;(function($){
/*******************************************************************************************/  
// jquery.pajinate.js - version 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: 2010-04-26
/*******************************************************************************************/

  $.fn.pajinate = function(options){
    // Set some state information
    var current_page = 'current_page';
    var items_per_page = 'items_per_page';
    
    var meta;
  
    // 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,
      nav_label_first : 'First',
      nav_label_prev : 'Prev',
      nav_label_next : 'Next',
      nav_label_last : 'Last'
    };
    var options = $.extend(defaults,options);
    var $item_container;
    var $page_container;
    var $items;
    var $nav_panels;
  
    return this.each(function(){
      $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 navigation_html = '<a class="first_link" href="">'+ options.nav_label_first +'</a>';
      navigation_html += '<a class="previous_link" href="">'+ options.nav_label_prev +'</a>'+ 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 + '<a class="next_link" href="">'+ options.nav_label_next +'</a>';
      navigation_html += '<a class="last_link" href="">'+ options.nav_label_last +'</a>';
      
      // And add it to the appropriate area of the DOM  
      $nav_panels = $page_container.find(options.nav_panel_id);      
      $nav_panels.html(navigation_html).each(function(){
      
        $(this).find('.page_link:first').addClass('first');
        $(this).find('.page_link:last').addClass('last');
        
      });
      
      // 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
      
      var total_page_no_links = $page_container.children(options.nav_panel_id+':first').children('.page_link').size();
      options.num_page_links_to_display = Math.min(options.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, options.num_page_links_to_display).show();      
      });
      
      /* Bind the actions to their respective links */
       
      // Event handler for 'First' link
      $page_container.find('.first_link').click(function(e){
        e.preventDefault();
        
        movePageNumbersRight($(this),0);
        goto(0);        
      });      
      
      // Event handler for 'Last' link
      $page_container.find('.last_link').click(function(e){
        e.preventDefault();
        var lastPage = total_page_no_links - 1;
        movePageNumbersLeft($(this),lastPage);
        goto(lastPage);        
      });      
      
      // Event handler for 'Prev' link
      $page_container.find('.previous_link').click(function(e){
        e.preventDefault();
        showPrevPage($(this));
      });
      
      
      // Event handler for 'Next' link
      $page_container.find('.next_link').click(function(e){
        e.preventDefault();        
        showNextPage($(this));
      });
      
      // Event handler for each 'Page' link
      $page_container.find('.page_link').click(function(e){
        e.preventDefault();
        goto($(this).attr('longdesc'));
      });      
      
      // Goto the required page
      goto(parseInt(options.start_page));
      toggleMoreLess();
    });
    
    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);
        goto(new_page);
      }
        
    };
      
    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);
        goto(new_page);
      }
        
    };
      
    function goto(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();
    };  
    
    // 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 - options.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(options.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();
      }      
    }
    
  };
  
})(jQuery);