LightboxOptions = Object.extend({
    fileLoadingImage:        '',
    fileBottomNavCloseImage: '',

    overlayOpacity: 0.8,   // controls transparency of shadow overlay

    animate: true,         // toggles resizing animations
    resizeSpeed: 7,        // controls the speed of the image resizing animations (1=slowest and 10=fastest)

    borderSize: 10,         //if you adjust the padding in the CSS, you will need to update this variable

	// When grouping images this is used to write: Image # of #.
	// Change it for non-english localization
	labelImage: "Image",
	labelOf: "of"
}, window.LightboxOptions || {});


var ImageViewer = Class.create({
    initialized: false,
    //imageArray: [],
    activeImage: 0,
    width: 400,
    height: 300,
    scaleNumber: 10,
    slider: undefined,
    
    // initialize()
    // Constructor runs on completion of the DOM loading. Calls updateImageList and then
    // the function inserts html at the bottom of the page which is used to display the shadow 
    // overlay and the image container.
    //
    initialize: function() 
    {    
    },
    
    startInitialize : function()
    {
        if(this.initialized == false)
        {
            this.slider = null;
            this.keyboardAction = this.keyboardAction.bindAsEventListener(this);

            if (LightboxOptions.resizeSpeed > 10) LightboxOptions.resizeSpeed = 10;
            if (LightboxOptions.resizeSpeed < 1)  LightboxOptions.resizeSpeed = 1;

	        this.resizeDuration = LightboxOptions.animate ? ((11 - LightboxOptions.resizeSpeed) * 0.1) : 0;
	        this.overlayDuration = LightboxOptions.animate ? 0.2 : 0;  // shadow fade in/out duration

            // When Lightbox starts it will resize itself from 250 by 250 to the current image dimension.
            // If animations are turned off, it will be hidden as to prevent a flicker of a
            // white 250 by 250 box.
            var size = (LightboxOptions.animate ? 250 : 1) + 'px';
            
            var objBody = $$('body')[0];

		    objBody.appendChild(Builder.node('div',{id:'overlay'}));
    	
            objBody.appendChild(Builder.node('div',{id:'lightbox'}, [
                Builder.node('div',{id:'outerImageContainer'}, 
                    Builder.node('div',{id:'imageContainer'}, [
                        Builder.node('div', {id: 'imageBox'}, [
                            Builder.node('img',{id:'lightboxImage'}), 
                            Builder.node('div',{id:'hoverNav'}, [
                                Builder.node('a',{id:'prevLink', href: 'javascript:void(0);' }),
                                Builder.node('a',{id:'nextLink', href: 'javascript:void(0);' }),
                                Builder.node('div', {id:'zoomSlider'}, [
                                    Builder.node('div', {id: 'zoomSliderLeft'}),
                                    Builder.node('div', {id:'zoomHandle'}),
                                    Builder.node('div', {id: 'zoomSliderRight'}),
                                ])
                            ])
                        ]),
                        Builder.node('div',{id:'loading'}, 
                            Builder.node('a',{id:'loadingLink', href: 'javascript:void(0);' }, 
                                Builder.node('img', {src: LightboxOptions.fileLoadingImage})
                            )
                        )
                    ])
                ),
                Builder.node('div', {id:'imageDataContainer'},
                    Builder.node('div',{id:'imageData'}, [
                        Builder.node('div',{id:'imageDetails'}, [
                            Builder.node('span',{id:'caption'}),
                            Builder.node('span',{id:'numberDisplay'})
                        ]),
                        Builder.node('div',{id:'bottomNav'},
                            Builder.node('a',{id:'bottomNavClose', href: 'javascript:void(0);' },
                                Builder.node('img', { src: LightboxOptions.fileBottomNavCloseImage })
                            )
                        )
                    ])
                )
            ]));

