<?php
/**
 * Copyright (c) 2012 Robin Appelman <icewind@owncloud.com>
 * This file is licensed under the Affero General Public License version 3 or
 * later.
 * See the COPYING-README file.
 */

/**
 * User authentication against an IMAP mail server
 *
 * @category Apps
 * @package  UserExternal
 * @author   Robin Appelman <icewind@owncloud.com>
 * @license  http://www.gnu.org/licenses/agpl AGPL
 * @link     http://github.com/owncloud/apps
 */
class OC_User_IMAP extends \OCA\user_external\Base {
	private $mailbox;
	private $domain;

	/**
	 * Create new IMAP authentication provider
	 *
	 * @param string $mailbox PHP imap_open mailbox definition, e.g.
	 *                        {127.0.0.1:143/imap/readonly}
	 * @param string $domain  If provided, loging will be restricted to this domain
	 */
	public function __construct($mailbox, $domain = '') {
		parent::__construct($mailbox);
		$this->mailbox=$mailbox;
		$this->domain=$domain;
	}

	/**
	 * Check if the password is correct without logging in the user
	 *
	 * @param string $uid      The username
	 * @param string $password The password
	 *
	 * @return true/false
	 */
	public function checkPassword($uid, $password) {
		if (!function_exists('imap_open')) {
			OC::$server->getLogger()->error('ERROR: PHP imap extension is not installed', ['app' => 'user_external']);
			return false;
		}

		// Replace escaped @ symbol in uid (which is a mail address)
		// but only if there is no @ symbol and if there is a %40 inside the uid
		if (!(strpos($uid, '@') !== false) && (strpos($uid, '%40') !== false)) {
			$uid = str_replace("%40","@",$uid);
		}

		if ($this->domain !== '') {
			$pieces = explode('@', $uid);
			if (count($pieces) === 1) {
				$username = $uid . '@' . $this->domain;
			} else if(count($pieces) === 2 && $pieces[1] === $this->domain) {
				$username = $uid;
				$uid = $pieces[0];
			} else {
				return false;
			}
		} else {
			$username = $uid;
 		}

		$mbox = @imap_open($this->mailbox, $username, $password, OP_HALFOPEN, 1);
		$imapErrors = imap_errors();
		$imapAlerts = imap_alerts();
		if (!empty($imapErrors)) {
			OC::$server->getLogger()->error(
				'ERROR: IMAP Error: ' . print_r($imapErrors, true),
				['app' => 'user_external']
			);
		}
		if (!empty($imapAlerts)) {
			OC::$server->getLogger()->warning(
				'WARNING: IMAP Warning: ' . print_r($imapAlerts, true),
				['app' => 'user_external']
			);
		}
		if($mbox !== false) {
			imap_close($mbox);
			$uid = mb_strtolower($uid);
			$this->storeUser($uid);
			return $uid;
		}

		return false;
	}
}