<?php
/**
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Robin McCorkell <robin@mccorkell.me.uk>
 * @author Stefan Weil <sw@weilnetz.de>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @copyright Copyright (c) 2018, ownCloud GmbH
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * 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, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC\Files\External\Service;

use OC\Files\Filesystem;

use OCP\Files\Config\IUserMountCache;
use OCP\IUser;
use OCP\IUserSession;

use OCP\Files\External\IStorageConfig;
use OCP\Files\External\NotFoundException;
use OCP\Files\External\IStoragesBackendService;
use OCP\Files\External\Service\IUserStoragesService;

/**
 * Service class to manage user external storages
 * (aka personal storages)
 */
class UserStoragesService extends StoragesService implements IUserStoragesService {
	use UserTrait;

	/**
	 * Create a user storages service
	 *
	 * @param IStoragesBackendService $backendService
	 * @param DBConfigService $dbConfig
	 * @param IUserSession $userSession user session
	 * @param IUserMountCache $userMountCache
	 */
	public function __construct(
		IStoragesBackendService $backendService,
		DBConfigService $dbConfig,
		IUserSession $userSession,
		IUserMountCache $userMountCache
	) {
		$this->userSession = $userSession;
		$this->userMountCache = $userMountCache;
		parent::__construct($backendService, $dbConfig, $userMountCache);
	}

	protected function readDBConfig() {
		return $this->dbConfig->getUserMountsFor(DBConfigService::APPLICABLE_TYPE_USER, $this->getUser()->getUID());
	}

	/**
	 * Triggers $signal for all applicable users of the given
	 * storage
	 *
	 * @param IStorageConfig $storage storage data
	 * @param string $signal signal to trigger
	 */
	protected function triggerHooks(IStorageConfig $storage, $signal) {
		$user = $this->getUser()->getUID();

		// trigger hook for the current user
		$this->triggerApplicableHooks(
			$signal,
			$storage->getMountPoint(),
			IStorageConfig::MOUNT_TYPE_USER,
			[$user]
		);
	}

	/**
	 * Triggers signal_create_mount or signal_delete_mount to
	 * accommodate for additions/deletions in applicableUsers
	 * and applicableGroups fields.
	 *
	 * @param IStorageConfig $oldStorage old storage data
	 * @param IStorageConfig $newStorage new storage data
	 */
	protected function triggerChangeHooks(IStorageConfig $oldStorage, IStorageConfig $newStorage) {
		// if mount point changed, it's like a deletion + creation
		if ($oldStorage->getMountPoint() !== $newStorage->getMountPoint()) {
			$this->triggerHooks($oldStorage, Filesystem::signal_delete_mount);
			$this->triggerHooks($newStorage, Filesystem::signal_create_mount);
		}
	}

	protected function getType() {
		return DBConfigService::MOUNT_TYPE_PERSONAl;
	}

	/**
	 * Add new storage to the configuration
	 *
	 * @param IStorageConfig $newStorage storage attributes
	 *
	 * @return IStorageConfig storage config, with added id
	 */
	public function addStorage(IStorageConfig $newStorage) {
		$newStorage->setApplicableUsers([$this->getUser()->getUID()]);
		$config = parent::addStorage($newStorage);
		return $config;
	}

	/**
	 * Update storage to the configuration
	 *
	 * @param IStorageConfig $updatedStorage storage attributes
	 *
	 * @return IStorageConfig storage config
	 * @throws NotFoundException if the given storage does not exist in the config
	 */
	public function updateStorage(IStorageConfig $updatedStorage) {
		$updatedStorage->setApplicableUsers([$this->getUser()->getUID()]);
		return parent::updateStorage($updatedStorage);
	}

	/**
	 * Get the visibility type for this controller, used in validation
	 *
	 * @return string IStoragesBackendService::VISIBILITY_* constants
	 */
	public function getVisibilityType() {
		return IStoragesBackendService::VISIBILITY_PERSONAL;
	}

	protected function isApplicable(IStorageConfig $config) {
		return ($config->getApplicableUsers() === [$this->getUser()->getUID()]) && $config->getType() === IStorageConfig::MOUNT_TYPE_PERSONAl;
	}

	/**
	 * Deletes the storages mounted to a user
	 * @param IUser $user
	 * @return bool
	 */
	public function deleteAllMountsForUser(IUser $user) {
		$getUserMounts = $this->userMountCache->getMountsForUser($user);
		$allMounts = $this->dbConfig->getAllMounts();
		$result = false;
		if (\count($getUserMounts) > 0) {
			foreach ($getUserMounts as $userMount) {
				$id = $userMount->getStorageId();
				$this->userMountCache->removeUserStorageMount($id, $user->getUID());
				$result = true;
			}
		}
		if (\count($allMounts)) {
			foreach ($allMounts as $userMount) {
				/**
				 * Remove any mounts which are applicable to only this user
				 * Specifically targeted to, mounts created by the user.
				 */
				if (\count($userMount['applicable']) === 1) {
					foreach ($userMount['applicable'] as $applicableUser) {
						if ($applicableUser['value'] === $user->getUID()) {
							$this->dbConfig->removeMount($applicableUser['mount_id']);
						}
					}
				}
			}
		}
		return $result;
	}
}
