namespace Sand.ChunkPrototype;

internal sealed class ChunkCellPage
{
    private readonly PrototypeParticle[] _particles;
    private readonly int[] _processedStep;
    private readonly int[] _occupiedRowCounts;
    private readonly int[] _gasRowCounts;
    private readonly int[] _rowRevision;
    private readonly int[] _blockedSolidSignature;
    private readonly int[] _blockedGasRiseSignature;
    private readonly int[] _gasRetrySignature;
    private readonly int[] _gasRetryUntilStep;
    private readonly int[] _gasRowCooldownSignature;
    private readonly int[] _gasRowCooldownUntilStep;
    private readonly sbyte[] _driftState;
    private readonly float[] _pressureDuration;
    private readonly float[] _temperature;
    private readonly float[] _burnTime;
    private readonly byte[] _burning;
    private readonly short[] _sparkTime;
    private readonly float[] _lifetime;
    private readonly float[] _cellAge;
    private readonly float[] _integrity;

    public ChunkCellPage(int width, int height)
    {
        Width = width;
        Height = height;
        _particles = new PrototypeParticle[width * height];
        _processedStep = new int[width * height];
        _occupiedRowCounts = new int[height];
        _gasRowCounts = new int[height];
        _rowRevision = new int[height];
        _blockedSolidSignature = new int[width * height];
        _blockedGasRiseSignature = new int[width * height];
        _gasRetrySignature = new int[width * height];
        _gasRetryUntilStep = new int[width * height];
        _gasRowCooldownSignature = new int[height];
        _gasRowCooldownUntilStep = new int[height];
        _driftState = new sbyte[width * height];
        _pressureDuration = new float[width * height];
        _temperature = new float[width * height];
        _burnTime = new float[width * height];
        _burning = new byte[width * height];
        _sparkTime = new short[width * height];
        _lifetime = new float[width * height];
        _cellAge = new float[width * height];
        _integrity = new float[width * height];
        ClearDirtyBands();
        ClearVisualDirty();
    }

    public int Width { get; }
    public int Height { get; }
    public int OccupancyCount { get; private set; }
    public int GasCellCount { get; private set; }
    public int DynamicCellCount { get; private set; }
    public int RuntimeCellCount { get; private set; }
    public int PendingActiveSteps { get; private set; }
    public bool IsActive { get; set; } = true;
    public bool HasFieldActivity { get; set; }
    public int LastTouchedFrame { get; set; }
    public int DirtyMinRow { get; private set; }
    public int DirtyMaxRow { get; private set; }
    public int DirtyMinCol { get; private set; }
    public int DirtyMaxCol { get; private set; }
    public bool HasDirtyBands { get; private set; }
    public int VisualDirtyMinRow { get; private set; }
    public int VisualDirtyMaxRow { get; private set; }
    public int VisualDirtyMinCol { get; private set; }
    public int VisualDirtyMaxCol { get; private set; }
    public bool HasVisualDirty { get; private set; }

    public PrototypeParticle this[int localX, int localY]
    {
        get => _particles[GetIndex(localX, localY)];
        set => _particles[GetIndex(localX, localY)] = value;
    }

    public bool IsProcessed(int localX, int localY, int stepToken) => _processedStep[GetIndex(localX, localY)] == stepToken;

    public void MarkProcessed(int localX, int localY, int stepToken) => _processedStep[GetIndex(localX, localY)] = stepToken;

    public bool IsOccupied(int localX, int localY) => _particles[GetIndex(localX, localY)].TypeId != 0;

    public int GetOccupiedRowCount(int localY) => _occupiedRowCounts[localY];

    public int GetGasRowCount(int localY) => _gasRowCounts[localY];

    public int GetRowRevision(int localY) => _rowRevision[localY];

    public int GetBlockedSolidSignature(int localX, int localY) => _blockedSolidSignature[GetIndex(localX, localY)];

    public void SetBlockedSolidSignature(int localX, int localY, int signature) => _blockedSolidSignature[GetIndex(localX, localY)] = signature;

    public int GetBlockedGasRiseSignature(int localX, int localY) => _blockedGasRiseSignature[GetIndex(localX, localY)];

    public void SetBlockedGasRiseSignature(int localX, int localY, int signature) => _blockedGasRiseSignature[GetIndex(localX, localY)] = signature;

