<?php
  /**
   * ownCloud - Addressbook
   *
   * @author Jakob Sack

   * @author Thomas Tanghus

   * @copyright 2011 Jakob Sack mail@jakobsack.de

   * @copyright 2012-2014 Thomas Tanghus (thomas@tanghus.net)

   *
   * 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\Contacts\CardDAV;
  
  use OCA\Contacts;

  /**
   * This class exchanges data between SabreDav and the Address book backends.
   *
   * Address book IDs are a combination of the backend name and the ID it has
   * in that backend. For your own address books it can be e.g 'local::1' for
   * an address book shared with you it could be 'shared::2' an so forth.
   */
  class Backend extends \Sabre\CardDAV\Backend\AbstractBackend {

  
  	public function __construct($backends) {
  		$this->backends = $backends;
  	}
  
  	/**
  	 * Returns the list of addressbooks for a specific user.
  	 *
  	 * @param string $principaluri
  	 * @return array
  	 */
  	public function getAddressBooksForUser($principaluri) {
  
  		$app = new Contacts\App();
  		$userAddressBooks = array();
  		foreach($this->backends as $backendName) {
  			$backend = $app->getBackend($backendName);
  			$addressBooks = $backend->getAddressBooksForUser();
  			
  			if (is_array($addressBooks)) {
  				foreach($addressBooks as $addressBook) {
  					if($addressBook['owner'] != \OCP\USER::getUser()) {
  						$addressBook['uri'] = $addressBook['uri'] . '_shared_by_' . $addressBook['owner'];
  						$addressBook['displayname'] = $addressBook['displayname'];
  					}
  					$userAddressBooks[] = array(
  						'id'  => $backend->name . '::' . $addressBook['id'],
  						'uri' => $addressBook['uri'],
  						'principaluri' => 'principals/'.$addressBook['owner'],
  						'{DAV:}displayname' => $addressBook['displayname'],

  						'{' . \Sabre\CardDAV\Plugin::NS_CARDDAV . '}addressbook-description'

  								=> $addressBook['description'],
  						'{http://calendarserver.org/ns/}getctag' => $addressBook['lastmodified'],

  						'{' . \Sabre\CardDAV\Plugin::NS_CARDDAV . '}supported-address-data' =>
  							new \Sabre\CardDAV\Property\SupportedAddressData(),

  					);
  				}
  			}
  		}
  
  		return $userAddressBooks;
  	}
  
  
  	/**
  	 * Updates an addressbook's properties
  	 *

  	 * See \Sabre\DAV\IProperties for a description of the mutations array, as

  	 * well as the return value.
  	 *
  	 * @param mixed $addressbookid
  	 * @param array $mutations

  	 * @see \Sabre\DAV\IProperties::updateProperties

  	 * @return bool|array
  	 */
  	public function updateAddressBook($addressbookid, array $mutations) {
  		$changes = array();
  
  		foreach($mutations as $property=>$newvalue) {
  			switch($property) {
  				case '{DAV:}displayname' :
  					$changes['displayname'] = $newvalue;
  					break;

  				case '{' . \Sabre\CardDAV\Plugin::NS_CARDDAV

  						. '}addressbook-description' :
  					$changes['description'] = $newvalue;
  					break;
  				default :
  					// If any unsupported values were being updated, we must
  					// let the entire request fail.
  					return false;
  			}
  		}
  
  		list($id, $backend) = $this->getBackendForAddressBook($addressbookid);
  		return $backend->updateAddressBook($id, $changes);
  
  	}
  
  	/**
  	 * Creates a new address book
  	 *
  	 * @param string $principaluri
  	 * @param string $uri Just the 'basename' of the url.
  	 * @param array $properties
  	 * @return void
  	 */
  	public function createAddressBook($principaluri, $uri, array $properties) {
  
  		foreach($properties as $property => $newvalue) {

  			switch($property) {
  				case '{DAV:}displayname' :
  					$properties['displayname'] = $newvalue;
  					break;

  				case '{' . \Sabre\CardDAV\Plugin::NS_CARDDAV

  						. '}addressbook-description' :
  					$properties['description'] = $newvalue;
  					break;
  				default :

  					throw new \Sabre\DAV\Exception\BadRequest('Unknown property: '

  						. $property);
  			}
  
  		}
  
  		$properties['uri'] = $uri;
  
  		$app = new Contacts\App();
  		$backend = $app->getBackend('local');
  
