<?php
  
  /**
   * ownCloud
   *
   * @author Dominik Schmidt
   * @author Artuhr Schiwon
   * @copyright 2011 Dominik Schmidt dev@dominik-schmidt.de
   * @copyright 2012 Arthur Schiwon blizzz@owncloud.com
   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either
   * version 3 of the License, or any later version.
   *
   * This library 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 along with this library.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  
  namespace OCA\user_ldap;

  use OCA\user_ldap\lib\BackendUtility;
  
  class USER_LDAP extends BackendUtility implements \OCP\UserInterface {

  	/**

  	 * checks whether the user is allowed to change his avatar in ownCloud
  	 * @param string $uid the ownCloud user name

  	 * @return boolean either the user can or cannot
  	 */
  	public function canChangeAvatar($uid) {

  		$user = $this->access->userManager->get($uid);
  		if(is_null($user)) {

  			return false;
  		}

  		if($user->getAvatarImage() === false) {

  			return true;
  		}

  
  		return false;
  	}
  
  	/**

  	 * Check if the password is correct
  	 * @param string $uid The username
  	 * @param string $password The password
  	 * @return boolean

  	 *
  	 * Check if the password is correct without logging in the user
  	 */
  	public function checkPassword($uid, $password) {

  		$uid = $this->access->escapeFilterPart($uid);

  		//find out dn of the user name

  		$filter = \OCP\Util::mb_str_replace(
  			'%uid', $uid, $this->access->connection->ldapLoginFilter, 'UTF-8');
  		$ldap_users = $this->access->fetchListOfUsers($filter, 'dn');

  		if(count($ldap_users) < 1) {
  			return false;
  		}
  		$dn = $ldap_users[0];

  		$user = $this->access->userManager->get($dn);
  		if($user->getUsername() !== false) {

  			//are the credentials OK?

  			if(!$this->access->areCredentialsValid($dn, $password)) {

  				return false;
  			}

  			$user->markLogin();

  			return $user->getUsername();

  		}
  
  		return false;
  	}
  
  	/**

  	 * Get a list of all users
  	 * @return string[] with all uids

  	 *
  	 * Get a list of all users.
  	 */
  	public function getUsers($search = '', $limit = 10, $offset = 0) {

  		$search = $this->access->escapeFilterPart($search);

  		$cachekey = 'getUsers-'.$search.'-'.$limit.'-'.$offset;
  
  		//check if users are cached, if so return

  		$ldap_users = $this->access->connection->getFromCache($cachekey);

  		if(!is_null($ldap_users)) {
  			return $ldap_users;
  		}
  
  		// if we'd pass -1 to LDAP search, we'd end up in a Protocol
  		// error. With a limit of 0, we get 0 results. So we pass null.
  		if($limit <= 0) {
  			$limit = null;
  		}

  		$filter = $this->access->combineFilterWithAnd(array(
  			$this->access->connection->ldapUserFilter,
  			$this->access->getFilterPartForUserSearch($search)

  		));
  
  		\OCP\Util::writeLog('user_ldap',
  			'getUsers: Options: search '.$search.' limit '.$limit.' offset '.$offset.' Filter: '.$filter,
  			\OCP\Util::DEBUG);
  		//do the search and translate results to owncloud names

  		$ldap_users = $this->access->fetchListOfUsers(
  			$filter,
  			array($this->access->connection->ldapUserDisplayName, 'dn'),

  			$limit, $offset);

  		$ldap_users = $this->access->ownCloudUserNames($ldap_users);

  		\OCP\Util::writeLog('user_ldap', 'getUsers: '.count($ldap_users). ' Users found', \OCP\Util::DEBUG);

  		$this->access->connection->writeToCache($cachekey, $ldap_users);

  		return $ldap_users;
  	}
  
  	/**

  	 * check if a user exists

  	 * @param string $uid the username
  	 * @return boolean
  	 */
  	public function userExists($uid) {

  		if($this->access->connection->isCached('userExists'.$uid)) {
  			return $this->access->connection->getFromCache('userExists'.$uid);

  		}

  		//getting dn, if false the user does not exist. If dn, he may be mapped only, requires more checking.

