$(document).ready(function() {

/* ---------- Functions ---------- */

    /**
     * Event handler for previous/next buttons. Displays the
     * previous or next carousel item.
     *
     * @param   object  carousel        The carousel container.
     * @author  Dianne Castillo
     *
     */
    var cycleCarousel = function(ev) {

        var carouselNavButton = $(this);
        var carouselNavButtonClass = $(this).attr('class');

        var carouselItemList = ev.data.itemList;
        var currentCarouselItem = ev.data.currentItem;
        var carouselItemCount = ev.data.itemList.length;
        var carouselItemLast = carouselItemCount - 1;
        var newCarouselItemIndex;
        var newCarouselItem;

        // Couldn't get an item count
        if(typeof(carouselItemCount) == 'undefined' || carouselItemCount === null || carouselItemCount === 0) {
            return;
        }

        // Hide all
        $(carouselItemList).each(function(i, el) {
            $(el).hide();
        }); // END: loop through all Carousel Items

        // Select previous item
        if ($(carouselNavButton).hasClass('previous')) {
            newCarouselItemIndex = currentCarouselItem - 1;
            // Go to last item if at the beginning
            newCarouselItemIndex = newCarouselItemIndex < 0 ? carouselItemLast : newCarouselItemIndex;
        }
        // Select next item
        else if ($(carouselNavButton).hasClass('next')) {
            newCarouselItemIndex = currentCarouselItem + 1;
            // Go to first item if at the end
            newCarouselItemIndex = newCarouselItemIndex > carouselItemLast ? 0 : newCarouselItemIndex;
        }

        // Show new item
        var newCarouselItem = $(carouselItemList)[newCarouselItemIndex];
        $(newCarouselItem).show();
        // Store new item
        ev.data.currentItem = newCarouselItemIndex;

    }; // END: cycleCarousel

    /**
     * Initiate News and Events carousel on Home Page.
     *
     * @author  Dianne Castillo
     *
     */
    var initHomeCarousel = function() {

        var carouselItemList = '#carousel .news-item-container';
        var carouselItemCount = $(carouselItemList).length;

        var carousel = {
            'itemList': $(carouselItemList),
            'currentItem': 0
         };

        // Add previous/next buttons
        var newsLink = '.more-news a';
        $(newsLink).before('<button class="previous"><img src="http://www.whitlam.org/__data/assets/image/0018/105507/btn-home-carousel-previous.gif" width="19" height="19" alt="Previous" title="Previous" /></button>');
        $(newsLink).after('<button class="next"><img src="http://www.whitlam.org/__data/assets/image/0017/105506/btn-home-carousel-next.gif" width="19" height="19" alt="Next" title="Next" /></button>');
        var buttonPrevious = '.more-news button.previous';
        var buttonNext = '.more-news button.next';

        // Add event handlers for previous/next buttons
        $(buttonPrevious).bind('click', carousel, cycleCarousel);
        $(buttonNext).bind('click', carousel, cycleCarousel);

    }; // END: initHomeCarousel

/* ---------- Events ----------- */

    initHomeCarousel();

});