nextcloud / server

apps/dav/lib/CalDAV/Schedule/IMipService.php

Indentation +1283 added lines, -1283 removed lines

@@ -29,1287 +29,1287 @@
 
 class IMipService {
 
-	private IL10N $l10n;
-
-	/** @var string[] */
-	private const STRING_DIFF = [
-		'meeting_title' => 'SUMMARY',
-		'meeting_description' => 'DESCRIPTION',
-		'meeting_url' => 'URL',
-		'meeting_location' => 'LOCATION'
-	];
-
-	public function __construct(
-		private URLGenerator $urlGenerator,
-		private IConfig $config,
-		private IDBConnection $db,
-		private ISecureRandom $random,
-		private L10NFactory $l10nFactory,
-		private ITimeFactory $timeFactory,
-		private readonly IUserManager $userManager,
-	) {
-		$language = $this->l10nFactory->findGenericLanguage();
-		$locale = $this->l10nFactory->findLocale($language);
-		$this->l10n = $this->l10nFactory->get('dav', $language, $locale);
-	}
-
-	/**
-	 * @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;
-		}
-		$value = $vevent->$property->getValue();
-		$newstring = $value === null ? null : htmlspecialchars($value);
-		if (isset($oldVEvent->$property) && $oldVEvent->$property->getValue() !== $newstring) {
-			$oldstring = $oldVEvent->$property->getValue();
-			return sprintf($strikethrough, htmlspecialchars($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 */
-		$newString = htmlspecialchars($vevent->$property->getValue());
-		$oldString = isset($oldVEvent->$property) ? htmlspecialchars($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 {
-
-		// construct event reader
-		$eventReaderCurrent = new EventReader($vEvent);
-		$eventReaderPrevious = !empty($oldVEvent) ? new EventReader($oldVEvent) : null;
-		$defaultVal = '';
-		$data = [];
-		$data['meeting_when'] = $this->generateWhenString($eventReaderCurrent);
-
-		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 = $this->generateWhenString($eventReaderPrevious);
-			$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'] ? sprintf("<span style='text-decoration: line-through'>%s</span><br />%s", $oldMeetingWhen, $data['meeting_when']) : $data['meeting_when'];
-		}
-		// generate occurring next string
-		if ($eventReaderCurrent->recurs()) {
-			$data['meeting_occurring'] = $this->generateOccurringString($eventReaderCurrent);
-		}
-		return $data;
-	}
-
-	/**
-	 * @param VEvent $vEvent
-	 * @return array
-	 */
-	public function buildReplyBodyData(VEvent $vEvent): array {
-		// construct event reader
-		$eventReader = new EventReader($vEvent);
-		$defaultVal = '';
-		$data = [];
-		$data['meeting_when'] = $this->generateWhenString($eventReader);
-
-		foreach (self::STRING_DIFF as $key => $property) {
-			$data[$key] = self::readPropertyWithDefault($vEvent, $property, $defaultVal);
-		}
-
-		if (($locationHtml = $this->linkify($data['meeting_location'])) !== null) {
-			$data['meeting_location_html'] = $locationHtml;
-		}
-
-		$data['meeting_url_html'] = $data['meeting_url'] ? sprintf('<a href="%1$s">%1$s</a>', $data['meeting_url']) : '';
-
-		// generate occurring next string
-		if ($eventReader->recurs()) {
-			$data['meeting_occurring'] = $this->generateOccurringString($eventReader);
-		}
-
-		return $data;
-	}
-
-	/**
-	 * generates a when string based on if a event has an recurrence or not
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateWhenString(EventReader $er): string {
-		return match ($er->recurs()) {
-			true => $this->generateWhenStringRecurring($er),
-			false => $this->generateWhenStringSingular($er)
-		};
-	}
-
-	/**
-	 * generates a when string for a non recurring event
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateWhenStringSingular(EventReader $er): string {
-		// initialize
-		$startTime = null;
-		$endTime = null;
-		// calculate time difference from now to start of event
-		$occurring = $this->minimizeInterval($this->timeFactory->getDateTime()->diff($er->recurrenceDate()));
-		// extract start date
-		$startDate = $this->l10n->l('date', $er->startDateTime(), ['width' => 'full']);
-		// time of the day
-		if (!$er->entireDay()) {
-			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
-		}
-		// generate localized when string
-		// TRANSLATORS
-		// Indicates when a calendar event will happen, shown on invitation emails
-		// Output produced in order:
-		// In 1 minute/hour/day/week/month/year on July 1, 2024 for the entire day
-		// In 1 minute/hour/day/week/month/year on July 1, 2024 between 8:00 AM - 9:00 AM (America/Toronto)
-		// In 2 minutes/hours/days/weeks/months/years on July 1, 2024 for the entire day
-		// In 2 minutes/hours/days/weeks/months/years on July 1, 2024 between 8:00 AM - 9:00 AM (America/Toronto)
-		return match ([$occurring['scale'], $endTime !== null]) {
-			['past', false] => $this->l10n->t(
-				'In the past on %1$s for the entire day',
-				[$startDate]
-			),
-			['minute', false] => $this->l10n->n(
-				'In %n minute on %1$s for the entire day',
-				'In %n minutes on %1$s for the entire day',
-				$occurring['interval'],
-				[$startDate]
-			),
-			['hour', false] => $this->l10n->n(
-				'In %n hour on %1$s for the entire day',
-				'In %n hours on %1$s for the entire day',
-				$occurring['interval'],
-				[$startDate]
-			),
-			['day', false] => $this->l10n->n(
-				'In %n day on %1$s for the entire day',
-				'In %n days on %1$s for the entire day',
-				$occurring['interval'],
-				[$startDate]
-			),
-			['week', false] => $this->l10n->n(
-				'In %n week on %1$s for the entire day',
-				'In %n weeks on %1$s for the entire day',
-				$occurring['interval'],
-				[$startDate]
-			),
-			['month', false] => $this->l10n->n(
-				'In %n month on %1$s for the entire day',
-				'In %n months on %1$s for the entire day',
-				$occurring['interval'],
-				[$startDate]
-			),
-			['year', false] => $this->l10n->n(
-				'In %n year on %1$s for the entire day',
-				'In %n years on %1$s for the entire day',
-				$occurring['interval'],
-				[$startDate]
-			),
-			['past', true] => $this->l10n->t(
-				'In the past on %1$s between %2$s - %3$s',
-				[$startDate, $startTime, $endTime]
-			),
-			['minute', true] => $this->l10n->n(
-				'In %n minute on %1$s between %2$s - %3$s',
-				'In %n minutes on %1$s between %2$s - %3$s',
-				$occurring['interval'],
-				[$startDate, $startTime, $endTime]
-			),
-			['hour', true] => $this->l10n->n(
-				'In %n hour on %1$s between %2$s - %3$s',
-				'In %n hours on %1$s between %2$s - %3$s',
-				$occurring['interval'],
-				[$startDate, $startTime, $endTime]
-			),
-			['day', true] => $this->l10n->n(
-				'In %n day on %1$s between %2$s - %3$s',
-				'In %n days on %1$s between %2$s - %3$s',
-				$occurring['interval'],
-				[$startDate, $startTime, $endTime]
-			),
-			['week', true] => $this->l10n->n(
-				'In %n week on %1$s between %2$s - %3$s',
-				'In %n weeks on %1$s between %2$s - %3$s',
-				$occurring['interval'],
-				[$startDate, $startTime, $endTime]
-			),
-			['month', true] => $this->l10n->n(
-				'In %n month on %1$s between %2$s - %3$s',
-				'In %n months on %1$s between %2$s - %3$s',
-				$occurring['interval'],
-				[$startDate, $startTime, $endTime]
-			),
-			['year', true] => $this->l10n->n(
-				'In %n year on %1$s between %2$s - %3$s',
-				'In %n years on %1$s between %2$s - %3$s',
-				$occurring['interval'],
-				[$startDate, $startTime, $endTime]
-			),
-			default => $this->l10n->t('Could not generate when statement')
-		};
-	}
-
-	/**
-	 * generates a when string based on recurrence precision/frequency
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateWhenStringRecurring(EventReader $er): string {
-		return match ($er->recurringPrecision()) {
-			'daily' => $this->generateWhenStringRecurringDaily($er),
-			'weekly' => $this->generateWhenStringRecurringWeekly($er),
-			'monthly' => $this->generateWhenStringRecurringMonthly($er),
-			'yearly' => $this->generateWhenStringRecurringYearly($er),
-			'fixed' => $this->generateWhenStringRecurringFixed($er),
-		};
-	}
-
-	/**
-	 * generates a when string for a daily precision/frequency
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateWhenStringRecurringDaily(EventReader $er): string {
-
-		// initialize
-		$interval = (int)$er->recurringInterval();
-		$startTime = null;
-		$conclusion = null;
-		// time of the day
-		if (!$er->entireDay()) {
-			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
-		}
-		// conclusion
-		if ($er->recurringConcludes()) {
-			$conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
-		}
-		// generate localized when string
-		// TRANSLATORS
-		// Indicates when a calendar event will happen, shown on invitation emails
-		// Output produced in order:
-		// Every Day for the entire day
-		// Every Day for the entire day until July 13, 2024
-		// Every Day between 8:00 AM - 9:00 AM (America/Toronto)
-		// Every Day between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
-		// Every 3 Days for the entire day
-		// Every 3 Days for the entire day until July 13, 2024
-		// Every 3 Days between 8:00 AM - 9:00 AM (America/Toronto)
-		// Every 3 Days between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
-		return match ([($interval > 1), $startTime !== null, $conclusion !== null]) {
-			[false, false, false] => $this->l10n->t('Every Day for the entire day'),
-			[false, false, true] => $this->l10n->t('Every Day for the entire day until %1$s', [$conclusion]),
-			[false, true, false] => $this->l10n->t('Every Day between %1$s - %2$s', [$startTime, $endTime]),
-			[false, true, true] => $this->l10n->t('Every Day between %1$s - %2$s until %3$s', [$startTime, $endTime, $conclusion]),
-			[true, false, false] => $this->l10n->t('Every %1$d Days for the entire day', [$interval]),
-			[true, false, true] => $this->l10n->t('Every %1$d Days for the entire day until %2$s', [$interval, $conclusion]),
-			[true, true, false] => $this->l10n->t('Every %1$d Days between %2$s - %3$s', [$interval, $startTime, $endTime]),
-			[true, true, true] => $this->l10n->t('Every %1$d Days between %2$s - %3$s until %4$s', [$interval, $startTime, $endTime, $conclusion]),
-			default => $this->l10n->t('Could not generate event recurrence statement')
-		};
-
-	}
-
-	/**
-	 * generates a when string for a weekly precision/frequency
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateWhenStringRecurringWeekly(EventReader $er): string {
-
-		// initialize
-		$interval = (int)$er->recurringInterval();
-		$startTime = null;
-		$conclusion = null;
-		// days of the week
-		$days = implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
-		// time of the day
-		if (!$er->entireDay()) {
-			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
-		}
-		// conclusion
-		if ($er->recurringConcludes()) {
-			$conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
-		}
-		// generate localized when string
-		// TRANSLATORS
-		// Indicates when a calendar event will happen, shown on invitation emails
-		// Output produced in order:
-		// Every Week on Monday, Wednesday, Friday for the entire day
-		// Every Week on Monday, Wednesday, Friday for the entire day until July 13, 2024
-		// Every Week on Monday, Wednesday, Friday between 8:00 AM - 9:00 AM (America/Toronto)
-		// Every Week on Monday, Wednesday, Friday between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
-		// Every 2 Weeks on Monday, Wednesday, Friday for the entire day
-		// Every 2 Weeks on Monday, Wednesday, Friday for the entire day until July 13, 2024
-		// Every 2 Weeks on Monday, Wednesday, Friday between 8:00 AM - 9:00 AM (America/Toronto)
-		// Every 2 Weeks on Monday, Wednesday, Friday between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
-		return match ([($interval > 1), $startTime !== null, $conclusion !== null]) {
-			[false, false, false] => $this->l10n->t('Every Week on %1$s for the entire day', [$days]),
-			[false, false, true] => $this->l10n->t('Every Week on %1$s for the entire day until %2$s', [$days, $conclusion]),
-			[false, true, false] => $this->l10n->t('Every Week on %1$s between %2$s - %3$s', [$days, $startTime, $endTime]),
-			[false, true, true] => $this->l10n->t('Every Week on %1$s between %2$s - %3$s until %4$s', [$days, $startTime, $endTime, $conclusion]),
-			[true, false, false] => $this->l10n->t('Every %1$d Weeks on %2$s for the entire day', [$interval, $days]),
-			[true, false, true] => $this->l10n->t('Every %1$d Weeks on %2$s for the entire day until %3$s', [$interval, $days, $conclusion]),
-			[true, true, false] => $this->l10n->t('Every %1$d Weeks on %2$s between %3$s - %4$s', [$interval, $days, $startTime, $endTime]),
