Merge pull request #30963 from nextcloud/feat/calendar-migration

1 files changed, 460 insertions, 0 deletions

diff --git a/apps/dav/lib/UserMigration/CalendarMigrator.php b/apps/dav/lib/UserMigration/CalendarMigrator.php
new file mode 100644
index 00000000000..d0d9e94351b
--- /dev/null
+++ b/apps/dav/lib/UserMigration/CalendarMigrator.php
@@ -0,0 +1,460 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2022 Christopher Ng <chrng8@gmail.com>
+ *
+ * @author Christopher Ng <chrng8@gmail.com>
+ *
+ * @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\UserMigration;
+
+use function Safe\substr;
+use OCA\DAV\AppInfo\Application;
+use OCA\DAV\CalDAV\CalDavBackend;
+use OCA\DAV\CalDAV\ICSExportPlugin\ICSExportPlugin;
+use OCA\DAV\CalDAV\Plugin as CalDAVPlugin;
+use OCA\DAV\Connector\Sabre\CachingTree;
+use OCA\DAV\Connector\Sabre\Server as SabreDavServer;
+use OCA\DAV\RootCollection;
+use OCP\Calendar\ICalendar;
+use OCP\Calendar\IManager as ICalendarManager;
+use OCP\Defaults;
+use OCP\IL10N;
+use OCP\IUser;
+use OCP\UserMigration\IExportDestination;
+use OCP\UserMigration\IImportSource;
+use OCP\UserMigration\IMigrator;
+use OCP\UserMigration\TMigratorBasicVersionHandling;
+use Sabre\VObject\Component as VObjectComponent;
+use Sabre\VObject\Component\VCalendar;
+use Sabre\VObject\Component\VTimeZone;
+use Sabre\VObject\Property\ICalendar\DateTime;
+use Sabre\VObject\Reader as VObjectReader;
+use Sabre\VObject\UUIDUtil;
+use Safe\Exceptions\StringsException;
+use Symfony\Component\Console\Output\OutputInterface;
+use Throwable;
+
+class CalendarMigrator implements IMigrator {
+
+	use TMigratorBasicVersionHandling;
+
+	private CalDavBackend $calDavBackend;
+
+	private ICalendarManager $calendarManager;
+
+	// ICSExportPlugin is injected as the mergeObjects() method is required and is not to be used as a SabreDAV server plugin
+	private ICSExportPlugin $icsExportPlugin;
+
+	private Defaults $defaults;
+
+	private IL10N $l10n;
+
+	private SabreDavServer $sabreDavServer;
+
+	private const USERS_URI_ROOT = 'principals/users/';
+
+	private const FILENAME_EXT = '.ics';
+
+	private const MIGRATED_URI_PREFIX = 'migrated-';
+
+	private const EXPORT_ROOT = Application::APP_ID . '/calendars/';
+
+	public function __construct(
+		CalDavBackend $calDavBackend,
+		ICalendarManager $calendarManager,
+		ICSExportPlugin $icsExportPlugin,
+		Defaults $defaults,
+		IL10N $l10n
+	) {
+		$this->calDavBackend = $calDavBackend;
+		$this->calendarManager = $calendarManager;
+		$this->icsExportPlugin = $icsExportPlugin;
+		$this->defaults = $defaults;
+		$this->l10n = $l10n;
+
+		$root = new RootCollection();
+		$this->sabreDavServer = new SabreDavServer(new CachingTree($root));
+		$this->sabreDavServer->addPlugin(new CalDAVPlugin());
+	}
+
+	private function getPrincipalUri(IUser $user): string {
+		return CalendarMigrator::USERS_URI_ROOT . $user->getUID();
+	}
+
+	/**
+	 * @return array{name: string, vCalendar: VCalendar}
+	 *
+	 * @throws CalendarMigratorException
+	 * @throws InvalidCalendarException
+	 */
+	private function getCalendarExportData(IUser $user, ICalendar $calendar, OutputInterface $output): array {
+		$userId = $user->getUID();
+		$calendarId = $calendar->getKey();
+		$calendarInfo = $this->calDavBackend->getCalendarById($calendarId);
+
+		if (empty($calendarInfo)) {
+			throw new CalendarMigratorException("Invalid info for calendar ID $calendarId");
+		}
+
+		$uri = $calendarInfo['uri'];
+		$path = CalDAVPlugin::CALENDAR_ROOT . "/$userId/$uri";
+
+		/**
+		 * @see \Sabre\CalDAV\ICSExportPlugin::httpGet() implementation reference
+		 */
+
+		$properties = $this->sabreDavServer->getProperties($path, [
+			'{DAV:}resourcetype',
+			'{DAV:}displayname',
+			'{http://sabredav.org/ns}sync-token',
+			'{DAV:}sync-token',
+			'{http://apple.com/ns/ical/}calendar-color',
