(function ($) {
    /*******************************************************************************************/
    // jquery.pajinate.js - version 0.4 FORK 0.2
    // A jQuery plugin for paginating through any number of DOM elements
    //
    // Copyright (c) 2010, Wes Nolte (http://wesnolte.com)
    // Liscensed under the MIT License (MIT-LICENSE.txt)
    // http://www.opensource.org/licenses/mit-license.php
    // Created: 2010-04-16 | Updated: 2011-09-13
    /*******************************************************************************************/

    $.fn.pajinate = function (options) {

        // Setup default option values
        var defaults = {
            item_container_id: '.content',
            items_per_page: 10,
            nav_panel_id: '.page_navigation',
            num_page_links_to_display: 20,
            start_page: 0,
            wrap_around: false,
            nav_label_first: 'First',
            nav_label_prev: 'Prev',
            nav_label_next: 'Next',
            nav_label_last: 'Last',
            show_first_last: true,
            show_prev_next: true
        };
        var options = $.extend(defaults, options);


        return this.each(function () {
            // Set some state information
            var current_page = 'current_page';
            var items_per_page = 'items_per_page';
            var meta;
            var $item_container;
            var $page_container;
            var $items;
            var $nav_panels;
            var total_page_no_links;
            var num_page_links_to_display = options.num_page_links_to_display;

            $page_container = $(this);
            $item_container = $(this).find(options.item_container_id);
            $items = $page_container.find(options.item_container_id).children();
            meta = $page_container;

            // Initialise meta data
            meta.data(current_page, 0);
            meta.data(items_per_page, options.items_per_page);

            // Get the total number of items
            var total_items = $item_container.children().size();

            // Calculate the number of pages needed
            var number_of_pages = Math.ceil(total_items / options.items_per_page);

            // Construct the nav bar
            var more = '<span class="ellipse more">+</span>';
            var less = '<span class="ellipse less">-</span>';

            var first = !options.show_first_last ? '' : '<a class="first_link" href="">' + options.nav_label_first + '</a>';
            var last = !options.show_first_last ? '' : '<a class="last_link" href="">' + options.nav_label_last + '</a>';

            var prev = !options.show_prev_next ? '' : '<a class="previous_link" href="">' + options.nav_label_prev + '</a>';
            var next = !options.show_prev_next ? '' : '<a class="next_link" href="">' + options.nav_label_next + '</a>';

            var navigation_html = first;
            navigation_html += prev + less;
            var current_link = 0;

            while (number_of_pages > current_link) {
                navigation_html += '<a class="page_link" href="" longdesc="' + current_link + '">' + (current_link + 1) + '</a>';
                current_link++;
            }
            navigation_html += more + next;
            navigation_html += last;

            // And add it to the appropriate area of the DOM
            $nav_panels = $page_container.find(options.nav_panel_id);

            if (number_of_pages > 1) {
                if(!$('.page_navigation').hasClass('pagination')) {
                    $('.page_navigation').addClass('pagination');    
                }
                
                $nav_panels.html(navigation_html).each(function () {
                    $(this).find('.page_link:first').addClass('first');
                    $(this).find('.page_link:last').addClass('last');

                });
            }
            else {
                $('.page_navigation').removeClass('pagination');
            }

            // Hide the more/less indicators
            $nav_panels.children('.ellipse').hide();

            // Set the active page link styling
            $nav_panels.find('.previous_link').next().next().addClass('active_page');

            /* Setup Page Display */
            // And hide all pages
            $items.hide();
            // Show the first page
            $items.slice(0, meta.data(items_per_page)).show();

            /* Setup Nav Menu Display */
            // Page number slices

            total_page_no_links = $page_container.children(options.nav_panel_id).children('.page_link').size();
            num_page_links_to_display = Math.min(num_page_links_to_display, total_page_no_links);

            $nav_panels.children('.page_link').hide(); // Hide all the page links
            // And only show the number we should be seeing
            $nav_panels.each(function () {
                $(this).children('.page_link').slice(0, num_page_links_to_display).show();
            });

            /* Bind the actions to their respective links */

            // Event handler for 'First' link
            $page_container.find('.first_link', $page_container).click(function (e) {
                e.preventDefault();

                movePageNumbersRight($(this), 0);
                viewPage(0);
            });

            // Event handler for 'Last' link
            $page_container.find('.last_link', $page_container).click(function (e) {
                e.preventDefault();
                var lastPage = total_page_no_links - 1;
                movePageNumbersLeft($(this), lastPage);
                viewPage(lastPage);
            });

