migrate therinaldos.com data

wedding-pics/apps/dav/lib/CalDAV/Schedule/IMipPlugin.php

@@ -0,0 +1,340 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016, ownCloud, Inc.
+ * @copyright Copyright (c) 2017, Georg Ehrke
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @copyright 2022 Anna Larch <anna.larch@gmx.net>
+ *
+ * @author brad2014 <brad2014@users.noreply.github.com>
+ * @author Brad Rubenstein <brad@wbr.tech>
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ * @author Joas Schilling <coding@schilljs.com>
+ * @author Leon Klingele <leon@struktur.de>
+ * @author Nick Sweeting <git@sweeting.me>
+ * @author rakekniven <mark.ziegler@rakekniven.de>
+ * @author Roeland Jago Douma <roeland@famdouma.nl>
+ * @author Thomas Citharel <nextcloud@tcit.fr>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ * @author Anna Larch <anna.larch@gmx.net>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * 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, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\DAV\CalDAV\Schedule;
+
+use OCA\DAV\CalDAV\CalendarObject;
+use OCA\DAV\CalDAV\EventComparisonService;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\Defaults;
+use OCP\IConfig;
+use OCP\IUserManager;
+use OCP\Mail\IMailer;
+use OCP\Util;
+use Psr\Log\LoggerInterface;
+use Sabre\CalDAV\Schedule\IMipPlugin as SabreIMipPlugin;
+use Sabre\DAV;
+use Sabre\DAV\INode;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Component\VEvent;
+use Sabre\VObject\ITip\Message;
+use Sabre\VObject\Parameter;
+use Sabre\VObject\Reader;
+
+/**
+ * iMIP handler.
+ *
+ * This class is responsible for sending out iMIP messages. iMIP is the
+ * email-based transport for iTIP. iTIP deals with scheduling operations for
+ * iCalendar objects.
+ *
+ * If you want to customize the email that gets sent out, you can do so by
+ * extending this class and overriding the sendMessage method.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class IMipPlugin extends SabreIMipPlugin {
+	private ?string $userId;
+	private IConfig $config;
+	private IMailer $mailer;
+	private LoggerInterface $logger;
+	private ITimeFactory $timeFactory;
+	private Defaults $defaults;
+	private IUserManager $userManager;
+	private ?VCalendar $vCalendar = null;
+	private IMipService $imipService;
+	public const MAX_DATE = '2038-01-01';
+	public const METHOD_REQUEST = 'request';
+	public const METHOD_REPLY = 'reply';
+	public const METHOD_CANCEL = 'cancel';
+	public const IMIP_INDENT = 15; // Enough for the length of all body bullet items, in all languages
+	private EventComparisonService $eventComparisonService;
+
+	public function __construct(IConfig $config,
+		IMailer $mailer,
+		LoggerInterface $logger,
+		ITimeFactory $timeFactory,
+		Defaults $defaults,
+		IUserManager $userManager,
+		$userId,
+		IMipService $imipService,
+		EventComparisonService $eventComparisonService) {
+		parent::__construct('');
+		$this->userId = $userId;
+		$this->config = $config;
+		$this->mailer = $mailer;
+		$this->logger = $logger;
+		$this->timeFactory = $timeFactory;
+		$this->defaults = $defaults;
+		$this->userManager = $userManager;
+		$this->imipService = $imipService;
+		$this->eventComparisonService = $eventComparisonService;
+	}
+
+	public function initialize(DAV\Server $server): void {
+		parent::initialize($server);
+		$server->on('beforeWriteContent', [$this, 'beforeWriteContent'], 10);
+	}
+
+	/**
+	 * Check quota before writing content
+	 *
+	 * @param string $uri target file URI
+	 * @param INode $node Sabre Node
+	 * @param resource $data data
+	 * @param bool $modified modified
+	 */
+	public function beforeWriteContent($uri, INode $node, $data, $modified): void {
+		if(!$node instanceof CalendarObject) {
+			return;
+		}
+		/** @var VCalendar $vCalendar */
+		$vCalendar = Reader::read($node->get());
+		$this->setVCalendar($vCalendar);
+	}
+
+	/**
+	 * Event handler for the 'schedule' event.
+	 *
+	 * @param Message $iTipMessage
+	 * @return void
+	 */
+	public function schedule(Message $iTipMessage) {
+		// Not sending any emails if the system considers the update
+		// insignificant.
+		if (!$iTipMessage->significantChange) {
+			if (!$iTipMessage->scheduleStatus) {
+				$iTipMessage->scheduleStatus = '1.0;We got the message, but it\'s not significant enough to warrant an email';
+			}
+			return;
+		}
+
+		if (parse_url($iTipMessage->sender, PHP_URL_SCHEME) !== 'mailto'
+			|| parse_url($iTipMessage->recipient, PHP_URL_SCHEME) !== 'mailto') {
+			return;
+		}
+
+		// don't send out mails for events that already took place
+		$lastOccurrence = $this->imipService->getLastOccurrence($iTipMessage->message);
+		$currentTime = $this->timeFactory->getTime();
+		if ($lastOccurrence < $currentTime) {
+			return;
+		}
+
+		// Strip off mailto:
+		$recipient = substr($iTipMessage->recipient, 7);
+		if (!$this->mailer->validateMailAddress($recipient)) {
+			// Nothing to send if the recipient doesn't have a valid email address
+			$iTipMessage->scheduleStatus = '5.0; EMail delivery failed';
+			return;
+		}
+		$recipientName = $iTipMessage->recipientName ? (string)$iTipMessage->recipientName : null;
+
+		$newEvents = $iTipMessage->message;
+		$oldEvents = $this->getVCalendar();
+
+		$modified = $this->eventComparisonService->findModified($newEvents, $oldEvents);
+		/** @var VEvent $vEvent */
+		$vEvent = array_pop($modified['new']);
+		/** @var VEvent $oldVevent */
+		$oldVevent = !empty($modified['old']) && is_array($modified['old']) ? array_pop($modified['old']) : null;
+		$isModified = isset($oldVevent);
+
+		// No changed events after all - this shouldn't happen if there is significant change yet here we are
+		// The scheduling status is debatable
+		if(empty($vEvent)) {
+			$this->logger->warning('iTip message said the change was significant but comparison did not detect any updated VEvents');
+			$iTipMessage->scheduleStatus = '1.0;We got the message, but it\'s not significant enough to warrant an email';
+			return;
+		}
+
+		// we (should) have one event component left
+		// as the ITip\Broker creates one iTip message per change
+		// and triggers the "schedule" event once per message
+		// we also might not have an old event as this could be a new
+		// invitation, or a new recurrence exception
+		$attendee = $this->imipService->getCurrentAttendee($iTipMessage);
+		if($attendee === null) {
+			$uid = $vEvent->UID ?? 'no UID found';
+			$this->logger->debug('Could not find recipient ' . $recipient . ' as attendee for event with UID ' . $uid);
+			$iTipMessage->scheduleStatus = '5.0; EMail delivery failed';
+			return;
+		}
+		// Don't send emails to things
+		if($this->imipService->isRoomOrResource($attendee)) {
+			$this->logger->debug('No invitation sent as recipient is room or resource', [
+				'attendee' => $recipient,
+			]);
+			$iTipMessage->scheduleStatus = '1.0;We got the message, but it\'s not significant enough to warrant an email';
+			return;
+		}
+		$this->imipService->setL10n($attendee);
+
+		// Build the sender name.
+		// Due to a bug in sabre, the senderName property for an iTIP message
+		// can actually also be a VObject Property
+		/** @var Parameter|string|null $senderName */
+		$senderName = $iTipMessage->senderName ?: null;
+		if($senderName instanceof Parameter) {
+			$senderName = $senderName->getValue() ?? null;
+		}
+
+		// Try to get the sender name from the current user id if available.
