using Sand.Core;

namespace Sand.ChunkPrototype;

public sealed partial class PrototypeSparseSandAdapter
{
    private void ApplyHeatEmission(int x, int y, float amount)
    {
        AdjustTemperatureAt(x, y, amount * 0.08f);
        AdjustTemperatureAt(x - 1, y, amount * 0.02f);
        AdjustTemperatureAt(x + 1, y, amount * 0.02f);
        AdjustTemperatureAt(x, y - 1, amount * 0.02f);
        AdjustTemperatureAt(x, y + 1, amount * 0.02f);
    }

    private void ApplyTemperatureDiffusion(int x, int y, PrototypeParticle particle)
    {
        if (!TryGetCellPage(x, y, out _, out var page, out var localX, out var localY))
        {
            return;
        }

        var localTemperature = page.GetTemperature(localX, localY);
        var airDelta = localTemperature - _ambientTemperature;
        if (MathF.Abs(airDelta) > 0.5f)
        {
            var minTransfer = Math.Min(airDelta * -0.5f, airDelta * 0.5f);
            var maxTransfer = Math.Max(airDelta * -0.5f, airDelta * 0.5f);
            var transfer = Math.Clamp(
                airDelta * 0.05f * particle.AmbientCoolingMultiplier / MathF.Max(0.1f, particle.Conductivity <= 0f ? 1f : particle.Conductivity),
                minTransfer,
                maxTransfer);
            page.SetTemperature(localX, localY, localTemperature - transfer);
            localTemperature -= transfer;
        }

        DiffuseBetween(x, y, x + 1, y, particle, localTemperature);
        DiffuseBetween(x, y, x, y + 1, particle, localTemperature);
    }

    private void AdjustTemperatureAt(int x, int y, float delta)
    {
        if (!TryGetCellPage(x, y, out _, out var page, out var localX, out var localY))
        {
            return;
        }

        page.SetTemperature(localX, localY, page.GetTemperature(localX, localY) + delta);
    }

    private void DiffuseBetween(int x, int y, int nx, int ny, PrototypeParticle particle, float localTemperature)
    {
        if (!TryGetCellPage(x, y, out _, out var sourcePage, out var sourceLocalX, out var sourceLocalY) ||
            !TryGetCellPage(nx, ny, out _, out var targetPage, out var targetLocalX, out var targetLocalY))
        {
            return;
        }

        var neighborParticle = targetPage[targetLocalX, targetLocalY];
        if (neighborParticle.TypeId == 0)
        {
            return;
        }

        var neighborTemperature = targetPage.GetTemperature(targetLocalX, targetLocalY);
        var delta = localTemperature - neighborTemperature;
        if (MathF.Abs(delta) <= 0.5f)
        {
            return;
        }

        var sourceConductivity = MathF.Max(particle.Conductivity, 0.1f);
        var targetConductivity = MathF.Max(neighborParticle.Conductivity, 0.1f);
        var minTransfer = Math.Min(delta * -0.5f, delta * 0.5f);
        var maxTransfer = Math.Max(delta * -0.5f, delta * 0.5f);
        var transfer = Math.Clamp(
            delta * ((sourceConductivity + targetConductivity) * 0.5f) * 0.1f * particle.NeighborHeatTransferMultiplier,
            minTransfer,
            maxTransfer);
        sourcePage.SetTemperature(sourceLocalX, sourceLocalY, localTemperature - transfer);
        targetPage.SetTemperature(targetLocalX, targetLocalY, neighborTemperature + transfer);
    }
}