using System.Numerics;
using AcDream.App.Physics;
using AcDream.App.Rendering;
using AcDream.App.Rendering.Vfx;
using AcDream.App.Streaming;
using AcDream.App.World;
using AcDream.Core.Net;
using AcDream.Core.Net.Messages;
using AcDream.Core.Physics;
using AcDream.Core.World;
using DatReaderWriter.DBObjs;

namespace AcDream.App.Tests.Physics;

public sealed class RemotePhysicsUpdaterTests
{
    [Fact]
    public void TickHidden_AppliesPositionManagerOffsetWithoutAdvancingPhysics()
    {
        var motion = new GameWindow.RemoteMotion();
        motion.Body.Position = Vector3.Zero;
        motion.Body.Orientation = Quaternion.Identity;
        motion.Body.Velocity = new Vector3(4f, 0f, 5f);
        motion.Body.Acceleration = new Vector3(0f, 0f, -9.8f);
        motion.CellId = 0x01010001u;
        motion.Interp.Enqueue(
            new Vector3(1f, 0f, 0f),
            heading: 0f,
            isMovingTo: false,
            currentBodyPosition: Vector3.Zero);
        var entity = new WorldEntity
        {
            Id = 1u,
            ServerGuid = 0x70000001u,
            SourceGfxObjOrSetupId = 0x02000001u,
            Position = Vector3.Zero,
            Rotation = Quaternion.Identity,
            MeshRefs = Array.Empty<MeshRef>(),
        };

        var updater = new RemotePhysicsUpdater(
            new PhysicsEngine(),
            (_, _) => (0.48f, 1.835f),
            (_, _, _, _) => { });
        var poses = new EntityEffectPoseRegistry();
        poses.Publish(entity, Array.Empty<Matrix4x4>());
        updater.TickHidden(motion, entity, 0.1f);
        Assert.True(poses.UpdateRoot(entity));

        Assert.InRange(motion.Body.Position.X, 0.01f, 1f);
        Assert.Equal(0f, motion.Body.Position.Z);
        Assert.Equal(new Vector3(4f, 0f, 5f), motion.Body.Velocity);
        Assert.Equal(motion.Body.Position, entity.Position);
        Assert.Equal(motion.CellId, entity.ParentCellId);
        Assert.True(poses.TryGetRootPose(entity.Id, out Matrix4x4 root));
        Assert.Equal(entity.Position, root.Translation);
    }

    [Fact]
    public void TickHidden_RunsPartArrayManagerTailWithoutAdvancingSequence()
    {
        var updater = new RemotePhysicsUpdater(
            new PhysicsEngine(),
            (_, _) => (0.48f, 1.835f),
            (_, _, _, _) => { });
        var motion = new GameWindow.RemoteMotion();
        motion.Body.Orientation = Quaternion.Identity;
        var entity = new WorldEntity
        {
            Id = 2u,
            ServerGuid = 0x70000002u,
            SourceGfxObjOrSetupId = 0x02000001u,
            Position = Vector3.Zero,
            Rotation = Quaternion.Identity,
            MeshRefs = Array.Empty<MeshRef>(),
        };
        int partArrayTailCalls = 0;

        updater.TickHidden(
            motion,
            entity,
            0.1f,
            () => partArrayTailCalls++);

        Assert.Equal(1, partArrayTailCalls);
    }

    [Fact]
    public void TickHidden_CrossCellCommitUpdatesCanonicalCellBeforeUnhide()
    {
        var engine = BuildBoundaryEngine();
        var updater = new RemotePhysicsUpdater(
            engine,
            (_, _) => (0.48f, 1.835f),
            (_, _, _, _) => { });
        var motion = new GameWindow.RemoteMotion();
        motion.Body.Position = new Vector3(191f, 10f, 50f);
        motion.Body.Orientation = Quaternion.Identity;
        motion.Body.TransientState = TransientStateFlags.Contact
                                   | TransientStateFlags.OnWalkable;
        uint canonicalCell = 0xA9B40039u;
        int canonicalWrites = 0;
        motion.BindCanonicalCell(
            () => canonicalCell,
            value =>
            {
                canonicalCell = value;
                canonicalWrites++;
            });
        motion.CellId = canonicalCell;
        canonicalWrites = 0;
        motion.Interp.Enqueue(
            new Vector3(193f, 10f, 50f),
            heading: 0f,
            isMovingTo: false,
            currentBodyPosition: motion.Body.Position);
        var entity = new WorldEntity
        {
            Id = 1u,
            ServerGuid = 0x70000002u,
            SourceGfxObjOrSetupId = 0x02000001u,
            Position = motion.Body.Position,
            Rotation = Quaternion.Identity,
            MeshRefs = Array.Empty<MeshRef>(),
        };

        updater.TickHidden(motion, entity, 2f);

        Assert.Equal(0xAAB40001u, canonicalCell);
        Assert.Equal(canonicalCell, entity.ParentCellId);
        Assert.True(canonicalWrites > 0);
        Assert.True(entity.Position.X > 192f);
    }