+		if ($this->userId !== null && ($senderName === null || empty(trim($senderName)))) {
+			$senderName = $this->userManager->getDisplayName($this->userId);
+		}
+
+		$sender = substr($iTipMessage->sender, 7);
+
+		$replyingAttendee = null;
+		switch (strtolower($iTipMessage->method)) {
+			case self::METHOD_REPLY:
+				$method = self::METHOD_REPLY;
+				$data = $this->imipService->buildBodyData($vEvent, $oldVevent);
+				$replyingAttendee = $this->imipService->getReplyingAttendee($iTipMessage);
+				break;
+			case self::METHOD_CANCEL:
+				$method = self::METHOD_CANCEL;
+				$data = $this->imipService->buildCancelledBodyData($vEvent);
+				break;
+			default:
+				$method = self::METHOD_REQUEST;
+				$data = $this->imipService->buildBodyData($vEvent, $oldVevent);
+				break;
+		}
+
+		$data['attendee_name'] = ($recipientName ?: $recipient);
+		$data['invitee_name'] = ($senderName ?: $sender);
+
+		$fromEMail = Util::getDefaultEmailAddress('invitations-noreply');
+		$fromName = $this->imipService->getFrom($senderName, $this->defaults->getName());
+
+		$message = $this->mailer->createMessage()
+			->setFrom([$fromEMail => $fromName]);
+
+		if ($recipientName !== null) {
+			$message->setTo([$recipient => $recipientName]);
+		} else {
+			$message->setTo([$recipient]);
+		}
+
+		if ($senderName !== null) {
+			$message->setReplyTo([$sender => $senderName]);
+		} else {
+			$message->setReplyTo([$sender]);
+		}
+
+		$template = $this->mailer->createEMailTemplate('dav.calendarInvite.' . $method, $data);
+		$template->addHeader();
+
+		$this->imipService->addSubjectAndHeading($template, $method, $data['invitee_name'], $data['meeting_title'], $isModified, $replyingAttendee);
+		$this->imipService->addBulletList($template, $vEvent, $data);
+
+		// Only add response buttons to invitation requests: Fix Issue #11230
+		if (strcasecmp($method, self::METHOD_REQUEST) === 0 && $this->imipService->getAttendeeRsvpOrReqForParticipant($attendee)) {
+
+			/*
+			** Only offer invitation accept/reject buttons, which link back to the
+			** nextcloud server, to recipients who can access the nextcloud server via
+			** their internet/intranet.  Issue #12156
+			**
+			** The app setting is stored in the appconfig database table.
+			**
+			** For nextcloud servers accessible to the public internet, the default
+			** "invitation_link_recipients" value "yes" (all recipients) is appropriate.
+			**
+			** When the nextcloud server is restricted behind a firewall, accessible
+			** only via an internal network or via vpn, you can set "dav.invitation_link_recipients"
+			** to the email address or email domain, or comma separated list of addresses or domains,
+			** of recipients who can access the server.
+			**
+			** To always deliver URLs, set invitation_link_recipients to "yes".
+			** To suppress URLs entirely, set invitation_link_recipients to boolean "no".
+			*/
+
+			$recipientDomain = substr(strrchr($recipient, '@'), 1);
+			$invitationLinkRecipients = explode(',', preg_replace('/\s+/', '', strtolower($this->config->getAppValue('dav', 'invitation_link_recipients', 'yes'))));
+
+			if (strcmp('yes', $invitationLinkRecipients[0]) === 0
+				|| in_array(strtolower($recipient), $invitationLinkRecipients)
+				|| in_array(strtolower($recipientDomain), $invitationLinkRecipients)) {
+				$token = $this->imipService->createInvitationToken($iTipMessage, $vEvent, $lastOccurrence);
+				$this->imipService->addResponseButtons($template, $token);
+				$this->imipService->addMoreOptionsButton($template, $token);
+			}
+		}
+
+		$template->addFooter();
+
+		$message->useTemplate($template);
+
+		$itip_msg = $iTipMessage->message->serialize();
+		$message->attachInline(
+			$itip_msg,
+			'event.ics',
+			'text/calendar; method=' . $iTipMessage->method,
+		);
+
+		try {
+			$failed = $this->mailer->send($message);
+			$iTipMessage->scheduleStatus = '1.1; Scheduling message is sent via iMip';
+			if (!empty($failed)) {
+				$this->logger->error('Unable to deliver message to {failed}', ['app' => 'dav', 'failed' => implode(', ', $failed)]);
+				$iTipMessage->scheduleStatus = '5.0; EMail delivery failed';
+			}
+		} catch (\Exception $ex) {
+			$this->logger->error($ex->getMessage(), ['app' => 'dav', 'exception' => $ex]);
+			$iTipMessage->scheduleStatus = '5.0; EMail delivery failed';
+		}
+	}
+
+	/**
+	 * @return ?VCalendar
+	 */
+	public function getVCalendar(): ?VCalendar {
+		return $this->vCalendar;
+	}
+
+	/**
+	 * @param ?VCalendar $vCalendar
+	 */
+	public function setVCalendar(?VCalendar $vCalendar): void {
+		$this->vCalendar = $vCalendar;
+	}
+
+}

wedding-pics/apps/dav/lib/CalDAV/Schedule/IMipService.php

@@ -0,0 +1,691 @@
+<?php
+
+declare(strict_types=1);
+/*
+ * DAV App
+ *
+ * @copyright 2022 Anna Larch <anna.larch@gmx.net>
+ *
+ * @author Anna Larch <anna.larch@gmx.net>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
+ * License as published by the Free Software Foundation; either
+ * version 3 of the License, or any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU AFFERO GENERAL PUBLIC LICENSE for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public
+ * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace OCA\DAV\CalDAV\Schedule;
+
+use OC\URLGenerator;
+use OCP\IConfig;
+use OCP\IDBConnection;
+use OCP\IL10N;
+use OCP\L10N\IFactory as L10NFactory;
+use OCP\Mail\IEMailTemplate;
+use OCP\Security\ISecureRandom;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Component\VEvent;
+use Sabre\VObject\DateTimeParser;
+use Sabre\VObject\ITip\Message;
+use Sabre\VObject\Parameter;
+use Sabre\VObject\Property;
+use Sabre\VObject\Recur\EventIterator;
+
+class IMipService {
+
+	private URLGenerator $urlGenerator;
+	private IConfig $config;
+	private IDBConnection $db;
+	private ISecureRandom $random;
+	private L10NFactory $l10nFactory;
+	private IL10N $l10n;
+
+	/** @var string[] */
+	private const STRING_DIFF = [
+		'meeting_title' => 'SUMMARY',
+		'meeting_description' => 'DESCRIPTION',
+		'meeting_url' => 'URL',
+		'meeting_location' => 'LOCATION'
+	];
+
+	public function __construct(URLGenerator $urlGenerator,
+		IConfig $config,
+		IDBConnection $db,
+		ISecureRandom $random,
+		L10NFactory $l10nFactory) {
+		$this->urlGenerator = $urlGenerator;
+		$this->config = $config;
+		$this->db = $db;
+		$this->random = $random;
+		$this->l10nFactory = $l10nFactory;
+		$default = $this->l10nFactory->findGenericLanguage();
+		$this->l10n = $this->l10nFactory->get('dav', $default);
+	}
+
+	/**
+	 * @param string|null $senderName
+	 * @param string $default
+	 * @return string
+	 */
+	public function getFrom(?string $senderName, string $default): string {
+		if ($senderName === null) {
+			return $default;
+		}
+
+		return $this->l10n->t('%1$s via %2$s', [$senderName, $default]);
+	}
+
+	public static function readPropertyWithDefault(VEvent $vevent, string $property, string $default) {
+		if (isset($vevent->$property)) {
+			$value = $vevent->$property->getValue();
+			if (!empty($value)) {
+				return $value;
+			}
+		}
+		return $default;
+	}
+
+	private function generateDiffString(VEvent $vevent, VEvent $oldVEvent, string $property, string $default): ?string {
+		$strikethrough = "<span style='text-decoration: line-through'>%s</span><br />%s";
+		if (!isset($vevent->$property)) {
+			return $default;
+		}
+		$newstring = $vevent->$property->getValue();
+		if(isset($oldVEvent->$property) && $oldVEvent->$property->getValue() !== $newstring) {
+			$oldstring = $oldVEvent->$property->getValue();
+			return sprintf($strikethrough, $oldstring, $newstring);
+		}
+		return $newstring;
+	}
+
+	/**
+	 * Like generateDiffString() but linkifies the property values if they are urls.