-			[true, true, true] => $this->l10n->t('Every %1$d Weeks on %2$s between %3$s - %4$s until %5$s', [$interval, $days, $startTime, $endTime, $conclusion]),
-			default => $this->l10n->t('Could not generate event recurrence statement')
-		};
-
-	}
-
-	/**
-	 * generates a when string for a monthly precision/frequency
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateWhenStringRecurringMonthly(EventReader $er): string {
-
-		// initialize
-		$interval = (int)$er->recurringInterval();
-		$startTime = null;
-		$conclusion = null;
-		// days of month
-		if ($er->recurringPattern() === 'R') {
-			$days = implode(', ', array_map(function ($value) { return $this->localizeRelativePositionName($value); }, $er->recurringRelativePositionNamed())) . ' '
-					. implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
-		} else {
-			$days = implode(', ', $er->recurringDaysOfMonth());
-		}
-		// time of the day
-		if (!$er->entireDay()) {
-			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
-		}
-		// conclusion
-		if ($er->recurringConcludes()) {
-			$conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
-		}
-		// generate localized when string
-		// TRANSLATORS
-		// Indicates when a calendar event will happen, shown on invitation emails
-		// Output produced in order, output varies depending on if the event is absolute or releative:
-		// Absolute: Every Month on the 1, 8 for the entire day
-		// Relative: Every Month on the First Sunday, Saturday for the entire day
-		// Absolute: Every Month on the 1, 8 for the entire day until December 31, 2024
-		// Relative: Every Month on the First Sunday, Saturday for the entire day until December 31, 2024
-		// Absolute: Every Month on the 1, 8 between 8:00 AM - 9:00 AM (America/Toronto)
-		// Relative: Every Month on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto)
-		// Absolute: Every Month on the 1, 8 between 8:00 AM - 9:00 AM (America/Toronto) until December 31, 2024
-		// Relative: Every Month on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto) until December 31, 2024
-		// Absolute: Every 2 Months on the 1, 8 for the entire day
-		// Relative: Every 2 Months on the First Sunday, Saturday for the entire day
-		// Absolute: Every 2 Months on the 1, 8 for the entire day until December 31, 2024
-		// Relative: Every 2 Months on the First Sunday, Saturday for the entire day until December 31, 2024
-		// Absolute: Every 2 Months on the 1, 8 between 8:00 AM - 9:00 AM (America/Toronto)
-		// Relative: Every 2 Months on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto)
-		// Absolute: Every 2 Months on the 1, 8 between 8:00 AM - 9:00 AM (America/Toronto) until December 31, 2024
-		// Relative: Every 2 Months on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto) until December 31, 2024
-		return match ([($interval > 1), $startTime !== null, $conclusion !== null]) {
-			[false, false, false] => $this->l10n->t('Every Month on the %1$s for the entire day', [$days]),
-			[false, false, true] => $this->l10n->t('Every Month on the %1$s for the entire day until %2$s', [$days, $conclusion]),
-			[false, true, false] => $this->l10n->t('Every Month on the %1$s between %2$s - %3$s', [$days, $startTime, $endTime]),
-			[false, true, true] => $this->l10n->t('Every Month on the %1$s between %2$s - %3$s until %4$s', [$days, $startTime, $endTime, $conclusion]),
-			[true, false, false] => $this->l10n->t('Every %1$d Months on the %2$s for the entire day', [$interval, $days]),
-			[true, false, true] => $this->l10n->t('Every %1$d Months on the %2$s for the entire day until %3$s', [$interval, $days, $conclusion]),
-			[true, true, false] => $this->l10n->t('Every %1$d Months on the %2$s between %3$s - %4$s', [$interval, $days, $startTime, $endTime]),
-			[true, true, true] => $this->l10n->t('Every %1$d Months on the %2$s between %3$s - %4$s until %5$s', [$interval, $days, $startTime, $endTime, $conclusion]),
-			default => $this->l10n->t('Could not generate event recurrence statement')
-		};
-	}
-
-	/**
-	 * generates a when string for a yearly precision/frequency
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateWhenStringRecurringYearly(EventReader $er): string {
-
-		// initialize
-		$interval = (int)$er->recurringInterval();
-		$startTime = null;
-		$conclusion = null;
-		// months of year
-		$months = implode(', ', array_map(function ($value) { return $this->localizeMonthName($value); }, $er->recurringMonthsOfYearNamed()));
-		// days of month
-		if ($er->recurringPattern() === 'R') {
-			$days = implode(', ', array_map(function ($value) { return $this->localizeRelativePositionName($value); }, $er->recurringRelativePositionNamed())) . ' '
-					. implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
-		} else {
-			$days = $er->startDateTime()->format('jS');
-		}
-		// time of the day
-		if (!$er->entireDay()) {
-			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
-		}
-		// conclusion
-		if ($er->recurringConcludes()) {
-			$conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
-		}
-		// generate localized when string
-		// TRANSLATORS
-		// Indicates when a calendar event will happen, shown on invitation emails
-		// Output produced in order, output varies depending on if the event is absolute or releative:
-		// Absolute: Every Year in July on the 1st for the entire day
-		// Relative: Every Year in July on the First Sunday, Saturday for the entire day
-		// Absolute: Every Year in July on the 1st for the entire day until July 31, 2026
-		// Relative: Every Year in July on the First Sunday, Saturday for the entire day until July 31, 2026
-		// Absolute: Every Year in July on the 1st between 8:00 AM - 9:00 AM (America/Toronto)
-		// Relative: Every Year in July on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto)
-		// Absolute: Every Year in July on the 1st between 8:00 AM - 9:00 AM (America/Toronto) until July 31, 2026
-		// Relative: Every Year in July on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto) until July 31, 2026
-		// Absolute: Every 2 Years in July on the 1st for the entire day
-		// Relative: Every 2 Years in July on the First Sunday, Saturday for the entire day
-		// Absolute: Every 2 Years in July on the 1st for the entire day until July 31, 2026
-		// Relative: Every 2 Years in July on the First Sunday, Saturday for the entire day until July 31, 2026
-		// Absolute: Every 2 Years in July on the 1st between 8:00 AM - 9:00 AM (America/Toronto)
-		// Relative: Every 2 Years in July on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto)
-		// Absolute: Every 2 Years in July on the 1st between 8:00 AM - 9:00 AM (America/Toronto) until July 31, 2026
-		// Relative: Every 2 Years in July on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto) until July 31, 2026
-		return match ([($interval > 1), $startTime !== null, $conclusion !== null]) {
-			[false, false, false] => $this->l10n->t('Every Year in %1$s on the %2$s for the entire day', [$months, $days]),
-			[false, false, true] => $this->l10n->t('Every Year in %1$s on the %2$s for the entire day until %3$s', [$months, $days, $conclusion]),
-			[false, true, false] => $this->l10n->t('Every Year in %1$s on the %2$s between %3$s - %4$s', [$months, $days, $startTime, $endTime]),
-			[false, true, true] => $this->l10n->t('Every Year in %1$s on the %2$s between %3$s - %4$s until %5$s', [$months, $days, $startTime, $endTime, $conclusion]),
-			[true, false, false] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s for the entire day', [$interval, $months, $days]),
-			[true, false, true] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s for the entire day until %4$s', [$interval, $months,  $days, $conclusion]),
-			[true, true, false] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s between %4$s - %5$s', [$interval, $months, $days, $startTime, $endTime]),
-			[true, true, true] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s between %4$s - %5$s until %6$s', [$interval, $months, $days, $startTime, $endTime, $conclusion]),
-			default => $this->l10n->t('Could not generate event recurrence statement')
-		};
-	}
-
-	/**
-	 * generates a when string for a fixed precision/frequency
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateWhenStringRecurringFixed(EventReader $er): string {
-		// initialize
-		$startTime = null;
-		$conclusion = null;
-		// time of the day
-		if (!$er->entireDay()) {
-			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
-		}
-		// conclusion
-		$conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
-		// generate localized when string
-		// TRANSLATORS
-		// Indicates when a calendar event will happen, shown on invitation emails
-		// Output produced in order:
-		// On specific dates for the entire day until July 13, 2024
-		// On specific dates between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
-		return match ($startTime !== null) {
-			false => $this->l10n->t('On specific dates for the entire day until %1$s', [$conclusion]),
-			true => $this->l10n->t('On specific dates between %1$s - %2$s until %3$s', [$startTime, $endTime, $conclusion]),
-		};
-	}
-
-	/**
-	 * generates a occurring next string for a recurring event
-	 *
-	 * @since 30.0.0
-	 *
-	 * @param EventReader $er
-	 *
-	 * @return string
-	 */
-	public function generateOccurringString(EventReader $er): string {
-
-		// initialize
-		$occurrence = null;
-		$occurrence2 = null;
-		$occurrence3 = null;
-		// reset to initial occurrence
-		$er->recurrenceRewind();
-		// forward to current date
-		$er->recurrenceAdvanceTo($this->timeFactory->getDateTime());
-		// calculate time difference from now to start of next event occurrence and minimize it
-		$occurrenceIn = $this->minimizeInterval($this->timeFactory->getDateTime()->diff($er->recurrenceDate()));
-		// store next occurrence value
-		$occurrence = $this->l10n->l('date', $er->recurrenceDate(), ['width' => 'long']);
-		// forward one occurrence
-		$er->recurrenceAdvance();
-		// evaluate if occurrence is valid
-		if ($er->recurrenceDate() !== null) {
-			// store following occurrence value
-			$occurrence2 = $this->l10n->l('date', $er->recurrenceDate(), ['width' => 'long']);
-			// forward one occurrence
-			$er->recurrenceAdvance();
-			// evaluate if occurrence is valid
-			if ($er->recurrenceDate()) {
-				// store following occurrence value
-				$occurrence3 = $this->l10n->l('date', $er->recurrenceDate(), ['width' => 'long']);
-			}
-		}
-		// generate localized when string
-		// TRANSLATORS
-		// Indicates when a calendar event will happen, shown on invitation emails
-		// Output produced in order:
-		// In 1 minute/hour/day/week/month/year on July 1, 2024
-		// In 1 minute/hour/day/week/month/year on July 1, 2024 then on July 3, 2024
-		// In 1 minute/hour/day/week/month/year on July 1, 2024 then on July 3, 2024 and July 5, 2024
-		// In 2 minutes/hours/days/weeks/months/years on July 1, 2024
-		// In 2 minutes/hours/days/weeks/months/years on July 1, 2024 then on July 3, 2024
-		// In 2 minutes/hours/days/weeks/months/years on July 1, 2024 then on July 3, 2024 and July 5, 2024
-		return match ([$occurrenceIn['scale'], $occurrence2 !== null, $occurrence3 !== null]) {
-			['past', false, false] => $this->l10n->t(
-				'In the past on %1$s',
-				[$occurrence]
-			),
-			['minute', false, false] => $this->l10n->n(
-				'In %n minute on %1$s',
-				'In %n minutes on %1$s',
-				$occurrenceIn['interval'],
-				[$occurrence]
-			),
-			['hour', false, false] => $this->l10n->n(
-				'In %n hour on %1$s',
-				'In %n hours on %1$s',
-				$occurrenceIn['interval'],
-				[$occurrence]
-			),
-			['day', false, false] => $this->l10n->n(
-				'In %n day on %1$s',
-				'In %n days on %1$s',
-				$occurrenceIn['interval'],
-				[$occurrence]
-			),
-			['week', false, false] => $this->l10n->n(
-				'In %n week on %1$s',
-				'In %n weeks on %1$s',
-				$occurrenceIn['interval'],
-				[$occurrence]
-			),
-			['month', false, false] => $this->l10n->n(
-				'In %n month on %1$s',
-				'In %n months on %1$s',
-				$occurrenceIn['interval'],
-				[$occurrence]
-			),
-			['year', false, false] => $this->l10n->n(
-				'In %n year on %1$s',
-				'In %n years on %1$s',
-				$occurrenceIn['interval'],
-				[$occurrence]
-			),
-			['past', true, false] => $this->l10n->t(
-				'In the past on %1$s then on %2$s',
-				[$occurrence, $occurrence2]
-			),
-			['minute', true, false] => $this->l10n->n(
-				'In %n minute on %1$s then on %2$s',
