$(function()
{
  // ul-list
  var $ul = $('#sidebar ul.nav');
  var $ul_second = $('#top-menu ul.nav');
  
  // $current list css class
  var $current_list_css_class = 'current_list';
  
  $ul.addClass('current_list');

  // current css-class
  var $current_css_class = 'current_page_item';

  // current element
  var $current = $('.current_list li.' + $current_css_class);

  // current list
  var $list = $current.parent().parent().attr('id');

  // length of ul-lists
  var $length = $current.parent().find('> li').length;

  // content
  var $content = $('#content');

  // navigation
  var $a_prev = $('a#squish-slider-prev');
  var $a_next = $('a#squish-slider-next');

  // header
  var $header = $('#header');

  /**
   *
   */
  $a_prev.click(function(event)
  {
    event.preventDefault();

    if ($current.index() <= 0)
    {
      if($list == 'sidebar')
      {
        $current = switchContent($ul_second.find('li:last'));
        $length = $ul_second.find('li').length;
        $list = 'top-menu';
      }
        else
      {
        $current = switchContent($('#sidebar ul.nav > li:last'));
        $length = $('#sidebar ul.nav > li').length;
        $list = 'sidebar';
      }
    }
      else
    {
      $current = switchContent($current.prev());
    }
  });

  /**
   * 
   */
  $a_next.click(function(event)
  {
    event.preventDefault();

    if ($current.index() >= ($length - 1))
    {
      if ($list == 'sidebar')
      {
        $current = switchContent($ul_second.find('li:first'));
        $length = $ul_second.find('li').length;
        $list = 'top-menu';
      }
        else
      {
        $current = switchContent($('#sidebar ul.nav > li:first'));
        $length = $('#sidebar ul.nav > li').length;
        $list = 'sidebar';
      }
    }
      else
    {
      $current = switchContent($current.next());
    }
  });

  function switchContent($element)
  {
    $current.removeClass($current_css_class);
    $element.addClass($current_css_class);

    $header.find('.overlay').show();
	
    $.ajax({
      type     : "get",
      url      : $element.find('a').attr('href'),
      dataType : "html",
      success  : function(data)
      {
        $header.find('.overlay').hide();

        // new image from data
        var $img = $(data).find('#header-img img');

        // header image
        var $header_img = $('#header-img img');

        // at start there can bee only one image
        $('#header-img img:gt(0)').remove();
        
        $header_img.fadeOut('slow', function()
        {
          $(this).remove();
        });

        $('#header-img').append($img).fadeIn('slow');
        $content.hide().html($(data).find('#content').html()).fadeIn();
		$('#linkbar').hide().html($(data).find('#linkbar').html()).fadeIn();
        $header.find('div.title').html($(data).find('#header div.title').html());
		$('div#logo').html($(data).find('div#logo').html());
		video();
      }
    });

    return $element;
  }
});