<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\rest;

use Yii;
use yii\base\Component;
use yii\web\UnauthorizedHttpException;

/**
 * HttpBearerAuth implements the authentication method based on HTTP Bearer token.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @since 2.0
 */
class HttpBearerAuth extends Component implements AuthInterface
{
    /**
     * @var string the HTTP authentication realm
     */
    public $realm = 'api';

    /**
     * @inheritdoc
     */
    public function authenticate($user, $request, $response)
    {
        $authHeader = $request->getHeaders()->get('Authorization');
        if ($authHeader !== null && preg_match("/^Bearer\\s+(.*?)$/", $authHeader, $matches)) {
            $identity = $user->loginByAccessToken($matches[1]);
            if ($identity !== null) {
                return $identity;
            }

            $this->handleFailure($response);
        }

        return null;
    }

    /**
     * @inheritdoc
     */
    public function handleFailure($response)
    {
        $response->getHeaders()->set('WWW-Authenticate', "Bearer realm=\"{$this->realm}\"");
        throw new UnauthorizedHttpException('You are requesting with an invalid access token.');
    }
}