using MessagePack;
using Microsoft.Extensions.Hosting;
using NetMQ;
using NetMQ.Sockets;
using SHH.CameraSdk;
using SHH.Contracts;
using System.Text;

namespace SHH.CameraService;

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

    // ★ 1. 注入拦截器管道管理器
    private readonly InterceptorPipeline _pipeline;

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

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

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

        using var dealer = new DealerSocket();
        string myIdentity = _config.AppId;
        dealer.Options.Identity = Encoding.UTF8.GetBytes(myIdentity);

        foreach (var ep in _config.CommandEndpoints)
        {
            try { dealer.Connect(ep.Uri); }
            catch (Exception ex) { Console.WriteLine($"[指令] 连接失败 {ep.Uri}: {ex.Message}"); }
        }

        string localIp = "127.0.0.1";
        // ... (获取 IP 代码省略，保持不变) ...

        // =================================================================
        // 构建注册包
        // =================================================================
        var registerPayload = new RegisterPayload
        {
            Protocol = ProtocolHeaders.ServerRegister,
            InstanceId = _config.AppId,
            ProcessId = Environment.ProcessId,
            Version = "1.0.0",
            ServerIp = localIp,
            WebApiPort = _config.BasePort,
            StartTime = DateTime.Now
        };

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

            // =============================================================
            // ★ 2. 拦截点 A: 发送注册包 (Outbound)
            // =============================================================
            var ctx = await _pipeline.ExecuteSendAsync(ProtocolHeaders.ServerRegister, regData);

            if (ctx != null) // 如果未被拦截
            {
                // 注意：这里使用 ctx.Protocol 和 ctx.Data，允许拦截器修改内容
                dealer.SendMoreFrame(ctx.Protocol)
                      .SendFrame(ctx.Data);

                Console.WriteLine($"[指令] 注册包已发送 ({ctx.Data.Length} bytes)");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[致命错误] 注册流程异常: {ex.Message}");
            return;
        }

        // =================================================================
        // 定义 ACK 发送逻辑 (包含拦截器)
        // =================================================================
        // 注意：这里需要 async，因为拦截器是异步的
        Action<CommandResult> sendAckHandler = async (result) =>
        {
            try
            {
                byte[] resultBytes = MessagePackSerializer.Serialize(result);

                // =========================================================
                // ★ 3. 拦截点 B: 发送 ACK 回执 (Outbound)
                // =========================================================
                // 协议头是 COMMAND_RESULT
                var ctx = await _pipeline.ExecuteSendAsync(ProtocolHeaders.CommandResult, resultBytes);

                if (ctx != null)
                {
                    dealer.SendMoreFrame(ctx.Protocol)
                          .SendFrame(ctx.Data);

                    Console.WriteLine($"[指令] 已回复 ACK -> Req: {result.RequestId}");
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine($"[ACK Error] 回执发送失败: {ex.Message}");
            }
        };

        // 订阅事件 (需要适配 async void，注意异常捕获)
        _dispatcher.OnResponseReady += async (res) => await Task.Run(() => sendAckHandler(res));

        // =================================================================
        // 接收循环
        // =================================================================
        try
        {
            while (!stoppingToken.IsCancellationRequested)
            {
                NetMQMessage incomingMsg = new NetMQMessage();
                if (dealer.TryReceiveMultipartMessage(TimeSpan.FromMilliseconds(500), ref incomingMsg))
                {
                    if (incomingMsg.FrameCount >= 2)
                    {
                        string rawProtocol = incomingMsg[0].ConvertToString();
                        byte[] rawData = incomingMsg[1].ToByteArray();

                        // =================================================
                        // ★ 4. 拦截点 C: 接收指令 (Inbound)
                        // =================================================
                        var ctx = await _pipeline.ExecuteReceiveAsync(rawProtocol, rawData);

                        if (ctx != null) // 如果未被拦截
                        {
                            // 将处理后的数据交给 Dispatcher
                            await _dispatcher.DispatchAsync(ctx.Protocol, ctx.Data);
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"[指令] 接收循环异常: {ex.Message}");
        }
    }
}