migrate therinaldos.com data

wedding-pics/apps/dav/lib/CalDAV/Reminder/Backend.php

@@ -0,0 +1,222 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Thomas Citharel
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IDBConnection;
+
+/**
+ * Class Backend
+ *
+ * @package OCA\DAV\CalDAV\Reminder
+ */
+class Backend {
+
+	/** @var IDBConnection */
+	protected $db;
+
+	/** @var ITimeFactory */
+	private $timeFactory;
+
+	/**
+	 * Backend constructor.
+	 *
+	 * @param IDBConnection $db
+	 * @param ITimeFactory $timeFactory
+	 */
+	public function __construct(IDBConnection $db,
+		ITimeFactory $timeFactory) {
+		$this->db = $db;
+		$this->timeFactory = $timeFactory;
+	}
+
+	/**
+	 * Get all reminders with a notification date before now
+	 *
+	 * @return array
+	 * @throws \Exception
+	 */
+	public function getRemindersToProcess():array {
+		$query = $this->db->getQueryBuilder();
+		$query->select(['cr.*', 'co.calendardata', 'c.displayname', 'c.principaluri'])
+			->from('calendar_reminders', 'cr')
+			->where($query->expr()->lte('cr.notification_date', $query->createNamedParameter($this->timeFactory->getTime())))
+			->join('cr', 'calendarobjects', 'co', $query->expr()->eq('cr.object_id', 'co.id'))
+			->join('cr', 'calendars', 'c', $query->expr()->eq('cr.calendar_id', 'c.id'));
+		$stmt = $query->execute();
+
+		return array_map(
+			[$this, 'fixRowTyping'],
+			$stmt->fetchAll()
+		);
+	}
+
+	/**
+	 * Get all scheduled reminders for an event
+	 *
+	 * @param int $objectId
+	 * @return array
+	 */
+	public function getAllScheduledRemindersForEvent(int $objectId):array {
+		$query = $this->db->getQueryBuilder();
+		$query->select('*')
+			->from('calendar_reminders')
+			->where($query->expr()->eq('object_id', $query->createNamedParameter($objectId)));
+		$stmt = $query->execute();
+
+		return array_map(
+			[$this, 'fixRowTyping'],
+			$stmt->fetchAll()
+		);
+	}
+
+	/**
+	 * Insert a new reminder into the database
+	 *
+	 * @param int $calendarId
+	 * @param int $objectId
+	 * @param string $uid
+	 * @param bool $isRecurring
+	 * @param int $recurrenceId
+	 * @param bool $isRecurrenceException
+	 * @param string $eventHash
+	 * @param string $alarmHash
+	 * @param string $type
+	 * @param bool $isRelative
+	 * @param int $notificationDate
+	 * @param bool $isRepeatBased
+	 * @return int The insert id
+	 */
+	public function insertReminder(int $calendarId,
+		int $objectId,
+		string $uid,
+		bool $isRecurring,
+		int $recurrenceId,
+		bool $isRecurrenceException,
+		string $eventHash,
+		string $alarmHash,
+		string $type,
+		bool $isRelative,
+		int $notificationDate,
+		bool $isRepeatBased):int {
+		$query = $this->db->getQueryBuilder();
+		$query->insert('calendar_reminders')
+			->values([
+				'calendar_id' => $query->createNamedParameter($calendarId),
+				'object_id' => $query->createNamedParameter($objectId),
+				'uid' => $query->createNamedParameter($uid),
+				'is_recurring' => $query->createNamedParameter($isRecurring ? 1 : 0),
+				'recurrence_id' => $query->createNamedParameter($recurrenceId),
+				'is_recurrence_exception' => $query->createNamedParameter($isRecurrenceException ? 1 : 0),
+				'event_hash' => $query->createNamedParameter($eventHash),
+				'alarm_hash' => $query->createNamedParameter($alarmHash),
+				'type' => $query->createNamedParameter($type),
+				'is_relative' => $query->createNamedParameter($isRelative ? 1 : 0),
+				'notification_date' => $query->createNamedParameter($notificationDate),
+				'is_repeat_based' => $query->createNamedParameter($isRepeatBased ? 1 : 0),
+			])
+			->execute();
+
+		return $query->getLastInsertId();
+	}
+
+	/**
+	 * Sets a new notificationDate on an existing reminder
+	 *
+	 * @param int $reminderId
+	 * @param int $newNotificationDate
+	 */
+	public function updateReminder(int $reminderId,
+		int $newNotificationDate):void {
+		$query = $this->db->getQueryBuilder();
+		$query->update('calendar_reminders')
+			->set('notification_date', $query->createNamedParameter($newNotificationDate))
+			->where($query->expr()->eq('id', $query->createNamedParameter($reminderId)))
+			->execute();
+	}
+
+	/**
+	 * Remove a reminder by it's id
+	 *
+	 * @param integer $reminderId
+	 * @return void
+	 */
+	public function removeReminder(int $reminderId):void {
+		$query = $this->db->getQueryBuilder();
+
+		$query->delete('calendar_reminders')
+			->where($query->expr()->eq('id', $query->createNamedParameter($reminderId)))
+			->execute();
+	}
+
+	/**
+	 * Cleans reminders in database
+	 *
+	 * @param int $objectId
+	 */
+	public function cleanRemindersForEvent(int $objectId):void {
+		$query = $this->db->getQueryBuilder();
+
+		$query->delete('calendar_reminders')
+			->where($query->expr()->eq('object_id', $query->createNamedParameter($objectId)))
+			->execute();
+	}
+
+	/**
+	 * Remove all reminders for a calendar
+	 *
+	 * @param int $calendarId
+	 * @return void
+	 */
+	public function cleanRemindersForCalendar(int $calendarId):void {
+		$query = $this->db->getQueryBuilder();
+
+		$query->delete('calendar_reminders')
+			->where($query->expr()->eq('calendar_id', $query->createNamedParameter($calendarId)))
+			->execute();
+	}
+
+	/**
+	 * @param array $row
+	 * @return array
+	 */
+	private function fixRowTyping(array $row): array {
+		$row['id'] = (int) $row['id'];
+		$row['calendar_id'] = (int) $row['calendar_id'];
+		$row['object_id'] = (int) $row['object_id'];
+		$row['is_recurring'] = (bool) $row['is_recurring'];
+		$row['recurrence_id'] = (int) $row['recurrence_id'];
+		$row['is_recurrence_exception'] = (bool) $row['is_recurrence_exception'];
+		$row['is_relative'] = (bool) $row['is_relative'];
+		$row['notification_date'] = (int) $row['notification_date'];
+		$row['is_repeat_based'] = (bool) $row['is_repeat_based'];
+
+		return $row;
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/INotificationProvider.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder;
+
+use OCP\IUser;
+use Sabre\VObject\Component\VEvent;
+
+/**
+ * Interface INotificationProvider
+ *
+ * @package OCA\DAV\CalDAV\Reminder
+ */
+interface INotificationProvider {
+
+	/**
+	 * Send notification
+	 *
+	 * @param VEvent $vevent
+	 * @param string|null $calendarDisplayName
+	 * @param string[] $principalEmailAddresses All email addresses associated to the principal owning the calendar object
+	 * @param IUser[] $users
+	 * @return void
+	 */
+	public function send(VEvent $vevent,
+		?string $calendarDisplayName,
+		array  $principalEmailAddresses,
+		array $users = []): void;
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/NotificationProvider/AbstractProvider.php

@@ -0,0 +1,192 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Thomas Citharel
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Joas Schilling <coding@schilljs.com>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder\NotificationProvider;
+
+use OCA\DAV\CalDAV\Reminder\INotificationProvider;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\L10N\IFactory as L10NFactory;
+use Psr\Log\LoggerInterface;
+use Sabre\VObject\Component\VEvent;
+use Sabre\VObject\DateTimeParser;
+use Sabre\VObject\Property;
+
+/**
+ * Class AbstractProvider
+ *
+ * @package OCA\DAV\CalDAV\Reminder\NotificationProvider
+ */
+abstract class AbstractProvider implements INotificationProvider {
+
+	/** @var string */
+	public const NOTIFICATION_TYPE = '';
+
+	protected LoggerInterface $logger;
+
+	/** @var L10NFactory */
+	protected $l10nFactory;
+
+	/** @var IL10N[] */
+	private $l10ns;
+
+	/** @var string */
+	private $fallbackLanguage;
+
+	/** @var IURLGenerator */
+	protected $urlGenerator;
+
+	/** @var IConfig */
+	protected $config;
+
+	public function __construct(LoggerInterface $logger,
+		L10NFactory $l10nFactory,
+		IURLGenerator $urlGenerator,
+		IConfig $config) {
+		$this->logger = $logger;
+		$this->l10nFactory = $l10nFactory;
+		$this->urlGenerator = $urlGenerator;
+		$this->config = $config;
+	}
+
+	/**
+	 * Send notification
+	 *
+	 * @param VEvent $vevent
+	 * @param string|null $calendarDisplayName
+	 * @param string[] $principalEmailAddresses
+	 * @param IUser[] $users
+	 * @return void
+	 */
+	abstract public function send(VEvent $vevent,
+		?string $calendarDisplayName,
+		array $principalEmailAddresses,
+		array $users = []): void;
+
+	/**
+	 * @return string
+	 */
+	protected function getFallbackLanguage():string {
