"google/apiclient": "^2.0"

'Google' =>
[
        'googleClientID' => '123456.apps.googleusercontent.com',
        'googleClientSecret' => 'abcdefghi',
        'googleRedirectUrl' => 'http://example.com/oauth2callback'
    ]

$routes->connect('/oauth2callback', ['controller' => 'Account', 'action' => 'confirmlogin'], ['_name' => 'account-google-redirect-url']);

/**
 * Gmail login method
 */

    public function googlelogin()
    {


$client = new Google_Client();
    $client->setClientId(Configure::read('Google.googleClientID'));
    $client->setClientSecret(Configure::read('Google.googleClientSecret'));
    $client->setRedirectUri(Configure::read('Google.googleRedirectUrl'));
    $client->se

tScopes([
            "https://www.googleapis.com/auth/userinfo.profile",
            'https://www.googleapis.com/auth/userinfo.email'
        ]);
        $url = $client->createAuthUrl();
        $this->redirect($url);
    }

public function confirmlogin()
    {
        $client = new Google_Client();
        $client->setClientId(Configure::read('Google.googleClientID'));
        $client->setClientSecret(Configure::read('Google.googleClientSecret'));
        $client->setRedirectUri(Configure::read('Google.googleRedirectUrl'));
        $client->setScopes([
            "https://www.googleapis.com/auth/userinfo.profile",
            'https://www.googleapis.com/auth/userinfo.email'
        ]);
        $client->setApprovalPrompt('auto');
        $usersTable = TableRegistry::get('Users');
        if (isset($this->request->query['code'])) {
            $client->authenticate($this->request->query['code']);
            $this->request->Session()->write('access_token', $client->getAccessToken());
        }
        if ($this->request->Session()->check('access_token') && ($this->request->Session()->read('access_token'))) {
            $client->setAccessToken($this->request->Session()->read('access_token'));
        }
        if ($client->getAccessToken()) {
            $this->request->Session()->write('access_token', $client->getAccessToken());
            $oauth2 = new Google_Service_Oauth2($client);
            $user = $oauth2->userinfo->get();
            try {
                if (!empty($user)) {
                    if ((preg_match("/(@example.com)$/", $user['email'])) || (preg_match("/(@example.in)$/", $user['email']))) {
                        $result = $usersTable->find('all')
                                ->where(['email' => $user['email']])
                                ->first();
                        if (!empty($result)) {
                            $this->AccessControl->setUser($result->toArray(), false);
                            $this->Flash->set(__('You have successfuly logged in.'), ['element' => 'success']);
                            $this->redirect(['_name' => 'dashboard']);
                        } else {
                            $data = [];
                            $data['email'] = $user['email'];
                            $data['first_name'] = $user['givenName'];
                            $data['last_name'] = $user['familyName'];
                            $data['socialId'] = $user['id'];
                            $data['role_id'] = Configure::read('Role.loginWithGmailUserRole');
                            //$data matches my Users table
                            $entity = $usersTable->newEntity($data);
                            if ($usersTable->save($entity)) {
                                $data['id'] = $entity->id;
                                $this->AccessControl->setUser($data, false);
                                $this->Flash->set(__('You have successfuly logged in.'), ['element' => 'success']);
                                $this->redirect(['_name' => 'dashboard']);
                            } else {
                                $this->Flash->error(__('Invalid login.'));
            //redirect to login action
                                $this->redirect(['_name' => 'account-login']);
                            }
                        }
                    } else {
                        $this->Flash->error(__('Your email is invalid for this application.'));
        //redirect to login action
                        $this->redirect(['_name' => 'account-login']);
                    }
                } else {
                    $this->Flash->error(__('Gmail infos not found.'));
        //redirect to login action
                    return $this->redirect(['_name' => 'account-login']);
                }
            } catch (Exception $e) {
                $this->Flash->error(__('Gmail error.'));
                return $this->redirect(['_name' => 'account-login']);
            }
        }
    }