Merge pull request #22020 from nextcloud/feature/20918/calendar_search

Add Event and Task Backends for Unified Search

14 files changed, 1834 insertions, 13 deletions

diff --git a/apps/dav/composer/composer/autoload_classmap.php b/apps/dav/composer/composer/autoload_classmap.php
index bd63dee13b7..081f334a4f9 100644
--- a/apps/dav/composer/composer/autoload_classmap.php
+++ b/apps/dav/composer/composer/autoload_classmap.php
@@ -210,8 +210,13 @@ return array(
     'OCA\\DAV\\Provisioning\\Apple\\AppleProvisioningNode' => $baseDir . '/../lib/Provisioning/Apple/AppleProvisioningNode.php',
     'OCA\\DAV\\Provisioning\\Apple\\AppleProvisioningPlugin' => $baseDir . '/../lib/Provisioning/Apple/AppleProvisioningPlugin.php',
     'OCA\\DAV\\RootCollection' => $baseDir . '/../lib/RootCollection.php',
+    'OCA\\DAV\\Search\\ACalendarSearchProvider' => $baseDir . '/../lib/Search/ACalendarSearchProvider.php',
     'OCA\\DAV\\Search\\ContactsSearchProvider' => $baseDir . '/../lib/Search/ContactsSearchProvider.php',
     'OCA\\DAV\\Search\\ContactsSearchResultEntry' => $baseDir . '/../lib/Search/ContactsSearchResultEntry.php',
+    'OCA\\DAV\\Search\\EventsSearchProvider' => $baseDir . '/../lib/Search/EventsSearchProvider.php',
+    'OCA\\DAV\\Search\\EventsSearchResultEntry' => $baseDir . '/../lib/Search/EventsSearchResultEntry.php',
+    'OCA\\DAV\\Search\\TasksSearchProvider' => $baseDir . '/../lib/Search/TasksSearchProvider.php',
+    'OCA\\DAV\\Search\\TasksSearchResultEntry' => $baseDir . '/../lib/Search/TasksSearchResultEntry.php',
     'OCA\\DAV\\Server' => $baseDir . '/../lib/Server.php',
     'OCA\\DAV\\Settings\\CalDAVSettings' => $baseDir . '/../lib/Settings/CalDAVSettings.php',
     'OCA\\DAV\\Storage\\PublicOwnerWrapper' => $baseDir . '/../lib/Storage/PublicOwnerWrapper.php',
diff --git a/apps/dav/composer/composer/autoload_static.php b/apps/dav/composer/composer/autoload_static.php
index a664c86f5fd..3bfdb3b8628 100644
--- a/apps/dav/composer/composer/autoload_static.php
+++ b/apps/dav/composer/composer/autoload_static.php
@@ -225,8 +225,13 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\Provisioning\\Apple\\AppleProvisioningNode' => __DIR__ . '/..' . '/../lib/Provisioning/Apple/AppleProvisioningNode.php',
         'OCA\\DAV\\Provisioning\\Apple\\AppleProvisioningPlugin' => __DIR__ . '/..' . '/../lib/Provisioning/Apple/AppleProvisioningPlugin.php',
         'OCA\\DAV\\RootCollection' => __DIR__ . '/..' . '/../lib/RootCollection.php',
+        'OCA\\DAV\\Search\\ACalendarSearchProvider' => __DIR__ . '/..' . '/../lib/Search/ACalendarSearchProvider.php',
         'OCA\\DAV\\Search\\ContactsSearchProvider' => __DIR__ . '/..' . '/../lib/Search/ContactsSearchProvider.php',
         'OCA\\DAV\\Search\\ContactsSearchResultEntry' => __DIR__ . '/..' . '/../lib/Search/ContactsSearchResultEntry.php',
+        'OCA\\DAV\\Search\\EventsSearchProvider' => __DIR__ . '/..' . '/../lib/Search/EventsSearchProvider.php',
+        'OCA\\DAV\\Search\\EventsSearchResultEntry' => __DIR__ . '/..' . '/../lib/Search/EventsSearchResultEntry.php',
+        'OCA\\DAV\\Search\\TasksSearchProvider' => __DIR__ . '/..' . '/../lib/Search/TasksSearchProvider.php',
+        'OCA\\DAV\\Search\\TasksSearchResultEntry' => __DIR__ . '/..' . '/../lib/Search/TasksSearchResultEntry.php',
         'OCA\\DAV\\Server' => __DIR__ . '/..' . '/../lib/Server.php',
         'OCA\\DAV\\Settings\\CalDAVSettings' => __DIR__ . '/..' . '/../lib/Settings/CalDAVSettings.php',
         'OCA\\DAV\\Storage\\PublicOwnerWrapper' => __DIR__ . '/..' . '/../lib/Storage/PublicOwnerWrapper.php',
diff --git a/apps/dav/lib/AppInfo/Application.php b/apps/dav/lib/AppInfo/Application.php
index 6f2f7b29153..1bad3cb1eba 100644
--- a/apps/dav/lib/AppInfo/Application.php
+++ b/apps/dav/lib/AppInfo/Application.php
@@ -55,6 +55,8 @@ use OCA\DAV\CardDAV\PhotoCache;
 use OCA\DAV\CardDAV\SyncService;
 use OCA\DAV\HookManager;
 use OCA\DAV\Search\ContactsSearchProvider;
+use OCA\DAV\Search\EventsSearchProvider;
+use OCA\DAV\Search\TasksSearchProvider;
 use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
@@ -102,6 +104,8 @@ class Application extends App implements IBootstrap {
 		 * Register Search Providers
 		 */
 		$context->registerSearchProvider(ContactsSearchProvider::class);
+		$context->registerSearchProvider(EventsSearchProvider::class);
+		$context->registerSearchProvider(TasksSearchProvider::class);
 	}
 
 	public function boot(IBootContext $context): void {
diff --git a/apps/dav/lib/CalDAV/CalDavBackend.php b/apps/dav/lib/CalDAV/CalDavBackend.php
index ddfb0a641e5..5cddf6e84b6 100644
--- a/apps/dav/lib/CalDAV/CalDavBackend.php
+++ b/apps/dav/lib/CalDAV/CalDavBackend.php
@@ -1670,6 +1670,124 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 	}
 
 	/**
+	 * @param string $principalUri
+	 * @param string $pattern
+	 * @param array $componentTypes
+	 * @param array $searchProperties
+	 * @param array $searchParameters
+	 * @param array $options
+	 * @return array
+	 */
+	public function searchPrincipalUri(string $principalUri,
+									   string $pattern,
+									   array $componentTypes,
+									   array $searchProperties,
+									   array $searchParameters,
+									   array $options = []): array {
+		$escapePattern = !\array_key_exists('escape_like_param', $options) || $options['escape_like_param'] !== false;
+
+		$calendarObjectIdQuery = $this->db->getQueryBuilder();
+		$calendarOr = $calendarObjectIdQuery->expr()->orX();
+		$searchOr = $calendarObjectIdQuery->expr()->orX();
+
+		// Fetch calendars and subscription
+		$calendars = $this->getCalendarsForUser($principalUri);
+		$subscriptions = $this->getSubscriptionsForUser($principalUri);
+		foreach ($calendars as $calendar) {
+			$calendarAnd = $calendarObjectIdQuery->expr()->andX();
+			$calendarAnd->add($calendarObjectIdQuery->expr()->eq('cob.calendarid', $calendarObjectIdQuery->createNamedParameter((int)$calendar['id'])));
+			$calendarAnd->add($calendarObjectIdQuery->expr()->eq('cob.calendartype', $calendarObjectIdQuery->createNamedParameter(self::CALENDAR_TYPE_CALENDAR)));
+
+			// If it's shared, limit search to public events
+			if ($calendar['principaluri'] !== $calendar['{http://owncloud.org/ns}owner-principal']) {
+				$calendarAnd->add($calendarObjectIdQuery->expr()->eq('co.classification', $calendarObjectIdQuery->createNamedParameter(self::CLASSIFICATION_PUBLIC)));
+			}
+
+			$calendarOr->add($calendarAnd);
+		}
+		foreach ($subscriptions as $subscription) {
+			$subscriptionAnd = $calendarObjectIdQuery->expr()->andX();
+			$subscriptionAnd->add($calendarObjectIdQuery->expr()->eq('cob.calendarid', $calendarObjectIdQuery->createNamedParameter((int)$subscription['id'])));
+			$subscriptionAnd->add($calendarObjectIdQuery->expr()->eq('cob.calendartype', $calendarObjectIdQuery->createNamedParameter(self::CALENDAR_TYPE_SUBSCRIPTION)));
+
+			// If it's shared, limit search to public events
+			if ($subscription['principaluri'] !== $subscription['{http://owncloud.org/ns}owner-principal']) {
+				$subscriptionAnd->add($calendarObjectIdQuery->expr()->eq('co.classification', $calendarObjectIdQuery->createNamedParameter(self::CLASSIFICATION_PUBLIC)));
+			}
+
+			$calendarOr->add($subscriptionAnd);
+		}
+
+		foreach ($searchProperties as $property) {
+			$propertyAnd = $calendarObjectIdQuery->expr()->andX();
+			$propertyAnd->add($calendarObjectIdQuery->expr()->eq('cob.name', $calendarObjectIdQuery->createNamedParameter($property, IQueryBuilder::PARAM_STR)));
+			$propertyAnd->add($calendarObjectIdQuery->expr()->isNull('cob.parameter'));
+
+			$searchOr->add($propertyAnd);
+		}
+		foreach ($searchParameters as $property => $parameter) {
+			$parameterAnd = $calendarObjectIdQuery->expr()->andX();
+			$parameterAnd->add($calendarObjectIdQuery->expr()->eq('cob.name', $calendarObjectIdQuery->createNamedParameter($property, IQueryBuilder::PARAM_STR)));
+			$parameterAnd->add($calendarObjectIdQuery->expr()->eq('cob.parameter', $calendarObjectIdQuery->createNamedParameter($parameter, IQueryBuilder::PARAM_STR)));
+
+			$searchOr->add($parameterAnd);
+		}
+
+		if ($calendarOr->count() === 0) {
