<?php
  /**
   * Copyright (c) 2011 Jakob Sack mail@jakobsack.de
   * Copyright (c) 2012 Bart Visscher <bartv@thisnet.nl>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  class OC_Connector_Sabre_Principal implements Sabre_DAVACL_IPrincipalBackend {
  	/**
  	 * Returns a list of principals based on a prefix.
  	 *
  	 * This prefix will often contain something like 'principals'. You are only
  	 * expected to return principals that are in this base path.
  	 *
  	 * You are expected to return at least a 'uri' for every user, you can
  	 * return any additional properties if you wish so. Common properties are:
  	 *   {DAV:}displayname
  	 *
  	 * @param string $prefixPath
  	 * @return array
  	 */
  	public function getPrincipalsByPrefix( $prefixPath ) {
  		$principals = array();
  
  		if ($prefixPath == 'principals') {
  			foreach(OC_User::getUsers() as $user) {
  				$user_uri = 'principals/'.$user;
  				$principals[] = array(
  					'uri' => $user_uri,
  					'{DAV:}displayname' => $user,
  				);
  			}
  		}
  
  		return $principals;
  	}
  
  	/**
  	 * Returns a specific principal, specified by it's path.
  	 * The returned structure should be the exact same as from
  	 * getPrincipalsByPrefix.
  	 *
  	 * @param string $path
  	 * @return array
  	 */
  	public function getPrincipalByPath($path) {
  		list($prefix, $name) = explode('/', $path);
  
  		if ($prefix == 'principals' && OC_User::userExists($name)) {
  			return array(
  				'uri' => 'principals/'.$name,
  				'{DAV:}displayname' => $name,
  			);
  		}
  
  		return null;
  	}
  
  	/**
  	 * Returns the list of members for a group-principal
  	 *
  	 * @param string $principal
  	 * @return array
  	 */
  	public function getGroupMemberSet($principal) {
  		// TODO: for now the group principal has only one member, the user itself
  		$principal = $this->getPrincipalByPath($principal);
  		if (!$principal) {
  			throw new Sabre_DAV_Exception('Principal not found');
  		}
  
  		return array(
  			$principal['uri']
  		);
  	}
  
  	/**
  	 * Returns the list of groups a principal is a member of
  	 *
  	 * @param string $principal
  	 * @return array
  	 */
  	public function getGroupMembership($principal) {
  		list($prefix, $name) = Sabre_DAV_URLUtil::splitPath($principal);
  
  		$group_membership = array();
  		if ($prefix == 'principals') {
  			$principal = $this->getPrincipalByPath($principal);
  			if (!$principal) {
  				throw new Sabre_DAV_Exception('Principal not found');
  			}
  
  			// TODO: for now the user principal has only its own groups
  			return array(
  				'principals/'.$name.'/calendar-proxy-read',
  				'principals/'.$name.'/calendar-proxy-write',
  				// The addressbook groups are not supported in Sabre,
  				// see http://groups.google.com/group/sabredav-discuss/browse_thread/thread/ef2fa9759d55f8c#msg_5720afc11602e753
  				//'principals/'.$name.'/addressbook-proxy-read',
  				//'principals/'.$name.'/addressbook-proxy-write',
  			);
  		}
  		return $group_membership;
  	}
  
  	/**
  	 * Updates the list of group members for a group principal.
  	 *
  	 * The principals should be passed as a list of uri's.
  	 *
  	 * @param string $principal
  	 * @param array $members
  	 * @return void
  	 */
  	public function setGroupMemberSet($principal, array $members) {
  		throw new Sabre_DAV_Exception('Setting members of the group is not supported yet');
  	}
  
  	function updatePrincipal($path, $mutations) {
  		return 0;
  	}
  
  	function searchPrincipals($prefixPath, array $searchProperties) {
  		return array();
  	}
  }