feat(webcal): only update modified and deleted events from webcal calendars

apps/dav/composer/composer/autoload_classmap.php

@@ -117,6 +117,7 @@
     'OCA\\DAV\\CalDAV\\Trashbin\\RestoreTarget' => $baseDir . '/../lib/CalDAV/Trashbin/RestoreTarget.php',
     'OCA\\DAV\\CalDAV\\Trashbin\\TrashbinHome' => $baseDir . '/../lib/CalDAV/Trashbin/TrashbinHome.php',
     'OCA\\DAV\\CalDAV\\Validation\\CalDavValidatePlugin' => $baseDir . '/../lib/CalDAV/Validation/CalDavValidatePlugin.php',
+    'OCA\\DAV\\CalDAV\\WebcalCaching\\Connection' => $baseDir . '/../lib/CalDAV/WebcalCaching/Connection.php',
     'OCA\\DAV\\CalDAV\\WebcalCaching\\Plugin' => $baseDir . '/../lib/CalDAV/WebcalCaching/Plugin.php',
     'OCA\\DAV\\CalDAV\\WebcalCaching\\RefreshWebcalService' => $baseDir . '/../lib/CalDAV/WebcalCaching/RefreshWebcalService.php',
     'OCA\\DAV\\Capabilities' => $baseDir . '/../lib/Capabilities.php',

apps/dav/composer/composer/autoload_static.php

@@ -132,6 +132,7 @@ class ComposerStaticInitDAV
         'OCA\\DAV\\CalDAV\\Trashbin\\RestoreTarget' => __DIR__ . '/..' . '/../lib/CalDAV/Trashbin/RestoreTarget.php',
         'OCA\\DAV\\CalDAV\\Trashbin\\TrashbinHome' => __DIR__ . '/..' . '/../lib/CalDAV/Trashbin/TrashbinHome.php',
         'OCA\\DAV\\CalDAV\\Validation\\CalDavValidatePlugin' => __DIR__ . '/..' . '/../lib/CalDAV/Validation/CalDavValidatePlugin.php',
+        'OCA\\DAV\\CalDAV\\WebcalCaching\\Connection' => __DIR__ . '/..' . '/../lib/CalDAV/WebcalCaching/Connection.php',
         'OCA\\DAV\\CalDAV\\WebcalCaching\\Plugin' => __DIR__ . '/..' . '/../lib/CalDAV/WebcalCaching/Plugin.php',
         'OCA\\DAV\\CalDAV\\WebcalCaching\\RefreshWebcalService' => __DIR__ . '/..' . '/../lib/CalDAV/WebcalCaching/RefreshWebcalService.php',
         'OCA\\DAV\\Capabilities' => __DIR__ . '/..' . '/../lib/Capabilities.php',

apps/dav/lib/CalDAV/CalDavBackend.php

@@ -945,6 +945,43 @@ public function restoreCalendar(int $id): void {
 		}, $this->db);
 	}
 
+	/**
+	 * Returns all calendar objects with limited metadata for a calendar
+	 *
+	 * Every item contains an array with the following keys:
+	 *   * id - the table row id
+	 *   * etag - An arbitrary string
+	 *   * uri - a unique key which will be used to construct the uri. This can
+	 *     be any arbitrary string.
+	 *   * calendardata - The iCalendar-compatible calendar data
+	 *
+	 * @param mixed $calendarId
+	 * @param int $calendarType
+	 * @return array
+	 */
+	public function getLimitedCalendarObjects(int $calendarId, int $calendarType = self::CALENDAR_TYPE_CALENDAR):array {
+		$query = $this->db->getQueryBuilder();
+		$query->select(['id','uid', 'etag', 'uri', 'calendardata'])
+			->from('calendarobjects')
+			->where($query->expr()->eq('calendarid', $query->createNamedParameter($calendarId)))
+			->andWhere($query->expr()->eq('calendartype', $query->createNamedParameter($calendarType)))
+			->andWhere($query->expr()->isNull('deleted_at'));
+		$stmt = $query->executeQuery();
+
+		$result = [];
+		while (($row = $stmt->fetch()) !== false) {
+			$result[$row['uid']] = [
+				'id' => $row['id'],
+				'etag' => $row['etag'],
+				'uri' => $row['uri'],
+				'calendardata' => $row['calendardata'],
+			];
+		}
+		$stmt->closeCursor();
+
+		return $result;
+	}
+
 	/**
 	 * Delete all of an user's shares
 	 *
@@ -3264,6 +3301,45 @@ public function purgeAllCachedEventsForSubscription($subscriptionId) {
 		}, $this->db);
 	}
 
