using AcDream.Core.Rendering.Wb;

namespace AcDream.Core.Tests.Rendering.Wb;

public sealed class EnvCellGeometryIdentityTests
{
    [Fact]
    public void Compute_EmptySurfaces_MatchesExtractedWorldBuilderValue()
    {
        Assert.Equal(
            0x2_0000_47D6UL,
            EnvCellGeometryIdentity.Compute(0x42, 7, Array.Empty<ushort>()));
    }

    [Fact]
    public void Compute_OrderedSurfaces_MatchesExtractedWorldBuilderValue()
    {
        Assert.Equal(
            0x2_20A7_A46CUL,
            EnvCellGeometryIdentity.Compute(0x42, 7, new ushort[] { 1, 2, 3 }));
    }

    [Fact]
    public void Compute_SurfaceOrderIsPartOfIdentity()
    {
        var forward = EnvCellGeometryIdentity.Compute(1, 1, new ushort[] { 10, 20 });
        var reverse = EnvCellGeometryIdentity.Compute(1, 1, new ushort[] { 20, 10 });

        Assert.NotEqual(forward, reverse);
    }

    [Fact]
    public void Compute_AlwaysUsesDeduplicatedGeometryNamespace()
    {
        var id = EnvCellGeometryIdentity.Compute(
            uint.MaxValue,
            ushort.MaxValue,
            new ushort[] { ushort.MaxValue, ushort.MaxValue });

        Assert.NotEqual(0UL, id & 0x2_0000_0000UL);
    }
}