/*
* Author:      Marco Kuiper (http://www.marcofolio.net/)
*/

// Speed of the automatic slideshow
var slideshowSpeed = 6000;
var transitionSpeed = 2000;

// Variable to store the images we need to set as background
// which also includes some text and url's.
var photos = [ {
		"title" : "Armoire",
		"image" : "home_bg_1.jpg"
	}, {
		"title" : "Table",
		"image" : "home_bg_2.jpg"
	}, {
		"title" : "Gold Girls",
		"image" : "home_bg_3.jpg"
	}, {
		"title" : "Clock",
		"image" : "home_bg_4.jpg"
	}, {
		"title" : "Mirror",
		"image" : "home_bg_5.jpg"
	}, {
		"title" : "Bed",
		"image" : "home_bg_6.jpg"
	}, {
		"title" : "Bellows",
		"image" : "home_bg_7.jpg"
	}
];
/*
	Don't need to preload the first two images since they 
	load automatically in the HTML
*/
var photosToPreload = [
	"/img/home_bg_2.jpg",				   
	"/img/home_bg_3.jpg",
	"/img/home_bg_4.jpg",
	"/img/home_bg_5.jpg",
	"/img/home_bg_6.jpg",
	"/img/home_bg_7.jpg"					   
];

/*
	Javascript Preloader from
	http://warpspire.com/tipsresources/interface-scripting/image-preloading-revisited/

*/
var Preloader = {
  callbacks: [],
  images: [],
  loadedImages: [],
  imagesLoaded: 0,

  add: function(image){
    if (typeof image == 'string') this.images.push(image);
    if (typeof image == 'array' || typeof image == 'object'){
      for (var i=0; i< image.length; i++){
        this.images.push(image[i]);
      }
    }
  },
  onFinish: function(func){
    if (typeof func == 'function') this.callbacks.push(func);
    if (typeof func == 'array' || typeof func == 'object'){
      for (var i=0; i< func.length; i++){
        this.callbacks.push(func[i]);
      }
    }
  },
  load: function(){
    for(var i=0; i<this.images.length; i++){
      this.loadedImages[i] = new Image();
      this.loadedImages[i].onload = function(){ Preloader.checkFinished.apply(Preloader) }
      this.loadedImages[i].src = this.images[i];
    }
  },

  checkFinished: function(){
    this.imagesLoaded++;
    if (this.imagesLoaded == this.images.length) this.fireFinish();
  },
  fireFinish: function(){
    for (var i=0; i<this.callbacks.length; i++){
      this.callbacks[i]();
    }
    this.images = [];
    this.loadedImages = [];
    this.imagesLoaded = 0;
    this.callbacks = [];
  }
}

$(document).ready(function() {
		
	// Backwards navigation
	$("#back").click(function() {
		stopAnimation();
		navigate("back");
	});
	
	// Forward navigation
	$("#next").click(function() {
		stopAnimation();
		navigate("next");
	});
	
	var interval;
	$("#control").toggle(function(){					  
		stopAnimation();
	}, function() {
		// Change the background image to "pause"
		$(this).css({ "background-image" : "url(/img/btn_pause.png)" });
		
		// Show the next image
		navigate("next");
		
		// Start playing the animation
		interval = setInterval(function() {
			navigate("next");
		}, slideshowSpeed);
	});
	
	
	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(photoObject, currentContainer, activeContainer) {
		animating = true;
		
		// Make sure the new container is always on the background
		currentZindex--;
		
		// Set the background image of the new active container
		$("#headerimg" + activeContainer).css({
			"background-image" : "url(/img/" + photoObject.image + ")",
			"display" : "block",
			"z-index" : currentZindex
		});
		
		// Fade out the current container
		// and display the header text when animation is complete
		$("#headerimg" + currentContainer).fadeOut(transitionSpeed, function() {
			setTimeout(function() {
				animating = false;
			}, 500);
		});
	};
	
	var stopAnimation = function() {
		// Change the background image to "play"
		$("#control").css({ "background-image" : "url(/img/btn_play.png)" });
		
		// Clear the interval
		clearInterval(interval);
	};
	
	// Preload images
	Preloader.add(photosToPreload);
	// Modified the original script to only begin animation once 
	// preloading has occurred
	Preloader.onFinish([
			// First manually navigate to the 2nd image
			navigate("next"),
			// Then begin the persistant animation
			interval = setInterval(function() {
				navigate("next");
			}, slideshowSpeed)
						]);
	Preloader.load();	
	
});