/*
	Table of Contents
	-----------------

	Global Variables

	Extending Built-in Objects	
	- Object.extend(Element)
	- Array.prototype.removeDuplicates()
	- Array.prototype.empty()

	Lightbox Class Declaration
	- initialize()
	- start()
	- changeImage()
	- resizeImageContainer()
	- showImage()
	- updateDetails()
	- updateNav()
	- enableKeyboardNav()
	- disableKeyboardNav()
	- keyboardAction()
	- preloadNeighborImages()
	- end()
	
	Miscellaneous Functions
	- getPageScroll()
	- getPageSize()
	- getKey()
	- listenKey()
	- showSelectBoxes()
	- hideSelectBoxes()
	- pause()
	- initLightbox()
	
	Function Calls
	- addLoadEvent(initLightbox)
	
*/

// *** Global Variables ***

var borderSize = 10; // Rahmenbreite der LightBox (MUSS gleichzeitig mit dem padding in der css-Datei geändert werden!)

var imageArray = new Array;
var activeImage;

if (resizeSpeed > 10)
{ resizeSpeed = 10; }
if (resizeSpeed < 1)
{ resizeSpeed = 1; }

resizeDuration = (11 - resizeSpeed) * 0.15;


// *** Additional Methods

Object.extend
(
 Element, 
 {
  getWidth: function (element) 
  {
   element = $(element);
   return element.offsetWidth; 
  },

  getHeight: function (element) 
  {
   element = $(element);
   return element.offsetHeight; 
  },

  setWidth: function (element, w) 
  {
   element = $(element);
   element.style.width = w + "px";
  },

  setHeight: function (element, h) 
  {
   element = $(element);
   element.style.height = h + "px";
  },

  setTop: function (element, t) 
  {
   element = $(element);
   element.style.top = t +"px";
  },

  setSrc: function (element, src) 
  {
   element = $(element);
   element.src = src; 
  },

  setHref: function (element, href) 
  {
   element = $(element);
   element.href = href; 
  },

  setInnerHTML: function (element, content) 
  {
   element = $(element);
   element.innerHTML = content;
  }
 }
);


// *** Extending built-in Array object ***
// - array.removeDuplicates()
// - array.empty()

Array.prototype.removeDuplicates = function () 
{
 for(i = 1; i < this.length; i++)
 {
  if(this[i][0] == this[i-1][0])
  {
   this.splice(i,1);
  }
 }
}

Array.prototype.empty = function () 
{
 for(i = 0; i <= this.length; i++)
 {
  this.shift();
 }
}


// *** Lightbox Class Declaration ***
// - initialize()
// - start()
// - changeImage()
// - resizeImageContainer()
// - showImage()
// - updateDetails()
// - updateNav()
// - enableKeyboardNav()
// - disableKeyboardNav()
// - keyboardNavAction()
// - preloadNeighborImages()
// - end()

var Lightbox = Class.create ();

Lightbox.prototype = 
{
 // initialize()
 // Constructor runs on completion of the DOM loading. Loops through anchor tags looking for 
 // 'lightbox' references and applies onclick events to appropriate links. The 2nd section of
 // the function inserts html at the bottom of the page which is used to display the shadow 
 // overlay and the image container.
 
 initialize: function () 
 {	
  if (!document.getElementsByTagName)
  {
   return; 
  }

  var anchors = document.getElementsByTagName ('a');

  // loop through all anchor tags
  for (var i = 0; i < anchors.length; i++)
  {
   var anchor = anchors[i];
   var relAttribute = String (anchor.getAttribute ('rel'));
			
   // use the string.match() method to catch 'lightbox' references in the rel attribute
   if (anchor.getAttribute ('href') && (relAttribute.toLowerCase ().match ('lightbox')))
   {
    anchor.onclick = function ()
    {
     myLightbox.start (this); 
     return false;
    }
   }
  }