+		if ($this->fallbackLanguage) {
+			return $this->fallbackLanguage;
+		}
+
+		$fallbackLanguage = $this->l10nFactory->findGenericLanguage();
+		$this->fallbackLanguage = $fallbackLanguage;
+
+		return $fallbackLanguage;
+	}
+
+	/**
+	 * @param string $lang
+	 * @return bool
+	 */
+	protected function hasL10NForLang(string $lang):bool {
+		return $this->l10nFactory->languageExists('dav', $lang);
+	}
+
+	/**
+	 * @param string $lang
+	 * @return IL10N
+	 */
+	protected function getL10NForLang(string $lang):IL10N {
+		if (isset($this->l10ns[$lang])) {
+			return $this->l10ns[$lang];
+		}
+
+		$l10n = $this->l10nFactory->get('dav', $lang);
+		$this->l10ns[$lang] = $l10n;
+
+		return $l10n;
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return string
+	 */
+	private function getStatusOfEvent(VEvent $vevent):string {
+		if ($vevent->STATUS) {
+			return (string) $vevent->STATUS;
+		}
+
+		// Doesn't say so in the standard,
+		// but we consider events without a status
+		// to be confirmed
+		return 'CONFIRMED';
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return bool
+	 */
+	protected function isEventTentative(VEvent $vevent):bool {
+		return $this->getStatusOfEvent($vevent) === 'TENTATIVE';
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return Property\ICalendar\DateTime
+	 */
+	protected function getDTEndFromEvent(VEvent $vevent):Property\ICalendar\DateTime {
+		if (isset($vevent->DTEND)) {
+			return $vevent->DTEND;
+		}
+
+		if (isset($vevent->DURATION)) {
+			$isFloating = $vevent->DTSTART->isFloating();
+			/** @var Property\ICalendar\DateTime $end */
+			$end = clone $vevent->DTSTART;
+			$endDateTime = $end->getDateTime();
+			$endDateTime = $endDateTime->add(DateTimeParser::parse($vevent->DURATION->getValue()));
+			$end->setDateTime($endDateTime, $isFloating);
+
+			return $end;
+		}
+
+		if (!$vevent->DTSTART->hasTime()) {
+			$isFloating = $vevent->DTSTART->isFloating();
+			/** @var Property\ICalendar\DateTime $end */
+			$end = clone $vevent->DTSTART;
+			$endDateTime = $end->getDateTime();
+			$endDateTime = $endDateTime->modify('+1 day');
+			$end->setDateTime($endDateTime, $isFloating);
+
+			return $end;
+		}
+
+		return clone $vevent->DTSTART;
+	}
+
+	protected function getCalendarDisplayNameFallback(string $lang): string {
+		return $this->getL10NForLang($lang)->t('Untitled calendar');
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/NotificationProvider/AudioProvider.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder\NotificationProvider;
+
+/**
+ * Class AudioProvider
+ *
+ * This class only extends PushProvider at the moment. It does not provide true
+ * audio-alarms yet, but it's better than no alarm at all right now.
+ *
+ * @package OCA\DAV\CalDAV\Reminder\NotificationProvider
+ */
+class AudioProvider extends PushProvider {
+
+	/** @var string */
+	public const NOTIFICATION_TYPE = 'AUDIO';
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/NotificationProvider/EmailProvider.php

@@ -0,0 +1,465 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Thomas Citharel
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Joas Schilling <coding@schilljs.com>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder\NotificationProvider;
+
+use DateTime;
+use OCP\IConfig;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\L10N\IFactory as L10NFactory;
+use OCP\Mail\Headers\AutoSubmitted;
+use OCP\Mail\IEMailTemplate;
+use OCP\Mail\IMailer;
+use Psr\Log\LoggerInterface;
+use Sabre\VObject;
+use Sabre\VObject\Component\VEvent;
+use Sabre\VObject\Parameter;
+use Sabre\VObject\Property;
+
+/**
+ * Class EmailProvider
+ *
+ * @package OCA\DAV\CalDAV\Reminder\NotificationProvider
+ */
+class EmailProvider extends AbstractProvider {
+	/** @var string */
+	public const NOTIFICATION_TYPE = 'EMAIL';
+
+	private IMailer $mailer;
+
+	public function __construct(IConfig $config,
+		IMailer $mailer,
+		LoggerInterface $logger,
+		L10NFactory $l10nFactory,
+		IURLGenerator $urlGenerator) {
+		parent::__construct($logger, $l10nFactory, $urlGenerator, $config);
+		$this->mailer = $mailer;
+	}
+
+	/**
+	 * Send out notification via email
+	 *
+	 * @param VEvent $vevent
+	 * @param string|null $calendarDisplayName
+	 * @param string[] $principalEmailAddresses
+	 * @param array $users
+	 * @throws \Exception
+	 */
+	public function send(VEvent $vevent,
+		?string $calendarDisplayName,
+		array $principalEmailAddresses,
+		array $users = []):void {
+		$fallbackLanguage = $this->getFallbackLanguage();
+
+		$organizerEmailAddress = null;
+		if (isset($vevent->ORGANIZER)) {
+			$organizerEmailAddress = $this->getEMailAddressOfAttendee($vevent->ORGANIZER);
+		}
+
+		$emailAddressesOfSharees = $this->getEMailAddressesOfAllUsersWithWriteAccessToCalendar($users);
+		$emailAddressesOfAttendees = [];
+		if (count($principalEmailAddresses) === 0
+			|| ($organizerEmailAddress && in_array($organizerEmailAddress, $principalEmailAddresses, true))
+		) {
+			$emailAddressesOfAttendees = $this->getAllEMailAddressesFromEvent($vevent);
+		}
+
+		// Quote from php.net:
+		// If the input arrays have the same string keys, then the later value for that key will overwrite the previous one.
+		// => if there are duplicate email addresses, it will always take the system value
+		$emailAddresses = array_merge(
+			$emailAddressesOfAttendees,
+			$emailAddressesOfSharees
+		);
+
+		$sortedByLanguage = $this->sortEMailAddressesByLanguage($emailAddresses, $fallbackLanguage);
+		$organizer = $this->getOrganizerEMailAndNameFromEvent($vevent);
+
+		foreach ($sortedByLanguage as $lang => $emailAddresses) {
+			if (!$this->hasL10NForLang($lang)) {
+				$lang = $fallbackLanguage;
+			}
+			$l10n = $this->getL10NForLang($lang);
+			$fromEMail = \OCP\Util::getDefaultEmailAddress('reminders-noreply');
+
+			$template = $this->mailer->createEMailTemplate('dav.calendarReminder');
+			$template->addHeader();
+			$this->addSubjectAndHeading($template, $l10n, $vevent);
+			$this->addBulletList($template, $l10n, $calendarDisplayName ?? $this->getCalendarDisplayNameFallback($lang), $vevent);
+			$template->addFooter();
+
+			foreach ($emailAddresses as $emailAddress) {
+				if (!$this->mailer->validateMailAddress($emailAddress)) {
+					$this->logger->error('Email address {address} for reminder notification is incorrect', ['app' => 'dav', 'address' => $emailAddress]);
+					continue;
+				}
+
+				$message = $this->mailer->createMessage();
+				$message->setFrom([$fromEMail]);
+				if ($organizer) {
+					$message->setReplyTo($organizer);
+				}
+				$message->setTo([$emailAddress]);
+				$message->useTemplate($template);
+				$message->setAutoSubmitted(AutoSubmitted::VALUE_AUTO_GENERATED);
+
+				try {
+					$failed = $this->mailer->send($message);
+					if ($failed) {
+						$this->logger->error('Unable to deliver message to {failed}', ['app' => 'dav', 'failed' => implode(', ', $failed)]);
+					}
+				} catch (\Exception $ex) {
+					$this->logger->error($ex->getMessage(), ['app' => 'dav', 'exception' => $ex]);
+				}
+			}
+		}
+	}
+
+	/**
+	 * @param IEMailTemplate $template
+	 * @param IL10N $l10n
+	 * @param VEvent $vevent
+	 */
+	private function addSubjectAndHeading(IEMailTemplate $template, IL10N $l10n, VEvent $vevent):void {
+		$template->setSubject('Notification: ' . $this->getTitleFromVEvent($vevent, $l10n));
+		$template->addHeading($this->getTitleFromVEvent($vevent, $l10n));
+	}
+
+	/**
+	 * @param IEMailTemplate $template
+	 * @param IL10N $l10n
+	 * @param string $calendarDisplayName
+	 * @param array $eventData
+	 */
+	private function addBulletList(IEMailTemplate $template,
+		IL10N $l10n,
+		string $calendarDisplayName,
+		VEvent $vevent):void {
+		$template->addBodyListItem($calendarDisplayName, $l10n->t('Calendar:'),
+			$this->getAbsoluteImagePath('actions/info.png'));
+
+		$template->addBodyListItem($this->generateDateString($l10n, $vevent), $l10n->t('Date:'),
+			$this->getAbsoluteImagePath('places/calendar.png'));
+
+		if (isset($vevent->LOCATION)) {
+			$template->addBodyListItem((string) $vevent->LOCATION, $l10n->t('Where:'),
+				$this->getAbsoluteImagePath('actions/address.png'));
+		}
+		if (isset($vevent->DESCRIPTION)) {
+			$template->addBodyListItem((string) $vevent->DESCRIPTION, $l10n->t('Description:'),
+				$this->getAbsoluteImagePath('actions/more.png'));
+		}
+	}
+
+	private function getAbsoluteImagePath(string $path):string {
