Fix duplicate notification emails

apps/dav/lib/BackgroundJob/BuildReminderIndexBackgroundJob.php

@@ -8,6 +8,7 @@
  * @author Christoph Wurst <[email protected]>
  * @author Georg Ehrke <[email protected]>
  * @author Roeland Jago Douma <[email protected]>
+ * @author Richard Steinmetz <[email protected]>
  *
  * @license GNU AGPL version 3 or any later version
  *
@@ -27,6 +28,7 @@
  */
 namespace OCA\DAV\BackgroundJob;
 
+use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\CalDAV\Reminder\ReminderService;
 use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\BackgroundJob\IJobList;
@@ -55,20 +57,25 @@ class BuildReminderIndexBackgroundJob extends QueuedJob {
 	/** @var ITimeFactory */
 	private $timeFactory;
 
+	/** @var CalDavBackend */
+	private $calDavBackend;
+
 	/**
 	 * BuildReminderIndexBackgroundJob constructor.
 	 */
 	public function __construct(IDBConnection $db,
 								ReminderService $reminderService,
 								LoggerInterface $logger,
 								IJobList $jobList,
-								ITimeFactory $timeFactory) {
+								ITimeFactory $timeFactory,
+								CalDavBackend $calDavBackend) {
 		parent::__construct($timeFactory);
 		$this->db = $db;
 		$this->reminderService = $reminderService;
 		$this->logger = $logger;
 		$this->jobList = $jobList;
 		$this->timeFactory = $timeFactory;
+		$this->calDavBackend = $calDavBackend;
 	}
 
 	public function run($argument) {
@@ -105,6 +112,8 @@ private function buildIndex(int $offset, int $stopAt):int {
 			->andWhere($query->expr()->gt('id', $query->createNamedParameter($offset)))
 			->orderBy('id', 'ASC');
 
+		$calendars = [];
+
 		$stmt = $query->execute();
 		while ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
 			$offset = $row['id'];
@@ -114,7 +123,22 @@ private function buildIndex(int $offset, int $stopAt):int {
 			$row['component'] = $row['componenttype'];
 
 			try {
-				$this->reminderService->onCalendarObjectCreate($row);
+				// Fetch each calendar at most once
+				$calendarId = $row['calendarid'];
+				if (!isset($calendars[$calendarId])) {
+					$calendars[$calendarId] = $this->calDavBackend->getCalendarById($calendarId);
+				}
+
+				$calendar = $calendars[$calendarId];
+				if ($calendar === null) {
+					$this->logger->warning('Failed to fetch calendar of calendar object', [
+						'id' => $row['id'],
+						'uid' => $row['uid'],
+						'calendarid' => $calendarId
+					]);
+				} else {
+					$this->reminderService->onCalendarObjectCreate($row, $calendar);
+				}
 			} catch (\Exception $ex) {
 				$this->logger->error($ex->getMessage(), ['exception' => $ex]);
 			}

apps/dav/lib/CalDAV/Reminder/ReminderService.php

@@ -11,6 +11,7 @@
  * @author Joas Schilling <[email protected]>
  * @author Roeland Jago Douma <[email protected]>
  * @author Thomas Citharel <[email protected]>
+ * @author Richard Steinmetz <[email protected]>
  *
  * @license GNU AGPL version 3 or any later version
  *
@@ -187,10 +188,11 @@ public function processReminders() :void {
 	}
 
 	/**
-	 * @param array $objectData
+	 * @param array $objectData Calendar object data
+	 * @param array $collectionData Calendar collection data
 	 * @throws VObject\InvalidDataException
 	 */
-	public function onCalendarObjectCreate(array $objectData):void {
+	public function onCalendarObjectCreate(array $objectData, array $collectionData):void {
 		// We only support VEvents for now
 		if (strcasecmp($objectData['component'], 'vevent') !== 0) {
 			return;
@@ -215,6 +217,12 @@ public function onCalendarObjectCreate(array $objectData):void {
 			return;
 		}
 
+		$userEmail = null;
+		$user = $this->getUserFromPrincipalURI($collectionData['principaluri']);
+		if ($user) {
+			$userEmail = $user->getEMailAddress();
+		}
+
 		$uid = (string) $vevents[0]->UID;
 		$recurrenceExceptions = $this->getRecurrenceExceptionFromListOfVEvents($vevents);
 		$masterItem = $this->getMasterItemFromListOfVEvents($vevents);
@@ -237,6 +245,13 @@ public function onCalendarObjectCreate(array $objectData):void {
 					continue;
 				}
 
+				// Skip email reminders if the principal is not the organizer to prevent
+				// multiple email notifications (one per event copy).
+				if ((string) $valarm->ACTION === self::REMINDER_TYPE_EMAIL
+					&& !$this->userIsOrganizer($userEmail, $recurrenceException)) {
+					continue;
+				}
+
 				$alarms = $this->getRemindersForVAlarm($valarm, $objectData,
 					$eventHash, $alarmHash, true, true);
 				$this->writeRemindersToDatabase($alarms);
@@ -285,13 +300,22 @@ public function onCalendarObjectCreate(array $objectData):void {
 						continue;
 					}
 
