OauthAuthenticator.php

<?php

namespace App\Security;

use App\Entity\Langilea;
use App\Entity\User; // your user entity
use Doctrine\ORM\EntityManagerInterface;
use KnpU\OAuth2ClientBundle\Client\ClientRegistry;
use KnpU\OAuth2ClientBundle\Security\Authenticator\OAuth2Authenticator;
use Symfony\Component\HttpFoundation\RedirectResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Generator\UrlGeneratorInterface;
use Symfony\Component\Routing\RouterInterface;
use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
use Symfony\Component\Security\Core\Exception\AuthenticationException;
use Symfony\Component\Security\Core\Exception\UserNotFoundException;
use Symfony\Component\Security\Http\Authenticator\Passport\Badge\UserBadge;
use Symfony\Component\Security\Http\Authenticator\Passport\Passport;
use Symfony\Component\Security\Http\Authenticator\Passport\SelfValidatingPassport;
use Symfony\Component\Security\Http\EntryPoint\AuthenticationEntryPointInterface;
use Symfony\Component\Security\Http\Util\TargetPathTrait;

class OauthAuthenticator  extends OAuth2Authenticator implements AuthenticationEntrypointInterface
{
    use TargetPathTrait;

    public const LOGIN_ROUTE = 'app_login';
    private ClientRegistry $clientRegistry;
    private EntityManagerInterface $entityManager;
    private RouterInterface $router;

    public function __construct(
        private readonly UrlGeneratorInterface $urlGenerator,
        ClientRegistry                         $clientRegistry,
        EntityManagerInterface                 $entityManager,
        RouterInterface                        $router)
    {
        $this->clientRegistry = $clientRegistry;
        $this->entityManager = $entityManager;
        $this->router = $router;
    }

    public function supports(Request $request): ?bool
    {
        // continue ONLY if the current ROUTE matches the check ROUTE
        return $request->attributes->get('_route') === 'oauth_check';
    }

    public function authenticate(Request $request): Passport
    {
        $client = $this->clientRegistry->getClient('generic');
        $accessToken = $this->fetchAccessToken($client);

        return new SelfValidatingPassport(
            new UserBadge($accessToken->getToken(), function() use ($accessToken, $client) {
                $user = $client->fetchUserFromToken($accessToken);

                $na = $user->getId();

                // 1) have they logged in with Facebook before? Easy!
                $existingUser = $this->entityManager->getRepository(Langilea::class)->findOneBy(['NA' => $na]);

                if ($existingUser) {
                    return $existingUser;
                }

                throw new UserNotFoundException();
            })
        );
    }

    public function onAuthenticationSuccess(Request $request, TokenInterface $token, string $firewallName): ?Response
    {
        if ($targetPath = $this->getTargetPath($request->getSession(), $firewallName)) {
            return new RedirectResponse($targetPath);
        }

        if (in_array('ROLE_ADMIN',$token->getRoleNames())) {
            return new RedirectResponse($this->urlGenerator->generate('app_admin'));
        }
        return new RedirectResponse($this->urlGenerator->generate('app_default'));
    }

    protected function getLoginUrl(Request $request): string
    {
        return $this->urlGenerator->generate(self::LOGIN_ROUTE);
    }

    public function onAuthenticationFailure(Request $request, AuthenticationException $exception): ?Response
    {
        $message = strtr($exception->getMessageKey(), $exception->getMessageData());

        return new Response($message, Response::HTTP_FORBIDDEN);
    }

    public function start(Request $request, AuthenticationException $authException = null): RedirectResponse
    {
        return new RedirectResponse(
            '/connect/', // might be the site, where users choose their oauth provider
            Response::HTTP_TEMPORARY_REDIRECT
        );
    }
}