using System.Text;
using MessagePack;
using Microsoft.Extensions.Hosting;
using NetMQ;
using NetMQ.Monitoring; // ★ 1. 必须引用 Monitoring 命名空间
using NetMQ.Sockets;
using SHH.CameraSdk;
using SHH.Contracts;

namespace SHH.CameraService;

public class CommandClientWorker : BackgroundService
{
    private readonly ServiceConfig _config;
    private readonly CommandDispatcher _dispatcher;
    private readonly InterceptorPipeline _pipeline;

    // 管理多个 Socket
    private readonly List<DealerSocket> _sockets = new();

    // ★ 2. 新增：保存 Monitor 列表，防止被 GC 回收
    private readonly List<NetMQMonitor> _monitors = new();

    private NetMQPoller? _poller;

    public CommandClientWorker(
        ServiceConfig config,
        CommandDispatcher dispatcher,
        InterceptorPipeline pipeline)
    {
        _config = config;
        _dispatcher = dispatcher;
        _pipeline = pipeline;
    }

    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
    {
        await Task.Yield();

        if (!_config.ShouldConnect || _config.CommandEndpoints.Count == 0) return;

        _poller = new NetMQPoller();

        // -------------------------------------------------------------
        // 核心修改区：建立连接并挂载监控器
        // -------------------------------------------------------------
        foreach (var ep in _config.CommandEndpoints)
        {
            try
            {
                var socket = new DealerSocket();
                socket.Options.Identity = Encoding.UTF8.GetBytes(_config.AppId);

                var monitorUrl = $"inproc://monitor_{Guid.NewGuid():N}";
                var monitor = new NetMQMonitor(socket, monitorUrl, SocketEvents.Connected);

                monitor.Connected += async (s, args) =>
                {
                    Console.WriteLine($"[指令] 网络连接建立: {ep.Uri} -> 正在补发注册包...");
                    await SendRegisterAsync(socket);
                };

                // ★★★ 修正点：使用 AttachToPoller 代替 Add ★★★
                // 错误写法: _poller.Add(monitor); 
                monitor.AttachToPoller(_poller);

                // 依然需要保存引用，防止被 GC 回收
                _monitors.Add(monitor);

                socket.Connect(ep.Uri);
                socket.ReceiveReady += OnSocketReceiveReady;

                _sockets.Add(socket);
                _poller.Add(socket);

                Console.WriteLine($"[指令] 通道初始化完成: {ep.Uri} (带自动重连监控)");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"[指令] 连接初始化异常: {ex.Message}");
            }
        }

        if (_sockets.Count == 0) return;

        // =================================================================
        // 6. 绑定 ACK 逻辑 (保持不变)
        // =================================================================
        _dispatcher.OnResponseReady += async (result) =>
        {
            try
            {
                byte[] resultBytes = MessagePackSerializer.Serialize(result);
                var ctx = await _pipeline.ExecuteSendAsync(ProtocolHeaders.CommandResult, resultBytes);

                if (ctx != null)
                {
                    foreach (var socket in _sockets)
                    {
                        socket.SendMoreFrame(ctx.Protocol).SendFrame(ctx.Data);
                    }
                    Console.WriteLine($"[指令] ACK 已广播 (ID: {result.RequestId})");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"[ACK] 发送失败: {ex.Message}");
            }
        };

        // =================================================================
        // 7. 启动 Poller
        // =================================================================
        // 注意：我们不需要手动发第一次注册包了，
        // 因为 Poller 启动后，底层 TCP 会建立连接，从而触发 monitor.Connected 事件，
        // 事件里会自动发送注册包。这就是“自动档”的好处。
        _poller.RunAsync();

        // 阻塞直到取消
        while (!stoppingToken.IsCancellationRequested)
        {
            await Task.Delay(1000, stoppingToken);
        }

        // 清理
        _poller.Stop();
        _poller.Dispose();
        foreach (var m in _monitors) m.Dispose(); // 释放监控器
        foreach (var s in _sockets) s.Dispose();
    }

    // =================================================================
    // ★ 8. 抽离出的注册包发送逻辑 (供 Monitor 调用)
    // =================================================================
    private async Task SendRegisterAsync(DealerSocket targetSocket)
    {
        try
        {
            var registerPayload = new RegisterPayload
            {
                Protocol = ProtocolHeaders.ServerRegister,
                InstanceId = _config.AppId,
                ProcessId = Environment.ProcessId,
                Version = "1.0.0",
                ServerIp = "127.0.0.1", // 建议优化：获取本机真实IP
                WebApiPort = _config.BasePort,
                StartTime = DateTime.Now
            };

            byte[] regData = MessagePackSerializer.Serialize(registerPayload);

            // 执行拦截器
            var ctx = await _pipeline.ExecuteSendAsync(ProtocolHeaders.ServerRegister, regData);

            if (ctx != null)
            {
                // 直接向触发事件的那个 Socket 发送
                // DealerSocket 允许在连接未完全就绪时 Send，它会缓存直到网络通畅
                targetSocket.SendMoreFrame(ctx.Protocol).SendFrame(ctx.Data);
                // Console.WriteLine($"[指令] 身份注册包已推入队列: {targetSocket.Options.Identity}");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[指令] 注册包发送失败: {ex.Message}");
        }
    }

    private async void OnSocketReceiveReady(object? sender, NetMQSocketEventArgs e)
    {
        NetMQMessage incomingMsg = new NetMQMessage();
        if (e.Socket.TryReceiveMultipartMessage(ref incomingMsg))
        {
            if (incomingMsg.FrameCount >= 2)
            {
                try
                {
                    string rawProtocol = incomingMsg[0].ConvertToString();
                    byte[] rawData = incomingMsg[1].ToByteArray();

                    var ctx = await _pipeline.ExecuteReceiveAsync(rawProtocol, rawData);
                    if (ctx != null)
                    {
                        await _dispatcher.DispatchAsync(ctx.Protocol, ctx.Data);
                    }
                }
                catch (Exception ex)
                {
                    Console.WriteLine($"[指令] 处理异常: {ex.Message}");
                }
            }
        }
    }
}