/*!
* jQuery Carousel plugin v0.3.7
* Yet another jQuery carousel.
* http://ajk.im/js/jquery.carousel.js
*
* Copyright 2011 Antti-Jussi Kovalainen
*
* Usage: $('ul.someElement').carousel({ options here });
*
* Options:
*     transition: '[scroll|fade]'
*     slideshow: seconds (0 to disable)
*     showArrows: true|false
*     showNavigation: true|false (instant navigation to slides, numbers)
*     fluid: true|false
*/

(function ($) {

    $.fn.carousel = function (opts) {

        var options = {
            transition: 'scroll', // 'scroll' or 'fade'
            slideshow: 0, // time in seconds, 0 to disable

            showArrows: true,
            showNavigation: false,

            fluid: true, // fluid layout (= monitor resizing)

            firstItem: 1 // NOT fully implemented yet, TODO:
        };
        jQuery.extend(options, opts);

        return this.each(function () {

            // TODO: check if $(this) is a wrapper <div> and don't create a wrapper the

            var $this = $(this),
                list = $this,
                wrapper = $('<div class="carouselWrapper"></div>'),
                items = list.find('> li'),

                currentPage = 1,
                singleWidth = 0, // used only by scrolling
                itemsPerPage = 1,
                pages = 1,

                slideshowTimer = null,
                paused = false,

                setCSS = null;

            function init() {
                // create a wrapper <div>
                wrapper.insertBefore(list)
                       .append(list);

                items = list.find('> li');

                // add 'hover' class on hover
                list.hover(function () {
                    list.addClass('hover');
                }, function () {
                    list.removeClass('hover');
                });

                // transition specific initialization
                if (options.transition == 'scroll') {
                    initScroll();
                    setCSS = setScrollCSS;
                }
                else if (options.transition == 'fade') {
                    initFade();
                    setCSS = setFadeCSS;
                }
                else {
                    alert('Unknown jQuery carousel transition!');
                    return;
                }

                setCSS();

                // add optional navigation/arrows
                if (options.showArrows) {
                    addArrowNav();
                }

                if (options.showNavigation) {
                    addJumpNav();
                }

                if (options.fluid) {
                    $(window).resize(function (e) {
                        setCSS();
                    });

                    // wait for images to load and then re-set  CSS
                    var currentItem = $(items[currentPage - 1]),
                        images = currentItem.find('img'),
                        tmpCount = 0;

                    images.load(function () {
                        tmpCount++;

                        if (tmpCount == images.length) {
                            setCSS();
                        }

                        $(this).unbind('load');
                    });
                }

                // start slideshow
                if (isSlideshow()) {
                    setSlideshow();
                }

                // bind to an event (support external events)
                list.bind('goto', function (event, page) {
                    gotoPage(page);
                });

                list.bind('pause', function () {
                    paused = true;
                });

                list.bind('play', function () {
                    paused = false;
                });
            }

            function initScroll() {
                var firstItem = $(items[0]);

                items.css({
                    display: 'inline-block',
                    float: 'left'
                });

                singleWidth = firstItem.outerWidth(true);

                if (singleWidth == 0) {
                    // TODO: replace this quick fix (crashes if singleWidth == 0)
                    return;
                }

                // TODO: check that all items are equal width -- it's a requirement with this type of scrolling

                itemsPerPage = Math.floor(wrapper.outerWidth(true) / singleWidth);
                pages = countPages();

                // add empty items to end of list, when there are not enough
                if ((items.length % itemsPerPage) != 0) {
                    var emptyItemCount = itemsPerPage - (items.length % itemsPerPage),
                        emptyItem = firstItem.clone().empty().addClass('empty');

                    emptyItem.height(firstItem.height());
                    emptyItem.width(firstItem.width());

                    for (var i = 0; i < emptyItemCount; i++) {
                        list.append(emptyItem.clone());
                    }
                }
                items = list.find('> li');

                // clone items to the start and end of the list to enable "infinite" scrolling
                if (pages > 1) {
                    firstItem.before(items.slice(-itemsPerPage).clone().addClass('cloned'));
                    items.filter(':last').after(items.slice(0, itemsPerPage).clone().addClass('cloned'));

                    // position to first real item
                    list.css('left', -singleWidth * itemsPerPage);
                }

                items = list.find('> li');
            }

            function initFade() {
                itemsPerPage = 1;
                pages = countPages();
            }


            function setScrollCSS() {
                var currentItem = $(items[currentPage - 1]);