+		return $this->urlGenerator->getAbsoluteURL(
+			$this->urlGenerator->imagePath('core', $path)
+		);
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return array|null
+	 */
+	private function getOrganizerEMailAndNameFromEvent(VEvent $vevent):?array {
+		if (!$vevent->ORGANIZER) {
+			return null;
+		}
+
+		$organizer = $vevent->ORGANIZER;
+		if (strcasecmp($organizer->getValue(), 'mailto:') !== 0) {
+			return null;
+		}
+
+		$organizerEMail = substr($organizer->getValue(), 7);
+
+		if (!$this->mailer->validateMailAddress($organizerEMail)) {
+			return null;
+		}
+
+		$name = $organizer->offsetGet('CN');
+		if ($name instanceof Parameter) {
+			return [$organizerEMail => $name];
+		}
+
+		return [$organizerEMail];
+	}
+
+	/**
+	 * @param array<string, array{LANG?: string}> $emails
+	 * @return array<string, string[]>
+	 */
+	private function sortEMailAddressesByLanguage(array $emails,
+		string $defaultLanguage):array {
+		$sortedByLanguage = [];
+
+		foreach ($emails as $emailAddress => $parameters) {
+			if (isset($parameters['LANG'])) {
+				$lang = $parameters['LANG'];
+			} else {
+				$lang = $defaultLanguage;
+			}
+
+			if (!isset($sortedByLanguage[$lang])) {
+				$sortedByLanguage[$lang] = [];
+			}
+
+			$sortedByLanguage[$lang][] = $emailAddress;
+		}
+
+		return $sortedByLanguage;
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return array<string, array{LANG?: string}>
+	 */
+	private function getAllEMailAddressesFromEvent(VEvent $vevent):array {
+		$emailAddresses = [];
+
+		if (isset($vevent->ATTENDEE)) {
+			foreach ($vevent->ATTENDEE as $attendee) {
+				if (!($attendee instanceof VObject\Property)) {
+					continue;
+				}
+
+				$cuType = $this->getCUTypeOfAttendee($attendee);
+				if (\in_array($cuType, ['RESOURCE', 'ROOM', 'UNKNOWN'])) {
+					// Don't send emails to things
+					continue;
+				}
+
+				$partstat = $this->getPartstatOfAttendee($attendee);
+				if ($partstat === 'DECLINED') {
+					// Don't send out emails to people who declined
+					continue;
+				}
+				if ($partstat === 'DELEGATED') {
+					$delegates = $attendee->offsetGet('DELEGATED-TO');
+					if (!($delegates instanceof VObject\Parameter)) {
+						continue;
+					}
+
+					$emailAddressesOfDelegates = $delegates->getParts();
+					foreach ($emailAddressesOfDelegates as $addressesOfDelegate) {
+						if (strcasecmp($addressesOfDelegate, 'mailto:') === 0) {
+							$delegateEmail = substr($addressesOfDelegate, 7);
+							if ($this->mailer->validateMailAddress($delegateEmail)) {
+								$emailAddresses[$delegateEmail] = [];
+							}
+						}
+					}
+
+					continue;
+				}
+
+				$emailAddressOfAttendee = $this->getEMailAddressOfAttendee($attendee);
+				if ($emailAddressOfAttendee !== null) {
+					$properties = [];
+
+					$langProp = $attendee->offsetGet('LANG');
+					if ($langProp instanceof VObject\Parameter && $langProp->getValue() !== null) {
+						$properties['LANG'] = $langProp->getValue();
+					}
+
+					$emailAddresses[$emailAddressOfAttendee] = $properties;
+				}
+			}
+		}
+
+		if (isset($vevent->ORGANIZER) && $this->hasAttendeeMailURI($vevent->ORGANIZER)) {
+			$organizerEmailAddress = $this->getEMailAddressOfAttendee($vevent->ORGANIZER);
+			if ($organizerEmailAddress !== null) {
+				$emailAddresses[$organizerEmailAddress] = [];
+			}
+		}
+
+		return $emailAddresses;
+	}
+
+	private function getCUTypeOfAttendee(VObject\Property $attendee):string {
+		$cuType = $attendee->offsetGet('CUTYPE');
+		if ($cuType instanceof VObject\Parameter) {
+			return strtoupper($cuType->getValue());
+		}
+
+		return 'INDIVIDUAL';
+	}
+
+	private function getPartstatOfAttendee(VObject\Property $attendee):string {
+		$partstat = $attendee->offsetGet('PARTSTAT');
+		if ($partstat instanceof VObject\Parameter) {
+			return strtoupper($partstat->getValue());
+		}
+
+		return 'NEEDS-ACTION';
+	}
+
+	private function hasAttendeeMailURI(VObject\Property $attendee): bool {
+		return stripos($attendee->getValue(), 'mailto:') === 0;
+	}
+
+	private function getEMailAddressOfAttendee(VObject\Property $attendee): ?string {
+		if (!$this->hasAttendeeMailURI($attendee)) {
+			return null;
+		}
+		$attendeeEMail = substr($attendee->getValue(), 7);
+		if (!$this->mailer->validateMailAddress($attendeeEMail)) {
+			return null;
+		}
+
+		return $attendeeEMail;
+	}
+
+	/**
+	 * @param IUser[] $users
+	 * @return array<string, array{LANG?: string}>
+	 */
+	private function getEMailAddressesOfAllUsersWithWriteAccessToCalendar(array $users):array {
+		$emailAddresses = [];
+
+		foreach ($users as $user) {
+			$emailAddress = $user->getEMailAddress();
+			if ($emailAddress) {
+				$lang = $this->l10nFactory->getUserLanguage($user);
+				if ($lang) {
+					$emailAddresses[$emailAddress] = [
+						'LANG' => $lang,
+					];
+				} else {
+					$emailAddresses[$emailAddress] = [];
+				}
+			}
+		}
+
+		return $emailAddresses;
+	}
+
+	/**
+	 * @throws \Exception
+	 */
+	private function generateDateString(IL10N $l10n, VEvent $vevent): string {
+		$isAllDay = $vevent->DTSTART instanceof Property\ICalendar\Date;
+
+		/** @var Property\ICalendar\Date | Property\ICalendar\DateTime $dtstart */
+		/** @var Property\ICalendar\Date | Property\ICalendar\DateTime $dtend */
+		/** @var \DateTimeImmutable $dtstartDt */
+		$dtstartDt = $vevent->DTSTART->getDateTime();
+		/** @var \DateTimeImmutable $dtendDt */
+		$dtendDt = $this->getDTEndFromEvent($vevent)->getDateTime();
+
+		$diff = $dtstartDt->diff($dtendDt);
+
+		$dtstartDt = new \DateTime($dtstartDt->format(\DateTimeInterface::ATOM));
+		$dtendDt = new \DateTime($dtendDt->format(\DateTimeInterface::ATOM));
+
+		if ($isAllDay) {
+			// One day event
+			if ($diff->days === 1) {
+				return $this->getDateString($l10n, $dtstartDt);
+			}
+
+			return implode(' - ', [
+				$this->getDateString($l10n, $dtstartDt),
+				$this->getDateString($l10n, $dtendDt),
+			]);
+		}
+
+		$startTimezone = $endTimezone = null;
+		if (!$vevent->DTSTART->isFloating()) {
+			$startTimezone = $vevent->DTSTART->getDateTime()->getTimezone()->getName();
+			$endTimezone = $this->getDTEndFromEvent($vevent)->getDateTime()->getTimezone()->getName();
+		}
+
+		$localeStart = implode(', ', [
+			$this->getWeekDayName($l10n, $dtstartDt),
+			$this->getDateTimeString($l10n, $dtstartDt)
+		]);
+
+		// always show full date with timezone if timezones are different
+		if ($startTimezone !== $endTimezone) {
+			$localeEnd = implode(', ', [
+				$this->getWeekDayName($l10n, $dtendDt),
+				$this->getDateTimeString($l10n, $dtendDt)
+			]);
+
+			return $localeStart
+				. ' (' . $startTimezone . ') '
+				. ' - '
+				. $localeEnd
+				. ' (' . $endTimezone . ')';
+		}
+
+		// Show only the time if the day is the same
+		$localeEnd = $this->isDayEqual($dtstartDt, $dtendDt)
+			? $this->getTimeString($l10n, $dtendDt)
+			: implode(', ', [
+				$this->getWeekDayName($l10n, $dtendDt),
+				$this->getDateTimeString($l10n, $dtendDt)
+			]);
+
+		return $localeStart
+			. ' - '
+			. $localeEnd
+			. ' (' . $startTimezone . ')';
+	}
+
+	private function isDayEqual(DateTime $dtStart,
+		DateTime $dtEnd):bool {
+		return $dtStart->format('Y-m-d') === $dtEnd->format('Y-m-d');
+	}
+
+	private function getWeekDayName(IL10N $l10n, DateTime $dt):string {
+		return (string)$l10n->l('weekdayName', $dt, ['width' => 'abbreviated']);
+	}
+
+	private function getDateString(IL10N $l10n, DateTime $dt):string {
+		return (string)$l10n->l('date', $dt, ['width' => 'medium']);
+	}
+
+	private function getDateTimeString(IL10N $l10n, DateTime $dt):string {
+		return (string)$l10n->l('datetime', $dt, ['width' => 'medium|short']);
+	}
+
+	private function getTimeString(IL10N $l10n, DateTime $dt):string {
+		return (string)$l10n->l('time', $dt, ['width' => 'short']);
+	}
+
+	private function getTitleFromVEvent(VEvent $vevent, IL10N $l10n):string {
+		if (isset($vevent->SUMMARY)) {
+			return (string)$vevent->SUMMARY;
+		}
+
+		return $l10n->t('Untitled event');
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/NotificationProvider/ProviderNotAvailableException.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2018 Thomas Citharel <tcit@tcit.fr>
+ *
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder\NotificationProvider;
+
+class ProviderNotAvailableException extends \Exception {
+
+	/**
+	 * ProviderNotAvailableException constructor.