+	 */
+	private function generateLinkifiedDiffString(VEvent $vevent, VEvent $oldVEvent, string $property, string $default): ?string {
+		if (!isset($vevent->$property)) {
+			return $default;
+		}
+		/** @var string|null $newString */
+		$newString = $vevent->$property->getValue();
+		$oldString = isset($oldVEvent->$property) ? $oldVEvent->$property->getValue() : null;
+		if ($oldString !== $newString) {
+			return sprintf(
+				"<span style='text-decoration: line-through'>%s</span><br />%s",
+				$this->linkify($oldString) ?? $oldString ?? '',
+				$this->linkify($newString) ?? $newString ?? ''
+			);
+		}
+		return $this->linkify($newString) ?? $newString;
+	}
+
+	/**
+	 * Convert a given url to a html link element or return null otherwise.
+	 */
+	private function linkify(?string $url): ?string {
+		if ($url === null) {
+			return null;
+		}
+		if (!str_starts_with($url, 'http://') && !str_starts_with($url, 'https://')) {
+			return null;
+		}
+
+		return sprintf('<a href="%1$s">%1$s</a>', htmlspecialchars($url));
+	}
+
+	/**
+	 * @param VEvent $vEvent
+	 * @param VEvent|null $oldVEvent
+	 * @return array
+	 */
+	public function buildBodyData(VEvent $vEvent, ?VEvent $oldVEvent): array {
+		$defaultVal = '';
+		$data = [];
+		$data['meeting_when'] = $this->generateWhenString($vEvent);
+
+		foreach(self::STRING_DIFF as $key => $property) {
+			$data[$key] = self::readPropertyWithDefault($vEvent, $property, $defaultVal);
+		}
+
+		$data['meeting_url_html'] = self::readPropertyWithDefault($vEvent, 'URL', $defaultVal);
+
+		if (($locationHtml = $this->linkify($data['meeting_location'])) !== null) {
+			$data['meeting_location_html'] = $locationHtml;
+		}
+
+		if(!empty($oldVEvent)) {
+			$oldMeetingWhen = $this->generateWhenString($oldVEvent);
+			$data['meeting_title_html'] = $this->generateDiffString($vEvent, $oldVEvent, 'SUMMARY', $data['meeting_title']);
+			$data['meeting_description_html'] = $this->generateDiffString($vEvent, $oldVEvent, 'DESCRIPTION', $data['meeting_description']);
+			$data['meeting_location_html'] = $this->generateLinkifiedDiffString($vEvent, $oldVEvent, 'LOCATION', $data['meeting_location']);
+
+			$oldUrl = self::readPropertyWithDefault($oldVEvent, 'URL', $defaultVal);
+			$data['meeting_url_html'] = !empty($oldUrl) && $oldUrl !== $data['meeting_url'] ? sprintf('<a href="%1$s">%1$s</a>', $oldUrl) : $data['meeting_url'];
+
+			$data['meeting_when_html'] =
+				($oldMeetingWhen !== $data['meeting_when'] && $oldMeetingWhen !== null)
+					? sprintf("<span style='text-decoration: line-through'>%s</span><br />%s", $oldMeetingWhen, $data['meeting_when'])
+					: $data['meeting_when'];
+		}
+		return $data;
+	}
+
+	/**
+	 * @param IL10N $this->l10n
+	 * @param VEvent $vevent
+	 * @return false|int|string
+	 */
+	public function generateWhenString(VEvent $vevent) {
+		/** @var Property\ICalendar\DateTime $dtstart */
+		$dtstart = $vevent->DTSTART;
+		if (isset($vevent->DTEND)) {
+			/** @var Property\ICalendar\DateTime $dtend */
+			$dtend = $vevent->DTEND;
+		} elseif (isset($vevent->DURATION)) {
+			$isFloating = $dtstart->isFloating();
+			$dtend = clone $dtstart;
+			$endDateTime = $dtend->getDateTime();
+			$endDateTime = $endDateTime->add(DateTimeParser::parse($vevent->DURATION->getValue()));
+			$dtend->setDateTime($endDateTime, $isFloating);
+		} elseif (!$dtstart->hasTime()) {
+			$isFloating = $dtstart->isFloating();
+			$dtend = clone $dtstart;
+			$endDateTime = $dtend->getDateTime();
+			$endDateTime = $endDateTime->modify('+1 day');
+			$dtend->setDateTime($endDateTime, $isFloating);
+		} else {
+			$dtend = clone $dtstart;
+		}
+
+		/** @var Property\ICalendar\Date | Property\ICalendar\DateTime $dtstart */
+		/** @var \DateTimeImmutable $dtstartDt */
+		$dtstartDt = $dtstart->getDateTime();
+
+		/** @var Property\ICalendar\Date | Property\ICalendar\DateTime $dtend */
+		/** @var \DateTimeImmutable $dtendDt */
+		$dtendDt = $dtend->getDateTime();
+
+		$diff = $dtstartDt->diff($dtendDt);
+
+		$dtstartDt = new \DateTime($dtstartDt->format(\DateTimeInterface::ATOM));
+		$dtendDt = new \DateTime($dtendDt->format(\DateTimeInterface::ATOM));
+
+		if ($dtstart instanceof Property\ICalendar\Date) {
+			// One day event
+			if ($diff->days === 1) {
+				return $this->l10n->l('date', $dtstartDt, ['width' => 'medium']);
+			}
+
+			// DTEND is exclusive, so if the ics data says 2020-01-01 to 2020-01-05,
+			// the email should show 2020-01-01 to 2020-01-04.
+			$dtendDt->modify('-1 day');
+
+			//event that spans over multiple days
+			$localeStart = $this->l10n->l('date', $dtstartDt, ['width' => 'medium']);
+			$localeEnd = $this->l10n->l('date', $dtendDt, ['width' => 'medium']);
+
+			return $localeStart . ' - ' . $localeEnd;
+		}
+
+		/** @var Property\ICalendar\DateTime $dtstart */
+		/** @var Property\ICalendar\DateTime $dtend */
+		$isFloating = $dtstart->isFloating();
+		$startTimezone = $endTimezone = null;
+		if (!$isFloating) {
+			$prop = $dtstart->offsetGet('TZID');
+			if ($prop instanceof Parameter) {
+				$startTimezone = $prop->getValue();
+			}
+
+			$prop = $dtend->offsetGet('TZID');
+			if ($prop instanceof Parameter) {
+				$endTimezone = $prop->getValue();
+			}
+		}
+
+		$localeStart = $this->l10n->l('weekdayName', $dtstartDt, ['width' => 'abbreviated']) . ', ' .
+			$this->l10n->l('datetime', $dtstartDt, ['width' => 'medium|short']);
+
+		// always show full date with timezone if timezones are different
+		if ($startTimezone !== $endTimezone) {
+			$localeEnd = $this->l10n->l('datetime', $dtendDt, ['width' => 'medium|short']);
+
+			return $localeStart . ' (' . $startTimezone . ') - ' .
+				$localeEnd . ' (' . $endTimezone . ')';
+		}
+
+		// show only end time if date is the same
+		if ($dtstartDt->format('Y-m-d') === $dtendDt->format('Y-m-d')) {
+			$localeEnd = $this->l10n->l('time', $dtendDt, ['width' => 'short']);
+		} else {
+			$localeEnd = $this->l10n->l('weekdayName', $dtendDt, ['width' => 'abbreviated']) . ', ' .
