var TGAMD = window.TGAMD || {};
TGAMD.ads.sticky = (function($) {

var $halfpage = $('#halfpager-art-1'),
    $page = $('#page'),
    $primary = $('.primary'),
    $tertiary = $('.tertiary'),
    $content = $('#content'),
    $secondary = $('.secondary'),
    $stickyRail = '';

var contentOffset = $content.offset().top,
    tertiaryOffset = $tertiary.offset().top,
    halfpageHeight = $halfpage.height()+55,
    primaryHeight = $primary.height(),
    secondaryHeight = $secondary.height(),
    stickyRailHeight = '';

var boxPos = tertiaryOffset-halfpageHeight-contentOffset,
    halfPos = ((tertiaryOffset - halfpageHeight)+35),
    newPos = halfpageHeight > 600 ? halfPos : boxPos;

function init(){
      if ( primaryHeight < (secondaryHeight+600) && typeof $.waypoints == 'undefined' ) { return; }
      $halfpage.nextAll('section').addClass('stickyAd--rail');
      $stickyRail = $('.stickyAd--rail');
      stickyRailHeight = $stickyRail.height();

      $halfpage.waypoint({
            handler: function(evt,dir) {
                $page.toggleClass('stickyAd', dir === 'down');
                $stickyRail.css({'top': halfpageHeight+'px'});
                if(dir === 'up'){
                  $stickyRail.removeAttr('style');
                }
            }
      });
      $tertiary.waypoint({
            handler: function(evt,dir) {
                if(dir==='up'){
                  $halfpage.removeAttr('style');
                  $stickyRail.css({'position': 'fixed', 'top': halfpageHeight+'px'});
                }
                if(dir==='down'){
                  $secondary.css({'position': 'relative'});
                  $halfpage.css({'position': 'absolute','z-index':'inherit','top':  boxPos-stickyRailHeight+'px'});
                  $stickyRail.css({'position': 'absolute','top': newPos+'px'});
                }
            },
            offset: halfpageHeight+stickyRailHeight
      });
}
return {
     init: init
};
})(jQuery);