+		]);
+
+		// Filter out invalid (e.g. deleted) calendars
+		if (!isset($properties['{DAV:}resourcetype']) || !$properties['{DAV:}resourcetype']->is('{' . CalDAVPlugin::NS_CALDAV . '}calendar')) {
+			throw new InvalidCalendarException();
+		}
+
+		/**
+		 * @see \Sabre\CalDAV\ICSExportPlugin::generateResponse() implementation reference
+		 */
+
+		$calDataProp = '{' . CalDAVPlugin::NS_CALDAV . '}calendar-data';
+		$calendarNode = $this->sabreDavServer->tree->getNodeForPath($path);
+		$nodes = $this->sabreDavServer->getPropertiesIteratorForPath($path, [$calDataProp], 1);
+
+		$blobs = [];
+		foreach ($nodes as $node) {
+			if (isset($node[200][$calDataProp])) {
+				$blobs[$node['href']] = $node[200][$calDataProp];
+			}
+		}
+
+		$mergedCalendar = $this->icsExportPlugin->mergeObjects(
+			$properties,
+			$blobs,
+		);
+
+		$problems = $mergedCalendar->validate();
+		if (!empty($problems)) {
+			$output->writeln('Skipping calendar "' . $properties['{DAV:}displayname'] . '" containing invalid calendar data');
+			throw new InvalidCalendarException();
+		}
+
+		return [
+			'name' => $calendarNode->getName(),
+			'vCalendar' => $mergedCalendar,
+		];
+	}
+
+	/**
+	 * @return array<int, array{name: string, vCalendar: VCalendar}>
+	 *
+	 * @throws CalendarMigratorException
+	 */
+	private function getCalendarExports(IUser $user, OutputInterface $output): array {
+		$principalUri = $this->getPrincipalUri($user);
+
+		return array_values(array_filter(array_map(
+			function (ICalendar $calendar) use ($user, $output) {
+				try {
+					return $this->getCalendarExportData($user, $calendar, $output);
+				} catch (InvalidCalendarException $e) {
+					// Allow this exception as invalid (e.g. deleted) calendars are not to be exported
+					return null;
+				}
+			},
+			$this->calendarManager->getCalendarsForPrincipal($principalUri),
+		)));
+	}
+
+	private function getUniqueCalendarUri(IUser $user, string $initialCalendarUri): string {
+		$principalUri = $this->getPrincipalUri($user);
+		try {
+			$initialCalendarUri = substr($initialCalendarUri, 0, strlen(CalendarMigrator::MIGRATED_URI_PREFIX)) === CalendarMigrator::MIGRATED_URI_PREFIX
+				? $initialCalendarUri
+				: CalendarMigrator::MIGRATED_URI_PREFIX . $initialCalendarUri;
+		} catch (StringsException $e) {
+			throw new CalendarMigratorException('Failed to get unique calendar URI', 0, $e);
+		}
+
+		$existingCalendarUris = array_map(
+			fn (ICalendar $calendar) => $calendar->getUri(),
+			$this->calendarManager->getCalendarsForPrincipal($principalUri),
+		);
+
+		$calendarUri = $initialCalendarUri;
+		$acc = 1;
+		while (in_array($calendarUri, $existingCalendarUris, true)) {
+			$calendarUri = $initialCalendarUri . "-$acc";
+			++$acc;
+		}
+
+		return $calendarUri;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function export(IUser $user, IExportDestination $exportDestination, OutputInterface $output): void {
+		$output->writeln('Exporting calendars into ' . CalendarMigrator::EXPORT_ROOT . '…');
+
+		$calendarExports = $this->getCalendarExports($user, $output);
+
+		if (empty($calendarExports)) {
+			$output->writeln('No calendars to export…');
+		}
+
+		/**
+		 * @var string $name
+		 * @var VCalendar $vCalendar
+		 */
+		foreach ($calendarExports as ['name' => $name, 'vCalendar' => $vCalendar]) {
+			// Set filename to sanitized calendar name appended with the date
+			$filename = preg_replace('/[^a-zA-Z0-9-_ ]/um', '', $name) . '_' . date('Y-m-d') . CalendarMigrator::FILENAME_EXT;
+			$exportPath = CalendarMigrator::EXPORT_ROOT . $filename;
+
+			if ($exportDestination->addFileContents($exportPath, $vCalendar->serialize()) === false) {
+				throw new CalendarMigratorException('Could not export calendars');
+			}
+		}
+	}
+
+	/**
+	 * @return array<string, VTimeZone>
+	 */