  // The rest of this code inserts html at the bottom of the page that looks similar to this:
  //
  // <div id="overlay" />
  // <div id="lightbox">
  //  <div id="outerImageContainer">
  //   <div id="imageContainer">
  //    <img id="lightboxImage" />
  //    <div style="" id="hoverNav">
  //     <a href="#" id="prevLink" />
  //     <a href="#" id="nextLink" />
  //    </div>
  //    <div id="loading">
  //     <a href="#" id="loadingLink">
  //      <img src="/lightbox/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">
  //      <div class="fileBottomNavCloseImage" />
  //     </a>
  //    </div>
  //   </div>
  //  </div>
  // </div>

  var objBody = document.getElementsByTagName ("body").item (0);
  
  var objOverlay = document.createElement ("div");
  objOverlay.setAttribute ('id', 'overlay');
  objOverlay.style.display = 'none';
  objOverlay.onclick = function () 
  {
   myLightbox.end (); 
   return false; 
  }
  objBody.appendChild (objOverlay);
		
  var objLightbox = document.createElement ("div");
  objLightbox.setAttribute ('id', 'lightbox');
  objLightbox.style.display = 'none';
  objBody.appendChild (objLightbox);
	
  var objOuterImageContainer = document.createElement ("div");
  objOuterImageContainer.setAttribute ('id', 'outerImageContainer');
  objLightbox.appendChild (objOuterImageContainer);

  var objImageContainer = document.createElement ("div");
  objImageContainer.setAttribute ('id', 'imageContainer');
  objOuterImageContainer.appendChild (objImageContainer);
	
  var objLightboxImage = document.createElement ("img");
  objLightboxImage.setAttribute ('id', 'lightboxImage');
  objImageContainer.appendChild (objLightboxImage);
	
  var objHoverNav = document.createElement ("div");
  objHoverNav.setAttribute ('id', 'hoverNav');
  objImageContainer.appendChild(objHoverNav);
	
  var objPrevLink = document.createElement ("a");
  objPrevLink.setAttribute ('id', 'prevLink');
  objPrevLink.setAttribute ('href', '#');
  objHoverNav.appendChild (objPrevLink);
		
  var objNextLink = document.createElement ("a");
  objNextLink.setAttribute ('id', 'nextLink');
  objNextLink.setAttribute ('href', '#');
  objHoverNav.appendChild (objNextLink);
	
  var objLoading = document.createElement ("div");
  objLoading.setAttribute ('id', 'loading');
  objImageContainer.appendChild (objLoading);
	
  var objLoadingLink = document.createElement ("a");
  objLoadingLink.setAttribute ('id', 'loadingLink');
  objLoadingLink.setAttribute ('href', '#');
  objLoadingLink.onclick = function () 
  {
   myLightbox.end (); 
   return false; 
  }
  objLoading.appendChild (objLoadingLink);
	
  var objLoadingImage = document.createElement ("img");
  objLoadingImage.setAttribute ('src', fileLoadingImage);
  objLoadingLink.appendChild (objLoadingImage);

  var objImageDataContainer = document.createElement ("div");
  objImageDataContainer.setAttribute ('id', 'imageDataContainer');
  objImageDataContainer.className = 'clearfix';
  objLightbox.appendChild (objImageDataContainer);

  var objImageData = document.createElement ("div");
  objImageData.setAttribute ('id', 'imageData');
  objImageDataContainer.appendChild (objImageData);
	
  var objImageDetails = document.createElement ("div");
  objImageDetails.setAttribute ('id', 'imageDetails');
  objImageData.appendChild (objImageDetails);
	
  var objCaption = document.createElement ("span");
  objCaption.setAttribute ('id', 'caption');
  objImageDetails.appendChild (objCaption);
	
  var objNumberDisplay = document.createElement ("span");
  objNumberDisplay.setAttribute ('id', 'numberDisplay');
  objImageDetails.appendChild (objNumberDisplay);
		