    [Fact]
    public void TickHidden_LandingSynchronizesRemoteAirborneState()
    {
        var engine = BuildBoundaryEngine();
        var updater = new RemotePhysicsUpdater(
            engine,
            (_, _) => (0.48f, 1.835f),
            (_, _, _, _) => { });
        var motion = new GameWindow.RemoteMotion
        {
            Airborne = true,
        };
        motion.Body.Position = new Vector3(10f, 10f, 50f);
        motion.Body.Orientation = Quaternion.Identity;
        motion.Body.TransientState = TransientStateFlags.Active;
        motion.CellId = 0xA9B40001u;
        motion.Interp.Enqueue(
            new Vector3(11f, 10f, 50f),
            heading: 0f,
            isMovingTo: false,
            currentBodyPosition: motion.Body.Position);
        var entity = new WorldEntity
        {
            Id = 3u,
            ServerGuid = 0x70000003u,
            SourceGfxObjOrSetupId = 0x02000001u,
            Position = motion.Body.Position,
            Rotation = Quaternion.Identity,
            MeshRefs = Array.Empty<MeshRef>(),
        };

        updater.TickHidden(motion, entity, 0.1f);

        Assert.True(motion.Body.InContact);
        Assert.True(motion.Body.OnWalkable);
        Assert.False(motion.Airborne);
    }

    [Fact]
    public void TickHiddenEntities_DeletionCallbackCannotAdvanceStaleSnapshotOwner()
    {
        const uint firstGuid = 0x70000011u;
        const uint secondGuid = 0x70000012u;
        var spatial = new GpuWorldState();
        spatial.AddLandblock(new LoadedLandblock(
            0x0101FFFFu,
            new LandBlock(),
            Array.Empty<WorldEntity>()));
        var live = new LiveEntityRuntime(
            spatial,
            new DelegateLiveEntityResourceLifecycle(_ => { }, _ => { }));
        BindHiddenRemote(live, firstGuid);
        BindHiddenRemote(live, secondGuid);
        Assert.Equal(2, live.SpatialRemoteMotionRuntimes.Count);

        var updater = new RemotePhysicsUpdater(
            new PhysicsEngine(),
            (_, _) => (0.48f, 1.835f),
            (_, _, _, _) => { });
        var published = new List<uint>();
        updater.TickHiddenEntities(
            live,
            localPlayerServerGuid: 0x50000001u,
            dt: 0.1f,
            entity =>
            {
                published.Add(entity.ServerGuid);
                uint other = entity.ServerGuid == firstGuid ? secondGuid : firstGuid;
                Assert.True(live.UnregisterLiveEntity(
                    new DeleteObject.Parsed(other, InstanceSequence: 1),
                    isLocalPlayer: false));
            });

        Assert.Single(published);
        Assert.Single(live.SpatialRemoteMotionRuntimes);
    }

    private static PhysicsEngine BuildBoundaryEngine()
    {
        static TerrainSurface FlatTerrain()
        {
            var heights = new byte[81];
            var table = new float[256];
            Array.Fill(table, 50f);
            return new TerrainSurface(heights, table);
        }

        var engine = new PhysicsEngine { DataCache = new PhysicsDataCache() };
        engine.AddLandblock(
            0xA9B4FFFFu,
            FlatTerrain(),
            Array.Empty<CellSurface>(),
            Array.Empty<PortalPlane>(),
            0f,
            0f);
        engine.AddLandblock(
            0xAAB4FFFFu,
            FlatTerrain(),
            Array.Empty<CellSurface>(),
            Array.Empty<PortalPlane>(),
            192f,
            0f);
        return engine;
    }

    private static void BindHiddenRemote(LiveEntityRuntime live, uint guid)
    {
        const uint cellId = 0x01010001u;
        PhysicsStateFlags state = PhysicsStateFlags.Hidden
            | PhysicsStateFlags.IgnoreCollisions;
        var position = new CreateObject.ServerPosition(
            cellId, 10f, 10f, 5f, 1f, 0f, 0f, 0f);
        var timestamps = new PhysicsTimestamps(1, 1, 1, 1, 0, 1, 0, 1, 1);
        var physics = new PhysicsSpawnData(
            RawState: (uint)state,
            Position: position,
            Movement: null,
            AnimationFrame: null,
            SetupTableId: 0x02000001u,
            MotionTableId: 0x09000001u,
            SoundTableId: null,
            PhysicsScriptTableId: null,
            Parent: null,
            Children: null,
            Scale: null,
            Friction: null,
            Elasticity: null,
            Translucency: null,
            Velocity: null,
            Acceleration: null,
            AngularVelocity: null,
            DefaultScriptType: null,
            DefaultScriptIntensity: null,
            Timestamps: timestamps);
        live.RegisterLiveEntity(new WorldSession.EntitySpawn(
            guid,
            position,
            0x02000001u,
            Array.Empty<CreateObject.AnimPartChange>(),
            Array.Empty<CreateObject.TextureChange>(),
            Array.Empty<CreateObject.SubPaletteSwap>(),
            null,
            null,
            "hidden fixture",
            null,
            null,
            0x09000001u,
            PhysicsState: (uint)state,
            InstanceSequence: 1,
            MovementSequence: 1,
            ServerControlSequence: 1,
            PositionSequence: 1,
            Physics: physics));
        WorldEntity entity = live.MaterializeLiveEntity(
            guid,
            cellId,
            id => new WorldEntity
            {
                Id = id,
                ServerGuid = guid,
                SourceGfxObjOrSetupId = 0x02000001u,
                Position = new Vector3(10f, 10f, 5f),
                Rotation = Quaternion.Identity,
                MeshRefs = Array.Empty<MeshRef>(),
                ParentCellId = cellId,
            })!;
        var remote = new GameWindow.RemoteMotion();
        remote.Body.Position = entity.Position;
        remote.Body.Orientation = entity.Rotation;
        remote.CellId = cellId;
        remote.Interp.Enqueue(
            entity.Position + Vector3.UnitX,
            heading: 0f,
            isMovingTo: false,
            currentBodyPosition: entity.Position);
        live.SetRemoteMotionRuntime(guid, remote);
    }
}