// code from http://jqueryfordesigners.com/jquery-infinite-carousel/
// modified by gjg 2009-10-24
// adding automatic cycling, removing requirement for control buttons
(function($) { // Compliant with jquery.noConflict()
$.fn.infiniteCarousel = function (o) {
	o = $.extend({
        createButtons: false,
        effectDuration: 800
    }, o || {});

    function repeat(str, num) {
        var out = '';
        for (var i=0;i<num;i++) {
        	out = out + str;
        }
        return out;
        // return new Array( num + 1 ).join( str );
    }
  
    return this.each(function () {
        var $wrapper = $('> div', this).eq(0).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
            }, o.effectDuration, 'swing', 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;
        }
        
        // create a public interface to move to a specific page
        $(this).bind('goto', function (event, page) {
            gotoPage(page);
        });
		$(this).bind('goforward', function (event) {
			gotoPage(currentPage + 1);
		});
		$(this).bind('goback', function (event) {
			gotoPage(currentPage - 1);
		});

        if (o.createButtons) {
			$wrapper.after('<a class="arrow back">&lt;</a><a class="arrow forward">&gt;</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);
			});
		}
		
    });  
};
})(jQuery);