1 files changed, 41 insertions, 0 deletions
diff --git a/apps/dav/lib/CalDAV/DefaultCalendarValidator.php b/apps/dav/lib/CalDAV/DefaultCalendarValidator.php
new file mode 100644
index 00000000000..266e07ef255
--- /dev/null
+++ b/apps/dav/lib/CalDAV/DefaultCalendarValidator.php
@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\DAV\CalDAV;
+
+use Sabre\DAV\Exception as DavException;
+
+class DefaultCalendarValidator {
+	/**
+	 * Check if a given Calendar node is suitable to be used as the default calendar for scheduling.
+	 *
+	 * @throws DavException If the calendar is not suitable to be used as the default calendar
+	 */
+	public function validateScheduleDefaultCalendar(Calendar $calendar): void {
+		// Sanity checks for a calendar that should handle invitations
+		if ($calendar->isSubscription()
+			|| !$calendar->canWrite()
+			|| $calendar->isShared()
+			|| $calendar->isDeleted()) {
+			throw new DavException('Calendar is a subscription, not writable, shared or deleted');
+		}
+
+		// Calendar must support VEVENTs
+		$sCCS = '{urn:ietf:params:xml:ns:caldav}supported-calendar-component-set';
+		$calendarProperties = $calendar->getProperties([$sCCS]);
+		if (isset($calendarProperties[$sCCS])) {
+			$supportedComponents = $calendarProperties[$sCCS]->getValue();
+		} else {
+			$supportedComponents = ['VJOURNAL', 'VTODO', 'VEVENT'];
+		}
+		if (!in_array('VEVENT', $supportedComponents, true)) {
+			throw new DavException('Calendar does not support VEVENT components');
+		}
+	}
+}