/*

  * Copyright 2008 the original author or authors.

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *      http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.mockftpserver.fake.command;

 import org.mockftpserver.core.command.Command;

 import org.mockftpserver.core.command.ReplyCodes;

 import org.mockftpserver.core.session.Session;

 import org.mockftpserver.core.util.StringUtil;

 import java.util.List;

 /**

  * CommandHandler for the NLST command. Handler logic:

  * <ol>

  * <li>If the user has not logged in, then reply with 530 and terminate</li>

  * <li>Send an initial reply of 150</li>

  * <li>If the current user does not have read access to the file or directory to be listed, then reply with 550 and terminate</li>

  * <li>If an error occurs during processing, then send a reply of 451 and terminate</li>

  * <li>If the optional pathname parameter is missing, then send a directory listing for

  * the current directory across the data connection</li>

  * <li>Otherwise, if the optional pathname parameter specifies a directory or group of files,

  * then send a directory listing for the specified directory across the data connection</li>

  * <li>Otherwise, if the pathname parameter does not specify an existing directory or group of files,

  * then send an empty response across the data connection</li>

  * <li>Send a final reply with 226</li>

  * </ol>

  * The directory listing sent includes filenames only, separated by end-of-line characters.

  *

  * @author Chris Mair

  * @version $Revision: 220 $ - $Date: 2009-02-07 23:05:06 -0500 (Sat, 07 Feb 2009) $

  */

 public class NlstCommandHandler extends AbstractFakeCommandHandler {

     protected void handle(Command command, Session session) {

         verifyLoggedIn(session);

         sendReply(session, ReplyCodes.TRANSFER_DATA_INITIAL_OK);

         String path = getRealPath(session, command.getParameter(0));

         // User must have read permission to the path

         if (getFileSystem().exists(path)) {

             this.replyCodeForFileSystemException = ReplyCodes.READ_FILE_ERROR;

             verifyReadPermission(session, path);

         }

         this.replyCodeForFileSystemException = ReplyCodes.SYSTEM_ERROR;

         List names = getFileSystem().listNames(path);

         String directoryListing = StringUtil.join(names, endOfLine());

         directoryListing += directoryListing.length() > 0 ? endOfLine() : "";

         session.openDataConnection();

         session.sendData(directoryListing.getBytes(), directoryListing.length());

         session.closeDataConnection();

         sendReply(session, ReplyCodes.TRANSFER_DATA_FINAL_OK);

     }

 }