-				'In %n minutes on %1$s then on %2$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2]
-			),
-			['hour', true, false] => $this->l10n->n(
-				'In %n hour on %1$s then on %2$s',
-				'In %n hours on %1$s then on %2$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2]
-			),
-			['day', true, false] => $this->l10n->n(
-				'In %n day on %1$s then on %2$s',
-				'In %n days on %1$s then on %2$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2]
-			),
-			['week', true, false] => $this->l10n->n(
-				'In %n week on %1$s then on %2$s',
-				'In %n weeks on %1$s then on %2$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2]
-			),
-			['month', true, false] => $this->l10n->n(
-				'In %n month on %1$s then on %2$s',
-				'In %n months on %1$s then on %2$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2]
-			),
-			['year', true, false] => $this->l10n->n(
-				'In %n year on %1$s then on %2$s',
-				'In %n years on %1$s then on %2$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2]
-			),
-			['past', true, true] => $this->l10n->t(
-				'In the past on %1$s then on %2$s and %3$s',
-				[$occurrence, $occurrence2, $occurrence3]
-			),
-			['minute', true, true] => $this->l10n->n(
-				'In %n minute on %1$s then on %2$s and %3$s',
-				'In %n minutes on %1$s then on %2$s and %3$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2, $occurrence3]
-			),
-			['hour', true, true] => $this->l10n->n(
-				'In %n hour on %1$s then on %2$s and %3$s',
-				'In %n hours on %1$s then on %2$s and %3$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2, $occurrence3]
-			),
-			['day', true, true] => $this->l10n->n(
-				'In %n day on %1$s then on %2$s and %3$s',
-				'In %n days on %1$s then on %2$s and %3$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2, $occurrence3]
-			),
-			['week', true, true] => $this->l10n->n(
-				'In %n week on %1$s then on %2$s and %3$s',
-				'In %n weeks on %1$s then on %2$s and %3$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2, $occurrence3]
-			),
-			['month', true, true] => $this->l10n->n(
-				'In %n month on %1$s then on %2$s and %3$s',
-				'In %n months on %1$s then on %2$s and %3$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2, $occurrence3]
-			),
-			['year', true, true] => $this->l10n->n(
-				'In %n year on %1$s then on %2$s and %3$s',
-				'In %n years on %1$s then on %2$s and %3$s',
-				$occurrenceIn['interval'],
-				[$occurrence, $occurrence2, $occurrence3]
-			),
-			default => $this->l10n->t('Could not generate next recurrence statement')
-		};
-
-	}
-
-	/**
-	 * @param VEvent $vEvent
-	 * @return array
-	 */
-	public function buildCancelledBodyData(VEvent $vEvent): array {
-		// construct event reader
-		$eventReaderCurrent = new EventReader($vEvent);
-		$defaultVal = '';
-		$strikethrough = "<span style='text-decoration: line-through'>%s</span>";
-
-		$newMeetingWhen = $this->generateWhenString($eventReaderCurrent);
-		$newSummary = htmlspecialchars(isset($vEvent->SUMMARY) && (string)$vEvent->SUMMARY !== '' ? (string)$vEvent->SUMMARY : $this->l10n->t('Untitled event'));
-		$newDescription = htmlspecialchars(isset($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;
-		$newLocation = htmlspecialchars(isset($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 $attendee
-	 */
-	public function setL10nFromAttendee(Property $attendee) {
-		$language = null;
-		$locale = null;
-		// check if the attendee is a system user
-		$userAddress = $attendee->getValue();
-		if (str_starts_with($userAddress, 'mailto:')) {
-			$userAddress = substr($userAddress, 7);
-		}
-		$users = $this->userManager->getByEmail($userAddress);
-		if ($users !== []) {
-			$user = array_shift($users);
-			$language = $this->config->getUserValue($user->getUID(), 'core', 'lang', null);
-			$locale = $this->config->getUserValue($user->getUID(), 'core', 'locale', null);
-		}
-		// fallback to attendee LANGUAGE parameter if language not set
-		if ($language === null && isset($attendee['LANGUAGE']) && $attendee['LANGUAGE'] instanceof Parameter) {
-			$language = $attendee['LANGUAGE']->getValue();
-		}
-		// fallback to system language if language not set
-		if ($language === null) {
-			$language = $this->l10nFactory->findGenericLanguage();
-		}
-		// fallback to system locale if locale not set
-		if ($locale === null) {
-			$locale = $this->l10nFactory->findLocale($language);
-		}
-		$this->l10n = $this->l10nFactory->get('dav', $language, $locale);
-	}
-
-	/**
-	 * @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(
-			$data['meeting_title_html'] ?? htmlspecialchars($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'] ?? htmlspecialchars($data['meeting_when']), $this->l10n->t('When:'),
-				$this->getAbsoluteImagePath('caldav/time.png'), $data['meeting_when'], '', IMipPlugin::IMIP_INDENT);
-		}
-		if ($data['meeting_location'] !== '') {
-			$template->addBodyListItem($data['meeting_location_html'] ?? htmlspecialchars($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'] ?? htmlspecialchars($data['meeting_url']), $this->l10n->t('Link:'),
-				$this->getAbsoluteImagePath('caldav/link.png'), $data['meeting_url'], '', IMipPlugin::IMIP_INDENT);
-		}
-		if (isset($data['meeting_occurring'])) {
-			$template->addBodyListItem($data['meeting_occurring_html'] ?? htmlspecialchars($data['meeting_occurring']), $this->l10n->t('Occurring:'),
-				$this->getAbsoluteImagePath('caldav/time.png'), $data['meeting_occurring'], '', 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'] ?? htmlspecialchars($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 $attendee) {
-			if ($iTipMessage->method === 'REPLY' && strcasecmp($attendee->getValue(), $iTipMessage->sender) === 0) {
-				/** @var Property $attendee */
-				return $attendee;
-			} elseif (strcasecmp($attendee->getValue(), $iTipMessage->recipient) === 0) {
-				/** @var Property $attendee */
-				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'}?->getValue();
-
-		$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)
-			])
-			->executeStatement();
-
-		return $token;
-	}
-
-	/**
-	 * @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'], true)) {
-			// Don't send emails to things
-			return true;
-		}
-		return false;
-	}
-
-	public function isCircle(Property $attendee): bool {
-		$cuType = $attendee->offsetGet('CUTYPE');
-		if (!$cuType instanceof Parameter) {
-			return false;
-		}
-
-		$uri = $attendee->getValue();
-		if (!$uri) {
-			return false;
-		}
-
-		$cuTypeValue = $cuType->getValue();
-		return $cuTypeValue === 'GROUP' && str_starts_with($uri, 'mailto:circle+');
-	}
-
-	public function minimizeInterval(\DateInterval $dateInterval): array {
-		// evaluate if time interval is in the past
-		if ($dateInterval->invert == 1) {
-			return ['interval' => 1, 'scale' => 'past'];
-		}
-		// evaluate interval parts and return smallest time period
-		if ($dateInterval->y > 0) {
-			$interval = $dateInterval->y;
-			$scale = 'year';
-		} elseif ($dateInterval->m > 0) {
-			$interval = $dateInterval->m;
-			$scale = 'month';
-		} elseif ($dateInterval->d >= 7) {
-			$interval = (int)($dateInterval->d / 7);
-			$scale = 'week';
-		} elseif ($dateInterval->d > 0) {
-			$interval = $dateInterval->d;
-			$scale = 'day';
-		} elseif ($dateInterval->h > 0) {
-			$interval = $dateInterval->h;
-			$scale = 'hour';
-		} else {
-			$interval = $dateInterval->i;
-			$scale = 'minute';
-		}
-
-		return ['interval' => $interval, 'scale' => $scale];
-	}
-
-	/**
-	 * Localizes week day names to another language
-	 *
-	 * @param string $value
-	 *
-	 * @return string
-	 */
-	public function localizeDayName(string $value): string {
-		return match ($value) {
-			'Monday' => $this->l10n->t('Monday'),
-			'Tuesday' => $this->l10n->t('Tuesday'),
-			'Wednesday' => $this->l10n->t('Wednesday'),
-			'Thursday' => $this->l10n->t('Thursday'),
-			'Friday' => $this->l10n->t('Friday'),
-			'Saturday' => $this->l10n->t('Saturday'),
-			'Sunday' => $this->l10n->t('Sunday'),
-		};
-	}
-
-	/**
-	 * Localizes month names to another language
-	 *
-	 * @param string $value
-	 *
-	 * @return string
-	 */
-	public function localizeMonthName(string $value): string {
-		return match ($value) {
-			'January' => $this->l10n->t('January'),
-			'February' => $this->l10n->t('February'),
-			'March' => $this->l10n->t('March'),
-			'April' => $this->l10n->t('April'),
-			'May' => $this->l10n->t('May'),
-			'June' => $this->l10n->t('June'),
-			'July' => $this->l10n->t('July'),
-			'August' => $this->l10n->t('August'),
-			'September' => $this->l10n->t('September'),
-			'October' => $this->l10n->t('October'),
-			'November' => $this->l10n->t('November'),
-			'December' => $this->l10n->t('December'),
-		};
-	}
-
-	/**
-	 * Localizes relative position names to another language
-	 *
-	 * @param string $value
-	 *
-	 * @return string
-	 */
-	public function localizeRelativePositionName(string $value): string {
-		return match ($value) {
-			'First' => $this->l10n->t('First'),
-			'Second' => $this->l10n->t('Second'),
-			'Third' => $this->l10n->t('Third'),
-			'Fourth' => $this->l10n->t('Fourth'),
-			'Fifth' => $this->l10n->t('Fifth'),
-			'Last' => $this->l10n->t('Last'),
-			'Second Last' => $this->l10n->t('Second Last'),
-			'Third Last' => $this->l10n->t('Third Last'),
-			'Fourth Last' => $this->l10n->t('Fourth Last'),
-			'Fifth Last' => $this->l10n->t('Fifth Last'),
-		};
-	}
+    private IL10N $l10n;
+
+    /** @var string[] */
+    private const STRING_DIFF = [
+        'meeting_title' => 'SUMMARY',
+        'meeting_description' => 'DESCRIPTION',
+        'meeting_url' => 'URL',
+        'meeting_location' => 'LOCATION'
+    ];
+
+    public function __construct(
+        private URLGenerator $urlGenerator,
+        private IConfig $config,
+        private IDBConnection $db,
+        private ISecureRandom $random,
+        private L10NFactory $l10nFactory,
+        private ITimeFactory $timeFactory,
+        private readonly IUserManager $userManager,
+    ) {
+        $language = $this->l10nFactory->findGenericLanguage();
+        $locale = $this->l10nFactory->findLocale($language);
+        $this->l10n = $this->l10nFactory->get('dav', $language, $locale);
+    }
+
+    /**
+     * @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;
+        }
+        $value = $vevent->$property->getValue();
+        $newstring = $value === null ? null : htmlspecialchars($value);
+        if (isset($oldVEvent->$property) && $oldVEvent->$property->getValue() !== $newstring) {
+            $oldstring = $oldVEvent->$property->getValue();
+            return sprintf($strikethrough, htmlspecialchars($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 */
+        $newString = htmlspecialchars($vevent->$property->getValue());
+        $oldString = isset($oldVEvent->$property) ? htmlspecialchars($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 {
+
+        // construct event reader
+        $eventReaderCurrent = new EventReader($vEvent);
+        $eventReaderPrevious = !empty($oldVEvent) ? new EventReader($oldVEvent) : null;
+        $defaultVal = '';
+        $data = [];
+        $data['meeting_when'] = $this->generateWhenString($eventReaderCurrent);
+
+        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 = $this->generateWhenString($eventReaderPrevious);
+            $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'] ? sprintf("<span style='text-decoration: line-through'>%s</span><br />%s", $oldMeetingWhen, $data['meeting_when']) : $data['meeting_when'];
+        }
+        // generate occurring next string
+        if ($eventReaderCurrent->recurs()) {
+            $data['meeting_occurring'] = $this->generateOccurringString($eventReaderCurrent);
+        }
+        return $data;
+    }
+
+    /**
+     * @param VEvent $vEvent
+     * @return array
+     */
+    public function buildReplyBodyData(VEvent $vEvent): array {
+        // construct event reader
+        $eventReader = new EventReader($vEvent);
+        $defaultVal = '';
+        $data = [];
+        $data['meeting_when'] = $this->generateWhenString($eventReader);
+
+        foreach (self::STRING_DIFF as $key => $property) {
+            $data[$key] = self::readPropertyWithDefault($vEvent, $property, $defaultVal);
+        }
+
+        if (($locationHtml = $this->linkify($data['meeting_location'])) !== null) {
+            $data['meeting_location_html'] = $locationHtml;
+        }
+
