From ace08819f98b346b713b7ae2639582a7b9d0261e Mon Sep 17 00:00:00 2001
From: Richard Steinmetz <richard@steinmetz.cloud>
Date: Wed, 20 Sep 2023 17:45:54 +0200
Subject: [PATCH] fix(dav): expand recurrences when searching

Signed-off-by: Richard Steinmetz <richard@steinmetz.cloud>
---
 apps/dav/lib/CalDAV/CalDavBackend.php         | 13 +++-
 .../tests/unit/CalDAV/CalDavBackendTest.php   | 69 +++++++++++++++++++
 2 files changed, 81 insertions(+), 1 deletion(-)

diff --git a/apps/dav/lib/CalDAV/CalDavBackend.php b/apps/dav/lib/CalDAV/CalDavBackend.php
index 915976d7dd3..5f2fe7e5dce 100644
--- a/apps/dav/lib/CalDAV/CalDavBackend.php
+++ b/apps/dav/lib/CalDAV/CalDavBackend.php
@@ -20,6 +20,7 @@
  * @author Thomas Citharel <nextcloud@tcit.fr>
  * @author Thomas Müller <thomas.mueller@tmit.eu>
  * @author Vinicius Cubas Brand <vinicius@eita.org.br>
+ * @author Richard Steinmetz <richard@steinmetz.cloud>
  *
  * @license AGPL-3.0
  *
@@ -1959,8 +1960,18 @@ class CalDavBackend extends AbstractBackend implements SyncSupport, Subscription
 		});
 		$result->closeCursor();
 
-		return array_map(function ($o) {
+		return array_map(function ($o) use ($options) {
 			$calendarData = Reader::read($o['calendardata']);
+
+			// Expand recurrences if an explicit time range is requested
+			if ($calendarData instanceof VCalendar
+				&& isset($options['timerange']['start'], $options['timerange']['end'])) {
+				$calendarData = $calendarData->expand(
+					$options['timerange']['start'],
+					$options['timerange']['end'],
+				);
+			}
+
 			$comps = $calendarData->getComponents();
 			$objects = [];
 			$timezones = [];
diff --git a/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php b/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
index 3da6ca61b7e..b23091275ef 100644
--- a/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
+++ b/apps/dav/tests/unit/CalDAV/CalDavBackendTest.php
@@ -32,7 +32,9 @@
 
 namespace OCA\DAV\Tests\unit\CalDAV;
 
+use DateInterval;
 use DateTime;
+use DateTimeImmutable;
 use DateTimeZone;
 use OCA\DAV\CalDAV\CalDavBackend;
 use OCA\DAV\CalDAV\Calendar;
@@ -1420,4 +1422,71 @@ EOD;
 		// Check that no crash occurs when prune is called without current changes
 		$deleted = $this->backend->pruneOutdatedSyncTokens(1);
 	}
+
+	public function testSearchAndExpandRecurrences() {
+		$calendarId = $this->createTestCalendar();
+		$calendarInfo = [
+			'id' => $calendarId,
+			'principaluri' => 'user1',
+			'{http://owncloud.org/ns}owner-principal' => 'user1',
+		];
+
+		$calData = <<<'EOD'
+BEGIN:VCALENDAR
+PRODID:-//IDN nextcloud.com//Calendar app 4.5.0-alpha.2//EN
+CALSCALE:GREGORIAN
+VERSION:2.0
+BEGIN:VEVENT
+CREATED:20230921T133401Z
+DTSTAMP:20230921T133448Z
+LAST-MODIFIED:20230921T133448Z
+SEQUENCE:2
+UID:7b7d5d12-683c-48ce-973a-b3e1cb0bae2a
+DTSTART;VALUE=DATE:20230912
+DTEND;VALUE=DATE:20230913
+STATUS:CONFIRMED
+SUMMARY:Daily Event
+RRULE:FREQ=DAILY
+END:VEVENT
+END:VCALENDAR
+EOD;
+		$uri = static::getUniqueID('calobj');
+		$this->backend->createCalendarObject($calendarId, $uri, $calData);
+
+		$start = new DateTimeImmutable('2023-09-20T00:00:00Z');
+		$end = $start->add(new DateInterval('P14D'));
+
+		$results = $this->backend->search(
+			$calendarInfo,
+			'',
+			[],
+			[
+				'timerange' => [
+					'start' => $start,
+					'end' => $end,
+				]
+			],
+			null,
+			null,
+		);
+
+		$this->assertCount(1, $results);
+		$this->assertCount(14, $results[0]['objects']);
+		foreach ($results as $result) {
+			foreach ($result['objects'] as $object) {
+				$this->assertEquals($object['UID'][0], '7b7d5d12-683c-48ce-973a-b3e1cb0bae2a');
+				$this->assertEquals($object['SUMMARY'][0], 'Daily Event');
+				$this->assertGreaterThanOrEqual(
+					$start->getTimestamp(),
+					$object['DTSTART'][0]->getTimestamp(),
+					'Recurrence starting before requested start',
+				);
+				$this->assertLessThanOrEqual(
+					$end->getTimestamp(),
+					$object['DTSTART'][0]->getTimestamp(),
+					'Recurrence starting after requested end',
+				);
+			}
+		}
+	}
 }
-- 
2.39.5