<?php
/**
* CalDAV sync for the Calendar plugin
*
* @version @package_version@
* @author Daniel Morlock <daniel.morlock@awesome-it.de>
*
* Copyright (C) Awesome IT GbR <info@awesome-it.de>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program 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 program. If not, see <http://www.gnu.org/licenses/>.
*/
require_once (dirname(__FILE__).'/../../lib/caldav-client.php');
class caldav_sync
{
const ACTION_NONE = 1;
const ACTION_UPDATE = 2;
const ACTION_CREATE = 4;
private $cal_id = null;
private $ctag = null;
private $url = null;
/**
* Default constructor for calendar synchronization adapter.
*
* @param array Hash array with caldav properties at least the following:
* id: Calendar ID
* caldav_url: Caldav calendar URL.
* caldav_user: Caldav http basic auth user.
* caldav_pass: Password für caldav user.
* caldav_tag: Caldav ctag for calendar.
*/
public function __construct($cal)
{
$this->cal_id = $cal["id"];
$this->url = $cal["caldav_url"];
$this->ctag = isset($cal["caldav_tag"]) ? $cal["caldav_tag"] : null;
// CalDAV client auth
$username = isset($cal["caldav_user"]) ? $cal["caldav_user"] : null;
$pass = isset($cal["caldav_pass"]) ? $cal["caldav_pass"] : null;
$this->caldav = new caldav_client($this->url, $username, $pass, $cal["ssl_verify"] ?? false );
}
/**
* Getter for current calendar ctag.
* @return string
*/
public function get_ctag()
{
return $this->ctag;
}
/**
* Determines whether current calendar needs to be synced
* regarding the CalDAV ctag.
*
* @return True if the current calendar ctag differs from the CalDAV tag which
* indicates that there are changes that must be synched. Returns false
* if the calendar is up to date, no sync necesarry.
*/
public function is_synced()
{
$is_synced = $this->ctag == $this->caldav->get_ctag() && $this->ctag;
caldav_driver::debug_log("Ctag indicates that calendar \"$this->cal_id\" ".($is_synced ? "is synced." : "needs update!"));
return $is_synced;
}
/**
* Synchronizes given events with caldav server and returns updates.
*
* @param array List of hash arrays with event properties, must include "caldav_url" and "tag".
* @return array Tuple containing the following lists:
*
* Caldav properties for events to be created or to be updated with the keys:
* url: Event ical URL relative to calendar URL
* etag: Remote etag of the event
* local_event: The local event in case of an update.
* remote_event: The current event retrieved from caldav server.
*
* A list of event ids that are in sync.
*/
public function get_updates($events)
{
$ctag = $this->caldav->get_ctag();
// Horde calendar will 404 on PROPFIND when trying to get CTAGS. As such, you can't check them, as we can't have nice things. ;_;
#if($ctag)
#{
$this->ctag = $ctag;
$etags = $this->caldav->get_etags();
list($updates, $synced_uids) = $this->_get_event_updates($events, $etags);
return array($this->_get_event_data($updates), $synced_uids);
#}
#else
#{
# caldav_driver::debug_log("Unkown error while fetching calendar ctag for calendar \"$this->cal_id\"!");
#}
#return null;
}
/**
* Determines sync status and requried updates for the given events using given list of etags.
*
* @param array List of hash arrays with event properties, must include "caldav_url" and "caldav_tag".
* @param array List of current remote etags.
* @return array Tuple containing the following lists:
*
* Caldav properties for events to be created or to be updated with the keys:
* url: Event ical URL relative to calendar URL
* etag: Remote etag of the event
* local_event: The local event in case of an update.
*
* A list of event ids that are in sync.
*/
private function _get_event_updates($events, $etags)
{
$updates = array();
$in_sync = array();
foreach ($etags as $etag)
{
$url = $etag["url"];
$etag = $etag["etag"];
$event_found = false;
foreach($events as $event)
{
$caldav_url = str_replace("//", "/", $event["caldav_url"]);
if ($caldav_url == $url)
{
$event_found = true;
if ($event["caldav_tag"] != $etag)
{
caldav_driver::debug_log("Event ".$event["uid"]." needs update.");
array_push($updates, array(
"local_event" => $event,
"etag" => $etag,
"url" => $url
));
}
else
{
array_push($in_sync, $event["uid"]);
}
}
}
if (!$event_found)
{
caldav_driver::debug_log("Found new event ".$url);
array_push($updates, array(
"url" => $url,
"etag" => $etag
));
}
}
return array($updates, $in_sync);
}
/**
* Fetches event data and attaches it to the given update properties.
*
* @param $updates List of update properties.
* @return array List of update properties with additional key "remote_event" containing the current caldav event.
*/
private function _get_event_data($updates)
{
$urls = array();
foreach ($updates as $update)
{
array_push($urls, $update["url"]);
}
$events = $this->caldav->get_events($urls);
foreach($updates as &$update)
{
// Attach remote events to the appropriate updates.
// Note that this assumes unique event URL's!
$url = $update["url"];
if(array_key_exists($url, $events) && $events[$url]) {
$update["remote_event"] = $events[$url];
$update["remote_event"]["calendar"] = $this->cal_id;
}
}
return $updates;
}
/**
* Creates the given event on the CalDAV server.
*
* @param array Hash array with event properties.
* @return Event with updated "caldav_url" and "caldav_tag" attributes, false on error.
*/
public function create_event($event)
{
$props = array(
"caldav_url" => parse_url($this->url, PHP_URL_PATH)."/".$event["uid"].".ics",
"caldav_tag" => null
);
caldav_driver::debug_log("Push new event to url ".$props["caldav_url"]);
$result = $this->caldav->put_event($props["caldav_url"], $event);
if($result == false || $result < 0) return false;
return array_merge($event, $props);
}
/**
* Updates the given event on the CalDAV server.
*
* @param array Hash array with event properties to update, must include "uid", "caldav_url" and "caldav_tag".
* @return True on success, false on error, -1 if the given event/etag is not up to date.
*/
public function update_event($event)
{
caldav_driver::debug_log("Updating event uid \"".$event["uid"]."\".");
return $this->caldav->put_event($event["caldav_url"], $event, $event["caldav_tag"]);
}
/**
* Removes the given event from the caldav server.
*
* @param array Hash array with events properties, must include "caldav_url".
* @return True on success, false on error.
*/
public function remove_event($event)
{
caldav_driver::debug_log("Removing event uid \"".$event["uid"]."\".");
return $this->caldav->remove_event($event["caldav_url"]);
}
};
?>