+	private function getCalendarTimezones(VCalendar $vCalendar): array {
+		/** @var VTimeZone[] $calendarTimezones */
+		$calendarTimezones = array_filter(
+			$vCalendar->getComponents(),
+			fn ($component) => $component->name === 'VTIMEZONE',
+		);
+
+		/** @var array<string, VTimeZone> $calendarTimezoneMap */
+		$calendarTimezoneMap = [];
+		foreach ($calendarTimezones as $vTimeZone) {
+			$calendarTimezoneMap[$vTimeZone->getTimeZone()->getName()] = $vTimeZone;
+		}
+
+		return $calendarTimezoneMap;
+	}
+
+	/**
+	 * @return VTimeZone[]
+	 */
+	private function getTimezonesForComponent(VCalendar $vCalendar, VObjectComponent $component): array {
+		$componentTimezoneIds = [];
+
+		foreach ($component->children() as $child) {
+			if ($child instanceof DateTime && isset($child->parameters['TZID'])) {
+				$timezoneId = $child->parameters['TZID']->getValue();
+				if (!in_array($timezoneId, $componentTimezoneIds, true)) {
+					$componentTimezoneIds[] = $timezoneId;
+				}
+			}
+		}
+
+		$calendarTimezoneMap = $this->getCalendarTimezones($vCalendar);
+
+		return array_values(array_filter(array_map(
+			fn (string $timezoneId) => $calendarTimezoneMap[$timezoneId],
+			$componentTimezoneIds,
+		)));
+	}
+
+	private function sanitizeComponent(VObjectComponent $component): VObjectComponent {
+		// Operate on the component clone to prevent mutation of the original
+		$component = clone $component;
+
+		// Remove RSVP parameters to prevent automatically sending invitation emails to attendees on import
+		foreach ($component->children() as $child) {
+			if (
+				$child->name === 'ATTENDEE'
+				&& isset($child->parameters['RSVP'])
+			) {
+				unset($child->parameters['RSVP']);
+			}
+		}
+
+		return $component;
+	}
+
+	/**
+	 * @return VObjectComponent[]
+	 */
+	private function getRequiredImportComponents(VCalendar $vCalendar, VObjectComponent $component): array {
+		$component = $this->sanitizeComponent($component);
+		/** @var array<int, VTimeZone> $timezoneComponents */
+		$timezoneComponents = $this->getTimezonesForComponent($vCalendar, $component);
+		return [
+			...$timezoneComponents,
+			$component,
+		];
+	}
+
+	private function initCalendarObject(): VCalendar {
+		$vCalendarObject = new VCalendar();
+		$vCalendarObject->PRODID = '-//IDN nextcloud.com//Migrated calendar//EN';
+		return $vCalendarObject;
+	}
+
+	private function importCalendarObject(int $calendarId, VCalendar $vCalendarObject, OutputInterface $output): void {
+		try {
+			$this->calDavBackend->createCalendarObject(
+				$calendarId,
+				UUIDUtil::getUUID() . CalendarMigrator::FILENAME_EXT,
+				$vCalendarObject->serialize(),
+				CalDavBackend::CALENDAR_TYPE_CALENDAR,
+			);
+		} catch (Throwable $e) {
+			// Rollback creation of calendar on error
+			$output->writeln('Error creating calendar object, rolling back creation of calendar…');
+			$this->calDavBackend->deleteCalendar($calendarId, true);
+		}
+	}
+
+	/**
+	 * @throws CalendarMigratorException
+	 */
+	private function importCalendar(IUser $user, string $filename, string $initialCalendarUri, VCalendar $vCalendar, OutputInterface $output): void {
+		$principalUri = $this->getPrincipalUri($user);
+		$calendarUri = $this->getUniqueCalendarUri($user, $initialCalendarUri);
+
+		$calendarId = $this->calDavBackend->createCalendar($principalUri, $calendarUri, [
+			'{DAV:}displayname' => isset($vCalendar->{'X-WR-CALNAME'}) ? $vCalendar->{'X-WR-CALNAME'}->getValue() : $this->l10n->t('Migrated calendar (%1$s)', [$filename]),
+			'{http://apple.com/ns/ical/}calendar-color' => isset($vCalendar->{'X-APPLE-CALENDAR-COLOR'}) ? $vCalendar->{'X-APPLE-CALENDAR-COLOR'}->getValue() : $this->defaults->getColorPrimary(),
+			'components' => implode(
+				',',
+				array_reduce(
+					$vCalendar->getComponents(),
+					function (array $componentNames, VObjectComponent $component) {
