owncloud/core

<?php
/**
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @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 OCA\DAV\SystemTag;

use OCP\IGroupManager;
use OCP\IUserSession;
use OCP\SystemTag\ISystemTag;
use OCP\SystemTag\ISystemTagManager;
use OCP\SystemTag\TagNotFoundException;
use Sabre\DAV\Exception\BadRequest;
use Sabre\DAV\Exception\Forbidden;
use Sabre\DAV\Exception\NotFound;
use Sabre\DAV\ICollection;

class SystemTagsByIdCollection implements ICollection {
    /**
     * @var ISystemTagManager
     */
    private $tagManager;

    /**
     * @var IGroupManager
     */
    private $groupManager;

    /**
     * @var IUserSession
     */
    private $userSession;

    /**
     * SystemTagsByIdCollection constructor.
     *
     * @param ISystemTagManager $tagManager
     * @param IUserSession $userSession
     * @param IGroupManager $groupManager
     */
    public function __construct(
        ISystemTagManager $tagManager,
        IUserSession $userSession,
        IGroupManager $groupManager
    ) {
        $this->tagManager = $tagManager;
        $this->userSession = $userSession;
        $this->groupManager = $groupManager;
    }

    /**
     * Returns whether the currently logged in user is an administrator
     *
     * @return bool true if the user is an admin
     */
    private function isAdmin() {
        $user = $this->userSession->getUser();
        if ($user !== null) {
            return $this->groupManager->isAdmin($user->getUID());
        }
        return false;
    }

    /**
     * @param string $name
     * @param resource|string $data Initial payload
     * @throws Forbidden
     */
    public function createFile($name, $data = null) {
        throw new Forbidden('Cannot create tags by id');
    }

    /**
     * @param string $name
     */
    public function createDirectory($name) {
        throw new Forbidden('Permission denied to create collections');
    }

    /**
     * @param string $name
     */
    public function getChild($name) {
        try {
            $tag = $this->tagManager->getTagsByIds([$name]);
            $tag = \current($tag);
            if (!$this->tagManager->canUserSeeTag($tag, $this->userSession->getUser())) {
                throw new NotFound('Tag with id ' . $name . ' not found');
            }
            return $this->makeNode($tag);
        } catch (\InvalidArgumentException $e) {
            throw new BadRequest('Invalid tag id', 0, $e);
        } catch (TagNotFoundException $e) {
            throw new NotFound('Tag with id ' . $name . ' not found', 0, $e);
        }
    }

    public function getChildren() {
        $visibilityFilter = true;
        if ($this->isAdmin()) {
            $visibilityFilter = null;
        }

        $tags = $this->tagManager->getAllTags($visibilityFilter, null);
        /**
         * Filter out static tags if the user does not have privilege to see it.
         */
        $tags =  \array_filter($tags, function ($tag) {
            if (!$tag->isUserEditable() && $tag->isUserAssignable()) {
                $user = $this->userSession->getUser();
                if (($user !== null) &&
                    !$this->tagManager->canUserUseStaticTagInGroup($tag, $user)) {
                    return false;
                }
            }
            return true;
        });

        return \array_map(function ($tag) {
            return $this->makeNode($tag);
        }, $tags);
    }

    /**
     * @param string $name
     */
    public function childExists($name) {
        try {
            $tag = $this->tagManager->getTagsByIds([$name]);
            $tag = \current($tag);
            if (!$this->tagManager->canUserSeeTag($tag, $this->userSession->getUser())) {
                return false;
            }
            return true;
        } catch (\InvalidArgumentException $e) {
            throw new BadRequest('Invalid tag id', 0, $e);
        } catch (TagNotFoundException $e) {
            return false;
        }
    }

    public function delete() {
        throw new Forbidden('Permission denied to delete this collection');
    }

    public function getName() {
        return 'systemtags';
    }

    public function setName($name) {
        throw new Forbidden('Permission denied to rename this collection');
    }

    /**
     * Returns the last modification time, as a unix timestamp
     *
     * @return int
     */
    public function getLastModified() {
        return null;
    }

    /**
     * Create a sabre node for the given system tag
     *
     * @param ISystemTag $tag
     *
     * @return SystemTagNode
     */
    private function makeNode(ISystemTag $tag) {
        return new SystemTagNode($tag, $this->userSession->getUser(), $this->isAdmin(), $this->tagManager);
    }
}