		    prototypeJs('overlay').hide().observe('click', (function() { this.end(); }).bind(this));
		    prototypeJs('lightbox').hide().observe('click', (function(event) { if (event.element().id == 'lightbox') this.end(); }).bind(this));
		    prototypeJs('outerImageContainer').setStyle({ width: size, height: size });
		    prototypeJs('prevLink').observe('click', (function(event) { event.stop(); this.changeImage(this.activeImage - 1); }).bindAsEventListener(this));
		    prototypeJs('nextLink').observe('click', (function(event) { event.stop(); this.changeImage(this.activeImage + 1); }).bindAsEventListener(this));
		    prototypeJs('loadingLink').observe('click', (function(event) { event.stop(); this.end(); }).bind(this));
		    prototypeJs('bottomNavClose').observe('click', (function(event) { event.stop(); this.end(); }).bind(this));

            var th = this;
            var ids = 
                'overlay lightbox outerImageContainer imageContainer imageBox lightboxImage hoverNav prevLink nextLink loading loadingLink ' + 
                'imageDataContainer imageData imageDetails caption numberDisplay bottomNav bottomNavClose zoomSlider zoomHandle';   
            $w(ids).each(function(id){ th[id] = prototypeJs(id); });
            
            this.initialized = true;
        }
    },
    
    //
    //  start()
    //  Display overlay and lightbox. If image is part of a set, add siblings to imageArray.
    //
    start: function(width, height, scaleNumber, images) {    
    
        var arrayPageSize = this.getWindowSize();

        this.imageArray = images;
        this.width = width;
        this.height = height;
        this.scaleNumber = scaleNumber;

        this.startInitialize();   
   
        selectedImage = this.lightboxImage;
        box = this.imageBox;
        boxWidth = this.width;
        boxHeight = this.height;

        this.imageBox.style.width = this.width + 'px';
        this.imageBox.style.height = this.height + 'px';

        new Draggable(this.lightboxImage, {revert: false,
            snap : (function(x, y, draggable) {  
                return this.getBounds(x, y);
            }).bind(this)
        });
        
        $$('select', 'object', 'embed').each(function(node){ node.style.visibility = 'hidden' });

        // stretch overlay to fill page and fade in
        prototypeJs('overlay').setStyle({ width: arrayPageSize[0] + 'px', height: arrayPageSize[1] + 'px' });

        new Effect.Appear(this.overlay, { duration: this.overlayDuration, from: 0.0, to: LightboxOptions.overlayOpacity });

        var imageNum = 0;       

        // calculate top and left offset for the lightbox 
        var arrayPageScroll = document.viewport.getScrollOffsets();
        var lightboxTop = arrayPageScroll[1] + (document.viewport.getHeight() / 10);
        var lightboxLeft = arrayPageScroll[0];
        this.lightbox.setStyle({ top: lightboxTop + 'px', left: lightboxLeft + 'px' }).show();
        
        this.resizeImageContainer(this.width, this.height);

        this.changeImage(imageNum);
    },

    getBounds: function(x, y)
    {
        var size = [parseInt(this.lightboxImage.style.width), parseInt(this.lightboxImage.style.height)];
        
        var minX = this.width - size[0];
        var minY = this.height - size[1];
        var maxX = 0;
        var maxY = 0;
        
        var outX = (x >= maxX) ? maxX :
                (x <= minX) ? minX : x;
        
        var outY = (y >= maxY) ? maxY :
                (y <= minY) ? minY : y;
        
        if(size[0] <= this.width)
            outX = (this.width - size[0]) / 2;
        
        if(size[1] <= this.height)
            outY = (this.height - size[1]) / 2;
        
        return [outX, outY];
    },
    
    getImagePosition : function()
    {
        return [parseInt(this.lightboxImage.style.left), parseInt(this.lightboxImage.style.top)];
    },
    
    //
    //  changeImage()
    //  Hide most elements and preload image in preparation for resizing image container.
    //
    changeImage: function(imageNum) {   
        
        if(this.slider != null)
            this.slider.setValue(0);
        
        this.activeImage = imageNum; // update global var

        // hide elements during transition
        if (LightboxOptions.animate) this.loading.show();
        this.lightboxImage.hide();
        this.hoverNav.hide();
        this.prevLink.hide();
        this.nextLink.hide();
		// HACK: Opera9 does not currently support scriptaculous opacity and appear fx
        this.imageDataContainer.setStyle({opacity: .0001});
        this.numberDisplay.hide();      
        
        var imgPreloader = new Image();
        
