$httpClient = new \SocialConnect\Common\Http\Client\Curl();

/**
 * By default we are using Curl class from SocialConnect/Common
 * but you can use Guzzle wrapper ^5.3|^6.0
 */
//$httpClient = new \SocialConnect\Common\Http\Client\Guzzle(
//    new \GuzzleHttp\Client()
//);

/**
 * Why do we need cache decorator for HTTP Client?
 * Providers like OpenID & OpenIDConnect require US
 * to request OpenID specification (and JWK(s) for OpenIDConnect)
 *
 * It's not a best practice to request it every time, because it's unneeded round trip to the server
 * if you are using OpenID or OpenIDConnect we suggest you to use cache
 *
 * If you don`t use providers like (Steam) from OpenID or OpenIDConnect
 * you may skip this because it's not needed
 */
$httpClient = new \SocialConnect\Common\Http\Client\Cache(
    $httpClient,
    /**
     * Please dont use FilesystemCache for production/stage env, only for local testing!
     * It doesnot support cache expire (remove)
     */
    new \Doctrine\Common\Cache\FilesystemCache(
        __DIR__ . '/cache'
    )
);

$configureProviders = [
    'redirectUri' => 'http://sconnect.local/auth/cb/${provider}/',
    'provider' => [
        'facebook' => [
            'applicationId' => '',
            'applicationSecret' => '',
            'scope' => ['email'],
            'options' => [
                'identity.fields' => [
                    'email',
                    'picture.width(99999)'
                ],
            ],
        ],
    ],
];

$service = new \SocialConnect\Auth\Service(
    $httpClient,
    new \SocialConnect\Provider\Session\Session(),
    $configureProviders
);

/**
 * By default collection factory is null, in this case Auth\Service will create 
 * a new instance of \SocialConnect\Auth\CollectionFactory
 * you can use custom or register another providers by CollectionFactory instance
 */
$collectionFactory = null;

$service = new \SocialConnect\Auth\Service(
    $httpClient,
    new \SocialConnect\Provider\Session\Session(),
    $configureProviders,
    $collectionFactory
);

$providerName = 'facebook';

$provider = $service->getProvider($providerName);
header('Location: ' . $provider->makeAuthUrl());

$providerName = 'facebook';

$provider = $service->getProvider($providerName);
$accessToken = $provider->getAccessTokenByRequestParameters($_GET);
var_dump($accessToken);

$user = $provider->getIdentity($accessToken);
var_dump($user);