One customTask to rule them all.

customTaskMonster

var _customTask = function () {
  // customTask Builder by Simo Ahava
  //
  // More information about customTask: https://www.simoahava.com/analytics/customtask-the-guide/
  //
  // Change the default values for the settings below.

  // clientIdIndex: The Custom Dimension index to where you want to send the visitor's Client ID.
  // https://bit.ly/2Ms0ZcC  
  var clientIdIndex = 1;

  // hitTypeIndex: The Custom Dimension index to where you want to send the hit type of the request.
  // https://bit.ly/2KZqLA9
  var hitTypeIndex = 2;

  // payloadLengthIndex: The Custom Dimension index to where you want to send the length of the payload of the request.
  // https://bit.ly/2PdhPKM
  var payloadLengthIndex = 3;

  // removeCustomDefinitionsFromTimingHits: Set to true if you want to remove Custom Dimensions and Custom Metrics from the page speed timing hit.
  // https://bit.ly/2nGzw8T
  var removeCustomDefinitionsFromTimingHits = true;

  // duplicateHitToTrackingIds: Array of all Universal Analytics tracking IDs to where you want to duplicate the initial hit.
  // https://bit.ly/2MwFGGP
  var duplicateHitToTrackingIds = ['UA-12345-1'];

  // piiRegex: Array of {name, regex} objects, where the regular expression matches a pattern you want to replace with [REDACTED name].
  // https://bit.ly/2wcJym2
  var piiRegex = [{
    name: 'EMAIL',
    regex: /.{4}@.{4}/g
  }];

  // snowplowEndpoint: The Snowplow collector endpoint to which you want to send the GA request hit payload.
  // https://bit.ly/2OCBzXc
  var snowplowEndpoint = 'https://collector.simoahava.com/';

  // updateSessionCookie: Object which contains both an expiration time (in milliseconds) and domain name.
  // https://bit.ly/2wh1xsH
  var updateSessionCookie = {
    expiresMs: 1000 * 60 * 30,
    domain: 'mydomain.com'
  };

  // iframeDecorator: Configuration object for decorating any iframe with cross-domain parameters when this customTask is run.
  // https://bit.ly/2LUoWFf
  var iframeDecorator = {
    selector: 'iframe#decorateMe',
    attempts: 10,
    intervalMs: 1000,
    useAnchor: false
  };

  // transactionDeduper: Configuration object for preventing duplicate transactions from being recorded.
  // https://bit.ly/2AvSZ2Y
  var transactionDeduper = {
    keyName: '_transaction_ids',
    cookieExpiresDays: 365
  };

  // obfuscate: Obfuscates the entire hit payload (using a dictionary of words consistently) and dispatches it to the trackingId you provide.
  // https://bit.ly/2RectUl
  var obfuscate = {
    tid: 'UA-12345-1',
    dict: ['tumble', 'noble', 'flourish', 'abandon', 'liberal', 'team', 'conflict', 'collar', 'tiger', 'stun', 'grace', 'resource', 'phantom', 'imagine', 'information', 'hall', 'sweet', 'agriculture', 'bingo', 'relative'],
    stringParams: ['uid','ua','dr','cn','cs','cm','ck','cc','ci','gclid','dclid','dl','dh','dp','dt','cd','cg[1-5]','linkid','an','aid','av','aiid','ec','ea','el','ti','ta','in','ic','iv','pr\\d{1,3}id','pr\\d{1,3}nm','pr\\d{1,3}br','pr\\d{1,3}ca','pr\\d{1,3}va','pr\\d{1,3}cc','pr\\d{1,3}cd\\d{1,3}','tcc','pal','col','il\\d{1,3}nm','il\\d{1,3}pi\\d{1,3}id','il\\d{1,3}pi\\d{1,3}nm','il\\d{1,3}pi\\d{1,3}br','il\\d{1,3}pi\\d{1,3}ca','il\\d{1,3}pi\\d{1,3}va','il\\d{1,3}pi\\d{1,3}cd\\d{1,3}','promo\\d{1,3}id','promo\\d{1,3}nm','promo\\d{1,3}cr','promo\\d{1,3}ps','sn','sa','st','utc','utv','utl','exd','cd\\d{1,3}','xid','exp','_utmz'],
    priceParams: ['tr','ts','tt','ip','pr\\d{1,3}pr','id\\d{1,3}pi\\d{1,3}pr'],
    priceModifier: Math.random(),
    medium: ['organic', 'referral', 'social', 'cpc'],
    replaceString: function(t){if(''===t)return t;'function'==typeof window.btoa&&(t=btoa(t));var n=t.split('').map(function(t){return t.charCodeAt(0)}).join('')%obfuscate.dict.length;return obfuscate.dict[n]},
    init: function(){var c=[];obfuscate.dict.forEach(function(t){obfuscate.dict.forEach(function(o){c.push(t+'-'+o)})}),obfuscate.dict=obfuscate.dict.concat(c)}
  };
  
