var _caq = _caq || {};
var _gcol = _gcol || {unUsedParameters: ['rootUrl'], rootUrl: _caq["rootUrl"], channel: _caq["channel"]};

_gcol.AppendPixel = function (data) {
    var instance = this;
    var url = instance.rootUrl + "__gc.gif?_=" + Math.random().toString().slice(12) + "&p=" + instance.RemoveAndEncodeParameters(data);
    var _pixel = document.createElement("img");
    _pixel.src = url;
    _pixel.id = Math.random() + "_pixel";
    _pixel.style.display = "none";
    document.body.insertBefore(_pixel, document.body.firstChild);
    document.body.removeChild(_pixel);
}

_gcol.Fire = function (event, data) {
    if (typeof event != "string") {
        throw(new Error("missing event name parameter"));
    }
    if (data) {
        data.channel = _gcol.channel;
        data["event"] = event;
        return _gcol.AppendPixel(data);
    }
}

_gcol.RemoveAndEncodeParameters = function (data) {
    var instance = this;
    var bi = instance.getBrowserInformation();
    data.ref = instance.getReferrer();
    data.os = bi.os;
    data.bv = bi.bv;
    data.bn = bi.bn;
    data.res = instance.getResolution();

    var dataToProcess = data;
    var length = instance.unUsedParameters.length;
    for (var i = 0; i < length; i++) {
        delete dataToProcess[instance.unUsedParameters[i]];
    }
    for (var i in dataToProcess) {
        if (dataToProcess[i] === null || dataToProcess[i] === undefined) {
            delete dataToProcess[i];
        }
    }
    return encodeURIComponent(_gcol.psv(dataToProcess));
}

_gcol.escape = function (value) {
    if (typeof value != 'string') return;
    return value.replace(/\|/g, "\\|");
}
_gcol.psv = function (obj) {
    var s = [];
    for (var i in obj) {
        s.push(i);
        s.push(_gcol.escape(obj[i]));
    }
    var res = s.join("||");
    return res;
}

_gcol.getResolution = function() {
     return window.screen.availWidth + "x" + window.screen.availHeight;
 }

_gcol.getReferrer = function() {
      var referrer = document.referrer;
      var host = document.location.host;
      if(referrer.indexOf(host)<0){
          return document.referrer;
      }
      return "";
  }

_gcol.getBrowserInformation = function() {
  var nVer = navigator.appVersion;
  var nAgt = navigator.userAgent;
  var browserName = navigator.appName;
  var fullVersion = '' + parseFloat(navigator.appVersion);
  var majorVersion = parseInt(navigator.appVersion, 10);
  var nameOffset, verOffset, ix;

  // In Opera, the true version is after "Opera" or after "Version"
  if ((verOffset = nAgt.indexOf("Opera")) != -1) {
      browserName = "Opera";
      fullVersion = nAgt.substring(verOffset + 6);
      if ((verOffset = nAgt.indexOf("Version")) != -1)
          fullVersion = nAgt.substring(verOffset + 8);
  }
  // In MSIE, the true version is after "MSIE" in userAgent
  else if ((verOffset = nAgt.indexOf("MSIE")) != -1) {
      browserName = "Microsoft Internet Explorer";
      fullVersion = nAgt.substring(verOffset + 5);
  }
  // In Chrome, the true version is after "Chrome"
  else if ((verOffset = nAgt.indexOf("Chrome")) != -1) {
      browserName = "Chrome";
      fullVersion = nAgt.substring(verOffset + 7);
  }
  // In Safari, the true version is after "Safari" or after "Version"
  else if ((verOffset = nAgt.indexOf("Safari")) != -1) {
      browserName = "Safari";
      fullVersion = nAgt.substring(verOffset + 7);
      if ((verOffset = nAgt.indexOf("Version")) != -1)
          fullVersion = nAgt.substring(verOffset + 8);
  }
  // In Firefox, the true version is after "Firefox"
  else if ((verOffset = nAgt.indexOf("Firefox")) != -1) {
      browserName = "Firefox";
      fullVersion = nAgt.substring(verOffset + 8);
  }
  // In most other browsers, "name/version" is at the end of userAgent
  else if ((nameOffset = nAgt.lastIndexOf(' ') + 1) <
      (verOffset = nAgt.lastIndexOf('/'))) {
      browserName = nAgt.substring(nameOffset, verOffset);
      fullVersion = nAgt.substring(verOffset + 1);
      if (browserName.toLowerCase() == browserName.toUpperCase()) {
          browserName = navigator.appName;
      }
  }
  // trim the fullVersion string at semicolon/space if present
  if ((ix = fullVersion.indexOf(";")) != -1)
      fullVersion = fullVersion.substring(0, ix);
  if ((ix = fullVersion.indexOf(" ")) != -1)
      fullVersion = fullVersion.substring(0, ix);

  majorVersion = parseInt('' + fullVersion, 10);
  if (isNaN(majorVersion)) {
      fullVersion = '' + parseFloat(navigator.appVersion);
      majorVersion = parseInt(navigator.appVersion, 10);
  }

  var OSName = "Unknown OS";
  if (navigator.appVersion.indexOf("Win") != -1) OSName = "Windows";
  if (navigator.appVersion.indexOf("Mac") != -1) OSName = "MacOS";
  if (navigator.appVersion.indexOf("X11") != -1) OSName = "UNIX";
  if (navigator.appVersion.indexOf("Linux") != -1) OSName = "Linux";

  return { "os": OSName, "bv": fullVersion, "bn": browserName };
}


if (typeof module !== 'undefined' && module.exports) {
    exports._gcol = _gcol
}