/*
 * jQuery Galleriffic plugin
 *
 * Copyright (c) 2008 Trent Foley (http://trentacular.com)
 * Licensed under the MIT License:
 *   http://www.opensource.org/licenses/mit-license.php
 *
 * Thanks to Taku Sano (Mikage Sawatari), whose history plugin I adapted to work with Galleriffic
 * Modified by Ghismo (ghismo.com) to disable the location rewrite 
 */
;(function($) {

	// Write noscript style
	document.write("<style type='text/css'>.noscript{display:none}</style>");

	var galleryOffset = 0;
	var galleries = [];
	var allImages = [];	

	function getHashFromString(hash) {
		if (!hash) return -1;
		hash = hash.replace(/^.*#/, '');
		if (isNaN(hash)) return -1;
		return (+hash);
	}

	function getHash() {
		var hash = location.hash;
		return getHashFromString(hash);
	}

	function registerGallery(gallery) {
		galleries.push(gallery);
		// update the global offset value
		galleryOffset += gallery.data.length;
	}

	function getGallery(hash) {
		for (i = 0; i < galleries.length; i++) {
			var gallery = galleries[i];
			if (hash < (gallery.data.length+gallery.offset))
				return gallery;
		}
		return 0;
	}
	
	function getIndex(gallery, hash) {
		return hash-gallery.offset;
	}
	
	function clickHandler(e, gallery, link) {

		var hash = getHashFromString(link.href);
		if (hash >= 0) {
			var index = getIndex(gallery, hash);
			if (index >= 0)
				gallery.goto(index);
		}
		e.preventDefault();
	}

	var defaults = {
		numThumbs:              20,
		preloadAhead:           40, // Set to -1 to preload all images
		nextPageLinkText:       'Next &rsaquo;',
		prevPageLinkText:       '&lsaquo; Prev'
	};

	$.fn.galleriffic = function(thumbsContainerSel, settings) {
		//  Extend Gallery Object
		$.extend(this, {
			initializeThumbs: function() {
				this.data = [];
				var gallery = this;
				
				this.$thumbsContainer.find('ul.thumbs > li').each(function(i) {
					var $aThumb = $(this).find('a.thumb');
					var hash = gallery.offset+i;

					gallery.data.push({
						title:$aThumb.attr('title'),
						slideUrl:$aThumb.attr('href'),
						hash:hash
					});
					
				});
				return this;
			},

			isPreloadComplete: false,

			preloadInit: function() {
				if (this.settings.preloadAhead == 0) return this;
				
				this.preloadStartIndex = this.currentIndex;
				var nextIndex = this.getNextIndex(this.preloadStartIndex);
				return this.preloadRecursive(this.preloadStartIndex, nextIndex);
			},
			
			preloadRelocate: function(index) {
				// By changing this startIndex, the current preload script will restart
				this.preloadStartIndex = index;
				return this;
			},

			preloadRecursive: function(startIndex, currentIndex) {
				// Check if startIndex has been relocated
				if (startIndex != this.preloadStartIndex) {
					var nextIndex = this.getNextIndex(this.preloadStartIndex);
					return this.preloadRecursive(this.preloadStartIndex, nextIndex);
				}

				var gallery = this;

				// Now check for preloadAhead count
				var preloadCount = currentIndex - startIndex;
				if (preloadCount < 0)
					preloadCount = this.data.length-1-startIndex+currentIndex;
				if (this.settings.preloadAhead >= 0 && preloadCount > this.settings.preloadAhead) {
					// Do this in order to keep checking for relocated start index
					setTimeout(function() { gallery.preloadRecursive(startIndex, currentIndex); }, 500);
					return this;
				}

				var imageData = this.data[currentIndex];
				if (!imageData)
					return this;

				// If already loaded, continue
				if (imageData.image)
					return this.preloadNext(startIndex, currentIndex); 
				
				// Preload the image
				var image = new Image();
				
				image.onload = function() {
					imageData.image = this;
					gallery.preloadNext(startIndex, currentIndex);
				};

				image.alt = imageData.title;
				image.src = imageData.slideUrl;

				return this;
			},
			
			preloadNext: function(startIndex, currentIndex) {
				var nextIndex = this.getNextIndex(currentIndex);
				if (nextIndex == startIndex) {
					this.isPreloadComplete = true;
				} else {
					// Use set timeout to free up thread
					var gallery = this;
					setTimeout(function() { gallery.preloadRecursive(startIndex, nextIndex); }, 100);
				}
				return this;
			},

			getNextIndex: function(index) {
				var nextIndex = index+1;
				if (nextIndex >= this.data.length)
					nextIndex = 0;
				return nextIndex;
			},
			
			getPrevIndex: function(index) {
				var prevIndex = index-1;
				if (prevIndex < 0)
					prevIndex = this.data.length-1;
				return prevIndex;
			},

			goto: function(index) {
				if (index < 0) index = 0;
				else if (index >= this.data.length) index = this.data.length-1;
				
				
				if (this.settings.onChange)
					this.settings.onChange(this.currentIndex, index);
					
				
				this.currentIndex = index;
				this.preloadRelocate(index);
				return this.refresh();
			},
			
			refresh: function() {
				var imageData = this.data[this.currentIndex];
				if (!imageData)
					return this;
				
