Merge pull request #35121 from nextcloud/feat/dav-wrap-app-calendars

Feature: Provide access to app generated calendars through CalDAV

12 files changed, 758 insertions, 19 deletions

diff --git a/apps/dav/composer/composer/autoload_classmap.php b/apps/dav/composer/composer/autoload_classmap.php
index a9bf60698fd..6745ffe41b4 100644
--- a/apps/dav/composer/composer/autoload_classmap.php
+++ b/apps/dav/composer/composer/autoload_classmap.php
@@ -37,6 +37,9 @@ return array(
     'OCA\\DAV\\CalDAV\\Activity\\Setting\\Calendar' => $baseDir . '/../lib/CalDAV/Activity/Setting/Calendar.php',
     'OCA\\DAV\\CalDAV\\Activity\\Setting\\Event' => $baseDir . '/../lib/CalDAV/Activity/Setting/Event.php',
     'OCA\\DAV\\CalDAV\\Activity\\Setting\\Todo' => $baseDir . '/../lib/CalDAV/Activity/Setting/Todo.php',
+    'OCA\\DAV\\CalDAV\\AppCalendar\\AppCalendar' => $baseDir . '/../lib/CalDAV/AppCalendar/AppCalendar.php',
+    'OCA\\DAV\\CalDAV\\AppCalendar\\AppCalendarPlugin' => $baseDir . '/../lib/CalDAV/AppCalendar/AppCalendarPlugin.php',
+    'OCA\\DAV\\CalDAV\\AppCalendar\\CalendarObject' => $baseDir . '/../lib/CalDAV/AppCalendar/CalendarObject.php',
     'OCA\\DAV\\CalDAV\\Auth\\CustomPrincipalPlugin' => $baseDir . '/../lib/CalDAV/Auth/CustomPrincipalPlugin.php',
     'OCA\\DAV\\CalDAV\\Auth\\PublicPrincipalPlugin' => $baseDir . '/../lib/CalDAV/Auth/PublicPrincipalPlugin.php',
     'OCA\\DAV\\CalDAV\\BirthdayCalendar\\EnablePlugin' => $baseDir . '/../lib/CalDAV/BirthdayCalendar/EnablePlugin.php',
diff --git a/apps/dav/composer/composer/autoload_static.php b/apps/dav/composer/composer/autoload_static.php
index 48104281cd4..302a424d08e 100644
--- a/apps/dav/composer/composer/autoload_static.php
+++ b/apps/dav/composer/composer/autoload_static.php
@@ -52,6 +52,9 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\CalDAV\\Activity\\Setting\\Calendar' => __DIR__ . '/..' . '/../lib/CalDAV/Activity/Setting/Calendar.php',
         'OCA\\DAV\\CalDAV\\Activity\\Setting\\Event' => __DIR__ . '/..' . '/../lib/CalDAV/Activity/Setting/Event.php',
         'OCA\\DAV\\CalDAV\\Activity\\Setting\\Todo' => __DIR__ . '/..' . '/../lib/CalDAV/Activity/Setting/Todo.php',
+        'OCA\\DAV\\CalDAV\\AppCalendar\\AppCalendar' => __DIR__ . '/..' . '/../lib/CalDAV/AppCalendar/AppCalendar.php',
+        'OCA\\DAV\\CalDAV\\AppCalendar\\AppCalendarPlugin' => __DIR__ . '/..' . '/../lib/CalDAV/AppCalendar/AppCalendarPlugin.php',
+        'OCA\\DAV\\CalDAV\\AppCalendar\\CalendarObject' => __DIR__ . '/..' . '/../lib/CalDAV/AppCalendar/CalendarObject.php',
         'OCA\\DAV\\CalDAV\\Auth\\CustomPrincipalPlugin' => __DIR__ . '/..' . '/../lib/CalDAV/Auth/CustomPrincipalPlugin.php',
         'OCA\\DAV\\CalDAV\\Auth\\PublicPrincipalPlugin' => __DIR__ . '/..' . '/../lib/CalDAV/Auth/PublicPrincipalPlugin.php',
         'OCA\\DAV\\CalDAV\\BirthdayCalendar\\EnablePlugin' => __DIR__ . '/..' . '/../lib/CalDAV/BirthdayCalendar/EnablePlugin.php',
diff --git a/apps/dav/lib/AppInfo/Application.php b/apps/dav/lib/AppInfo/Application.php
index 86749862626..10e1130f907 100644
--- a/apps/dav/lib/AppInfo/Application.php
+++ b/apps/dav/lib/AppInfo/Application.php
@@ -35,6 +35,7 @@ namespace OCA\DAV\AppInfo;
 use Exception;
 use OCA\DAV\BackgroundJob\UpdateCalendarResourcesRoomsBackgroundJob;
 use OCA\DAV\CalDAV\Activity\Backend;
+use OCA\DAV\CalDAV\AppCalendar\AppCalendarPlugin;
 use OCA\DAV\CalDAV\CalendarManager;
 use OCA\DAV\CalDAV\CalendarProvider;
 use OCA\DAV\CalDAV\Reminder\NotificationProvider\AudioProvider;
@@ -44,7 +45,6 @@ use OCA\DAV\CalDAV\Reminder\NotificationProviderManager;
 use OCA\DAV\CalDAV\Reminder\Notifier;
 