+	 *
+	 * @since 16.0.0
+	 *
+	 * @param string $type ReminderType
+	 */
+	public function __construct(string $type) {
+		parent::__construct("No notification provider for type $type available");
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/NotificationProvider/PushProvider.php

@@ -0,0 +1,142 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Thomas Citharel
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder\NotificationProvider;
+
+use OCA\DAV\AppInfo\Application;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IConfig;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\L10N\IFactory as L10NFactory;
+use OCP\Notification\IManager;
+use OCP\Notification\INotification;
+use Psr\Log\LoggerInterface;
+use Sabre\VObject\Component\VEvent;
+use Sabre\VObject\Property;
+
+/**
+ * Class PushProvider
+ *
+ * @package OCA\DAV\CalDAV\Reminder\NotificationProvider
+ */
+class PushProvider extends AbstractProvider {
+
+	/** @var string */
+	public const NOTIFICATION_TYPE = 'DISPLAY';
+
+	/** @var IManager */
+	private $manager;
+
+	/** @var ITimeFactory */
+	private $timeFactory;
+
+	public function __construct(IConfig $config,
+		IManager $manager,
+		LoggerInterface $logger,
+		L10NFactory $l10nFactory,
+		IURLGenerator $urlGenerator,
+		ITimeFactory $timeFactory) {
+		parent::__construct($logger, $l10nFactory, $urlGenerator, $config);
+		$this->manager = $manager;
+		$this->timeFactory = $timeFactory;
+	}
+
+	/**
+	 * Send push notification to all users.
+	 *
+	 * @param VEvent $vevent
+	 * @param string|null $calendarDisplayName
+	 * @param string[] $principalEmailAddresses
+	 * @param IUser[] $users
+	 * @throws \Exception
+	 */
+	public function send(VEvent $vevent,
+		?string $calendarDisplayName,
+		array $principalEmailAddresses,
+		array $users = []):void {
+		if ($this->config->getAppValue('dav', 'sendEventRemindersPush', 'yes') !== 'yes') {
+			return;
+		}
+
+		$eventDetails = $this->extractEventDetails($vevent);
+		$eventUUID = (string) $vevent->UID;
+		if (!$eventUUID) {
+			return;
+		};
+		$eventUUIDHash = hash('sha256', $eventUUID, false);
+
+		foreach ($users as $user) {
+			$eventDetails['calendar_displayname'] = $calendarDisplayName ?? $this->getCalendarDisplayNameFallback($this->l10nFactory->getUserLanguage($user));
+
+			/** @var INotification $notification */
+			$notification = $this->manager->createNotification();
+			$notification->setApp(Application::APP_ID)
+				->setUser($user->getUID())
+				->setDateTime($this->timeFactory->getDateTime())
+				->setObject(Application::APP_ID, $eventUUIDHash)
+				->setSubject('calendar_reminder', [
+					'title' => $eventDetails['title'],
+					'start_atom' => $eventDetails['start_atom']
+				])
+				->setMessage('calendar_reminder', $eventDetails);
+
+			$this->manager->notify($notification);
+		}
+	}
+
+	/**
+	 * @throws \Exception
+	 */
+	protected function extractEventDetails(VEvent $vevent):array {
+		/** @var Property\ICalendar\DateTime $start */
+		$start = $vevent->DTSTART;
+		$end = $this->getDTEndFromEvent($vevent);
+
+		return [
+			'title' => isset($vevent->SUMMARY)
+				? ((string) $vevent->SUMMARY)
+				: null,
+			'description' => isset($vevent->DESCRIPTION)
+				? ((string) $vevent->DESCRIPTION)
+				: null,
+			'location' => isset($vevent->LOCATION)
+				? ((string) $vevent->LOCATION)
+				: null,
+			'all_day' => $start instanceof Property\ICalendar\Date,
+			'start_atom' => $start->getDateTime()->format(\DateTimeInterface::ATOM),
+			'start_is_floating' => $start->isFloating(),
+			'start_timezone' => $start->getDateTime()->getTimezone()->getName(),
+			'end_atom' => $end->getDateTime()->format(\DateTimeInterface::ATOM),
+			'end_is_floating' => $end->isFloating(),
+			'end_timezone' => $end->getDateTime()->getTimezone()->getName(),
+		];
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/NotificationProviderManager.php

@@ -0,0 +1,84 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Thomas Citharel
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder;
+
+/**
+ * Class NotificationProviderManager
+ *
+ * @package OCA\DAV\CalDAV\Reminder
+ */
+class NotificationProviderManager {
+
+	/** @var INotificationProvider[] */
+	private $providers = [];
+
+	/**
+	 * Checks whether a provider for a given ACTION exists
+	 *
+	 * @param string $type
+	 * @return bool
+	 */
+	public function hasProvider(string $type):bool {
+		return (\in_array($type, ReminderService::REMINDER_TYPES, true)
+			&& isset($this->providers[$type]));
+	}
+
+	/**
+	 * Get provider for a given ACTION
+	 *
+	 * @param string $type
+	 * @return INotificationProvider
+	 * @throws NotificationProvider\ProviderNotAvailableException
+	 * @throws NotificationTypeDoesNotExistException
+	 */
+	public function getProvider(string $type):INotificationProvider {
+		if (in_array($type, ReminderService::REMINDER_TYPES, true)) {
+			if (isset($this->providers[$type])) {
+				return $this->providers[$type];
+			}
+			throw new NotificationProvider\ProviderNotAvailableException($type);
+		}
+		throw new NotificationTypeDoesNotExistException($type);
+	}
+
+	/**
+	 * Registers a new provider
+	 *
+	 * @param string $providerClassName
+	 * @throws \OCP\AppFramework\QueryException
+	 */
+	public function registerProvider(string $providerClassName):void {
+		$provider = \OC::$server->query($providerClassName);
+
+		if (!$provider instanceof INotificationProvider) {
+			throw new \InvalidArgumentException('Invalid notification provider registered');
+		}
+
+		$this->providers[$provider::NOTIFICATION_TYPE] = $provider;
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/NotificationTypeDoesNotExistException.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Thomas Citharel
+ *
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder;
+
+class NotificationTypeDoesNotExistException extends \Exception {
+
+	/**
+	 * NotificationTypeDoesNotExistException constructor.
+	 *
+	 * @since 16.0.0
+	 *
+	 * @param string $type ReminderType
+	 */
+	public function __construct(string $type) {
+		parent::__construct("Type $type is not an accepted type of notification");
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/Notifier.php

@@ -0,0 +1,341 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Thomas Citharel
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder;
+
+use DateTime;
+use OCA\DAV\AppInfo\Application;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\L10N\IFactory;
+use OCP\Notification\AlreadyProcessedException;
+use OCP\Notification\INotification;
+use OCP\Notification\INotifier;
+
+/**
+ * Class Notifier
+ *
+ * @package OCA\DAV\CalDAV\Reminder
+ */
+class Notifier implements INotifier {
+
+	/** @var IFactory */
+	private $l10nFactory;
+
+	/** @var IURLGenerator */
+	private $urlGenerator;
+
+	/** @var IL10N */
+	private $l10n;
+
+	/** @var ITimeFactory */
+	private $timeFactory;
+
+	/**
+	 * Notifier constructor.
