//
//  ========================================================================
//  Copyright (c) 1995-2017 Mort Bay Consulting Pty. Ltd.
//  ------------------------------------------------------------------------
//  All rights reserved. This program and the accompanying materials
//  are made available under the terms of the Eclipse Public License v1.0
//  and Apache License v2.0 which accompanies this distribution.
//
//      The Eclipse Public License is available at
//      http://www.eclipse.org/legal/epl-v10.html
//
//      The Apache License v2.0 is available at
//      http://www.opensource.org/licenses/apache2.0.php
//
//  You may elect to redistribute this code under either of these licenses.
//  ========================================================================
//


package org.eclipse.jetty.plus.security;

import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;

import javax.naming.InitialContext;
import javax.naming.NameNotFoundException;
import javax.naming.NamingException;
import javax.servlet.ServletRequest;
import javax.sql.DataSource;

import org.eclipse.jetty.plus.jndi.NamingEntryUtil;
import org.eclipse.jetty.security.IdentityService;
import org.eclipse.jetty.security.MappedLoginService;
import org.eclipse.jetty.server.Server;
import org.eclipse.jetty.server.UserIdentity;
import org.eclipse.jetty.util.log.Log;
import org.eclipse.jetty.util.log.Logger;
import org.eclipse.jetty.util.security.Credential;


/**
 * DataSourceUserRealm
 * <p>
 * Obtain user/password/role information from a database
 * via jndi DataSource.
 */
public class DataSourceLoginService extends MappedLoginService
{
    private static final Logger LOG = Log.getLogger(DataSourceLoginService.class);

    private String _jndiName = "javax.sql.DataSource/default";
    private DataSource _datasource;
    private Server _server;
    private String _userTableName = "users";
    private String _userTableKey = "id";
    private String _userTableUserField = "username";
    private String _userTablePasswordField = "pwd";
    private String _roleTableName = "roles";
    private String _roleTableKey = "id";
    private String _roleTableRoleField = "role";
    private String _userRoleTableName = "user_roles";
    private String _userRoleTableUserKey = "user_id";
    private String _userRoleTableRoleKey = "role_id";
    private int _cacheMs = 30000;
    private long _lastPurge = 0;
    private String _userSql;
    private String _roleSql;
    private boolean _createTables = false;
    
    
    /**
     * DBUser
     */
    public class DBUser extends KnownUser
    {
        private int _key;
        
        public DBUser(String name, Credential credential, int key)
        {
            super(name, credential);
            _key = key;
        }
        
        public int getKey ()
        {
            return _key;
        }
        
    }

    /* ------------------------------------------------------------ */
    public DataSourceLoginService()
    {
    }

    /* ------------------------------------------------------------ */
    public DataSourceLoginService(String name)
    {
        setName(name);
    }

    /* ------------------------------------------------------------ */
    public DataSourceLoginService(String name, IdentityService identityService)
    {
        setName(name);
        setIdentityService(identityService);
    }

    /* ------------------------------------------------------------ */
    public void setJndiName (String jndi)
    {
        _jndiName = jndi;
    }

    /* ------------------------------------------------------------ */
    public String getJndiName ()
    {
        return _jndiName;
    }

    /* ------------------------------------------------------------ */
    public void setServer (Server server)
    {
        _server=server;
    }

    /* ------------------------------------------------------------ */
    public Server getServer()
    {
        return _server;
    }

    /* ------------------------------------------------------------ */
    public void setCreateTables(boolean createTables)
    {
        _createTables = createTables;
    }

    /* ------------------------------------------------------------ */
    public boolean getCreateTables()
    {
        return _createTables;
    }

    /* ------------------------------------------------------------ */
    public void setUserTableName (String name)
    {
        _userTableName=name;
    }

    /* ------------------------------------------------------------ */
    public String getUserTableName()
    {
        return _userTableName;
    }

    /* ------------------------------------------------------------ */
    public String getUserTableKey()
    {
        return _userTableKey;
    }


    /* ------------------------------------------------------------ */
    public void setUserTableKey(String tableKey)
    {
        _userTableKey = tableKey;
    }