+			return [];
+		}
+		if ($searchOr->count() === 0) {
+			return [];
+		}
+
+		$calendarObjectIdQuery->selectDistinct('cob.objectid')
+			->from($this->dbObjectPropertiesTable, 'cob')
+			->leftJoin('cob', 'calendarobjects', 'co', $calendarObjectIdQuery->expr()->eq('co.id', 'cob.objectid'))
+			->andWhere($calendarObjectIdQuery->expr()->in('co.componenttype', $calendarObjectIdQuery->createNamedParameter($componentTypes, IQueryBuilder::PARAM_STR_ARRAY)))
+			->andWhere($calendarOr)
+			->andWhere($searchOr);
+
+		if ('' !== $pattern) {
+			if (!$escapePattern) {
+				$calendarObjectIdQuery->andWhere($calendarObjectIdQuery->expr()->ilike('cob.value', $calendarObjectIdQuery->createNamedParameter($pattern)));
+			} else {
+				$calendarObjectIdQuery->andWhere($calendarObjectIdQuery->expr()->ilike('cob.value', $calendarObjectIdQuery->createNamedParameter('%' . $this->db->escapeLikeParameter($pattern) . '%')));
+			}
+		}
+
+		if (isset($options['limit'])) {
+			$calendarObjectIdQuery->setMaxResults($options['limit']);
+		}
+		if (isset($options['offset'])) {
+			$calendarObjectIdQuery->setFirstResult($options['offset']);
+		}
+
+		$result = $calendarObjectIdQuery->execute();
+		$matches = $result->fetchAll();
+		$result->closeCursor();
+		$matches = array_map(static function (array $match):int {
+			return (int) $match['objectid'];
+		}, $matches);
+
+		$query = $this->db->getQueryBuilder();
+		$query->select('calendardata', 'uri', 'calendarid', 'calendartype')
+			->from('calendarobjects')
+			->where($query->expr()->in('id', $query->createNamedParameter($matches, IQueryBuilder::PARAM_INT_ARRAY)));
+
+		$result = $query->execute();
+		$calendarObjects = $result->fetchAll();
+		$result->closeCursor();
+
+		return array_map(function (array $array): array {
+			$array['calendarid'] = (int)$array['calendarid'];
+			$array['calendartype'] = (int)$array['calendartype'];
+			$array['calendardata'] = $this->readBlob($array['calendardata']);
+
+			return $array;
+		}, $calendarObjects);
+	}
+
+	/**
 	 * Searches through all of a users calendars and calendar objects to find
 	 * an object with a specific UID.
 	 *
diff --git a/apps/dav/lib/Search/ACalendarSearchProvider.php b/apps/dav/lib/Search/ACalendarSearchProvider.php
new file mode 100644
index 00000000000..56273fe17e4
--- /dev/null
+++ b/apps/dav/lib/Search/ACalendarSearchProvider.php
@@ -0,0 +1,138 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\DAV\Search;
+
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCP\App\IAppManager;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\Search\IProvider;
+use Sabre\VObject\Component;
+use Sabre\VObject\Reader;
+
+/**
+ * Class ACalendarSearchProvider
+ *
+ * @package OCA\DAV\Search
+ */
+abstract class ACalendarSearchProvider implements IProvider {
+
+	/** @var IAppManager */
+	protected $appManager;
+
+	/** @var IL10N */
+	protected $l10n;
+
+	/** @var IURLGenerator */
+	protected $urlGenerator;
+
+	/** @var CalDavBackend */
+	protected $backend;
+
+	/**
+	 * ACalendarSearchProvider constructor.
+	 *
+	 * @param IAppManager $appManager
+	 * @param IL10N $l10n
+	 * @param IURLGenerator $urlGenerator
+	 * @param CalDavBackend $backend
+	 */
+	public function __construct(IAppManager $appManager,
+								IL10N $l10n,
+								IURLGenerator $urlGenerator,
+								CalDavBackend $backend) {
+		$this->appManager = $appManager;
+		$this->l10n = $l10n;
+		$this->urlGenerator = $urlGenerator;
+		$this->backend = $backend;
+	}
+
+	/**
+	 * Get an associative array of calendars
+	 * calendarId => calendar
+	 *
+	 * @param string $principalUri
+	 * @return array
+	 */
+	protected function getSortedCalendars(string $principalUri): array {
+		$calendars = $this->backend->getCalendarsForUser($principalUri);
+		$calendarsById = [];
+		foreach ($calendars as $calendar) {
+			$calendarsById[(int) $calendar['id']] = $calendar;
+		}
+
+		return $calendarsById;
+	}
+
+	/**
+	 * Get an associative array of subscriptions
+	 * subscriptionId => subscription
+	 *
+	 * @param string $principalUri
+	 * @return array
+	 */
+	protected function getSortedSubscriptions(string $principalUri): array {
+		$subscriptions = $this->backend->getSubscriptionsForUser($principalUri);
+		$subscriptionsById = [];
+		foreach ($subscriptions as $subscription) {
+			$subscriptionsById[(int) $subscription['id']] = $subscription;
+		}
+
+		return $subscriptionsById;
+	}
+
+	/**
+	 * Returns the primary VEvent / VJournal / VTodo component
+	 * If it's a component with recurrence-ids, it will return
+	 * the primary component
+	 *
+	 * TODO: It would be a nice enhancement to show recurrence-exceptions
+	 * as individual search-results.
+	 * For now we will just display the primary element of a recurrence-set.
+	 *
+	 * @param string $calendarData
+	 * @param string $componentName
+	 * @return Component
+	 */
+	protected function getPrimaryComponent(string $calendarData, string $componentName): Component {
+		$vCalendar = Reader::read($calendarData, Reader::OPTION_FORGIVING);
+
+		$components = $vCalendar->select($componentName);
+		if (count($components) === 1) {
+			return $components[0];
+		}
+
+		// If it's a recurrence-set, take the primary element
+		foreach ($components as $component) {
+			/** @var Component $component */
+			if (!$component->{'RECURRENCE-ID'}) {
+				return $component;
+			}
+		}
+
+		// In case of error, just fallback to the first element in the set
+		return $components[0];
+	}
+}
diff --git a/apps/dav/lib/Search/EventsSearchProvider.php b/apps/dav/lib/Search/EventsSearchProvider.php
new file mode 100644
index 00000000000..43fc4f65dfc
--- /dev/null
+++ b/apps/dav/lib/Search/EventsSearchProvider.php
@@ -0,0 +1,231 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\DAV\Search;
+
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCP\IUser;
+use OCP\Search\ISearchQuery;
+use OCP\Search\SearchResult;
+use Sabre\VObject\Component;
+use Sabre\VObject\DateTimeParser;
+use Sabre\VObject\Property;
+
+/**
+ * Class EventsSearchProvider
+ *
+ * @package OCA\DAV\Search
+ */
+class EventsSearchProvider extends ACalendarSearchProvider {
+
+	/**
+	 * @var string[]
+	 */
+	private static $searchProperties = [
+		'SUMMARY',
+		'LOCATION',
+		'DESCRIPTION',
+		'ATTENDEE',
+		'ORGANIZER',
+		'CATEGORIES',
+	];
+
+	/**
+	 * @var string[]
+	 */
+	private static $searchParameters = [
+		'ATTENDEE' => ['CN'],
+		'ORGANIZER' => ['CN'],
+	];
+
+	/**
+	 * @var string
+	 */
+	private static $componentType = 'VEVENT';
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getId(): string {
+		return 'calendar-dav';
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getName(): string {
+		return $this->l10n->t('Events');
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function search(IUser $user,
+						   ISearchQuery $query): SearchResult {
+		if (!$this->appManager->isEnabledForUser('calendar', $user)) {
+			return SearchResult::complete($this->getName(), []);
+		}
+
+		$principalUri = 'principals/users/' . $user->getUID();
+		$calendarsById = $this->getSortedCalendars($principalUri);
+		$subscriptionsById = $this->getSortedSubscriptions($principalUri);
+
+		$searchResults = $this->backend->searchPrincipalUri(
+			$principalUri,
+			$query->getTerm(),
+			[self::$componentType],
+			self::$searchProperties,
+			self::$searchParameters,
+			[
+				'limit' => $query->getLimit(),
+				'offset' => $query->getCursor(),
+			]
+		);
+		$formattedResults = \array_map(function (array $eventRow) use ($calendarsById, $subscriptionsById):EventsSearchResultEntry {
+			$component = $this->getPrimaryComponent($eventRow['calendardata'], self::$componentType);
+			$title = (string)($component->SUMMARY ?? $this->l10n->t('Untitled event'));
+			$subline = $this->generateSubline($component);
+
+			if ($eventRow['calendartype'] === CalDavBackend::CALENDAR_TYPE_CALENDAR) {
+				$calendar = $calendarsById[$eventRow['calendarid']];
+			} else {
+				$calendar = $subscriptionsById[$eventRow['calendarid']];
+			}
+			$resourceUrl = $this->getDeepLinkToCalendarApp($calendar['principaluri'], $calendar['uri'], $eventRow['uri']);
+
