Implement new user back end API

This API uses single-method interfaces, an abstract base class for user
back ends and exceptions.

 Signed-off-by: Alexey Abel <dev@abelonline.de>

lib/private/User/Backend.php

@@ -29,6 +29,7 @@ use OCP\UserInterface;
 /**
  * Abstract base class for user management. Provides methods for querying backend
  * capabilities.
+ * @deprecated 21.0.0 use \OCP\Public\User\Backend\AbstractUserBackEnd instead
  */
 abstract class Backend implements UserInterface {
 	/**

lib/public/IUserBackend.php

@@ -36,6 +36,7 @@ namespace OCP;
  * Interface IUserBackend
  *
  * @since 8.0.0
+ * @deprecated 21.0.0 use \OCP\Public\User\Backend\AbstractUserBackEnd instead
  */
 interface IUserBackend {
 
@@ -43,6 +44,7 @@ interface IUserBackend {
 	 * Backend name to be shown in user management
 	 * @return string the name of the backend to be shown
 	 * @since 8.0.0
+	 * @deprecated 21.0.0 use \OCP\Public\User\Backend\IUserBackEnd instead
 	 */
 	public function getBackendName();
 }

lib/public/User/Backend/ABackend.php

@@ -33,6 +33,7 @@ use OCP\UserInterface;
 
 /**
  * @since 14.0.0
+ * @deprecated 21.0.0 use \OCP\Public\User\Backend\AbstractUserBackEnd instead
  */
 abstract class ABackend implements IUserBackend, UserInterface {
 

lib/public/User/Backend/AbstractUserBackend.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend;
+
+/**
+ * Class AbstractUserBackend should be used as a base for all user back ends, e.g. implemented by apps.
+ * Additionally implement any number of interfaces in OCP\User\Backend\Action.
+ *
+ * @package OCP\User\Backend
+ * @since 21.0.0
+ */
+class AbstractUserBackend {
+
+	/** @var string */
+	private $backEndName;
+
+	public function __construct(string $backEndName) {
+		$this->backEndName = $backEndName;
+	}
+
+	public function getName(): string {
+		return $this->backEndName;
+	}
+}

lib/public/User/Backend/Action/ICheckPassword.php

@@ -0,0 +1,55 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface ICheckPassword {
+	/**
+	 * @return bool whether the implementing user back end has the ability to check a password at this time
+	 * or with the current configuration
+	 */
+	public function canCheckPassword() : bool;
+
+	/**
+	 * Returns whether the supplied password is correct for the supplied user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username of the checked user
+	 * @param string $password the password of the user to check
+	 * @return bool true if password is correct, false otherwise
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function checkPassword(string $username, string $password): bool;
+}

lib/public/User/Backend/Action/ICountUsers.php

@@ -0,0 +1,51 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface ICountUsers {
+	/**
+	 * @return bool whether the implementing user back end has the ability to count users at this time
+	 * or with the current configuration
+	 */
+	public function canCountUsers() : bool;
+
+	/**
+	 * Returns the number of users present in this user backend.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @return int the number of users present in this user backend
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 */
+	public function countUsers(): int;
+}

lib/public/User/Backend/Action/ICreateUser.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserAlreadyExistsException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface ICreateUser {
+	/**
+	 * @return bool whether the implementing user back end has the ability to create a user at this time
+	 * or with the current configuration
+	 */
+	public function canCreateUser(): bool;
+
+	/**
+	 * Creates a new user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username of the new user
+	 * @param string $password the password of the new user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserAlreadyExistsException if a user with provided username already exists
+	 */
+	public function createUser(string $username, string $password): void;
+}

lib/public/User/Backend/Action/IDeleteUser.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IDeleteUser {
+	/**
+	 * @return bool whether the implementing user back end has the ability to create a user at this time
+	 * or with the current configuration
+	 */
+	public function canDeleteUser() : bool;
+
+	/**
+	 * Deletes a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username of the user to be deleted
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function deleteUser(string $username): void;
+}

lib/public/User/Backend/Action/IFindUsersByDisplayName.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IFindUsersByDisplayName {
+	/**
+	 * @return bool whether the implementing user back end has the ability to search users at this time
+	 * or with the current configuration
+	 */
+	public function canFindUsersByDisplayName() : bool;
+
+	/**
+	 * Finds users by display name and returns a list of matched users.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $pattern the search pattern
+	 * @param int $limit limit the returned users to only this many
+	 * @param int $offset start the returned users at this position, 0-based
+	 * @return iterable list of users that matched the pattern or empty iterable if none matched
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 */
+	public function findUsersByDisplayName(string $pattern, ?int $limit, ?int $offset): iterable;
+}

