FacebookController.php

<?php

namespace App\Http\Controllers\Auth;

use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use App\Models\User;
use Illuminate\Support\Facades\Validator;
use Illuminate\Support\Facades\Auth;
use SammyK\LaravelFacebookSdk\LaravelFacebookSdk;

class FacebookController extends Controller
{
	/**
	 * Check user exists
	 * 
	 * @var bool
	 */
	protected $userExists = false;

	/**
	 * Create a new user instance after a valid registration.
	 *
	 * @param array $data
	 * @param $token
	 *
	 * @return static
	 */
	protected function createOrUpdate(array $data, $token)
	{
		$user = User::firstOrNew(['email' => $data['email']]);
		$user->access_token = (string) $token;
		$this->userExists = $user->exists;

		if(!$user->exists){
			$user->facebook_user_id = $data['id'];
			$user->email = $data['email'];
			$user->name = $data['name'];
		}

		$user->save();

		return $user;
	}

	/**
	 * Authenticate the user
	 *
	 * @param $user
	 *
	 * @return mixed
	 */
	protected function authenticate($user)
	{
		return Auth::login($user);
	}

	/**
	 * Go back with _error message
	 * 
	 * @param $message
	 *
	 * @return \Illuminate\Http\RedirectResponse
	 */
	protected function errorBack($message)
	{
		return redirect()->back()->with('_error', $message);
	}

	/**
	 * Return $graphUser format
	 * 
	 * @param $graphUser
	 *
	 * @return array
	 */
	protected function formatGraphUser($graphUser)
	{
		return [
			'name' => $graphUser['name'],
			'email' => $graphUser['email'],
			'id' => $graphUser['id']
		];
	}

	/**
	 * Register user
	 * 
	 * @param LaravelFacebookSdk $facebookSdk
	 *
	 * @return \Illuminate\Http\RedirectResponse
	 */
	public function register(LaravelFacebookSdk $facebookSdk)
	{
		if(Auth::check()){
			return redirect()->route('welcome.index');
		}

		try {
			$token = $facebookSdk->getAccessTokenFromRedirect();
		} catch (Facebook\Exceptions\FacebookSDKException $e) {
			return $this->errorBack('Ocorreu um erro, tente novamente ou se cadastre manualmente.');
		}

		if(!$token){
			return $this->errorBack('Erro ao obter token, tente novamente ou se cadastre manualmente.');
		}

		if(!$token->isLongLived()){
			$oauth_client = $facebookSdk->getOAuth2Client();

			try {
				$token = $oauth_client->getLongLivedAccessToken($token);
			} catch (Facebook\Exceptions\FacebookSDKException $e) {
				return $this->errorBack('Erro ao estender o token.');
			}
		}

		$facebookSdk->setDefaultAccessToken($token);
		session(['user_facebook_access_token' => (string) $token]);

		try {
			$response = $facebookSdk->get('/me?fields=id,name,email');
		} catch (Facebook\Exceptions\FacebookSDKException $e) {
			return $this->errorBack('Erro ao obter suas informações');
		}

		$graphUser = $this->formatGraphUser($response->getGraphUser());
		$this->authenticate($this->createOrUpdate($graphUser, $token));

		if(!$this->userExists)
			return redirect()->route('welcome.index')->with('_success', 'Seja Bem-Vindo ao Sherlock!');

		return redirect()->route('welcome.index');
	}
}