using System.Numerics;
using AcDream.App.Rendering.Wb;
using AcDream.Core.World;
using DatReaderWriter.DBObjs;

namespace AcDream.App.Tests.Rendering.Wb;

public sealed class LandblockSpawnAdapterReadinessTests
{
    [Fact]
    public void RenderReady_WaitsForStaticAndEnvCellMeshes()
    {
        var meshes = new ReadinessMeshAdapter();
        var adapter = new LandblockSpawnAdapter(meshes);
        var entity = new WorldEntity
        {
            Id = 1,
            ServerGuid = 0,
            SourceGfxObjOrSetupId = 0x01000010u,
            Position = Vector3.Zero,
            Rotation = Quaternion.Identity,
            MeshRefs = [new MeshRef(0x01000010u, Matrix4x4.Identity)],
        };
        var landblock = new LoadedLandblock(
            0x1234FFFFu,
            new LandBlock(),
            new[] { entity });
        const ulong envCellGeometryId = 0x2_0000_1234ul;

        adapter.OnLandblockLoaded(landblock, new[] { envCellGeometryId });

        Assert.False(adapter.IsLandblockRenderReady(landblock.LandblockId));
        meshes.ReadyIds.Add(0x01000010ul);
        Assert.False(adapter.IsLandblockRenderReady(landblock.LandblockId));
        meshes.ReadyIds.Add(envCellGeometryId);
        Assert.True(adapter.IsLandblockRenderReady(landblock.LandblockId));
    }

    [Fact]
    public void RenderReady_EmptyPublishedLandblockIsReadyUntilUnload()
    {
        var meshes = new ReadinessMeshAdapter();
        var adapter = new LandblockSpawnAdapter(meshes);
        var landblock = new LoadedLandblock(
            0x1234FFFFu,
            new LandBlock(),
            Array.Empty<WorldEntity>());

        adapter.OnLandblockLoaded(landblock);

        Assert.True(adapter.IsLandblockRenderReady(landblock.LandblockId));
        adapter.OnLandblockUnloaded(landblock.LandblockId);
        Assert.False(adapter.IsLandblockRenderReady(landblock.LandblockId));
    }

    [Fact]
    public void SharedEnvCellGeometry_IsPinnedPerLandblockAndReleasedSymmetrically()
    {
        const ulong sharedGeometryId = 0x2_0000_1234ul;
        var meshes = new ReadinessMeshAdapter();
        var adapter = new LandblockSpawnAdapter(meshes);
        var first = new LoadedLandblock(
            0x1234FFFFu,
            new LandBlock(),
            Array.Empty<WorldEntity>());
        var second = new LoadedLandblock(
            0x1235FFFFu,
            new LandBlock(),
            Array.Empty<WorldEntity>());

        adapter.OnLandblockLoaded(first, new[] { sharedGeometryId, sharedGeometryId });
        adapter.OnLandblockLoaded(second, new[] { sharedGeometryId });

        Assert.Equal(2, meshes.ReferenceCounts[sharedGeometryId]);
        Assert.Equal(2, meshes.PreparedPinCalls.Count);

        adapter.OnLandblockUnloaded(first.LandblockId);
        Assert.Equal(1, meshes.ReferenceCounts[sharedGeometryId]);

        adapter.OnLandblockUnloaded(second.LandblockId);
        Assert.DoesNotContain(sharedGeometryId, meshes.ReferenceCounts);
    }

    private sealed class ReadinessMeshAdapter : IWbMeshAdapter
    {
        public HashSet<ulong> ReadyIds { get; } = new();
        public Dictionary<ulong, int> ReferenceCounts { get; } = new();
        public List<ulong> PreparedPinCalls { get; } = new();
        public void IncrementRefCount(ulong id) =>
            ReferenceCounts[id] = ReferenceCounts.GetValueOrDefault(id) + 1;
        public void PinPreparedRenderData(ulong id)
        {
            PreparedPinCalls.Add(id);
            IncrementRefCount(id);
        }
        public void DecrementRefCount(ulong id)
        {
            int count = ReferenceCounts[id] - 1;
            if (count == 0) ReferenceCounts.Remove(id);
            else ReferenceCounts[id] = count;
        }
        public bool IsRenderDataReady(ulong id) => ReadyIds.Contains(id);
    }
}