lib/public/User/Backend/Action/IFindUsersByUsername.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IFindUsersByUsername {
+	/**
+	 * @return bool whether the implementing user back end has the ability to search users at this time
+	 * or with the current configuration
+	 */
+	public function canFindUsersByUsername() : bool;
+
+	/**
+	 * Finds users by username and returns a list of matched users.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $pattern the search pattern
+	 * @param int $limit limit the returned users to only this many
+	 * @param int $offset start the returned users at this position, 0-based
+	 * @return iterable list of users that matched the pattern or empty iterable if none matched
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 */
+	public function findUsersByUsername(string $pattern, ?int $limit, ?int $offset): iterable;
+}

lib/public/User/Backend/Action/IGetDisplayName.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IGetDisplayName {
+	/**
+	 * @return bool whether the implementing user back end has the ability to get a display name at this time
+	 * or with the current configuration
+	 */
+	public function canGetDisplayName() : bool;
+
+	/**
+	 * Gets the display name for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to get the display name for
+	 * @return string the display name of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function getDisplayName(string $username): string;
+}

lib/public/User/Backend/Action/IGetEMail.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IGetEMail {
+	/**
+	 * @return bool whether the implementing user back end has the ability to get a e-mail at this time
+	 * or with the current configuration
+	 */
+	public function canGetEMail() : bool;
+
+	/**
+	 * Gets the e-mail address for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to get the e-mail for
+	 * @return string the e-mail of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function getEMail(string $username): string;
+}

lib/public/User/Backend/Action/IGetHome.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IGetHome {
+	/**
+	 * @return bool whether the implementing user back end has the ability to get a home folder at this time
+	 * or with the current configuration
+	 */
+	public function canGetHome() : bool;
+
+	/**
+	  * Gets the home folder for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to get the home folder for
+	 * @return string the home folder of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function getHome(string $username): string;
+}

lib/public/User/Backend/Action/IGetQuota.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IGetQuota {
+	/**
+	 * @return bool whether the implementing user back end has the ability to get a quota at this time
+	 * or with the current configuration
+	 */
+	public function canGetQuota() : bool;
+
+	/**
+	 * Gets the quota for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to get the quota for
+	 * @return string the quota of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function getQuota(string $username): string;
+}

lib/public/User/Backend/Action/IGetRealUid.php

@@ -0,0 +1,56 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IGetRealUid {
+	/**
+	 * @return bool whether the implementing user back end has the ability to get the real uid at this time
+	 * or with the current configuration
+	 */
+	public function canGetRealUid() : bool;
+
+	/**
+	 * Some back ends accept different UIDs than what is the internal UID to be used.
+	 * For example the database backend accepts different cased UIDs in all the functions
+	 * but the internal UID that is to be used should be correctly cased.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to get the real UID for
+	 * @return string the real UID of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function getRealUid(string $username): string;
+}

lib/public/User/Backend/Action/IHasUser.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface IHasUser {
+	/**
+	 * @return bool whether the implementing user back end has the ability to check whether a user exsits at
+	 * this time or with the current configuration
+	 */
+	public function canHasUser() : bool;
+
+	/**
+	 * Checks whether a user exists in this user back end.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username whose existence is checked
+	 * @return bool whether the user exists in this user back end
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 */
+	public function hasUser(string $username): bool;
+}

lib/public/User/Backend/Action/ISetDisplayName.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface ISetDisplayName {
+	/**
+	 * @return bool whether the implementing user back end has the ability to set a display name at this time
+	 * or with the current configuration
+	 */
+	public function canSetDisplayName() : bool;
+
+	/**
+	 * Sets a new display name for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to set the display name for
+	 * @param string $newDisplayName the new display name of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function setDisplayName(string $username, string $newDisplayName): void;
+}

lib/public/User/Backend/Action/ISetEMail.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface ISetEMail {
+	/**
+	 * @return bool whether the implementing user back end has the ability to set a e-mail at this time
+	 * or with the current configuration
+	 */
+	public function canSetEMail() : bool;
+
+	/**
+	 * Sets a new e-mail for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to set the e-mail for
+	 * @param string $newEMail the new e-mail of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function setEMail(string $username, string $newEMail): void;
+}

lib/public/User/Backend/Action/ISetHome.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface ISetHome {
+	/**
+	 * @return bool whether the implementing user back end has the ability to set a home folder at this time
+	 * or with the current configuration
+	 */
+	public function canSetHome() : bool;
+
+	/**
+	 * Sets a new home folder for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to set the home folder for
+	 * @param string $newHome the new home folder of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function setHome(string $username, string $newHome): void;
+}