 use OCA\DAV\Capabilities;
-use OCA\DAV\CardDAV\CardDavBackend;
 use OCA\DAV\CardDAV\ContactsManager;
 use OCA\DAV\CardDAV\PhotoCache;
 use OCA\DAV\CardDAV\SyncService;
@@ -100,6 +100,7 @@ use OCP\Calendar\IManager as ICalendarManager;
 use OCP\Config\BeforePreferenceDeletedEvent;
 use OCP\Config\BeforePreferenceSetEvent;
 use OCP\Contacts\IManager as IContactsManager;
+use OCP\Files\AppData\IAppDataFactory;
 use OCP\IServerContainer;
 use OCP\IUser;
 use Psr\Container\ContainerInterface;
@@ -119,14 +120,17 @@ class Application extends App implements IBootstrap {
 	public function register(IRegistrationContext $context): void {
 		$context->registerServiceAlias('CardDAVSyncService', SyncService::class);
 		$context->registerService(PhotoCache::class, function (ContainerInterface $c) {
-			/** @var IServerContainer $server */
-			$server = $c->get(IServerContainer::class);
-
 			return new PhotoCache(
-				$server->getAppDataDir('dav-photocache'),
+				$c->get(IAppDataFactory::class)->get('dav-photocache'),
 				$c->get(LoggerInterface::class)
 			);
 		});
+		$context->registerService(AppCalendarPlugin::class, function(ContainerInterface $c) {
+			return new AppCalendarPlugin(
+			  $c->get(ICalendarManager::class),
+			  $c->get(LoggerInterface::class)
+			);
+		  });
 
 		/*
 		 * Register capabilities
diff --git a/apps/dav/lib/AppInfo/PluginManager.php b/apps/dav/lib/AppInfo/PluginManager.php
index 0b83d6a9205..828818455f7 100644
--- a/apps/dav/lib/AppInfo/PluginManager.php
+++ b/apps/dav/lib/AppInfo/PluginManager.php
@@ -29,6 +29,7 @@ declare(strict_types=1);
 namespace OCA\DAV\AppInfo;
 
 use OC\ServerContainer;
+use OCA\DAV\CalDAV\AppCalendar\AppCalendarPlugin;
 use OCA\DAV\CalDAV\Integration\ICalendarProvider;
 use OCA\DAV\CardDAV\Integration\IAddressBookProvider;
 use OCP\App\IAppManager;
@@ -144,6 +145,8 @@ class PluginManager {
 		}
 		$this->populated = true;
 
+		$this->calendarPlugins[] = $this->container->get(AppCalendarPlugin::class);
+
 		foreach ($this->appManager->getInstalledApps() as $app) {
 			// load plugins and collections from info.xml
 			$info = $this->appManager->getAppInfo($app);
@@ -253,7 +256,7 @@ class PluginManager {
 
