var wrtmc_ad_fullpage_timer;
var wrtmc_ad_rotation_speed = 0;
var wrtmc_ad_scrolltop_limit = 100000;


function wrtmc_ad_resize_fullpage( pane ) {
   var image_width   = $('img', pane ).width();
   var window_width  = $(window).width();
   var content_width = $('#b_content').width();
   var half_diff_width = ( Math.max( window_width, content_width ) - image_width ) / 2;

   pane.height( $(document).height() - 100 );

   // Move the ad pane so it is centred in the screen.
   pane.css('left', half_diff_width );
}




function wrtmc_ad_fullpage_change( link ) {
   var self = link;

   if( self.hasClass('on') ) { return; }
   if( $(document).scrollTop() > wrtmc_ad_scrolltop_limit ) { return; }

   var index = self.prevAll().length + 1;
   var current = $('#wrtmc_ad_fullpage .pane.on');
   var next    = $('#wrtmc_ad_fullpage .pane:nth-child('+ index +')');

   next.css('zIndex', 99 );
   next.fadeIn( 800, function() {
      current.removeClass('on').hide();
      next.addClass('on').css('zIndex', 20 );

      $('body').css('backgroundColor', next.css('backgroundColor') );

      $('#wrtmc_ad_fullpage .nav .on').removeClass('on');
      self.addClass('on');
   });
}




function wrtmc_ad_fullpage_init() {
   var wrtmc_ad_panes = $('#wrtmc_ad_fullpage .pane');


   // Set the height of the full page ads to the background
   // height of the screen. This way we can possibly fade 
   // the background colours as well as the ad.
   $('#wrtmc_ad_fullpage').height( $(document).height() - 100 );

   // On resize, make sure that we keep the full page ad centred
   $( window ).resize( function() {
      wrtmc_ad_panes.each( function() {
         wrtmc_ad_resize_fullpage( $(this) );
      });
   }).resize();


   // Initialize the Navigation
   if( wrtmc_ad_panes.length > 1 ) {
      $('#wrtmc_ad_fullpage').append('<ul class="nav anchor" />');
      for( var i=0; i < wrtmc_ad_panes.length; i++ ){
         $('#wrtmc_ad_fullpage .nav').append('<li></li>');
      }

      $('#wrtmc_ad_fullpage .nav li').live('click', function( e ) {
         wrtmc_ad_fullpage_change( $(this) );
         clearTimeout( wrtmc_ad_fullpage_timer );

         var label = $(this).prevAll().length + 1;
         wrtmc_track_event({
            'category': 'Full Page Ad',
            'action':   'Change Index',
            'label':    label
         });

         e.preventDefault();
      });
   }


   $('#wrtmc_ad_fullpage .content').click( function() {
      var url = $('a.go', $(this) ).attr('href');
      window.location = url;
   });


   wrtmc_ad_panes.first().show();
   wrtmc_ad_fullpage_change( $('#wrtmc_ad_fullpage .nav li:first') );

   if( 0 < wrtmc_ad_rotation_speed ) {
      wrtmc_ad_fullpage_timer = setTimeout( wrtmc_ad_fullpage_rotate, wrtmc_ad_rotation_speed );
   }
}



function wrtmc_ad_fullpage_rotate() {
   var current = $('#wrtmc_ad_fullpage .nav .on');
   next = current.next();
   if( !next.length ){ next = $('#wrtmc_ad_fullpage .nav li:first'); }
   if( next.length ) { wrtmc_ad_fullpage_change( next ); }

   if( 0 < wrtmc_ad_rotation_speed ) {
      wrtmc_ad_fullpage_timer = setTimeout( wrtmc_ad_fullpage_rotate, wrtmc_ad_rotation_speed );
   }
}