OAuth 2.0 google

Question

I'm trying to create an autentification with google API . I always get my page refreshed I can't get access to the user informations I see always the two alerts "here 1" and "here 2" any idea to help ?

<?php
/*  GOOGLE LOGIN BASIC - Tutorial
 *  file            - index.php
 *  Developer       - Krishna Teja G S
 *  Website         - http://packetcode.com/apps/google-login/
 *  Date            - 28th Aug 2015
 *  license         - GNU General Public License version 2 or later
*/

// REQUIREMENTS - PHP v5.3 or later
// Note: The PHP client library requires that PHP has curl extensions configured. 

/*
 * DEFINITIONS
 *
 * load the autoload file
 * define the constants client id,secret and redirect url
 * start the session
 */
require_once __DIR__.'/gplus-lib/vendor/autoload.php';

const CLIENT_ID = 'my code';
const CLIENT_SECRET = 'my code';
const REDIRECT_URI = 'http://www.servicebigdeals.com/google-login/';

session_start();






/* 
 * INITIALIZATION
 *
 * Create a google client object
 * set the id,secret and redirect uri
 * set the scope variables if required
 * create google plus object
 */
$client = new Google_Client();
$client->setClientId(CLIENT_ID);
$client->setClientSecret(CLIENT_SECRET);
$client->setRedirectUri(REDIRECT_URI);
$client->setScopes('email');

$plus = new Google_Service_Plus($client);






/*
 * PROCESS
 *
 * A. Pre-check for logout
 * B. Authentication and Access token
 * C. Retrive Data
 */

/* 
 * A. PRE-CHECK FOR LOGOUT
 * 
 * Unset the session variable in order to logout if already logged in    
 */
if (isset($_REQUEST['logout'])) {
  




   session_unset();
}

/* 
 * B. AUTHORIZATION AND ACCESS TOKEN
 *
 * If the request is a return url from the google server then
 *  1. authenticate code
 *  2. get the access token and store in session
 *  3. redirect to same url to eleminate the url varaibles sent by google
 */





if (isset($_GET['code'])) {
  $client->authenticate($_GET['code']);
  $_SESSION['access_token'] = $client->getAccessToken();
  $redirect = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['PHP_SELF'];
  header('Location: ' . filter_var($redirect, FILTER_SANITIZE_URL));
}
else {
echo "<script>alert(\"here 1 \")</script>"; 
}





/* 
 * C. RETRIVE DATA
 * 
 * If access token if available in session 
 * load it to the client object and access the required profile data
 */
if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {

 

  $client->setAccessToken($_SESSION['access_token']);
  $me = $plus->people->get('me');

  // Get User data
  $id = $me['id'];
  $name =  $me['displayName'];
  $email =  $me['emails'][0]['value'];
  $profile_image_url = $me['image']['url'];
  $cover_image_url = $me['cover']['coverPhoto']['url'];
  $profile_url = $me['url'];



} 
else {
echo "<script>alert(\"here 2 \")</script>"; 
  // get the login url   
  $authUrl = $client->createAuthUrl();
}


?>

<!-- HTML CODE with Embeded PHP-->
<div>
    <?php
    /*
     * If login url is there then display login button
     * else print the retieved data
    */
    if (isset($authUrl)) {
        echo "<a class='login' href='" . $authUrl . "'><img src='gplus-lib/signin_button.png' height='50px'/></a>";
    } else {
        print "ID: {$id} <br>";
        print "Name: {$name} <br>";
        print "Email: {$email } <br>";
        print "Image : {$profile_image_url} <br>";
        print "Cover  :{$cover_image_url} <br>";
        print "Url: {$profile_url} <br><br>";
        echo "<a class='logout' href='?logout'><button>Logout</button></a>";
    }
    ?>
</div>

</div>