+	/**
+	 * @param int $subscriptionId
+	 * @param array<int> $calendarObjectIds
+	 * @param array<string> $calendarObjectUris
+	 */
+	public function purgeCachedEventsForSubscription(int $subscriptionId, array $calendarObjectIds, array $calendarObjectUris): void {
+		if(empty($calendarObjectUris)) {
+			return;
+		}
+
+		$this->atomic(function () use ($subscriptionId, $calendarObjectIds, $calendarObjectUris) {
+			foreach (array_chunk($calendarObjectIds, 1000) as $chunk) {
+				$query = $this->db->getQueryBuilder();
+				$query->delete($this->dbObjectPropertiesTable)
+					->where($query->expr()->eq('calendarid', $query->createNamedParameter($subscriptionId)))
+					->andWhere($query->expr()->eq('calendartype', $query->createNamedParameter(self::CALENDAR_TYPE_SUBSCRIPTION)))
+					->andWhere($query->expr()->in('id', $query->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY), IQueryBuilder::PARAM_INT_ARRAY))
+					->executeStatement();
+
+				$query = $this->db->getQueryBuilder();
+				$query->delete('calendarobjects')
+					->where($query->expr()->eq('calendarid', $query->createNamedParameter($subscriptionId)))
+					->andWhere($query->expr()->eq('calendartype', $query->createNamedParameter(self::CALENDAR_TYPE_SUBSCRIPTION)))
+					->andWhere($query->expr()->in('id', $query->createNamedParameter($chunk, IQueryBuilder::PARAM_INT_ARRAY), IQueryBuilder::PARAM_INT_ARRAY))
+					->executeStatement();
+			}
+
+			foreach (array_chunk($calendarObjectUris, 1000) as $chunk) {
+				$query = $this->db->getQueryBuilder();
+				$query->delete('calendarchanges')
+					->where($query->expr()->eq('calendarid', $query->createNamedParameter($subscriptionId)))
+					->andWhere($query->expr()->eq('calendartype', $query->createNamedParameter(self::CALENDAR_TYPE_SUBSCRIPTION)))
+					->andWhere($query->expr()->in('uri', $query->createNamedParameter($chunk, IQueryBuilder::PARAM_STR_ARRAY), IQueryBuilder::PARAM_STR_ARRAY))
+					->executeStatement();
+			}
+			$this->addChanges($subscriptionId, $calendarObjectUris, 3, self::CALENDAR_TYPE_SUBSCRIPTION);
+		}, $this->db);
+	}
+
 	/**
 	 * Move a calendar from one user to another
 	 *

