/*
 *  producer-tracking.js
 *  Author: Adam Bratt
 *  Version: 0.1
 *  Date: September 15, 2014
 *  Description:
 *
 *  Allows Marketfy.com Mavens to track sales originating from their personal
 *  sites and promotional landing pages.
 *
 */

MarketfyToolkit = window.MarketfyToolkit || {};
MarketfyToolkit.version = '0.3.1';


/**
 * Instantaneously invoked function to wrap tracker script. We bind the
 * tracker creation to the MarketfyToolkit global at the end of the invocation.
 *
 * @param {window} window
 * @param {document} document
 * @param {MarketfyToolkit) toolkit Global instance of our Marketfy Toolkit
 *
 */
!function(window, document, toolkit, undefined) {

  // Check to see if already loaded this script
  if (toolkit.sessionTracker)
    return;

  /**
   * Marketfy Session Tracker Class for handling all types of session tracking
   * on external partner websites.
   *
   * @param {object} options Settings overrides for the class
   * @constructor
   *
   */
  var Tracker = function (options) {
    this.init(options);
  };

  Tracker.prototype = (function () {

    // Private static scope

    var cls = Tracker;

    var defaultSettings = {
      domain: 'marketfy.com',
      trackerEndpoint: '/api/v2/store/track-session/'
    };

    var instanceCount = 0;

    /**
     * Loads a JSONP script asynchronously
     * @param {string} url URL of the script to load
     * @return {obj} DOM object for generated <script>
     */
    var loadJSONP = function (url) {
      var js = document.createElement('script');
      js.type = 'text/javascript';
      js.async = true;
      js.src = script;
      document.getElementsByTagName('head')[0].appendChild(js);
      return js;
    };

    // Public scope

    return {

      settings: defaultSettings,

      /**
       * Initialize the tracker class and start initial tracking
       * @param {options} options Settings to override
       *
       */
      init: function (options) {

        // Setup the options
        for(var key in options){
          if(options.hasOwnProperty(key)){
            this.settings[key] = options[key];
          }
        }

        this.id = ++instanceCount;
        this.requestCounter = 0;

        // Ping the session tracker
        this.ping();

      },

      /**
       * Pings the session tracking interface on Marketfy.
       * To allow for Cross Domain usage we implement JSONP which requires us
       * to create a new static method for callback on the Tracker class for
       * proper scoping.
       */
      ping: function () {

        var callbackJSONP = 'JSONP_' + this.id + '_' + this.requestCounter;
        cls[callbackJSONP] = function (ret) {
          // No callback processing needed for now
        };

        this.callback = 'MarketfyToolkit.Tracker.' + callbackJSONP;
        var requestURL = '//' + this.settings.domain + this.settings.trackerEndpoint
          + '?callback=' + this.callback + '&ref_code=' + this.settings.code;

        loadJSONP(requestURL);

        this.requestCounter++;
      }

    }
  })();

  toolkit.sessionTracker = Tracker;
  toolkit.startSession = function (options) {
    if (!toolkit.session) {
      toolkit.session = new Tracker(options);
    }
    return toolkit.session;
  }


}(window, document, MarketfyToolkit);

MarketfyToolkit.startSession();