+						/** @var array<int, string> $componentNames */
+						return !in_array($component->name, $componentNames, true)
+							? [...$componentNames, $component->name]
+							: $componentNames;
+					},
+					[],
+				)
+			),
+		]);
+
+		/** @var VObjectComponent[] $calendarComponents */
+		$calendarComponents = array_values(array_filter(
+			$vCalendar->getComponents(),
+			// VTIMEZONE components are handled separately and added to the calendar object only if depended on by the component
+			fn (VObjectComponent $component) => $component->name !== 'VTIMEZONE',
+		));
+
+		/** @var array<string, VObjectComponent[]> $groupedCalendarComponents */
+		$groupedCalendarComponents = [];
+		/** @var VObjectComponent[] $ungroupedCalendarComponents */
+		$ungroupedCalendarComponents = [];
+
+		foreach ($calendarComponents as $component) {
+			if (isset($component->UID)) {
+				$uid = $component->UID->getValue();
+				// Components with the same UID (e.g. recurring events) are grouped together into a single calendar object
+				if (isset($groupedCalendarComponents[$uid])) {
+					$groupedCalendarComponents[$uid][] = $component;
+				} else {
+					$groupedCalendarComponents[$uid] = [$component];
+				}
+			} else {
+				$ungroupedCalendarComponents[] = $component;
+			}
+		}
+
+		foreach ($groupedCalendarComponents as $uid => $components) {
+			// Construct and import a calendar object containing all components of a group
+			$vCalendarObject = $this->initCalendarObject();
+			foreach ($components as $component) {
+				foreach ($this->getRequiredImportComponents($vCalendar, $component) as $component) {
+					$vCalendarObject->add($component);
+				}
+			}
+			$this->importCalendarObject($calendarId, $vCalendarObject, $output);
+		}
+
+		foreach ($ungroupedCalendarComponents as $component) {
+			// Construct and import a calendar object for a single component
+			$vCalendarObject = $this->initCalendarObject();
+			foreach ($this->getRequiredImportComponents($vCalendar, $component) as $component) {
+				$vCalendarObject->add($component);
+			}
+			$this->importCalendarObject($calendarId, $vCalendarObject, $output);
+		}
+	}
+
+	/**
+	 * {@inheritDoc}
+	 *
+	 * @throws CalendarMigratorException
+	 */
+	public function import(IUser $user, IImportSource $importSource, OutputInterface $output): void {
+		if ($importSource->getMigratorVersion(static::class) === null) {
+			$output->writeln('No version for ' . static::class . ', skipping import…');
+			return;
+		}
+
+		$output->writeln('Importing calendars from ' . CalendarMigrator::EXPORT_ROOT . '…');
+
+		$calendarImports = $importSource->getFolderListing(CalendarMigrator::EXPORT_ROOT);
+		if (empty($calendarImports)) {
+			$output->writeln('No calendars to import…');
+		}
+
+		foreach ($calendarImports as $filename) {
+			$importPath = CalendarMigrator::EXPORT_ROOT . $filename;
+			try {
+				/** @var VCalendar $vCalendar */
+				$vCalendar = VObjectReader::read(
+					$importSource->getFileAsStream($importPath),
+					VObjectReader::OPTION_FORGIVING,
+				);
+			} catch (Throwable $e) {
+				throw new CalendarMigratorException("Failed to read file \"$importPath\"", 0, $e);
+			}
+
+			$problems = $vCalendar->validate();
+			if (!empty($problems)) {
+				throw new CalendarMigratorException("Invalid calendar data contained in \"$importPath\"");
+			}
+
+			$splitFilename = explode('_', $filename, 2);
+			if (count($splitFilename) !== 2) {
+				throw new CalendarMigratorException("Invalid filename \"$filename\", expected filename of the format \"<calendar_name>_YYYY-MM-DD" . CalendarMigrator::FILENAME_EXT . '"');
+			}
+			[$initialCalendarUri, $suffix] = $splitFilename;
+
+			$this->importCalendar(
+				$user,
+				$filename,
+				$initialCalendarUri,
+				$vCalendar,
+				$output,
+			);
+
+			$vCalendar->destroy();
+		}
+	}
+}