<?php
  
  /**
   * ownCloud – LDAP Background Jobs
   *
   * @author Arthur Schiwon
   * @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\lib;

  class Jobs extends \OC\BackgroundJob\TimedJob {

  	static private $groupsFromDB;
  
  	static private $groupBE;
  	static private $connector;

  	public function __construct(){
  		$this->interval = self::getRefreshInterval();
  	}
  
  	public function run($argument){
  		Jobs::updateGroups();
  	}

  	static public function updateGroups() {
  		\OCP\Util::writeLog('user_ldap', 'Run background job "updateGroups"', \OCP\Util::DEBUG);

  
  		$knownGroups = array_keys(self::getKnownGroups());
  		$actualGroups = self::getGroupBE()->getGroups();
  
  		if(empty($actualGroups) && empty($knownGroups)) {
  			\OCP\Util::writeLog('user_ldap',
  				'bgJ "updateGroups" – groups do not seem to be configured properly, aborting.',
  				\OCP\Util::INFO);

  			return;
  		}
  
  		self::handleKnownGroups(array_intersect($actualGroups, $knownGroups));
  		self::handleCreatedGroups(array_diff($actualGroups, $knownGroups));
  		self::handleRemovedGroups(array_diff($knownGroups, $actualGroups));

  		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – Finished.', \OCP\Util::DEBUG);
  	}
  
  	static private function getRefreshInterval() {
  		//defaults to every hour
  		return \OCP\Config::getAppValue('user_ldap', 'bgjRefreshInterval', 3600);
  	}
  
  	static private function handleKnownGroups($groups) {
  		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – Dealing with known Groups.', \OCP\Util::DEBUG);
  		$query = \OCP\DB::prepare('
  			UPDATE `*PREFIX*ldap_group_members`
  			SET `owncloudusers` = ?
  			WHERE `owncloudname` = ?
  		');
  		foreach($groups as $group) {
  			//we assume, that self::$groupsFromDB has been retrieved already
  		    $knownUsers = unserialize(self::$groupsFromDB[$group]['owncloudusers']);
  		    $actualUsers = self::getGroupBE()->usersInGroup($group);
  		    $hasChanged = false;
  		    foreach(array_diff($knownUsers, $actualUsers) as $removedUser) {
  		        \OCP\Util::emitHook('OC_User', 'post_removeFromGroup', array('uid' => $removedUser, 'gid' => $group));
  		        \OCP\Util::writeLog('user_ldap',
  				'bgJ "updateGroups" – "'.$removedUser.'" removed from "'.$group.'".',
  				\OCP\Util::INFO);
  		        $hasChanged = true;
  		    }
  		    foreach(array_diff($actualUsers, $knownUsers) as $addedUser) {
  		        \OCP\Util::emitHook('OC_User', 'post_addToGroup', array('uid' => $addedUser, 'gid' => $group));
  		        \OCP\Util::writeLog('user_ldap',
  				'bgJ "updateGroups" – "'.$addedUser.'" added to "'.$group.'".',
  				\OCP\Util::INFO);
  		        $hasChanged = true;
  		    }
  		    if($hasChanged) {
  				$query->execute(array(serialize($actualUsers), $group));
  		    }
  		}
  		\OCP\Util::writeLog('user_ldap',
  			'bgJ "updateGroups" – FINISHED dealing with known Groups.',
  			\OCP\Util::DEBUG);
  	}
  
  	static private function handleCreatedGroups($createdGroups) {
  		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – dealing with created Groups.', \OCP\Util::DEBUG);
  		$query = \OCP\DB::prepare('
  			INSERT
  			INTO `*PREFIX*ldap_group_members` (`owncloudname`, `owncloudusers`)
  			VALUES (?, ?)
  		');
  		foreach($createdGroups as $createdGroup) {
  			\OCP\Util::writeLog('user_ldap',
  				'bgJ "updateGroups" – new group "'.$createdGroup.'" found.',
  				\OCP\Util::INFO);
  			$users = serialize(self::getGroupBE()->usersInGroup($createdGroup));
  		    $query->execute(array($createdGroup, $users));
  		}
  		\OCP\Util::writeLog('user_ldap',
  			'bgJ "updateGroups" – FINISHED dealing with created Groups.',
  			\OCP\Util::DEBUG);
  	}
  
  	static private function handleRemovedGroups($removedGroups) {
  		\OCP\Util::writeLog('user_ldap', 'bgJ "updateGroups" – dealing with removed groups.', \OCP\Util::DEBUG);
  		$query = \OCP\DB::prepare('
  			DELETE
  			FROM `*PREFIX*ldap_group_members`
  			WHERE `owncloudname` = ?
  		');
  		foreach($removedGroups as $removedGroup) {
  			\OCP\Util::writeLog('user_ldap',
  				'bgJ "updateGroups" – group "'.$removedGroup.'" was removed.',
  				\OCP\Util::INFO);
  		    $query->execute(array($removedGroup));
  		}
  		\OCP\Util::writeLog('user_ldap',
  			'bgJ "updateGroups" – FINISHED dealing with removed groups.',
  			\OCP\Util::DEBUG);
  	}
  
  	static private function getGroupBE() {
  		if(!is_null(self::$groupBE)) {
  			return self::$groupBE;
  		}
  		$configPrefixes = Helper::getServerConfigurationPrefixes(true);

  		$ldapWrapper = new LDAP();
  		if(count($configPrefixes) === 1) {

  			//avoid the proxy when there is only one LDAP server configured

  			$connector = new Connection($ldapWrapper, $configPrefixes[0]);
  			$ldapAccess = new Access($connector, $ldapWrapper);
  			self::$groupBE = new \OCA\user_ldap\GROUP_LDAP($ldapAccess);

  		} else {

  			self::$groupBE = new \OCA\user_ldap\Group_Proxy($configPrefixes, $ldapWrapper);

  		}
  
  		return self::$groupBE;
  	}
  
  	static private function getKnownGroups() {
  		if(is_array(self::$groupsFromDB)) {
  			return self::$groupsFromDB;
  		}
  		$query = \OCP\DB::prepare('
  			SELECT `owncloudname`, `owncloudusers`
  			FROM `*PREFIX*ldap_group_members`
  		');
  		$result = $query->execute()->fetchAll();
  		self::$groupsFromDB = array();
  		foreach($result as $dataset) {
  		    self::$groupsFromDB[$dataset['owncloudname']] = $dataset;
  		}
  
  		return self::$groupsFromDB;
  	}
  }