// JavaScript Document

$.fn.infiniteCarousel = function (options) {

	options = $.extend($.fn.infiniteCarousel.defaults, options);

	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),
			currentPage = 1,
			pages = Math.ceil($items.length / visible),
			autoAdvance = null;            
			
	
		// 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;
				} 
				
				$('a:nth-child(' + currentPage + ')', pagination).removeClass('active');
				$('a', pagination).removeClass('adjacent')
				$('a:nth-child(' + page + ')', pagination).addClass('active').prev().addClass('adjacent');
				currentPage = page;
			});                
			
			return false;
		}
		
		var pagination = $('<div class="pagination"></div>').insertBefore($wrapper);
		for (var i = 1; i <= pages; i++) {
			$('<a class="link-' + i + '" href="#">' + i + '</a>').click(function() {
				gotoPage(parseInt($(this).html()));
				return false;
			}).appendTo(pagination);
		}
		$('a:first', pagination).addClass('active');
		
		$wrapper.after('<a class="arrow back">Back;</a><a class="arrow forward">Next</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);
		});
		
		
		// Initiate auto advance
		
		function initAutoAdvance () {
			return setInterval (function () {
				gotoPage(currentPage + 1);
			}, options.speed);
		};
		
		if (options.speed > 0) {
			autoAdvance = initAutoAdvance ();
			$wrapper.hover(function () {
					clearInterval(autoAdvance);
				}, function () {
					autoAdvance = initAutoAdvance ();
			});
		};
		
	});  
};

$.fn.infiniteCarousel.defaults = {
	speed : 5000
};