 	private function createClass(string $className): object {
 		try {
-			return $this->container->query($className);
+			return $this->container->get($className);
 		} catch (QueryException $e) {
 			if (class_exists($className)) {
 				return new $className();
diff --git a/apps/dav/lib/CalDAV/AppCalendar/AppCalendar.php b/apps/dav/lib/CalDAV/AppCalendar/AppCalendar.php
new file mode 100644
index 00000000000..d67f1f5a816
--- /dev/null
+++ b/apps/dav/lib/CalDAV/AppCalendar/AppCalendar.php
@@ -0,0 +1,208 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * @copyright 2023 Ferdinand Thiessen <opensource@fthiessen.de>
+ *
+ * @author Ferdinand Thiessen <opensource@fthiessen.de>
+ *
+ * @license AGPL-3.0-or-later
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\DAV\CalDAV\AppCalendar;
+
+use OCA\DAV\CalDAV\Plugin;
+use OCA\DAV\CalDAV\Integration\ExternalCalendar;
+use OCP\Calendar\ICalendar;
+use OCP\Calendar\ICreateFromString;
+use OCP\Constants;
+use Sabre\CalDAV\CalendarQueryValidator;
+use Sabre\CalDAV\ICalendarObject;
+use Sabre\CalDAV\Xml\Property\SupportedCalendarComponentSet;
+use Sabre\DAV\Exception\Forbidden;
+use Sabre\DAV\Exception\NotFound;
+use Sabre\DAV\PropPatch;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Reader;
+
+class AppCalendar extends ExternalCalendar {
+	protected string $principal;
+	protected ICalendar $calendar;
+
+	public function __construct(string $appId, ICalendar $calendar, string $principal) {
+		parent::__construct($appId, $calendar->getUri());
+		$this->principal = $principal;
+		$this->calendar = $calendar;
+	}
+
+	/**
+	 * Return permissions supported by the backend calendar
+	 * @return int Permissions based on \OCP\Constants
+	 */
+	public function getPermissions(): int {
+		// Make sure to only promote write support if the backend implement the correct interface
+		if ($this->calendar instanceof ICreateFromString) {
+			return $this->calendar->getPermissions();
+		}
+		return Constants::PERMISSION_READ;
+	}
+
+	public function getOwner(): ?string {
+		return $this->principal;
+	}
+
+	public function getGroup(): ?string {
+		return null;
+	}
+
+	public function getACL(): array {
+		$acl = [
+			[
+				'privilege' => '{DAV:}read',
+				'principal' => $this->getOwner(),
+				'protected' => true,
+			],
+			[
+				'privilege' => '{DAV:}write-properties',
+				'principal' => $this->getOwner(),
+				'protected' => true,
+			]
+		];
+		if ($this->getPermissions() & Constants::PERMISSION_CREATE) {
+			$acl[] = [
+				'privilege' => '{DAV:}write',
+				'principal' => $this->getOwner(),
+				'protected' => true,
+			];
+		}
+		return $acl;
+	}
+
+	public function setACL(array $acl): void {
+		throw new Forbidden('Setting ACL is not supported on this node');
+	}
+
+	public function getSupportedPrivilegeSet(): ?array {
+		// Use the default one
+		return null;
+	}
+
+	public function getLastModified(): ?int {
+		// unknown
+		return null;
+	}
+
+	public function delete(): void {
+		// No method for deleting a calendar in OCP\Calendar\ICalendar
+		throw new Forbidden('Deleting an entry is not implemented');
+	}
+
+	public function createFile($name, $data = null) {
+		if ($this->calendar instanceof ICreateFromString) {
+			if (is_resource($data)) {
+				$data = stream_get_contents($data) ?: null;
+			}
+			$this->calendar->createFromString($name, is_null($data) ? '' : $data);
+			return null;
+		} else {
+			throw new Forbidden('Creating a new entry is not allowed');
+		}
+	}
+
+	public function getProperties($properties) {
+		return [
+			'{DAV:}displayname' => $this->calendar->getDisplayName() ?: $this->calendar->getKey(),
+			'{http://apple.com/ns/ical/}calendar-color' => $this->calendar->getDisplayColor() ?: '#0082c9',
+			'{' . Plugin::NS_CALDAV . '}supported-calendar-component-set' => new SupportedCalendarComponentSet(['VEVENT', 'VJOURNAL', 'VTODO']),
+		];
+	}
+
+	public function calendarQuery(array $filters) {
+		$result = [];
+		$objects = $this->getChildren();
+
+		foreach ($objects as $object) {
+			if ($this->validateFilterForObject($object, $filters)) {
+				$result[] = $object->getName();
+			}
+		}
+
+		return $result;
+	}
+
+	protected function validateFilterForObject(ICalendarObject $object, array $filters): bool {
+		/** @var \Sabre\VObject\Component\VCalendar */
+		$vObject = Reader::read($object->get());
+
+		$validator = new CalendarQueryValidator();
+		$result = $validator->validate($vObject, $filters);
+
+		// Destroy circular references so PHP will GC the object.
+		$vObject->destroy();
+
+		return $result;
+	}
+
+	public function childExists($name): bool {
+		try {
+			$this->getChild($name);
+			return true;
+		} catch (NotFound $error) {
+			return false;
+		}
+	}
+
+	public function getChild($name) {
+		// Try to get calendar by filename
+		$children = $this->calendar->search($name, ['X-FILENAME']);
+		if (count($children) === 0) {
+			// If nothing found try to get by UID from filename
+			$pos = strrpos($name, '.ics');
+			$children = $this->calendar->search(substr($name, 0, $pos ?: null), ['UID']);
+		}
+
+		if (count($children) > 0) {
+			return new CalendarObject($this, $this->calendar, new VCalendar($children));
+		}
+
+		throw new NotFound('Node not found');
+	}
+
+	/**
+	 * @return ICalendarObject[]
+	 */
+	public function getChildren(): array {
+		$objects = $this->calendar->search('');
+		// We need to group by UID (actually by filename but we do not have that information)
+		$result = [];
+		foreach ($objects as $object) {
+			$uid = (string)$object['UID'] ?: uniqid();
+			if (!isset($result[$uid])) {
+				$result[$uid] = [];
+			}
+			$result[$uid][] = $object;
+		}
+
+		return array_map(function (array $children) {
+			return new CalendarObject($this, $this->calendar, new VCalendar($children));
+		}, $result);
+	}
+
+	public function propPatch(PropPatch $propPatch): void {
+		// no setDisplayColor or setDisplayName in \OCP\Calendar\ICalendar
+	}
+}
diff --git a/apps/dav/lib/CalDAV/AppCalendar/AppCalendarPlugin.php b/apps/dav/lib/CalDAV/AppCalendar/AppCalendarPlugin.php
new file mode 100644
index 00000000000..cdf7cb9059a
--- /dev/null
+++ b/apps/dav/lib/CalDAV/AppCalendar/AppCalendarPlugin.php
@@ -0,0 +1,74 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * @copyright 2023 Ferdinand Thiessen <opensource@fthiessen.de>
+ *
+ * @author Ferdinand Thiessen <opensource@fthiessen.de>
+ *
+ * @license AGPL-3.0-or-later