+			return new EventsSearchResultEntry('', $title, $subline, $resourceUrl, 'icon-calendar-dark', false);
+		}, $searchResults);
+
+		return SearchResult::paginated(
+			$this->getName(),
+			$formattedResults,
+			$query->getCursor() + count($formattedResults)
+		);
+	}
+
+	/**
+	 * @param string $principalUri
+	 * @param string $calendarUri
+	 * @param string $calendarObjectUri
+	 * @return string
+	 */
+	protected function getDeepLinkToCalendarApp(string $principalUri,
+												string $calendarUri,
+												string $calendarObjectUri): string {
+		$davUrl = $this->getDavUrlForCalendarObject($principalUri, $calendarUri, $calendarObjectUri);
+		// This route will automatically figure out what recurrence-id to open
+		return $this->urlGenerator->getAbsoluteURL(
+			$this->urlGenerator->linkToRoute('calendar.view.index')
+			. 'edit/'
+			. base64_encode($davUrl)
+		);
+	}
+
+	/**
+	 * @param string $principalUri
+	 * @param string $calendarUri
+	 * @param string $calendarObjectUri
+	 * @return string
+	 */
+	protected function getDavUrlForCalendarObject(string $principalUri,
+												  string $calendarUri,
+												  string $calendarObjectUri): string {
+		[,, $principalId] = explode('/', $principalUri, 3);
+
+		return $this->urlGenerator->linkTo('', 'remote.php') . '/dav/calendars/'
+			. $principalId . '/'
+			. $calendarUri . '/'
+			. $calendarObjectUri;
+	}
+
+	/**
+	 * @param Component $eventComponent
+	 * @return string
+	 */
+	protected function generateSubline(Component $eventComponent): string {
+		$dtStart = $eventComponent->DTSTART;
+		$dtEnd = $this->getDTEndForEvent($eventComponent);
+		$isAllDayEvent = $dtStart instanceof Property\ICalendar\Date;
+		$startDateTime = new \DateTime($dtStart->getDateTime()->format(\DateTime::ATOM));
+		$endDateTime = new \DateTime($dtEnd->getDateTime()->format(\DateTime::ATOM));
+
+		if ($isAllDayEvent) {
+			$endDateTime->modify('-1 day');
+			if ($this->isDayEqual($startDateTime, $endDateTime)) {
+				return $this->l10n->l('date', $startDateTime, ['width' => 'medium']);
+			}
+
+			$formattedStart = $this->l10n->l('date', $startDateTime, ['width' => 'medium']);
+			$formattedEnd = $this->l10n->l('date', $endDateTime, ['width' => 'medium']);
+			return "$formattedStart - $formattedEnd";
+		}
+
+		$formattedStartDate = $this->l10n->l('date', $startDateTime, ['width' => 'medium']);
+		$formattedEndDate = $this->l10n->l('date', $endDateTime, ['width' => 'medium']);
+		$formattedStartTime = $this->l10n->l('time', $startDateTime, ['width' => 'short']);
+		$formattedEndTime = $this->l10n->l('time', $endDateTime, ['width' => 'short']);
+
+		if ($this->isDayEqual($startDateTime, $endDateTime)) {
+			return "$formattedStartDate $formattedStartTime - $formattedEndTime";
+		}
+
+		return "$formattedStartDate $formattedStartTime - $formattedEndDate $formattedEndTime";
+	}
+
+	/**
+	 * @param Component $eventComponent
+	 * @return Property
+	 */
+	protected function getDTEndForEvent(Component $eventComponent):Property {
+		if (isset($eventComponent->DTEND)) {
+			$end = $eventComponent->DTEND;
+		} elseif (isset($eventComponent->DURATION)) {
+			$isFloating = $eventComponent->DTSTART->isFloating();
+			$end = clone $eventComponent->DTSTART;
+			$endDateTime = $end->getDateTime();
+			$endDateTime = $endDateTime->add(DateTimeParser::parse($eventComponent->DURATION->getValue()));
+			$end->setDateTime($endDateTime, $isFloating);
+		} elseif (!$eventComponent->DTSTART->hasTime()) {
+			$isFloating = $eventComponent->DTSTART->isFloating();
+			$end = clone $eventComponent->DTSTART;
+			$endDateTime = $end->getDateTime();
+			$endDateTime = $endDateTime->modify('+1 day');
+			$end->setDateTime($endDateTime, $isFloating);
+		} else {
+			$end = clone $eventComponent->DTSTART;
+		}
+
+		return $end;
+	}
+
+	/**
+	 * @param \DateTime $dtStart
+	 * @param \DateTime $dtEnd
+	 * @return bool
+	 */
+	protected function isDayEqual(\DateTime $dtStart,
+								  \DateTime $dtEnd) {
+		return $dtStart->format('Y-m-d') === $dtEnd->format('Y-m-d');
+	}
+}
diff --git a/apps/dav/lib/Search/EventsSearchResultEntry.php b/apps/dav/lib/Search/EventsSearchResultEntry.php
new file mode 100644
index 00000000000..f70f10a6e75
--- /dev/null
+++ b/apps/dav/lib/Search/EventsSearchResultEntry.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\DAV\Search;
+
+use OCP\Search\ASearchResultEntry;
+
+class EventsSearchResultEntry extends ASearchResultEntry {
+}
diff --git a/apps/dav/lib/Search/TasksSearchProvider.php b/apps/dav/lib/Search/TasksSearchProvider.php
new file mode 100644
index 00000000000..eee4694f08f
--- /dev/null
+++ b/apps/dav/lib/Search/TasksSearchProvider.php
@@ -0,0 +1,160 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\DAV\Search;
+
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCP\IUser;
+use OCP\Search\ISearchQuery;
+use OCP\Search\SearchResult;
+use Sabre\VObject\Component;
+
+/**
+ * Class TasksSearchProvider
+ *
+ * @package OCA\DAV\Search
+ */
+class TasksSearchProvider extends ACalendarSearchProvider {
+
+	/**
+	 * @var string[]
+	 */
+	private static $searchProperties = [
+		'SUMMARY',
+		'DESCRIPTION',
+		'CATEGORIES',
+	];
+
+	/**
+	 * @var string[]
+	 */
+	private static $searchParameters = [];
+
+	/**
+	 * @var string
+	 */
+	private static $componentType = 'VTODO';
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getId(): string {
+		return 'tasks-dav';
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function getName(): string {
+		return $this->l10n->t('Tasks');
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function search(IUser $user,
+						   ISearchQuery $query): SearchResult {
+		if (!$this->appManager->isEnabledForUser('tasks', $user)) {
+			return SearchResult::complete($this->getName(), []);
+		}
+
+		$principalUri = 'principals/users/' . $user->getUID();
+		$calendarsById = $this->getSortedCalendars($principalUri);
+		$subscriptionsById = $this->getSortedSubscriptions($principalUri);
+
+		$searchResults = $this->backend->searchPrincipalUri(
+			$principalUri,
+			$query->getTerm(),
+			[self::$componentType],
+			self::$searchProperties,
+			self::$searchParameters,
+			[
+				'limit' => $query->getLimit(),
+				'offset' => $query->getCursor(),
+			]
+		);
+		$formattedResults = \array_map(function (array $taskRow) use ($calendarsById, $subscriptionsById):TasksSearchResultEntry {
+			$component = $this->getPrimaryComponent($taskRow['calendardata'], self::$componentType);
+			$title = (string)($component->SUMMARY ?? $this->l10n->t('Untitled task'));
+			$subline = $this->generateSubline($component);
+
+			if ($taskRow['calendartype'] === CalDavBackend::CALENDAR_TYPE_CALENDAR) {
+				$calendar = $calendarsById[$taskRow['calendarid']];
+			} else {
+				$calendar = $subscriptionsById[$taskRow['calendarid']];
+			}
+			$resourceUrl = $this->getDeepLinkToTasksApp($calendar['uri'], $taskRow['uri']);
+
+			return new TasksSearchResultEntry('', $title, $subline, $resourceUrl, 'icon-checkmark', false);
+		}, $searchResults);
+
+		return SearchResult::paginated(
+			$this->getName(),
+			$formattedResults,
+			$query->getCursor() + count($formattedResults)
+		);
+	}
+
+	/**
+	 * @param string $calendarUri
+	 * @param string $taskUri
+	 * @return string
+	 */
+	protected function getDeepLinkToTasksApp(string $calendarUri,
+											 string $taskUri): string {
+		return $this->urlGenerator->getAbsoluteURL(
+			$this->urlGenerator->linkToRoute('tasks.page.index')
+			. '#/calendars/'
+			. $calendarUri
+			. '/tasks/'
+			. $taskUri
+		);
+	}
+
+	/**
+	 * @param Component $taskComponent
+	 * @return string
+	 */
+	protected function generateSubline(Component $taskComponent): string {
+		if ($taskComponent->COMPLETED) {
+			$completedDateTime = new \DateTime($taskComponent->COMPLETED->getDateTime()->format(\DateTime::ATOM));
+			$formattedDate = $this->l10n->l('date', $completedDateTime, ['width' => 'medium']);
+			return $this->l10n->t('Completed on %s', [$formattedDate]);
+		}
+
+		if ($taskComponent->DUE) {
+			$dueDateTime = new \DateTime($taskComponent->DUE->getDateTime()->format(\DateTime::ATOM));
