/**
 * Google Preview
 *
 * @author Ryan Chase
 * @version 1.0
 * @url http://www.blastam.com/blog/index.php/2013/03/how-to-track-downloads-in-google-analytics-v2
 */
document.addEventListener('DOMContentLoaded', function(event) {
  var filetypes = /\.(zip|exe|dmg|pdf|doc.*|xls.*|ppt.*|mp3|txt|rar|wma|mov|avi|wmv|flv|wav)$/i;

  document.querySelector('a').addEventListener('click', function(event) {
    var track = true,
      href = this.href,
      isThisDomain = href.match(document.domain.split('.').reverse()[1] + '.' + document.domain.split('.').reverse()[0]);

    if(!href.match(/^javascript:/i)) {
      var elEv = [];
      elEv.value = 0, elEv.non_i = false;
      if(href.match(/^mailto\:/i)) {
        elEv.category = "email";
        elEv.action = "click";
        elEv.label = href.replace(/^mailto\:/i, '');
        elEv.loc = href;
      } else if(href.match(filetypes)) {
        var extension = (/[.]/.exec(href)) ? /[^.]+$/.exec(href) : undefined;
        elEv.category = "download";
        elEv.action = "click-" + extension[0];
        elEv.label = href.replace(/ /g, "-");
        elEv.loc = href;
      } else if(href.match(/^https?\:/i) && !isThisDomain) {
        elEv.category = "external";
        elEv.action = "click";
        elEv.label = href.replace(/^https?\:\/\//i, '');
        elEv.non_i = true;
        elEv.loc = href;
      } else if(href.match(/^tel\:/i)) {
        elEv.category = "telephone";
        elEv.action = "click";
        elEv.label = href.replace(/^tel\:/i, '');
        elEv.loc = href;
      } else track = false;

      if(track) {
        ga('send', 'event', elEv.category.toLowerCase(), elEv.action.toLowerCase(), elEv.label.toLowerCase(), elEv.value, {'nonInteraction': elEv.non_i});
      }
    }
  });
});