+				$this->l10n->l('datetime', $dtendDt, ['width' => 'medium|short']);
+		}
+
+		return $localeStart . ' - ' . $localeEnd . ' (' . $startTimezone . ')';
+	}
+
+	/**
+	 * @param VEvent $vEvent
+	 * @return array
+	 */
+	public function buildCancelledBodyData(VEvent $vEvent): array {
+		$defaultVal = '';
+		$strikethrough = "<span style='text-decoration: line-through'>%s</span>";
+
+		$newMeetingWhen = $this->generateWhenString($vEvent);
+		$newSummary = isset($vEvent->SUMMARY) && (string)$vEvent->SUMMARY !== '' ? (string)$vEvent->SUMMARY : $this->l10n->t('Untitled event');
+		;
+		$newDescription = isset($vEvent->DESCRIPTION) && (string)$vEvent->DESCRIPTION !== '' ? (string)$vEvent->DESCRIPTION : $defaultVal;
+		$newUrl = isset($vEvent->URL) && (string)$vEvent->URL !== '' ? sprintf('<a href="%1$s">%1$s</a>', $vEvent->URL) : $defaultVal;
+		$newLocation = isset($vEvent->LOCATION) && (string)$vEvent->LOCATION !== '' ? (string)$vEvent->LOCATION : $defaultVal;
+		$newLocationHtml = $this->linkify($newLocation) ?? $newLocation;
+
+		$data = [];
+		$data['meeting_when_html'] = $newMeetingWhen === '' ?: sprintf($strikethrough, $newMeetingWhen);
+		$data['meeting_when'] = $newMeetingWhen;
+		$data['meeting_title_html'] = sprintf($strikethrough, $newSummary);
+		$data['meeting_title'] = $newSummary !== '' ? $newSummary: $this->l10n->t('Untitled event');
+		$data['meeting_description_html'] = $newDescription !== '' ? sprintf($strikethrough, $newDescription) : '';
+		$data['meeting_description'] = $newDescription;
+		$data['meeting_url_html'] = $newUrl !== '' ? sprintf($strikethrough, $newUrl) : '';
+		$data['meeting_url'] = isset($vEvent->URL) ? (string)$vEvent->URL : '';
+		$data['meeting_location_html'] = $newLocationHtml !== '' ? sprintf($strikethrough, $newLocationHtml) : '';
+		$data['meeting_location'] = $newLocation;
+		return $data;
+	}
+
+	/**
+	 * Check if event took place in the past
+	 *
+	 * @param VCalendar $vObject
+	 * @return int
+	 */
+	public function getLastOccurrence(VCalendar $vObject) {
+		/** @var VEvent $component */
+		$component = $vObject->VEVENT;
+
+		if (isset($component->RRULE)) {
+			$it = new EventIterator($vObject, (string)$component->UID);
+			$maxDate = new \DateTime(IMipPlugin::MAX_DATE);
+			if ($it->isInfinite()) {
+				return $maxDate->getTimestamp();
+			}
+
+			$end = $it->getDtEnd();
+			while ($it->valid() && $end < $maxDate) {
+				$end = $it->getDtEnd();
+				$it->next();
+			}
+			return $end->getTimestamp();
+		}
+
+		/** @var Property\ICalendar\DateTime $dtStart */
+		$dtStart = $component->DTSTART;
+
+		if (isset($component->DTEND)) {
+			/** @var Property\ICalendar\DateTime $dtEnd */
+			$dtEnd = $component->DTEND;
+			return $dtEnd->getDateTime()->getTimeStamp();
+		}
+
+		if(isset($component->DURATION)) {
+			/** @var \DateTime $endDate */
+			$endDate = clone $dtStart->getDateTime();
+			// $component->DTEND->getDateTime() returns DateTimeImmutable
+			$endDate = $endDate->add(DateTimeParser::parse($component->DURATION->getValue()));
+			return $endDate->getTimestamp();
+		}
+
+		if(!$dtStart->hasTime()) {
+			/** @var \DateTime $endDate */
+			// $component->DTSTART->getDateTime() returns DateTimeImmutable
+			$endDate = clone $dtStart->getDateTime();
+			$endDate = $endDate->modify('+1 day');
+			return $endDate->getTimestamp();
+		}
+
+		// No computation of end time possible - return start date
+		return $dtStart->getDateTime()->getTimeStamp();
+	}
+
+	/**
+	 * @param Property|null $attendee
+	 */
+	public function setL10n(?Property $attendee = null) {
+		if($attendee === null) {
+			return;
+		}
+
+		$lang = $attendee->offsetGet('LANGUAGE');
+		if ($lang instanceof Parameter) {
+			$lang = $lang->getValue();
+			$this->l10n = $this->l10nFactory->get('dav', $lang);
+		}
+	}
+
+	/**
+	 * @param Property|null $attendee
+	 * @return bool
+	 */
+	public function getAttendeeRsvpOrReqForParticipant(?Property $attendee = null) {
+		if($attendee === null) {
+			return false;
+		}
+
+		$rsvp = $attendee->offsetGet('RSVP');
+		if (($rsvp instanceof Parameter) && (strcasecmp($rsvp->getValue(), 'TRUE') === 0)) {
+			return true;
+		}
+		$role = $attendee->offsetGet('ROLE');
+		// @see https://datatracker.ietf.org/doc/html/rfc5545#section-3.2.16
+		// Attendees without a role are assumed required and should receive an invitation link even if they have no RSVP set
+		if ($role === null
+			|| (($role instanceof Parameter) && (strcasecmp($role->getValue(), 'REQ-PARTICIPANT') === 0))
+			|| (($role instanceof Parameter) && (strcasecmp($role->getValue(), 'OPT-PARTICIPANT') === 0))
+		) {
+			return true;
+		}
+
+		// RFC 5545 3.2.17: default RSVP is false
+		return false;
+	}
+
+	/**
+	 * @param IEMailTemplate $template
+	 * @param string $method
+	 * @param string $sender
+	 * @param string $summary
+	 * @param string|null $partstat
+	 * @param bool $isModified
+	 */
+	public function addSubjectAndHeading(IEMailTemplate $template,
+		string $method, string $sender, string $summary, bool $isModified, ?Property $replyingAttendee = null): void {
+		if ($method === IMipPlugin::METHOD_CANCEL) {
+			// TRANSLATORS Subject for email, when an invitation is cancelled. Ex: "Cancelled: {{Event Name}}"
+			$template->setSubject($this->l10n->t('Cancelled: %1$s', [$summary]));
+			$template->addHeading($this->l10n->t('"%1$s" has been canceled', [$summary]));
+		} elseif ($method === IMipPlugin::METHOD_REPLY) {
+			// TRANSLATORS Subject for email, when an invitation is replied to. Ex: "Re: {{Event Name}}"
+			$template->setSubject($this->l10n->t('Re: %1$s', [$summary]));
+			// Build the strings
+			$partstat = (isset($replyingAttendee)) ? $replyingAttendee->offsetGet('PARTSTAT') : null;
+			$partstat = ($partstat instanceof Parameter) ? $partstat->getValue() : null;
+			switch ($partstat) {
+				case 'ACCEPTED':
+					$template->addHeading($this->l10n->t('%1$s has accepted your invitation', [$sender]));
+					break;
+				case 'TENTATIVE':
+					$template->addHeading($this->l10n->t('%1$s has tentatively accepted your invitation', [$sender]));
+					break;
+				case 'DECLINED':
+					$template->addHeading($this->l10n->t('%1$s has declined your invitation', [$sender]));
+					break;
+				case null:
+				default:
+					$template->addHeading($this->l10n->t('%1$s has responded to your invitation', [$sender]));
+					break;
+			}
+		} elseif ($method === IMipPlugin::METHOD_REQUEST && $isModified) {
+			// TRANSLATORS Subject for email, when an invitation is updated. Ex: "Invitation updated: {{Event Name}}"
+			$template->setSubject($this->l10n->t('Invitation updated: %1$s', [$summary]));
+			$template->addHeading($this->l10n->t('%1$s updated the event "%2$s"', [$sender, $summary]));
+		} else {
+			// TRANSLATORS Subject for email, when an invitation is sent. Ex: "Invitation: {{Event Name}}"
+			$template->setSubject($this->l10n->t('Invitation: %1$s', [$summary]));
+			$template->addHeading($this->l10n->t('%1$s would like to invite you to "%2$s"', [$sender, $summary]));
+		}
+	}
+
+	/**
+	 * @param string $path
+	 * @return string
+	 */
+	public function getAbsoluteImagePath($path): string {
+		return $this->urlGenerator->getAbsoluteURL(
+			$this->urlGenerator->imagePath('core', $path)
+		);
+	}
+
+	/**
+	 * addAttendees: add organizer and attendee names/emails to iMip mail.
+	 *
+	 * Enable with DAV setting: invitation_list_attendees (default: no)
+	 *
+	 * The default is 'no', which matches old behavior, and is privacy preserving.