+			$formattedDate = $this->l10n->l('date', $dueDateTime, ['width' => 'medium']);
+
+			if ($taskComponent->DUE->hasTime()) {
+				$formattedTime =  $this->l10n->l('time', $dueDateTime, ['width' => 'short']);
+				return $this->l10n->t('Due on %s by %s', [$formattedDate, $formattedTime]);
+			}
+
+			return $this->l10n->t('Due on %s', [$formattedDate]);
+		}
+
+		return '';
+	}
+}
diff --git a/apps/dav/lib/Search/TasksSearchResultEntry.php b/apps/dav/lib/Search/TasksSearchResultEntry.php
new file mode 100644
index 00000000000..ec58ba80af9
--- /dev/null
+++ b/apps/dav/lib/Search/TasksSearchResultEntry.php
@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\DAV\Search;
+
+use OCP\Search\ASearchResultEntry;
+
+class TasksSearchResultEntry extends ASearchResultEntry {
+}
diff --git a/apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php b/apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php
index 4c6c8549055..79da92148af 100644
--- a/apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php
+++ b/apps/dav/tests/unit/CalDAV/AbstractCalDavBackend.php
@@ -121,7 +121,12 @@ abstract class AbstractCalDavBackend extends TestCase {
 		$this->principal->expects($this->any())->method('getGroupMembership')
 			->withAnyParameters()
 			->willReturn([self::UNIT_TEST_GROUP, self::UNIT_TEST_GROUP2]);
-		$calendars = $this->backend->getCalendarsForUser(self::UNIT_TEST_USER);
+		$this->cleanupForPrincipal(self::UNIT_TEST_USER);
+		$this->cleanupForPrincipal(self::UNIT_TEST_USER1);
+	}
+
+	private function cleanupForPrincipal($principal): void {
+		$calendars = $this->backend->getCalendarsForUser($principal);
 		foreach ($calendars as $calendar) {
 			$this->dispatcher->expects($this->at(0))
 				->method('dispatch')
@@ -129,7 +134,7 @@ abstract class AbstractCalDavBackend extends TestCase {
 
 			$this->backend->deleteCalendar($calendar['id']);
 		}
-		$subscriptions = $this->backend->getSubscriptionsForUser(self::UNIT_TEST_USER);
+		$subscriptions = $this->backend->getSubscriptionsForUser($principal);
 		foreach ($subscriptions as $subscription) {
 			$this->backend->deleteSubscription($subscription['id']);
 		}
diff --git a/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php b/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
index bd6a8856d51..4e343340f25 100644
--- a/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
+++ b/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
@@ -605,21 +605,21 @@ DTSTART;TZID=Europe/Warsaw:20170325T150000
 DTEND;TZID=Europe/Warsaw:20170325T160000
 TRANSP:OPAQUE
 DESCRIPTION:Magiczna treść uzyskana za pomocą magicznego proszku.\n\nę
- żźćńłóÓŻŹĆŁĘ€śśśŚŚ\n               \,\,))))))))\;\,\n  
+ żźćńłóÓŻŹĆŁĘ€śśśŚŚ\n               \,\,))))))))\;\,\n
            __))))))))))))))\,\n \\|/       -\\(((((''''((((((((.\n -*-==///
- ///((''  .     `))))))\,\n /|\\      ))| o    \;-.    '(((((              
-                     \,(\,\n          ( `|    /  )    \;))))'              
+ ///((''  .     `))))))\,\n /|\\      ))| o    \;-.    '(((((
+                     \,(\,\n          ( `|    /  )    \;))))'
                   \,_))^\;(~\n             |   |   |   \,))((((_     _____-
  -----~~~-.        %\,\;(\;(>'\;'~\n             o_)\;   \;    )))(((` ~---
  ~  `::           \\      %%~~)(v\;(`('~\n                   \;    ''''````
-          `:       `:::|\\\,__\,%%    )\;`'\; ~\n                  |   _   
-              )     /      `:|`----'     `-'\n            ______/\\/~    | 
+          `:       `:::|\\\,__\,%%    )\;`'\; ~\n                  |   _
+              )     /      `:|`----'     `-'\n            ______/\\/~    |
                  /        /\n          /~\;\;.____/\;\;'  /          ___--\
- ,-(   `\;\;\;/\n         / //  _\;______\;'------~~~~~    /\;\;/\\    /\n 
-        //  | |                        / \;   \\\;\;\,\\\n       (<_  | \; 
-                      /'\,/-----'  _>\n        \\_| ||_                    
-  //~\;~~~~~~~~~\n            `\\_|                   (\,~~  -Tua Xiong\n  
-                                   \\~\\\n                                 
+ ,-(   `\;\;\;/\n         / //  _\;______\;'------~~~~~    /\;\;/\\    /\n
+        //  | |                        / \;   \\\;\;\,\\\n       (<_  | \;
+                      /'\,/-----'  _>\n        \\_| ||_
+  //~\;~~~~~~~~~\n            `\\_|                   (\,~~  -Tua Xiong\n
+                                   \\~\\\n
      ~~\n\n
 SEQUENCE:1
 X-MOZ-GENERATION:1
@@ -999,4 +999,282 @@ EOD;
 		$this->assertEquals($calendarInfoUser['id'], $calendarInfoUser1['id']);
 		$this->assertEquals($calendarInfoUser['uri'], $calendarInfoUser1['uri']);
 	}
+
+	public function testSearchPrincipal(): void {
+		$myPublic = <<<EOD
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//dmfs.org//mimedir.icalendar//EN
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+X-LIC-LOCATION:Europe/Berlin
+BEGIN:DAYLIGHT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+DTSTART:19700329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+TZNAME:CET
+DTSTART:19701025T030000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=Europe/Berlin:20160419T130000
+SUMMARY:My Test (public)
+CLASS:PUBLIC
+TRANSP:OPAQUE
+STATUS:CONFIRMED
+DTEND;TZID=Europe/Berlin:20160419T140000
+LAST-MODIFIED:20160419T074202Z
+DTSTAMP:20160419T074202Z
+CREATED:20160419T074202Z
+UID:2e468c48-7860-492e-bc52-92fa0daeeccf.1461051722310-1
+END:VEVENT
+END:VCALENDAR
+EOD;
+		$myPrivate = <<<EOD
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//dmfs.org//mimedir.icalendar//EN
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+X-LIC-LOCATION:Europe/Berlin
+BEGIN:DAYLIGHT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+DTSTART:19700329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+TZNAME:CET
+DTSTART:19701025T030000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=Europe/Berlin:20160419T130000
+SUMMARY:My Test (private)
+CLASS:PRIVATE
+TRANSP:OPAQUE
+STATUS:CONFIRMED
+DTEND;TZID=Europe/Berlin:20160419T140000
+LAST-MODIFIED:20160419T074202Z
+DTSTAMP:20160419T074202Z
+CREATED:20160419T074202Z
+UID:2e468c48-7860-492e-bc52-92fa0daeeccf.1461051722310-2
+END:VEVENT
+END:VCALENDAR
+EOD;
+		$myConfidential = <<<EOD
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//dmfs.org//mimedir.icalendar//EN
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+X-LIC-LOCATION:Europe/Berlin
+BEGIN:DAYLIGHT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+DTSTART:19700329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+TZNAME:CET
+DTSTART:19701025T030000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=Europe/Berlin:20160419T130000
+SUMMARY:My Test (confidential)
+CLASS:CONFIDENTIAL
+TRANSP:OPAQUE
+STATUS:CONFIRMED
+DTEND;TZID=Europe/Berlin:20160419T140000
+LAST-MODIFIED:20160419T074202Z
+DTSTAMP:20160419T074202Z
+CREATED:20160419T074202Z
+UID:2e468c48-7860-492e-bc52-92fa0daeeccf.1461051722310-3
+END:VEVENT
+END:VCALENDAR
+EOD;
+
+		$sharerPublic = <<<EOD
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//dmfs.org//mimedir.icalendar//EN
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+X-LIC-LOCATION:Europe/Berlin
+BEGIN:DAYLIGHT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+DTSTART:19700329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+TZNAME:CET
+DTSTART:19701025T030000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=Europe/Berlin:20160419T130000
+SUMMARY:Sharer Test (public)
+CLASS:PUBLIC
+TRANSP:OPAQUE
+STATUS:CONFIRMED
+DTEND;TZID=Europe/Berlin:20160419T140000
+LAST-MODIFIED:20160419T074202Z
+DTSTAMP:20160419T074202Z
+CREATED:20160419T074202Z
+UID:2e468c48-7860-492e-bc52-92fa0daeeccf.1461051722310-4
+END:VEVENT
+END:VCALENDAR
+EOD;
+		$sharerPrivate = <<<EOD
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//dmfs.org//mimedir.icalendar//EN
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+X-LIC-LOCATION:Europe/Berlin
+BEGIN:DAYLIGHT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+DTSTART:19700329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+TZNAME:CET
+DTSTART:19701025T030000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=Europe/Berlin:20160419T130000
