<?php

declare(strict_types=1);
/**
 * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */
namespace OCA\DAV\Command;

use InvalidArgumentException;
use OCA\DAV\CalDAV\Export\ExportService;
use OCP\Calendar\CalendarExportOptions;
use OCP\Calendar\ICalendarExport;
use OCP\Calendar\IManager;
use OCP\IUserManager;
use Symfony\Component\Console\Attribute\AsCommand;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputArgument;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Input\InputOption;
use Symfony\Component\Console\Output\OutputInterface;

/**
 * Calendar Export Command
 *
 * Used to export data from supported calendars to disk or stdout
 */
#[AsCommand(
	name: 'calendar:export',
	description: 'Export calendar data from supported calendars to disk or stdout',
	hidden: false
)]
class ExportCalendar extends Command {
	public function __construct(
		private IUserManager $userManager,
		private IManager $calendarManager,
		private ExportService $exportService,
	) {
		parent::__construct();
	}

	protected function configure(): void {
		$this->setName('calendar:export')
			->setDescription('Export calendar data from supported calendars to disk or stdout')
			->addArgument('uid', InputArgument::REQUIRED, 'Id of system user')
			->addArgument('uri', InputArgument::REQUIRED, 'Uri of calendar')
			->addOption('format', null, InputOption::VALUE_REQUIRED, 'Format of output (ical, jcal, xcal) defaults to ical', 'ical')
			->addOption('location', null, InputOption::VALUE_REQUIRED, 'Location of where to write the output. defaults to stdout');
	}

	protected function execute(InputInterface $input, OutputInterface $output): int {
		$userId = $input->getArgument('uid');
		$calendarId = $input->getArgument('uri');
		$format = $input->getOption('format');
		$location = $input->getOption('location');

		if (!$this->userManager->userExists($userId)) {
			throw new InvalidArgumentException("User <$userId> not found.");
		}
		// retrieve calendar and evaluate if export is supported
		$calendars = $this->calendarManager->getCalendarsForPrincipal('principals/users/' . $userId, [$calendarId]);
		if ($calendars === []) {
			throw new InvalidArgumentException("Calendar <$calendarId> not found.");
		}
		$calendar = $calendars[0];
		if (!$calendar instanceof ICalendarExport) {
			throw new InvalidArgumentException("Calendar <$calendarId> does not support exporting");
		}
		// construct options object
		$options = new CalendarExportOptions();
		// evaluate if provided format is supported
		if (!in_array($format, ExportService::FORMATS, true)) {
			throw new InvalidArgumentException("Format <$format> is not valid.");
		}
		$options->setFormat($format);
		// evaluate is a valid location was given and is usable otherwise output to stdout
		if ($location !== null) {
			$handle = fopen($location, 'wb');
			if ($handle === false) {
				throw new InvalidArgumentException("Location <$location> is not valid. Can not open location for write operation.");
			}
			
			foreach ($this->exportService->export($calendar, $options) as $chunk) {
				fwrite($handle, $chunk);
			}
			fclose($handle);
		} else {
			foreach ($this->exportService->export($calendar, $options) as $chunk) {
				$output->writeln($chunk);
			}
		}

		return self::SUCCESS;
	}
}