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\DAV\CalDAV\AppCalendar;
+
+use OCA\DAV\CalDAV\Integration\ExternalCalendar;
+use OCA\DAV\CalDAV\Integration\ICalendarProvider;
+use OCP\Calendar\IManager;
+use Psr\Log\LoggerInterface;
+
+/* Plugin for wrapping application generated calendars registered in nextcloud core (OCP\Calendar\ICalendarProvider) */
+class AppCalendarPlugin implements ICalendarProvider {
+	protected IManager $manager;
+	protected LoggerInterface $logger;
+
+	public function __construct(IManager $manager, LoggerInterface $logger) {
+		$this->manager = $manager;
+		$this->logger = $logger;
+	}
+
+	public function getAppID(): string {
+		return 'dav-wrapper';
+	}
+
+	public function fetchAllForCalendarHome(string $principalUri): array {
+		return array_map(function ($calendar) use (&$principalUri) {
+			return new AppCalendar($this->getAppID(), $calendar, $principalUri);
+		}, $this->getWrappedCalendars($principalUri));
+	}
+
+	public function hasCalendarInCalendarHome(string $principalUri, string $calendarUri): bool {
+		return count($this->getWrappedCalendars($principalUri, [ $calendarUri ])) > 0;
+	}
+
+	public function getCalendarInCalendarHome(string $principalUri, string $calendarUri): ?ExternalCalendar {
+		$calendars = $this->getWrappedCalendars($principalUri, [ $calendarUri ]);
+		if (count($calendars) > 0) {
+			return new AppCalendar($this->getAppID(), $calendars[0], $principalUri);
+		}
+
+		return null;
+	}
+
+	protected function getWrappedCalendars(string $principalUri, array $calendarUris = []): array {
+		return array_values(
+			array_filter($this->manager->getCalendarsForPrincipal($principalUri, $calendarUris), function ($c) {
+				// We must not provide a wrapper for DAV calendars
+				return ! ($c instanceof \OCA\DAV\CalDAV\CalendarImpl);
+			})
+		);
+	}
+}
diff --git a/apps/dav/lib/CalDAV/AppCalendar/CalendarObject.php b/apps/dav/lib/CalDAV/AppCalendar/CalendarObject.php
new file mode 100644
index 00000000000..985b137c955
--- /dev/null
+++ b/apps/dav/lib/CalDAV/AppCalendar/CalendarObject.php
@@ -0,0 +1,153 @@
+<?php
+declare(strict_types=1);
+
+/**
+ * @copyright 2023 Ferdinand Thiessen <opensource@fthiessen.de>
+ *
+ * @author Ferdinand Thiessen <opensource@fthiessen.de>
+ *
+ * @license AGPL-3.0-or-later
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OCA\DAV\CalDAV\AppCalendar;
+
+use OCP\Calendar\ICalendar;
+use OCP\Calendar\ICreateFromString;
+use OCP\Constants;
+use Sabre\CalDAV\ICalendarObject;
+use Sabre\DAV\Exception\Forbidden;
+use Sabre\DAV\Exception\NotFound;
+use Sabre\DAVACL\IACL;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Property\ICalendar\DateTime;
+
+class CalendarObject implements ICalendarObject, IACL {
+	private VCalendar $vobject;
+	private AppCalendar $calendar;
+	private ICalendar|ICreateFromString $backend;
+
+	public function __construct(AppCalendar $calendar, ICalendar $backend, VCalendar $vobject) {
+		$this->backend = $backend;
+		$this->calendar = $calendar;
+		$this->vobject = $vobject;
+	}
+
+	public function getOwner() {
+		return $this->calendar->getOwner();
+	}
+
+	public function getGroup() {
+		return $this->calendar->getGroup();
+	}
+
+	public function getACL(): array {
+		$acl = [
+			[
+				'privilege' => '{DAV:}read',
+				'principal' => $this->getOwner(),
+				'protected' => true,
+			]
+		];
+		if ($this->calendar->getPermissions() & Constants::PERMISSION_UPDATE) {
+			$acl[] = [
+				'privilege' => '{DAV:}write-content',
+				'principal' => $this->getOwner(),
+				'protected' => true,
+			];
+		}
+		return $acl;
+	}
+
+	public function setACL(array $acl): void {
+		throw new Forbidden('Setting ACL is not supported on this node');
+	}
+
+	public function getSupportedPrivilegeSet(): ?array {
+		return null;
+	}
+
+	public function put($data): void {
+		if ($this->backend instanceof ICreateFromString && $this->calendar->getPermissions() & Constants::PERMISSION_UPDATE) {
+			if (is_resource($data)) {
+				$data = stream_get_contents($data) ?: '';
+			}
+			$this->backend->createFromString($this->getName(), $data);
+		} else {
+			throw new Forbidden('This calendar-object is read-only');
+		}
+	}
+
+	public function get(): string {
+		return $this->vobject->serialize();
+	}
+
+	public function getContentType(): string {
+		return 'text/calendar; charset=utf-8';
+	}
+
+	public function getETag(): ?string {
+		return null;
+	}
+
+	public function getSize() {
+		return mb_strlen($this->vobject->serialize());
+	}
+
+	public function delete(): void {
+		if ($this->backend instanceof ICreateFromString && $this->calendar->getPermissions() & Constants::PERMISSION_DELETE) {
+			/** @var \Sabre\VObject\Component[] */
+			$components = $this->vobject->getBaseComponents();
+			foreach ($components as $key => $component) {
+				$components[$key]->STATUS = 'CANCELLED';
+				$components[$key]->SEQUENCE = isset($component->SEQUENCE) ? ((int)$component->SEQUENCE->getValue()) + 1 : 1;
+				if ($component->name === 'VEVENT') {
+					$components[$key]->METHOD = 'CANCEL';
+				}
+			}
+			$this->backend->createFromString($this->getName(), (new VCalendar($components))->serialize());
+		} else {
+			throw new Forbidden('This calendar-object is read-only');
+		}
+	}
+
+	public function getName(): string {
+		// Every object is required to have an UID
+		$base = $this->vobject->getBaseComponent();
+		// This should never happen except the app provides invalid calendars (VEvent, VTodo... all require UID to be present)
+		if ($base === null) {
+			throw new NotFound('Invalid node');
+		}
+		if (isset($base->{'X-FILENAME'})) {
+			return (string)$base->{'X-FILENAME'};
+		}
+		return (string)$base->UID . '.ics';
+	}
+
+	public function setName($name): void {
+		throw new Forbidden('This calendar-object is read-only');
+	}
+
+	public function getLastModified(): ?int {
+		$base = $this->vobject->getBaseComponent();
+		if ($base !== null && $this->vobject->getBaseComponent()->{'LAST-MODIFIED'}) {
+			/** @var DateTime */
+			$lastModified = $this->vobject->getBaseComponent()->{'LAST-MODIFIED'};
+			return $lastModified->getDateTime()->getTimestamp();
+		}
+		return null;
+	}
+}
diff --git a/apps/dav/lib/CalDAV/CalendarProvider.php b/apps/dav/lib/CalDAV/CalendarProvider.php
index 5779111add3..f29c601db2d 100644
--- a/apps/dav/lib/CalDAV/CalendarProvider.php
+++ b/apps/dav/lib/CalDAV/CalendarProvider.php
@@ -26,7 +26,6 @@ declare(strict_types=1);
 namespace OCA\DAV\CalDAV;
 