  var objBottomNav = document.createElement ("div");
  objBottomNav.setAttribute ('id', 'bottomNav');
  objImageData.appendChild (objBottomNav);
	
  var objBottomNavCloseLink = document.createElement ("a");
  objBottomNavCloseLink.setAttribute ('id', 'bottomNavClose');
  objBottomNavCloseLink.setAttribute ('href','#');
  objBottomNavCloseLink.onclick = function ()
  {
   myLightbox.end (); 
   return false; 
  }
  objBottomNav.appendChild (objBottomNavCloseLink);
	
  var objBottomNavCloseImage = document.createElement ("div");
  objBottomNavCloseImage.setAttribute ('id', 'fileBottomNavCloseImage');
  objBottomNavCloseLink.appendChild (objBottomNavCloseImage);
 },
	
 //
 //	start()
 //	Display overlay and lightbox. If image is part of a set, add siblings to imageArray.
 //
 start: function (imageLink) 
 {	
  hideSelectBoxes ();

  // stretch overlay to fill page and fade in
  var arrayPageSize = getPageSize ();
  Element.setHeight ('overlay', arrayPageSize[1]);
  new Effect.Appear 
  (
   'overlay', 
   {
    duration: 0.2,
    from: 0.0,
    to: 0.8 
   }
  );

  imageArray = [];
  imageNum = 0;		

  if (!document.getElementsByTagName)
  {
   return; 
  }
  var anchors = document.getElementsByTagName ('a');

  // if image is NOT part of a set..
  if((imageLink.getAttribute ('rel') == 'lightbox'))
  {
   // add single image to imageArray
   imageArray.push (new Array (imageLink.getAttribute ('href'), imageLink.getAttribute ('title')));			
  }
  else 
  {
   // if image is part of a set..
   // loop through anchors, find other images in set, and add them to imageArray
   for (var i=0; i<anchors.length; i++)
   {
    var anchor = anchors[i];
    if (anchor.getAttribute ('href') && (anchor.getAttribute ('rel') == imageLink.getAttribute ('rel')))
    {
     imageArray.push (new Array (anchor.getAttribute ('href'), anchor.getAttribute ('title')));
    }
   }
   imageArray.removeDuplicates ();
   while (imageArray[imageNum][0] != imageLink.getAttribute ('href')) 
   {
    imageNum++;
   }
  }

  // calculate top offset for the lightbox and display 
  var arrayPageSize = getPageSize ();
  var arrayPageScroll = getPageScroll ();
  var lightboxTop = arrayPageScroll[1] + (arrayPageSize[3] / 15);

  Element.setTop ('lightbox', lightboxTop);
  Element.show ('lightbox');
		
  this.changeImage (imageNum);
 },

 //
 //	changeImage()
 //	Hide most elements and preload image in preparation for resizing image container.
 //
 changeImage: function (imageNum) 
 {	
  activeImage = imageNum;	// update global var

  // hide elements during transition
  Element.show ('loading');
  Element.hide ('lightboxImage');
  Element.hide ('hoverNav');
  Element.hide ('prevLink');
  Element.hide ('nextLink');
  Element.hide ('imageDataContainer');
  Element.hide ('numberDisplay');		
		
  imgPreloader = new Image ();
		
  // once image is preloaded, resize image container
  imgPreloader.onload = function ()
  {
   Element.setSrc ('lightboxImage', imageArray[activeImage][0]);
   myLightbox.resizeImageContainer (imgPreloader.width, imgPreloader.height);
  }
  imgPreloader.src = imageArray[activeImage][0];
 },

 //
 //	resizeImageContainer()
 //
 resizeImageContainer: function (imgWidth, imgHeight) 
 {
  // get current height and width
  this.wCur = Element.getWidth ('outerImageContainer');
  this.hCur = Element.getHeight ('outerImageContainer');