+	 *
+	 * To enable including attendees in invitation emails:
+	 *   % php occ config:app:set dav invitation_list_attendees --value yes
+	 *
+	 * @param IEMailTemplate $template
+	 * @param IL10N $this->l10n
+	 * @param VEvent $vevent
+	 * @author brad2014 on github.com
+	 */
+	public function addAttendees(IEMailTemplate $template, VEvent $vevent) {
+		if ($this->config->getAppValue('dav', 'invitation_list_attendees', 'no') === 'no') {
+			return;
+		}
+
+		if (isset($vevent->ORGANIZER)) {
+			/** @var Property | Property\ICalendar\CalAddress $organizer */
+			$organizer = $vevent->ORGANIZER;
+			$organizerEmail = substr($organizer->getNormalizedValue(), 7);
+			/** @var string|null $organizerName */
+			$organizerName = isset($organizer->CN) ? $organizer->CN->getValue() : null;
+			$organizerHTML = sprintf('<a href="%s">%s</a>',
+				htmlspecialchars($organizer->getNormalizedValue()),
+				htmlspecialchars($organizerName ?: $organizerEmail));
+			$organizerText = sprintf('%s <%s>', $organizerName, $organizerEmail);
+			if(isset($organizer['PARTSTAT'])) {
+				/** @var Parameter $partstat */
+				$partstat = $organizer['PARTSTAT'];
+				if(strcasecmp($partstat->getValue(), 'ACCEPTED') === 0) {
+					$organizerHTML .= ' ✔︎';
+					$organizerText .= ' ✔︎';
+				}
+			}
+			$template->addBodyListItem($organizerHTML, $this->l10n->t('Organizer:'),
+				$this->getAbsoluteImagePath('caldav/organizer.png'),
+				$organizerText, '', IMipPlugin::IMIP_INDENT);
+		}
+
+		$attendees = $vevent->select('ATTENDEE');
+		if (count($attendees) === 0) {
+			return;
+		}
+
+		$attendeesHTML = [];
+		$attendeesText = [];
+		foreach ($attendees as $attendee) {
+			$attendeeEmail = substr($attendee->getNormalizedValue(), 7);
+			$attendeeName = isset($attendee['CN']) ? $attendee['CN']->getValue() : null;
+			$attendeeHTML = sprintf('<a href="%s">%s</a>',
+				htmlspecialchars($attendee->getNormalizedValue()),
+				htmlspecialchars($attendeeName ?: $attendeeEmail));
+			$attendeeText = sprintf('%s <%s>', $attendeeName, $attendeeEmail);
+			if (isset($attendee['PARTSTAT'])) {
+				/** @var Parameter $partstat */
+				$partstat = $attendee['PARTSTAT'];
+				if (strcasecmp($partstat->getValue(), 'ACCEPTED') === 0) {
+					$attendeeHTML .= ' ✔︎';
+					$attendeeText .= ' ✔︎';
+				}
+			}
+			$attendeesHTML[] = $attendeeHTML;
+			$attendeesText[] = $attendeeText;
+		}
+
+		$template->addBodyListItem(implode('<br/>', $attendeesHTML), $this->l10n->t('Attendees:'),
+			$this->getAbsoluteImagePath('caldav/attendees.png'),
+			implode("\n", $attendeesText), '', IMipPlugin::IMIP_INDENT);
+	}
+
+	/**
+	 * @param IEMailTemplate $template
+	 * @param VEVENT $vevent
+	 * @param $data
+	 */
+	public function addBulletList(IEMailTemplate $template, VEvent $vevent, $data) {
+		$template->addBodyListItem(
+			$data['meeting_title_html'] ?? $data['meeting_title'], $this->l10n->t('Title:'),
+			$this->getAbsoluteImagePath('caldav/title.png'), $data['meeting_title'], '', IMipPlugin::IMIP_INDENT);
+		if ($data['meeting_when'] !== '') {
+			$template->addBodyListItem($data['meeting_when_html'] ?? $data['meeting_when'], $this->l10n->t('Time:'),
+				$this->getAbsoluteImagePath('caldav/time.png'), $data['meeting_when'], '', IMipPlugin::IMIP_INDENT);
+		}
+		if ($data['meeting_location'] !== '') {
+			$template->addBodyListItem($data['meeting_location_html'] ?? $data['meeting_location'], $this->l10n->t('Location:'),
+				$this->getAbsoluteImagePath('caldav/location.png'), $data['meeting_location'], '', IMipPlugin::IMIP_INDENT);
+		}
+		if ($data['meeting_url'] !== '') {
+			$template->addBodyListItem($data['meeting_url_html'] ?? $data['meeting_url'], $this->l10n->t('Link:'),
+				$this->getAbsoluteImagePath('caldav/link.png'), $data['meeting_url'], '', IMipPlugin::IMIP_INDENT);
+		}
+
+		$this->addAttendees($template, $vevent);
+
+		/* Put description last, like an email body, since it can be arbitrarily long */
+		if ($data['meeting_description']) {
+			$template->addBodyListItem($data['meeting_description_html'] ?? $data['meeting_description'], $this->l10n->t('Description:'),
+				$this->getAbsoluteImagePath('caldav/description.png'), $data['meeting_description'], '', IMipPlugin::IMIP_INDENT);
+		}
+	}
+
+	/**
+	 * @param Message $iTipMessage
+	 * @return null|Property
+	 */
+	public function getCurrentAttendee(Message $iTipMessage): ?Property {
+		/** @var VEvent $vevent */
+		$vevent = $iTipMessage->message->VEVENT;
+		$attendees = $vevent->select('ATTENDEE');
+		foreach ($attendees as $attendee) {
+			/** @var Property $attendee */
+			if (strcasecmp($attendee->getValue(), $iTipMessage->recipient) === 0) {
+				return $attendee;
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * @param Message $iTipMessage
+	 * @param VEvent $vevent
+	 * @param int $lastOccurrence
+	 * @return string
+	 */
+	public function createInvitationToken(Message $iTipMessage, VEvent $vevent, int $lastOccurrence): string {
+		$token = $this->random->generate(60, ISecureRandom::CHAR_ALPHANUMERIC);
+
+		$attendee = $iTipMessage->recipient;
+		$organizer = $iTipMessage->sender;
+		$sequence = $iTipMessage->sequence;
+		$recurrenceId = isset($vevent->{'RECURRENCE-ID'}) ?
+			$vevent->{'RECURRENCE-ID'}->serialize() : null;
+		$uid = $vevent->{'UID'};
+
+		$query = $this->db->getQueryBuilder();
+		$query->insert('calendar_invitations')
+			->values([
+				'token' => $query->createNamedParameter($token),
+				'attendee' => $query->createNamedParameter($attendee),
+				'organizer' => $query->createNamedParameter($organizer),
+				'sequence' => $query->createNamedParameter($sequence),
+				'recurrenceid' => $query->createNamedParameter($recurrenceId),
+				'expiration' => $query->createNamedParameter($lastOccurrence),
+				'uid' => $query->createNamedParameter($uid)
+			])
+			->execute();
+
+		return $token;
+	}
+
+	/**
+	 * Create a valid VCalendar object out of the details of
+	 * a VEvent and its associated iTip Message
+	 *
+	 * We do this to filter out all unchanged VEvents
+	 * This is especially important in iTip Messages with recurrences
+	 * and recurrence exceptions
+	 *
+	 * @param Message $iTipMessage
+	 * @param VEvent $vEvent
+	 * @return VCalendar
+	 */
+	public function generateVCalendar(Message $iTipMessage, VEvent $vEvent): VCalendar {
+		$vCalendar = new VCalendar();
+		$vCalendar->add('METHOD', $iTipMessage->method);
+		foreach ($iTipMessage->message->getComponents() as $component) {
+			if ($component instanceof VEvent) {
+				continue;
+			}
+			$vCalendar->add(clone $component);
+		}
+		$vCalendar->add($vEvent);
+		return $vCalendar;
+	}
+
+	/**
+	 * @param IEMailTemplate $template
+	 * @param $token
+	 */
+	public function addResponseButtons(IEMailTemplate $template, $token) {
+		$template->addBodyButtonGroup(
+			$this->l10n->t('Accept'),
+			$this->urlGenerator->linkToRouteAbsolute('dav.invitation_response.accept', [
+				'token' => $token,
+			]),
+			$this->l10n->t('Decline'),
+			$this->urlGenerator->linkToRouteAbsolute('dav.invitation_response.decline', [
+				'token' => $token,
+			])
+		);
+	}
+
+	public function addMoreOptionsButton(IEMailTemplate $template, $token) {