+	 *
+	 * @param IFactory $factory
+	 * @param IURLGenerator $urlGenerator
+	 * @param ITimeFactory $timeFactory
+	 */
+	public function __construct(IFactory $factory,
+		IURLGenerator $urlGenerator,
+		ITimeFactory $timeFactory) {
+		$this->l10nFactory = $factory;
+		$this->urlGenerator = $urlGenerator;
+		$this->timeFactory = $timeFactory;
+	}
+
+	/**
+	 * Identifier of the notifier, only use [a-z0-9_]
+	 *
+	 * @return string
+	 * @since 17.0.0
+	 */
+	public function getID():string {
+		return Application::APP_ID;
+	}
+
+	/**
+	 * Human readable name describing the notifier
+	 *
+	 * @return string
+	 * @since 17.0.0
+	 */
+	public function getName():string {
+		return $this->l10nFactory->get('dav')->t('Calendar');
+	}
+
+	/**
+	 * Prepare sending the notification
+	 *
+	 * @param INotification $notification
+	 * @param string $languageCode The code of the language that should be used to prepare the notification
+	 * @return INotification
+	 * @throws \Exception
+	 */
+	public function prepare(INotification $notification,
+		string $languageCode):INotification {
+		if ($notification->getApp() !== Application::APP_ID) {
+			throw new \InvalidArgumentException('Notification not from this app');
+		}
+
+		// Read the language from the notification
+		$this->l10n = $this->l10nFactory->get('dav', $languageCode);
+
+		// Handle notifier subjects
+		switch ($notification->getSubject()) {
+			case 'calendar_reminder':
+				return $this->prepareReminderNotification($notification);
+
+			default:
+				throw new \InvalidArgumentException('Unknown subject');
+
+		}
+	}
+
+	/**
+	 * @param INotification $notification
+	 * @return INotification
+	 */
+	private function prepareReminderNotification(INotification $notification):INotification {
+		$imagePath = $this->urlGenerator->imagePath('core', 'places/calendar.svg');
+		$iconUrl = $this->urlGenerator->getAbsoluteURL($imagePath);
+		$notification->setIcon($iconUrl);
+
+		$this->prepareNotificationSubject($notification);
+		$this->prepareNotificationMessage($notification);
+
+		return $notification;
+	}
+
+	/**
+	 * Sets the notification subject based on the parameters set in PushProvider
+	 *
+	 * @param INotification $notification
+	 */
+	private function prepareNotificationSubject(INotification $notification): void {
+		$parameters = $notification->getSubjectParameters();
+
+		$startTime = \DateTime::createFromFormat(\DateTimeInterface::ATOM, $parameters['start_atom']);
+		$now = $this->timeFactory->getDateTime();
+		$title = $this->getTitleFromParameters($parameters);
+
+		$diff = $startTime->diff($now);
+		if ($diff === false) {
+			return;
+		}
+
+		$components = [];
+		if ($diff->y) {
+			$components[] = $this->l10n->n('%n year', '%n years', $diff->y);
+		}
+		if ($diff->m) {
+			$components[] = $this->l10n->n('%n month', '%n months', $diff->m);
+		}
+		if ($diff->d) {
+			$components[] = $this->l10n->n('%n day', '%n days', $diff->d);
+		}
+		if ($diff->h) {
+			$components[] = $this->l10n->n('%n hour', '%n hours', $diff->h);
+		}
+		if ($diff->i) {
+			$components[] = $this->l10n->n('%n minute', '%n minutes', $diff->i);
+		}
+
+		if (count($components) > 0 && !$this->hasPhpDatetimeDiffBug()) {
+			// Limiting to the first three components to prevent
+			// the string from getting too long
+			$firstThreeComponents = array_slice($components, 0, 2);
+			$diffLabel = implode(', ', $firstThreeComponents);
+
+			if ($diff->invert) {
+				$title = $this->l10n->t('%s (in %s)', [$title, $diffLabel]);
+			} else {
+				$title = $this->l10n->t('%s (%s ago)', [$title, $diffLabel]);
+			}
+		}
+
+		$notification->setParsedSubject($title);
+	}
+
+	/**
+	 * @see https://github.com/nextcloud/server/issues/41615
+	 * @see https://github.com/php/php-src/issues/9699
+	 */
+	private function hasPhpDatetimeDiffBug(): bool {
+		$d1 = DateTime::createFromFormat(\DateTimeInterface::ATOM, '2023-11-22T11:52:00+01:00');
+		$d2 = new DateTime('2023-11-22T10:52:03', new \DateTimeZone('UTC'));
+
+		// The difference is 3 seconds, not -1year+11months+…
+		return $d1->diff($d2)->y < 0;
+	}
+
+	/**
+	 * Sets the notification message based on the parameters set in PushProvider
+	 *
+	 * @param INotification $notification
+	 */
+	private function prepareNotificationMessage(INotification $notification): void {
+		$parameters = $notification->getMessageParameters();
+
+		$description = [
+			$this->l10n->t('Calendar: %s', $parameters['calendar_displayname']),
+			$this->l10n->t('Date: %s', $this->generateDateString($parameters)),
+		];
+		if ($parameters['description']) {
+			$description[] = $this->l10n->t('Description: %s', $parameters['description']);
+		}
+		if ($parameters['location']) {
+			$description[] = $this->l10n->t('Where: %s', $parameters['location']);
+		}
+
+		$message = implode("\r\n", $description);
+		$notification->setParsedMessage($message);
+	}
+
+	/**
+	 * @param array $parameters
+	 * @return string
+	 */
+	private function getTitleFromParameters(array $parameters):string {
+		return $parameters['title'] ?? $this->l10n->t('Untitled event');
+	}
+
+	/**
+	 * @param array $parameters
+	 * @return string
+	 * @throws \Exception
+	 */
+	private function generateDateString(array $parameters):string {
+		$startDateTime = DateTime::createFromFormat(\DateTimeInterface::ATOM, $parameters['start_atom']);
+		$endDateTime = DateTime::createFromFormat(\DateTimeInterface::ATOM, $parameters['end_atom']);
+
+		// If the event has already ended, dismiss the notification
+		if ($endDateTime < $this->timeFactory->getDateTime()) {
+			throw new AlreadyProcessedException();
+		}
+
+		$isAllDay = $parameters['all_day'];
+		$diff = $startDateTime->diff($endDateTime);
+
+		if ($isAllDay) {
+			// One day event
+			if ($diff->days === 1) {
+				return $this->getDateString($startDateTime);
+			}
+
+			return implode(' - ', [
+				$this->getDateString($startDateTime),
+				$this->getDateString($endDateTime),
+			]);
+		}
+
+		$startTimezone = $endTimezone = null;
+		if (!$parameters['start_is_floating']) {
+			$startTimezone = $parameters['start_timezone'];
+			$endTimezone = $parameters['end_timezone'];
+		}
+
+		$localeStart = implode(', ', [
+			$this->getWeekDayName($startDateTime),
+			$this->getDateTimeString($startDateTime)
+		]);
+
+		// always show full date with timezone if timezones are different
+		if ($startTimezone !== $endTimezone) {
+			$localeEnd = implode(', ', [
+				$this->getWeekDayName($endDateTime),
+				$this->getDateTimeString($endDateTime)
+			]);
+
+			return $localeStart
+				. ' (' . $startTimezone . ') '
+				. ' - '
+				. $localeEnd
+				. ' (' . $endTimezone . ')';
+		}
+
+		// Show only the time if the day is the same
+		$localeEnd = $this->isDayEqual($startDateTime, $endDateTime)
+			? $this->getTimeString($endDateTime)
+			: implode(', ', [
+				$this->getWeekDayName($endDateTime),
+				$this->getDateTimeString($endDateTime)
+			]);
+
+		return $localeStart
+			. ' - '
+			. $localeEnd
+			. ' (' . $startTimezone . ')';
+	}
+
+	/**
+	 * @param DateTime $dtStart
+	 * @param DateTime $dtEnd
+	 * @return bool
+	 */
+	private function isDayEqual(DateTime $dtStart,
+		DateTime $dtEnd):bool {
+		return $dtStart->format('Y-m-d') === $dtEnd->format('Y-m-d');
+	}
+
+	/**
+	 * @param DateTime $dt
+	 * @return string
+	 */
+	private function getWeekDayName(DateTime $dt):string {
+		return (string)$this->l10n->l('weekdayName', $dt, ['width' => 'abbreviated']);
+	}
+
+	/**
+	 * @param DateTime $dt
+	 * @return string
+	 */
+	private function getDateString(DateTime $dt):string {
+		return (string)$this->l10n->l('date', $dt, ['width' => 'medium']);
+	}
+
+	/**
+	 * @param DateTime $dt
+	 * @return string
+	 */
+	private function getDateTimeString(DateTime $dt):string {
+		return (string)$this->l10n->l('datetime', $dt, ['width' => 'medium|short']);
+	}
+
+	/**
+	 * @param DateTime $dt
+	 * @return string
+	 */
+	private function getTimeString(DateTime $dt):string {
+		return (string)$this->l10n->l('time', $dt, ['width' => 'short']);
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Reminder/ReminderService.php

@@ -0,0 +1,886 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2019, Thomas Citharel
+ * @copyright Copyright (c) 2019, Georg Ehrke
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Joas Schilling <coding@schilljs.com>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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/>.
