Tích hợp đăng nhập Google vào Website

CREATE TABLE IF NOT EXISTS `google_users` (
  `google_id` decimal(21,0) NOT NULL,
  `google_name` varchar(60) NOT NULL,
  `google_email` varchar(60) NOT NULL,
  `google_link` varchar(60) NOT NULL,
  `google_picture_link` varchar(200) NOT NULL,
  PRIMARY KEY (`google_id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

{
	"require": {
	  "google/apiclient": "1.0.*@beta"
	}
}

<?php

require_once '/vendor/autoload.php';

// Lấy những giá trị này từ https://console.google.com
$client_id = '81678134426-j16al8im2mbsetfse3dv43svgvcs3cr8.apps.googleusercontent.com'; 
$client_secret="6d69gLy991-1H-mxDnUQD8dg";
$redirect_uri = 'https://phpbbvietnam.com.app/google_api/login/login.php';

//Thông tin kết nói database
$db_username = "root"; //Database Username
$db_password = ""; //Database Password
$host_name = "localhost"; //Mysql Hostname
$db_name="free_tuts"; //Database Name
###################################################################

$client = new Google_Client();
$client->setClientId($client_id);
$client->setClientSecret($client_secret);
$client->setRedirectUri($redirect_uri);
$client->addScope("email");
$client->addScope("profile");

$service = new Google_Service_Oauth2($client);

// Nếu kết nối thành công, sau đó xử lý thông tin và lưu vào database
if (isset($_GET['code'])) {
  	$client->authenticate($_GET['code']);
 	$_SESSION['access_token'] = $client->getAccessToken();
  	//header('Location: ' . filter_var($redirect_uri, FILTER_SANITIZE_URL));
  	$user = $service->userinfo->get(); //get user info 

   	// connect to database
	$mysqli = new mysqli($host_name, $db_username, $db_password, $db_name);
	if ($mysqli->connect_error) {
	    die('Error : ('. $mysqli->connect_errno .') '. $mysqli->connect_error);
	}

	//Kiểm tra xem nếu user này đã tồn tại, sau đó nên login tự động
	$result = $mysqli->query("SELECT COUNT(google_id) as usercount FROM google_users WHERE google_id=$user->id");
	$user_count = $result->fetch_object()->usercount; //will return 0 if user doesn't exist

	//show user picture
	echo '<img src="'.$user->picture.'" style="float: right;margin-top: 33px;" />';

	if($user_count) // Nếu user tồn tại thì show thông tin hiện có
	{
	    echo 'Welcome back '.$user->name.'! [<a href="'.$redirect_uri.'?logout=1">Log Out</a>]';
	}
	else //Ngược lại tạo mới 1 user vào database
	{ 
	    echo 'Hi '.$user->name.', Thanks for Registering! [<a href="'.$redirect_uri.'?logout=1">Log Out</a>]';
	    $statement = $mysqli->prepare("INSERT INTO google_users (google_id, google_name, google_email, google_link, google_picture_link) VALUES (?,?,?,?,?)");
	    $statement->bind_param('issss', $user->id,  $user->name, $user->email, $user->link, $user->picture);
	    $statement->execute();
	    echo $mysqli->error;
	}
  	exit;
}

//Nếu sẵn sàng kết nối, sau đó lưu session với tên access_token
if (isset($_SESSION['access_token']) && $_SESSION['access_token']) {
 	$client->setAccessToken($_SESSION['access_token']);
} else { // Ngược lại tạo 1 link để login
 	$authUrl = $client->createAuthUrl();
}

//Hiển thị button để login
echo '<div style="margin:20px">';
if (isset($authUrl)){ 
    //show login url
    echo '<div align="center">';
    echo '<h3>Login with Google -- Demo</h3>';
    echo '<div>Please click login button to connect to Google.</div>';
    echo '<a class="login" href="' . $authUrl . '">LOGIN</a>';
    echo '</div>';
    
} 
echo '</div>';