<?php defined('SYSPATH') or die('No direct access allowed.');
// Facebook API версия 1.0 (22.04.2015)

session_start();
require_once 'autoload.php';

use Facebook\FacebookSession;
use Facebook\FacebookRedirectLoginHelper;
use Facebook\FacebookRequest;
use Facebook\FacebookResponse;
use Facebook\FacebookSDKException;
use Facebook\FacebookRequestException;
use Facebook\FacebookAuthorizationException;
use Facebook\GraphObject;
use Facebook\Entities\AccessToken;
use Facebook\HttpClients\FacebookCurlHttpClient;
use Facebook\HttpClients\FacebookHttpable;

class Facebook {


	public static function get_user_id()
	{
		$user_id = 0;
		session_start();
		FacebookSession::setDefaultApplication( 'ххх','ууу' );
		$helper = new FacebookCanvasLoginHelper();

		try {
			$session = $helper->getSession();

		}catch(FacebookRequestException $ex) {
			// When Facebook returns an error


		} catch(\Exception $ex) {
			// When validation fails or other local issues
		}
		if (!is_null($session)) {
			// Logged in

			try {

				//Get user name
				$user_profile = (new FacebookRequest(
					$session, 'GET', '/me'
				))->execute()->getGraphObject(GraphUser::className());

				$user_id = $user_profile->getId();

			} catch(FacebookRequestException $e) {
				// When Facebook returns an error

			} catch(Exception $e) {
				// When validation fails or other local issues
			}
		}


		return $user_id;
	}


}

$client_id = 'ххх'; // Client ID
client_secret = 'ууу'; // Client secret
$params = array(
			'client_id'     => $client_id,
			'client_secret' => $client_secret,
			'grant_type' => 'client_credentials'
);
$url = 'https://graph.facebook.com/oauth/access_token';
$tokenInfo = null;
parse_str(file_get_contents($url . '?' . http_build_query($params)), $tokenInfo);
die($tokenInfo['access_token']);