+		$moreOptionsURL = $this->urlGenerator->linkToRouteAbsolute('dav.invitation_response.options', [
+			'token' => $token,
+		]);
+		$html = vsprintf('<small><a href="%s">%s</a></small>', [
+			$moreOptionsURL, $this->l10n->t('More options …')
+		]);
+		$text = $this->l10n->t('More options at %s', [$moreOptionsURL]);
+
+		$template->addBodyText($html, $text);
+	}
+
+	public function getReplyingAttendee(Message $iTipMessage): ?Property {
+		/** @var VEvent $vevent */
+		$vevent = $iTipMessage->message->VEVENT;
+		$attendees = $vevent->select('ATTENDEE');
+		foreach ($attendees as $attendee) {
+			/** @var Property $attendee */
+			if (strcasecmp($attendee->getValue(), $iTipMessage->sender) === 0) {
+				return $attendee;
+			}
+		}
+		return null;
+	}
+
+	public function isRoomOrResource(Property $attendee): bool {
+		$cuType = $attendee->offsetGet('CUTYPE');
+		if(!$cuType instanceof Parameter) {
+			return false;
+		}
+		$type = $cuType->getValue() ?? 'INDIVIDUAL';
+		if (\in_array(strtoupper($type), ['RESOURCE', 'ROOM', 'UNKNOWN'], true)) {
+			// Don't send emails to things
+			return true;
+		}
+		return false;
+	}
+}

wedding-pics/apps/dav/lib/CalDAV/Schedule/Plugin.php

@@ -0,0 +1,699 @@
+<?php
+/**
+ * @copyright Copyright (c) 2016, Roeland Jago Douma <roeland@famdouma.nl>
+ * @copyright Copyright (c) 2016, Joas Schilling <coding@schilljs.com>
+ *
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Daniel Kesselberg <mail@danielkesselberg.de>
+ * @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\Schedule;
+
+use DateTimeZone;
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCA\DAV\CalDAV\Calendar;
+use OCA\DAV\CalDAV\CalendarHome;
+use OCP\IConfig;
+use Psr\Log\LoggerInterface;
+use Sabre\CalDAV\ICalendar;
+use Sabre\CalDAV\ICalendarObject;
+use Sabre\CalDAV\Schedule\ISchedulingObject;
+use Sabre\DAV\INode;
+use Sabre\DAV\IProperties;
+use Sabre\DAV\PropFind;
+use Sabre\DAV\Server;
+use Sabre\DAV\Xml\Property\LocalHref;
+use Sabre\DAVACL\IACL;
+use Sabre\DAVACL\IPrincipal;
+use Sabre\HTTP\RequestInterface;
+use Sabre\HTTP\ResponseInterface;
+use Sabre\VObject\Component;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Component\VEvent;
+use Sabre\VObject\DateTimeParser;
+use Sabre\VObject\FreeBusyGenerator;
+use Sabre\VObject\ITip;
+use Sabre\VObject\ITip\SameOrganizerForAllComponentsException;
+use Sabre\VObject\Parameter;
+use Sabre\VObject\Property;
+use Sabre\VObject\Reader;
+use function \Sabre\Uri\split;
+
+class Plugin extends \Sabre\CalDAV\Schedule\Plugin {
+
+	/**
+	 * @var IConfig
+	 */
+	private $config;
+
+	/** @var ITip\Message[] */
+	private $schedulingResponses = [];
+
+	/** @var string|null */
+	private $pathOfCalendarObjectChange = null;
+
+	public const CALENDAR_USER_TYPE = '{' . self::NS_CALDAV . '}calendar-user-type';
+	public const SCHEDULE_DEFAULT_CALENDAR_URL = '{' . Plugin::NS_CALDAV . '}schedule-default-calendar-URL';
+	private LoggerInterface $logger;
+
+	/**
+	 * @param IConfig $config
+	 */
+	public function __construct(IConfig $config, LoggerInterface $logger) {
+		$this->config = $config;
+		$this->logger = $logger;
+	}
+
+	/**
+	 * Initializes the plugin
+	 *
+	 * @param Server $server
+	 * @return void
+	 */
+	public function initialize(Server $server) {
+		parent::initialize($server);
+		$server->on('propFind', [$this, 'propFindDefaultCalendarUrl'], 90);
+		$server->on('afterWriteContent', [$this, 'dispatchSchedulingResponses']);
+		$server->on('afterCreateFile', [$this, 'dispatchSchedulingResponses']);
+	}
+
+	/**
+	 * Allow manual setting of the object change URL
+	 * to support public write
+	 *
+	 * @param string $path
+	 */
+	public function setPathOfCalendarObjectChange(string $path): void {
+		$this->pathOfCalendarObjectChange = $path;
+	}
+
+	/**
+	 * This method handler is invoked during fetching of properties.
+	 *
+	 * We use this event to add calendar-auto-schedule-specific properties.
+	 *
+	 * @param PropFind $propFind
+	 * @param INode $node
+	 * @return void
+	 */
+	public function propFind(PropFind $propFind, INode $node) {
+		if ($node instanceof IPrincipal) {
+			// overwrite Sabre/Dav's implementation
+			$propFind->handle(self::CALENDAR_USER_TYPE, function () use ($node) {
+				if ($node instanceof IProperties) {
+					$props = $node->getProperties([self::CALENDAR_USER_TYPE]);
+
+					if (isset($props[self::CALENDAR_USER_TYPE])) {
+						return $props[self::CALENDAR_USER_TYPE];
+					}
+				}
+
+				return 'INDIVIDUAL';
+			});
+		}
+
+		parent::propFind($propFind, $node);
+	}
+
+	/**
+	 * Returns a list of addresses that are associated with a principal.
+	 *
+	 * @param string $principal
+	 * @return array
+	 */
+	protected function getAddressesForPrincipal($principal) {
+		$result = parent::getAddressesForPrincipal($principal);
+
+		if ($result === null) {
+			$result = [];
+		}
+
+		return $result;
+	}
+
+	/**
+	 * @param RequestInterface $request
+	 * @param ResponseInterface $response
+	 * @param VCalendar $vCal
+	 * @param mixed $calendarPath
+	 * @param mixed $modified
+	 * @param mixed $isNew
+	 */
+	public function calendarObjectChange(RequestInterface $request, ResponseInterface $response, VCalendar $vCal, $calendarPath, &$modified, $isNew) {
+		// Save the first path we get as a calendar-object-change request
+		if (!$this->pathOfCalendarObjectChange) {
+			$this->pathOfCalendarObjectChange = $request->getPath();
+		}
+
+		try {
+			parent::calendarObjectChange($request, $response, $vCal, $calendarPath, $modified, $isNew);
+		} catch (SameOrganizerForAllComponentsException $e) {
+			$this->handleSameOrganizerException($e, $vCal, $calendarPath);
+		}
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function beforeUnbind($path): void {
+		try {
+			parent::beforeUnbind($path);
+		} catch (SameOrganizerForAllComponentsException $e) {
+			$node = $this->server->tree->getNodeForPath($path);
+			if (!$node instanceof ICalendarObject || $node instanceof ISchedulingObject) {
+				throw $e;
+			}
+
+			/** @var VCalendar $vCal */
+			$vCal = Reader::read($node->get());
+			$this->handleSameOrganizerException($e, $vCal, $path);
+		}
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function scheduleLocalDelivery(ITip\Message $iTipMessage):void {
+		/** @var VEvent|null $vevent */
+		$vevent = $iTipMessage->message->VEVENT ?? null;
+
+		// Strip VALARMs from incoming VEVENT
+		if ($vevent && isset($vevent->VALARM)) {
+			$vevent->remove('VALARM');
+		}
+
+		parent::scheduleLocalDelivery($iTipMessage);
+		// We only care when the message was successfully delivered locally
+		// Log all possible codes returned from the parent method that mean something went wrong
+		// 3.7, 3.8, 5.0, 5.2
+		if ($iTipMessage->scheduleStatus !== '1.2;Message delivered locally') {
+			$this->logger->debug('Message not delivered locally with status: ' . $iTipMessage->scheduleStatus);
+			return;
+		}
+		// We only care about request. reply and cancel are properly handled
+		// by parent::scheduleLocalDelivery already
+		if (strcasecmp($iTipMessage->method, 'REQUEST') !== 0) {
+			return;
+		}
+
+		// If parent::scheduleLocalDelivery set scheduleStatus to 1.2,
+		// it means that it was successfully delivered locally.
