using System.Numerics;
using AcDream.Core.Meshing;
using AcDream.Core.World;
using DatReaderWriter.DBObjs;
using DatReaderWriter.Enums;
using DatReaderWriter.Types;

namespace AcDream.Core.Tests.Meshing;

public sealed class EquippedChildAttachmentTests
{
    [Fact]
    public void TryCompose_CombinesChildPlacementHoldingFrameAndAnimatedHandPart()
    {
        var parent = new Setup
        {
            HoldingLocations =
            {
                [ParentLocation.LeftHand] = new LocationType
                {
                    PartId = 1,
                    Frame = FrameAt(2, 0, 0),
                },
            },
        };
        var parentPose = new[]
        {
            new MeshRef(1, Matrix4x4.Identity),
            new MeshRef(2, Matrix4x4.CreateTranslation(10, 0, 0)),
        };
        var child = new Setup
        {
            Parts = { 0x01000001u },
            DefaultScale = { Vector3.One },
            PlacementFrames =
            {
                [Placement.LeftHand] = new AnimationFrame(1)
                {
                    Frames = { FrameAt(3, 0, 0) },
                },
            },
        };
        var template = new[] { new MeshRef(0x01000001u, Matrix4x4.Identity) };

        bool ok = EquippedChildAttachment.TryCompose(
            parent, parentPose, child, ParentLocation.LeftHand,
            Placement.LeftHand, template, 1.0f, out var result);

        Assert.True(ok);
        Assert.Equal(15f, Assert.Single(result).PartTransform.Translation.X);
    }

    [Fact]
    public void TryCompose_MissingRequestedPlacementFallsBackToDefault()
    {
        var parent = ParentWithRightHand(partId: -1, FrameAt(4, 0, 0));
        var child = new Setup
        {
            Parts = { 0x01000001u },
            PlacementFrames =
            {
                [Placement.Default] = new AnimationFrame(1)
                {
                    Frames = { FrameAt(6, 0, 0) },
                },
            },
        };

        bool ok = EquippedChildAttachment.TryCompose(
            parent, [], child, ParentLocation.RightHand,
            Placement.RightHandCombat,
            [new MeshRef(0x01000001u, Matrix4x4.Identity)],
            1.0f,
            out var result);

        Assert.True(ok);
        Assert.Equal(10f, Assert.Single(result).PartTransform.Translation.X);
    }

    [Fact]
    public void TryCompose_MissingHoldingLocationRejectsAttachment()
    {
        bool ok = EquippedChildAttachment.TryCompose(
            new Setup(), [], new Setup(), ParentLocation.RightHand,
            Placement.RightHandCombat, [], 1.0f, out var result);

        Assert.False(ok);
        Assert.Empty(result);
    }

    private static Setup ParentWithRightHand(int partId, Frame frame) => new()
    {
        HoldingLocations =
        {
            [ParentLocation.RightHand] = new LocationType
            {
                PartId = partId,
                Frame = frame,
            },
        },
    };

    private static Frame FrameAt(float x, float y, float z) => new()
    {
        Origin = new Vector3(x, y, z),
        Orientation = Quaternion.Identity,
    };
}