<?php

declare(strict_types=1);
/**
 * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
 * SPDX-License-Identifier: AGPL-3.0-or-later
 */

namespace OCA\Files_Sharing\Repair;

use OC\Files\SetupManager;
use OCA\Files_Sharing\ShareTargetValidator;
use OCP\DB\QueryBuilder\IQueryBuilder;
use OCP\Files\Config\ICachedMountInfo;
use OCP\Files\Config\IUserMountCache;
use OCP\Files\IRootFolder;
use OCP\Files\NotFoundException;
use OCP\ICacheFactory;
use OCP\IDBConnection;
use OCP\IUser;
use OCP\IUserManager;
use OCP\Migration\IOutput;
use OCP\Migration\IRepairStep;
use OCP\Share\IShare;
use Psr\Log\LoggerInterface;

/**
 * @psalm-type ShareInfo = array{id: string|int, share_type: string, share_with: string, file_source: string, file_target: string}
 */
class CleanupShareTarget implements IRepairStep {
	/** we only care about shares with a user target,
	 *  since the underling group/deck/talk share doesn't get moved
	 */
	private const USER_SHARE_TYPES = [
		IShare::TYPE_USER,
		IShare::TYPE_USERGROUP,
		IShare::TYPE_DECK_USER,
		11 // TYPE_USERROOM
	];

	public function __construct(
		private readonly IDBConnection $connection,
		private readonly ShareTargetValidator $shareTargetValidator,
		private readonly IUserManager $userManager,
		private readonly SetupManager $setupManager,
		private readonly IUserMountCache $userMountCache,
		private readonly IRootFolder $rootFolder,
		private readonly LoggerInterface $logger,
		private readonly ICacheFactory $cacheFactory,
	) {
	}

	#[\Override]
	public function getName() {
		return 'Cleanup share names with false conflicts';
	}

	#[\Override]
	public function run(IOutput $output) {
		$count = $this->countProblemShares();
		if ($count === 0) {
			return;
		}
		$output->startProgress($count);

		$lastUser = '';
		$userMounts = [];
		$userFolder = null;

		foreach ($this->getProblemShares() as $shareInfo) {
			if ($shareInfo['share_type'] === IShare::TYPE_CIRCLE) {
				$recipient = $this->getCircleShareOwner($shareInfo['share_with']);
				if ($recipient === null) {
					continue;
				}
			} else {
				$recipient = $this->userManager->getExistingUser($shareInfo['share_with']);
			}
			if (!$recipient->isEnabled()) {
				continue;
			}

			// since we ordered the share by user, we can reuse the last data until we get to the next user
			if ($lastUser !== $recipient->getUID()) {
				$lastUser = $recipient->getUID();

				$this->setupManager->tearDown();
				$this->setupManager->setupForUser($recipient);
				$mounts = $this->userMountCache->getMountsForUser($recipient);
				$mountPoints = array_map(fn (ICachedMountInfo $mount) => $mount->getMountPoint(), $mounts);
				$userMounts = array_combine($mountPoints, $mounts);
				$userFolder = $this->rootFolder->getUserFolder($recipient->getUID());
			}

			$oldTarget = $shareInfo['file_target'];
			$newTarget = $this->cleanTarget($oldTarget);
			$absoluteNewTarget = $userFolder->getFullPath($newTarget);
			try {
				$targetParentNode = $this->rootFolder->get(dirname($absoluteNewTarget));
			} catch (NotFoundException) {
				$absoluteNewTarget = $userFolder->getFullPath(basename($newTarget));
				$targetParentNode = $userFolder;
			}

			try {
				$absoluteNewTarget = $this->shareTargetValidator->generateUniqueTarget(
					(int)$shareInfo['file_source'],
					$absoluteNewTarget,
					$targetParentNode->getMountPoint(),
					$userMounts,
				);
				$newTarget = $userFolder->getRelativePath($absoluteNewTarget);

				$this->moveShare((string)$shareInfo['id'], $newTarget);

				$oldMountPoint = "/{$recipient->getUID()}/files$oldTarget/";
				$newMountPoint = "/{$recipient->getUID()}/files$newTarget/";
				$userMounts[$newMountPoint] = $userMounts[$oldMountPoint];
				unset($userMounts[$oldMountPoint]);
			} catch (\Exception $e) {
				$msg = 'error cleaning up share target: ' . $e->getMessage();
				$this->logger->error($msg, ['exception' => $e, 'app' => 'files_sharing']);
				$output->warning($msg);
			}

			$output->advance();
		}
		$this->cacheFactory->createDistributed('circles/')->clear();
		$output->finishProgress();
		$output->info("Fixed $count shares");
	}

	private function countProblemShares(): int {
		$query = $this->connection->getQueryBuilder();
		$query->select($query->func()->count('id'))
			->from('share')
			->where($query->expr()->like('file_target', $query->createNamedParameter('% (_) (_)%')))
			->andWhere($query->expr()->in('share_type', $query->createNamedParameter(self::USER_SHARE_TYPES, IQueryBuilder::PARAM_INT_ARRAY), IQueryBuilder::PARAM_INT_ARRAY));
		return (int)$query->executeQuery()->fetchOne();
	}

	private function moveShare(string $id, string $target): void {
		// since we only process user-specific shares, we can just move them
		// without having to check if we need to create a user-specific override
		$query = $this->connection->getQueryBuilder();
		$query->update('share')
			->set('file_target', $query->createNamedParameter($target))
			->where($query->expr()->eq('id', $query->createNamedParameter($id)))
			->executeStatement();
	}

	/**
	 * @return \Traversable<ShareInfo>
	 */
	private function getProblemShares(): \Traversable {
		$query = $this->connection->getQueryBuilder();
		$query->select('id', 'share_type', 'share_with', 'file_source', 'file_target')
			->from('share')
			->where($query->expr()->like('file_target', $query->createNamedParameter('% (_) (_)%')))
			->andWhere($query->expr()->orX(
				$query->expr()->in('share_type', $query->createNamedParameter(self::USER_SHARE_TYPES, IQueryBuilder::PARAM_INT_ARRAY), IQueryBuilder::PARAM_INT_ARRAY),
				$query->expr()->andX(
					$query->expr()->eq('share_type', $query->createNamedParameter(
						IShare::TYPE_CIRCLE, IQueryBuilder::PARAM_INT), IQueryBuilder::PARAM_INT),
					$query->expr()->isNotNull('parent'),
				),
			))
			->orderBy('share_with')
			->addOrderBy('id');
		$result = $query->executeQuery();
		/** @var \Traversable<ShareInfo> $rows */
		$rows = $result->iterateAssociative();
		return $rows;
	}

	private function cleanTarget(string $target): string {
		return preg_replace('/( \([2-9]\)){2,}/', '', $target);
	}

	/**
	 * Get the user of a federated user from circles, if the circle id belong to a user
	 */
	private function getCircleShareOwner(string $circleId): ?IUser {
		$query = $this->connection->getQueryBuilder();
		$query->select('name')
			->from('circles_circle')
			->where($query->expr()->eq('unique_id', $query->createNamedParameter($circleId)))
			->andWhere($query->expr()->eq('source', $query->createNamedParameter(1, IQueryBuilder::PARAM_INT)));
		$name = $query->executeQuery()->fetchOne();
		if ($name === false) {
			return null;
		}
		[$type, $userId,] = explode(':', $name, 3);
		if ($type === 'user') {
			return $this->userManager->getExistingUser($userId);
		} else {
			return null;
		}
	}
}