using ErvDashboard.Protocol;   // SerialChannel, HexFormat
using ErvProtocol;

namespace ErvDashboard.Api
{
    // IErvApi 의 RS485(시리얼) 구현. 시리얼 채널 + 공용 프레임 파서/빌더(CtrlFrame, StatusDecoder)를 내장한다.
    // UI 비종속 : STATUS 는 StatusRecord 이벤트로만 알리고, DashboardState 매핑은 호출부(MainWindow)가 담당.
    public sealed class SerialErvApi : IErvApi
    {
        readonly SerialChannel _ch = new();
        readonly FrameParser _parser = new();

        DateTime _lastByte = DateTime.MinValue;
        static readonly TimeSpan FrameGap = TimeSpan.FromMilliseconds(60);

        StatusRecord? _lastStatus;   // 최근 수신 STATUS (GetRoomStatus 조회용)

        public event Action<bool>? ConnectionChanged;
        public event Action<StatusRecord>? StatusReceived;
        public event Action<string>? Log;

        public bool IsConnected => _ch.IsConnected;

        public static string[] GetAvailablePorts() => SerialChannel.GetAvailablePorts();

        public SerialErvApi()
        {
            _ch.ByteReceived += OnByte;
            _ch.Log += s => Log?.Invoke(s);
            _ch.ConnectionChanged += b => ConnectionChanged?.Invoke(b);
            _parser.OnFrame += HandleFrame;
            _parser.OnError += m => Log?.Invoke("RX " + m);
        }

        public bool Connect(string port, int baud) => _ch.Connect(port, baud);
        public void Disconnect() => _ch.Disconnect();

        // 최근 STATUS 기준 각실(room 1~4) 상태 조회
        public bool GetRoomStatus(int room, out bool damperSa, out bool damperEa, out AirQuality airQuality, out int led)
        {
            damperSa = false; damperEa = false; airQuality = AirQuality.Normal; led = 0;
            var s = _lastStatus;
            if (s == null || room < 1 || room > 4) return false;
            var r = s.Rooms[room - 1];
            damperSa = r.DamperSa;
            damperEa = r.DamperEa;
            airQuality = (AirQuality)r.AirQuality;
            led = r.LedDim;
            return true;
        }

        // 시리얼 바이트 → 공용 파서 (프레임 갭 시 동기 리셋)
        void OnByte(byte b)
        {
            var now = DateTime.UtcNow;
            if (now - _lastByte > FrameGap) _parser.Reset();
            _lastByte = now;
            _parser.FeedByte(b);
        }

        void HandleFrame(byte cmd, byte[] p)
        {
            switch (cmd)
            {
                case StatusDecoder.STATUS:
                    Log?.Invoke($"RX STATUS ({p.Length}B)");
                    var rec = StatusDecoder.Decode(p);
                    if (rec != null) { _lastStatus = rec; StatusReceived?.Invoke(rec); }
                    else Log?.Invoke($"  STATUS too short ({p.Length}<{StatusDecoder.STATUS_LEN})");
                    break;
                case StatusDecoder.ACK:
                    if (p.Length >= 2)
                        Log?.Invoke($"RX ACK echo=0x{p[0]:X2} result={(p[1] == 0 ? "OK" : "ERR")}");
                    break;
                default:
                    Log?.Invoke($"RX unknown cmd=0x{cmd:X2}");
                    break;
            }
        }

        // ================= 송신 (공용 CtrlFrame) =================
        void SendFrame(byte[] f)
        {
            if (_ch.Send(f, f.Length))
                Log?.Invoke($"TX {HexFormat.Bytes(f, f.Length)}");
        }

        public void RequestStatus()                    => SendFrame(CtrlFrame.RequestStatus());
        public void SetPower(bool on)                  => SendFrame(CtrlFrame.Power(on ? 1 : 0));
        public void SetRunMode(RunMode mode)           => SendFrame(CtrlFrame.RunModeCmd((int)mode));
        public void SetFan(int speed)                  => SendFrame(CtrlFrame.Fan(speed));
        public void SetSubMode(SubModeType type, bool on) => SendFrame(CtrlFrame.SubMode((int)type, on ? 1 : 0));
        public void SetHood(bool on)                   => SendFrame(CtrlFrame.Hood(on ? 1 : 0));
        public void SetReserve(int hours)              => SendFrame(CtrlFrame.Reserve(hours));
        public void SetReset(bool on)                  => SendFrame(CtrlFrame.Reset(on ? 1 : 0));
        public void SetDiffuserDamper(int room, int type, bool open) => SendFrame(CtrlFrame.Damper(room, type, open ? 1 : 0));
        public void SetDiffuserLed(int room, int dim)      => SendFrame(CtrlFrame.Led(room, dim));
        public void SetVsp(int group, int index, int sa, int ea) => SendFrame(CtrlFrame.Vsp(group, index, sa, ea));
        public void SetHystPreset(HystPreset preset)   => SendFrame(CtrlFrame.Preset((int)preset));
        public void SetHystDeadband(int preset, int pm25, int pm10, int voc, int co2) => SendFrame(CtrlFrame.HystValue(preset, pm25, pm10, voc, co2));
        public void SetHystThreshold(int preset, int pollutant, int l1, int l2, int l3, int l4) => SendFrame(CtrlFrame.HystThr(preset, pollutant, l1, l2, l3, l4));

        public void Dispose() => _ch.Dispose();
    }
}