fix(dav): Parse sender PARTSTAT in REPLYs

Signed-off-by: Anna Larch <anna@nextcloud.com>

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

@@ -217,10 +217,12 @@ class IMipPlugin extends SabreIMipPlugin {
 
 		$sender = substr($iTipMessage->sender, 7);
 
+		$replyingAttendee = null;
 		switch (strtolower($iTipMessage->method)) {
 			case self::METHOD_REPLY:
 				$method = self::METHOD_REPLY;
 				$data = $this->imipService->buildBodyData($vEvent, $oldVevent);
+				$replyingAttendee = $this->imipService->getReplyingAttendee($iTipMessage);
 				break;
 			case self::METHOD_CANCEL:
 				$method = self::METHOD_CANCEL;
@@ -256,7 +258,7 @@ class IMipPlugin extends SabreIMipPlugin {
 		$template = $this->mailer->createEMailTemplate('dav.calendarInvite.' . $method, $data);
 		$template->addHeader();
 
-		$this->imipService->addSubjectAndHeading($template, $method, $data['invitee_name'], $data['meeting_title'], $isModified);
+		$this->imipService->addSubjectAndHeading($template, $method, $data['invitee_name'], $data['meeting_title'], $isModified, $replyingAttendee);
 		$this->imipService->addBulletList($template, $vEvent, $data);
 
 		// Only add response buttons to invitation requests: Fix Issue #11230

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

@@ -366,7 +366,7 @@ class IMipService {
 	 * @param bool $isModified
 	 */
 	public function addSubjectAndHeading(IEMailTemplate $template,
-		string $method, string $sender, string $summary, bool $isModified): void {
+		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]));
@@ -374,7 +374,24 @@ class IMipService {
 		} 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]));
-			$template->addHeading($this->l10n->t('%1$s has responded to your invitation', [$sender]));
+			// 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]));
@@ -603,4 +620,17 @@ class IMipService {
 
 		$template->addBodyText($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;
+	}
 }