+ *
+ */
+namespace OCA\DAV\CalDAV\Reminder;
+
+use DateTimeImmutable;
+use DateTimeZone;
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCA\DAV\Connector\Sabre\Principal;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IConfig;
+use OCP\IGroup;
+use OCP\IGroupManager;
+use OCP\IUser;
+use OCP\IUserManager;
+use Psr\Log\LoggerInterface;
+use Sabre\VObject;
+use Sabre\VObject\Component\VAlarm;
+use Sabre\VObject\Component\VEvent;
+use Sabre\VObject\InvalidDataException;
+use Sabre\VObject\ParseException;
+use Sabre\VObject\Recur\EventIterator;
+use Sabre\VObject\Recur\MaxInstancesExceededException;
+use Sabre\VObject\Recur\NoInstancesException;
+use function count;
+use function strcasecmp;
+
+class ReminderService {
+
+	/** @var Backend */
+	private $backend;
+
+	/** @var NotificationProviderManager */
+	private $notificationProviderManager;
+
+	/** @var IUserManager */
+	private $userManager;
+
+	/** @var IGroupManager */
+	private $groupManager;
+
+	/** @var CalDavBackend */
+	private $caldavBackend;
+
+	/** @var ITimeFactory */
+	private $timeFactory;
+
+	/** @var IConfig */
+	private $config;
+
+	/** @var LoggerInterface */
+	private $logger;
+
+	/** @var Principal */
+	private $principalConnector;
+
+	public const REMINDER_TYPE_EMAIL = 'EMAIL';
+	public const REMINDER_TYPE_DISPLAY = 'DISPLAY';
+	public const REMINDER_TYPE_AUDIO = 'AUDIO';
+
+	/**
+	 * @var String[]
+	 *
+	 * Official RFC5545 reminder types
+	 */
+	public const REMINDER_TYPES = [
+		self::REMINDER_TYPE_EMAIL,
+		self::REMINDER_TYPE_DISPLAY,
+		self::REMINDER_TYPE_AUDIO
+	];
+
+	public function __construct(Backend $backend,
+		NotificationProviderManager $notificationProviderManager,
+		IUserManager $userManager,
+		IGroupManager $groupManager,
+		CalDavBackend $caldavBackend,
+		ITimeFactory $timeFactory,
+		IConfig $config,
+		LoggerInterface $logger,
+		Principal $principalConnector) {
+		$this->backend = $backend;
+		$this->notificationProviderManager = $notificationProviderManager;
+		$this->userManager = $userManager;
+		$this->groupManager = $groupManager;
+		$this->caldavBackend = $caldavBackend;
+		$this->timeFactory = $timeFactory;
+		$this->config = $config;
+		$this->logger = $logger;
+		$this->principalConnector = $principalConnector;
+	}
+
+	/**
+	 * Process reminders to activate
+	 *
+	 * @throws NotificationProvider\ProviderNotAvailableException
+	 * @throws NotificationTypeDoesNotExistException
+	 */
+	public function processReminders() :void {
+		$reminders = $this->backend->getRemindersToProcess();
+		$this->logger->debug('{numReminders} reminders to process', [
+			'numReminders' => count($reminders),
+		]);
+
+		foreach ($reminders as $reminder) {
+			$calendarData = is_resource($reminder['calendardata'])
+				? stream_get_contents($reminder['calendardata'])
+				: $reminder['calendardata'];
+
+			if (!$calendarData) {
+				continue;
+			}
+
+			$vcalendar = $this->parseCalendarData($calendarData);
+			if (!$vcalendar) {
+				$this->logger->debug('Reminder {id} does not belong to a valid calendar', [
+					'id' => $reminder['id'],
+				]);
+				$this->backend->removeReminder($reminder['id']);
+				continue;
+			}
+
+			try {
+				$vevent = $this->getVEventByRecurrenceId($vcalendar, $reminder['recurrence_id'], $reminder['is_recurrence_exception']);
+			} catch (MaxInstancesExceededException $e) {
+				$this->logger->debug('Recurrence with too many instances detected, skipping VEVENT', ['exception' => $e]);
+				$this->backend->removeReminder($reminder['id']);
+				continue;
+			}
+
+			if (!$vevent) {
+				$this->logger->debug('Reminder {id} does not belong to a valid event', [
+					'id' => $reminder['id'],
+				]);
+				$this->backend->removeReminder($reminder['id']);
+				continue;
+			}
+
+			if ($this->wasEventCancelled($vevent)) {
+				$this->logger->debug('Reminder {id} belongs to a cancelled event', [
+					'id' => $reminder['id'],
+				]);
+				$this->deleteOrProcessNext($reminder, $vevent);
+				continue;
+			}
+
+			if (!$this->notificationProviderManager->hasProvider($reminder['type'])) {
+				$this->logger->debug('Reminder {id} does not belong to a valid notification provider', [
+					'id' => $reminder['id'],
+				]);
+				$this->deleteOrProcessNext($reminder, $vevent);
+				continue;
+			}
+
+			if ($this->config->getAppValue('dav', 'sendEventRemindersToSharedUsers', 'yes') === 'no') {
+				$users = $this->getAllUsersWithWriteAccessToCalendar($reminder['calendar_id']);
+			} else {
+				$users = [];
+			}
+
+			$user = $this->getUserFromPrincipalURI($reminder['principaluri']);
+			if ($user) {
+				$users[] = $user;
+			}
+
+			$userPrincipalEmailAddresses = [];
+			$userPrincipal = $this->principalConnector->getPrincipalByPath($reminder['principaluri']);
+			if ($userPrincipal) {
+				$userPrincipalEmailAddresses = $this->principalConnector->getEmailAddressesOfPrincipal($userPrincipal);
+			}
+
+			$this->logger->debug('Reminder {id} will be sent to {numUsers} users', [
+				'id' => $reminder['id'],
+				'numUsers' => count($users),
+			]);
+			$notificationProvider = $this->notificationProviderManager->getProvider($reminder['type']);
+			$notificationProvider->send($vevent, $reminder['displayname'], $userPrincipalEmailAddresses, $users);
+
+			$this->deleteOrProcessNext($reminder, $vevent);
+		}
+	}
+
+	/**
+	 * @param array $objectData
+	 * @throws VObject\InvalidDataException
+	 */
+	public function onCalendarObjectCreate(array $objectData):void {
+		// We only support VEvents for now
+		if (strcasecmp($objectData['component'], 'vevent') !== 0) {
+			return;
+		}
+
+		$calendarData = is_resource($objectData['calendardata'])
+			? stream_get_contents($objectData['calendardata'])
+			: $objectData['calendardata'];
+
+		if (!$calendarData) {
+			return;
+		}
+
+		$vcalendar = $this->parseCalendarData($calendarData);
+		if (!$vcalendar) {
+			return;
+		}
+		$calendarTimeZone = $this->getCalendarTimeZone((int) $objectData['calendarid']);
+
+		$vevents = $this->getAllVEventsFromVCalendar($vcalendar);
+		if (count($vevents) === 0) {
+			return;
+		}
+
+		$uid = (string) $vevents[0]->UID;
+		$recurrenceExceptions = $this->getRecurrenceExceptionFromListOfVEvents($vevents);
+		$masterItem = $this->getMasterItemFromListOfVEvents($vevents);
+		$now = $this->timeFactory->getDateTime();
+		$isRecurring = $masterItem ? $this->isRecurring($masterItem) : false;
+
+		foreach ($recurrenceExceptions as $recurrenceException) {
+			$eventHash = $this->getEventHash($recurrenceException);
+
+			if (!isset($recurrenceException->VALARM)) {
+				continue;
+			}
+
+			foreach ($recurrenceException->VALARM as $valarm) {
+				/** @var VAlarm $valarm */
+				$alarmHash = $this->getAlarmHash($valarm);
+				$triggerTime = $valarm->getEffectiveTriggerTime();
+				$diff = $now->diff($triggerTime);
+				if ($diff->invert === 1) {
+					continue;
+				}
+
+				$alarms = $this->getRemindersForVAlarm($valarm, $objectData, $calendarTimeZone,
+					$eventHash, $alarmHash, true, true);
+				$this->writeRemindersToDatabase($alarms);
+			}
+		}
+
+		if ($masterItem) {
+			$processedAlarms = [];
+			$masterAlarms = [];
+			$masterHash = $this->getEventHash($masterItem);
+
+			if (!isset($masterItem->VALARM)) {
+				return;
+			}
+
+			foreach ($masterItem->VALARM as $valarm) {
+				$masterAlarms[] = $this->getAlarmHash($valarm);
+			}
+
+			try {
+				$iterator = new EventIterator($vevents, $uid);
+			} catch (NoInstancesException $e) {
+				// This event is recurring, but it doesn't have a single
+				// instance. We are skipping this event from the output
+				// entirely.