    /* ------------------------------------------------------------ */
    public String getUserTableUserField()
    {
        return _userTableUserField;
    }


    /* ------------------------------------------------------------ */
    public void setUserTableUserField(String tableUserField)
    {
        _userTableUserField = tableUserField;
    }


    /* ------------------------------------------------------------ */
    public String getUserTablePasswordField()
    {
        return _userTablePasswordField;
    }


    /* ------------------------------------------------------------ */
    public void setUserTablePasswordField(String tablePasswordField)
    {
        _userTablePasswordField = tablePasswordField;
    }


    /* ------------------------------------------------------------ */
    public String getRoleTableName()
    {
        return _roleTableName;
    }


    /* ------------------------------------------------------------ */
    public void setRoleTableName(String tableName)
    {
        _roleTableName = tableName;
    }


    /* ------------------------------------------------------------ */
    public String getRoleTableKey()
    {
        return _roleTableKey;
    }


    /* ------------------------------------------------------------ */
    public void setRoleTableKey(String tableKey)
    {
        _roleTableKey = tableKey;
    }


    /* ------------------------------------------------------------ */
    public String getRoleTableRoleField()
    {
        return _roleTableRoleField;
    }


    /* ------------------------------------------------------------ */
    public void setRoleTableRoleField(String tableRoleField)
    {
        _roleTableRoleField = tableRoleField;
    }


    /* ------------------------------------------------------------ */
    public String getUserRoleTableName()
    {
        return _userRoleTableName;
    }


    /* ------------------------------------------------------------ */
    public void setUserRoleTableName(String roleTableName)
    {
        _userRoleTableName = roleTableName;
    }


    /* ------------------------------------------------------------ */
    public String getUserRoleTableUserKey()
    {
        return _userRoleTableUserKey;
    }


    /* ------------------------------------------------------------ */
    public void setUserRoleTableUserKey(String roleTableUserKey)
    {
        _userRoleTableUserKey = roleTableUserKey;
    }


    /* ------------------------------------------------------------ */
    public String getUserRoleTableRoleKey()
    {
        return _userRoleTableRoleKey;
    }


    /* ------------------------------------------------------------ */
    public void setUserRoleTableRoleKey(String roleTableRoleKey)
    {
        _userRoleTableRoleKey = roleTableRoleKey;
    }

    /* ------------------------------------------------------------ */
    public void setCacheMs (int ms)
    {
        _cacheMs=ms;
    }

    /* ------------------------------------------------------------ */
    public int getCacheMs ()
    {
        return _cacheMs;
    }

    /* ------------------------------------------------------------ */
    @Override
    protected void loadUsers()
    {
    }
    
 
    /* ------------------------------------------------------------ */
    /** Load user's info from database.
     *
     * @param userName the user name
     */
    @Deprecated
    protected UserIdentity loadUser (String userName)
    {
        try
        {
            try (Connection connection = getConnection();
                    PreparedStatement statement1 = connection.prepareStatement(_userSql))
            {
                statement1.setObject(1, userName);
                try (ResultSet rs1 = statement1.executeQuery())
                {
                    if (rs1.next())
                    {
                        int key = rs1.getInt(_userTableKey);
                        String credentials = rs1.getString(_userTablePasswordField);
                       
                            List<String> roles = new ArrayList<String>();
                            try (PreparedStatement statement2 = connection.prepareStatement(_roleSql))
                            {
                                statement2.setInt(1, key);
                                try (ResultSet rs2 = statement2.executeQuery())
                                {
                                    while (rs2.next())
                                    {
                                        roles.add(rs2.getString(_roleTableRoleField));
                                    }
                                }
                            }
                            return putUser(userName,  Credential.getCredential(credentials), roles.toArray(new String[roles.size()]));
                    }
                }
            }
        }
        catch (NamingException e)
        {
            LOG.warn("No datasource for "+_jndiName, e);
        }
        catch (SQLException e)
        {
            LOG.warn("Problem loading user info for "+userName, e);
        }
        return null;
    }
    
