// -----------------------------------------------------------------------------------
//
//	Lightbox v2.04
//	by Lokesh Dhakar - http://www.lokeshdhakar.com
//	Last Modification: 2/9/08
//
//	For more information, visit:
//	http://lokeshdhakar.com/projects/lightbox2/
//
//	Licensed under the Creative Commons Attribution 2.5 License - http://creativecommons.org/licenses/by/2.5/
//  	- Free for use in both personal and commercial projects
//		- Attribution requires leaving author name, author link, and the license info intact.
//	
//  Thanks: Scott Upton(uptonic.com), Peter-Paul Koch(quirksmode.com), and Thomas Fuchs(mir.aculo.us) for ideas, libs, and snippets.
//  		Artemy Tregubenko (arty.name) for cleanup and help in updating to latest ver of proto-aculous.
//
// -----------------------------------------------------------------------------------
/*

Table of Contents
-----------------
Configuration

Lightbox Class Declaration
- initialize()
- updateImageList()
- start()
- changeImage()
- resizeImageContainer()
- showImage()
- updateDetails()
- updateNav()
- enableKeyboardNav()
- disableKeyboardNav()
- keyboardAction()
- preloadNeighborImages()
- end()
    
Function Calls
- document.observe()
   
*/
// -----------------------------------------------------------------------------------

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


    // Code inserts html at the bottom of the page that looks similar to this:
    //
    //  <div id="overlay"></div>
    //  <div id="lightbox">
    //      <div id="outerImageContainer">
    //          <div id="imageContainer">
    //              <img id="lightboxImage">
    //              <div style="" id="hoverNav">
    //                  <a href="#" id="prevLink"></a>
    //                  <a href="#" id="nextLink"></a>
    //              </div>
    //              <div id="loading">
    //                  <a href="#" id="loadingLink">
    //                      <img src="images/loading.gif">
    //                  </a>
    //              </div>
    //          </div>
    //      </div>
    //      <div id="imageDataContainer">
    //          <div id="imageData">
    //              <div id="imageDetails">
    //                  <span id="caption"></span>
    //                  <span id="numberDisplay"></span>
    //              </div>
    //              <div id="bottomNav">
    //                  <a href="#" id="bottomNavClose">
    //                      <img src="images/close.gif">
    //                  </a>
    //              </div>
    //          </div>
    //      </div>
    //  </div>


    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(); });