+				return;
+			} catch (MaxInstancesExceededException $e) {
+				// The event has more than 3500 recurring-instances
+				// so we can ignore it
+				return;
+			}
+
+			while ($iterator->valid() && count($processedAlarms) < count($masterAlarms)) {
+				$event = $iterator->getEventObject();
+
+				// Recurrence-exceptions are handled separately, so just ignore them here
+				if (\in_array($event, $recurrenceExceptions, true)) {
+					$iterator->next();
+					continue;
+				}
+
+				foreach ($event->VALARM as $valarm) {
+					/** @var VAlarm $valarm */
+					$alarmHash = $this->getAlarmHash($valarm);
+					if (\in_array($alarmHash, $processedAlarms, true)) {
+						continue;
+					}
+
+					if (!\in_array((string) $valarm->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;
+					}
+
+					try {
+						$triggerTime = $valarm->getEffectiveTriggerTime();
+						/**
+						 * @psalm-suppress DocblockTypeContradiction
+						 *   https://github.com/vimeo/psalm/issues/9244
+						 */
+						if ($triggerTime->getTimezone() === false || $triggerTime->getTimezone()->getName() === 'UTC') {
+							$triggerTime = new DateTimeImmutable(
+								$triggerTime->format('Y-m-d H:i:s'),
+								$calendarTimeZone
+							);
+						}
+					} catch (InvalidDataException $e) {
+						continue;
+					}
+
+					// If effective trigger time is in the past
+					// just skip and generate for next event
+					$diff = $now->diff($triggerTime);
+					if ($diff->invert === 1) {
+						// If an absolute alarm is in the past,
+						// just add it to processedAlarms, so
+						// we don't extend till eternity
+						if (!$this->isAlarmRelative($valarm)) {
+							$processedAlarms[] = $alarmHash;
+						}
+
+						continue;
+					}
+
+					$alarms = $this->getRemindersForVAlarm($valarm, $objectData, $calendarTimeZone, $masterHash, $alarmHash, $isRecurring, false);
+					$this->writeRemindersToDatabase($alarms);
+					$processedAlarms[] = $alarmHash;
+				}
+
+				$iterator->next();
+			}
+		}
+	}
+
+	/**
+	 * @param array $objectData
+	 * @throws VObject\InvalidDataException
+	 */
+	public function onCalendarObjectEdit(array $objectData):void {
+		// TODO - this can be vastly improved
+		//  - get cached reminders
+		//  - ...
+
+		$this->onCalendarObjectDelete($objectData);
+		$this->onCalendarObjectCreate($objectData);
+	}
+
+	/**
+	 * @param array $objectData
+	 * @throws VObject\InvalidDataException
+	 */
+	public function onCalendarObjectDelete(array $objectData):void {
+		// We only support VEvents for now
+		if (strcasecmp($objectData['component'], 'vevent') !== 0) {
+			return;
+		}
+
+		$this->backend->cleanRemindersForEvent((int) $objectData['id']);
+	}
+
+	/**
+	 * @param VAlarm $valarm
+	 * @param array $objectData
+	 * @param DateTimeZone $calendarTimeZone
+	 * @param string|null $eventHash
+	 * @param string|null $alarmHash
+	 * @param bool $isRecurring
+	 * @param bool $isRecurrenceException
+	 * @return array
+	 */
+	private function getRemindersForVAlarm(VAlarm $valarm,
+		array $objectData,
+		DateTimeZone $calendarTimeZone,
+		string $eventHash = null,
+		string $alarmHash = null,
+		bool $isRecurring = false,
+		bool $isRecurrenceException = false):array {
+		if ($eventHash === null) {
+			$eventHash = $this->getEventHash($valarm->parent);
+		}
+		if ($alarmHash === null) {
+			$alarmHash = $this->getAlarmHash($valarm);
+		}
+
+		$recurrenceId = $this->getEffectiveRecurrenceIdOfVEvent($valarm->parent);
+		$isRelative = $this->isAlarmRelative($valarm);
+		/** @var DateTimeImmutable $notificationDate */
+		$notificationDate = $valarm->getEffectiveTriggerTime();
+		/**
+		 * @psalm-suppress DocblockTypeContradiction
+		 *   https://github.com/vimeo/psalm/issues/9244
+		 */
+		if ($notificationDate->getTimezone() === false || $notificationDate->getTimezone()->getName() === 'UTC') {
+			$notificationDate = new DateTimeImmutable(
+				$notificationDate->format('Y-m-d H:i:s'),
+				$calendarTimeZone
+			);
+		}
+		$clonedNotificationDate = new \DateTime('now', $notificationDate->getTimezone());
+		$clonedNotificationDate->setTimestamp($notificationDate->getTimestamp());
+
+		$alarms = [];
+
+		$alarms[] = [
+			'calendar_id' => $objectData['calendarid'],
+			'object_id' => $objectData['id'],
+			'uid' => (string) $valarm->parent->UID,
+			'is_recurring' => $isRecurring,
+			'recurrence_id' => $recurrenceId,
+			'is_recurrence_exception' => $isRecurrenceException,
+			'event_hash' => $eventHash,
+			'alarm_hash' => $alarmHash,
+			'type' => (string) $valarm->ACTION,
+			'is_relative' => $isRelative,
+			'notification_date' => $notificationDate->getTimestamp(),
+			'is_repeat_based' => false,
+		];
+
+		$repeat = isset($valarm->REPEAT) ? (int) $valarm->REPEAT->getValue() : 0;
+		for ($i = 0; $i < $repeat; $i++) {
+			if ($valarm->DURATION === null) {
+				continue;
+			}
+
+			$clonedNotificationDate->add($valarm->DURATION->getDateInterval());
+			$alarms[] = [
+				'calendar_id' => $objectData['calendarid'],
+				'object_id' => $objectData['id'],
+				'uid' => (string) $valarm->parent->UID,
+				'is_recurring' => $isRecurring,
+				'recurrence_id' => $recurrenceId,
+				'is_recurrence_exception' => $isRecurrenceException,
+				'event_hash' => $eventHash,
+				'alarm_hash' => $alarmHash,
+				'type' => (string) $valarm->ACTION,
+				'is_relative' => $isRelative,
+				'notification_date' => $clonedNotificationDate->getTimestamp(),
+				'is_repeat_based' => true,
+			];
+		}
+
+		return $alarms;
+	}
+
+	/**
+	 * @param array $reminders
+	 */
+	private function writeRemindersToDatabase(array $reminders): void {
+		foreach ($reminders as $reminder) {
+			$this->backend->insertReminder(
+				(int) $reminder['calendar_id'],
+				(int) $reminder['object_id'],
+				$reminder['uid'],
+				$reminder['is_recurring'],
+				(int) $reminder['recurrence_id'],
+				$reminder['is_recurrence_exception'],
+				$reminder['event_hash'],
+				$reminder['alarm_hash'],
+				$reminder['type'],
+				$reminder['is_relative'],
+				(int) $reminder['notification_date'],
+				$reminder['is_repeat_based']
+			);
+		}
+	}
+
+	/**
+	 * @param array $reminder
+	 * @param VEvent $vevent
+	 */
+	private function deleteOrProcessNext(array $reminder,
+		VObject\Component\VEvent $vevent):void {
+		if ($reminder['is_repeat_based'] ||
+			!$reminder['is_recurring'] ||
+			!$reminder['is_relative'] ||
+			$reminder['is_recurrence_exception']) {
+			$this->backend->removeReminder($reminder['id']);
+			return;
+		}
+
+		$vevents = $this->getAllVEventsFromVCalendar($vevent->parent);
+		$recurrenceExceptions = $this->getRecurrenceExceptionFromListOfVEvents($vevents);
+		$now = $this->timeFactory->getDateTime();
+		$calendarTimeZone = $this->getCalendarTimeZone((int) $reminder['calendar_id']);
+
+		try {
+			$iterator = new EventIterator($vevents, $reminder['uid']);
+		} catch (NoInstancesException $e) {
+			// This event is recurring, but it doesn't have a single
+			// instance. We are skipping this event from the output
+			// entirely.
+			return;
+		}
+
+		try {
+			while ($iterator->valid()) {
+				$event = $iterator->getEventObject();
+
+				// Recurrence-exceptions are handled separately, so just ignore them here
+				if (\in_array($event, $recurrenceExceptions, true)) {
+					$iterator->next();
+					continue;
+				}
+
+				$recurrenceId = $this->getEffectiveRecurrenceIdOfVEvent($event);
+				if ($reminder['recurrence_id'] >= $recurrenceId) {
+					$iterator->next();
+					continue;
+				}
+
+				foreach ($event->VALARM as $valarm) {
+					/** @var VAlarm $valarm */
+					$alarmHash = $this->getAlarmHash($valarm);
+					if ($alarmHash !== $reminder['alarm_hash']) {
+						continue;
+					}
+
+					$triggerTime = $valarm->getEffectiveTriggerTime();
+
+					// If effective trigger time is in the past
+					// just skip and generate for next event
+					$diff = $now->diff($triggerTime);
+					if ($diff->invert === 1) {
+						continue;
+					}
+
+					$this->backend->removeReminder($reminder['id']);
+					$alarms = $this->getRemindersForVAlarm($valarm, [
+						'calendarid' => $reminder['calendar_id'],
+						'id' => $reminder['object_id'],
+					], $calendarTimeZone, $reminder['event_hash'], $alarmHash, true, false);
+					$this->writeRemindersToDatabase($alarms);
+
+					// Abort generating reminders after creating one successfully
+					return;
+				}
+
+				$iterator->next();
+			}
+		} catch (MaxInstancesExceededException $e) {
+			// Using debug logger as this isn't really an error
+			$this->logger->debug('Recurrence with too many instances detected, skipping VEVENT', ['exception' => $e]);
+		}
+
+		$this->backend->removeReminder($reminder['id']);
+	}
+
+	/**
+	 * @param int $calendarId
+	 * @return IUser[]
+	 */
+	private function getAllUsersWithWriteAccessToCalendar(int $calendarId):array {
+		$shares = $this->caldavBackend->getShares($calendarId);
+
+		$users = [];
+		$userIds = [];
+		$groups = [];
+		foreach ($shares as $share) {
+			// Only consider writable shares
+			if ($share['readOnly']) {
+				continue;
+			}
+
+			$principal = explode('/', $share['{http://owncloud.org/ns}principal']);
+			if ($principal[1] === 'users') {
+				$user = $this->userManager->get($principal[2]);
+				if ($user) {
+					$users[] = $user;
+					$userIds[] = $principal[2];
+				}
+			} elseif ($principal[1] === 'groups') {
+				$groups[] = $principal[2];
+			}
+		}
+
+		foreach ($groups as $gid) {
+			$group = $this->groupManager->get($gid);
+			if ($group instanceof IGroup) {
+				foreach ($group->getUsers() as $user) {
+					if (!\in_array($user->getUID(), $userIds, true)) {
+						$users[] = $user;
+						$userIds[] = $user->getUID();
+					}
+				}
+			}
+		}
+
+		return $users;
+	}
+
+	/**
+	 * Gets a hash of the event.