    
    /** 
     * @see org.eclipse.jetty.security.MappedLoginService#loadUserInfo(java.lang.String)
     */
    public KnownUser loadUserInfo (String username)
    {
        try
        {
            try (Connection connection = getConnection();
                    PreparedStatement statement1 = connection.prepareStatement(_userSql))
            {
                statement1.setObject(1, username);
                try (ResultSet rs1 = statement1.executeQuery())
                {
                    if (rs1.next())
                    {
                        int key = rs1.getInt(_userTableKey);
                        String credentials = rs1.getString(_userTablePasswordField);
                        
                        return new DBUser(username, Credential.getCredential(credentials), key);
                    }
                }
            }
        }
        catch (NamingException e)
        {
            LOG.warn("No datasource for "+_jndiName, e);
        }
        catch (SQLException e)
        {
            LOG.warn("Problem loading user info for "+username, e);
        }
        return null;
    }
    
    /** 
     * @see org.eclipse.jetty.security.MappedLoginService#loadRoleInfo(org.eclipse.jetty.security.MappedLoginService.KnownUser)
     */
    public String[] loadRoleInfo (KnownUser user)
    {
        DBUser dbuser = (DBUser)user;

        try
        {
            try (Connection connection = getConnection();
                    PreparedStatement statement2 = connection.prepareStatement(_roleSql))
            {

                List<String> roles = new ArrayList<String>();

                statement2.setInt(1, dbuser.getKey());
                try (ResultSet rs2 = statement2.executeQuery())
                {
                    while (rs2.next())
                    {
                        roles.add(rs2.getString(_roleTableRoleField));
                    }
                    
                    return roles.toArray(new String[roles.size()]);
                }
            }
        }
        catch (NamingException e)
        {
            LOG.warn("No datasource for "+_jndiName, e);
        }
        catch (SQLException e)
        {
            LOG.warn("Problem loading user info for "+user.getName(), e);
        }
        return null;
    }
    
    /* ------------------------------------------------------------ */
    @Override
    public UserIdentity login(String username, Object credentials, ServletRequest request)
    {
        long now = System.currentTimeMillis();
        if (now - _lastPurge > _cacheMs || _cacheMs == 0)
        {
            _users.clear();
            _lastPurge = now;
        }
 
        return super.login(username,credentials, request);
    }

    /* ------------------------------------------------------------ */
    /**
     * Lookup the datasource for the jndiName and formulate the
     * necessary sql query strings based on the configured table
     * and column names.
     *
     * @throws NamingException if unable to init jndi
     * @throws SQLException if unable to init database
     */
    public void initDb() throws NamingException, SQLException
    {
        if (_datasource != null)
            return;

        @SuppressWarnings("unused")
        InitialContext ic = new InitialContext();
        assert ic!=null;

        // TODO Should we try webapp scope too?

        // try finding the datasource in the Server scope
        if (_server != null)
        {
            try
            {
                _datasource = (DataSource)NamingEntryUtil.lookup(_server, _jndiName);
            }
            catch (NameNotFoundException e)
            {
                //next try the jvm scope
            }
        }


        //try finding the datasource in the jvm scope
        if (_datasource==null)
        {
            _datasource = (DataSource)NamingEntryUtil.lookup(null, _jndiName);
        }

        // set up the select statements based on the table and column names configured
        _userSql = "select " + _userTableKey + "," + _userTablePasswordField
                  + " from " + _userTableName
                  + " where "+ _userTableUserField + " = ?";

        _roleSql = "select r." + _roleTableRoleField
                  + " from " + _roleTableName + " r, " + _userRoleTableName
                  + " u where u."+ _userRoleTableUserKey + " = ?"
                  + " and r." + _roleTableKey + " = u." + _userRoleTableRoleKey;

        prepareTables();
    }

    private void prepareTables()
    throws NamingException, SQLException
    {
        if (_createTables)
        {
            boolean autocommit = true;
            Connection connection = getConnection();
            try (Statement stmt = connection.createStatement())
            {
                autocommit = connection.getAutoCommit();
                connection.setAutoCommit(false);
                DatabaseMetaData metaData = connection.getMetaData();