  // localStorageCid: Use localStorage to persist Client ID with Google Analytics tags
  // https://bit.ly/2GNElc4
  var localStorageCid = {
    objectName: 'ga_client_id',
    expires: 1000*60*60*24*365*2
  };

  // DO NOT EDIT ANYTHING BELOW THIS LINE
  if (typeof obfuscate === 'object' && typeof obfuscate.init === 'function') obfuscate.init();

  var readFromStorage = function (key) {
    if (!window.Storage) {
      // From: https://stackoverflow.com/a/15724300/2367037
      var value = '; ' + document.cookie;
      var parts = value.split('; ' + key + '=');
      if (parts.length === 2) {
        return parts.pop().split(';').shift();
      }
    } else {
      return window.localStorage.getItem(key);
    }
  };

  var writeToStorage = function (key, value, expireDays) {
    if (!window.Storage) {
      var expiresDate = new Date();
      expiresDate.setDate(expiresDate.getDate() + expireDays);
      document.cookie = key + '=' + value + ';expires=' + expiresDate.toUTCString();
    } else {
      window.localStorage.setItem(key, value);
    }
  };

  var globalSendHitTaskName   = '_ga_originalSendHitTask';

  return function (customTaskModel) {

    window[globalSendHitTaskName] = window[globalSendHitTaskName] || customTaskModel.get('sendHitTask');

    // clientIdIndex
    if (typeof clientIdIndex === 'number') {
      customTaskModel.set('dimension' + clientIdIndex, customTaskModel.get('clientId'));
    }
    // /clientIdIndex

    // hitTypeIndex
    if (typeof hitTypeIndex === 'number') {
      customTaskModel.set('dimension' + hitTypeIndex, customTaskModel.get('hitType'));
    }
    // /hitTypeIndex

    // removeCustomDefinitionsFromTimingHits
    if (typeof removeCustomDefinitionsFromTimingHits === 'boolean' && removeCustomDefinitionsFromTimingHits === true) {
      if (customTaskModel.get('hitType') === 'timing') {
        var _rcd_tempFieldObject = {};
        var _rcd_dimensionIndex = 1;
        while (_rcd_dimensionIndex !== 201) {
          _rcd_tempFieldObject['dimension' + _rcd_dimensionIndex] = undefined;
          _rcd_tempFieldObject['metric' + _rcd_dimensionIndex] = undefined;
          _rcd_dimensionIndex++;
        }
        customTaskModel.set(_rcd_tempFieldObject);
      }
    }
    // /removeCustomDefinitionsFromTimingHits

    // iframeDecorator
    if (typeof iframeDecorator === 'object' && typeof iframeDecorator.selector === 'string' && typeof iframeDecorator.attempts === 'number' && typeof iframeDecorator.intervalMs === 'number') {
      var _id_decorateTimer;
      var _id_count = 0;
      var _id_ga = window[window['GoogleAnalyticsObject']];
      var _id_tracker = _id_ga.getByName(customTaskModel.get('name'));
      var _id_decorateIframe = function () {
        var _id_iframe = document.querySelector(iframeDecorator.selector);
        if (_id_iframe !== null && /[?&]_ga=/.test(_id_iframe.src)) {
          window.clearInterval(_id_decorateTimer);
          return;
        }
        if (_id_iframe === null) {
          _id_count += 1;
          if (_id_count === iframeDecorator.attempts) {
            window.clearInterval(_id_decorateTimer);
          }
          return;
        }
        window.clearInterval(_id_decorateTimer);
        _id_iframe.src = (new window.gaplugins.Linker(_id_tracker)).decorate(_id_iframe.src, iframeDecorator.useAnchor);
      };
      _id_decorateTimer = window.setInterval(_id_decorateIframe, iframeDecorator.intervalMs);
    }
    // /iframeDecorator
    
