/*
 * Copyright 2012 The Netty Project
 *
 * The Netty Project 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 com.github.nettybook.ch8;

import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

import java.net.InetAddress;
import java.util.Date;

/**
 * Handles a server-side channel.
 */
@Sharable
public class TelnetServerHandler extends SimpleChannelInboundHandler<String> {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        ctx.write(InetAddress.getLocalHost().getHostName() + " 서버에 접속 하셨습니다!\r\n");
        ctx.write("현재 시간은 " + new Date() + " 입니다.\r\n");
        ctx.flush();
    }

    @Override
    public void channelRead0(ChannelHandlerContext ctx, String request) throws Exception {
        // Generate and write a response.
        String response;
        boolean close = false;
        if (request.isEmpty()) {
            response = "명령을 입력해 주세요.\r\n";
        }
        else if ("bye".equals(request.toLowerCase())) {
            response = "안녕히 가세요!\r\n";
            close = true;
        }
        else {
            response = "입력하신 명령은 '" + request + "' 입니다.\r\n";
        }

        // TelnetPipelineFactory에 지정된 StringEncoder클래스가 문자열을 버퍼로 변환해 주므로 
        // ChannelBuffer에 전송할 값을 복사하여 전송하지 않고 직접 문자열을 전송한다.   
        ChannelFuture future = ctx.write(response);

        // 클라이언트로부터 bye 명령을 수신하면 close 플래그가 true값이 되므로 연결을 끊는다.
        if (close) {
            future.addListener(ChannelFutureListener.CLOSE);
        }
    }

    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) {
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        cause.printStackTrace();
        ctx.close();
    }
}