Helper functions

/*
 * Usage
 *    This function returns the value of the cookie name passed in as the argument.
 *
 *  @param {String} name - The name of the cookie.
 */

 var getCookie = function(name) {
   var match = document.cookie.match(name+'=([^;]*)');
   return match ? match[1] : undefined;
 };

/*
 * Usage
 *    This function sets a cookie on the visitor's browser.
 *
 *  @param {String} c_name - The name of the cookie.
 *  @param {String} value - The value of the cookie.
 *  @param {Float} exdays - The number of days the cookie should last.
 *  @param {String} c_domain - The domain on which this cookie should be set and can be read.

 *
 */

 var setCookie = function(c_name,value,exdays,c_domain) {
   c_domain = (typeof c_domain === "undefined") ? "" : "domain=" + c_domain + ";";
   var exdate=new Date();
   exdate.setDate(exdate.getDate() + exdays);
   var c_value=escape(value) + ((exdays==null) ? "" : "; expires="+exdate.toUTCString());
   document.cookie=c_name + "=" + c_value + ";" + c_domain + "path=/";
 }

var utils = window["optimizely"].get("utils");

var cancelPolling = utils.poll(function() {
  if (typeof accountBalance !== 'number') {
    if (accountBalance <=20) {
      headerElement.innerHTML = 'Your account balance is low! Add funds';
    } else {
      headerElement.innerHTML = 'Your account balance is in good standing.';
    }
  cancelPolling();
  }
}, 1000);

/*
 * Usage
 *    This function appends an external JavaScript to the head of the document.
 *
 *  @param {String} location - The location of the file you'd like to load.
 *  @param {Function} callback - [OPTIONAL] A function to call when the script has completed downloading.
 *
 */

 var loadScript = function(location, callback){
   var fileRef = document.createElement('script');
   fileRef.setAttribute('type','text/javascript');

   if (callback) {
     if (fileRef.readyState) {  // IE
       fileRef.onreadystatechange = function() {
         if (fileRef.readyState == 'loaded' || fileRef.readyState == 'complete') {
           fileRef.onreadystatechange = null;
           callback();
         }
       };
     } else {  // Non-IE
       fileRef.onload = function(){
         callback();
       };
     }
   }

   fileRef.setAttribute('src', location);
   document.head.appendChild(fileRef);
 };

 loadScript('http://www.example.com/test.js', function() {
   // CALLBACK - code that does something with the data returned by loading the script
 });

/*
 * Usage
 *    This function takes a query parameter name and returns its value.
 *
 *  @param {String} name - The name of the query parameter, whose value you want returned.
 */

 var getQueryParam = function(name) {
   var match = window.location.search.match(name + '=([^&]*)');
   return match ? match[1] : undefined;
 }

 // example showing the function called, with the return value inserted in the first h1 element
 $('h1:eq(0)').text(getQueryParam('myParam'));

/*
 *  Usage
 *     Pass in the ID of an element whose position you want fixed once the visitor scrolls past the element's initial position.  
 *     If the visitor scrolls up again, the element takes on its original position.
 *
 *  @param {String} id - The CSS ID of the element you want to have fixed position.
 *
 */

 var makeSticky = function(id) {
   var menuOffset = document.getElementById(id).offsetTop;
   var docScroll = $(document).scrollTop();
   $(document).bind('ready scroll', function() {
     docScroll = $(document).scrollTop();
     if(docScroll >= menuOffset) {
       $('#'+id).css({'position':'fixed', 'top':'0', 'z-index': '1000'});
     } else {
       $('#'+id).css({'position':'initial','z-index':'0'});
     }
   });
 }

 // Usage example
 makeSticky('mainNavBar');

/*
 * Example showing how to reference a variable defined natively on the page from inside Optimizely.
 */

 // Variation code example injecting the 'visitorName' property of the 'exampleObject' in the h3 elements
 $('h3').text('Hello,' + window.exampleObject['visitorName']);

/*
 * Get active Experiment IDs and their Variation IDs for both Optimizely X Web Experiments and Personalization Campaigns.
 */

var activeCampaigns = optimizely.get('state').getCampaignStates({isActive:true});

for (var key in activeCampaigns) {
  if (activeCampaigns.hasOwnProperty(key)) {
    console.log("ExperimentId: " + activeCampaigns[key].experiment.id + ", variationId: " + activeCampaigns[key].variation.id);
  }
}

function getActiveTags() {
  var pages = optimizely.get('state').getPageStates()
  var activePages = pages ? Object.values(pages).filter(function(page) {
    return page.isActive && page.tags.length
  }) : []
  var tags = []
  activePages.forEach(function(page) {
    tags = tags.concat(Object.values(page.metadata))
  })
  return tags
}