var _ems_url              = document.location;
var _ems_tracking_image   = (_ems_url.protocol == "https:" ? "https:" : "http:") + "//www.emarsys.net/upages/ti.php";
var _ems_hash             = _ems_url.hash.substring(1);
var _ems_session_timeout  = 600; // session cookie timeout in seconds
var _ems_campaign_timeout = 30*24*3600; // campaign cookie timeout in seconds
var _ems_domain           = document.domain; // default domain to track. should be changed for 3rd party shopping cart
var _ems_never            = "Tue, 31 Dec 2030 23:59:59 GMT";
var _ems_tracking_param   = "emst"; // parameter added in redirect 

var _ems_customer         = "";
var _ems_visitor          = "";
var _ems_session          = "";
var _ems_campaign         = "";

function emsSetEnv(_ems_env) {
	_ems_tracking_image   = (_ems_url.protocol == "https:" ? "https:" : "http:") + "//"+_ems_env+".emarsys.net/upages/ti.php";
}

function emsTracking(customer, domain) {

  if(customer)
    _ems_customer = customer;

  if(domain)
    _ems_domain = domain;

  if(_ems_url.protocol == "file:")
    return;

  var _ems_date = new Date();
  
  // generate unique domain hash
  domain_hash = DJBHash(_ems_domain.substring(0,4)=="www." ? _ems_domain.substring(4,_ems_domain.length) : _ems_domain); 
  
  // get session unique id from cookie, or generate a new one
  _ems_session = _ems_getCookie("_ems_session="+domain_hash+".");
  if(_ems_session == "") {
    _ems_session  = Math.round(Math.random()*1073741824);
    
    // set session cookie
    var d = new Date(_ems_date.getTime()+(_ems_session_timeout*1000));
    document.cookie = "_ems_session="+domain_hash+"."+_ems_session+";path=/;expires="+d.toGMTString()+";";
  }

  // get visitor unique id from cookie, or use session's id
  _ems_visitor = _ems_getCookie('_ems_visitor='+domain_hash+'.');
  if(_ems_visitor == '') {
    
    _ems_visitor = _ems_session;

    // set visitor cookie
    document.cookie = "_ems_visitor="+domain_hash+"."+_ems_visitor+";path=/;";// expires="+_ems_never+";";
  }
  
  // get campaign identifier from url or from cookie
  _ems_campaign = _ems_getParam(document.location.search, _ems_tracking_param);
  if(_ems_campaign == "") {
    _ems_campaign = _ems_getCookie("_ems_campaign="+domain_hash+".");
  } else {
    // set campaign cookie
    var d = new Date(_ems_date.getTime()+(_ems_campaign_timeout*1000));
    document.cookie = "_ems_campaign="+domain_hash+"."+_ems_campaign+";path=/;expires="+d.toGMTString()+";";
  }
  
  //_ems_Tick();
}

function _ems_Tick() {
  var t = "ems_customer="+_ems_escape(_ems_customer)+
  	"&ems_visitor="+_ems_escape(_ems_visitor)+
	"&ems_session="+_ems_escape(_ems_session)+
	"&ems_campaign="+_ems_escape(_ems_campaign)+
	"&ems_page="+_ems_escape(document.location.pathname+_ems_StripParam(document.location.search, _ems_tracking_param));
  var image = new Image();
  image.src = _ems_tracking_image+"?"+t;
}

function _ems_StripParam(search, param) {
  if(search.indexOf(param+"=")>0) {
    value = _ems_getParam(search, param);

    search=search.substr(0, search.indexOf(param))+search.substr(search.indexOf(param)+param.length+value.length+2, search.length);

    if(search.substr(search.length-1,1)=="&")
      search=search.substr(0, search.length-1);
  }
  return (search == "?" ? "" : search);
}

function emsSubmitOrder() {
	// no point in sending order to emarsys if customer or user are unknown to emarsys
	if(_ems_customer == "" || _ems_campaign == "")
		return;

  ems_items=document.getElementsByName("ems_items[]"); // expecting an array, ie. <input type=hidden name="ems_items[]"> for every item
  
  var p = "ems_customer="+_ems_escape(_ems_customer)+
  	"&ems_session="+_ems_escape(_ems_session)+
	"&ems_visitor="+_ems_escape(_ems_visitor)+
	"&ems_campaign="+_ems_escape(_ems_campaign)+
	"&ems_action=purchase";

  order_fields = new Array("order", "total", "tax", "shipping", "city", "country");
  for(var i=0; i<order_fields.length; i++)
    if(eval("document.emsform."+order_fields[i]))
      p += "&"+order_fields[i]+"="+eval("document.emsform."+order_fields[i]+".value");

  item_fields = new Array("code", "category", "productname", "price", "quantity");
  for(var j=0;j<ems_items.length;j++) {
    var item_values = ems_items[j].value.split(";");
    for(var i=0; i<item_fields.length; i++)
      p += "&"+item_fields[i]+"[]="+(item_values.length>i ? item_values[i] : "");
  }
   
  var image = new Image();
  image.src = _ems_tracking_image+"?"+p;
}

function _ems_getParam(search, name) {
  if(search.charAt(0) == "?")
    search = search.substring(1, search.length);

  params = search.split("&");
  for(var i=0; i<params.length; i++) {
    param = params[i].split("=");
    if(param[0] == name)
      return param[1];
  }
  return "";
}

function _ems_getCookie(str) {
  var i = document.cookie.indexOf(str);
  if(i >= 0) {
    var start = i + str.length;
    var end = document.cookie.indexOf(";", start);
    if(end == -1) 
      end = document.cookie.length;
    return document.cookie.substring(start, end)
  }
  return '';
}

// An algorithm produced by Professor Daniel J. Bernstein and shown first to the world on the usenet newsgroup comp.lang.c. It is one of the most efficient hash functions ever published
function DJBHash(d) {
  var hash = 5381;

  for(var i=0; i<d.length; i++) {
    var c=parseInt(d.charCodeAt(i));
    hash = ((hash << 5) + hash) + c;
  }

  return (hash & 0x7FFFFFFF);
}

function _ems_escape(s) {
  return typeof(encodeURIComponent) == 'function' ? encodeURIComponent(s) : escape(s);
}