using System.Numerics;
using AcDream.App.Rendering.Vfx;
using AcDream.Core.Vfx;

namespace AcDream.App.Tests.Rendering.Vfx;

public sealed class ParticleVisibilityControllerTests
{
    [Fact]
    public void CompletedRetailViewFeedsNextParticleUpdate()
    {
        var particles = new ParticleSystem(new EmitterDescRegistry(), new Random(1));
        int handle = particles.SpawnEmitter(
            new EmitterDesc
            {
                DatId = 0x32000001u,
                Type = ParticleType.Still,
                MaxDegradeDistance = 100f,
                MaxParticles = 1,
                InitialParticles = 1,
                LifetimeMin = 10f,
                LifetimeMax = 10f,
            },
            Vector3.Zero,
            attachedObjectId: 99u);
        particles.UpdateEmitterOwnerCell(handle, 0x01010001u);
        var controller = new ParticleVisibilityController();

        controller.BeginFrame(Vector3.Zero);
        controller.UseWorldView();
        controller.MarkVisibleCells(new HashSet<uint> { 0x01010001u });
        controller.CompleteFrame();
        controller.Apply(particles, 1f);

        Assert.True(Assert.Single(particles.EnumerateEmitters()).ViewEligible);
        Assert.Equal(handle, Assert.Single(particles.EnumerateEmitters()).Handle);
    }

    [Fact]
    public void UnresolvedFramePublishesEmptyWorldView()
    {
        var particles = new ParticleSystem(new EmitterDescRegistry(), new Random(1));
        int handle = particles.SpawnEmitter(
            new EmitterDesc
            {
                DatId = 0x32000002u,
                Type = ParticleType.Still,
                MaxDegradeDistance = 100f,
                MaxParticles = 1,
            },
            Vector3.Zero,
            attachedObjectId: 42u);
        particles.UpdateEmitterOwnerCell(handle, 0x01010001u);
        var controller = new ParticleVisibilityController();

        controller.BeginFrame(Vector3.Zero);
        controller.UseWorldView();
        controller.CompleteFrame();
        controller.Apply(particles, 1f);
        Assert.False(Assert.Single(particles.EnumerateEmitters()).ViewEligible);

        controller.BeginFrame(Vector3.Zero);
        controller.CompleteFrame();
        controller.Apply(particles, 1f);
        Assert.False(Assert.Single(particles.EnumerateEmitters()).ViewEligible);
    }
}