+        $data['meeting_url_html'] = $data['meeting_url'] ? sprintf('<a href="%1$s">%1$s</a>', $data['meeting_url']) : '';
+
+        // generate occurring next string
+        if ($eventReader->recurs()) {
+            $data['meeting_occurring'] = $this->generateOccurringString($eventReader);
+        }
+
+        return $data;
+    }
+
+    /**
+     * generates a when string based on if a event has an recurrence or not
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateWhenString(EventReader $er): string {
+        return match ($er->recurs()) {
+            true => $this->generateWhenStringRecurring($er),
+            false => $this->generateWhenStringSingular($er)
+        };
+    }
+
+    /**
+     * generates a when string for a non recurring event
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateWhenStringSingular(EventReader $er): string {
+        // initialize
+        $startTime = null;
+        $endTime = null;
+        // calculate time difference from now to start of event
+        $occurring = $this->minimizeInterval($this->timeFactory->getDateTime()->diff($er->recurrenceDate()));
+        // extract start date
+        $startDate = $this->l10n->l('date', $er->startDateTime(), ['width' => 'full']);
+        // time of the day
+        if (!$er->entireDay()) {
+            $startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
+            $startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
+            $endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+        }
+        // generate localized when string
+        // TRANSLATORS
+        // Indicates when a calendar event will happen, shown on invitation emails
+        // Output produced in order:
+        // In 1 minute/hour/day/week/month/year on July 1, 2024 for the entire day
+        // In 1 minute/hour/day/week/month/year on July 1, 2024 between 8:00 AM - 9:00 AM (America/Toronto)
+        // In 2 minutes/hours/days/weeks/months/years on July 1, 2024 for the entire day
+        // In 2 minutes/hours/days/weeks/months/years on July 1, 2024 between 8:00 AM - 9:00 AM (America/Toronto)
+        return match ([$occurring['scale'], $endTime !== null]) {
+            ['past', false] => $this->l10n->t(
+                'In the past on %1$s for the entire day',
+                [$startDate]
+            ),
+            ['minute', false] => $this->l10n->n(
+                'In %n minute on %1$s for the entire day',
+                'In %n minutes on %1$s for the entire day',
+                $occurring['interval'],
+                [$startDate]
+            ),
+            ['hour', false] => $this->l10n->n(
+                'In %n hour on %1$s for the entire day',
+                'In %n hours on %1$s for the entire day',
+                $occurring['interval'],
+                [$startDate]
+            ),
+            ['day', false] => $this->l10n->n(
+                'In %n day on %1$s for the entire day',
+                'In %n days on %1$s for the entire day',
+                $occurring['interval'],
+                [$startDate]
+            ),
+            ['week', false] => $this->l10n->n(
+                'In %n week on %1$s for the entire day',
+                'In %n weeks on %1$s for the entire day',
+                $occurring['interval'],
+                [$startDate]
+            ),
+            ['month', false] => $this->l10n->n(
+                'In %n month on %1$s for the entire day',
+                'In %n months on %1$s for the entire day',
+                $occurring['interval'],
+                [$startDate]
+            ),
+            ['year', false] => $this->l10n->n(
+                'In %n year on %1$s for the entire day',
+                'In %n years on %1$s for the entire day',
+                $occurring['interval'],
+                [$startDate]
+            ),
+            ['past', true] => $this->l10n->t(
+                'In the past on %1$s between %2$s - %3$s',
+                [$startDate, $startTime, $endTime]
+            ),
+            ['minute', true] => $this->l10n->n(
+                'In %n minute on %1$s between %2$s - %3$s',
+                'In %n minutes on %1$s between %2$s - %3$s',
+                $occurring['interval'],
+                [$startDate, $startTime, $endTime]
+            ),
+            ['hour', true] => $this->l10n->n(
+                'In %n hour on %1$s between %2$s - %3$s',
+                'In %n hours on %1$s between %2$s - %3$s',
+                $occurring['interval'],
+                [$startDate, $startTime, $endTime]
+            ),
+            ['day', true] => $this->l10n->n(
+                'In %n day on %1$s between %2$s - %3$s',
+                'In %n days on %1$s between %2$s - %3$s',
+                $occurring['interval'],
+                [$startDate, $startTime, $endTime]
+            ),
+            ['week', true] => $this->l10n->n(
+                'In %n week on %1$s between %2$s - %3$s',
+                'In %n weeks on %1$s between %2$s - %3$s',
+                $occurring['interval'],
+                [$startDate, $startTime, $endTime]
+            ),
+            ['month', true] => $this->l10n->n(
+                'In %n month on %1$s between %2$s - %3$s',
+                'In %n months on %1$s between %2$s - %3$s',
+                $occurring['interval'],
+                [$startDate, $startTime, $endTime]
+            ),
+            ['year', true] => $this->l10n->n(
+                'In %n year on %1$s between %2$s - %3$s',
+                'In %n years on %1$s between %2$s - %3$s',
+                $occurring['interval'],
+                [$startDate, $startTime, $endTime]
+            ),
+            default => $this->l10n->t('Could not generate when statement')
+        };
+    }
+
+    /**
+     * generates a when string based on recurrence precision/frequency
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateWhenStringRecurring(EventReader $er): string {
+        return match ($er->recurringPrecision()) {
+            'daily' => $this->generateWhenStringRecurringDaily($er),
+            'weekly' => $this->generateWhenStringRecurringWeekly($er),
+            'monthly' => $this->generateWhenStringRecurringMonthly($er),
+            'yearly' => $this->generateWhenStringRecurringYearly($er),
+            'fixed' => $this->generateWhenStringRecurringFixed($er),
+        };
+    }
+
+    /**
+     * generates a when string for a daily precision/frequency
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateWhenStringRecurringDaily(EventReader $er): string {
+
+        // initialize
+        $interval = (int)$er->recurringInterval();
+        $startTime = null;
+        $conclusion = null;
+        // time of the day
+        if (!$er->entireDay()) {
+            $startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
+            $startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
+            $endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+        }
+        // conclusion
+        if ($er->recurringConcludes()) {
+            $conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
+        }
+        // generate localized when string
+        // TRANSLATORS
+        // Indicates when a calendar event will happen, shown on invitation emails
+        // Output produced in order:
+        // Every Day for the entire day
+        // Every Day for the entire day until July 13, 2024
+        // Every Day between 8:00 AM - 9:00 AM (America/Toronto)
+        // Every Day between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
+        // Every 3 Days for the entire day
+        // Every 3 Days for the entire day until July 13, 2024
+        // Every 3 Days between 8:00 AM - 9:00 AM (America/Toronto)
+        // Every 3 Days between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
+        return match ([($interval > 1), $startTime !== null, $conclusion !== null]) {
+            [false, false, false] => $this->l10n->t('Every Day for the entire day'),
+            [false, false, true] => $this->l10n->t('Every Day for the entire day until %1$s', [$conclusion]),
+            [false, true, false] => $this->l10n->t('Every Day between %1$s - %2$s', [$startTime, $endTime]),
+            [false, true, true] => $this->l10n->t('Every Day between %1$s - %2$s until %3$s', [$startTime, $endTime, $conclusion]),
+            [true, false, false] => $this->l10n->t('Every %1$d Days for the entire day', [$interval]),
+            [true, false, true] => $this->l10n->t('Every %1$d Days for the entire day until %2$s', [$interval, $conclusion]),
+            [true, true, false] => $this->l10n->t('Every %1$d Days between %2$s - %3$s', [$interval, $startTime, $endTime]),
+            [true, true, true] => $this->l10n->t('Every %1$d Days between %2$s - %3$s until %4$s', [$interval, $startTime, $endTime, $conclusion]),
+            default => $this->l10n->t('Could not generate event recurrence statement')
+        };
+
+    }
+
+    /**
+     * generates a when string for a weekly precision/frequency
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateWhenStringRecurringWeekly(EventReader $er): string {
+
+        // initialize
+        $interval = (int)$er->recurringInterval();
+        $startTime = null;
+        $conclusion = null;
+        // days of the week
+        $days = implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
+        // time of the day
+        if (!$er->entireDay()) {
+            $startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
+            $startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
+            $endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+        }
+        // conclusion
+        if ($er->recurringConcludes()) {
+            $conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
+        }
+        // generate localized when string
+        // TRANSLATORS
+        // Indicates when a calendar event will happen, shown on invitation emails
+        // Output produced in order:
+        // Every Week on Monday, Wednesday, Friday for the entire day
+        // Every Week on Monday, Wednesday, Friday for the entire day until July 13, 2024
+        // Every Week on Monday, Wednesday, Friday between 8:00 AM - 9:00 AM (America/Toronto)
+        // Every Week on Monday, Wednesday, Friday between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
+        // Every 2 Weeks on Monday, Wednesday, Friday for the entire day
+        // Every 2 Weeks on Monday, Wednesday, Friday for the entire day until July 13, 2024
+        // Every 2 Weeks on Monday, Wednesday, Friday between 8:00 AM - 9:00 AM (America/Toronto)
+        // Every 2 Weeks on Monday, Wednesday, Friday between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
+        return match ([($interval > 1), $startTime !== null, $conclusion !== null]) {
+            [false, false, false] => $this->l10n->t('Every Week on %1$s for the entire day', [$days]),
+            [false, false, true] => $this->l10n->t('Every Week on %1$s for the entire day until %2$s', [$days, $conclusion]),
+            [false, true, false] => $this->l10n->t('Every Week on %1$s between %2$s - %3$s', [$days, $startTime, $endTime]),
+            [false, true, true] => $this->l10n->t('Every Week on %1$s between %2$s - %3$s until %4$s', [$days, $startTime, $endTime, $conclusion]),
+            [true, false, false] => $this->l10n->t('Every %1$d Weeks on %2$s for the entire day', [$interval, $days]),
+            [true, false, true] => $this->l10n->t('Every %1$d Weeks on %2$s for the entire day until %3$s', [$interval, $days, $conclusion]),
+            [true, true, false] => $this->l10n->t('Every %1$d Weeks on %2$s between %3$s - %4$s', [$interval, $days, $startTime, $endTime]),
+            [true, true, true] => $this->l10n->t('Every %1$d Weeks on %2$s between %3$s - %4$s until %5$s', [$interval, $days, $startTime, $endTime, $conclusion]),
+            default => $this->l10n->t('Could not generate event recurrence statement')
+        };
+
+    }
+
+    /**
+     * generates a when string for a monthly precision/frequency
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateWhenStringRecurringMonthly(EventReader $er): string {
+
+        // initialize
+        $interval = (int)$er->recurringInterval();
+        $startTime = null;
+        $conclusion = null;
+        // days of month
+        if ($er->recurringPattern() === 'R') {
