//
//  Configurationl
//
LightboxOptions = Object.extend({
    fileLoadingImage: 'images/lightbox/loading.gif',
    fileBottomNavCloseImage: 'images/lightbox/closelabel.gif',

    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 Lightbox = Class.create();

Lightbox.prototype = {
    imageArray: [],
    activeImage: 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 () {

        this.updateImageList();

        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) * 0.15) : 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('img', {
            id: 'lightboxImage'
        }), Builder.node('div', {
            id: 'hoverNav'
        }, [
        Builder.node('a', {
            id: 'prevLink',
            href: '#'
        }), Builder.node('a', {
            id: 'nextLink',
            href: '#'
        })]), Builder.node('div', {
            id: 'loading'
        }, Builder.node('a', {
            id: 'loadingLink',
            href: '#'
        }, 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: '#'
        }, Builder.node('img', {
            src: LightboxOptions.fileBottomNavCloseImage
        })))]))]));


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

        var th = this;
        (function () {
            var ids = 'overlay lightbox outerImageContainer imageContainer lightboxImage hoverNav prevLink nextLink loading loadingLink ' + 'imageDataContainer imageData imageDetails caption numberDisplay bottomNav bottomNavClose';
            $w(ids).each(function (id) {
                th[id] = $(id);
            });
        }).defer();
    },

    //
    // updateImageList()
    // Loops through anchor tags looking for 'lightbox' references and applies onclick
    // events to appropriate links. You can rerun after dynamically adding images w/ajax.
    //
    updateImageList: function () {
        this.updateImageList = Prototype.emptyFunction;

        document.observe('click', (function (event) {
            var target = event.findElement('a[rel^=lightbox]') || event.findElement('area[rel^=lightbox]');
            if (target) {
                event.stop();
                this.start(target);
            }
        }).bind(this));
    },

    //
    //  start()
    //  Display overlay and lightbox. If image is part of a set, add siblings to imageArray.
    //
    start: function (imageLink) {

        $$('select', 'object', 'embed').each(function (node) {
            node.style.visibility = 'hidden'
        });

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

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

        this.imageArray = [];
        var imageNum = 0;

        if ((imageLink.rel == 'lightbox')) {
            // if image is NOT part of a set, add single image to imageArray
            this.imageArray.push([imageLink.href, imageLink.title]);
        } else {
            // if image is part of a set..
            this.imageArray =
            $$(imageLink.tagName + '[href][rel="' + imageLink.rel + '"]').
            collect(function (anchor) {
                return [anchor.href, anchor.title];
            }).
            uniq();

            while (this.imageArray[imageNum][0] != imageLink.href) {
                imageNum++;
            }
        }

        // 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.changeImage(imageNum);
    },

    //
    //  changeImage()
    //  Hide most elements and preload image in preparation for resizing image container.
    //
    changeImage: function (imageNum) {

        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];
            this.resizeImageContainer(imgPreloader.width, imgPreloader.height);
        }).bind(this);
        imgPreloader.src = this.imageArray[this.activeImage][0];
    },

    //
    //  resizeImageContainer()
    //
    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'
            });

            this.showImage();
        }).bind(this).delay(timeout / 1000);
    },

    //
    //  showImage()
    //  Display image and begin preloading neighbors.
    //
    showImage: function () {
        this.loading.hide();
        new Effect.Appear(this.lightboxImage, {
            duration: this.resizeDuration,
            queue: 'end',
            afterFinish: (function () {
                this.updateDetails();
            }).bind(this)
        });
        this.preloadNeighborImages();
    },

    //
    //  updateDetails()
    //  Display caption, image number, and bottom nav.
    //
    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: 1.0
        }), 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()
    //  Display appropriate previous and next hover navigation.
    //
    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();

        this.enableKeyboardNav();
    },

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

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

    //
    //  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()
    //  Preload previous and next images.
    //
    preloadNeighborImages: function () {
        var preloadNextImage, preloadPrevImage;
        if (this.imageArray.length > this.activeImage + 1) {
            preloadNextImage = new Image();
            preloadNextImage.src = this.imageArray[this.activeImage + 1][0];
        }
        if (this.activeImage > 0) {
            preloadPrevImage = new Image();
            preloadPrevImage.src = this.imageArray[this.activeImage - 1][0];
        }

    },

    //
    //  end()
    //
    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'
        });
    },

    //
    //  getPageSize()
    //
    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];
    }
}

document.observe('dom:loaded', function () {
    new Lightbox();
});