<?php
  
  /**
   * ownCloud
   *
   * @author Frank Karlitschek
   * @author Dominik Schmidt
   * @copyright 2012 Frank Karlitschek frank@owncloud.org
   * @copyright 2011 Dominik Schmidt dev@dominik-schmidt.de
   *
   * 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/>.
   *
   */
  
  /**
   * error code for functions not provided by the user backend
   */
  define('OC_USER_BACKEND_NOT_IMPLEMENTED',   -501);
  
  /**
   * actions that user backends can define
   */

  define('OC_USER_BACKEND_CREATE_USER',       0x00000001);
  define('OC_USER_BACKEND_SET_PASSWORD',      0x00000010);
  define('OC_USER_BACKEND_CHECK_PASSWORD',    0x00000100);
  define('OC_USER_BACKEND_GET_HOME',			0x00001000);
  define('OC_USER_BACKEND_GET_DISPLAYNAME',	0x00010000);
  define('OC_USER_BACKEND_SET_DISPLAYNAME',	0x00100000);
  define('OC_USER_BACKEND_PROVIDE_AVATAR',	0x01000000);
  define('OC_USER_BACKEND_COUNT_USERS',		0x10000000);
  //more actions cannot be defined without breaking 32bit platforms!

  
  /**
   * Abstract base class for user management. Provides methods for querying backend
   * capabilities.
   *
   * Subclass this for your own backends, and see OC_User_Example for descriptions
   */
  abstract class OC_User_Backend implements OC_User_Interface {
  
  	protected $possibleActions = array(
  		OC_USER_BACKEND_CREATE_USER => 'createUser',
  		OC_USER_BACKEND_SET_PASSWORD => 'setPassword',
  		OC_USER_BACKEND_CHECK_PASSWORD => 'checkPassword',
  		OC_USER_BACKEND_GET_HOME => 'getHome',
  		OC_USER_BACKEND_GET_DISPLAYNAME => 'getDisplayName',
  		OC_USER_BACKEND_SET_DISPLAYNAME => 'setDisplayName',

  		OC_USER_BACKEND_PROVIDE_AVATAR => 'canChangeAvatar',

  		OC_USER_BACKEND_COUNT_USERS => 'countUsers',

  	);
  
  	/**

  	* Get all supported actions

  	* @return int bitwise-or'ed actions

  	*
  	* Returns the supported actions as int to be
  	* compared with OC_USER_BACKEND_CREATE_USER etc.
  	*/
  	public function getSupportedActions() {
  		$actions = 0;
  		foreach($this->possibleActions AS $action => $methodName) {
  			if(method_exists($this, $methodName)) {
  				$actions |= $action;
  			}
  		}
  
  		return $actions;
  	}
  
  	/**

  	* 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($actions) {
  		return (bool)($this->getSupportedActions() & $actions);
  	}
  
  	/**

  	 * 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 a list of all users
  	* @return array an array of all uids

  	*
  	* Get a list of all users.
  	*/
  	public function getUsers($search = '', $limit = null, $offset = null) {
  		return array();
  	}
  
  	/**

  	* check if a user exists

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

  	* get the user's home directory

  	* @param string $uid the username
  	* @return boolean
  	*/
  	public function getHome($uid) {
  		return false;
  	}
  
  	/**

  	 * get display name of the user

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

  	 */
  	public function getDisplayName($uid) {
  		return $uid;
  	}
  
  	/**

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

  	 *
  	 * Get a list of all display names and user ids.
  	 */
  	public function getDisplayNames($search = '', $limit = null, $offset = null) {
  		$displayNames = array();
  		$users = $this->getUsers($search, $limit, $offset);
  		foreach ( $users as $user) {
  			$displayNames[$user] = $user;
  		}
  		return $displayNames;
  	}
  
  	/**

  	 * Check if a user list is available or not

  	 * @return boolean if users can be listed or not
  	 */
  	public function hasUserListings() {
  		return false;
  	}
  }