/**
 * @author Stéphane Roucheray 
 * @extends jquery
 */



	$.fn.infiniteCarousel = function () {

		function repeat(str, num) {
			return new Array( num + 1 ).join( str );
		}
	  
		return this.each(function () {
			var $wrapper = $('> div', this).css('overflow', 'hidden'),
				$slider = $wrapper.find('> ul'),
				$items = $slider.find('> li'),
				$single = $items.filter(':first'),
				
				singleWidth = $single.outerWidth(), 
				visible = Math.ceil($wrapper.innerWidth() / singleWidth), // note: doesn't include padding or border
				currentPage = 1,
				pages = Math.ceil($items.length / visible);            


			// 1. Pad so that 'visible' number will always be seen, otherwise create empty items
			if (($items.length % visible) != 0) {
				$slider.append(repeat('<li class="empty" />', visible - ($items.length % visible)));
				$items = $slider.find('> li');
			}

			// 2. Top and tail the list with 'visible' number of items, top has the last section, and tail has the first
			$items.filter(':first').before($items.slice(- visible).clone().addClass('cloned'));
			$items.filter(':last').after($items.slice(0, visible).clone().addClass('cloned'));
			$items = $slider.find('> li'); // reselect
			
			// 3. Set the left position to the first 'real' item
			$wrapper.scrollLeft(singleWidth * visible);
			
			// 4. paging function
			function gotoPage(page) {
				var dir = page < currentPage ? -1 : 1,
					n = Math.abs(currentPage - page),
					left = singleWidth * dir * visible * n;
				
				$wrapper.filter(':not(:animated)').animate({
					scrollLeft : '+=' + left
				}, 500, function () {
					if (page == 0) {
						$wrapper.scrollLeft(singleWidth * visible * pages);
						page = pages;
					} else if (page > pages) {
						$wrapper.scrollLeft(singleWidth * visible);
						// reset back to start position
						page = 1;
					} 

					currentPage = page;
				});                
				
				return false;
			}
			
			$wrapper.after('<a class="arrow back"></a><a class="arrow forward"></a>');
			
			// 5. Bind to the forward and back buttons
			$('a.back', this).click(function () {
				return gotoPage(currentPage - 1);                
			});
			
			$('a.forward', this).click(function () {
				return gotoPage(currentPage + 1);
			});
			
			// create a public interface to move to a specific page
			$(this).bind('goto', function (event, page) {
				gotoPage(page);
			});
		});  
	};

	$(document).ready(function () {
	  $('.infiniteCarousel').infiniteCarousel();
	});