package com.eactive.httpmockserver.socket;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.annotation.PreDestroy;
import javax.persistence.NoResultException;

@Component
public class EchoSocketServer {
	private final Logger logger = LoggerFactory.getLogger(this.getClass());

	private BytesMessageSpec spec;

	EventLoopGroup bossGroup;
	EventLoopGroup workerGroup;
	ChannelFuture channelFuture;

	public EchoSocketServer() {
	}

	public EchoSocketServer(BytesMessageSpec spec) {
		this.spec = spec;
	}

	public void start() throws Exception {
		if (spec == null) {
			throw new NoResultException();
		}

		int port = (spec.getPort() == null ? 38181 : spec.getPort().intValue());
		bossGroup = new NioEventLoopGroup();
		workerGroup = new NioEventLoopGroup();
		try {
			ServerBootstrap server = new ServerBootstrap();
			// @formatter:off
			server.group(bossGroup, workerGroup)
					.channel(NioServerSocketChannel.class)
					.childHandler(new ChannelInitializer<SocketChannel>() {
						@Override
						protected void initChannel(SocketChannel ch) throws Exception {
							ChannelPipeline pipeline = ch.pipeline();
							pipeline.addLast(new LengthHeaderFrameDecoder(spec));
							pipeline.addLast(new EchoSocketServerHandler(spec));
						}
					})
					.option(ChannelOption.SO_BACKLOG, 128)
					.childOption(ChannelOption.SO_KEEPALIVE, false);
			// @formatter:on

			channelFuture = server.bind(port).sync();
			channelFuture.channel().closeFuture().sync().channel();
			logger.info(port + " port bounded");
		} catch (Exception e) {
			logger.error(e.getMessage());
			throw e;
		} finally {
			bossGroup.shutdownGracefully();
			workerGroup.shutdownGracefully();
		}
	}

	@PreDestroy
	public void stop() {
		try {
			bossGroup.shutdownGracefully().sync();
			workerGroup.shutdownGracefully().sync();
			channelFuture.channel().closeFuture().sync();
		} catch (InterruptedException e) {
			logger.error(e.getMessage());
		}
	}
}