            // Event handler for 'Prev' link
            $page_container.find('.previous_link', $page_container).click(function (e) {
                e.preventDefault();
                showPrevPage($(this));
            });


            // Event handler for 'Next' link
            $page_container.find('.next_link', $page_container).click(function (e) {
                e.preventDefault();
                showNextPage($(this));
            });

            // Event handler for each 'Page' link
            $page_container.find('.page_link', $page_container).click(function (e) {
                e.preventDefault();
                viewPage($(this).attr('longdesc'));
            });

            // Goto the required page
            viewPage(parseInt(options.start_page));
            toggleMoreLess();
            if (!options.wrap_around)
                tagNextPrev();


            function showPrevPage(e) {
                new_page = parseInt(meta.data(current_page)) - 1;

                // Check that we aren't on a boundary link
                if ($(e).siblings('.active_page').prev('.page_link').length == true) {
                    movePageNumbersRight(e, new_page);
                    viewPage(new_page);
                } else if (options.wrap_around) {
                    viewPage(total_page_no_links - 1);
                }

            };

            function showNextPage(e) {
                new_page = parseInt(meta.data(current_page)) + 1;

                // Check that we aren't on a boundary link
                if ($(e).siblings('.active_page').next('.page_link').length == true) {
                    movePageNumbersLeft(e, new_page);
                    viewPage(new_page);
                } else if (options.wrap_around) {
                    viewPage(0);
                }

            };

            function viewPage(page_num) {

                var ipp = meta.data(items_per_page);

                var isLastPage = false;

                // Find the start of the next slice
                start_from = page_num * ipp;

                // Find the end of the next slice
                end_on = start_from + ipp;
                // Hide the current page
                $items.hide()
     .slice(start_from, end_on)
     .show();

                // Reassign the active class
                $page_container.find(options.nav_panel_id).children('.page_link[longdesc=' + page_num + ']').addClass('active_page')
     .siblings('.active_page')
     .removeClass('active_page');

                // Set the current page meta data
                meta.data(current_page, page_num);

                // Hide the more and/or less indicators
                toggleMoreLess();

                // Add a class to the next or prev links if there are no more pages next or previous to the active page
                tagNextPrev();
            };

            // Methods to shift the diplayed index of page numbers to the left or right
            function movePageNumbersLeft(e, new_p) {
                var new_page = new_p;

                var $current_active_link = $(e).siblings('.active_page');

                if ($current_active_link.siblings('.page_link[longdesc=' + new_page + ']').css('display') == 'none') {

                    $nav_panels.each(function () {
                        $(this).children('.page_link')
     .hide() // Hide all the page links
     .slice(parseInt(new_page - num_page_links_to_display + 1), new_page + 1)
     .show();
                    });
                }

            }

            function movePageNumbersRight(e, new_p) {
                var new_page = new_p;

                var $current_active_link = $(e).siblings('.active_page');

                if ($current_active_link.siblings('.page_link[longdesc=' + new_page + ']').css('display') == 'none') {

                    $nav_panels.each(function () {
                        $(this).children('.page_link')
     .hide() // Hide all the page links
     .slice(new_page, new_page + parseInt(num_page_links_to_display))
     .show();
                    });
                }
            }

            // Show or remove the ellipses that indicate that more page numbers exist in the page index than are currently shown
            function toggleMoreLess() {

                if (!$nav_panels.children('.page_link:visible').hasClass('last')) {
                    $nav_panels.children('.more').show();
                } else {
                    $nav_panels.children('.more').hide();
                }

                if (!$nav_panels.children('.page_link:visible').hasClass('first')) {
                    $nav_panels.children('.less').show();
                } else {
                    $nav_panels.children('.less').hide();
                }
            }

            /* Add the style class ".no_more" to the first/prev and last/next links to allow custom styling */
            function tagNextPrev() {
                if ($nav_panels.children('.last').hasClass('active_page')) {
                    $nav_panels.children('.next_link').add('.last_link').addClass('no_more');
                } else {
                    $nav_panels.children('.next_link').add('.last_link').removeClass('no_more');
                }

                if ($nav_panels.children('.first').hasClass('active_page')) {
                    $nav_panels.children('.previous_link').add('.first_link').addClass('no_more');
                } else {
                    $nav_panels.children('.previous_link').add('.first_link').removeClass('no_more');
                }
            }
        });
    };

})(jQuery);