<?php

declare(strict_types=1);
/**
 * @copyright Copyright (c) 2023 Robin Appelman <robin@icewind.nl>
 *
 * @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\Files\Command\Object;

use OC\Core\Command\Base;
use OCP\DB\QueryBuilder\IQueryBuilder;
use OCP\Files\ObjectStore\IObjectStore;
use OCP\IConfig;
use OCP\IDBConnection;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

class ObjectUtil extends Base {
	private IConfig $config;
	private IDBConnection $connection;

	public function __construct(IConfig $config, IDBConnection $connection) {
		$this->config = $config;
		$this->connection = $connection;
	}

	private function getObjectStoreConfig(): ?array {
		$config = $this->config->getSystemValue('objectstore_multibucket');
		if (is_array($config)) {
			$config['multibucket'] = true;
			return $config;
		}
		$config = $this->config->getSystemValue('objectstore');
		if (is_array($config)) {
			if (!isset($config['multibucket'])) {
				$config['multibucket'] = false;
			}
			return $config;
		} else {
			return null;
		}
	}

	public function getObjectStore(?string $bucket, OutputInterface $output): ?IObjectStore {
		$config = $this->getObjectStoreConfig();
		if (!$config) {
			$output->writeln("<error>Instance is not using primary object store</error>");
			return null;
		}
		if ($config['multibucket'] && !$bucket) {
			$output->writeln("<error>--bucket option required</error> because <info>multi bucket</info> is enabled.");
			return null;
		}

		if (!isset($config['arguments'])) {
			throw new \Exception("no arguments configured for object store configuration");
		}
		if (!isset($config['class'])) {
			throw new \Exception("no class configured for object store configuration");
		}

		if ($bucket) {
			// s3, swift
			$config['arguments']['bucket'] = $bucket;
			// azure
			$config['arguments']['container'] = $bucket;
		}

		$store = new $config['class']($config['arguments']);
		if (!$store instanceof IObjectStore) {
			throw new \Exception("configured object store class is not an object store implementation");
		}
		return $store;
	}

	/**
	 * Check if an object is referenced in the database
	 */
	public function objectExistsInDb(string $object): int|false {
		if (str_starts_with($object, 'urn:oid:')) {
			$fileId = (int)substr($object, strlen('urn:oid:'));
			$query = $this->connection->getQueryBuilder();
			$query->select('fileid')
				->from('filecache')
				->where($query->expr()->eq('fileid', $query->createNamedParameter($fileId, IQueryBuilder::PARAM_INT)));
			$result = $query->executeQuery();
			if ($result->fetchOne() !== false) {
				return $fileId;
			} else {
				return false;
			}
		} else {
			return false;
		}
	}

	public function writeIteratorToOutput(InputInterface $input, OutputInterface $output, \Iterator $objects, int $chunkSize): void {
		$outputType = $input->getOption('output');
		$humanOutput = $outputType === Base::OUTPUT_FORMAT_PLAIN;
		$first = true;

		if (!$humanOutput) {
			$output->writeln('[');
		}

		foreach ($this->chunkIterator($objects, $chunkSize) as $chunk) {
			if ($outputType === Base::OUTPUT_FORMAT_PLAIN) {
				$this->outputChunk($input, $output, $chunk);
			} else {
				foreach ($chunk as $object) {
					if (!$first) {
						$output->writeln(',');
					}
					$row = $this->formatObject($object, $humanOutput);
					if ($outputType === Base::OUTPUT_FORMAT_JSON_PRETTY) {
						$output->write(json_encode($row, JSON_PRETTY_PRINT));
					} else {
						$output->write(json_encode($row));
					}
					$first = false;
				}
			}
		}

		if (!$humanOutput) {
			$output->writeln("\n]");
		}
	}

	private function formatObject(array $object, bool $humanOutput): array {
		$row = array_merge([
			'urn' => $object['urn'],
		], ($object['metadata'] ?? []));

		if ($humanOutput && isset($row['size'])) {
			$row['size'] = \OC_Helper::humanFileSize($row['size']);
		}
		if (isset($row['mtime'])) {
			$row['mtime'] = $row['mtime']->format(\DateTimeImmutable::ATOM);
		}
		return $row;
	}

	private function outputChunk(InputInterface $input, OutputInterface $output, iterable $chunk): void {
		$result = [];
		$humanOutput = $input->getOption('output') === 'plain';

		foreach ($chunk as $object) {
			$result[] = $this->formatObject($object, $humanOutput);
		}
		$this->writeTableInOutputFormat($input, $output, $result);
	}

	public function chunkIterator(\Iterator $iterator, int $count): \Iterator {
		$chunk = [];

		for ($i = 0; $iterator->valid(); $i++) {
			$chunk[] = $iterator->current();
			$iterator->next();
			if (count($chunk) == $count) {
				yield $chunk;
				$chunk = [];
			}
		}

		if (count($chunk)) {
			yield $chunk;
		}
	}
}