package udp.server.example;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFactory;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.DefaultEventLoopGroup;
import io.netty.channel.ServerChannel;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.socket.DatagramPacket;
import io.netty.handler.timeout.ReadTimeoutHandler;
import io.netty.util.CharsetUtil;
import udpserversocketchannel.channel.UdpServerChannel;

import java.nio.charset.StandardCharsets;

public class ExampleUdpServer {

    public static void main(String[] args) {
        ServerBootstrap bootstrap = new ServerBootstrap()
                .group(new DefaultEventLoopGroup())
                .childHandler(new ChannelInitializer<Channel>() {
                    @Override
                    protected void initChannel(Channel channel) throws Exception {
                        channel.pipeline()
                                .addLast(new ReadTimeoutHandler(2))
                                .addLast(new Echo());
                    }
                });
        if (args.length > 0) {
            int ioThreads = Integer.parseInt(args[0]);
            bootstrap.channelFactory(new ChannelFactory<ServerChannel>() {
                @Override
                public ServerChannel newChannel() {
                    return new UdpServerChannel(ioThreads);
                }
            });
        } else {
            bootstrap.channel(UdpServerChannel.class);
        }
        bootstrap.bind("0.0.0.0", 1122).syncUninterruptibly();
    }

    public static class Echo extends SimpleChannelInboundHandler<DatagramPacket> {//SimpleChannelInboundHandler<ByteBuf> {
        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable e) {
            ctx.channel().close();
        }
        @Override
        public void channelActive(ChannelHandlerContext ctx) throws Exception {
            super.channelActive(ctx);
            System.err.println("ACTIVE: "+ctx.channel().remoteAddress());
        }
        @Override
        public void channelInactive(ChannelHandlerContext ctx) throws Exception {
            super.channelInactive(ctx);
            System.err.println("INACTIVE: "+ctx.channel().remoteAddress());
        }
//        @Override
//        protected void channelRead0(ChannelHandlerContext ctx, ByteBuf bytebuf) throws Exception {
//            System.err.print("DATA: "+bytebuf.toString(StandardCharsets.UTF_8));
//            ctx.channel().writeAndFlush(Unpooled.copiedBuffer(bytebuf));
//        }
        @Override
        protected void channelRead0(ChannelHandlerContext channelHandlerContext, DatagramPacket datagramPacket) throws Exception {
            System.err.println("Echo: Sender hostname: " + datagramPacket.sender().getHostName());
            ChannelFuture f = channelHandlerContext.channel().writeAndFlush(Unpooled.copiedBuffer("QOTM: ", CharsetUtil.UTF_8));
            f.addListener(ChannelFutureListener.CLOSE);
        }
    }

}