+            $days = implode(', ', array_map(function ($value) { return $this->localizeRelativePositionName($value); }, $er->recurringRelativePositionNamed())) . ' '
+                    . implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
+        } else {
+            $days = implode(', ', $er->recurringDaysOfMonth());
+        }
+        // time of the day
+        if (!$er->entireDay()) {
+            $startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
+            $startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
+            $endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+        }
+        // conclusion
+        if ($er->recurringConcludes()) {
+            $conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
+        }
+        // generate localized when string
+        // TRANSLATORS
+        // Indicates when a calendar event will happen, shown on invitation emails
+        // Output produced in order, output varies depending on if the event is absolute or releative:
+        // Absolute: Every Month on the 1, 8 for the entire day
+        // Relative: Every Month on the First Sunday, Saturday for the entire day
+        // Absolute: Every Month on the 1, 8 for the entire day until December 31, 2024
+        // Relative: Every Month on the First Sunday, Saturday for the entire day until December 31, 2024
+        // Absolute: Every Month on the 1, 8 between 8:00 AM - 9:00 AM (America/Toronto)
+        // Relative: Every Month on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto)
+        // Absolute: Every Month on the 1, 8 between 8:00 AM - 9:00 AM (America/Toronto) until December 31, 2024
+        // Relative: Every Month on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto) until December 31, 2024
+        // Absolute: Every 2 Months on the 1, 8 for the entire day
+        // Relative: Every 2 Months on the First Sunday, Saturday for the entire day
+        // Absolute: Every 2 Months on the 1, 8 for the entire day until December 31, 2024
+        // Relative: Every 2 Months on the First Sunday, Saturday for the entire day until December 31, 2024
+        // Absolute: Every 2 Months on the 1, 8 between 8:00 AM - 9:00 AM (America/Toronto)
+        // Relative: Every 2 Months on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto)
+        // Absolute: Every 2 Months on the 1, 8 between 8:00 AM - 9:00 AM (America/Toronto) until December 31, 2024
+        // Relative: Every 2 Months on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto) until December 31, 2024
+        return match ([($interval > 1), $startTime !== null, $conclusion !== null]) {
+            [false, false, false] => $this->l10n->t('Every Month on the %1$s for the entire day', [$days]),
+            [false, false, true] => $this->l10n->t('Every Month on the %1$s for the entire day until %2$s', [$days, $conclusion]),
+            [false, true, false] => $this->l10n->t('Every Month on the %1$s between %2$s - %3$s', [$days, $startTime, $endTime]),
+            [false, true, true] => $this->l10n->t('Every Month on the %1$s between %2$s - %3$s until %4$s', [$days, $startTime, $endTime, $conclusion]),
+            [true, false, false] => $this->l10n->t('Every %1$d Months on the %2$s for the entire day', [$interval, $days]),
+            [true, false, true] => $this->l10n->t('Every %1$d Months on the %2$s for the entire day until %3$s', [$interval, $days, $conclusion]),
+            [true, true, false] => $this->l10n->t('Every %1$d Months on the %2$s between %3$s - %4$s', [$interval, $days, $startTime, $endTime]),
+            [true, true, true] => $this->l10n->t('Every %1$d Months on the %2$s between %3$s - %4$s until %5$s', [$interval, $days, $startTime, $endTime, $conclusion]),
+            default => $this->l10n->t('Could not generate event recurrence statement')
+        };
+    }
+
+    /**
+     * generates a when string for a yearly precision/frequency
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateWhenStringRecurringYearly(EventReader $er): string {
+
+        // initialize
+        $interval = (int)$er->recurringInterval();
+        $startTime = null;
+        $conclusion = null;
+        // months of year
+        $months = implode(', ', array_map(function ($value) { return $this->localizeMonthName($value); }, $er->recurringMonthsOfYearNamed()));
+        // days of month
+        if ($er->recurringPattern() === 'R') {
+            $days = implode(', ', array_map(function ($value) { return $this->localizeRelativePositionName($value); }, $er->recurringRelativePositionNamed())) . ' '
+                    . implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
+        } else {
+            $days = $er->startDateTime()->format('jS');
+        }
+        // time of the day
+        if (!$er->entireDay()) {
+            $startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
+            $startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
+            $endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+        }
+        // conclusion
+        if ($er->recurringConcludes()) {
+            $conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
+        }
+        // generate localized when string
+        // TRANSLATORS
+        // Indicates when a calendar event will happen, shown on invitation emails
+        // Output produced in order, output varies depending on if the event is absolute or releative:
+        // Absolute: Every Year in July on the 1st for the entire day
+        // Relative: Every Year in July on the First Sunday, Saturday for the entire day
+        // Absolute: Every Year in July on the 1st for the entire day until July 31, 2026
+        // Relative: Every Year in July on the First Sunday, Saturday for the entire day until July 31, 2026
+        // Absolute: Every Year in July on the 1st between 8:00 AM - 9:00 AM (America/Toronto)
+        // Relative: Every Year in July on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto)
+        // Absolute: Every Year in July on the 1st between 8:00 AM - 9:00 AM (America/Toronto) until July 31, 2026
+        // Relative: Every Year in July on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto) until July 31, 2026
+        // Absolute: Every 2 Years in July on the 1st for the entire day
+        // Relative: Every 2 Years in July on the First Sunday, Saturday for the entire day
+        // Absolute: Every 2 Years in July on the 1st for the entire day until July 31, 2026
+        // Relative: Every 2 Years in July on the First Sunday, Saturday for the entire day until July 31, 2026
+        // Absolute: Every 2 Years in July on the 1st between 8:00 AM - 9:00 AM (America/Toronto)
+        // Relative: Every 2 Years in July on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto)
+        // Absolute: Every 2 Years in July on the 1st between 8:00 AM - 9:00 AM (America/Toronto) until July 31, 2026
+        // Relative: Every 2 Years in July on the First Sunday, Saturday between 8:00 AM - 9:00 AM (America/Toronto) until July 31, 2026
+        return match ([($interval > 1), $startTime !== null, $conclusion !== null]) {
+            [false, false, false] => $this->l10n->t('Every Year in %1$s on the %2$s for the entire day', [$months, $days]),
+            [false, false, true] => $this->l10n->t('Every Year in %1$s on the %2$s for the entire day until %3$s', [$months, $days, $conclusion]),
+            [false, true, false] => $this->l10n->t('Every Year in %1$s on the %2$s between %3$s - %4$s', [$months, $days, $startTime, $endTime]),
+            [false, true, true] => $this->l10n->t('Every Year in %1$s on the %2$s between %3$s - %4$s until %5$s', [$months, $days, $startTime, $endTime, $conclusion]),
+            [true, false, false] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s for the entire day', [$interval, $months, $days]),
+            [true, false, true] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s for the entire day until %4$s', [$interval, $months,  $days, $conclusion]),
+            [true, true, false] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s between %4$s - %5$s', [$interval, $months, $days, $startTime, $endTime]),
+            [true, true, true] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s between %4$s - %5$s until %6$s', [$interval, $months, $days, $startTime, $endTime, $conclusion]),
+            default => $this->l10n->t('Could not generate event recurrence statement')
+        };
+    }
+
+    /**
+     * generates a when string for a fixed precision/frequency
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateWhenStringRecurringFixed(EventReader $er): string {
+        // initialize
+        $startTime = null;
+        $conclusion = null;
+        // time of the day
+        if (!$er->entireDay()) {
+            $startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
+            $startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
+            $endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+        }
+        // conclusion
+        $conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
+        // generate localized when string
+        // TRANSLATORS
+        // Indicates when a calendar event will happen, shown on invitation emails
+        // Output produced in order:
+        // On specific dates for the entire day until July 13, 2024
+        // On specific dates between 8:00 AM - 9:00 AM (America/Toronto) until July 13, 2024
+        return match ($startTime !== null) {
+            false => $this->l10n->t('On specific dates for the entire day until %1$s', [$conclusion]),
+            true => $this->l10n->t('On specific dates between %1$s - %2$s until %3$s', [$startTime, $endTime, $conclusion]),
+        };
+    }
+
+    /**
+     * generates a occurring next string for a recurring event
+     *
+     * @since 30.0.0
+     *
+     * @param EventReader $er
+     *
+     * @return string
+     */
+    public function generateOccurringString(EventReader $er): string {
+
+        // initialize
+        $occurrence = null;
+        $occurrence2 = null;
+        $occurrence3 = null;
+        // reset to initial occurrence
+        $er->recurrenceRewind();
+        // forward to current date
+        $er->recurrenceAdvanceTo($this->timeFactory->getDateTime());
+        // calculate time difference from now to start of next event occurrence and minimize it
+        $occurrenceIn = $this->minimizeInterval($this->timeFactory->getDateTime()->diff($er->recurrenceDate()));
+        // store next occurrence value
+        $occurrence = $this->l10n->l('date', $er->recurrenceDate(), ['width' => 'long']);
+        // forward one occurrence
+        $er->recurrenceAdvance();
+        // evaluate if occurrence is valid
+        if ($er->recurrenceDate() !== null) {
+            // store following occurrence value
+            $occurrence2 = $this->l10n->l('date', $er->recurrenceDate(), ['width' => 'long']);
+            // forward one occurrence
+            $er->recurrenceAdvance();
+            // evaluate if occurrence is valid
+            if ($er->recurrenceDate()) {
+                // store following occurrence value
+                $occurrence3 = $this->l10n->l('date', $er->recurrenceDate(), ['width' => 'long']);
+            }
+        }
+        // generate localized when string
+        // TRANSLATORS
+        // Indicates when a calendar event will happen, shown on invitation emails
+        // Output produced in order:
+        // In 1 minute/hour/day/week/month/year on July 1, 2024
+        // In 1 minute/hour/day/week/month/year on July 1, 2024 then on July 3, 2024
+        // In 1 minute/hour/day/week/month/year on July 1, 2024 then on July 3, 2024 and July 5, 2024
+        // In 2 minutes/hours/days/weeks/months/years on July 1, 2024
+        // In 2 minutes/hours/days/weeks/months/years on July 1, 2024 then on July 3, 2024
+        // In 2 minutes/hours/days/weeks/months/years on July 1, 2024 then on July 3, 2024 and July 5, 2024
+        return match ([$occurrenceIn['scale'], $occurrence2 !== null, $occurrence3 !== null]) {
+            ['past', false, false] => $this->l10n->t(
+                'In the past on %1$s',
+                [$occurrence]
+            ),
+            ['minute', false, false] => $this->l10n->n(
+                'In %n minute on %1$s',
+                'In %n minutes on %1$s',
+                $occurrenceIn['interval'],
+                [$occurrence]
+            ),
