login.php

<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');

class Login extends CI_Controller {

  public function relogin() {
    $this->load->view( 'login' );
  }

  public function not_approved() {
    $this->load->view( 'blacklist' );
  }

  public function logout() {
    $this->session->sess_destroy();
    redirect( 'login/relogin' );
  }

  public function revoke() {
    $this->session->set_userdata( 'revoke', 1 );
    redirect( 'login' );
  }

  public function index() {
    require_once APPPATH . '/libraries/google-api-php-client/src/Google_Client.php';
    require_once APPPATH . '/libraries/google-api-php-client/src/contrib/Google_Oauth2Service.php';

    $client = new Google_Client();
    $client->setClientId( 'CLIENTID' );
    $client->setClientSecret( 'SECRET' );
    $client->setDeveloperKey( 'DEVKEY' );
    $client->setRedirectUri( site_url( 'login' ) );
    $client->setScopes( array( 'openid', 'email', 'profile' ) );
    $client->setApprovalPrompt( 'auto' );
    $oauth2 = new Google_Oauth2Service($client);

    if ( $this->input->get( 'code' ) ) {
      $client->authenticate();
      $this->session->set_userdata( array( 'token' => $client->getAccessToken() ) );
      redirect( 'login' );
    }

    if ( $this->session->userdata( 'token' ) ) {
      $client->setAccessToken( $this->session->userdata( 'token' ) );
    }

    if ( $client->getAccessToken() ) {
      if ( $this->session->userdata( 'revoke' ) ) {
        $client->revokeToken();
        $this->session->sess_destroy();
        redirect( 'login/relogin' );
      }
      else {
        $token_details = json_decode( $client->getAccessToken() );
        $user = $oauth2->userinfo->get();
        $this->load->model( 'user_model', 'users' );
        $user_id = $this->users->setup_user( $user, $token_details );
        $this->session->set_userdata( array( 
          'user_id' => $user_id,
        ) );
        redirect( 'lead_approval' );
      }
    }
    else {
      $auth_url = $client->createAuthUrl();
      redirect( $auth_url );
    }
  }
}

/* End of login.php file */