    public int GetGasRetrySignature(int localX, int localY) => _gasRetrySignature[GetIndex(localX, localY)];

    public int GetGasRetryUntilStep(int localX, int localY) => _gasRetryUntilStep[GetIndex(localX, localY)];

    public void SetGasRetryState(int localX, int localY, int signature, int untilStep)
    {
        var index = GetIndex(localX, localY);
        _gasRetrySignature[index] = signature;
        _gasRetryUntilStep[index] = untilStep;
    }

    public void ClearGasRetryState(int localX, int localY)
    {
        var index = GetIndex(localX, localY);
        _gasRetrySignature[index] = 0;
        _gasRetryUntilStep[index] = 0;
    }

    public int GetGasRowCooldownSignature(int localY) => _gasRowCooldownSignature[localY];

    public int GetGasRowCooldownUntilStep(int localY) => _gasRowCooldownUntilStep[localY];

    public void SetGasRowCooldown(int localY, int signature, int untilStep)
    {
        _gasRowCooldownSignature[localY] = signature;
        _gasRowCooldownUntilStep[localY] = untilStep;
    }

    public void ClearGasRowCooldown(int localY)
    {
        _gasRowCooldownSignature[localY] = 0;
        _gasRowCooldownUntilStep[localY] = 0;
    }

    public sbyte GetDriftState(int localX, int localY) => _driftState[GetIndex(localX, localY)];

    public void SetDriftState(int localX, int localY, sbyte driftState) => _driftState[GetIndex(localX, localY)] = driftState;

    public float GetPressureDuration(int localX, int localY) => _pressureDuration[GetIndex(localX, localY)];

    public void SetPressureDuration(int localX, int localY, float value) => _pressureDuration[GetIndex(localX, localY)] = value;

    public float GetTemperature(int localX, int localY) => _temperature[GetIndex(localX, localY)];

    public void SetTemperature(int localX, int localY, float value) => _temperature[GetIndex(localX, localY)] = value;

    public float GetBurnTime(int localX, int localY) => _burnTime[GetIndex(localX, localY)];

    public void SetBurnTime(int localX, int localY, float value) => _burnTime[GetIndex(localX, localY)] = value;

    public byte GetBurning(int localX, int localY) => _burning[GetIndex(localX, localY)];

    public void SetBurning(int localX, int localY, byte value) => _burning[GetIndex(localX, localY)] = value;

    public short GetSparkTime(int localX, int localY) => _sparkTime[GetIndex(localX, localY)];

    public void SetSparkTime(int localX, int localY, short value) => _sparkTime[GetIndex(localX, localY)] = value;

    public float GetLifetime(int localX, int localY) => _lifetime[GetIndex(localX, localY)];

    public void SetLifetime(int localX, int localY, float value) => _lifetime[GetIndex(localX, localY)] = value;

    public float GetCellAge(int localX, int localY) => _cellAge[GetIndex(localX, localY)];

    public void SetCellAge(int localX, int localY, float value) => _cellAge[GetIndex(localX, localY)] = value;

    public float GetIntegrity(int localX, int localY) => _integrity[GetIndex(localX, localY)];

    public void SetIntegrity(int localX, int localY, float value) => _integrity[GetIndex(localX, localY)] = value;

    public void SetCell(int localX, int localY, PrototypeParticle particle)
    {
        var index = GetIndex(localX, localY);
        var previous = _particles[index];
        if (previous.TypeId == 0 && particle.TypeId != 0)
        {
            OccupancyCount++;
            _occupiedRowCounts[localY]++;
            _rowRevision[localY]++;
        }
        else if (previous.TypeId != 0 && particle.TypeId == 0)
        {
            OccupancyCount--;
            _occupiedRowCounts[localY]--;
            _rowRevision[localY]++;
        }
        else if (previous.TypeId != particle.TypeId)
        {
            _rowRevision[localY]++;
        }

        if (previous.MotionType == PrototypeParticleType.Steam)
        {
            GasCellCount--;
            _gasRowCounts[localY]--;
        }

        if (previous.TypeId != 0 && !previous.IsStatic)
        {
            DynamicCellCount--;
        }

        if (previous.TypeId != 0 && previous.RequiresFullRuntimeStep)
        {
            RuntimeCellCount--;
        }