 use OCP\Calendar\ICalendarProvider;
-use OCP\Calendar\ICreateFromString;
 use OCP\IConfig;
 use OCP\IL10N;
 use Psr\Log\LoggerInterface;
diff --git a/apps/dav/tests/unit/AppInfo/PluginManagerTest.php b/apps/dav/tests/unit/AppInfo/PluginManagerTest.php
index 17f8ffda625..67dd0477685 100644
--- a/apps/dav/tests/unit/AppInfo/PluginManagerTest.php
+++ b/apps/dav/tests/unit/AppInfo/PluginManagerTest.php
@@ -29,6 +29,7 @@ namespace OCA\DAV\Tests\unit\AppInfo;
 use OC\App\AppManager;
 use OC\ServerContainer;
 use OCA\DAV\AppInfo\PluginManager;
+use OCA\DAV\CalDAV\AppCalendar\AppCalendarPlugin;
 use OCA\DAV\CalDAV\Integration\ICalendarProvider;
 use Sabre\DAV\Collection;
 use Sabre\DAV\ServerPlugin;
@@ -43,7 +44,6 @@ class PluginManagerTest extends TestCase {
 	public function test(): void {
 		$server = $this->createMock(ServerContainer::class);
 
-
 		$appManager = $this->createMock(AppManager::class);
 		$appManager->method('getInstalledApps')
 			->willReturn(['adavapp', 'adavapp2']);
@@ -94,6 +94,7 @@ class PluginManagerTest extends TestCase {
 