        // once image is preloaded, resize image container
        imgPreloader.onload = (function(){
            this.lightboxImage.src = this.imageArray[this.activeImage][0];
            if(this.imageArray[this.activeImage].length == 2)
                this.imageArray[this.activeImage].push(imgPreloader);
                
            this.showImage();
            //this.resizeImageContainer(imgPreloader.width, imgPreloader.height);
        }).bind(this);
        
        imgPreloader.src = this.imageArray[this.activeImage][0];
    },
    
    getCurrentCenter : function()
    {
        var imageHeight = parseInt(this.lightboxImage.style.height);
        
        var centreX = 0.5;
        if(!isNaN(this.lightboxImage.style.width))
        {
            var imageWidth = parseInt(this.lightboxImage.style.width);
            var x = parseInt(this.lightboxImage.style.left);
        	var centerX =  x / (this.width - imageWidth);
        }
        
        var centreY = 0.5;
        if(!isNaN(this.lightboxImage.style.height))
        {
            var imageHeight = parseInt(this.lightboxImage.style.height);
            var y = parseInt(this.lightboxImage.style.top);
    	    var centerY =  y / (this.height - imageHeight);
        } 

        centerX = Math.round(centerX*10)/10;
        centerY = Math.round(centerY*10)/10;
    	return [centreX, centreY];
    },    
    
    setPosition : function (centerXScale, centerYScale) 
    {
        var imageWidth = parseInt(this.lightboxImage.style.width);
        var imageHeight = parseInt(this.lightboxImage.style.height);
        
    	var newX = (this.width / 2) - (centerXScale * imageWidth);
    	var newY = (this.height / 2) - (centerYScale * imageHeight);

        /*var position = this.getBounds(newX, newY);
        this.lightboxImage.style.left = position[0] + 'px';
        this.lightboxImage.style.top = position[1] + 'px';*/
        
        //this.lightboxImage.style.left = newX + 'px';
        //this.lightboxImage.style.top = newY + 'px';
        
        
    },
    
    getSize : function(width, height, scale)
    {
    	if(scale >= this.scaleNumber)
    		return [width, height];
    		
        // a scale of zero is the image fitted to the view port
        var targetHeight = this.height;
        var targetWidth = this.width; 
        
        var widthScale = targetWidth / width;
        var heightScale = targetHeight / height;
        var scaleFactor = (widthScale > heightScale) ? heightScale : widthScale;
        
	
       	scaleFactor = (((1 - scaleFactor) / this.scaleNumber) * scale) + scaleFactor

    	if(scaleFactor > 1) scaleFactor=1; // when the image is greater that the width of the box.
	
        return [width * scaleFactor, height * scaleFactor];
    },

    renderImage : function(scale) 
    {
        var image = this.imageArray[this.activeImage][2];
    	var centrePosition = (image.src == this.lightboxImage.src && scale != 0)
    		? this.getCurrentCenter()
    		: [0.5, 0.5];
    		
        var oldsize = [parseInt(this.lightboxImage.style.width), parseInt(this.lightboxImage.style.height)];
        var oldpos = [parseInt(this.lightboxImage.style.left), parseInt(this.lightboxImage.style.top)];
        
        var size = this.getSize(image.width, image.height, scale);
        
        this.lightboxImage.style.width = size[0] + "px";
        this.lightboxImage.style.height = size[1] + "px";
        this.lightboxImage.src = this.imageArray[this.activeImage][0];
        
        var newX = (this.width - size[0]) * centrePosition[0];
        var newY = (this.height - size[1]) * centrePosition[1];
        
        this.lightboxImage.style.left = newX + 'px';
        this.lightboxImage.style.top = newY + 'px';
        
        //this.setPosition(centrePosition[0], centrePosition[1]);
    },

    resizeImageContainer: function(imgWidth, imgHeight) {

        // get current width and height
        var widthCurrent  = this.outerImageContainer.getWidth();
        var heightCurrent = this.outerImageContainer.getHeight();

