package com.qyft.ms.device.server;

import com.qyft.ms.device.config.TcpConfig;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.json.JsonObjectDecoder;
import io.netty.util.CharsetUtil;
import io.netty.util.concurrent.GlobalEventExecutor;
import jakarta.annotation.PostConstruct;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

@Slf4j
@Component
@RequiredArgsConstructor
public class TcpServer {

    private final TcpConfig tcpConfig;

    private EventLoopGroup bossGroup;
    private EventLoopGroup workerGroup;

    private final ChannelGroup clients = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);

    /**
     * 初始化方法，在Spring容器启动后调用
     */
    @PostConstruct
    public void init() {
        if (tcpConfig.isEnable()) {
            new Thread(this::start).start(); // 在独立线程中启动TCP服务器
        }
    }

    /**
     * 启动TCP服务器的方法
     */
    public void start() {
        bossGroup = new NioEventLoopGroup(1); // 创建Boss线程组
        workerGroup = new NioEventLoopGroup(); // 创建Worker线程组
        try {
            ServerBootstrap bootstrap = new ServerBootstrap();
            bootstrap.group(bossGroup, workerGroup)
                    .channel(NioServerSocketChannel.class)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) {
                            // 添加JSON对象解码器到ChannelPipeline
                            ch.pipeline().addLast(new JsonObjectDecoder());
                            // 添加TCP消息处理器到ChannelPipeline
                            ch.pipeline().addLast(new TcpMessageHandler());
                            // 添加客户端到ChannelGroup
                            ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
                                @Override
                                public void channelActive(ChannelHandlerContext ctx) throws Exception {
                                    clients.add(ctx.channel()); // 将新连接的客户端添加到ChannelGroup
                                    super.channelActive(ctx);
                                }

                                @Override
                                public void channelInactive(ChannelHandlerContext ctx) throws Exception {
                                    clients.remove(ctx.channel()); // 从ChannelGroup中移除断开连接的客户端
                                    super.channelInactive(ctx);
                                }
                            });
                        }
                    })
                    .option(ChannelOption.SO_BACKLOG, 128)
                    .childOption(ChannelOption.SO_KEEPALIVE, true);

            // 绑定并开始接受传入连接
            ChannelFuture future = bootstrap.bind(tcpConfig.getPort()).sync();
            log.info("TCP服务器已启动，监听端口: {}", tcpConfig.getPort());

            // 等待服务器套接字关闭
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            log.error("TCP服务器启动过程中发生中断: {}", e.getMessage(), e);
        } finally {
            // 优雅地关闭EventLoopGroup
            workerGroup.shutdownGracefully();
            bossGroup.shutdownGracefully();
        }
    }

    /**
     * 服务器端推送消息的方法
     * @param message 要推送的消息内容
     */
    public void sendMessage(String message) {
        clients.writeAndFlush(Unpooled.copiedBuffer(message, CharsetUtil.UTF_8)); // 将消息推送给所有客户端
    }

    /**
     * 停止TCP服务器的方法
     */
    public void stop() {
        if (workerGroup != null) {
            workerGroup.shutdownGracefully(); // 优雅地关闭Worker线程组
        }
        if (bossGroup != null) {
            bossGroup.shutdownGracefully(); // 优雅地关闭Boss线程组
        }
    }

    // 内部类，处理TCP消息事件
    private static class TcpMessageHandler extends ChannelInboundHandlerAdapter {

        /**
         * 处理接收到的消息
         * @param ctx 通道处理上下文
         * @param msg 接收到的消息
         */
        @Override
        public void channelRead(ChannelHandlerContext ctx, Object msg) {
            // 记录接收到的消息
            log.info("接收到消息: {}", msg.toString());

            // 将ByteBuf转换为字符串
            String messageStr = ((io.netty.buffer.ByteBuf) msg).toString(CharsetUtil.UTF_8);

            // 解析JSON对象
            cn.hutool.json.JSONObject jsonObject = cn.hutool.json.JSONUtil.parseObj(messageStr);

            // 可以在这里添加消息处理逻辑
            // 例如：处理特定字段
            String someField = jsonObject.getStr("someField");
            log.info("解析后的字段值: {}", someField);

            // 新增：五秒后推送消息
            Runnable task = () -> {
                String responseMessage = "服务器推送消息: " + someField;
                ctx.writeAndFlush(Unpooled.copiedBuffer(responseMessage, CharsetUtil.UTF_8)); // 推送消息给客户端
                log.info("五秒后推送消息: {}", responseMessage);
            };
        }

        /**
         * 处理异常事件
         * @param ctx 通道处理上下文
         * @param cause 异常对象
         */
        @Override
        public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
            // 记录异常日志
            log.error("TCP连接发生异常: {}", cause.getMessage(), cause);
            // 关闭当前channel
            ctx.close();
        }
    }
}