/*
 Nutzerverwaltung - A Generic User Manager
 Copyright (c) 2016  Ulrich Hilger

 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/>.
 */
package de.uhilger.um.api;

import de.uhilger.baselink.GenericRecord;
import de.uhilger.baselink.PersistenceManager;
import de.uhilger.baselink.Record;
import de.uhilger.um.App;
import de.uhilger.um.Digester;
import de.uhilger.um.daten.User;
import de.uhilger.um.daten.UserRole;
import java.sql.Connection;
import java.util.List;

/**
 * Klasse zur Verwaltung von Benutzern und Rollen 
 * in einer Datenbank. Die Datenbankverbindung wird 
 * vom zentralen Anwendungsobjekt bereitgestellt. 
 * 
 * Die SQL-Befehle finden sich in WEB-INF/sql.properties
 * 
 * @author Copyright (c) Ulrich Hilger, http://uhilger.de
 * @author Published under the terms and conditions of the
 * <a href="http://www.gnu.org/licenses/agpl-3.0" target="_blank">GNU Affero
 * General Public License</a>
 *
 * @version 2, December 27, 2016
 */
public class UserMgr {
  
  private static final Record UserMapper = new GenericRecord(User.class);
  private static final Record UserRoleMapper = new GenericRecord(UserRole.class);
  
  public static final String SQL_GET_USER_LIST = "getUserList";
  public static final String SQL_GET_USER_NAME_LIST = "getUserNameList";
  public static final String SQL_GET_ROLE_LIST = "getRoleList";
  public static final String SQL_GET_USER_ROLES = "getUserRoles";
  public static final String SQL_DELETE_USER = "deleteUser";
  public static final String SQL_DELETE_USER_ROLES = "deleteUserRoles";
  
  /* ----------- Benutzer -------------- */
  
  public User createUser(User user) {
    String kw = user.getPw();
    String digestedPw = App.getDigester().digest(kw, Digester.MD5, null);
    user.setPw(digestedPw);
    App.getDatabase().insert(user, UserMapper);
    return user;
  }
  
  public List getUserNameList() {
    String sql = App.getSqlStatement(SQL_GET_USER_NAME_LIST);
    List userNames = App.getDatabase().select(sql, App.WITHOUT_BLOBS);
    return userNames;
  }
  
  public User deleteUser(User user) {
    PersistenceManager pm = App.getDatabase();
    Connection c = pm.getConnection();
    pm.startTransaction(c);
    String sql = App.getSqlStatement(SQL_DELETE_USER_ROLES);
    pm.execute(c, sql, user.getId());
    User deletedUser = (User) pm.delete(c, user, UserMapper);
    pm.commit(c);
    return deletedUser;
  }
    
  /* ------------ Rollen ------------------ */
  
  public UserRole grantRole(String userId, String roleName) {
    UserRole ur = new UserRole();
    ur.setRole(roleName);
    ur.setUser(userId);
    App.getDatabase().insert(ur, UserRoleMapper);
    return ur;
  }
  
  public UserRole revokeRole(String userId, String roleName) {
    UserRole ur = new UserRole();
    ur.setRole(roleName);
    ur.setUser(userId);
    App.getDatabase().delete(ur, UserRoleMapper);
    return ur;
  }
  
  public List getRoleNamesGranted() {
    String sql = App.getSqlStatement(SQL_GET_ROLE_LIST);
    List roleNames = App.getDatabase().select(sql, App.WITHOUT_BLOBS);
    return roleNames;
  }
  
  public List getUserRoleNames(String userId) {
    String sql = App.getSqlStatement(SQL_GET_USER_ROLES);
    List roleNames = App.getDatabase().select(sql, App.WITHOUT_BLOBS, userId);
    return roleNames;
  }
  
}