+            ['hour', false, false] => $this->l10n->n(
+                'In %n hour on %1$s',
+                'In %n hours on %1$s',
+                $occurrenceIn['interval'],
+                [$occurrence]
+            ),
+            ['day', false, false] => $this->l10n->n(
+                'In %n day on %1$s',
+                'In %n days on %1$s',
+                $occurrenceIn['interval'],
+                [$occurrence]
+            ),
+            ['week', false, false] => $this->l10n->n(
+                'In %n week on %1$s',
+                'In %n weeks on %1$s',
+                $occurrenceIn['interval'],
+                [$occurrence]
+            ),
+            ['month', false, false] => $this->l10n->n(
+                'In %n month on %1$s',
+                'In %n months on %1$s',
+                $occurrenceIn['interval'],
+                [$occurrence]
+            ),
+            ['year', false, false] => $this->l10n->n(
+                'In %n year on %1$s',
+                'In %n years on %1$s',
+                $occurrenceIn['interval'],
+                [$occurrence]
+            ),
+            ['past', true, false] => $this->l10n->t(
+                'In the past on %1$s then on %2$s',
+                [$occurrence, $occurrence2]
+            ),
+            ['minute', true, false] => $this->l10n->n(
+                'In %n minute on %1$s then on %2$s',
+                'In %n minutes on %1$s then on %2$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2]
+            ),
+            ['hour', true, false] => $this->l10n->n(
+                'In %n hour on %1$s then on %2$s',
+                'In %n hours on %1$s then on %2$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2]
+            ),
+            ['day', true, false] => $this->l10n->n(
+                'In %n day on %1$s then on %2$s',
+                'In %n days on %1$s then on %2$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2]
+            ),
+            ['week', true, false] => $this->l10n->n(
+                'In %n week on %1$s then on %2$s',
+                'In %n weeks on %1$s then on %2$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2]
+            ),
+            ['month', true, false] => $this->l10n->n(
+                'In %n month on %1$s then on %2$s',
+                'In %n months on %1$s then on %2$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2]
+            ),
+            ['year', true, false] => $this->l10n->n(
+                'In %n year on %1$s then on %2$s',
+                'In %n years on %1$s then on %2$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2]
+            ),
+            ['past', true, true] => $this->l10n->t(
+                'In the past on %1$s then on %2$s and %3$s',
+                [$occurrence, $occurrence2, $occurrence3]
+            ),
+            ['minute', true, true] => $this->l10n->n(
+                'In %n minute on %1$s then on %2$s and %3$s',
+                'In %n minutes on %1$s then on %2$s and %3$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2, $occurrence3]
+            ),
+            ['hour', true, true] => $this->l10n->n(
+                'In %n hour on %1$s then on %2$s and %3$s',
+                'In %n hours on %1$s then on %2$s and %3$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2, $occurrence3]
+            ),
+            ['day', true, true] => $this->l10n->n(
+                'In %n day on %1$s then on %2$s and %3$s',
+                'In %n days on %1$s then on %2$s and %3$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2, $occurrence3]
+            ),
+            ['week', true, true] => $this->l10n->n(
+                'In %n week on %1$s then on %2$s and %3$s',
+                'In %n weeks on %1$s then on %2$s and %3$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2, $occurrence3]
+            ),
+            ['month', true, true] => $this->l10n->n(
+                'In %n month on %1$s then on %2$s and %3$s',
+                'In %n months on %1$s then on %2$s and %3$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2, $occurrence3]
+            ),
+            ['year', true, true] => $this->l10n->n(
+                'In %n year on %1$s then on %2$s and %3$s',
+                'In %n years on %1$s then on %2$s and %3$s',
+                $occurrenceIn['interval'],
+                [$occurrence, $occurrence2, $occurrence3]
+            ),
+            default => $this->l10n->t('Could not generate next recurrence statement')
+        };
+
+    }
+
+    /**
+     * @param VEvent $vEvent
+     * @return array
+     */
+    public function buildCancelledBodyData(VEvent $vEvent): array {
+        // construct event reader
+        $eventReaderCurrent = new EventReader($vEvent);
+        $defaultVal = '';
+        $strikethrough = "<span style='text-decoration: line-through'>%s</span>";
+
+        $newMeetingWhen = $this->generateWhenString($eventReaderCurrent);
+        $newSummary = htmlspecialchars(isset($vEvent->SUMMARY) && (string)$vEvent->SUMMARY !== '' ? (string)$vEvent->SUMMARY : $this->l10n->t('Untitled event'));
+        $newDescription = htmlspecialchars(isset($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;
+        $newLocation = htmlspecialchars(isset($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 $attendee
+     */
+    public function setL10nFromAttendee(Property $attendee) {
+        $language = null;
+        $locale = null;
+        // check if the attendee is a system user
+        $userAddress = $attendee->getValue();
+        if (str_starts_with($userAddress, 'mailto:')) {
+            $userAddress = substr($userAddress, 7);
+        }
+        $users = $this->userManager->getByEmail($userAddress);
+        if ($users !== []) {
+            $user = array_shift($users);
+            $language = $this->config->getUserValue($user->getUID(), 'core', 'lang', null);
+            $locale = $this->config->getUserValue($user->getUID(), 'core', 'locale', null);
+        }
+        // fallback to attendee LANGUAGE parameter if language not set
+        if ($language === null && isset($attendee['LANGUAGE']) && $attendee['LANGUAGE'] instanceof Parameter) {
+            $language = $attendee['LANGUAGE']->getValue();
+        }
+        // fallback to system language if language not set
+        if ($language === null) {
+            $language = $this->l10nFactory->findGenericLanguage();
+        }
+        // fallback to system locale if locale not set
+        if ($locale === null) {
+            $locale = $this->l10nFactory->findLocale($language);
+        }
+        $this->l10n = $this->l10nFactory->get('dav', $language, $locale);
+    }
+
+    /**
+     * @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(
+            $data['meeting_title_html'] ?? htmlspecialchars($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'] ?? htmlspecialchars($data['meeting_when']), $this->l10n->t('When:'),
+                $this->getAbsoluteImagePath('caldav/time.png'), $data['meeting_when'], '', IMipPlugin::IMIP_INDENT);
+        }
+        if ($data['meeting_location'] !== '') {
+            $template->addBodyListItem($data['meeting_location_html'] ?? htmlspecialchars($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'] ?? htmlspecialchars($data['meeting_url']), $this->l10n->t('Link:'),
+                $this->getAbsoluteImagePath('caldav/link.png'), $data['meeting_url'], '', IMipPlugin::IMIP_INDENT);
+        }
+        if (isset($data['meeting_occurring'])) {
+            $template->addBodyListItem($data['meeting_occurring_html'] ?? htmlspecialchars($data['meeting_occurring']), $this->l10n->t('Occurring:'),
+                $this->getAbsoluteImagePath('caldav/time.png'), $data['meeting_occurring'], '', 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'] ?? htmlspecialchars($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 $attendee) {
+            if ($iTipMessage->method === 'REPLY' && strcasecmp($attendee->getValue(), $iTipMessage->sender) === 0) {
+                /** @var Property $attendee */
+                return $attendee;
+            } elseif (strcasecmp($attendee->getValue(), $iTipMessage->recipient) === 0) {
+                /** @var Property $attendee */
+                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'}?->getValue();
+
+        $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)
+            ])
+            ->executeStatement();
+
+        return $token;
+    }
+
+    /**
+     * @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'], true)) {
+            // Don't send emails to things
+            return true;
+        }
+        return false;
+    }
+
+    public function isCircle(Property $attendee): bool {
+        $cuType = $attendee->offsetGet('CUTYPE');
+        if (!$cuType instanceof Parameter) {
+            return false;
+        }
+
+        $uri = $attendee->getValue();
+        if (!$uri) {
+            return false;
+        }
+
+        $cuTypeValue = $cuType->getValue();
+        return $cuTypeValue === 'GROUP' && str_starts_with($uri, 'mailto:circle+');
+    }
+
+    public function minimizeInterval(\DateInterval $dateInterval): array {
+        // evaluate if time interval is in the past
+        if ($dateInterval->invert == 1) {
+            return ['interval' => 1, 'scale' => 'past'];
+        }
+        // evaluate interval parts and return smallest time period
+        if ($dateInterval->y > 0) {
+            $interval = $dateInterval->y;
+            $scale = 'year';
+        } elseif ($dateInterval->m > 0) {
+            $interval = $dateInterval->m;
+            $scale = 'month';
+        } elseif ($dateInterval->d >= 7) {
+            $interval = (int)($dateInterval->d / 7);
+            $scale = 'week';
+        } elseif ($dateInterval->d > 0) {
+            $interval = $dateInterval->d;
+            $scale = 'day';
+        } elseif ($dateInterval->h > 0) {
+            $interval = $dateInterval->h;
+            $scale = 'hour';
+        } else {
+            $interval = $dateInterval->i;
+            $scale = 'minute';
+        }
+
+        return ['interval' => $interval, 'scale' => $scale];
+    }
+
+    /**
+     * Localizes week day names to another language
+     *
+     * @param string $value
+     *
+     * @return string
+     */
+    public function localizeDayName(string $value): string {
+        return match ($value) {
+            'Monday' => $this->l10n->t('Monday'),
+            'Tuesday' => $this->l10n->t('Tuesday'),
+            'Wednesday' => $this->l10n->t('Wednesday'),
+            'Thursday' => $this->l10n->t('Thursday'),
+            'Friday' => $this->l10n->t('Friday'),
+            'Saturday' => $this->l10n->t('Saturday'),
+            'Sunday' => $this->l10n->t('Sunday'),
+        };
+    }
+
+    /**
+     * Localizes month names to another language
+     *
+     * @param string $value
+     *
+     * @return string
+     */
+    public function localizeMonthName(string $value): string {
+        return match ($value) {
+            'January' => $this->l10n->t('January'),
+            'February' => $this->l10n->t('February'),
+            'March' => $this->l10n->t('March'),
+            'April' => $this->l10n->t('April'),
+            'May' => $this->l10n->t('May'),
+            'June' => $this->l10n->t('June'),
+            'July' => $this->l10n->t('July'),
+            'August' => $this->l10n->t('August'),
+            'September' => $this->l10n->t('September'),
+            'October' => $this->l10n->t('October'),
+            'November' => $this->l10n->t('November'),
+            'December' => $this->l10n->t('December'),
+        };
+    }
+
+    /**
+     * Localizes relative position names to another language
+     *
+     * @param string $value
+     *
+     * @return string
+     */
+    public function localizeRelativePositionName(string $value): string {
+        return match ($value) {
+            'First' => $this->l10n->t('First'),
+            'Second' => $this->l10n->t('Second'),
+            'Third' => $this->l10n->t('Third'),
+            'Fourth' => $this->l10n->t('Fourth'),
+            'Fifth' => $this->l10n->t('Fifth'),
+            'Last' => $this->l10n->t('Last'),
+            'Second Last' => $this->l10n->t('Second Last'),
+            'Third Last' => $this->l10n->t('Third Last'),
+            'Fourth Last' => $this->l10n->t('Fourth Last'),
+            'Fifth Last' => $this->l10n->t('Fifth Last'),
+        };
+    }
 }