				// Flag we are transitioning
				var isTransitioning = true;

				var gallery = this;

				var transitionOutCallback = function() {
					// Flag that the transition has completed
					isTransitioning = false;

					// Update Controls
					if (gallery.$controlsContainer) {
						gallery.$controlsContainer
							.find('div.nav-controls a.prev').attr('href', '#'+gallery.data[gallery.getPrevIndex(gallery.currentIndex)].hash).end()
							.find('div.nav-controls a.next').attr('href', '#'+gallery.data[gallery.getNextIndex(gallery.currentIndex)].hash);
					}

					var imageData = gallery.data[gallery.currentIndex];
			
				}
				// This causes the preloader (if still running) to relocate out from the currentIndex
				this.relocatePreload = true;

				return this.syncThumbs();
			},
			
			syncThumbs: function() {
				if (this.$thumbsContainer) {
					var page = Math.floor(this.currentIndex / this.settings.numThumbs);
					if (page != this.currentPage) {
						this.currentPage = page;
						this.updateThumbs();
					}

/*
					// Remove existing selected class and add selected class to new thumb
					var $thumbs = this.$thumbsContainer.find('ul.thumbs').children();
					$thumbs.filter('.selected').removeClass('selected');
					$thumbs.eq(this.currentIndex).addClass('selected');
					*/
				}

				return this;
			},

			updateThumbs: function() {
				var gallery = this;
				var transitionOutCallback = function() {
					gallery.rebuildThumbs();
					gallery.settings.onPageTransitionIn();
				};

				this.settings.onPageTransitionOut(transitionOutCallback);
				return this;
			},

			rebuildThumbs: function() {
				// Initialize currentPage to first page
				if (this.currentPage < 0)
					this.currentPage = 0;
				
				var needsPagination = this.data.length > this.settings.numThumbs;

				// Rebuild bottom pager
				if (needsPagination) {
					var $bottomPager = this.$thumbsContainer.find('div.bottom');
					if ($bottomPager.length == 0)
						$bottomPager = this.$thumbsContainer.append('<div class="bottom pagination"></div>').find('div.bottom');
					else
						$bottomPager.empty();

					this.buildPager($bottomPager);
				}

				var startIndex = this.currentPage*this.settings.numThumbs;
				var stopIndex = startIndex+this.settings.numThumbs-1;
				if (stopIndex >= this.data.length)
					stopIndex = this.data.length-1;

				// Show/Hide thumbs
				var $thumbsUl = this.$thumbsContainer.find('ul.thumbs');
				$thumbsUl.find('li').each(function(i) {
					var $li = $(this);
					if (i >= startIndex && i <= stopIndex) {
						$li.show();
					} else {
						$li.hide();
					}
				});

				// Remove the noscript class from the thumbs container ul
				$thumbsUl.removeClass('noscript');
				
				return this;
			},

			buildPager: function(pager) {
				var gallery = this;
				var startIndex = this.currentPage*this.settings.numThumbs;
				
				// Prev Page Link
				if (this.currentPage > 0) {
					var prevPage = startIndex - this.settings.numThumbs;
					pager.append('<a class="thumb_left" rel="history" href="#'+this.data[prevPage].hash+'" title="'+this.settings.prevPageLinkText+'"></a>');
					
				}
				// Next Page Link
				var nextPage = startIndex+this.settings.numThumbs;
				if (nextPage < this.data.length) {
					pager.append('<a class="thumb_right" rel="history" href="#'+this.data[nextPage].hash+'" title="'+this.settings.nextPageLinkText+'"></a>');
				}

				pager.find('a').click(function(e) {
					clickHandler(e, gallery, this);
				});

				return this;
			}
		});

		// Now initialize the gallery
		this.settings = $.extend({}, defaults, settings);

		// Set the hash index offset for this gallery
		this.offset = galleryOffset;

		this.$thumbsContainer = $(thumbsContainerSel);
		this.initializeThumbs();

		// Add this gallery to the global galleries array
		registerGallery(this);

		this.numPages = Math.ceil(this.data.length/this.settings.numThumbs);
		this.currentPage = -1;
		this.currentIndex = 0;
		var gallery = this;
	
		// Build image
		var hash = getHash();
		var hashGallery = (hash >= 0) ? getGallery(hash) : 0;
		var gotoIndex = (hashGallery && this == hashGallery) ? (hash-this.offset) : 0;
		this.goto(gotoIndex);

		return this;
	};
})(jQuery);