<?php

namespace OAuth2\Tests\Fixtures;

use OAuth2\OAuth2;
use OAuth2\IOAuth2GrantExtension;
use OAuth2\OAuth2ServerException;
use OAuth2\Model\IOAuth2Client;
use OAuth2\Tests\Fixtures\OAuth2StorageStub;

class OAuth2GrantExtensionStub extends OAuth2StorageStub implements IOAuth2GrantExtension
{
    protected $facebookIds = array();

    public function checkGrantExtension(IOAuth2Client $client, $uri, array $inputData, array $authHeaders)
    {
        if ('http://company.com/fb_access_token' !== $uri) {
            throw new OAuth2ServerException(OAuth2::HTTP_BAD_REQUEST, OAuth2::ERROR_UNSUPPORTED_GRANT_TYPE);
        }

        if (!isset($inputData['fb_access_token'])) {
            return false;
        }

        $fbAccessToken = $inputData['fb_access_token'];
        $fbId = $this->getFacebookIdFromFacebookAccessToken($fbAccessToken);

        return isset($this->facebookIds[$fbId]);
    }

    public function addFacebookId($id)
    {
        $this->facebookIds[$id] = $id;
    }

    /**
     * Let's assume a fb access token looks like "something_fbid"
     *
     * In real life, we would verify the access token is valid, and get the facebook_id of the
     * user via GET http://graph.facebook.com/me
     */
    protected function getFacebookIdFromFacebookAccessToken($fbAccessToken)
    {
        return substr($fbAccessToken, strpos($fbAccessToken, '_') + 1);
    }
}