+SUMMARY:Sharer Test (private)
+CLASS:PRIVATE
+TRANSP:OPAQUE
+STATUS:CONFIRMED
+DTEND;TZID=Europe/Berlin:20160419T140000
+LAST-MODIFIED:20160419T074202Z
+DTSTAMP:20160419T074202Z
+CREATED:20160419T074202Z
+UID:2e468c48-7860-492e-bc52-92fa0daeeccf.1461051722310-5
+END:VEVENT
+END:VCALENDAR
+EOD;
+		$sharerConfidential = <<<EOD
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//dmfs.org//mimedir.icalendar//EN
+BEGIN:VTIMEZONE
+TZID:Europe/Berlin
+X-LIC-LOCATION:Europe/Berlin
+BEGIN:DAYLIGHT
+TZOFFSETFROM:+0100
+TZOFFSETTO:+0200
+TZNAME:CEST
+DTSTART:19700329T020000
+RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:+0200
+TZOFFSETTO:+0100
+TZNAME:CET
+DTSTART:19701025T030000
+RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART;TZID=Europe/Berlin:20160419T130000
+SUMMARY:Sharer Test (confidential)
+CLASS:CONFIDENTIAL
+TRANSP:OPAQUE
+STATUS:CONFIRMED
+DTEND;TZID=Europe/Berlin:20160419T140000
+LAST-MODIFIED:20160419T074202Z
+DTSTAMP:20160419T074202Z
+CREATED:20160419T074202Z
+UID:2e468c48-7860-492e-bc52-92fa0daeeccf.1461051722310-6
+END:VEVENT
+END:VCALENDAR
+EOD;
+
+		$l10n = $this->createMock(IL10N::class);
+		$l10n
+			->expects($this->any())
+			->method('t')
+			->willReturnCallback(function ($text, $parameters = []) {
+				return vsprintf($text, $parameters);
+			});
+		$config = $this->createMock(IConfig::class);
+		$this->userManager->expects($this->any())
+			->method('userExists')
+			->willReturn(true);
+		$this->groupManager->expects($this->any())
+			->method('groupExists')
+			->willReturn(true);
+
+		$me = self::UNIT_TEST_USER;
+		$sharer = self::UNIT_TEST_USER1;
+		$this->backend->createCalendar($me, 'calendar-uri-me', []);
+		$this->backend->createCalendar($sharer, 'calendar-uri-sharer', []);
+
+		$myCalendars = $this->backend->getCalendarsForUser($me);
+		$this->assertCount(1, $myCalendars);
+
+		$sharerCalendars = $this->backend->getCalendarsForUser($sharer);
+		$this->assertCount(1, $sharerCalendars);
+		$sharerCalendar = new Calendar($this->backend, $sharerCalendars[0], $l10n, $config);
+		$this->backend->updateShares($sharerCalendar, [
+			[
+				'href' => 'principal:' . $me,
+				'readOnly' => false,
+			],
+		], []);
+
+		$this->assertCount(2, $this->backend->getCalendarsForUser($me));
+
+		$this->backend->createCalendarObject($myCalendars[0]['id'], 'event0.ics', $myPublic);
+		$this->backend->createCalendarObject($myCalendars[0]['id'], 'event1.ics', $myPrivate);
+		$this->backend->createCalendarObject($myCalendars[0]['id'], 'event2.ics', $myConfidential);
+
+		$this->backend->createCalendarObject($sharerCalendars[0]['id'], 'event3.ics', $sharerPublic);
+		$this->backend->createCalendarObject($sharerCalendars[0]['id'], 'event4.ics', $sharerPrivate);
+		$this->backend->createCalendarObject($sharerCalendars[0]['id'], 'event5.ics', $sharerConfidential);
+
+		$mySearchResults = $this->backend->searchPrincipalUri($me, 'Test', ['VEVENT'], ['SUMMARY'], []);
+		$sharerSearchResults = $this->backend->searchPrincipalUri($sharer, 'Test', ['VEVENT'], ['SUMMARY'], []);
+
+		$this->assertCount(4, $mySearchResults);
+		$this->assertCount(3, $sharerSearchResults);
+
+		$this->assertEquals($myPublic, $mySearchResults[0]['calendardata']);
+		$this->assertEquals($myPrivate, $mySearchResults[1]['calendardata']);
+		$this->assertEquals($myConfidential, $mySearchResults[2]['calendardata']);
+		$this->assertEquals($sharerPublic, $mySearchResults[3]['calendardata']);
+
+		$this->assertEquals($sharerPublic, $sharerSearchResults[0]['calendardata']);
+		$this->assertEquals($sharerPrivate, $sharerSearchResults[1]['calendardata']);
+		$this->assertEquals($sharerConfidential, $sharerSearchResults[2]['calendardata']);
+	}
 }
diff --git a/apps/dav/tests/unit/Search/ContactsSearchProviderTest.php b/apps/dav/tests/unit/Search/ContactsSearchProviderTest.php
index d89d8dd1690..e0cfe3245ba 100644
--- a/apps/dav/tests/unit/Search/ContactsSearchProviderTest.php
+++ b/apps/dav/tests/unit/Search/ContactsSearchProviderTest.php
@@ -224,7 +224,7 @@ class ContactsSearchProviderTest extends TestCase {
 		$this->assertEquals('icon-contacts-dark', $result0Data['iconClass']);
 		$this->assertTrue($result0Data['rounded']);
 
-		$this->assertInstanceOf(ContactsSearchResultEntry::class, $result0);
+		$this->assertInstanceOf(ContactsSearchResultEntry::class, $result1);
 		$this->assertEquals('absolute-thumbnail-url?photo', $result1Data['thumbnailUrl']);
 		$this->assertEquals('FN of Test2', $result1Data['title']);
 		$this->assertEquals('subline', $result1Data['subline']);
diff --git a/apps/dav/tests/unit/Search/EventsSearchProviderTest.php b/apps/dav/tests/unit/Search/EventsSearchProviderTest.php
new file mode 100644
index 00000000000..f0d6329db5c
--- /dev/null
+++ b/apps/dav/tests/unit/Search/EventsSearchProviderTest.php
@@ -0,0 +1,473 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\DAV\Tests\unit\Search;
+
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCA\DAV\Search\EventsSearchProvider;
+use OCA\DAV\Search\EventsSearchResultEntry;
+use OCP\App\IAppManager;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\Search\ISearchQuery;
+use OCP\Search\SearchResult;
+use Sabre\VObject\Reader;
+use Test\TestCase;
+
+class EventsSearchProviderTest extends TestCase {
+
+	/** @var IAppManager|\PHPUnit\Framework\MockObject\MockObject */
+	private $appManager;
+
+	/** @var IL10N|\PHPUnit\Framework\MockObject\MockObject */
+	private $l10n;
+
+	/** @var IURLGenerator|\PHPUnit\Framework\MockObject\MockObject */
+	private $urlGenerator;
+
+	/** @var CalDavBackend|\PHPUnit\Framework\MockObject\MockObject */
+	private $backend;
+
+	/** @var EventsSearchProvider */
+	private $provider;
+
+	// NO SUMMARY
+	private $vEvent0 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'PRODID:-//Apple Inc.//Mac OS X 10.11.6//EN'.PHP_EOL.
+		'CALSCALE:GREGORIAN'.PHP_EOL.
+		'BEGIN:VEVENT'.PHP_EOL.
+		'CREATED:20161004T144433Z'.PHP_EOL.
+		'UID:85560E76-1B0D-47E1-A735-21625767FCA4'.PHP_EOL.
+		'DTEND;VALUE=DATE:20161008'.PHP_EOL.
+		'TRANSP:TRANSPARENT'.PHP_EOL.
+		'DTSTART;VALUE=DATE:20161005'.PHP_EOL.
+		'DTSTAMP:20161004T144437Z'.PHP_EOL.
+		'SEQUENCE:0'.PHP_EOL.
+		'END:VEVENT'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// TIMED SAME DAY
+	private $vEvent1 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'PRODID:-//Tests//'.PHP_EOL.
+		'CALSCALE:GREGORIAN'.PHP_EOL.
+		'BEGIN:VTIMEZONE'.PHP_EOL.
+		'TZID:Europe/Berlin'.PHP_EOL.
+		'BEGIN:DAYLIGHT'.PHP_EOL.
+		'TZOFFSETFROM:+0100'.PHP_EOL.
+		'RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU'.PHP_EOL.
+		'DTSTART:19810329T020000'.PHP_EOL.
+		'TZNAME:GMT+2'.PHP_EOL.
+		'TZOFFSETTO:+0200'.PHP_EOL.
+		'END:DAYLIGHT'.PHP_EOL.
+		'BEGIN:STANDARD'.PHP_EOL.
+		'TZOFFSETFROM:+0200'.PHP_EOL.
+		'RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU'.PHP_EOL.
+		'DTSTART:19961027T030000'.PHP_EOL.
+		'TZNAME:GMT+1'.PHP_EOL.
+		'TZOFFSETTO:+0100'.PHP_EOL.
+		'END:STANDARD'.PHP_EOL.
+		'END:VTIMEZONE'.PHP_EOL.
+		'BEGIN:VEVENT'.PHP_EOL.
+		'CREATED:20160809T163629Z'.PHP_EOL.
+		'UID:0AD16F58-01B3-463B-A215-FD09FC729A02'.PHP_EOL.
+		'DTEND;TZID=Europe/Berlin:20160816T100000'.PHP_EOL.
+		'TRANSP:OPAQUE'.PHP_EOL.
+		'SUMMARY:Test Europe Berlin'.PHP_EOL.
+		'DTSTART;TZID=Europe/Berlin:20160816T090000'.PHP_EOL.
+		'DTSTAMP:20160809T163632Z'.PHP_EOL.
+		'SEQUENCE:0'.PHP_EOL.
+		'END:VEVENT'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// TIMED DIFFERENT DAY
+	private $vEvent2 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'PRODID:-//Tests//'.PHP_EOL.
+		'CALSCALE:GREGORIAN'.PHP_EOL.
+		'BEGIN:VTIMEZONE'.PHP_EOL.
+		'TZID:Europe/Berlin'.PHP_EOL.
+		'BEGIN:DAYLIGHT'.PHP_EOL.
+		'TZOFFSETFROM:+0100'.PHP_EOL.
+		'RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU'.PHP_EOL.
+		'DTSTART:19810329T020000'.PHP_EOL.
+		'TZNAME:GMT+2'.PHP_EOL.
+		'TZOFFSETTO:+0200'.PHP_EOL.
+		'END:DAYLIGHT'.PHP_EOL.
+		'BEGIN:STANDARD'.PHP_EOL.
+		'TZOFFSETFROM:+0200'.PHP_EOL.
+		'RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU'.PHP_EOL.
+		'DTSTART:19961027T030000'.PHP_EOL.
+		'TZNAME:GMT+1'.PHP_EOL.
+		'TZOFFSETTO:+0100'.PHP_EOL.
+		'END:STANDARD'.PHP_EOL.