 		$pluginManager = new PluginManager($server, $appManager);
 
+		$appCalendarPlugin = $this->createMock(AppCalendarPlugin::class);
 		$calendarPlugin1 = $this->createMock(ICalendarProvider::class);
 		$calendarPlugin2 = $this->createMock(ICalendarProvider::class);
 		$calendarPlugin3 = $this->createMock(ICalendarProvider::class);
@@ -106,17 +107,18 @@ class PluginManagerTest extends TestCase {
 		$dummyCollection2 = $this->createMock(Collection::class);
 		$dummy2Collection1 = $this->createMock(Collection::class);
 
-		$server->method('query')
+		$server->method('get')
 			->willReturnMap([
-				['\OCA\DAV\ADavApp\PluginOne', true, $dummyPlugin1],
-				['\OCA\DAV\ADavApp\PluginTwo', true, $dummyPlugin2],
-				['\OCA\DAV\ADavApp\CalendarPluginOne', true, $calendarPlugin1],
-				['\OCA\DAV\ADavApp\CalendarPluginTwo', true, $calendarPlugin2],
-				['\OCA\DAV\ADavApp\CollectionOne', true, $dummyCollection1],
-				['\OCA\DAV\ADavApp\CollectionTwo', true, $dummyCollection2],
-				['\OCA\DAV\ADavApp2\PluginOne', true, $dummy2Plugin1],
-				['\OCA\DAV\ADavApp2\CalendarPluginOne', true, $calendarPlugin3],
-				['\OCA\DAV\ADavApp2\CollectionOne', true, $dummy2Collection1],
+				[AppCalendarPlugin::class, $appCalendarPlugin],
+				['\OCA\DAV\ADavApp\PluginOne', $dummyPlugin1],
+				['\OCA\DAV\ADavApp\PluginTwo', $dummyPlugin2],
+				['\OCA\DAV\ADavApp\CalendarPluginOne', $calendarPlugin1],
+				['\OCA\DAV\ADavApp\CalendarPluginTwo', $calendarPlugin2],
+				['\OCA\DAV\ADavApp\CollectionOne', $dummyCollection1],
+				['\OCA\DAV\ADavApp\CollectionTwo', $dummyCollection2],
+				['\OCA\DAV\ADavApp2\PluginOne', $dummy2Plugin1],
+				['\OCA\DAV\ADavApp2\CalendarPluginOne', $calendarPlugin3],
+				['\OCA\DAV\ADavApp2\CollectionOne', $dummy2Collection1],
 			]);
 
