/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.ftpserver.command.impl;

import java.io.IOException;
import java.util.HashMap;

import org.apache.ftpserver.command.AbstractCommand;
import org.apache.ftpserver.command.Command;
import org.apache.ftpserver.ftplet.FtpException;
import org.apache.ftpserver.ftplet.FtpReply;
import org.apache.ftpserver.ftplet.FtpRequest;
import org.apache.ftpserver.impl.FtpIoSession;
import org.apache.ftpserver.impl.FtpServerContext;
import org.apache.ftpserver.impl.LocalizedFtpReply;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * <strong>Internal class, do not use directly.</strong>
 * 
 * <code>OPTS&lt;SP&gt; <command> &lt;SP&gt; <option> &lt;CRLF&gt;</code><br>
 * 
 * This command shall cause the server use optional features for the command
 * specified.
 *
 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
 */
public class OPTS extends AbstractCommand {

    private final Logger LOG = LoggerFactory.getLogger(OPTS.class);

    private static final HashMap<String, Command> COMMAND_MAP = new HashMap<>(
            16);

    /**
     * Execute command.
     */
    public void execute(final FtpIoSession session,
            final FtpServerContext context, final FtpRequest request)
            throws IOException, FtpException {

        // reset state
        session.resetState();

        // no params
        String argument = request.getArgument();
        if (argument == null) {
            session.write(LocalizedFtpReply.translate(session, request, context,
                    FtpReply.REPLY_501_SYNTAX_ERROR_IN_PARAMETERS_OR_ARGUMENTS,
                    "OPTS", null));
            return;
        }

        // get request name
        int spaceIndex = argument.indexOf(' ');
        if (spaceIndex != -1) {
            argument = argument.substring(0, spaceIndex);
        }
        argument = argument.toUpperCase();

        // call appropriate command method
        String optsRequest = "OPTS_" + argument;
        Command command = COMMAND_MAP.get(optsRequest);
        try {
            if (command != null) {
                command.execute(session, context, request);
            } else {
                session.resetState();
                session.write(LocalizedFtpReply.translate(session, request, context,
                        FtpReply.REPLY_502_COMMAND_NOT_IMPLEMENTED,
                        "OPTS.not.implemented", argument));
            }
        } catch (Exception ex) {
            LOG.warn("OPTS.execute()", ex);
            session.resetState();
            session.write(LocalizedFtpReply.translate(session, request, context,
                    FtpReply.REPLY_500_SYNTAX_ERROR_COMMAND_UNRECOGNIZED,
                    "OPTS", null));
        }
    }

    // initialize all the OPTS command handlers
    static {
        COMMAND_MAP.put("OPTS_MLST",
                new org.apache.ftpserver.command.impl.OPTS_MLST());
        COMMAND_MAP.put("OPTS_UTF8",
                new org.apache.ftpserver.command.impl.OPTS_UTF8());
    }
}