<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Security\Core\Authorization;

use Symfony\Component\Security\Core\Authentication\AuthenticationManagerInterface;
use Symfony\Component\Security\Core\Authentication\Token\Storage\TokenStorageInterface;
use Symfony\Component\Security\Core\Exception\AuthenticationCredentialsNotFoundException;

/**
 * AuthorizationChecker is the main authorization point of the Security component.
 *
 * It gives access to the token representing the current user authentication.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 * @author Johannes M. Schmitt <schmittjoh@gmail.com>
 */
class AuthorizationChecker implements AuthorizationCheckerInterface
{
    private $tokenStorage;
    private $accessDecisionManager;
    private $authenticationManager;
    private $alwaysAuthenticate;

    /**
     * @param TokenStorageInterface          $tokenStorage
     * @param AuthenticationManagerInterface $authenticationManager An AuthenticationManager instance
     * @param AccessDecisionManagerInterface $accessDecisionManager An AccessDecisionManager instance
     * @param bool                           $alwaysAuthenticate
     */
    public function __construct(TokenStorageInterface $tokenStorage, AuthenticationManagerInterface $authenticationManager, AccessDecisionManagerInterface $accessDecisionManager, $alwaysAuthenticate = false)
    {
        $this->tokenStorage = $tokenStorage;
        $this->authenticationManager = $authenticationManager;
        $this->accessDecisionManager = $accessDecisionManager;
        $this->alwaysAuthenticate = $alwaysAuthenticate;
    }

    /**
     * {@inheritdoc}
     *
     * @throws AuthenticationCredentialsNotFoundException when the token storage has no authentication token
     */
    final public function isGranted($attributes, $subject = null)
    {
        if (null === ($token = $this->tokenStorage->getToken())) {
            throw new AuthenticationCredentialsNotFoundException('The token storage contains no authentication token. One possible reason may be that there is no firewall configured for this URL.');
        }

        if ($this->alwaysAuthenticate || !$token->isAuthenticated()) {
            $this->tokenStorage->setToken($token = $this->authenticationManager->authenticate($token));
        }

        if (!\is_array($attributes)) {
            $attributes = array($attributes);
        }

        return $this->accessDecisionManager->decide($token, $attributes, $subject);
    }
}