                // create a wrapper <div>
                wrapper.css({
                    height: '100%',
                    overflow: 'hidden',
                    position: 'relative',
                    width: list.width()
                });

                // set css
                list.css({
                    listStyle: 'none',
                    position: 'absolute',
                    width: '31000em'
                });

                items.css({
                    display: 'block',
                    float: 'left'
                });
            }


            function setFadeCSS() {
                // reset in-line styles
                wrapper.attr('style', '');
                list.attr('style', '');
                items.attr('style', '');

                var currentItem = $(items[currentPage - 1]);

                width = currentItem.outerWidth();

                wrapper.css({
                    height: currentItem.outerHeight(),
                    overflow: 'hidden',
                    position: 'relative'
                });

                list.css({
                    listStyle: 'none',
                    position: 'absolute',
                    width: '31000em'
                });

                items.css({
                    display: 'none',
                    position: 'absolute',
                    top: 0,
                    left: 0,
                    width: width
                });

                currentItem.show();
            }


            function countPages() {
                return new Number(Math.ceil(items.length / itemsPerPage)); // TODO: include border and/or padding
            }


            function addArrowNav() {

                var backArrow = $('<a href="#" class="nav carouselBack">&larr;</a>'),
                    nextArrow = $('<a href="#" class="nav carouselNext">&rarr;</a>');

                if (pages <= 1) {
                    backArrow = $('<span href="#" class="nav carouselBack disabled">&larr;</span>');
                    nextArrow = $('<span href="#" class="nav carouselNext disabled">&rarr;</span>');
                }
                else {
                    backArrow.click(function () {
                        return gotoPage(currentPage - 1);
                    });

                    nextArrow.click(function () {
                        return gotoPage(currentPage + 1);
                    });
                }

                wrapper.after(nextArrow).after(backArrow);
            }

            function addJumpNav() {
                if (pages <= 1) {
                    return;
                }

                var nav = $('<div class="carouselNav"></div>');

                for (var i = 1; i <= pages; ++i) {
                    var item = $('<a href="#">' + i + '</a>');

                    if (i == 1) {
                        item.addClass('act');
                    }

                    item.click(function () {
                        var j = $(this).index();
                        return gotoPage(j + 1);
                    });
                    nav.append(item);
                }

                wrapper.after(nav);
            }


            function isSlideshow() {
                return (!isNaN(options.slideshow) && (options.slideshow > 0));
            }

            function setSlideshow() {
                clearTimeout(slideshowTimer);
                slideshowTimer = setTimeout(function () {
                    gotoPage(currentPage + 1, true);
                }, options.slideshow * 1000);
            }

            function gotoPage(page, calledBySlideshow) {
                if (currentPage == page || pages == 1) {
                    return false;
                }

                // start the slideshow-timer again
                if (isSlideshow()) {
                    if (page > pages) {
                        page = 1;
                    }
                    setSlideshow();
                }

                if (calledBySlideshow && (list.hasClass('hover') || paused)) {
                    return false;
                }

                if (options.showNavigation) {
                    var navItems = wrapper.siblings('.carouselNav').children();
                    navItems.removeClass('act');
                    $(navItems[page - 1]).addClass('act');
                }

                if (options.transition == 'scroll') {
                    scrollTo(page);
                }
                else if (options.transition == 'fade') {
                    fadeTo(page);
                }

                if (options.fluid) {
                    setCSS();
                }

                return false;
            }

            function scrollTo(page) {
                if (list.is(':animated')) {
                    return;
                }

                var dir = currentPage > page ? -1 : 1;
                left = singleWidth * itemsPerPage * page,
                    singlePageWidth = singleWidth * itemsPerPage,
                    maxLeft = singleWidth * itemsPerPage * pages,
                    minLeft = singlePageWidth;

                list.animate({
                    left: -left
                }, 500, function () {
                    if (page == 0) {
                        list.css('left', -maxLeft);
                        page = pages
                    }
                    else if (page > pages) {
                        list.css('left', -singlePageWidth);
                        page = 1;
                    }

                    currentPage = page;
                });
            }

            function fadeTo(page) {
                if (page == 0) {
                    page = pages;
                }
                else if (page > pages) {
                    page = 1;
                }

                var currentItem = $(items.get(currentPage - 1)),
                    nextItem = $(items.get(page - 1));

                currentItem.stop(true, true).fadeOut();
                nextItem.stop(true, true).fadeIn();

                currentPage = page;
            }


            init();

        });
    }
})(jQuery);