lib/public/User/Backend/Action/ISetPassword.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface ISetPassword {
+	/**
+	 * @return bool whether the implementing user back end has the ability to set a password at this time
+	 * or with the current configuration
+	 */
+	public function canSetPassword() : bool;
+
+	/**
+	 * Sets a new password for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to set the password for
+	 * @param string $newPassword the new password of the user
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function setPassword(string $username, string $newPassword): void;
+}

lib/public/User/Backend/Action/ISetQuota.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2020, Alexey Abel <dev@abelonline.de>
+ *
+ * @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 OCP\User\Backend\Action;
+
+use OCP\User\Backend\Exception\ActionNotAvailableException;
+use OCP\User\Backend\Exception\UserDoesNotExistInBackEndException;
+
+
+/**
+ * @since 21.0.0
+ */
+interface ISetQuota {
+	/**
+	 * @return bool whether the implementing user back end has the ability to set a quota at this time
+	 * or with the current configuration
+	 */
+	public function canSetQuota() : bool;
+
+	/**
+	 * Sets a new quota for a user.
+	 *
+	 * Before using this method, you must call `can...Currently()` of this interface to ensure that the user
+	 * backend can perform this action at his time or with the current configuration, since this can change
+	 * during runtime. The implementing user back end will throw an ActionNotAvailableException if it doesn't.
+	 *
+	 * @param string $username the username to set the quota for
+	 * @param string $newQuota the new quota value
+	 * @throws ActionNotAvailableException if this action is not supported at this time
+	 * @throws UserDoesNotExistInBackEndException if specified username doesn't exist in the user back end
+	 */
+	public function setQuota(string $username, string $newQuota): void;
+}

lib/public/User/Backend/Exception/ActionNotAvailableException.php

@@ -0,0 +1,10 @@
+<?php
+
+
+namespace OCP\User\Backend\Exception;
+
+use RuntimeException;
+
+class ActionNotAvailableException extends RuntimeException {
+
+}

lib/public/User/Backend/Exception/UserAlreadyExistsException.php

@@ -0,0 +1,10 @@
+<?php
+
+
+namespace OCP\User\Backend\Exception;
+
+use RuntimeException;
+
+class UserAlreadyExistsException extends RuntimeException {
+
+}

lib/public/User/Backend/Exception/UserDoesNotExistInBackEndException.php

@@ -0,0 +1,10 @@
+<?php
+
+
+namespace OCP\User\Backend\Exception;
+
+use RuntimeException;
+
+class UserDoesNotExistInBackEndException extends RuntimeException {
+
+}

lib/public/User/Backend/ICheckPasswordBackend.php

@@ -29,10 +29,12 @@ namespace OCP\User\Backend;
 
 /**
  * @since 14.0.0
+ * @deprecated 21.0.0
  */
 interface ICheckPasswordBackend {
 	/**
 	 * @since 14.0.0
+	 * @deprecated 21.0.0
 	 *
 	 * @param string $loginName The loginname
 	 * @param string $password The password

lib/public/User/Backend/ICountUsersBackend.php

@@ -28,11 +28,13 @@ namespace OCP\User\Backend;
 
 /**
  * @since 14.0.0
+ * @deprecated 21.0.0
  */
 interface ICountUsersBackend {
 
 	/**
 	 * @since 14.0.0
+	 * @deprecated 21.0.0
 	 *
 	 * @return int|bool The number of users on success false on failure
 	 */

lib/public/User/Backend/ICreateUserBackend.php

@@ -28,11 +28,13 @@ namespace OCP\User\Backend;
 
 /**
  * @since 14.0.0
+ * @deprecated 21.0.0
  */
 interface ICreateUserBackend {
 
 	/**
 	 * @since 14.0.0
+	 * @deprecated 21.0.0
 	 *
 	 * @param string $uid The username of the user to create
 	 * @param string $password The password of the new user

lib/public/User/Backend/IGetDisplayNameBackend.php

@@ -28,11 +28,13 @@ namespace OCP\User\Backend;
 
 /**
  * @since 14.0.0
+ * @deprecated 21.0.0
  */
 interface IGetDisplayNameBackend {
 
 	/**
 	 * @since 14.0.0
+	 * @deprecated 21.0.0
 	 *
 	 * @param string $uid user ID of the user
 	 * @return string display name

lib/public/User/Backend/IGetHomeBackend.php

@@ -28,11 +28,13 @@ namespace OCP\User\Backend;
 
 /**
  * @since 14.0.0
+ * @deprecated  21.0.0
  */
 interface IGetHomeBackend {
 
 	/**
 	 * @since 14.0.0
+	 * @deprecated 21.0.0
 	 *
 	 * @param string $uid the username
 	 * @return string|bool Datadir on success false on failure

lib/public/User/Backend/IGetRealUIDBackend.php

@@ -28,6 +28,7 @@ namespace OCP\User\Backend;
 
