<?php
/**
 * ownCloud
 *
 * @author Bart Visscher
 * @copyright 2013 Bart Visscher bartv@thisnet.nl
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or any later version.
 *
 * This library 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 library.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

/**
 * Public interface of ownCloud for apps to use.
 * Config interface
 *
 */

// use OCP namespace for all classes that are considered public.
// This means that they should be used by apps instead of the internal ownCloud classes
namespace OCP;

/**
 * Access to all the configuration options ownCloud offers
 */
interface IConfig {
	/**
	 * Sets a new system wide value
	 *
	 * @param string $key the key of the value, under which will be saved
	 * @param mixed $value the value that should be stored
	 */
	public function setSystemValue($key, $value);

	/**
	 * Looks up a system wide defined value
	 *
	 * @param string $key the key of the value, under which it was saved
	 * @param mixed $default the default value to be returned if the value isn't set
	 * @return mixed the value or $default
	 */
	public function getSystemValue($key, $default = '');

	/**
	 * Delete a system wide defined value
	 *
	 * @param string $key the key of the value, under which it was saved
	 */
	public function deleteSystemValue($key);

	/**
	 * Get all keys stored for an app
	 *
	 * @param string $appName the appName that we stored the value under
	 * @return string[] the keys stored for the app
	 */
	public function getAppKeys($appName);

	/**
	 * Writes a new app wide value
	 *
	 * @param string $appName the appName that we want to store the value under
	 * @param string $key the key of the value, under which will be saved
	 * @param string $value the value that should be stored
	 * @return void
	 */
	public function setAppValue($appName, $key, $value);

	/**
	 * Looks up an app wide defined value
	 *
	 * @param string $appName the appName that we stored the value under
	 * @param string $key the key of the value, under which it was saved
	 * @param string $default the default value to be returned if the value isn't set
	 * @return string the saved value
	 */
	public function getAppValue($appName, $key, $default = '');

	/**
	 * Delete an app wide defined value
	 *
	 * @param string $appName the appName that we stored the value under
	 * @param string $key the key of the value, under which it was saved
	 */
	public function deleteAppValue($appName, $key);

	/**
	 * Removes all keys in appconfig belonging to the app
	 *
	 * @param string $appName the appName the configs are stored under
	 */
	public function deleteAppValues($appName);


	/**
	 * Set a user defined value
	 *
	 * @param string $userId the userId of the user that we want to store the value under
	 * @param string $appName the appName that we want to store the value under
	 * @param string $key the key under which the value is being stored
	 * @param string $value the value that you want to store
	 * @param string $preCondition only update if the config value was previously the value passed as $preCondition
	 * @throws \OCP\PreConditionNotMetException if a precondition is specified and is not met
	 */
	public function setUserValue($userId, $appName, $key, $value, $preCondition = null);

	/**
	 * Shortcut for getting a user defined value
	 *
	 * @param string $userId the userId of the user that we want to store the value under
	 * @param string $appName the appName that we stored the value under
	 * @param string $key the key under which the value is being stored
	 * @param string $default the default value to be returned if the value isn't set
	 * @return string
	 */
	public function getUserValue($userId, $appName, $key, $default = '');

	/**
	 * Fetches a mapped list of userId -> value, for a specified app and key and a list of user IDs.
	 *
	 * @param $appName app to get the value for
	 * @param $key the key to get the value for
	 * @param $userIds the user IDs to fetch the values for
	 * @return array Mapped values: userId => value
	 */
	public function getUserValueForUsers($appName, $key, $userIds);

	/**
	 * Get the keys of all stored by an app for the user
	 *
	 * @param string $userId the userId of the user that we want to store the value under
	 * @param string $appName the appName that we stored the value under
	 * @return string[]
	 */
	public function getUserKeys($userId, $appName);

	/**
	 * Delete a user value
	 *
	 * @param string $userId the userId of the user that we want to store the value under
	 * @param string $appName the appName that we stored the value under
	 * @param string $key the key under which the value is being stored
	 */
	public function deleteUserValue($userId, $appName, $key);

	/**
	 * Delete all user values
	 *
	 * @param string $userId the userId of the user that we want to remove all values from
	 */
	public function deleteAllUserValues($userId);

	/**
	 * Delete all user related values of one app
	 *
	 * @param string $appName the appName of the app that we want to remove all values from
	 */
	public function deleteAppFromAllUsers($appName);

	/**
	 * Determines the users that have the given value set for a specific app-key-pair
	 *
	 * @param string $appName the app to get the user for
	 * @param string $key the key to get the user for
	 * @param string $value the value to get the user for
	 * @return array of user IDs
	 */
	public function getUsersForUserValue($appName, $key, $value);
}