+	 * If the hash changes, we have to update all relative alarms.
+	 *
+	 * @param VEvent $vevent
+	 * @return string
+	 */
+	private function getEventHash(VEvent $vevent):string {
+		$properties = [
+			(string) $vevent->DTSTART->serialize(),
+		];
+
+		if ($vevent->DTEND) {
+			$properties[] = (string) $vevent->DTEND->serialize();
+		}
+		if ($vevent->DURATION) {
+			$properties[] = (string) $vevent->DURATION->serialize();
+		}
+		if ($vevent->{'RECURRENCE-ID'}) {
+			$properties[] = (string) $vevent->{'RECURRENCE-ID'}->serialize();
+		}
+		if ($vevent->RRULE) {
+			$properties[] = (string) $vevent->RRULE->serialize();
+		}
+		if ($vevent->EXDATE) {
+			$properties[] = (string) $vevent->EXDATE->serialize();
+		}
+		if ($vevent->RDATE) {
+			$properties[] = (string) $vevent->RDATE->serialize();
+		}
+
+		return md5(implode('::', $properties));
+	}
+
+	/**
+	 * Gets a hash of the alarm.
+	 * If the hash changes, we have to update oc_dav_reminders.
+	 *
+	 * @param VAlarm $valarm
+	 * @return string
+	 */
+	private function getAlarmHash(VAlarm $valarm):string {
+		$properties = [
+			(string) $valarm->ACTION->serialize(),
+			(string) $valarm->TRIGGER->serialize(),
+		];
+
+		if ($valarm->DURATION) {
+			$properties[] = (string) $valarm->DURATION->serialize();
+		}
+		if ($valarm->REPEAT) {
+			$properties[] = (string) $valarm->REPEAT->serialize();
+		}
+
+		return md5(implode('::', $properties));
+	}
+
+	/**
+	 * @param VObject\Component\VCalendar $vcalendar
+	 * @param int $recurrenceId
+	 * @param bool $isRecurrenceException
+	 * @return VEvent|null
+	 */
+	private function getVEventByRecurrenceId(VObject\Component\VCalendar $vcalendar,
+		int $recurrenceId,
+		bool $isRecurrenceException):?VEvent {
+		$vevents = $this->getAllVEventsFromVCalendar($vcalendar);
+		if (count($vevents) === 0) {
+			return null;
+		}
+
+		$uid = (string) $vevents[0]->UID;
+		$recurrenceExceptions = $this->getRecurrenceExceptionFromListOfVEvents($vevents);
+		$masterItem = $this->getMasterItemFromListOfVEvents($vevents);
+
+		// Handle recurrence-exceptions first, because recurrence-expansion is expensive
+		if ($isRecurrenceException) {
+			foreach ($recurrenceExceptions as $recurrenceException) {
+				if ($this->getEffectiveRecurrenceIdOfVEvent($recurrenceException) === $recurrenceId) {
+					return $recurrenceException;
+				}
+			}
+
+			return null;
+		}
+
+		if ($masterItem) {
+			try {
+				$iterator = new EventIterator($vevents, $uid);
+			} catch (NoInstancesException $e) {
+				// This event is recurring, but it doesn't have a single
+				// instance. We are skipping this event from the output
+				// entirely.
+				return null;
+			}
+
+			while ($iterator->valid()) {
+				$event = $iterator->getEventObject();
+
+				// Recurrence-exceptions are handled separately, so just ignore them here
+				if (\in_array($event, $recurrenceExceptions, true)) {
+					$iterator->next();
+					continue;
+				}
+
+				if ($this->getEffectiveRecurrenceIdOfVEvent($event) === $recurrenceId) {
+					return $event;
+				}
+
+				$iterator->next();
+			}
+		}
+
+		return null;
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return string
+	 */
+	private function getStatusOfEvent(VEvent $vevent):string {
+		if ($vevent->STATUS) {
+			return (string) $vevent->STATUS;
+		}
+
+		// Doesn't say so in the standard,
+		// but we consider events without a status
+		// to be confirmed
+		return 'CONFIRMED';
+	}
+
+	/**
+	 * @param VObject\Component\VEvent $vevent
+	 * @return bool
+	 */
+	private function wasEventCancelled(VObject\Component\VEvent $vevent):bool {
+		return $this->getStatusOfEvent($vevent) === 'CANCELLED';
+	}
+
+	/**
+	 * @param string $calendarData
+	 * @return VObject\Component\VCalendar|null
+	 */
+	private function parseCalendarData(string $calendarData):?VObject\Component\VCalendar {
+		try {
+			return VObject\Reader::read($calendarData,
+				VObject\Reader::OPTION_FORGIVING);
+		} catch (ParseException $ex) {
+			return null;
+		}
+	}
+
+	/**
+	 * @param string $principalUri
+	 * @return IUser|null
+	 */
+	private function getUserFromPrincipalURI(string $principalUri):?IUser {
+		if (!$principalUri) {
+			return null;
+		}
+
+		if (stripos($principalUri, 'principals/users/') !== 0) {
+			return null;
+		}
+
+		$userId = substr($principalUri, 17);
+		return $this->userManager->get($userId);
+	}
+
+	/**
+	 * @param VObject\Component\VCalendar $vcalendar
+	 * @return VObject\Component\VEvent[]
+	 */
+	private function getAllVEventsFromVCalendar(VObject\Component\VCalendar $vcalendar):array {
+		$vevents = [];
+
+		foreach ($vcalendar->children() as $child) {
+			if (!($child instanceof VObject\Component)) {
+				continue;
+			}
+
+			if ($child->name !== 'VEVENT') {
+				continue;
+			}
+			// Ignore invalid events with no DTSTART
+			if ($child->DTSTART === null) {
+				continue;
+			}
+
+			$vevents[] = $child;
+		}
+
+		return $vevents;
+	}
+
+	/**
+	 * @param array $vevents
+	 * @return VObject\Component\VEvent[]
+	 */
+	private function getRecurrenceExceptionFromListOfVEvents(array $vevents):array {
+		return array_values(array_filter($vevents, function (VEvent $vevent) {
+			return $vevent->{'RECURRENCE-ID'} !== null;
+		}));
+	}
+
+	/**
+	 * @param array $vevents
+	 * @return VEvent|null
+	 */
+	private function getMasterItemFromListOfVEvents(array $vevents):?VEvent {
+		$elements = array_values(array_filter($vevents, function (VEvent $vevent) {
+			return $vevent->{'RECURRENCE-ID'} === null;
+		}));
+
+		if (count($elements) === 0) {
+			return null;
+		}
+		if (count($elements) > 1) {
+			throw new \TypeError('Multiple master objects');
+		}
+
+		return $elements[0];
+	}
+
+	/**
+	 * @param VAlarm $valarm
+	 * @return bool
+	 */
+	private function isAlarmRelative(VAlarm $valarm):bool {
+		$trigger = $valarm->TRIGGER;
+		return $trigger instanceof VObject\Property\ICalendar\Duration;
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return int
+	 */
+	private function getEffectiveRecurrenceIdOfVEvent(VEvent $vevent):int {
+		if (isset($vevent->{'RECURRENCE-ID'})) {
+			return $vevent->{'RECURRENCE-ID'}->getDateTime()->getTimestamp();
+		}
+
+		return $vevent->DTSTART->getDateTime()->getTimestamp();
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return bool
+	 */
+	private function isRecurring(VEvent $vevent):bool {
+		return isset($vevent->RRULE) || isset($vevent->RDATE);
+	}
+
+	/**
+	 * @param int $calendarid
+	 *
+	 * @return DateTimeZone
+	 */
+	private function getCalendarTimeZone(int $calendarid): DateTimeZone {
+		$calendarInfo = $this->caldavBackend->getCalendarById($calendarid);
+		$tzProp = '{urn:ietf:params:xml:ns:caldav}calendar-timezone';
+		if (!isset($calendarInfo[$tzProp])) {
+			// Defaulting to UTC
+			return new DateTimeZone('UTC');
+		}
+		// This property contains a VCALENDAR with a single VTIMEZONE
+		/** @var string $timezoneProp */
+		$timezoneProp = $calendarInfo[$tzProp];
+		/** @var VObject\Component\VCalendar $vtimezoneObj */
+		$vtimezoneObj = VObject\Reader::read($timezoneProp);
+		/** @var VObject\Component\VTimeZone $vtimezone */
+		$vtimezone = $vtimezoneObj->VTIMEZONE;
+		return $vtimezone->getTimeZone();
+	}
+}