+		'END:VTIMEZONE'.PHP_EOL.
+		'BEGIN:VEVENT'.PHP_EOL.
+		'CREATED:20160809T163629Z'.PHP_EOL.
+		'UID:0AD16F58-01B3-463B-A215-FD09FC729A02'.PHP_EOL.
+		'DTEND;TZID=Europe/Berlin:20160817T100000'.PHP_EOL.
+		'TRANSP:OPAQUE'.PHP_EOL.
+		'SUMMARY:Test Europe Berlin'.PHP_EOL.
+		'DTSTART;TZID=Europe/Berlin:20160816T090000'.PHP_EOL.
+		'DTSTAMP:20160809T163632Z'.PHP_EOL.
+		'SEQUENCE:0'.PHP_EOL.
+		'END:VEVENT'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// ALL-DAY ONE-DAY
+	private $vEvent3 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'PRODID:-//Apple Inc.//Mac OS X 10.11.6//EN'.PHP_EOL.
+		'CALSCALE:GREGORIAN'.PHP_EOL.
+		'BEGIN:VEVENT'.PHP_EOL.
+		'CREATED:20161004T144433Z'.PHP_EOL.
+		'UID:85560E76-1B0D-47E1-A735-21625767FCA4'.PHP_EOL.
+		'DTEND;VALUE=DATE:20161006'.PHP_EOL.
+		'TRANSP:TRANSPARENT'.PHP_EOL.
+		'DTSTART;VALUE=DATE:20161005'.PHP_EOL.
+		'DTSTAMP:20161004T144437Z'.PHP_EOL.
+		'SEQUENCE:0'.PHP_EOL.
+		'END:VEVENT'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// ALL-DAY MULTIPLE DAYS
+	private $vEvent4 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'PRODID:-//Apple Inc.//Mac OS X 10.11.6//EN'.PHP_EOL.
+		'CALSCALE:GREGORIAN'.PHP_EOL.
+		'BEGIN:VEVENT'.PHP_EOL.
+		'CREATED:20161004T144433Z'.PHP_EOL.
+		'UID:85560E76-1B0D-47E1-A735-21625767FCA4'.PHP_EOL.
+		'DTEND;VALUE=DATE:20161008'.PHP_EOL.
+		'TRANSP:TRANSPARENT'.PHP_EOL.
+		'DTSTART;VALUE=DATE:20161005'.PHP_EOL.
+		'DTSTAMP:20161004T144437Z'.PHP_EOL.
+		'SEQUENCE:0'.PHP_EOL.
+		'END:VEVENT'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// DURATION
+	private $vEvent5 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'PRODID:-//Apple Inc.//Mac OS X 10.11.6//EN'.PHP_EOL.
+		'CALSCALE:GREGORIAN'.PHP_EOL.
+		'BEGIN:VEVENT'.PHP_EOL.
+		'CREATED:20161004T144433Z'.PHP_EOL.
+		'UID:85560E76-1B0D-47E1-A735-21625767FCA4'.PHP_EOL.
+		'DURATION:P5D'.PHP_EOL.
+		'TRANSP:TRANSPARENT'.PHP_EOL.
+		'DTSTART;VALUE=DATE:20161005'.PHP_EOL.
+		'DTSTAMP:20161004T144437Z'.PHP_EOL.
+		'SEQUENCE:0'.PHP_EOL.
+		'END:VEVENT'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// NO DTEND - DATE
+	private $vEvent6 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'PRODID:-//Apple Inc.//Mac OS X 10.11.6//EN'.PHP_EOL.
+		'CALSCALE:GREGORIAN'.PHP_EOL.
+		'BEGIN:VEVENT'.PHP_EOL.
+		'CREATED:20161004T144433Z'.PHP_EOL.
+		'UID:85560E76-1B0D-47E1-A735-21625767FCA4'.PHP_EOL.
+		'TRANSP:TRANSPARENT'.PHP_EOL.
+		'DTSTART;VALUE=DATE:20161005'.PHP_EOL.
+		'DTSTAMP:20161004T144437Z'.PHP_EOL.
+		'SEQUENCE:0'.PHP_EOL.
+		'END:VEVENT'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// NO DTEND - DATE-TIME
+	private $vEvent7 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'PRODID:-//Tests//'.PHP_EOL.
+		'CALSCALE:GREGORIAN'.PHP_EOL.
+		'BEGIN:VTIMEZONE'.PHP_EOL.
+		'TZID:Europe/Berlin'.PHP_EOL.
+		'BEGIN:DAYLIGHT'.PHP_EOL.
+		'TZOFFSETFROM:+0100'.PHP_EOL.
+		'RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU'.PHP_EOL.
+		'DTSTART:19810329T020000'.PHP_EOL.
+		'TZNAME:GMT+2'.PHP_EOL.
+		'TZOFFSETTO:+0200'.PHP_EOL.
+		'END:DAYLIGHT'.PHP_EOL.
+		'BEGIN:STANDARD'.PHP_EOL.
+		'TZOFFSETFROM:+0200'.PHP_EOL.
+		'RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU'.PHP_EOL.
+		'DTSTART:19961027T030000'.PHP_EOL.
+		'TZNAME:GMT+1'.PHP_EOL.
+		'TZOFFSETTO:+0100'.PHP_EOL.
+		'END:STANDARD'.PHP_EOL.
+		'END:VTIMEZONE'.PHP_EOL.
+		'BEGIN:VEVENT'.PHP_EOL.
+		'CREATED:20160809T163629Z'.PHP_EOL.
+		'UID:0AD16F58-01B3-463B-A215-FD09FC729A02'.PHP_EOL.
+		'TRANSP:OPAQUE'.PHP_EOL.
+		'SUMMARY:Test Europe Berlin'.PHP_EOL.
+		'DTSTART;TZID=Europe/Berlin:20160816T090000'.PHP_EOL.
+		'DTSTAMP:20160809T163632Z'.PHP_EOL.
+		'SEQUENCE:0'.PHP_EOL.
+		'END:VEVENT'.PHP_EOL.
+		'END:VCALENDAR';
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->appManager = $this->createMock(IAppManager::class);
+		$this->l10n = $this->createMock(IL10N::class);
+		$this->urlGenerator = $this->createMock(IURLGenerator::class);
+		$this->backend = $this->createMock(CalDavBackend::class);
+
+		$this->provider = new EventsSearchProvider(
+			$this->appManager,
+			$this->l10n,
+			$this->urlGenerator,
+			$this->backend
+		);
+	}
+
+	public function testGetId(): void {
+		$this->assertEquals('calendar-dav', $this->provider->getId());
+	}
+
+	public function testGetName(): void {
+		$this->l10n->expects($this->exactly(1))
+			->method('t')
+			->with('Events')
+			->willReturnArgument(0);
+
+		$this->assertEquals('Events', $this->provider->getName());
+	}
+
+	public function testSearchAppDisabled(): void {
+		$user = $this->createMock(IUser::class);
+		$query = $this->createMock(ISearchQuery::class);
+		$this->appManager->expects($this->once())
+			->method('isEnabledForUser')
+			->with('calendar', $user)
+			->willReturn(false);
+		$this->l10n->expects($this->exactly(1))
+			->method('t')
+			->willReturnArgument(0);
+		$this->backend->expects($this->never())
+			->method('getCalendarsForUser');
+		$this->backend->expects($this->never())
+			->method('getSubscriptionsForUser');
+		$this->backend->expects($this->never())
+			->method('searchPrincipalUri');
+
+		$actual = $this->provider->search($user, $query);
+		$data = $actual->jsonSerialize();
+		$this->assertInstanceOf(SearchResult::class, $actual);
+		$this->assertEquals('Events', $data['name']);
+		$this->assertEmpty($data['entries']);
+		$this->assertFalse($data['isPaginated']);
+		$this->assertNull($data['cursor']);
+	}
+
+	public function testSearch(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('john.doe');
+		$query = $this->createMock(ISearchQuery::class);
+		$query->method('getTerm')->willReturn('search term');
+		$query->method('getLimit')->willReturn(5);
+		$query->method('getCursor')->willReturn(20);
+		$this->appManager->expects($this->once())
+			->method('isEnabledForUser')
+			->with('calendar', $user)
+			->willReturn(true);
+		$this->l10n->method('t')->willReturnArgument(0);
+
+		$this->backend->expects($this->once())
+			->method('getCalendarsForUser')
+			->with('principals/users/john.doe')
+			->willReturn([
+				[
+					'id' => 99,
+					'principaluri' => 'principals/users/john.doe',
+					'uri' => 'calendar-uri-99',
+				], [
+					'id' => 123,
+					'principaluri' => 'principals/users/john.doe',
+					'uri' => 'calendar-uri-123',
+				]
+			]);
+		$this->backend->expects($this->once())
+			->method('getSubscriptionsForUser')
+			->with('principals/users/john.doe')
+			->willReturn([
+				[
+					'id' => 1337,
+					'principaluri' => 'principals/users/john.doe',
+					'uri' => 'subscription-uri-1337',
+				]
+			]);
+		$this->backend->expects($this->once())
+			->method('searchPrincipalUri')
+			->with('principals/users/john.doe', 'search term', ['VEVENT'],
+				['SUMMARY', 'LOCATION', 'DESCRIPTION', 'ATTENDEE', 'ORGANIZER', 'CATEGORIES'],
+				['ATTENDEE' => ['CN'], 'ORGANIZER' => ['CN']],
+				['limit' => 5, 'offset' => 20])
+			->willReturn([
+				[
+					'calendarid' => 99,
+					'calendartype' => CalDavBackend::CALENDAR_TYPE_CALENDAR,
+					'uri' => 'event0.ics',
+					'calendardata' => $this->vEvent0,
+				],
+				[
+					'calendarid' => 123,
+					'calendartype' => CalDavBackend::CALENDAR_TYPE_CALENDAR,
+					'uri' => 'event1.ics',
+					'calendardata' => $this->vEvent1,
+				],
+				[
+					'calendarid' => 1337,
+					'calendartype' => CalDavBackend::CALENDAR_TYPE_SUBSCRIPTION,
+					'uri' => 'event2.ics',
+					'calendardata' => $this->vEvent2,
+				]
+			]);
+
+		$provider = $this->getMockBuilder(EventsSearchProvider::class)
+			->setConstructorArgs([
+				$this->appManager,
+				$this->l10n,
+				$this->urlGenerator,