 		$expectedPlugins = [
@@ -125,6 +127,7 @@ class PluginManagerTest extends TestCase {
 			$dummy2Plugin1,
 		];
 		$expectedCalendarPlugins = [
+			$appCalendarPlugin,
 			$calendarPlugin1,
 			$calendarPlugin2,
 			$calendarPlugin3,
diff --git a/apps/dav/tests/unit/CalDAV/AppCalendar/AppCalendarTest.php b/apps/dav/tests/unit/CalDAV/AppCalendar/AppCalendarTest.php
new file mode 100644
index 00000000000..78ebf8b67a4
--- /dev/null
+++ b/apps/dav/tests/unit/CalDAV/AppCalendar/AppCalendarTest.php
@@ -0,0 +1,123 @@
+<?php
+/**
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+namespace OCA\DAV\Tests\unit\CalDAV\AppCalendar;
+
+use OCA\DAV\CalDAV\AppCalendar\AppCalendar;
+use OCP\Calendar\ICalendar;
+use OCP\Calendar\ICreateFromString;
+use OCP\Constants;
+use PHPUnit\Framework\MockObject\MockObject;
+use Test\TestCase;
+
+use function Safe\rewind;
+
+class AppCalendarTest extends TestCase {
+	private $principal = 'principals/users/foo';
+
+	private AppCalendar $appCalendar;
+	private AppCalendar $writeableAppCalendar;
+
+	private ICalendar|MockObject $calendar;
+	private ICalendar|MockObject $writeableCalendar;
+	
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->calendar = $this->getMockBuilder(ICalendar::class)->getMock();
+		$this->calendar->method('getPermissions')
+			->willReturn(Constants::PERMISSION_READ);
+
+		$this->writeableCalendar = $this->getMockBuilder(ICreateFromString::class)->getMock();
+		$this->writeableCalendar->method('getPermissions')
+			->willReturn(Constants::PERMISSION_READ | Constants::PERMISSION_CREATE);
+
+		$this->appCalendar = new AppCalendar('dav-wrapper', $this->calendar, $this->principal);
+		$this->writeableAppCalendar = new AppCalendar('dav-wrapper', $this->writeableCalendar, $this->principal);
+	}
+
+	public function testGetPrincipal():void {
+		// Check that the correct name is returned
+		$this->assertEquals($this->principal, $this->appCalendar->getOwner());
+		$this->assertEquals($this->principal, $this->writeableAppCalendar->getOwner());
+	}
+
+	public function testDelete(): void {
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+		$this->expectExceptionMessage('Deleting an entry is not implemented');
+
+		$this->appCalendar->delete();
+	}
+
+	public function testCreateFile() {
+		$this->writeableCalendar->expects($this->exactly(3))
+			->method('createFromString')
+			->withConsecutive(['some-name', 'data'], ['other-name', ''], ['name', 'some data']);
+
+		// pass data
+		$this->assertNull($this->writeableAppCalendar->createFile('some-name', 'data'));
+		// null is empty string
+		$this->assertNull($this->writeableAppCalendar->createFile('other-name', null));
+		// resource to data
+		$fp = fopen('php://memory', 'r+');
+		fwrite($fp, 'some data');
+		rewind($fp);
+		$this->assertNull($this->writeableAppCalendar->createFile('name', $fp));
+		fclose($fp);
+	}
+
+	public function testCreateFile_readOnly() {
+		// If writing is not supported
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+		$this->expectExceptionMessage('Creating a new entry is not allowed');
+
+		$this->appCalendar->createFile('some-name', 'data');
+	}
+
+	public function testSetACL(): void {
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+		$this->expectExceptionMessage('Setting ACL is not supported on this node');
+
+		$this->appCalendar->setACL([]);
+	}
+
+	public function testGetACL():void {
+		$expectedRO = [
+			[
+				'privilege' => '{DAV:}read',
+				'principal' => $this->principal,
+				'protected' => true,
+			],
+			[
+				'privilege' => '{DAV:}write-properties',
+				'principal' => $this->principal,
+				'protected' => true,
+			]
+		];
+		$expectedRW = $expectedRO;
+		$expectedRW[] = [
+			'privilege' => '{DAV:}write',
+			'principal' => $this->principal,
+			'protected' => true,
+		];
+		
+		// Check that the correct ACL is returned (default be only readable)
+		$this->assertEquals($expectedRO, $this->appCalendar->getACL());
+		$this->assertEquals($expectedRW, $this->writeableAppCalendar->getACL());
+	}
+}
diff --git a/apps/dav/tests/unit/CalDAV/AppCalendar/CalendarObjectTest.php b/apps/dav/tests/unit/CalDAV/AppCalendar/CalendarObjectTest.php
new file mode 100644
index 00000000000..e7bd2cc0b95
--- /dev/null
+++ b/apps/dav/tests/unit/CalDAV/AppCalendar/CalendarObjectTest.php
@@ -0,0 +1,166 @@
+<?php
+
+namespace OCA\DAV\Tests\unit\CalDAV\AppCalendar;
+
+use OCA\DAV\CalDAV\AppCalendar\AppCalendar;
+use OCA\DAV\CalDAV\AppCalendar\CalendarObject;
+use OCP\Calendar\ICalendar;
+use OCP\Calendar\ICreateFromString;
+use OCP\Constants;
+use PHPUnit\Framework\MockObject\MockObject;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Component\VEvent;
+use Test\TestCase;
+
+class CalendarObjectTest extends TestCase {
+	private CalendarObject $calendarObject;
+	private AppCalendar|MockObject $calendar;
+	private ICalendar|MockObject $backend;
+	private VCalendar|MockObject $vobject;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->calendar = $this->createMock(AppCalendar::class);