  		$user = $this->access->userManager->get($uid);
  		if(is_null($user)) {

  			\OCP\Util::writeLog('user_ldap', 'No DN found for '.$uid.' on '.
  				$this->access->connection->ldapHost, \OCP\Util::DEBUG);
  			$this->access->connection->writeToCache('userExists'.$uid, false);

  			return false;
  		}

  		$dn = $user->getDN();

  		//check if user really still exists by reading its entry

  		if(!is_array($this->access->readAttribute($dn, ''))) {

  			\OCP\Util::writeLog('user_ldap', 'LDAP says no user '.$dn.' on '.
  				$this->access->connection->ldapHost, \OCP\Util::DEBUG);

  			$this->access->connection->writeToCache('userExists'.$uid, false);

  			return false;
  		}

  		$this->access->connection->writeToCache('userExists'.$uid, true);

  		$user->update();

  		return true;
  	}
  
  	/**

  	* delete a user
  	* @param string $uid The username of the user to delete
  	* @return bool

  	*
  	* Deletes a user
  	*/
  	public function deleteUser($uid) {
  		return false;
  	}
  
  	/**

  	* get the user's home directory

  	* @param string $uid the username
  	* @return boolean
  	*/
  	public function getHome($uid) {
  		// user Exists check required as it is not done in user proxy!
  		if(!$this->userExists($uid)) {
  			return false;
  		}
  
  		$cacheKey = 'getHome'.$uid;

  		if($this->access->connection->isCached($cacheKey)) {
  			return $this->access->connection->getFromCache($cacheKey);

  		}

  		if(strpos($this->access->connection->homeFolderNamingRule, 'attr:') === 0) {
  			$attr = substr($this->access->connection->homeFolderNamingRule, strlen('attr:'));
  			$homedir = $this->access->readAttribute(
  						$this->access->username2dn($uid), $attr);

  			if($homedir && isset($homedir[0])) {
  				$path = $homedir[0];
  				//if attribute's value is an absolute path take this, otherwise append it to data dir
  				//check for / at the beginning or pattern c:\ resp. c:/
  				if(

  					'/' === $path[0]

  					|| (3 < strlen($path) && ctype_alpha($path[0])

  						&& $path[1] === ':' && ('\\' === $path[2] || '/' === $path[2]))

  				) {
  					$homedir = $path;
  				} else {
  					$homedir = \OCP\Config::getSystemValue('datadirectory',
  						\OC::$SERVERROOT.'/data' ) . '/' . $homedir[0];
  				}

  				$this->access->connection->writeToCache($cacheKey, $homedir);

  				return $homedir;
  			}
  		}
  
  		//false will apply default behaviour as defined and done by OC_User

  		$this->access->connection->writeToCache($cacheKey, false);

  		return false;
  	}
  
  	/**

  	 * get display name of the user
  	 * @param string $uid user ID of the user
  	 * @return string display name

  	 */
  	public function getDisplayName($uid) {
  		if(!$this->userExists($uid)) {
  			return false;
  		}
  
  		$cacheKey = 'getDisplayName'.$uid;

  		if(!is_null($displayName = $this->access->connection->getFromCache($cacheKey))) {

  			return $displayName;
  		}

  		$displayName = $this->access->readAttribute(
  			$this->access->username2dn($uid),
  			$this->access->connection->ldapUserDisplayName);

  
  		if($displayName && (count($displayName) > 0)) {

  			$this->access->connection->writeToCache($cacheKey, $displayName[0]);

  			return $displayName[0];
  		}
  
  		return null;
  	}
  
  	/**

  	 * Get a list of all display names
  	 * @return array with all displayNames (value) and the correspondig uids (key)

  	 *
  	 * Get a list of all display names and user ids.
  	 */
  	public function getDisplayNames($search = '', $limit = null, $offset = null) {
  		$cacheKey = 'getDisplayNames-'.$search.'-'.$limit.'-'.$offset;

  		if(!is_null($displayNames = $this->access->connection->getFromCache($cacheKey))) {

  			return $displayNames;
  		}
  
  		$displayNames = array();
  		$users = $this->getUsers($search, $limit, $offset);
  		foreach ($users as $user) {
  			$displayNames[$user] = $this->getDisplayName($user);
  		}

  		$this->access->connection->writeToCache($cacheKey, $displayNames);

  		return $displayNames;
  	}

  	/**
  	* Check if backend implements actions
  	* @param int $actions bitwise-or'ed actions
  	* @return boolean

  	*
  	* Returns the supported actions as int to be
  	* compared with OC_USER_BACKEND_CREATE_USER etc.
  	*/
  	public function implementsActions($actions) {
  		return (bool)((OC_USER_BACKEND_CHECK_PASSWORD
  			| OC_USER_BACKEND_GET_HOME

  			| OC_USER_BACKEND_GET_DISPLAYNAME

  			| OC_USER_BACKEND_PROVIDE_AVATAR
  			| OC_USER_BACKEND_COUNT_USERS)

  			& $actions);
  	}
  
  	/**
  	 * @return bool
  	 */
  	public function hasUserListings() {
  		return true;
  	}

  
  	/**
  	 * counts the users in LDAP
  	 *

  	 * @return int|bool

  	 */
  	public function countUsers() {
  		$filter = \OCP\Util::mb_str_replace(
  			'%uid', '*', $this->access->connection->ldapLoginFilter, 'UTF-8');
  		$entries = $this->access->countUsers($filter);
  		return $entries;
  	}

  }