+		// Meaning that the ACL plugin is loaded and that a principal
+		// exists for the given recipient id, no need to double check
+		/** @var \Sabre\DAVACL\Plugin $aclPlugin */
+		$aclPlugin = $this->server->getPlugin('acl');
+		$principalUri = $aclPlugin->getPrincipalByUri($iTipMessage->recipient);
+		$calendarUserType = $this->getCalendarUserTypeForPrincipal($principalUri);
+		if (strcasecmp($calendarUserType, 'ROOM') !== 0 && strcasecmp($calendarUserType, 'RESOURCE') !== 0) {
+			$this->logger->debug('Calendar user type is room or resource, not processing further');
+			return;
+		}
+
+		$attendee = $this->getCurrentAttendee($iTipMessage);
+		if (!$attendee) {
+			$this->logger->debug('No attendee set for scheduling message');
+			return;
+		}
+
+		// We only respond when a response was actually requested
+		$rsvp = $this->getAttendeeRSVP($attendee);
+		if (!$rsvp) {
+			$this->logger->debug('No RSVP requested for attendee ' . $attendee->getValue());
+			return;
+		}
+
+		if (!$vevent) {
+			$this->logger->debug('No VEVENT set to process on scheduling message');
+			return;
+		}
+
+		// We don't support autoresponses for recurrencing events for now
+		if (isset($vevent->RRULE) || isset($vevent->RDATE)) {
+			$this->logger->debug('VEVENT is a recurring event, autoresponding not supported');
+			return;
+		}
+
+		$dtstart = $vevent->DTSTART;
+		$dtend = $this->getDTEndFromVEvent($vevent);
+		$uid = $vevent->UID->getValue();
+		$sequence = isset($vevent->SEQUENCE) ? $vevent->SEQUENCE->getValue() : 0;
+		$recurrenceId = isset($vevent->{'RECURRENCE-ID'}) ? $vevent->{'RECURRENCE-ID'}->serialize() : '';
+
+		$message = <<<EOF
+BEGIN:VCALENDAR
+PRODID:-//Nextcloud/Nextcloud CalDAV Server//EN
+METHOD:REPLY
+VERSION:2.0
+BEGIN:VEVENT
+ATTENDEE;PARTSTAT=%s:%s
+ORGANIZER:%s
+UID:%s
+SEQUENCE:%s
+REQUEST-STATUS:2.0;Success
+%sEND:VEVENT
+END:VCALENDAR
+EOF;
+
+		if ($this->isAvailableAtTime($attendee->getValue(), $dtstart->getDateTime(), $dtend->getDateTime(), $uid)) {
+			$partStat = 'ACCEPTED';
+		} else {
+			$partStat = 'DECLINED';
+		}
+
+		$vObject = Reader::read(vsprintf($message, [
+			$partStat,
+			$iTipMessage->recipient,
+			$iTipMessage->sender,
+			$uid,
+			$sequence,
+			$recurrenceId
+		]));
+
+		$responseITipMessage = new ITip\Message();
+		$responseITipMessage->uid = $uid;
+		$responseITipMessage->component = 'VEVENT';
+		$responseITipMessage->method = 'REPLY';
+		$responseITipMessage->sequence = $sequence;
+		$responseITipMessage->sender = $iTipMessage->recipient;
+		$responseITipMessage->recipient = $iTipMessage->sender;
+		$responseITipMessage->message = $vObject;
+
+		// We can't dispatch them now already, because the organizers calendar-object
+		// was not yet created. Hence Sabre/DAV won't find a calendar-object, when we
+		// send our reply.
+		$this->schedulingResponses[] = $responseITipMessage;
+	}
+
+	/**
+	 * @param string $uri
+	 */
+	public function dispatchSchedulingResponses(string $uri):void {
+		if ($uri !== $this->pathOfCalendarObjectChange) {
+			return;
+		}
+
+		foreach ($this->schedulingResponses as $schedulingResponse) {
+			$this->scheduleLocalDelivery($schedulingResponse);
+		}
+	}
+
+	/**
+	 * Always use the personal calendar as target for scheduled events
+	 *
+	 * @param PropFind $propFind
+	 * @param INode $node
+	 * @return void
+	 */
+	public function propFindDefaultCalendarUrl(PropFind $propFind, INode $node) {
+		if ($node instanceof IPrincipal) {
+			$propFind->handle(self::SCHEDULE_DEFAULT_CALENDAR_URL, function () use ($node) {
+				/** @var \OCA\DAV\CalDAV\Plugin $caldavPlugin */
+				$caldavPlugin = $this->server->getPlugin('caldav');
+				$principalUrl = $node->getPrincipalUrl();
+
+				$calendarHomePath = $caldavPlugin->getCalendarHomeForPrincipal($principalUrl);
+				if (!$calendarHomePath) {
+					return null;
+				}
+
+				$isResourceOrRoom = str_starts_with($principalUrl, 'principals/calendar-resources') ||
+					str_starts_with($principalUrl, 'principals/calendar-rooms');
+
+				if (str_starts_with($principalUrl, 'principals/users')) {
+					[, $userId] = split($principalUrl);
+					$uri = $this->config->getUserValue($userId, 'dav', 'defaultCalendar', CalDavBackend::PERSONAL_CALENDAR_URI);
+					$displayName = CalDavBackend::PERSONAL_CALENDAR_NAME;
+				} elseif ($isResourceOrRoom) {
+					$uri = CalDavBackend::RESOURCE_BOOKING_CALENDAR_URI;
+					$displayName = CalDavBackend::RESOURCE_BOOKING_CALENDAR_NAME;
+				} else {
+					// How did we end up here?
+					// TODO - throw exception or just ignore?
+					return null;
+				}
+
+				/** @var CalendarHome $calendarHome */
+				$calendarHome = $this->server->tree->getNodeForPath($calendarHomePath);
+				$currentCalendarDeleted = false;
+				if (!$calendarHome->childExists($uri) || $currentCalendarDeleted = $this->isCalendarDeleted($calendarHome, $uri)) {
+					// If the default calendar doesn't exist
+					if ($isResourceOrRoom) {
+						// Resources or rooms can't be in the trashbin, so we're fine
+						$this->createCalendar($calendarHome, $principalUrl, $uri, $displayName);
+					} else {
+						// And we're not handling scheduling on resource/room booking
+						$userCalendars = [];
+						/**
+						 * If the default calendar of the user isn't set and the
+						 * fallback doesn't match any of the user's calendar
+						 * try to find the first "personal" calendar we can write to
+						 * instead of creating a new one.
+						 * A appropriate personal calendar to receive invites:
+						 * - isn't a calendar subscription
+						 * - user can write to it (no virtual/3rd-party calendars)
+						 * - calendar isn't a share
+						 */
+						foreach ($calendarHome->getChildren() as $node) {
+							if ($node instanceof Calendar && !$node->isSubscription() && $node->canWrite() && !$node->isShared() && !$node->isDeleted()) {
+								$userCalendars[] = $node;
+							}
+						}
+
+						if (count($userCalendars) > 0) {
+							// Calendar backend returns calendar by calendarorder property
+							$uri = $userCalendars[0]->getName();
+						} else {
+							// Otherwise if we have really nothing, create a new calendar
+							if ($currentCalendarDeleted) {
+								// If the calendar exists but is deleted, we need to purge it first
+								// This may cause some issues in a non synchronous database setup
+								$calendar = $this->getCalendar($calendarHome, $uri);
+								if ($calendar instanceof Calendar) {
+									$calendar->disableTrashbin();
+									$calendar->delete();
+								}
+							}
+							$this->createCalendar($calendarHome, $principalUrl, $uri, $displayName);
+						}
+					}
+				}
+
+				$result = $this->server->getPropertiesForPath($calendarHomePath . '/' . $uri, [], 1);
+				if (empty($result)) {
+					return null;
+				}
+
+				return new LocalHref($result[0]['href']);
+			});
+		}
+	}
+
+	/**
+	 * Returns a list of addresses that are associated with a principal.
