--- a/lib/ga.php
+++ b/lib/ga.php
@@ -1,1 +1,187 @@
+<?php
 
+/**
+  Copyright 2009 Google Inc. All Rights Reserved.
+**/
+
+  // Tracker version.
+  define("VERSION", "4.4sh");
+
+  define("COOKIE_NAME", "__utmmobile");
+
+  // The path the cookie will be available to, edit this to use a different
+  // cookie path.
+  define("COOKIE_PATH", "/");
+
+  // Two years in seconds.
+  define("COOKIE_USER_PERSISTENCE", 63072000);
+
+  // 1x1 transparent GIF
+  $GIF_DATA = array(
+      chr(0x47), chr(0x49), chr(0x46), chr(0x38), chr(0x39), chr(0x61),
+      chr(0x01), chr(0x00), chr(0x01), chr(0x00), chr(0x80), chr(0xff),
+      chr(0x00), chr(0xff), chr(0xff), chr(0xff), chr(0x00), chr(0x00),
+      chr(0x00), chr(0x2c), chr(0x00), chr(0x00), chr(0x00), chr(0x00),
+      chr(0x01), chr(0x00), chr(0x01), chr(0x00), chr(0x00), chr(0x02),
+      chr(0x02), chr(0x44), chr(0x01), chr(0x00), chr(0x3b)
+  );
+
+  // The last octect of the IP address is removed to anonymize the user.
+  function getIP($remoteAddress) {
+    if (empty($remoteAddress)) {
+      return "";
+    }
+
+    // Capture the first three octects of the IP address and replace the forth
+    // with 0, e.g. 124.455.3.123 becomes 124.455.3.0
+    $regex = "/^([^.]+\.[^.]+\.[^.]+\.).*/";
+    if (preg_match($regex, $remoteAddress, $matches)) {
+      return $matches[1] . "0";
+    } else {
+      return "";
+    }
+  }
+
+  // Generate a visitor id for this hit.
+  // If there is a visitor id in the cookie, use that, otherwise
+  // use the guid if we have one, otherwise use a random number.
+  function getVisitorId($guid, $account, $userAgent, $cookie) {
+
+    // If there is a value in the cookie, don't change it.
+    if (!empty($cookie)) {
+      return $cookie;
+    }
+
+    $message = "";
+    if (!empty($guid)) {
+      // Create the visitor id using the guid.
+      $message = $guid . $account;
+    } else {
+      // otherwise this is a new user, create a new random id.
+      $message = $userAgent . uniqid(getRandomNumber(), true);
+    }
+
+    $md5String = md5($message);
+
+    return "0x" . substr($md5String, 0, 16);
+  }
+
+  // Get a random number string.
+  function getRandomNumber() {
+    return rand(0, 0x7fffffff);
+  }
+
+  // Writes the bytes of a 1x1 transparent gif into the response.
+  function writeGifData() {
+    global $GIF_DATA;
+    header("Content-Type: image/gif");
+    header("Cache-Control: " .
+           "private, no-cache, no-cache=Set-Cookie, proxy-revalidate");
+    header("Pragma: no-cache");
+    header("Expires: Wed, 17 Sep 1975 21:32:10 GMT");
+    echo join($GIF_DATA);
+  }
+
+  // Make a tracking request to Google Analytics from this server.
+  // Copies the headers from the original request to the new one.
+  // If request containg utmdebug parameter, exceptions encountered
+  // communicating with Google Analytics are thown.
+  function sendRequestToGoogleAnalytics($utmUrl) {
+    $options = array(
+      "http" => array(
+          "method" => "GET",
+          "user_agent" => $_SERVER["HTTP_USER_AGENT"],
+          "header" => ("Accepts-Language: " . $_SERVER["HTTP_ACCEPT_LANGUAGE"]))
+    );
+    if (!empty($_GET["utmdebug"])) {
+      $data = file_get_contents(
+          $utmUrl, false, stream_context_create($options));
+    } else {
+      $data = @file_get_contents(
+          $utmUrl, false, stream_context_create($options));
+    }
+  }
+
+  // Track a page view, updates all the cookies and campaign tracker,
+  // makes a server side request to Google Analytics and writes the transparent
+  // gif byte data to the response.
+  function trackPageView() {
+    $timeStamp = time();
+    $domainName = $_SERVER["SERVER_NAME"];
+    if (empty($domainName)) {
+      $domainName = "";
+    }
+
+    // Get the referrer from the utmr parameter, this is the referrer to the
+    // page that contains the tracking pixel, not the referrer for tracking
+    // pixel.
+    $documentReferer = $_GET["utmr"];
+    if (empty($documentReferer) && $documentReferer !== "0") {
+      $documentReferer = "-";
+    } else {
+      $documentReferer = urldecode($documentReferer);
+    }
+    $documentPath = $_GET["utmp"];
+    if (empty($documentPath)) {
+      $documentPath = "";
+    } else {
+      $documentPath = urldecode($documentPath);
+    }
+
+    $account = $_GET["utmac"];
+    $userAgent = $_SERVER["HTTP_USER_AGENT"];
+    if (empty($userAgent)) {
+      $userAgent = "";
+    }
+
+    // Try and get visitor cookie from the request.
+    $cookie = $_COOKIE[COOKIE_NAME];
+
+    $guidHeader = $_SERVER["HTTP_X_DCMGUID"];
+    if (empty($guidHeader)) {
+      $guidHeader = $_SERVER["HTTP_X_UP_SUBNO"];
+    }
+    if (empty($guidHeader)) {
+      $guidHeader = $_SERVER["HTTP_X_JPHONE_UID"];
+    }
+    if (empty($guidHeader)) {
+      $guidHeader = $_SERVER["HTTP_X_EM_UID"];
+    }
+
+    $visitorId = getVisitorId($guidHeader, $account, $userAgent, $cookie);
+
+    // Always try and add the cookie to the response.
+    setrawcookie(
+        COOKIE_NAME,
+        $visitorId,
+        $timeStamp + COOKIE_USER_PERSISTENCE,
+        COOKIE_PATH);
+
+    $utmGifLocation = "http://www.google-analytics.com/__utm.gif";
+
+    // Construct the gif hit url.
+    $utmUrl = $utmGifLocation . "?" .
+        "utmwv=" . VERSION .
+        "&utmn=" . getRandomNumber() .
+        "&utmhn=" . urlencode($domainName) .
+        "&utmr=" . urlencode($documentReferer) .
+        "&utmp=" . urlencode($documentPath) .
+        "&utmac=" . $account .
+        "&utmcc=__utma%3D999.999.999.999.999.1%3B" .
+        "&utmvid=" . $visitorId .
+        "&utmip=" . getIP($_SERVER["REMOTE_ADDR"]);
+
+    sendRequestToGoogleAnalytics($utmUrl);
+
+    // If the debug parameter is on, add a header to the response that contains
+    // the url that was used to contact Google Analytics.
+    if (!empty($_GET["utmdebug"])) {
+      header("X-GA-MOBILE-URL:" . $utmUrl);
+    }
+    // Finally write the gif data to the response.
+    writeGifData();
+  }
+?><?php
+  trackPageView();
+?>
+