                //check if tables exist
                String tableName = (metaData.storesLowerCaseIdentifiers()? _userTableName.toLowerCase(Locale.ENGLISH): (metaData.storesUpperCaseIdentifiers()?_userTableName.toUpperCase(Locale.ENGLISH): _userTableName));
                try (ResultSet result = metaData.getTables(null, null, tableName, null))
                {
                    if (!result.next())
                    {
                        //user table default
                        /*
                         * create table _userTableName (_userTableKey integer,
                         * _userTableUserField varchar(100) not null unique,
                         * _userTablePasswordField varchar(20) not null, primary key(_userTableKey));
                         */
                        stmt.executeUpdate("create table "+_userTableName+ "("+_userTableKey+" integer,"+
                                _userTableUserField+" varchar(100) not null unique,"+
                                _userTablePasswordField+" varchar(20) not null, primary key("+_userTableKey+"))");
                        if (LOG.isDebugEnabled()) LOG.debug("Created table "+_userTableName);
                    }
                }

                tableName = (metaData.storesLowerCaseIdentifiers()? _roleTableName.toLowerCase(Locale.ENGLISH): (metaData.storesUpperCaseIdentifiers()?_roleTableName.toUpperCase(Locale.ENGLISH): _roleTableName));
                try (ResultSet result = metaData.getTables(null, null, tableName, null))
                {
                    if (!result.next())
                    {
                        //role table default
                        /*
                         * create table _roleTableName (_roleTableKey integer,
                         * _roleTableRoleField varchar(100) not null unique, primary key(_roleTableKey));
                         */
                        String str = "create table "+_roleTableName+" ("+_roleTableKey+" integer, "+
                        _roleTableRoleField+" varchar(100) not null unique, primary key("+_roleTableKey+"))";
                        stmt.executeUpdate(str);
                        if (LOG.isDebugEnabled()) LOG.debug("Created table "+_roleTableName);
                    }
                }

                tableName = (metaData.storesLowerCaseIdentifiers()? _userRoleTableName.toLowerCase(Locale.ENGLISH): (metaData.storesUpperCaseIdentifiers()?_userRoleTableName.toUpperCase(Locale.ENGLISH): _userRoleTableName));
                try (ResultSet result = metaData.getTables(null, null, tableName, null))
                {
                    if (!result.next())
                    {
                        //user-role table
                        /*
                         * create table _userRoleTableName (_userRoleTableUserKey integer,
                         * _userRoleTableRoleKey integer,
                         * primary key (_userRoleTableUserKey, _userRoleTableRoleKey));
                         *
                         * create index idx_user_role on _userRoleTableName (_userRoleTableUserKey);
                         */
                        stmt.executeUpdate("create table "+_userRoleTableName+" ("+_userRoleTableUserKey+" integer, "+
                                _userRoleTableRoleKey+" integer, "+
                                "primary key ("+_userRoleTableUserKey+", "+_userRoleTableRoleKey+"))");
                        stmt.executeUpdate("create index indx_user_role on "+_userRoleTableName+"("+_userRoleTableUserKey+")");
                        if (LOG.isDebugEnabled()) LOG.debug("Created table "+_userRoleTableName +" and index");
                    }
                }
                connection.commit();
            }
            finally
            {
                try
                {
                    connection.setAutoCommit(autocommit);
                }
                catch (SQLException e)
                {
                    if (LOG.isDebugEnabled()) LOG.debug("Prepare tables", e);
                }
                finally
                {
                    try
                    {
                        connection.close();
                    }
                    catch (SQLException e)
                    {
                        if (LOG.isDebugEnabled()) LOG.debug("Prepare tables", e);
                    }
                }
            }
        }
        else if (LOG.isDebugEnabled())
        {
            LOG.debug("createTables false");
        }
    }

    private Connection getConnection ()
    throws NamingException, SQLException
    {
        initDb();
        return _datasource.getConnection();
    }
}