using System;
using System.Windows.Threading;

namespace ERVSimulator.Model
{
    // 펌웨어 [MyMotor.c] Damper_Mode() + Diffuser_Damper_process() 시퀀스를 흉내
    // - Cmd 변경 시 18초 시퀀스 트리거 (slot 180 / 120 / 60, 100ms tick)
    // - 본체 댐퍼 6개: Run_Mode 에 따라 즉시 목표각 세팅
    // - 디퓨저 댐퍼: Memory → Current 슬롯별 복사
    // - 팬 PWM: 매 tick ±1 ramp
    public class DamperSequencer
    {
        public ErvState State { get; }
        private readonly DispatcherTimer _timer;
        private int _diffuserSlot;       // 180..0 카운트다운
        private int _seqType;            // 1=on, 2=off, 3=decrease, 4=increase
        private int _prevAirVolume;
        private bool _pendingSequence;

        public DamperSequencer(ErvState state)
        {
            State = state;
            _timer = new DispatcherTimer(DispatcherPriority.Normal)
            {
                Interval = TimeSpan.FromMilliseconds(100)
            };
            _timer.Tick += OnTick;
            _timer.Start();
        }

        // RoomCon/HomeNet 핸들러가 Run_Mode/Fan_Mode 갱신 후 호출
        public void NotifyCommandChanged()
        {
            _pendingSequence = true;
        }

        void OnTick(object? sender, EventArgs e)
        {
            // ---- Fan_Speed_process() 시작부: VENT && Fan=0 → 정지 진입 ----
            int newAirVolume = (State.RunMode != RunMode.Off && State.FanMode != 0) ? State.FanMode : 0;

            if (_pendingSequence)
            {
                _pendingSequence = false;
                _diffuserSlot = 180;
                _seqType = DetermineSeqType(_prevAirVolume, newAirVolume);
                _prevAirVolume = newAirVolume;
            }

            // ---- Damper_Mode(Run_Mode) — 본체 댐퍼 즉시 목표각 ----
            ApplyBodyDamperMode(EffectiveBodyMode());

            // ---- Diffuser_Damper_process() — 슬롯 기반 적용 ----
            if (_diffuserSlot == 180)
            {
                if (_seqType == 1 || _seqType == 4)
                    CopyMemoryToCurrent(1, 2);
                else if (_seqType == 2 || _seqType == 3)
                    SetFanTargets(); // 즉시 ramp 시작
            }
            else if (_diffuserSlot == 120)
            {
                if (_seqType == 1 || _seqType == 4 || _seqType == 2 || _seqType == 3)
                    CopyMemoryToCurrent(3, 4);
            }
            else if (_diffuserSlot == 60)
            {
                if (_seqType == 1 || _seqType == 4)
                    SetFanTargets();
                else if (_seqType == 2 || _seqType == 3)
                    CopyMemoryToCurrent(1, 2);
            }

            if (_diffuserSlot > 0) _diffuserSlot--;

            // ---- 팬 ramp ±1 (펌웨어와 동일) ----
            if (State.Fan1Current < State.Fan1Target) State.Fan1Current++;
            else if (State.Fan1Current > State.Fan1Target) State.Fan1Current--;
            if (State.Fan2Current < State.Fan2Target) State.Fan2Current++;
            else if (State.Fan2Current > State.Fan2Target) State.Fan2Current--;
        }

        int DetermineSeqType(int prev, int now)
        {
            if (prev == 0 && now != 0) return 4; // increase (power on)
            if (prev != 0 && now == 0) return 3; // decrease (power off)
            if (prev > now) return 3;
            return 4;
        }

        RunMode EffectiveBodyMode()
        {
            // VENT && Fan=0 → 본체 댐퍼는 MODE_OFF 로 진입 (펌웨어 Fan_Speed_process 분기)
            if (State.RunMode == RunMode.Off) return RunMode.Off;
            if (State.RunMode == RunMode.Ventilation && State.FanMode == 0 &&
                State.Fan1Current == 0 && State.Fan2Current == 0)
                return RunMode.Off;
            return State.RunMode;
        }

        // 펌웨어 Damper_Mode() — MyMotor.c:472
        void ApplyBodyDamperMode(RunMode mode)
        {
            switch (mode)
            {
                case RunMode.Ventilation:
                    SetBody(DamperId.OA, 0); SetBody(DamperId.EA, 0); SetBody(DamperId.BYPASS, 100);
                    SetBody(DamperId.SA, 0); SetBody(DamperId.RA, 70); SetBody(DamperId.AIR, 105);
                    break;
                case RunMode.AirClean:
                    SetBody(DamperId.OA, 100); SetBody(DamperId.EA, 100); SetBody(DamperId.BYPASS, 100);
                    SetBody(DamperId.SA, 0); SetBody(DamperId.RA, 140); SetBody(DamperId.AIR, 0);
                    break;
                case RunMode.Bypass:
                    SetBody(DamperId.OA, 0); SetBody(DamperId.EA, 0); SetBody(DamperId.BYPASS, 0);
                    SetBody(DamperId.SA, 0); SetBody(DamperId.RA, 140); SetBody(DamperId.AIR, 105);
                    break;
                case RunMode.Auto:
                    // 펌웨어는 자동 시 공기질에 따라 VENT/AIR 선택. 단순화: VENT 와 동일.
                    SetBody(DamperId.OA, 0); SetBody(DamperId.EA, 0); SetBody(DamperId.BYPASS, 100);
                    SetBody(DamperId.SA, 0); SetBody(DamperId.RA, 70); SetBody(DamperId.AIR, 105);
                    break;
                case RunMode.Off:
                default:
                    SetBody(DamperId.OA, 100); SetBody(DamperId.EA, 100); SetBody(DamperId.BYPASS, 100);
                    SetBody(DamperId.SA, 100); SetBody(DamperId.RA, 0); SetBody(DamperId.AIR, 105);
                    break;
            }
        }

        void SetBody(DamperId id, int angle) => State.GetDamper(id).TargetAngle = angle;

        void CopyMemoryToCurrent(int fromRoom, int toRoom)
        {
            for (int r = fromRoom; r <= toRoom; r++)
            {
                var room = State.GetRoom(r);
                room.CurrentSA = room.MemorySA;
                room.CurrentRA = room.MemoryRA;
            }
        }

        // 펌웨어 Fan_Speed_Setting(Run_Mode, Fan_Mode) — MyMotor.c:1233
        void SetFanTargets()
        {
            int idx = System.Math.Clamp(State.FanMode, (byte)0, (byte)4);
            switch (State.RunMode)
            {
                case RunMode.Ventilation:
                case RunMode.Auto:
                    State.Fan1Target = State.FanSAPreset_Vent[idx];
                    State.Fan2Target = State.FanEAPreset_Vent[idx];
                    break;
                case RunMode.Bypass:
                    State.Fan1Target = State.FanSAPreset_Bypass[idx];
                    State.Fan2Target = State.FanEAPreset_Bypass[idx];
                    break;
                case RunMode.AirClean:
                    State.Fan1Target = State.FanSAPreset_Air[idx];
                    State.Fan2Target = State.FanEAPreset_Air[idx];
                    break;
                default:
                    State.Fan1Target = 0;
                    State.Fan2Target = 0;
                    break;
            }
        }
    }
}