    // localStorageCid
    if (typeof localStorageCid === 'object' && typeof localStorageCid.objectName === 'string' && typeof localStorageCid.expires === 'number' && window.Storage) {
      var _lsc_clientId = customTaskModel.get('clientId');
      var _lsc_obj = JSON.stringify({
        clientId: _lsc_clientId,
        expires: localStorageCid.expires
      });
      window.localStorage.setItem(localStorageCid.objectName, _lsc_obj);
    }
    // /localStorageCid

    customTaskModel.set('sendHitTask', function (sendHitTaskModel) {

      var originalSendHitTaskModel = sendHitTaskModel,
          originalSendHitTask      = window[globalSendHitTaskName],
          canSendHit               = true;

      try {

        // transactionDeduper
        if (typeof transactionDeduper === 'object' && transactionDeduper.hasOwnProperty('keyName') && transactionDeduper.hasOwnProperty('cookieExpiresDays') && typeof sendHitTaskModel.get('&ti') !== 'undefined') {
          var _td_transactionId = sendHitTaskModel.get('&ti');
          var _td_storedIds = JSON.parse(readFromStorage(transactionDeduper.keyName) || '[]');
          if (_td_storedIds.indexOf(_td_transactionId) > -1 && ['transaction', 'item'].indexOf(sendHitTaskModel.get('hitType')) === -1) {
            canSendHit = false;
          } else if (_td_storedIds.indexOf(_td_transactionId) === -1) {
            _td_storedIds.push(_td_transactionId);
            writeToStorage(transactionDeduper.keyName, JSON.stringify(_td_storedIds), transactionDeduper.cookieExpiresDays);
          }
        }
        // /transactionDeduper

        // piiRegex
        if (typeof piiRegex !== 'undefined' && piiRegex.length) {
          var _pr_hitPayloadParts = sendHitTaskModel.get('hitPayload').split('&');
          for (var _pr_regexI = 0; _pr_regexI < _pr_hitPayloadParts.length; _pr_regexI++) {
            var _pr_param = _pr_hitPayloadParts[_pr_regexI].split('=');
            var _pr_val;
            try {
              _pr_val = decodeURIComponent(decodeURIComponent(_pr_param[1]));
            } catch(e) {
              _pr_val = decodeURIComponent(_pr_param[1]);
            }
            piiRegex.forEach(function(pii) {
              _pr_val = _pr_val.replace(pii.regex, '[REDACTED ' + pii.name + ']');
            });
            _pr_param[1] = encodeURIComponent(_pr_val);
            _pr_hitPayloadParts[_pr_regexI] = _pr_param.join('=');
          }
          sendHitTaskModel.set('hitPayload', _pr_hitPayloadParts.join('&'), true);
        }
        // /piiRegex

        // payloadLengthIndex
        if (typeof payloadLengthIndex === 'number') {
          var _pl_hitPayload = sendHitTaskModel.get('hitPayload');
          _pl_hitPayload += '&cd' + payloadLengthIndex + '=';
          _pl_hitPayload += (_pl_hitPayload.length + _pl_hitPayload.length.toString().length);
          sendHitTaskModel.set('hitPayload', _pl_hitPayload, true);
        }
        // /payloadLengthIndex

        if (canSendHit) {
          originalSendHitTask(sendHitTaskModel);
        }

        // snowplowEndpoint
        if (typeof snowplowEndpoint === 'string') {
          var _sp_hitPayload = sendHitTaskModel.get('hitPayload');
          var _sp_snowplowVendor = 'com.google.analytics';
          var _sp_snowplowVersion = 'v1';
          var _sp_snowplowPath = (snowplowEndpoint.substring(snowplowEndpoint.length-1) !== '/' ? snowplowEndpoint + '/' : snowplowEndpoint) + _sp_snowplowVendor + '/' + _sp_snowplowVersion;
          var _sp_request = new XMLHttpRequest();
          _sp_request.open('POST', _sp_snowplowPath, true);
          _sp_request.setRequestHeader('Content-type', 'text/plain; charset=UTF-8');
          _sp_request.send(_sp_hitPayload);
        }
        // /snowplowEndpoint