apps/dav/lib/CalDAV/WebcalCaching/Connection.php

@@ -0,0 +1,170 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\DAV\CalDAV\WebcalCaching;
+
+use Exception;
+use GuzzleHttp\HandlerStack;
+use GuzzleHttp\Middleware;
+use OCP\Http\Client\IClientService;
+use OCP\Http\Client\LocalServerException;
+use OCP\IAppConfig;
+use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\ResponseInterface;
+use Psr\Log\LoggerInterface;
+use Sabre\DAV\Xml\Property\Href;
+use Sabre\VObject\Reader;
+
+class Connection {
+	public function __construct(private IClientService $clientService,
+		private IAppConfig $config,
+		private LoggerInterface $logger) {
+	}
+
+	/**
+	 * gets webcal feed from remote server
+	 */
+	public function queryWebcalFeed(array $subscription, array &$mutations): ?string {
+		$client = $this->clientService->newClient();
+
+		$didBreak301Chain = false;
+		$latestLocation = null;
+
+		$handlerStack = HandlerStack::create();
+		$handlerStack->push(Middleware::mapRequest(function (RequestInterface $request) {
+			return $request
+				->withHeader('Accept', 'text/calendar, application/calendar+json, application/calendar+xml')
+				->withHeader('User-Agent', 'Nextcloud Webcal Service');
+		}));
+		$handlerStack->push(Middleware::mapResponse(function (ResponseInterface $response) use (&$didBreak301Chain, &$latestLocation) {
+			if (!$didBreak301Chain) {
+				if ($response->getStatusCode() !== 301) {
+					$didBreak301Chain = true;
+				} else {
+					$latestLocation = $response->getHeader('Location');
+				}
+			}
+			return $response;
+		}));
+
+		$allowLocalAccess = $this->config->getValueString('dav', 'webcalAllowLocalAccess', 'no');
+		$subscriptionId = $subscription['id'];
+		$url = $this->cleanURL($subscription['source']);
+		if ($url === null) {
+			return null;
+		}
+
+		try {
+			$params = [
+				'allow_redirects' => [
+					'redirects' => 10
+				],
+				'handler' => $handlerStack,
+				'nextcloud' => [
+					'allow_local_address' => $allowLocalAccess === 'yes',
+				]
+			];
+
+			$user = parse_url($subscription['source'], PHP_URL_USER);
+			$pass = parse_url($subscription['source'], PHP_URL_PASS);
+			if ($user !== null && $pass !== null) {
+				$params['auth'] = [$user, $pass];
+			}
+
+			$response = $client->get($url, $params);
+			$body = $response->getBody();
+
+			if ($latestLocation !== null) {
+				$mutations['{http://calendarserver.org/ns/}source'] = new Href($latestLocation);
+			}
+
+			$contentType = $response->getHeader('Content-Type');
+			$contentType = explode(';', $contentType, 2)[0];
+			switch ($contentType) {
+				case 'application/calendar+json':
+					try {
+						$jCalendar = Reader::readJson($body, Reader::OPTION_FORGIVING);
+					} catch (Exception $ex) {
+						// In case of a parsing error return null
+						$this->logger->warning("Subscription $subscriptionId could not be parsed", ['exception' => $ex]);
+						return null;
+					}
+					return $jCalendar->serialize();
+
+				case 'application/calendar+xml':
+					try {
+						$xCalendar = Reader::readXML($body);
+					} catch (Exception $ex) {
+						// In case of a parsing error return null
+						$this->logger->warning("Subscription $subscriptionId could not be parsed", ['exception' => $ex]);
+						return null;
+					}
+					return $xCalendar->serialize();
+
+				case 'text/calendar':
+				default:
+					try {
+						$vCalendar = Reader::read($body);
+					} catch (Exception $ex) {
+						// In case of a parsing error return null
+						$this->logger->warning("Subscription $subscriptionId could not be parsed", ['exception' => $ex]);
+						return null;
+					}
+					return $vCalendar->serialize();
+			}
+		} catch (LocalServerException $ex) {
+			$this->logger->warning("Subscription $subscriptionId was not refreshed because it violates local access rules", [
+				'exception' => $ex,
+			]);
+
+			return null;
+		} catch (Exception $ex) {
+			$this->logger->warning("Subscription $subscriptionId could not be refreshed due to a network error", [
+				'exception' => $ex,
+			]);
+
+			return null;
+		}
+	}
+
+	/**
+	 * This method will strip authentication information and replace the
+	 * 'webcal' or 'webcals' protocol scheme
+	 *
+	 * @param string $url
+	 * @return string|null
+	 */
+	private function cleanURL(string $url): ?string {
+		$parsed = parse_url($url);
+		if ($parsed === false) {
+			return null;
+		}
+
+		if (isset($parsed['scheme']) && $parsed['scheme'] === 'http') {
+			$scheme = 'http';
+		} else {
+			$scheme = 'https';
+		}
+
+		$host = $parsed['host'] ?? '';
+		$port = isset($parsed['port']) ? ':' . $parsed['port'] : '';
+		$path = $parsed['path'] ?? '';
+		$query = isset($parsed['query']) ? '?' . $parsed['query'] : '';
+		$fragment = isset($parsed['fragment']) ? '#' . $parsed['fragment'] : '';
+
+		$cleanURL = "$scheme://$host$port$path$query$fragment";
+		// parse_url is giving some weird results if no url and no :// is given,
+		// so let's test the url again
+		$parsedClean = parse_url($cleanURL);
+		if ($parsedClean === false || !isset($parsedClean['host'])) {
+			return null;
+		}
+
+		return $cleanURL;
+	}
+}