<?php

/**
 * ownCloud
 *
 * @author Frank Karlitschek
 * @copyright 2010 Frank Karlitschek karlitschek@kde.org
 *
 * 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/>.
 *
 */
/*
 *
 * The following SQL statement is just a help for developers and will not be
 * executed!
 *
 * CREATE TABLE `users` (
 *   `uid` varchar(64) COLLATE utf8_unicode_ci NOT NULL,
 *   `password` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
 *   PRIMARY KEY (`uid`)
 * ) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;
 *
 */

require_once('User/backend.php');

/**
 * Class for user management in a SQL Database (e.g. MySQL, SQLite)
 */
class OC_USER_DATABASE extends OC_USER_BACKEND {
	static private $userGroupCache=array();

	/**
	 * @brief Create a new user
	 * @param $username The username of the user to create
	 * @param $password The password of the new user
	 * @returns true/false
	 *
	 * Creates a new user
	 */
	public static function createUser( $username, $password ){
		// Check if the user already exists
		$query = OC_DB::prepare( "SELECT * FROM `*PREFIX*users` WHERE uid = ?" );
		$result = $query->execute( array( $username ));

		if ( $result->numRows() > 0 ){
			return false;
		}
		else{
			$query = OC_DB::prepare( "INSERT INTO `*PREFIX*users` ( `uid`, `password` ) VALUES( ?, ? )" );
			$result = $query->execute( array( $username, sha1( $password )));

			return $result ? true : false;
		}
	}

	/**
	 * @brief delete a user
	 * @param $uid The username of the user to delete
	 * @returns true/false
	 *
	 * Deletes a user
	 */
	public static function deleteUser( $uid ){
		// Delete user
		$query = OC_DB::prepare( "DELETE FROM `*PREFIX*users` WHERE uid = ?" );
		$result = $query->execute( array( $uid ));

		// Delete user-group-relation
		$query = OC_DB::prepare( "DELETE FROM `*PREFIX*group_user` WHERE uid = ?" );
		$result = $query->execute( array( $uid ));
		return true;
	}

	/**
	 * @brief Try to login a user
	 * @param $uid The username of the user to log in
	 * @param $password The password of the user
	 * @returns true/false
	 *
	 * Log in a user - if the password is ok
	 */
	public static function login( $uid, $password ){
		// Query
		$query = OC_DB::prepare( "SELECT uid FROM *PREFIX*users WHERE uid = ? AND password = ?" );
		$result = $query->execute( array( $uid, sha1( $password )));

		if( $result->numRows() > 0 ){
			// Set username if name and password are known
			$row = $result->fetchRow();
			$_SESSION['user_id'] = $row["uid"];
			OC_LOG::add( "core", $_SESSION['user_id'], "login" );
			return true;
		}
		else{
			return false;
		}
	}

	/**
	 * @brief Kick the user
	 * @returns true
	 *
	 * Logout, destroys session
	 */
	public static function logout(){
		OC_LOG::add( "core", $_SESSION['user_id'], "logout" );
		$_SESSION['user_id'] = false;

		return true;
	}

	/**
	 * @brief Check if the user is logged in
	 * @returns true/false
	 *
	 * Checks if the user is logged in
	 */
	public static function isLoggedIn() {
		if( isset($_SESSION['user_id']) AND $_SESSION['user_id'] ){
			return true;
		}
		else{
			return false;
		}
	}

	/**
	 * @brief Autogenerate a password
	 * @returns string
	 *
	 * generates a password
	 */
	public static function generatePassword(){
		return uniqId();
	}

	/**
	 * @brief Set password
	 * @param $uid The username
	 * @param $password The new password
	 * @returns true/false
	 *
	 * Change the password of a user
	 */
	public static function setPassword( $uid, $password ){
		// Check if the user already exists
		$query = OC_DB::prepare( "SELECT * FROM `*PREFIX*users` WHERE uid = ?" );
		$result = $query->execute( array( $uid ));

		if ( $result->numRows() > 0 ){
			return false;
		}
		else{
			$query = OC_DB::prepare( "UPDATE *PREFIX*users SET password = ? WHERE uid = ?" );
			$result = $query->execute( array( sha1( $password ), $uid ));

			return true;
		}
	}

	/**
	 * @brief Check if the password is correct
	 * @param $uid The username
	 * @param $password The password
	 * @returns true/false
	 *
	 * Check if the password is correct without logging in the user
	 */
	public static function checkPassword( $uid, $password ){
		$query = OC_DB::prepare( "SELECT uid FROM *PREFIX*users WHERE uid = ? AND password = ?" );
		$result = $query->execute( array( $uid, sha1( $password )));

		if( $result->numRows() > 0 ){
			return true;
		}
		else{
			return false;
		}
	}

	/**
	 * @brief Get a list of all users
	 * @returns array with all uids
	 *
	 * Get a list of all users.
	 */
	public static function getUsers(){
		$query = OC_DB::prepare( "SELECT uid FROM *PREFIX*users" );
		$result = $query->execute();

		$users=array();
		while( $row = $result->fetchRow()){
			$users[] = $row["uid"];
		}
		return $users;
	}
}