        // get new width and height
        var widthNew  = (imgWidth  + LightboxOptions.borderSize * 2);
        var heightNew = (imgHeight + LightboxOptions.borderSize * 2);

        // scalars based on change from old to new
        var xScale = (widthNew  / widthCurrent)  * 100;
        var yScale = (heightNew / heightCurrent) * 100;

        // calculate size difference between new and old image, and resize if necessary
        var wDiff = widthCurrent - widthNew;
        var hDiff = heightCurrent - heightNew;

        if (hDiff != 0) new Effect.Scale(this.outerImageContainer, yScale, {scaleX: false, duration: this.resizeDuration, queue: 'front'}); 
        if (wDiff != 0) new Effect.Scale(this.outerImageContainer, xScale, {scaleY: false, duration: this.resizeDuration, delay: this.resizeDuration}); 

        // if new and old image are same size and no scaling transition is necessary, 
        // do a quick pause to prevent image flicker.
        var timeout = 0;
        if ((hDiff == 0) && (wDiff == 0)){
            timeout = 100;
            if (Prototype.Browser.IE) timeout = 250;   
        }

        (function(){
            this.prevLink.setStyle({ height: imgHeight + 'px' });
            this.nextLink.setStyle({ height: imgHeight + 'px' });
            this.imageDataContainer.setStyle({ width: widthNew + 'px' });
        }).bind(this).delay(timeout / 1000);
    },
    
    //
    //  showImage()
    //  Display image and begin preloading neighbors.
    //
    showImage: function(){
        this.renderImage(0);

        this.loading.hide();
        new Effect.Appear(this.lightboxImage, { 
            duration: this.resizeDuration, 
            queue: 'end', 
            afterFinish: (function(){ this.updateDetails(); }).bind(this) 
        });
        this.preloadNeighborImages();
    },


    updateDetails: function() {
    
    
        // if caption is not null
        if (this.imageArray[this.activeImage][1] != ""){
            this.caption.update(this.imageArray[this.activeImage][1]).show();
        }
        
        // if image is part of set display 'Image x of x' 
        if (this.imageArray.length > 1){
            this.numberDisplay.update( LightboxOptions.labelImage + ' ' + (this.activeImage + 1) + ' ' + LightboxOptions.labelOf + '  ' + this.imageArray.length).show();
        }

        new Effect.Parallel(
            [ 
                new Effect.SlideDown(this.imageDataContainer, { sync: true, duration: this.resizeDuration, from: 0.0, to: 1 }), 
                new Effect.Appear(this.imageDataContainer, { sync: true, duration: this.resizeDuration }) 
            ], 
            { 
                duration: this.resizeDuration, 
                afterFinish: (function() {
	                // update overlay size and update nav
	                var arrayPageSize = this.getPageSize();
	                this.overlay.setStyle({ height: arrayPageSize[1] + 'px' });
	                this.updateNav();
                }).bind(this)
            } 
        );
        

    },

    updateNav: function() {

        this.hoverNav.show();               

        // if not first image in set, display prev image button
        if (this.activeImage > 0) this.prevLink.show();

        // if not last image in set, display next image button
        if (this.activeImage < (this.imageArray.length - 1)) this.nextLink.show();
        
        if(this.slider == null)
            this.slider = new Control.Slider('zoomHandle', 'zoomSlider', {
                range: $R(1, this.scaleNumber),
                sliderValue: 0,
                onSlide: (function(value) { this.renderImage(value); }).bind(this),
                onChange: function(value) { }
            });
        
        this.enableKeyboardNav();
    },

    enableKeyboardNav: function() {
        document.observe('keydown', this.keyboardAction); 
    },

    disableKeyboardNav: function() {
        document.stopObserving('keydown', this.keyboardAction); 
    },

    keyboardAction: function(event) {
        var keycode = event.keyCode;

        var escapeKey;
        if (event.DOM_VK_ESCAPE) {  // mozilla
            escapeKey = event.DOM_VK_ESCAPE;
        } else { // ie
            escapeKey = 27;
        }

