<?php
/**
 * @author Björn Schießle <schiessle@owncloud.com>
 * @author Lukas Reschke <lukas@owncloud.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @copyright Copyright (c) 2016, ownCloud, Inc.
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OCA\DAV\Connector;

use OCP\IConfig;
use OCP\IRequest;

class PublicAuth extends \Sabre\DAV\Auth\Backend\AbstractBasic {

	/**
	 * @var \OCP\IConfig
	 */
	private $config;

	private $share;

	/**
	 * @var IRequest
	 */
	private $request;

	/**
	 * @param \OCP\IConfig $config
	 * @param IRequest $request
	 */
	public function __construct(IConfig $config,
								IRequest $request) {
		$this->config = $config;
		$this->request = $request;
	}

	/**
	 * Validates a username and password
	 *
	 * This method should return true or false depending on if login
	 * succeeded.
	 *
	 * @param string $username
	 * @param string $password
	 *
	 * @return bool
	 * @throws \Sabre\DAV\Exception\NotAuthenticated
	 */
	protected function validateUserPass($username, $password) {
		$linkItem = \OCP\Share::getShareByToken($username, false);
		\OC_User::setIncognitoMode(true);
		$this->share = $linkItem;
		if (!$linkItem) {
			return false;
		}

		if ((int)$linkItem['share_type'] === \OCP\Share::SHARE_TYPE_LINK &&
			$this->config->getAppValue('core', 'shareapi_allow_public_upload', 'yes') !== 'yes') {
			$this->share['permissions'] &= ~(\OCP\Constants::PERMISSION_CREATE | \OCP\Constants::PERMISSION_UPDATE);
		}

		// check if the share is password protected
		if (isset($linkItem['share_with'])) {
			if ($linkItem['share_type'] == \OCP\Share::SHARE_TYPE_LINK) {
				// Check Password
				$newHash = '';
				if(\OC::$server->getHasher()->verify($password, $linkItem['share_with'], $newHash)) {
					/**
					 * FIXME: Migrate old hashes to new hash format
					 * Due to the fact that there is no reasonable functionality to update the password
					 * of an existing share no migration is yet performed there.
					 * The only possibility is to update the existing share which will result in a new
					 * share ID and is a major hack.
					 *
					 * In the future the migration should be performed once there is a proper method
					 * to update the share's password. (for example `$share->updatePassword($password)`
					 *
					 * @link https://github.com/owncloud/core/issues/10671
					 */
					if(!empty($newHash)) {

					}
					return true;
				} else if (\OC::$server->getSession()->exists('public_link_authenticated')
					&& \OC::$server->getSession()->get('public_link_authenticated') === $linkItem['id']) {
					return true;
				} else {
					if (in_array('XMLHttpRequest', explode(',', $this->request->getHeader('X-Requested-With')))) {
						// do not re-authenticate over ajax, use dummy auth name to prevent browser popup
						http_response_code(401);
						header('WWW-Authenticate', 'DummyBasic real="ownCloud"');
						throw new \Sabre\DAV\Exception\NotAuthenticated('Cannot authenticate over ajax calls');
					}
					return false;
				}
			} else if ($linkItem['share_type'] == \OCP\Share::SHARE_TYPE_REMOTE) {
				return true;
			} else {
				return false;
			}
		} else {
			return true;
		}
	}

	/**
	 * @return array
	 */
	public function getShare() {
		return $this->share;
	}
}