using System.Numerics;
using AcDream.Core.Physics;
using AcDream.Core.World.Cells;
using DatReaderWriter.Enums;
using DatReaderWriter.Types;
using Xunit;
using UcgCellPortal = AcDream.Core.World.Cells.CellPortal;

namespace AcDream.Core.Tests.World.Cells;

public class EnvCellTests
{
    private static EnvCell Make(Vector3 min, Vector3 max, Matrix4x4? transform = null)
    {
        var t = transform ?? Matrix4x4.Identity;
        Matrix4x4.Invert(t, out var inv);
        return new EnvCell(0xA9B40174u, t, inv, min, max,
            System.Array.Empty<UcgCellPortal>(), System.Array.Empty<uint>(),
            seenOutside: false, containmentBsp: null);
    }

    [Fact]
    public void PointInCell_NullBsp_Aabb_InsideIsTrue()
        => Assert.True(Make(new Vector3(0,0,0), new Vector3(10,10,10)).PointInCell(new Vector3(5,5,5)));

    [Fact]
    public void PointInCell_NullBsp_Aabb_OutsideIsFalse()
        => Assert.False(Make(new Vector3(0,0,0), new Vector3(10,10,10)).PointInCell(new Vector3(20,5,5)));

    [Fact]
    public void PointInCell_TransformsWorldToLocalBeforeTesting()
    {
        var c = Make(new Vector3(0,0,0), new Vector3(10,10,10), Matrix4x4.CreateTranslation(100,0,0));
        Assert.True(c.PointInCell(new Vector3(105,5,5)));
        Assert.False(c.PointInCell(new Vector3(5,5,5)));
    }

    [Fact]
    public void PointInCell_PreparedContainmentIsAuthoritative()
    {
        var graphRoot = new CellBSPNode
        {
            Type = BSPNodeType.BPIn,
            SplittingPlane = new Plane(Vector3.UnitX, -1f),
            PosNode = new CellBSPNode { Type = BSPNodeType.Leaf },
        };
        var flatRoot = new CellBSPNode
        {
            Type = BSPNodeType.Leaf,
            LeafIndex = 1,
        };
        FlatCellContainmentBsp flat =
            FlatCollisionAssetBuilder.FlattenCellContainmentBsp(flatRoot);
        var cell = new EnvCell(
            0xA9B4_0174u,
            Matrix4x4.Identity,
            Matrix4x4.Identity,
            -Vector3.One,
            Vector3.One,
            Array.Empty<UcgCellPortal>(),
            Array.Empty<uint>(),
            seenOutside: false,
            containmentBsp: new CellBSPTree { Root = graphRoot },
            flatContainmentBsp: flat);

        Assert.True(cell.PointInCell(Vector3.Zero));
        Assert.False(BSPQuery.PointInsideCellBsp(graphRoot, Vector3.Zero));
    }
}