 /**
  * @since 17.0.0
+ * @deprecated 21.0.0
  */
 interface IGetRealUIDBackend {
 
@@ -39,6 +40,7 @@ interface IGetRealUIDBackend {
 	 * This little function makes sure that the used UID will be correct hen using the user object
 	 *
 	 * @since 17.0.0
+	 * @deprecated 21.0.0
 	 * @param string $uid
 	 * @return string
 	 */

lib/public/User/Backend/IPasswordConfirmationBackend.php

@@ -28,11 +28,14 @@ namespace OCP\User\Backend;
 
 /**
  * @since 15.0.0
+ * @deprecated 21.0.0
  */
 interface IPasswordConfirmationBackend {
 
 	/**
 	 * @since 15.0.0
+	 * @deprecated 21.0.0 Use @see \OCP\User\Backend\Action\ICheckPassword::canCheckPasswordCurrently()
+	 * instead.
 	 */
 	public function canConfirmPassword(string $uid): bool;
 }

lib/public/User/Backend/ISetDisplayNameBackend.php

@@ -28,11 +28,13 @@ namespace OCP\User\Backend;
 
 /**
  * @since 14.0.0
+ * @deprecated 21.0.0
  */
 interface ISetDisplayNameBackend {
 
 	/**
 	 * @since 14.0.0
+	 * @deprecated 21.0.0
 	 *
 	 * @param string $uid The username
 	 * @param string $displayName The new display name

lib/public/User/Backend/ISetPasswordBackend.php

@@ -28,11 +28,13 @@ namespace OCP\User\Backend;
 
 /**
  * @since 14.0.0
+ * @deprecated 21.0.0 Use \OCP\User\Backend\Action\ISetPassword instead
  */
 interface ISetPasswordBackend {
 
 	/**
 	 * @since 14.0.0
+	 * @deprecated 21.0.0 Use \OCP\User\Backend\Action\ISetPassword::setPassword() instead
 	 *
 	 * @param string $uid The username
 	 * @param string $password The new password

lib/public/UserInterface.php

@@ -38,6 +38,7 @@ namespace OCP;
  * TODO actually this is a IUserBackend
  *
  * @since 4.5.0
+ * @deprecated 21.0.0 use \OCP\User\Backend\AbstractUserBackEnd instead
  */
 interface UserInterface {
 
@@ -49,7 +50,7 @@ interface UserInterface {
 	 * Returns the supported actions as int to be
 	 * compared with \OC\User\Backend::CREATE_USER etc.
 	 * @since 4.5.0
-	 * @deprecated 14.0.0 Switch to the interfaces from OCP\User\Backend
+	 * @deprecated 21.0.0 implement interfaces from \OCP\User\Backend\Action instead
 	 */
 	public function implementsActions($actions);
 
@@ -58,6 +59,7 @@ interface UserInterface {
 	 * @param string $uid The username of the user to delete
 	 * @return bool
 	 * @since 4.5.0
+	 * @deprecated 21.0.0 implement interfaces from \OCP\User\Backend\Action instead
 	 */
 	public function deleteUser($uid);
 
@@ -69,6 +71,7 @@ interface UserInterface {
 	 * @param null|int $offset
 	 * @return string[] an array of all uids
 	 * @since 4.5.0
+	 * @deprecated 21.0.0 implement interfaces from \OCP\User\Backend\Action instead
 	 */
 	public function getUsers($search = '', $limit = null, $offset = null);
 
@@ -77,6 +80,7 @@ interface UserInterface {
 	 * @param string $uid the username
 	 * @return boolean
 	 * @since 4.5.0
+	 * @deprecated 21.0.0 implement interfaces from \OCP\User\Backend\Action instead
 	 */
 	public function userExists($uid);
 
@@ -85,6 +89,7 @@ interface UserInterface {
 	 * @param string $uid user ID of the user
 	 * @return string display name
 	 * @since 4.5.0
+	 * @deprecated 21.0.0 implement interfaces from \OCP\User\Backend\Action instead
 	 */
 	public function getDisplayName($uid);
 
@@ -96,6 +101,7 @@ interface UserInterface {
 	 * @param string|null $offset
 	 * @return array an array of all displayNames (value) and the corresponding uids (key)
 	 * @since 4.5.0
+	 * @deprecated 21.0.0 implement interfaces from \OCP\User\Backend\Action instead
 	 */
 	public function getDisplayNames($search = '', $limit = null, $offset = null);
 
@@ -103,6 +109,7 @@ interface UserInterface {
 	 * Check if a user list is available or not
 	 * @return boolean if users can be listed or not
 	 * @since 4.5.0
+	 * @deprecated 21.0.0 implement interfaces from \OCP\User\Backend\Action instead
 	 */
 	public function hasUserListings();
 }