  		$backend->createAddressBook($properties);
  	}
  
  	/**
  	 * Deletes an entire addressbook and all its contents
  	 *
  	 * @param mixed $addressbookid
  	 * @return void
  	 */
  	public function deleteAddressBook($addressbookid) {
  		list($id, $backend) = $this->getBackendForAddressBook($addressbookid);
  		$backend->deleteAddressBook($id);
  	}
  
  	/**
  	 * Returns the last modified date if the backend supports it.
  	 *
  	 * @param mixed $addressbookid
  	 * @return void
  	 */
  	public function lastModifiedAddressBook($addressbookid) {
  		list($id, $backend) = $this->getBackendForAddressBook($addressbookid);
  		return $backend->lastModifiedAddressBook($id);
  	}
  
  	/**
  	 * Returns all cards for a specific addressbook id.
  	 *
  	 * @param mixed $addressbookid
  	 * @return array
  	 */
  	public function getCards($addressbookid) {
  		list($id, $backend) = $this->getBackendForAddressBook($addressbookid);
  		$contacts = $backend->getContacts($id);
  
  		$cards = array();
  		foreach($contacts as $contact) {
  			$cards[] = array(
  				'id' => $contact['id'],
  				//'carddata' => $i['carddata'],
  				'size' => strlen($contact['carddata']),
  				'etag' => '"' . md5($contact['carddata']) . '"',
  				'uri' => urlencode($contact['uri']),
  				'lastmodified' => $contact['lastmodified'] );
  		}
  
  		return $cards;
  	}
  
  	/**
  	 * Returns a specfic card
  	 *
  	 * @param mixed $addressbookid
  	 * @param string $carduri
  	 * @return array
  	 */
  	public function getCard($addressbookid, $carduri) {
  		list($id, $backend) = $this->getBackendForAddressBook($addressbookid);
  		try {
  			$contact = $backend->getContact($id, array('uri' => urldecode($carduri)));

  		} catch(\Exception $e) {

  			//throw new \Sabre\DAV\Exception\NotFound($e->getMessage());

  			\OCP\Util::writeLog('contacts', __METHOD__.', Exception: '. $e->getMessage(), \OCP\Util::DEBUG);
  			return false;
  		}

  		if(is_array($contact) ) {
  			$contact['etag'] = '"' . md5($contact['carddata']) . '"';
  			return $contact;
  		}
  		//throw new \Sabre\DAV\Exception('Error retrieving the card');

  		return false;
  	}
  
  	/**
  	 * Creates a new card
  	 *
  	 * We don't return an Etag as the carddata can have been modified
  	 * by Plugin::validate()
  	 *
  	 * @see Plugin::validate()
  	 * @param mixed $addressbookid
  	 * @param string $carduri
  	 * @param string $carddata
  	 * @return string|null
  	 */
  	public function createCard($addressbookid, $carduri, $carddata) {
  		list($id, $backend) = $this->getBackendForAddressBook($addressbookid);
  		$backend->createContact($id, $carddata, array('uri' => $carduri));
  	}
  
  	/**
  	 * Updates a card
  	 *
  	 * @param mixed $addressbookid
  	 * @param string $carduri
  	 * @param string $carddata
  	 * @return null
  	 */
  	public function updateCard($addressbookid, $carduri, $carddata) {
  		list($id, $backend) = $this->getBackendForAddressBook($addressbookid);
  		$backend->updateContact($id, array('uri' => $carduri,), $carddata);
  	}
  
  	/**
  	 * Deletes a card
  	 *
  	 * @param mixed $addressbookid
  	 * @param string $carduri
  	 * @return bool
  	 */
  	public function deleteCard($addressbookid, $carduri) {
  		list($id, $backend) = $this->getBackendForAddressBook($addressbookid);
  		return $backend->deleteContact($id, array('uri' => $carduri));
  	}
  
  	/**
  	 * @brief gets the userid from a principal path
  	 * @param string $principaluri
  	 * @return string
  	 */
  	public function userIDByPrincipal($principaluri) {

  		list(, $userid) = \Sabre\DAV\URLUtil::splitPath($principaluri);

  		return $userid;
  	}
  
  	/**
  	 * Get the backend for an address book
  	 *
  	 * @param mixed $addressbookid
  	 * @return array(string, \OCA\Contacts\Backend\AbstractBackend)
  	 */
  	public function getBackendForAddressBook($addressbookid) {
  		list($backendName, $id) = explode('::', $addressbookid);
  		$app = new Contacts\App();
  		$backend = $app->getBackend($backendName);
  		if($backend->name === $backendName && $backend->hasAddressBook($id)) {
  			return array($id, $backend);
  		}

  		throw new \Sabre\DAV\Exception\NotFound('Backend not found: ' . $addressbookid);

  	}
  }