// Speed of the automatic slideshow
var slideshowSpeed = 3000;

imagesQ.queue_images(photos);
imagesQ.process_queue();	

jQuery(document).ready(function() {
	
	var interval;
	
	var activeContainer = 1;	
	var currentImg = 0;
	var animating = false;
	var navigate = function(direction) {
		// Check if no animation is running. If it is, prevent the action
		if(animating) {
			return;
		}
		
		// Check which current image we need to show
		if(direction == "next") {
			currentImg++;
			if(currentImg == photos.length + 1) {
				currentImg = 1;
			}
		} else {
			currentImg--;
			if(currentImg == 0) {
				currentImg = photos.length;
			}
		}
		
		// Check which container we need to use
		var currentContainer = activeContainer;
		if(activeContainer == 1) {
			activeContainer = 2;
		} else {
			activeContainer = 1;
		}
		
		showImage(photos[currentImg - 1], currentContainer, activeContainer);
		
	};
	
	var currentZindex = -1;
	var showImage = function(photo, currentContainer, activeContainer) {
		animating = true;
		
		// Make sure the new container is always on the background
		currentZindex--;
		
		// Set the background image of the new active container
		jQuery("#headerimg" + activeContainer).css({
			"background-image" : "url(" + photo + ")",
			"display" : "block",
			"z-index" : currentZindex
		});	
		
		// Fade out the current container
		// and display the header text when animation is complete
		jQuery("#headerimg" + currentContainer).fadeOut(2000, function() {
			setTimeout(function() {
				animating = false;
			}, 2000);
		});
	};
	
	// We should statically set the first image
	navigate("next");
	
	// Start playing the animation
	interval = setInterval(function() {
		navigate("next");
	}, slideshowSpeed);
	
});