  // scalars based on change from old to new
  this.xScale = ((imgWidth  + (borderSize * 2)) / this.wCur) * 100;
  this.yScale = ((imgHeight  + (borderSize * 2)) / this.hCur) * 100;

  // calculate size difference between new and old image, and resize if necessary
  wDiff = (this.wCur - borderSize * 2) - imgWidth;
  hDiff = (this.hCur - borderSize * 2) - imgHeight;

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

  // if new and old image are same size and no scaling transition is necessary, 
  // do a quick pause to prevent image flicker.
  if((hDiff == 0) && (wDiff == 0))
  {
   if (navigator.appVersion.indexOf ("MSIE") != -1)
   {
    pause (250); 
   }
   else 
   { 
    pause(100);
   } 
  }

  Element.setHeight ('prevLink', imgHeight);
  Element.setHeight ('nextLink', imgHeight);
  Element.setWidth ('imageDataContainer', imgWidth + (borderSize * 2));

  this.showImage();
 },
	
 //
 //	showImage()
 //	Display image and begin preloading neighbors.
 //
 showImage: function ()
 {
  Element.hide ('loading');
  new Effect.Appear 
  (
   'lightboxImage', 
   {
    duration: 0.5, 
    queue: 'end', 
    afterFinish: function ()
    {
     myLightbox.updateDetails (); 
    } 
   }
  );
  this.preloadNeighborImages ();
 },

 //
 //	updateDetails()
 //	Display caption, image number, and bottom nav.
 //
 updateDetails: function () 
 {
  Element.show ('caption');
  Element.setInnerHTML ( 'caption', imageArray[activeImage][1]);
		
  // if image is part of set display 'Image x of x' 
  if (imageArray.length > 1)
  {
   Element.show ('numberDisplay');
   Element.setInnerHTML ('numberDisplay', translateImage + " " + eval (activeImage + 1) + " " + translateImageOf + " " + imageArray.length);
  }

  new Effect.Parallel
  (
   [
    new Effect.SlideDown
    (
     'imageDataContainer',
     {
      sync: true, 
      duration: resizeDuration + 0.25, 
      from: 0.0, 
      to: 1.0 
     }
    ), 
	new Effect.Appear
	(
	 'imageDataContainer', 
	 {
	  sync: true, 
	  duration: 1.0 
	 }
	)
   ], 
   {
    duration: 0.65, 
    afterFinish: function () 
    {
     myLightbox.updateNav ();
    } 
   } 
  );
 },

 //
 //	updateNav()
 //	Display appropriate previous and next hover navigation.
 //
 updateNav: function () 
 {
  Element.show ('hoverNav');				

  // if not first image in set, display prev image button
  if (activeImage != 0)
  {
   Element.show ('prevLink');
   document.getElementById ('prevLink').onclick = function () 
   {
    myLightbox.changeImage (activeImage - 1); 
    return false;
   }
  }

  // if not last image in set, display next image button
  if(activeImage != (imageArray.length - 1))
  {
   Element.show ('nextLink');
   document.getElementById ('nextLink').onclick = function () 
   {
    myLightbox.changeImage (activeImage + 1); 
    return false;
   }
  }
		
  this.enableKeyboardNav ();
 },

 //
 //	enableKeyboardNav()
 //
 enableKeyboardNav: function () 
 {
  document.onkeydown = this.keyboardAction; 
 },

 //
 //	disableKeyboardNav()
 //
 disableKeyboardNav: function () 
 {
  document.onkeydown = '';
 },