+	 *
+	 * @param string $principal
+	 * @return string|null
+	 */
+	protected function getCalendarUserTypeForPrincipal($principal):?string {
+		$calendarUserType = '{' . self::NS_CALDAV . '}calendar-user-type';
+		$properties = $this->server->getProperties(
+			$principal,
+			[$calendarUserType]
+		);
+
+		// If we can't find this information, we'll stop processing
+		if (!isset($properties[$calendarUserType])) {
+			return null;
+		}
+
+		return $properties[$calendarUserType];
+	}
+
+	/**
+	 * @param ITip\Message $iTipMessage
+	 * @return null|Property
+	 */
+	private function getCurrentAttendee(ITip\Message $iTipMessage):?Property {
+		/** @var VEvent $vevent */
+		$vevent = $iTipMessage->message->VEVENT;
+		$attendees = $vevent->select('ATTENDEE');
+		foreach ($attendees as $attendee) {
+			/** @var Property $attendee */
+			if (strcasecmp($attendee->getValue(), $iTipMessage->recipient) === 0) {
+				return $attendee;
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * @param Property|null $attendee
+	 * @return bool
+	 */
+	private function getAttendeeRSVP(Property $attendee = null):bool {
+		if ($attendee !== null) {
+			$rsvp = $attendee->offsetGet('RSVP');
+			if (($rsvp instanceof Parameter) && (strcasecmp($rsvp->getValue(), 'TRUE') === 0)) {
+				return true;
+			}
+		}
+		// RFC 5545 3.2.17: default RSVP is false
+		return false;
+	}
+
+	/**
+	 * @param VEvent $vevent
+	 * @return Property\ICalendar\DateTime
+	 */
+	private function getDTEndFromVEvent(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;
+	}
+
+	/**
+	 * @param string $email
+	 * @param \DateTimeInterface $start
+	 * @param \DateTimeInterface $end
+	 * @param string $ignoreUID
+	 * @return bool
+	 */
+	private function isAvailableAtTime(string $email, \DateTimeInterface $start, \DateTimeInterface $end, string $ignoreUID):bool {
+		// This method is heavily inspired by Sabre\CalDAV\Schedule\Plugin::scheduleLocalDelivery
+		// and Sabre\CalDAV\Schedule\Plugin::getFreeBusyForEmail
+
+		$aclPlugin = $this->server->getPlugin('acl');
+		$this->server->removeListener('propFind', [$aclPlugin, 'propFind']);
+
+		$result = $aclPlugin->principalSearch(
+			['{http://sabredav.org/ns}email-address' => $this->stripOffMailTo($email)],
+			[
+				'{DAV:}principal-URL',
+				'{' . self::NS_CALDAV . '}calendar-home-set',
+				'{' . self::NS_CALDAV . '}schedule-inbox-URL',
+				'{http://sabredav.org/ns}email-address',
+
+			]
+		);
+		$this->server->on('propFind', [$aclPlugin, 'propFind'], 20);
+
+
+		// Grabbing the calendar list
+		$objects = [];
+		$calendarTimeZone = new DateTimeZone('UTC');
+
+		$homePath = $result[0][200]['{' . self::NS_CALDAV . '}calendar-home-set']->getHref();
+		foreach ($this->server->tree->getNodeForPath($homePath)->getChildren() as $node) {
+			if (!$node instanceof ICalendar) {
+				continue;
+			}
+
+			// Getting the list of object uris within the time-range
+			$urls = $node->calendarQuery([
+				'name' => 'VCALENDAR',
+				'comp-filters' => [
+					[
+						'name' => 'VEVENT',
+						'is-not-defined' => false,
+						'time-range' => [
+							'start' => $start,
+							'end' => $end,
+						],
+						'comp-filters' => [],
+						'prop-filters' => [],
+					],
+					[
+						'name' => 'VEVENT',
+						'is-not-defined' => false,
+						'time-range' => null,
+						'comp-filters' => [],
+						'prop-filters' => [
+							[
+								'name' => 'UID',
+								'is-not-defined' => false,
+								'time-range' => null,
+								'text-match' => [
+									'value' => $ignoreUID,
+									'negate-condition' => true,
+									'collation' => 'i;octet',
+								],
+								'param-filters' => [],
+							],
+						]
+					],
+				],
+				'prop-filters' => [],
+				'is-not-defined' => false,
+				'time-range' => null,
+			]);
+
+			foreach ($urls as $url) {
+				$objects[] = $node->getChild($url)->get();
+			}
+		}
+
+		$inboxProps = $this->server->getProperties(
+			$result[0][200]['{' . self::NS_CALDAV . '}schedule-inbox-URL']->getHref(),
+			['{' . self::NS_CALDAV . '}calendar-availability']
+		);
+
+		$vcalendar = new VCalendar();
+		$vcalendar->METHOD = 'REPLY';
+
+		$generator = new FreeBusyGenerator();
+		$generator->setObjects($objects);
+		$generator->setTimeRange($start, $end);
+		$generator->setBaseObject($vcalendar);
+		$generator->setTimeZone($calendarTimeZone);
+
+		if (isset($inboxProps['{' . self::NS_CALDAV . '}calendar-availability'])) {
+			$generator->setVAvailability(
+				Reader::read(
+					$inboxProps['{' . self::NS_CALDAV . '}calendar-availability']
+				)
+			);
+		}
+
+		$result = $generator->getResult();
+		if (!isset($result->VFREEBUSY)) {
+			return false;
+		}
+
+		/** @var Component $freeBusyComponent */
+		$freeBusyComponent = $result->VFREEBUSY;
+		$freeBusyProperties = $freeBusyComponent->select('FREEBUSY');
+		// If there is no Free-busy property at all, the time-range is empty and available
+		if (count($freeBusyProperties) === 0) {
+			return true;
+		}
+
+		// If more than one Free-Busy property was returned, it means that an event
+		// starts or ends inside this time-range, so it's not available and we return false
+		if (count($freeBusyProperties) > 1) {
+			return false;
+		}
+
+		/** @var Property $freeBusyProperty */
+		$freeBusyProperty = $freeBusyProperties[0];
+		if (!$freeBusyProperty->offsetExists('FBTYPE')) {
+			// If there is no FBTYPE, it means it's busy
+			return false;
+		}
+
+		$fbTypeParameter = $freeBusyProperty->offsetGet('FBTYPE');
+		if (!($fbTypeParameter instanceof Parameter)) {
+			return false;
+		}
+
+		return (strcasecmp($fbTypeParameter->getValue(), 'FREE') === 0);
+	}
+
+	/**
+	 * @param string $email
+	 * @return string
+	 */
+	private function stripOffMailTo(string $email): string {
+		if (stripos($email, 'mailto:') === 0) {
+			return substr($email, 7);
+		}
+
+		return $email;
+	}
+
+	private function getCalendar(CalendarHome $calendarHome, string $uri): INode {
+		return $calendarHome->getChild($uri);
+	}
+
+	private function isCalendarDeleted(CalendarHome $calendarHome, string $uri): bool {
+		$calendar = $this->getCalendar($calendarHome, $uri);
+		return $calendar instanceof Calendar && $calendar->isDeleted();
+	}
+
+	private function createCalendar(CalendarHome $calendarHome, string $principalUri, string $uri, string $displayName): void {
+		$calendarHome->getCalDAVBackend()->createCalendar($principalUri, $uri, [
+			'{DAV:}displayname' => $displayName,
+		]);
+	}
+
+	/**
+	 * Try to handle the given exception gracefully or throw it if necessary.
+	 *
+	 * @throws SameOrganizerForAllComponentsException If the exception should not be ignored
+	 */
+	private function handleSameOrganizerException(
+		SameOrganizerForAllComponentsException $e,
+		VCalendar $vCal,
+		string $calendarPath,
+	): void {
+		// This is very hacky! However, we want to allow saving events with multiple
+		// organizers. Those events are not RFC compliant, but sometimes imported from major
+		// external calendar services (e.g. Google). If the current user is not an organizer of
+		// the event we ignore the exception as no scheduling messages will be sent anyway.
+
+		// It would be cleaner to patch Sabre to validate organizers *after* checking if
+		// scheduling messages are necessary. Currently, organizers are validated first and
+		// afterwards the broker checks if messages should be scheduled. So the code will throw
+		// even if the organizers are not relevant. This is to ensure compliance with RFCs but
+		// a bit too strict for real world usage.
+
+		if (!isset($vCal->VEVENT)) {
+			throw $e;
+		}
+
+		$calendarNode = $this->server->tree->getNodeForPath($calendarPath);
+		if (!($calendarNode instanceof IACL)) {
+			// Should always be an instance of IACL but just to be sure
+			throw $e;
+		}
+
+		$addresses = $this->getAddressesForPrincipal($calendarNode->getOwner());
+		foreach ($vCal->VEVENT as $vevent) {
+			if (in_array($vevent->ORGANIZER->getNormalizedValue(), $addresses, true)) {
+				// User is an organizer => throw the exception
+				throw $e;
+			}
+		}
+	}
+}