+				$this->backend,
+			])
+			->setMethods([
+				'getDeepLinkToCalendarApp',
+				'generateSubline',
+			])
+			->getMock();
+
+		$provider->expects($this->exactly(3))
+			->method('generateSubline')
+			->willReturn('subline');
+		$provider->expects($this->exactly(3))
+			->method('getDeepLinkToCalendarApp')
+			->withConsecutive(
+				['principals/users/john.doe', 'calendar-uri-99', 'event0.ics'],
+				['principals/users/john.doe', 'calendar-uri-123', 'event1.ics'],
+				['principals/users/john.doe', 'subscription-uri-1337', 'event2.ics']
+			)
+			->willReturn('deep-link-to-calendar');
+
+		$actual = $provider->search($user, $query);
+		$data = $actual->jsonSerialize();
+		$this->assertInstanceOf(SearchResult::class, $actual);
+		$this->assertEquals('Events', $data['name']);
+		$this->assertCount(3, $data['entries']);
+		$this->assertTrue($data['isPaginated']);
+		$this->assertEquals(23, $data['cursor']);
+
+		$result0 = $data['entries'][0];
+		$result0Data = $result0->jsonSerialize();
+		$result1 = $data['entries'][1];
+		$result1Data = $result1->jsonSerialize();
+		$result2 = $data['entries'][2];
+		$result2Data = $result2->jsonSerialize();
+
+		$this->assertInstanceOf(EventsSearchResultEntry::class, $result0);
+		$this->assertEmpty($result0Data['thumbnailUrl']);
+		$this->assertEquals('Untitled event', $result0Data['title']);
+		$this->assertEquals('subline', $result0Data['subline']);
+		$this->assertEquals('deep-link-to-calendar', $result0Data['resourceUrl']);
+		$this->assertEquals('icon-calendar-dark', $result0Data['iconClass']);
+		$this->assertFalse($result0Data['rounded']);
+
+		$this->assertInstanceOf(EventsSearchResultEntry::class, $result1);
+		$this->assertEmpty($result1Data['thumbnailUrl']);
+		$this->assertEquals('Test Europe Berlin', $result1Data['title']);
+		$this->assertEquals('subline', $result1Data['subline']);
+		$this->assertEquals('deep-link-to-calendar', $result1Data['resourceUrl']);
+		$this->assertEquals('icon-calendar-dark', $result1Data['iconClass']);
+		$this->assertFalse($result1Data['rounded']);
+
+		$this->assertInstanceOf(EventsSearchResultEntry::class, $result2);
+		$this->assertEmpty($result2Data['thumbnailUrl']);
+		$this->assertEquals('Test Europe Berlin', $result2Data['title']);
+		$this->assertEquals('subline', $result2Data['subline']);
+		$this->assertEquals('deep-link-to-calendar', $result2Data['resourceUrl']);
+		$this->assertEquals('icon-calendar-dark', $result2Data['iconClass']);
+		$this->assertFalse($result2Data['rounded']);
+	}
+
+	public function testGetDeepLinkToCalendarApp(): void {
+		$this->urlGenerator->expects($this->at(0))
+			->method('linkTo')
+			->with('', 'remote.php')
+			->willReturn('link-to-remote.php');
+		$this->urlGenerator->expects($this->at(1))
+			->method('linkToRoute')
+			->with('calendar.view.index')
+			->willReturn('link-to-route-calendar/');
+		$this->urlGenerator->expects($this->at(2))
+			->method('getAbsoluteURL')
+			->with('link-to-route-calendar/edit/bGluay10by1yZW1vdGUucGhwL2Rhdi9jYWxlbmRhcnMvam9obi5kb2UvZm9vL2Jhci5pY3M=')
+			->willReturn('absolute-url-to-route');
+
+		$actual = self::invokePrivate($this->provider, 'getDeepLinkToCalendarApp', ['principals/users/john.doe', 'foo', 'bar.ics']);
+
+		$this->assertEquals('absolute-url-to-route', $actual);
+	}
+
+	/**
+	 * @param string $ics
+	 * @param string $expectedSubline
+	 *
+	 * @dataProvider generateSublineDataProvider
+	 */
+	public function testGenerateSubline(string $ics, string $expectedSubline): void {
+		$vCalendar = Reader::read($ics, Reader::OPTION_FORGIVING);
+		$eventComponent = $vCalendar->VEVENT;
+
+		$this->l10n->method('l')
+			->willReturnCallback(static function (string $type, \DateTime $date, $_):string {
+				if ($type === 'time') {
+					return $date->format('H:i');
+				}
+
+				return $date->format('m-d');
+			});
+
+		$actual = self::invokePrivate($this->provider, 'generateSubline', [$eventComponent]);
+		$this->assertEquals($expectedSubline, $actual);
+	}
+
+	public function generateSublineDataProvider(): array {
+		return [
+			[$this->vEvent1, '08-16 09:00 - 10:00'],
+			[$this->vEvent2, '08-16 09:00 - 08-17 10:00'],
+			[$this->vEvent3, '10-05'],
+			[$this->vEvent4, '10-05 - 10-07'],
+			[$this->vEvent5, '10-05 - 10-09'],
+			[$this->vEvent6, '10-05'],
+			[$this->vEvent7, '08-16 09:00 - 09:00'],
+		];
+	}
+}
diff --git a/apps/dav/tests/unit/Search/TasksSearchProviderTest.php b/apps/dav/tests/unit/Search/TasksSearchProviderTest.php
new file mode 100644
index 00000000000..30f57270e95
--- /dev/null
+++ b/apps/dav/tests/unit/Search/TasksSearchProviderTest.php
@@ -0,0 +1,344 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Georg Ehrke
+ *
+ * @author Georg Ehrke <oc.list@georgehrke.com>
+ *
+ * @license AGPL-3.0
+ *
+ * This code is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License, version 3,
+ * along with this program. If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+namespace OCA\DAV\Tests\unit\Search;
+
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCA\DAV\Search\TasksSearchProvider;
+use OCA\DAV\Search\TasksSearchResultEntry;
+use OCP\App\IAppManager;
+use OCP\IL10N;
+use OCP\IURLGenerator;
+use OCP\IUser;
+use OCP\Search\ISearchQuery;
+use OCP\Search\SearchResult;
+use Sabre\VObject\Reader;
+use Test\TestCase;
+
+class TasksSearchProviderTest extends TestCase {
+
+	/** @var IAppManager|\PHPUnit\Framework\MockObject\MockObject */
+	private $appManager;
+
+	/** @var IL10N|\PHPUnit\Framework\MockObject\MockObject */
+	private $l10n;
+
+	/** @var IURLGenerator|\PHPUnit\Framework\MockObject\MockObject */
+	private $urlGenerator;
+
+	/** @var CalDavBackend|\PHPUnit\Framework\MockObject\MockObject */
+	private $backend;
+
+	/** @var TasksSearchProvider */
+	private $provider;
+
+	// NO DUE NOR COMPLETED NOR SUMMARY
+	private $vTodo0 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'PRODID:TEST'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'BEGIN:VTODO'.PHP_EOL.
+		'UID:20070313T123432Z-456553@example.com'.PHP_EOL.
+		'DTSTAMP:20070313T123432Z'.PHP_EOL.
+		'STATUS:NEEDS-ACTION'.PHP_EOL.
+		'END:VTODO'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// DUE AND COMPLETED
+	private $vTodo1 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'PRODID:TEST'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'BEGIN:VTODO'.PHP_EOL.
+		'UID:20070313T123432Z-456553@example.com'.PHP_EOL.
+		'DTSTAMP:20070313T123432Z'.PHP_EOL.
+		'COMPLETED:20070707T100000Z'.PHP_EOL.
+		'DUE;VALUE=DATE:20070501'.PHP_EOL.
+		'SUMMARY:Task title'.PHP_EOL.
+		'STATUS:NEEDS-ACTION'.PHP_EOL.
+		'END:VTODO'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// COMPLETED ONLY
+	private $vTodo2 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'PRODID:TEST'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'BEGIN:VTODO'.PHP_EOL.
+		'UID:20070313T123432Z-456553@example.com'.PHP_EOL.
+		'DTSTAMP:20070313T123432Z'.PHP_EOL.
+		'COMPLETED:20070707T100000Z'.PHP_EOL.
+		'SUMMARY:Task title'.PHP_EOL.
+		'STATUS:NEEDS-ACTION'.PHP_EOL.
+		'END:VTODO'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// DUE DATE
+	private $vTodo3 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'PRODID:TEST'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'BEGIN:VTODO'.PHP_EOL.
+		'UID:20070313T123432Z-456553@example.com'.PHP_EOL.
+		'DTSTAMP:20070313T123432Z'.PHP_EOL.
+		'DUE;VALUE=DATE:20070501'.PHP_EOL.
+		'SUMMARY:Task title'.PHP_EOL.
+		'STATUS:NEEDS-ACTION'.PHP_EOL.
+		'END:VTODO'.PHP_EOL.
+		'END:VCALENDAR';
+
+	// DUE DATETIME
+	private $vTodo4 = 'BEGIN:VCALENDAR'.PHP_EOL.
