4 files changed, 69 insertions, 8 deletions

diff --git a/apps/dav/lib/CalDAV/CalDavBackend.php b/apps/dav/lib/CalDAV/CalDavBackend.php
index 2bbdc51f42e..42df838523d 100644
--- a/apps/dav/lib/CalDAV/CalDavBackend.php
+++ b/apps/dav/lib/CalDAV/CalDavBackend.php
@@ -1864,6 +1864,10 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 			}
 		}
 
+		if(isset($options['uid'])) {
+			$outerQuery->andWhere($outerQuery->expr()->eq('uid', $outerQuery->createNamedParameter($options['uid'])));
+		}
+
 		if (!empty($options['types'])) {
 			$or = $outerQuery->expr()->orX();
 			foreach ($options['types'] as $type) {
diff --git a/apps/dav/lib/CalDAV/CalendarHome.php b/apps/dav/lib/CalDAV/CalendarHome.php
index ceeba31800e..cd6ae1c2f7f 100644
--- a/apps/dav/lib/CalDAV/CalendarHome.php
+++ b/apps/dav/lib/CalDAV/CalendarHome.php
@@ -206,7 +206,6 @@ class CalendarHome extends \Sabre\CalDAV\CalendarHome {
 		return $this->caldavBackend->calendarSearch($principalUri, $filters, $limit, $offset);
 	}
 
-
 	public function enableCachedSubscriptionsForThisRequest() {
 		$this->returnCachedSubscriptions = true;
 	}
diff --git a/apps/dav/lib/CalDAV/CalendarImpl.php b/apps/dav/lib/CalDAV/CalendarImpl.php
index 27a428a4075..a04e520c6bc 100644
--- a/apps/dav/lib/CalDAV/CalendarImpl.php
+++ b/apps/dav/lib/CalDAV/CalendarImpl.php
@@ -29,10 +29,19 @@ namespace OCA\DAV\CalDAV;
 
 use OCA\DAV\CalDAV\Auth\CustomPrincipalPlugin;
 use OCA\DAV\CalDAV\InvitationResponse\InvitationResponseServer;
+use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\Calendar\Exceptions\CalendarException;
 use OCP\Calendar\ICreateFromString;
 use OCP\Constants;
+use OCP\Security\ISecureRandom;
+use Psr\Log\LoggerInterface;
 use Sabre\DAV\Exception\Conflict;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Component\VEvent;
+use Sabre\VObject\Document;
+use Sabre\VObject\ITip\Message;
+use Sabre\VObject\Property\VCard\DateTime;
+use Sabre\VObject\Reader;
 use function Sabre\Uri\split as uriSplit;
 
 class CalendarImpl implements ICreateFromString {
@@ -46,13 +55,6 @@ class CalendarImpl implements ICreateFromString {
 	/** @var array */
 	private $calendarInfo;
 
-	/**
-	 * CalendarImpl constructor.
-	 *
-	 * @param Calendar $calendar
-	 * @param array $calendarInfo
-	 * @param CalDavBackend $backend
-	 */
 	public function __construct(Calendar $calendar,
 								array $calendarInfo,
 								CalDavBackend $backend) {
@@ -177,4 +179,59 @@ class CalendarImpl implements ICreateFromString {
 			fclose($stream);
 		}
 	}
+
+	/**
+	 * @throws CalendarException
+	 */
+	public function handleIMipMessage(string $name, string $calendarData): void {
+		$server = new InvitationResponseServer(false);
+
+		/** @var CustomPrincipalPlugin $plugin */
+		$plugin = $server->server->getPlugin('auth');
+		// we're working around the previous implementation
+		// that only allowed the public system principal to be used
+		// so set the custom principal here
+		$plugin->setCurrentPrincipal($this->calendar->getPrincipalURI());
+
+		if (empty($this->calendarInfo['uri'])) {
+			throw new CalendarException('Could not write to calendar as URI parameter is missing');
+		}
+		// Force calendar change URI
+		/** @var Schedule\Plugin $schedulingPlugin */
+		$schedulingPlugin = $server->server->getPlugin('caldav-schedule');
+		// Let sabre handle the rest
+		$iTipMessage = new Message();
+		/** @var VCalendar $vObject */
+		$vObject = Reader::read($calendarData);
+		/** @var VEvent $vEvent */
+		$vEvent = $vObject->{'VEVENT'};
+
+		if($vObject->{'METHOD'} === null) {
+			throw new CalendarException('No Method provided for scheduling data. Could not process message');
+		}
+
+		if(!isset($vEvent->{'ORGANIZER'}) || !isset($vEvent->{'ATTENDEE'})) {
+			throw new CalendarException('Could not process scheduling data, neccessary data missing from ICAL');
+		}
+		$orgaizer = $vEvent->{'ORGANIZER'}->getValue();
+		$attendee = $vEvent->{'ATTENDEE'}->getValue();
+
+		$iTipMessage->method = $vObject->{'METHOD'}->getValue();
+		if($iTipMessage->method === 'REPLY') {
+			if ($server->isExternalAttendee($vEvent->{'ATTENDEE'}->getValue())) {
+				$iTipMessage->recipient = $orgaizer;
+			} else {
+				$iTipMessage->recipient = $attendee;
+			}
+			$iTipMessage->sender = $attendee;
+		} else if($iTipMessage->method === 'CANCEL') {
+			$iTipMessage->recipient = $attendee;
+			$iTipMessage->sender = $orgaizer;
+		}
+		$iTipMessage->uid = isset($vEvent->{'UID'}) ? $vEvent->{'UID'}->getValue() : '';
+		$iTipMessage->component = 'VEVENT';
+		$iTipMessage->sequence = isset($vEvent->{'SEQUENCE'}) ? (int)$vEvent->{'SEQUENCE'}->getValue() : 0;
+		$iTipMessage->message = $vObject;
+		$schedulingPlugin->scheduleLocalDelivery($iTipMessage);
+	}
 }
diff --git a/apps/dav/lib/CalDAV/CalendarProvider.php b/apps/dav/lib/CalDAV/CalendarProvider.php
index f29c601db2d..5779111add3 100644
--- a/apps/dav/lib/CalDAV/CalendarProvider.php
+++ b/apps/dav/lib/CalDAV/CalendarProvider.php
@@ -26,6 +26,7 @@ declare(strict_types=1);
 namespace OCA\DAV\CalDAV;
 
 use OCP\Calendar\ICalendarProvider;
+use OCP\Calendar\ICreateFromString;
 use OCP\IConfig;
 use OCP\IL10N;
 use Psr\Log\LoggerInterface;