Spacing +31 added lines, -31 removed lines

@@ -231,8 +231,8 @@ 
 		// time of the day
 		if (!$er->entireDay()) {
 			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' ('.$er->startTimeZone()->getName().')' : '';
+			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']).' ('.$er->endTimeZone()->getName().')';
 		}
 		// generate localized when string
 		// TRANSLATORS
@@ -358,14 +358,14 @@ 
 	public function generateWhenStringRecurringDaily(EventReader $er): string {
 
 		// initialize
-		$interval = (int)$er->recurringInterval();
+		$interval = (int) $er->recurringInterval();
 		$startTime = null;
 		$conclusion = null;
 		// time of the day
 		if (!$er->entireDay()) {
 			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' ('.$er->startTimeZone()->getName().')' : '';
+			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']).' ('.$er->endTimeZone()->getName().')';
 		}
 		// conclusion
 		if ($er->recurringConcludes()) {
@@ -409,16 +409,16 @@ 
 	public function generateWhenStringRecurringWeekly(EventReader $er): string {
 
 		// initialize
-		$interval = (int)$er->recurringInterval();
+		$interval = (int) $er->recurringInterval();
 		$startTime = null;
 		$conclusion = null;
 		// days of the week
-		$days = implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
+		$days = implode(', ', array_map(function($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
 		// time of the day
 		if (!$er->entireDay()) {
 			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' ('.$er->startTimeZone()->getName().')' : '';
+			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']).' ('.$er->endTimeZone()->getName().')';
 		}
 		// conclusion
 		if ($er->recurringConcludes()) {
@@ -462,21 +462,21 @@ 
 	public function generateWhenStringRecurringMonthly(EventReader $er): string {
 
 		// initialize
-		$interval = (int)$er->recurringInterval();
+		$interval = (int) $er->recurringInterval();
 		$startTime = null;
 		$conclusion = null;
 		// days of month
 		if ($er->recurringPattern() === 'R') {
-			$days = implode(', ', array_map(function ($value) { return $this->localizeRelativePositionName($value); }, $er->recurringRelativePositionNamed())) . ' '
-					. implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
+			$days = implode(', ', array_map(function($value) { return $this->localizeRelativePositionName($value); }, $er->recurringRelativePositionNamed())).' '
+					. implode(', ', array_map(function($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
 		} else {
 			$days = implode(', ', $er->recurringDaysOfMonth());
 		}
 		// time of the day
 		if (!$er->entireDay()) {
 			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' ('.$er->startTimeZone()->getName().')' : '';
+			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']).' ('.$er->endTimeZone()->getName().')';
 		}
 		// conclusion
 		if ($er->recurringConcludes()) {
@@ -527,23 +527,23 @@ 
 	public function generateWhenStringRecurringYearly(EventReader $er): string {
 
 		// initialize
-		$interval = (int)$er->recurringInterval();
+		$interval = (int) $er->recurringInterval();
 		$startTime = null;
 		$conclusion = null;
 		// months of year
-		$months = implode(', ', array_map(function ($value) { return $this->localizeMonthName($value); }, $er->recurringMonthsOfYearNamed()));
+		$months = implode(', ', array_map(function($value) { return $this->localizeMonthName($value); }, $er->recurringMonthsOfYearNamed()));
 		// days of month
 		if ($er->recurringPattern() === 'R') {
-			$days = implode(', ', array_map(function ($value) { return $this->localizeRelativePositionName($value); }, $er->recurringRelativePositionNamed())) . ' '
-					. implode(', ', array_map(function ($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
+			$days = implode(', ', array_map(function($value) { return $this->localizeRelativePositionName($value); }, $er->recurringRelativePositionNamed())).' '
+					. implode(', ', array_map(function($value) { return $this->localizeDayName($value); }, $er->recurringDaysOfWeekNamed()));
 		} else {
 			$days = $er->startDateTime()->format('jS');
 		}
 		// time of the day
 		if (!$er->entireDay()) {
 			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' ('.$er->startTimeZone()->getName().')' : '';
+			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']).' ('.$er->endTimeZone()->getName().')';
 		}
 		// conclusion
 		if ($er->recurringConcludes()) {
@@ -575,7 +575,7 @@ 
 			[false, true, false] => $this->l10n->t('Every Year in %1$s on the %2$s between %3$s - %4$s', [$months, $days, $startTime, $endTime]),
 			[false, true, true] => $this->l10n->t('Every Year in %1$s on the %2$s between %3$s - %4$s until %5$s', [$months, $days, $startTime, $endTime, $conclusion]),
 			[true, false, false] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s for the entire day', [$interval, $months, $days]),
-			[true, false, true] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s for the entire day until %4$s', [$interval, $months,  $days, $conclusion]),
+			[true, false, true] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s for the entire day until %4$s', [$interval, $months, $days, $conclusion]),
 			[true, true, false] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s between %4$s - %5$s', [$interval, $months, $days, $startTime, $endTime]),
 			[true, true, true] => $this->l10n->t('Every %1$d Years in %2$s on the %3$s between %4$s - %5$s until %6$s', [$interval, $months, $days, $startTime, $endTime, $conclusion]),
 			default => $this->l10n->t('Could not generate event recurrence statement')
@@ -598,8 +598,8 @@ 
 		// time of the day
 		if (!$er->entireDay()) {
 			$startTime = $this->l10n->l('time', $er->startDateTime(), ['width' => 'short']);
-			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' (' . $er->startTimeZone()->getName() . ')' : '';
-			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']) . ' (' . $er->endTimeZone()->getName() . ')';
+			$startTime .= $er->startTimeZone() != $er->endTimeZone() ? ' ('.$er->startTimeZone()->getName().')' : '';
+			$endTime = $this->l10n->l('time', $er->endDateTime(), ['width' => 'short']).' ('.$er->endTimeZone()->getName().')';
 		}
 		// conclusion
 		$conclusion = $this->l10n->l('date', $er->recurringConcludesOn(), ['width' => 'long']);
@@ -799,21 +799,21 @@ 
 		$strikethrough = "<span style='text-decoration: line-through'>%s</span>";
 