+		$this->calendar->method('getOwner')->willReturn('owner');
+		$this->calendar->method('getGroup')->willReturn('group');
+
+		$this->backend = $this->createMock(ICalendar::class);
+		$this->vobject = $this->createMock(VCalendar::class);
+		$this->calendarObject = new CalendarObject($this->calendar, $this->backend, $this->vobject);
+	}
+
+	public function testGetOwner() {
+		$this->assertEquals($this->calendarObject->getOwner(), 'owner');
+	}
+
+	public function testGetGroup() {
+		$this->assertEquals($this->calendarObject->getGroup(), 'group');
+	}
+
+	public function testGetACL() {
+		$this->calendar->expects($this->exactly(2))
+			->method('getPermissions')
+			->willReturnOnConsecutiveCalls(Constants::PERMISSION_READ, Constants::PERMISSION_ALL);
+
+		// read only
+		$this->assertEquals($this->calendarObject->getACL(), [
+			[
+				'privilege' => '{DAV:}read',
+				'principal' => 'owner',
+				'protected' => true,
+			]
+		]);
+
+		// write permissions
+		$this->assertEquals($this->calendarObject->getACL(), [
+			[
+				'privilege' => '{DAV:}read',
+				'principal' => 'owner',
+				'protected' => true,
+			],
+			[
+				'privilege' => '{DAV:}write-content',
+				'principal' => 'owner',
+				'protected' => true,
+			]
+		]);
+	}
+
+	public function testSetACL() {
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+		$this->calendarObject->setACL([]);
+	}
+
+	public function testPut_readOnlyBackend() {
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+		$this->calendarObject->put('foo');
+	}
+
+	public function testPut_noPermissions() {
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+
+		$backend = $this->createMock(ICreateFromString::class);
+		$calendarObject = new CalendarObject($this->calendar, $backend, $this->vobject);
+
+		$this->calendar->expects($this->once())
+			->method('getPermissions')
+			->willReturn(Constants::PERMISSION_READ);
+
+		$calendarObject->put('foo');
+	}
+
+	public function testPut() {
+		$backend = $this->createMock(ICreateFromString::class);
+		$calendarObject = new CalendarObject($this->calendar, $backend, $this->vobject);
+
+		$this->vobject->expects($this->once())
+			->method('getBaseComponent')
+			->willReturn((object)['UID' => 'someid']);
+		$this->calendar->expects($this->once())
+			->method('getPermissions')
+			->willReturn(Constants::PERMISSION_ALL);
+
+		$backend->expects($this->once())
+			->method('createFromString')
+			->with('someid.ics', 'foo');
+		$calendarObject->put('foo');
+	}
+
+	public function testGet() {
+		$this->vobject->expects($this->once())
+			->method('serialize')
+			->willReturn('foo');
+		$this->assertEquals($this->calendarObject->get(), 'foo');
+	}
+
+	public function testDelete_notWriteable() {
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+		$this->calendarObject->delete();
+	}
+
+	public function testDelete_noPermission() {
+		$backend = $this->createMock(ICreateFromString::class);
+		$calendarObject = new CalendarObject($this->calendar, $backend, $this->vobject);
+
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+		$calendarObject->delete();
+	}
+
+	public function testDelete() {
+		$backend = $this->createMock(ICreateFromString::class);
+		$calendarObject = new CalendarObject($this->calendar, $backend, $this->vobject);
+
+		$components = [(new VCalendar(['VEVENT' => ['UID' => 'someid']]))->getBaseComponent()];
+
+		$this->calendar->expects($this->once())
+			->method('getPermissions')
+			->willReturn(Constants::PERMISSION_DELETE);
+		$this->vobject->expects($this->once())
+			->method('getBaseComponents')
+			->willReturn($components);
+		$this->vobject->expects($this->once())
+			->method('getBaseComponent')
+			->willReturn($components[0]);
+
+		$backend->expects($this->once())
+			->method('createFromString')
+			->with('someid.ics', self::callback(fn($data): bool => preg_match('/BEGIN:VEVENT(.|\r\n)+STATUS:CANCELLED/', $data) === 1));
+
+		$calendarObject->delete();
+	}
+
+	public function testGetName() {
+		$this->vobject->expects($this->exactly(2))
+			->method('getBaseComponent')
+			->willReturnOnConsecutiveCalls((object)['UID' => 'someid'], (object)['UID' => 'someid', 'X-FILENAME' => 'real-filename.ics']);
+
+		$this->assertEquals($this->calendarObject->getName(), 'someid.ics');
+		$this->assertEquals($this->calendarObject->getName(), 'real-filename.ics');
+	}
+
+	public function testSetName() {
+		$this->expectException(\Sabre\DAV\Exception\Forbidden::class);
+		$this->calendarObject->setName('Some name');
+	}
+}
diff --git a/apps/dav/tests/unit/Command/DeleteCalendarTest.php b/apps/dav/tests/unit/Command/DeleteCalendarTest.php
index dec349006ff..1c499dbcc25 100644
--- a/apps/dav/tests/unit/Command/DeleteCalendarTest.php
+++ b/apps/dav/tests/unit/Command/DeleteCalendarTest.php
@@ -25,7 +25,7 @@ declare(strict_types=1);
 namespace OCA\DAV\Tests\Command;
 
 use OCA\DAV\CalDAV\BirthdayService;
-use OCA\DAV\CalDav\CalDavBackend;
+use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\Command\DeleteCalendar;
 use OCP\IConfig;
 use OCP\IL10N;