+		'PRODID:TEST'.PHP_EOL.
+		'VERSION:2.0'.PHP_EOL.
+		'BEGIN:VTODO'.PHP_EOL.
+		'UID:20070313T123432Z-456553@example.com'.PHP_EOL.
+		'DTSTAMP:20070313T123432Z'.PHP_EOL.
+		'DUE:20070709T130000Z'.PHP_EOL.
+		'SUMMARY:Task title'.PHP_EOL.
+		'STATUS:NEEDS-ACTION'.PHP_EOL.
+		'END:VTODO'.PHP_EOL.
+		'END:VCALENDAR';
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->appManager = $this->createMock(IAppManager::class);
+		$this->l10n = $this->createMock(IL10N::class);
+		$this->urlGenerator = $this->createMock(IURLGenerator::class);
+		$this->backend = $this->createMock(CalDavBackend::class);
+
+		$this->provider = new TasksSearchProvider(
+			$this->appManager,
+			$this->l10n,
+			$this->urlGenerator,
+			$this->backend
+		);
+	}
+
+	public function testGetId(): void {
+		$this->assertEquals('tasks-dav', $this->provider->getId());
+	}
+
+	public function testGetName(): void {
+		$this->l10n->expects($this->exactly(1))
+			->method('t')
+			->with('Tasks')
+			->willReturnArgument(0);
+
+		$this->assertEquals('Tasks', $this->provider->getName());
+	}
+
+	public function testSearchAppDisabled(): void {
+		$user = $this->createMock(IUser::class);
+		$query = $this->createMock(ISearchQuery::class);
+		$this->appManager->expects($this->once())
+			->method('isEnabledForUser')
+			->with('tasks', $user)
+			->willReturn(false);
+		$this->l10n->expects($this->exactly(1))
+			->method('t')
+			->willReturnArgument(0);
+		$this->backend->expects($this->never())
+			->method('getCalendarsForUser');
+		$this->backend->expects($this->never())
+			->method('getSubscriptionsForUser');
+		$this->backend->expects($this->never())
+			->method('searchPrincipalUri');
+
+		$actual = $this->provider->search($user, $query);
+		$data = $actual->jsonSerialize();
+		$this->assertInstanceOf(SearchResult::class, $actual);
+		$this->assertEquals('Tasks', $data['name']);
+		$this->assertEmpty($data['entries']);
+		$this->assertFalse($data['isPaginated']);
+		$this->assertNull($data['cursor']);
+	}
+
+	public function testSearch(): void {
+		$user = $this->createMock(IUser::class);
+		$user->method('getUID')->willReturn('john.doe');
+		$query = $this->createMock(ISearchQuery::class);
+		$query->method('getTerm')->willReturn('search term');
+		$query->method('getLimit')->willReturn(5);
+		$query->method('getCursor')->willReturn(20);
+		$this->appManager->expects($this->once())
+			->method('isEnabledForUser')
+			->with('tasks', $user)
+			->willReturn(true);
+		$this->l10n->method('t')->willReturnArgument(0);
+
+		$this->backend->expects($this->once())
+			->method('getCalendarsForUser')
+			->with('principals/users/john.doe')
+			->willReturn([
+				[
+					'id' => 99,
+					'principaluri' => 'principals/users/john.doe',
+					'uri' => 'calendar-uri-99',
+				], [
+					'id' => 123,
+					'principaluri' => 'principals/users/john.doe',
+					'uri' => 'calendar-uri-123',
+				]
+			]);
+		$this->backend->expects($this->once())
+			->method('getSubscriptionsForUser')
+			->with('principals/users/john.doe')
+			->willReturn([
+				[
+					'id' => 1337,
+					'principaluri' => 'principals/users/john.doe',
+					'uri' => 'subscription-uri-1337',
+				]
+			]);
+		$this->backend->expects($this->once())
+			->method('searchPrincipalUri')
+			->with('principals/users/john.doe', 'search term', ['VTODO'],
+				['SUMMARY', 'DESCRIPTION', 'CATEGORIES'],
+				[],
+				['limit' => 5, 'offset' => 20])
+			->willReturn([
+				[
+					'calendarid' => 99,
+					'calendartype' => CalDavBackend::CALENDAR_TYPE_CALENDAR,
+					'uri' => 'todo0.ics',
+					'calendardata' => $this->vTodo0,
+				],
+				[
+					'calendarid' => 123,
+					'calendartype' => CalDavBackend::CALENDAR_TYPE_CALENDAR,
+					'uri' => 'todo1.ics',
+					'calendardata' => $this->vTodo1,
+				],
+				[
+					'calendarid' => 1337,
+					'calendartype' => CalDavBackend::CALENDAR_TYPE_SUBSCRIPTION,
+					'uri' => 'todo2.ics',
+					'calendardata' => $this->vTodo2,
+				]
+			]);
+
+		$provider = $this->getMockBuilder(TasksSearchProvider::class)
+			->setConstructorArgs([
+				$this->appManager,
+				$this->l10n,
+				$this->urlGenerator,
+				$this->backend,
+			])
+			->setMethods([
+				'getDeepLinkToTasksApp',
+				'generateSubline',
+			])
+			->getMock();
+
+		$provider->expects($this->exactly(3))
+			->method('generateSubline')
+			->willReturn('subline');
+		$provider->expects($this->exactly(3))
+			->method('getDeepLinkToTasksApp')
+			->withConsecutive(
+				['calendar-uri-99', 'todo0.ics'],
+				['calendar-uri-123', 'todo1.ics'],
+				['subscription-uri-1337', 'todo2.ics']
+			)
+			->willReturn('deep-link-to-tasks');
+
+		$actual = $provider->search($user, $query);
+		$data = $actual->jsonSerialize();
+		$this->assertInstanceOf(SearchResult::class, $actual);
+		$this->assertEquals('Tasks', $data['name']);
+		$this->assertCount(3, $data['entries']);
+		$this->assertTrue($data['isPaginated']);
+		$this->assertEquals(23, $data['cursor']);
+
+		$result0 = $data['entries'][0];
+		$result0Data = $result0->jsonSerialize();
+		$result1 = $data['entries'][1];
+		$result1Data = $result1->jsonSerialize();
+		$result2 = $data['entries'][2];
+		$result2Data = $result2->jsonSerialize();
+
+		$this->assertInstanceOf(TasksSearchResultEntry::class, $result0);
+		$this->assertEmpty($result0Data['thumbnailUrl']);
+		$this->assertEquals('Untitled task', $result0Data['title']);
+		$this->assertEquals('subline', $result0Data['subline']);
+		$this->assertEquals('deep-link-to-tasks', $result0Data['resourceUrl']);
+		$this->assertEquals('icon-checkmark', $result0Data['iconClass']);
+		$this->assertFalse($result0Data['rounded']);
+
+		$this->assertInstanceOf(TasksSearchResultEntry::class, $result1);
+		$this->assertEmpty($result1Data['thumbnailUrl']);
+		$this->assertEquals('Task title', $result1Data['title']);
+		$this->assertEquals('subline', $result1Data['subline']);
+		$this->assertEquals('deep-link-to-tasks', $result1Data['resourceUrl']);
+		$this->assertEquals('icon-checkmark', $result1Data['iconClass']);
+		$this->assertFalse($result1Data['rounded']);
+
+		$this->assertInstanceOf(TasksSearchResultEntry::class, $result2);
+		$this->assertEmpty($result2Data['thumbnailUrl']);
+		$this->assertEquals('Task title', $result2Data['title']);
+		$this->assertEquals('subline', $result2Data['subline']);
+		$this->assertEquals('deep-link-to-tasks', $result2Data['resourceUrl']);
+		$this->assertEquals('icon-checkmark', $result2Data['iconClass']);
+		$this->assertFalse($result2Data['rounded']);
+	}
+
+	public function testGetDeepLinkToTasksApp(): void {
+		$this->urlGenerator->expects($this->once())
+			->method('linkToRoute')
+			->with('tasks.page.index')
+			->willReturn('link-to-route-tasks.index');
+		$this->urlGenerator->expects($this->once())
+			->method('getAbsoluteURL')
+			->with('link-to-route-tasks.index#/calendars/uri-john.doe/tasks/task-uri.ics')
+			->willReturn('absolute-url-link-to-route-tasks.index#/calendars/uri-john.doe/tasks/task-uri.ics');
+
+		$actual = self::invokePrivate($this->provider, 'getDeepLinkToTasksApp', ['uri-john.doe', 'task-uri.ics']);
+		$this->assertEquals('absolute-url-link-to-route-tasks.index#/calendars/uri-john.doe/tasks/task-uri.ics', $actual);
+	}
+
+	/**
+	 * @param string $ics
+	 * @param string $expectedSubline
+	 *
+	 * @dataProvider generateSublineDataProvider
+	 */
+	public function testGenerateSubline(string $ics, string $expectedSubline): void {
+		$vCalendar = Reader::read($ics, Reader::OPTION_FORGIVING);
+		$taskComponent = $vCalendar->VTODO;
+
+		$this->l10n->method('t')->willReturnArgument(0);
+		$this->l10n->method('l')->willReturnArgument('');
+
+		$actual = self::invokePrivate($this->provider, 'generateSubline', [$taskComponent]);
+		$this->assertEquals($expectedSubline, $actual);
+	}
+
+	public function generateSublineDataProvider(): array {
+		return [
+			[$this->vTodo0, ''],
+			[$this->vTodo1, 'Completed on %s'],
+			[$this->vTodo2, 'Completed on %s'],
+			[$this->vTodo3, 'Due on %s'],
+			[$this->vTodo4, 'Due on %s by %s'],
+		];
+	}
+}