 		$newMeetingWhen = $this->generateWhenString($eventReaderCurrent);
-		$newSummary = htmlspecialchars(isset($vEvent->SUMMARY) && (string)$vEvent->SUMMARY !== '' ? (string)$vEvent->SUMMARY : $this->l10n->t('Untitled event'));
-		$newDescription = htmlspecialchars(isset($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;
-		$newLocation = htmlspecialchars(isset($vEvent->LOCATION) && (string)$vEvent->LOCATION !== '' ? (string)$vEvent->LOCATION : $defaultVal);
+		$newSummary = htmlspecialchars(isset($vEvent->SUMMARY) && (string) $vEvent->SUMMARY !== '' ? (string) $vEvent->SUMMARY : $this->l10n->t('Untitled event'));
+		$newDescription = htmlspecialchars(isset($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;
+		$newLocation = htmlspecialchars(isset($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_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 : '';
+		$data['meeting_url'] = isset($vEvent->URL) ? (string) $vEvent->URL : '';
 		$data['meeting_location_html'] = $newLocationHtml !== '' ? sprintf($strikethrough, $newLocationHtml) : '';
 		$data['meeting_location'] = $newLocation;
 		return $data;
@@ -830,7 +830,7 @@ 
 		$component = $vObject->VEVENT;
 
 		if (isset($component->RRULE)) {
-			$it = new EventIterator($vObject, (string)$component->UID);
+			$it = new EventIterator($vObject, (string) $component->UID);
 			$maxDate = new \DateTime(IMipPlugin::MAX_DATE);
 			if ($it->isInfinite()) {
 				return $maxDate->getTimestamp();
@@ -1232,7 +1232,7 @@ 
 			$interval = $dateInterval->m;
 			$scale = 'month';
 		} elseif ($dateInterval->d >= 7) {
-			$interval = (int)($dateInterval->d / 7);
+			$interval = (int) ($dateInterval->d / 7);
 			$scale = 'week';
 		} elseif ($dateInterval->d > 0) {
 			$interval = $dateInterval->d;

apps/dav/lib/CalDAV/Reminder/NotificationProvider/EmailProvider.php

Indentation +422 added lines, -422 removed lines

@@ -31,426 +31,426 @@
  * @package OCA\DAV\CalDAV\Reminder\NotificationProvider
  */
 class EmailProvider extends AbstractProvider {
-	/** @var string */
-	public const NOTIFICATION_TYPE = 'EMAIL';
-
-	public function __construct(
-		IConfig $config,
-		private IMailer $mailer,
-		LoggerInterface $logger,
-		L10NFactory $l10nFactory,
-		IURLGenerator $urlGenerator,
-		private IEmailValidator $emailValidator,
-	) {
-		parent::__construct($logger, $l10nFactory, $urlGenerator, $config);
-	}
-
-	/**
-	 * 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 = 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->emailValidator->isValid($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 {
-		$template->addBodyListItem(
-			htmlspecialchars($calendarDisplayName),
-			$l10n->t('Calendar:'),
-			$this->getAbsoluteImagePath('actions/info.png'),
-			htmlspecialchars($calendarDisplayName),
-		);
-
-		$template->addBodyListItem($this->generateDateString($l10n, $vevent), $l10n->t('Date:'),
-			$this->getAbsoluteImagePath('places/calendar.png'));
-
-		if (isset($vevent->LOCATION)) {
-			$template->addBodyListItem(
-				htmlspecialchars((string)$vevent->LOCATION),
-				$l10n->t('Where:'),
-				$this->getAbsoluteImagePath('actions/address.png'),
-				htmlspecialchars((string)$vevent->LOCATION),
-			);
-		}
-		if (isset($vevent->DESCRIPTION)) {
-			$template->addBodyListItem(
-				htmlspecialchars((string)$vevent->DESCRIPTION),
-				$l10n->t('Description:'),
-				$this->getAbsoluteImagePath('actions/more.png'),
-				htmlspecialchars((string)$vevent->DESCRIPTION),
-			);
-		}
-	}
-
-	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 (!$this->emailValidator->isValid($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 ($this->emailValidator->isValid($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 (!$this->emailValidator->isValid($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');
-	}
+    /** @var string */
+    public const NOTIFICATION_TYPE = 'EMAIL';
+
+    public function __construct(
+        IConfig $config,
+        private IMailer $mailer,
+        LoggerInterface $logger,
+        L10NFactory $l10nFactory,
+        IURLGenerator $urlGenerator,
+        private IEmailValidator $emailValidator,
+    ) {
+        parent::__construct($logger, $l10nFactory, $urlGenerator, $config);
+    }
+
+    /**
+     * 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 = 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->emailValidator->isValid($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 {
+        $template->addBodyListItem(
+            htmlspecialchars($calendarDisplayName),
+            $l10n->t('Calendar:'),
+            $this->getAbsoluteImagePath('actions/info.png'),
+            htmlspecialchars($calendarDisplayName),
+        );
+
+        $template->addBodyListItem($this->generateDateString($l10n, $vevent), $l10n->t('Date:'),
+            $this->getAbsoluteImagePath('places/calendar.png'));
+
+        if (isset($vevent->LOCATION)) {
+            $template->addBodyListItem(
+                htmlspecialchars((string)$vevent->LOCATION),
+                $l10n->t('Where:'),
+                $this->getAbsoluteImagePath('actions/address.png'),
+                htmlspecialchars((string)$vevent->LOCATION),
+            );
+        }
+        if (isset($vevent->DESCRIPTION)) {
+            $template->addBodyListItem(
+                htmlspecialchars((string)$vevent->DESCRIPTION),
+                $l10n->t('Description:'),
+                $this->getAbsoluteImagePath('actions/more.png'),
+                htmlspecialchars((string)$vevent->DESCRIPTION),
+            );
+        }
+    }
+
+    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 (!$this->emailValidator->isValid($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 ($this->emailValidator->isValid($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 (!$this->emailValidator->isValid($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');
+    }
 }

Spacing +14 added lines, -14 removed lines

@@ -130,7 +130,7 @@ 
 	 * @param VEvent $vevent
 	 */
 	private function addSubjectAndHeading(IEMailTemplate $template, IL10N $l10n, VEvent $vevent):void {
-		$template->setSubject('Notification: ' . $this->getTitleFromVEvent($vevent, $l10n));
+		$template->setSubject('Notification: '.$this->getTitleFromVEvent($vevent, $l10n));
 		$template->addHeading($this->getTitleFromVEvent($vevent, $l10n));
 	}
 
@@ -156,18 +156,18 @@ 
 
 		if (isset($vevent->LOCATION)) {
 			$template->addBodyListItem(
-				htmlspecialchars((string)$vevent->LOCATION),
+				htmlspecialchars((string) $vevent->LOCATION),
 				$l10n->t('Where:'),
 				$this->getAbsoluteImagePath('actions/address.png'),
-				htmlspecialchars((string)$vevent->LOCATION),
+				htmlspecialchars((string) $vevent->LOCATION),
 			);
 		}
 		if (isset($vevent->DESCRIPTION)) {
 			$template->addBodyListItem(
-				htmlspecialchars((string)$vevent->DESCRIPTION),
+				htmlspecialchars((string) $vevent->DESCRIPTION),
 				$l10n->t('Description:'),
 				$this->getAbsoluteImagePath('actions/more.png'),
-				htmlspecialchars((string)$vevent->DESCRIPTION),
+				htmlspecialchars((string) $vevent->DESCRIPTION),
 			);
 		}
 	}
@@ -182,7 +182,7 @@ 
 	 * @param VEvent $vevent
 	 * @return array|null
 	 */
-	private function getOrganizerEMailAndNameFromEvent(VEvent $vevent):?array {
+	private function getOrganizerEMailAndNameFromEvent(VEvent $vevent): ?array {
 		if (!$vevent->ORGANIZER) {
 			return null;
 		}
@@ -405,10 +405,10 @@ 
 			]);
 
 			return $localeStart
-				. ' (' . $startTimezone . ') '
+				. ' ('.$startTimezone.') '
 				. ' - '
 				. $localeEnd
-				. ' (' . $endTimezone . ')';
+				. ' ('.$endTimezone.')';
 		}
 
 		// Show only the time if the day is the same
@@ -422,7 +422,7 @@ 
 		return $localeStart
 			. ' - '
 			. $localeEnd
-			. ' (' . $startTimezone . ')';
+			. ' ('.$startTimezone.')';
 	}
 
 	private function isDayEqual(DateTime $dtStart,
@@ -431,24 +431,24 @@ 
 	}
 
 	private function getWeekDayName(IL10N $l10n, DateTime $dt):string {
-		return (string)$l10n->l('weekdayName', $dt, ['width' => 'abbreviated']);
+		return (string) $l10n->l('weekdayName', $dt, ['width' => 'abbreviated']);
 	}
 
 	private function getDateString(IL10N $l10n, DateTime $dt):string {
-		return (string)$l10n->l('date', $dt, ['width' => 'medium']);
+		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']);
+		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']);
+		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 (string) $vevent->SUMMARY;
 		}
 
 		return $l10n->t('Untitled event');