/*  gaTracker 1.0.1: jQuery Google Analytics Integration
  A quicker, automated way to embed Google Analytics.
  (c)2007 Jason Huck/Core Five Creative

  * BETA Support for new Analytics API (ga.js) by Jamie Thompson - http://jamazon.co.uk
  * Requires jQuery 1.2.x or higher (for cross-domain $.getScript)
  * TODO: more testing, delay after $.getScript for Safari

  Usage:
  Only a tracking code is required:
  $.gaTracker('UA-XXXXX-XX');

  ...but other options can be specified:
  $.gaTracker(
    'UA-XXXXX-XX',
    {
      external: '/external/',
      mailto:   '/mailto/',
      download: '/downloads/',
      extensions: [
        'pdf','doc','xls','csv','jpg','gif', 'mp3',
        'swf','txt','ppt','zip','gz','dmg','xml'
      ]
    }
  );

*/


(function($){
  $.gaTracker = function(code, opts){
    opts = jQuery.extend({
      external: '/external/',
      mailto:   '/mailtos/',
      download: '/downloads/',
      extensions: [
          'pdf','doc','xls','csv','jpg','gif', 'mp3',
          'swf','txt','ppt','zip','gz','dmg','xml', 'js'
      ]
    }, opts);

    // Returns the given URL prefixed if it is:
    //    a) a link to an external site
    //    b) a mailto link
    //    c) a downloadable file
    // ...otherwise returns an empty string.
    function decorateLink(u){
      var trackingURL = '';

      if(u.indexOf('://') == -1 && u.indexOf('mailto:') != 0){
        // no protocol or mailto - internal link - check extension
        var ext = u.split('.')[u.split('.').length - 1];
        var exts = opts.extensions;

        for(i = 0; i < exts.length; i++){
          if(ext == exts[i]){
            trackingURL = opts.download + u;
            break;
          }
        }
      } else {
        if(u.indexOf('mailto:') == 0){
          // mailto link - decorate
          trackingURL = opts.mailto + u.substring(7);
        } else {
          // complete URL - check domain
          var regex = /([^:\/]+)*(?::\/\/)*([^:\/]+)(:[0-9]+)*\/?/i;
          var linkparts = regex.exec(u);
          var urlparts = regex.exec(location.href);
          if(linkparts[2] != urlparts[2]) trackingURL = opts.external + u;
        }
      }

      return trackingURL;
    }

    // add tracking code to the current page
    function addTracking(){
      $.pageTracker = _gat._getTracker(code);
      $.pageTracker._initData();
      $.pageTracker._trackPageview();

      // examine every link in the page
      $('a').each(function(){
        var u = $(this).attr('href');

        if(typeof(u) != 'undefined'){
          var newLink = decorateLink(u);

          // if it needs to be tracked manually,
          // bind a click event to call GA with
          // the decorated/prefixed link
          if(newLink.length){
            $(this).click(function(){
              $.pageTracker._trackPageview(newLink);
            });
          }
        }
      });
    }

    // include the external GA script in try/catch to play nice
    function initGA(){
      try{
        // determine whether to include the normal or SSL version
        var gaURL = (location.href.indexOf('https') == 0 ? 'https://ssl' : 'http://www');
        gaURL += '.google-analytics.com/ga.js';

        // include the script
        $.getScript(gaURL, function(){
          addTracking();
        });
      } catch(err) {
        // log any failure
        console.log('Failed to load Google Analytics:' + err);
      }
    }

    initGA();
  }
})(jQuery);