        // duplicateHitToTrackingIds
        if (typeof duplicateHitToTrackingIds !== 'undefined' && duplicateHitToTrackingIds.length) {
          var _dh_hitPayload = sendHitTaskModel.get('hitPayload');
          var _dh_originalTrackingId = new RegExp(sendHitTaskModel.get('trackingId'), 'gi');
          duplicateHitToTrackingIds.forEach(function(newTrackingId) {
            sendHitTaskModel.set('hitPayload', _dh_hitPayload.replace(_dh_originalTrackingId, newTrackingId), true);
            if (canSendHit) {
              originalSendHitTask(sendHitTaskModel);
            }
          });
        }
        // /duplicateHitToTrackingIds

        // updateSessionCookie
        if (typeof updateSessionCookie === 'object' && updateSessionCookie.hasOwnProperty('expiresMs') && updateSessionCookie.hasOwnProperty('domain')) {
          var _sc_hitType = sendHitTaskModel.get('hitType');
          var _sc_nonInteraction = sendHitTaskModel.get('nonInteraction');
          if (_sc_nonInteraction !== true && (_sc_hitType === 'pageview' || _sc_hitType === 'event')) {
            var _sc_d = new Date();
            _sc_d.setTime(_sc_d.getTime() + updateSessionCookie.expiresMs);
            document.cookie = '_session_' + sendHitTaskModel.get('trackingId') + '=true; expires=' + _sc_d.toUTCString() + '; path=/; domain=' + updateSessionCookie.domain;
          }
        }
        // /updateSessionCookie

        // obfuscate
        if (typeof obfuscate === 'object' && obfuscate.hasOwnProperty('tid') && obfuscate.hasOwnProperty('dict') && obfuscate.hasOwnProperty('stringParams') && obfuscate.hasOwnProperty('priceParams') && obfuscate.hasOwnProperty('replaceString') && obfuscate.hasOwnProperty('priceModifier')) {
          var _o_hitPayload = sendHitTaskModel.get('hitPayload');
          obfuscate.stringParams.forEach(function(strParam) {
            var regexParam = new RegExp('[?&]' + strParam + '=[^&]+', 'g');
            var paramsInHitpayload = _o_hitPayload.match(regexParam) || [];
            paramsInHitpayload.forEach(function(keyValue) {
              var parts = keyValue.split('=');
              var urlParts = parts[1].split('%2F').map(function(urlPart) {
                if (/https?:/.test(decodeURIComponent(urlPart))) return urlPart;
                return urlPart.split('%20').map(function(wordPart) {
                  return obfuscate.replaceString(wordPart);
                }).join('%20');
              }).join('%2F');
              _o_hitPayload = _o_hitPayload.replace(parts.join('='), parts[0] + '=' + urlParts);
            });
          });
          obfuscate.priceParams.forEach(function(prParam) {
            var regexParam = new RegExp('[?&]' + prParam + '=[^&]+', 'g');
            var paramsInHitpayload = _o_hitPayload.match(regexParam) || [];
            paramsInHitpayload.forEach(function(keyValue) {
              var parts = keyValue.split('=');
              var price = parseFloat(parts[1]) || 0.00;
              price = (price * obfuscate.priceModifier).toFixed(2);
              _o_hitPayload = _o_hitPayload.replace(parts.join('='), parts[0] + '=' + price);
            });
          });
          _o_hitPayload = _o_hitPayload
            .replace(
              '&tid=' + sendHitTaskModel.get('trackingId') + '&', 
              '&tid=' + obfuscate.tid + '&'
            )
            .replace(/[?&]aip($|&|=[^&]*)/, '')
            .replace(/[?&]c[sm]=[^&]*/g, '')
            .replace(/[?&]uip=[^&]*/g, '');
          if (Math.random() <= 0.10) {
            _o_hitPayload += 
              '&cs=' + obfuscate.dict[Math.floor(Math.random()*obfuscate.dict.length)] + 
              '&cm=' + obfuscate.medium[Math.floor(Math.random()*obfuscate.medium.length)];
          }
          _o_hitPayload += '&uip=' + 
            (Math.floor(Math.random() * 255) + 1) + '.' +
            (Math.floor(Math.random() * 255) + 0) + '.' +
            (Math.floor(Math.random() * 255) + 0) + '.' +
            (Math.floor(Math.random() * 255) + 0);
          _o_hitPayload += '&aip=1';
          sendHitTaskModel.set('hitPayload', _o_hitPayload, true);
          originalSendHitTask(sendHitTaskModel);
        }
        // /obfuscate

      } catch(err) {
        originalSendHitTask(originalSendHitTaskModel);
      }

    });

  };
};