 //
 //	keyboardAction()
 //
 keyboardAction: function (e) 
 {
  if (e == null)   // ie
  { 
   keycode = event.keyCode;
  } 
  else   // mozilla
  { 
   keycode = e.which;
  }

  key = String.fromCharCode (keycode).toLowerCase ();
		
  if ((key == 'x') || (key == 'o') || (key == 'c') || (key == 's'))  // close lightbox
  {	
   myLightbox.end();
  }
  else if ((key == 'p') || (key == 'z') || (key == 'k'))  // display previous image
  {	
   if (activeImage != 0) 
   {
    myLightbox.disableKeyboardNav ();
    myLightbox.changeImage (activeImage - 1);
   }
  }
  else if ((key == 'n') || (key == 'w'))   // display next image
  {	
   if (activeImage != (imageArray.length - 1))
   {
    myLightbox.disableKeyboardNav ();
    myLightbox.changeImage (activeImage + 1);
   }
  }
 },

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

 //
 //	end()
 //
 end: function () 
 {
  this.disableKeyboardNav ();
  Element.hide ('lightbox');
  new Effect.Fade 
  (
   'overlay', 
   {
    duration: 0.2
   }
  );
  showSelectBoxes ();
 }
}

// -----------------------------------------------------------------------------------
//
// getPageScroll()
// Returns array with x,y page scroll values.
// Core code from - quirksmode.org
//
function getPageScroll()
{
 var yScroll;
 if (self.pageYOffset) 
 {
  yScroll = self.pageYOffset;
 }
 else if (document.documentElement && document.documentElement.scrollTop)   // Explorer 6 Strict
 {	 
  yScroll = document.documentElement.scrollTop;
 }
 else if (document.body)   // all other Explorers
 {
  yScroll = document.body.scrollTop;
 }

 arrayPageScroll = new Array ('', yScroll) 
 return arrayPageScroll;
}

// -----------------------------------------------------------------------------------
//
// getPageSize()
// Returns array with page width, height and window width, height
// Core code from - quirksmode.org
// Edit for Firefox by pHaez
//
function getPageSize()
{
 var xScroll, yScroll;
 if (window.innerHeight && window.scrollMaxY) 
 {	
  xScroll = document.body.scrollWidth;
  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 + document.documentElement.scrollTop;
 }
	
 var windowWidth, windowHeight;
 if (self.innerHeight)    // all except Explorer
 {	
  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 = windowWidth;
 } 
 else 
 {
  pageWidth = xScroll;
 }

 arrayPageSize = new Array (pageWidth, pageHeight + 500, windowWidth, windowHeight) 
 return arrayPageSize;
}

// -----------------------------------------------------------------------------------
//
// getKey(key)
// Gets keycode. If 'x' is pressed then it hides the lightbox.
//
function getKey (e)
{
 if (e == null)    // ie
 { 
  keycode = event.keyCode;
 } 
 else    // mozilla
 { 
  keycode = e.which;
 }
 key = String.fromCharCode (keycode).toLowerCase ();
	
 if (key == 'x')
 {
 }
}

// -----------------------------------------------------------------------------------
//
// listenKey()
//
function listenKey () 
{
 document.onkeypress = getKey; 
}
	
// ---------------------------------------------------
function showSelectBoxes ()
{
 selects = document.getElementsByTagName ("select");
 for (i = 0; i != selects.length; i++) 
 {
  selects[i].style.visibility = "visible";
 }
}

// ---------------------------------------------------
function hideSelectBoxes ()
{
 selects = document.getElementsByTagName ("select");
 for (i = 0; i != selects.length; i++) 
 {
  selects[i].style.visibility = "hidden";
 }
}

// ---------------------------------------------------
//
// pause(numberMillis)
// Pauses code execution for specified time. Uses busy code, not good.
// Code from http://www.faqts.com/knowledge_base/view.phtml/aid/1602
//
function pause (numberMillis) 
{
 var now = new Date ();
 var exitTime = now.getTime () + numberMillis;
 while (true) 
 {
  now = new Date ();
  if (now.getTime() > exitTime)
   return;
 }
}

// ---------------------------------------------------
function initLightbox () 
{
 myLightbox = new Lightbox(); 
}

Event.observe (window, 'load', initLightbox, false);