<?php
/*!
 * OS.js - JavaScript Operating System
 *
 * Mysql Handler: Login screen and session/settings handling via database
 * PLEASE NOTE THAT THIS AN EXAMPLE ONLY, AND SHOUD BE MODIFIED BEFORE USAGE
 *
 * Copyright (c) 2011-2016, Anders Evenrud <andersevenrud@gmail.com>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author  Anders Evenrud <andersevenrud@gmail.com>
 * @licence Simplified BSD License
 */

/*
See doc/example-handler.txt
*/

define("APIHANDLER_DSN", "mysql:host=localhost;dbname=osjs");
define("APIHANDLER_USER", "osjs");
define("APIHANDLER_PASS", "osjs");
define("PASSWORD_BCRYPT", true);

/**
 * MysqlAPIHandler for sessions via database
 */
class MysqlAPIHandler
{
  /**
   * Create the database connection
   * @return PDO
   * @throws Exception
   */
  protected static function _initDB() {
    $args = [1002 => "SET NAMES 'utf8'"];

    if ( !($db = new PDO(APIHANDLER_DSN, APIHANDLER_USER, APIHANDLER_PASS, $args)) ) {
      throw new Exception("Could not set up database connection");
    }

    $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    return $db;
  }

  /**
   * This login an user
   *
   * @param array $arguments
   * @return array
   * @throws Exception
   */
  public static function login(array $arguments) {
    $db = self::_initDB();

    unset($_SESSION['user']);

    self::checkPassword($arguments['username'], $arguments['password']);

    $q = "SELECT `id`, `username`, `name`, `groups`, `settings` FROM `users` WHERE `username` = ? LIMIT 1;";
    $a = [$arguments['username']];

    $response = false;
    if ( $stmt = $db->prepare($q) ) {
      $stmt->setFetchMode(PDO::FETCH_ASSOC);
      if ( $stmt->execute($a) ) {
        if ( $row = $stmt->fetch() ) {

          $response = [
            "userData" => [
              "id" => (int)$row['id'],
              "username" => $row['username'],
              "name" => $row['name'],
              "groups" => (array)json_decode($row['groups'])
            ],
            "userSettings" => (array)json_decode($row['settings'])
          ];

          if ( !$response['userData']['groups'] ) {
            $response['userData']['groups'] = [];
          }
          if ( !$response['userSettings'] ) {
            $response['userSettings'] = null;
          }
        }
      }
    }

    if ( $response ) {
      $settings = Settings::get();
      $user = APIUser::login($response["userData"]);

      $homedir = sprintf("%s/%s", $settings['vfs']['homes'], $user->getUsername());
      if ( !file_exists($homedir) ) {
        @mkdir($homedir);
        @mkdir("{$homedir}/.packages");
      }
    }

    return [false, $response];
  }

  /**
   * This logout the authenticated user
   *
   * @param array $arguments
   * @return array
   * @throws Exception
   */
  public static function logout(array $arguments) {
    $db = self::_initDB();

    APIUser::logout();

    return [false, true];
  }

  /**
   * This updates the settings of the authenticated user
   *
   * @param array $arguments
   * @return array
   * @throws Exception
   */
  public static function settings(array $arguments) {
    $db = self::_initDB();

    $result = false;

    if ( !isset($_SESSION['user']) ) {
      throw new Exception("Cannot set settings without user session");
    }

    $q = "UPDATE `users` SET `settings` = ? WHERE `id` = ?;";
    $a = [json_encode($arguments['settings']), $_SESSION['user']['id']];

    if ( $stmt = $db->prepare($q) ) {
      $result = $stmt->execute($a);
    }

    return [false, $result];
  }

  /**
   * This checks the password for a given username
   *
   * @param $username
   * @param $password
   * @return bool
   * @throws Exception
   */
  public static function checkPassword($username, $password) {
    $db = self::_initDB();

    $q = "SELECT `password` FROM `osjs_users` WHERE `username` = ? LIMIT 1;";
    $a = [$username];

    if ( $stmt = $db->prepare($q) ) {
      $stmt->setFetchMode(PDO::FETCH_ASSOC);
      if ( $stmt->execute($a) ) {
        if ( $row = $stmt->fetch() ) {

          if ( PASSWORD_BCRYPT === true) {
            $status = password_verify($password, $row['password']);
          } else {
            $status = ($password == $row['password']);
          }

          if ( $status ) {
            return true;
          }
        }
      }
    }

    throw new Exception("Invalid login credentials");
  }

  /**
   * This enables full privileges for all users. Simply remove to make use of the groups
   *
   * @see APIUser
   * @param null $requires
   * @throws Exception
   */
  public static function checkPrivilege($requires = null) {
    APIHandler::checkPrivilege(true);
  }
}


API::AddHandler('login', ['MysqlAPIHandler', 'login']);
API::AddHandler('logout', ['MysqlAPIHandler', 'logout']);
API::AddHandler('settings', ['MysqlAPIHandler', 'settings']);
API::SetHandler('MysqlAPIHandler');

?>