-					if (!\in_array((string) $valarm->ACTION, self::REMINDER_TYPES, true)) {
+					$action = (string) $valarm->ACTION;
+					if (!\in_array($action, self::REMINDER_TYPES, true)) {
 						// Action allows x-name, we don't insert reminders
 						// into the database if they are not standard
 						$processedAlarms[] = $alarmHash;
 						continue;
 					}
 
+					// Skip email reminders if the principal is not the organizer to prevent
+					// multiple email notifications (one per event copy).
+					if ($action === self::REMINDER_TYPE_EMAIL
+						&& !$this->userIsOrganizer($userEmail, $event)) {
+						$processedAlarms[] = $alarmHash;
+						continue;
+					}
+
 					try {
 						$triggerTime = $valarm->getEffectiveTriggerTime();
 					} catch (InvalidDataException $e) {
@@ -323,16 +347,17 @@ public function onCalendarObjectCreate(array $objectData):void {
 	}
 
 	/**
-	 * @param array $objectData
+	 * @param array $objectData Calendar object data
+	 * @param array $collectionData Calendar collection data
 	 * @throws VObject\InvalidDataException
 	 */
-	public function onCalendarObjectEdit(array $objectData):void {
+	public function onCalendarObjectEdit(array $objectData, array $collectionData):void {
 		// TODO - this can be vastly improved
 		//  - get cached reminders
 		//  - ...
 
 		$this->onCalendarObjectDelete($objectData);
-		$this->onCalendarObjectCreate($objectData);
+		$this->onCalendarObjectCreate($objectData, $collectionData);
 	}
 
 	/**
@@ -808,4 +833,31 @@ private function getEffectiveRecurrenceIdOfVEvent(VEvent $vevent):int {
 	private function isRecurring(VEvent $vevent):bool {
 		return isset($vevent->RRULE) || isset($vevent->RDATE);
 	}
+
+	/**
+	 * Check whether the given email address is the organizer of an event.
+	 * Always returns true if the event has no organizer or the email address is null.
+	 *
+	 * @param string|null $userEmail
+	 * @param VEvent $vevent
+	 * @return bool
+	 */
+	private function userIsOrganizer(?string $userEmail, VEvent $vevent): bool {
+		if ($userEmail === null) {
+			// Notification won't be sent anyway if user has no email address
+			return true;
+		}
+
+		// No organizer => this is my private event (with no attendees)
+		if (!isset($vevent->ORGANIZER)) {
+			return true;
+		}
+
+		$organizerEmail = $vevent->ORGANIZER->getValue();
+		if (str_starts_with($organizerEmail, 'mailto:')) {
+			$organizerEmail = substr($organizerEmail, 7);
+		}
+
+		return $userEmail === $organizerEmail;
+	}
 }

apps/dav/lib/Listener/CalendarObjectReminderUpdaterListener.php

@@ -6,6 +6,7 @@
  * @copyright 2021 Christoph Wurst <[email protected]>
  *
  * @author Christoph Wurst <[email protected]>
+ * @author Richard Steinmetz <[email protected]>
  *
  * @license GNU AGPL version 3 or any later version
  *
@@ -106,7 +107,10 @@ public function handle(Event $event): void {
 						$event->getCalendarId(),
 						$object['uri']
 					);
-					$this->reminderService->onCalendarObjectCreate($fullObject);
+					$this->reminderService->onCalendarObjectCreate(
+						$fullObject,
+						$event->getCalendarData()
+					);
 				}
 
 				$this->logger->debug(
@@ -121,7 +125,8 @@ public function handle(Event $event): void {
 		} elseif ($event instanceof CalendarObjectCreatedEvent) {
 			try {
 				$this->reminderService->onCalendarObjectCreate(
-					$event->getObjectData()
+					$event->getObjectData(),
+					$event->getCalendarData(),
 				);
 
 				$this->logger->debug(
@@ -136,7 +141,8 @@ public function handle(Event $event): void {
 		} elseif ($event instanceof CalendarObjectUpdatedEvent) {
 			try {
 				$this->reminderService->onCalendarObjectEdit(
-					$event->getObjectData()
+					$event->getObjectData(),
+					$event->getCalendarData()
 				);
 
 				$this->logger->debug(
@@ -166,7 +172,8 @@ public function handle(Event $event): void {
 		} elseif ($event instanceof CalendarObjectRestoredEvent) {
 			try {
 				$this->reminderService->onCalendarObjectCreate(
-					$event->getObjectData()
+					$event->getObjectData(),
+					$event->getCalendarData()
 				);
 
 				$this->logger->debug(