        _particles[index] = particle;
        if (particle.MotionType == PrototypeParticleType.Steam)
        {
            GasCellCount++;
            _gasRowCounts[localY]++;
        }

        if (particle.TypeId != 0 && !particle.IsStatic)
        {
            DynamicCellCount++;
        }

        if (particle.TypeId != 0 && particle.RequiresFullRuntimeStep)
        {
            RuntimeCellCount++;
        }

        if (particle.TypeId == 0)
        {
            _driftState[index] = 0;
            _pressureDuration[index] = 0f;
            _temperature[index] = 0f;
            _burnTime[index] = 0f;
            _burning[index] = 0;
            _sparkTime[index] = 0;
            _lifetime[index] = 0f;
            _cellAge[index] = 0f;
            _integrity[index] = 0f;
        }

        _blockedSolidSignature[index] = 0;
        _blockedGasRiseSignature[index] = 0;
        _gasRetrySignature[index] = 0;
        _gasRetryUntilStep[index] = 0;
        _gasRowCooldownSignature[localY] = 0;
        _gasRowCooldownUntilStep[localY] = 0;
        MarkTouched(localX, localY);
    }

    public void MarkTouched(int localX, int localY)
    {
        MarkDirtyBand(localX, localY);
        MarkVisualDirty(localX, localY);
        IsActive = true;
        PendingActiveSteps = Math.Max(PendingActiveSteps, 1);
    }

    public void RequestFutureSteps(int steps)
    {
        if (steps > PendingActiveSteps)
        {
            PendingActiveSteps = steps;
        }
    }

    public void DecayPendingSteps()
    {
        if (PendingActiveSteps > 0)
        {
            PendingActiveSteps--;
        }
    }

    public void MarkDirtyBand(int localX, int localY)
    {
        if (!HasDirtyBands)
        {
            DirtyMinRow = DirtyMaxRow = localY;
            DirtyMinCol = DirtyMaxCol = localX;
            HasDirtyBands = true;
            return;
        }

        DirtyMinRow = Math.Min(DirtyMinRow, localY);
        DirtyMaxRow = Math.Max(DirtyMaxRow, localY);
        DirtyMinCol = Math.Min(DirtyMinCol, localX);
        DirtyMaxCol = Math.Max(DirtyMaxCol, localX);
    }

    public void MarkVisualDirty(int localX, int localY)
    {
        if (!HasVisualDirty)
        {
            VisualDirtyMinRow = VisualDirtyMaxRow = localY;
            VisualDirtyMinCol = VisualDirtyMaxCol = localX;
            HasVisualDirty = true;
            return;
        }

        VisualDirtyMinRow = Math.Min(VisualDirtyMinRow, localY);
        VisualDirtyMaxRow = Math.Max(VisualDirtyMaxRow, localY);
        VisualDirtyMinCol = Math.Min(VisualDirtyMinCol, localX);
        VisualDirtyMaxCol = Math.Max(VisualDirtyMaxCol, localX);
    }

    public void MarkFullVisualDirty()
    {
        HasVisualDirty = true;
        VisualDirtyMinRow = 0;
        VisualDirtyMaxRow = Height - 1;
        VisualDirtyMinCol = 0;
        VisualDirtyMaxCol = Width - 1;
    }

    public void ClearDirtyBands()
    {
        HasDirtyBands = false;
        DirtyMinRow = Height;
        DirtyMaxRow = -1;
        DirtyMinCol = Width;
        DirtyMaxCol = -1;
    }

    public void ClearVisualDirty()
    {
        HasVisualDirty = false;
        VisualDirtyMinRow = Height;
        VisualDirtyMaxRow = -1;
        VisualDirtyMinCol = Width;
        VisualDirtyMaxCol = -1;
    }

    public IEnumerable<(int LocalX, int LocalY, PrototypeParticle Particle)> EnumerateOccupied()
    {
        for (var y = 0; y < Height; y++)
        {
            for (var x = 0; x < Width; x++)
            {
                var particle = _particles[GetIndex(x, y)];
                if (particle.TypeId != 0)
                {
                    yield return (x, y, particle);
                }
            }
        }
    }

    private int GetIndex(int localX, int localY) => (localY * Width) + localX;
}