/*
 * 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 io.netty.example.socksproxy;

import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.util.ReferenceCountUtil;

public final class RelayHandler extends ChannelInboundHandlerAdapter {

    private final Channel relayChannel;

    public RelayHandler(Channel relayChannel) {
        this.relayChannel = relayChannel;
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) {
        ctx.writeAndFlush(Unpooled.EMPTY_BUFFER);
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) {
        if (relayChannel.isActive()) {
            relayChannel.writeAndFlush(msg);
        } else {
            ReferenceCountUtil.release(msg);
        }
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) {
        if (relayChannel.isActive()) {
            SocksServerUtils.closeOnFlush(relayChannel);
        }
    }

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