        var key = String.fromCharCode(keycode).toLowerCase();
        
        if (key.match(/x|o|c/) || (keycode == escapeKey)){ // close lightbox
            this.end();
        } else if ((key == 'p') || (keycode == 37)){ // display previous image
            if (this.activeImage != 0){
                this.disableKeyboardNav();
                this.changeImage(this.activeImage - 1);
            }
        } else if ((key == 'n') || (keycode == 39)){ // display next image
            if (this.activeImage != (this.imageArray.length - 1)){
                this.disableKeyboardNav();
                this.changeImage(this.activeImage + 1);
            }
        }
    },

    preloadNeighborImages: function(){
        var preloadNextImage, preloadPrevImage;
        if (this.imageArray.length > this.activeImage + 1){
            preloadNextImage = new Image();
            preloadNextImage.onload = (function(){
                if(this.imageArray.length > this.activeImage + 1)
                    this.imageArray[this.activeImage + 1][2] = preloadNextImage;
            }).bind(this);
            preloadNextImage.src = this.imageArray[this.activeImage + 1][0];
        }
        if (this.activeImage > 0){
            preloadPrevImage = new Image();
            preloadPrevImage.onload = (function(){
                if(this.imageArray.length > this.activeImage + 1)
                    this.imageArray[this.activeImage + 1][2] = preloadPrevImage;
            }).bind(this);
            preloadPrevImage.src = this.imageArray[this.activeImage - 1][0];
        }
    },

    end: function() {
        this.disableKeyboardNav();
        this.lightbox.hide();
        new Effect.Fade(this.overlay, { duration: this.overlayDuration });
        $$('select', 'object', 'embed').each(function(node){ node.style.visibility = 'visible' });
    },
    
    getWindowSize : function()
    {
		var windowWidth, windowHeight;
		
		if (self.innerHeight) {	// all except Explorer
			if(document.documentElement.clientWidth){
				windowWidth = document.documentElement.clientWidth; 
			} else {
				windowWidth = self.innerWidth;
			}
			windowHeight = self.innerHeight;
		} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
			windowWidth = document.documentElement.clientWidth;
			windowHeight = document.documentElement.clientHeight;
		} else if (document.body) { // other Explorers
			windowWidth = document.body.clientWidth;
			windowHeight = document.body.clientHeight;
		}	
		
		return [windowWidth, windowHeight];
    },

    getPageSize: function() {
	        
	     var xScroll, yScroll;
		
		if (window.innerHeight && window.scrollMaxY) {	
			xScroll = window.innerWidth + window.scrollMaxX;
			yScroll = window.innerHeight + window.scrollMaxY;
		} else if (document.body.scrollHeight > document.body.offsetHeight){ // all but Explorer Mac
			xScroll = document.body.scrollWidth;
			yScroll = document.body.scrollHeight;
		} else { // Explorer Mac...would also work in Explorer 6 Strict, Mozilla and Safari
			xScroll = document.body.offsetWidth;
			yScroll = document.body.offsetHeight;
		}
		
		var windowWidth, windowHeight;
		
		if (self.innerHeight) {	// all except Explorer
			if(document.documentElement.clientWidth){
				windowWidth = document.documentElement.clientWidth; 
			} else {
				windowWidth = self.innerWidth;
			}
			windowHeight = self.innerHeight;
		} else if (document.documentElement && document.documentElement.clientHeight) { // Explorer 6 Strict Mode
			windowWidth = document.documentElement.clientWidth;
			windowHeight = document.documentElement.clientHeight;
		} else if (document.body) { // other Explorers
			windowWidth = document.body.clientWidth;
			windowHeight = document.body.clientHeight;
		}	
		
		// for small pages with total height less then height of the viewport
		if(yScroll < windowHeight){
			pageHeight = windowHeight;
		} else { 
			pageHeight = yScroll;
		}
	
		// for small pages with total width less then width of the viewport
		if(xScroll < windowWidth){	
			pageWidth = xScroll;		
		} else {
			pageWidth = windowWidth;
		}

		return [pageWidth,pageHeight];
	}
});