using System.Numerics;
using AcDream.Core.Net;
using AcDream.Core.Net.Messages;
using AcDream.Core.Physics;

namespace AcDream.App.Input;

/// <summary>
/// Serializes input-originated output from the object-phase result and the
/// periodic position report from post-inbound controller state.
/// </summary>
public sealed class LocalPlayerOutboundController
{
    private readonly IMovementTruthDiagnosticSink _diagnostic;

    internal LocalPlayerOutboundController(IMovementTruthDiagnosticSink diagnostic)
    {
        _diagnostic = diagnostic
            ?? throw new ArgumentNullException(nameof(diagnostic));
    }

    public LocalPlayerOutboundController(
        Action<string, uint, MovementResult, Vector3, uint, byte> diagnostic)
    {
        _diagnostic = new DelegateMovementTruthDiagnosticSink(diagnostic);
    }

    /// <summary>
    /// Sends input-originated movement and jump packets before inbound
    /// dispatch. Retail emits these from input/object processing rather than
    /// from <c>CommandInterpreter::UseTime</c>.
    /// </summary>
    public void SendPreNetworkActions(
        WorldSession? session,
        PlayerMovementController controller,
        MovementResult movement,
        bool hidden)
    {
        if (session is null || hidden)
            return;

        if (!controller.TryGetOutboundPosition(out Position outboundPosition))
        {
            return;
        }
        uint wireCellId = outboundPosition.ObjCellId;
        Vector3 wirePosition = outboundPosition.Frame.Origin;
        Quaternion wireRotation = outboundPosition.Frame.Orientation;

        if (movement.ShouldSendMovementEvent)
            TrySendMovement(session, controller, movement);

        if (movement.JumpExtent.HasValue && movement.JumpVelocity.HasValue)
        {
            uint sequence = session.NextGameActionSequence();
            byte[] body = JumpAction.Build(
                gameActionSequence: sequence,
                extent: movement.JumpExtent.Value,
                velocity: movement.JumpVelocity.Value,
                cellId: wireCellId,
                position: wirePosition,
                rotation: wireRotation,
                instanceSequence: session.InstanceSequence,
                serverControlSequence: session.ServerControlSequence,
                teleportSequence: session.TeleportSequence,
                forcePositionSequence: session.ForcePositionSequence);
            session.SendGameAction(body);
        }
    }

    /// <summary>
    /// Ports the position-send slot in <c>CommandInterpreter::UseTime</c>
    /// (<c>0x006B3BF0</c>), which SmartBox calls after draining inbound
    /// events. The predicate and serialized frame therefore observe any
    /// accepted ForcePosition or teleport state from this update.
    /// </summary>
    public void SendPostNetworkPosition(
        WorldSession? session,
        PlayerMovementController controller,
        bool hidden)
    {
        if (session is null || hidden)
            return;

        if (!controller.TryGetOutboundPosition(out Position position))
        {
            return;
        }
        uint wireCellId = position.ObjCellId;
        Vector3 wirePosition = position.Frame.Origin;
        Quaternion wireRotation = position.Frame.Orientation;

        if (!controller.ShouldSendPositionEvent(
                position,
                controller.ContactPlane,
                controller.SimTimeSeconds)
            || !controller.CanSendPositionEvent)
        {
            return;
        }

        MovementResult movement = controller.CapturePresentationResult();
        byte contactByte = movement.IsOnGround ? (byte)1 : (byte)0;
        uint sequence = session.NextGameActionSequence();
        byte[] body = AutonomousPosition.Build(
            gameActionSequence: sequence,
            cellId: wireCellId,
            position: wirePosition,
            rotation: wireRotation,
            instanceSequence: session.InstanceSequence,
            serverControlSequence: session.ServerControlSequence,
            teleportSequence: session.TeleportSequence,
            forcePositionSequence: session.ForcePositionSequence,
            lastContact: contactByte);
        _diagnostic.OnOutbound(
            "AP",
            sequence,
            movement,
            wirePosition,
            wireCellId,
            contactByte);
        session.SendGameAction(body);
        controller.NotePositionSent(
            position,
            controller.ContactPlane,
            controller.SimTimeSeconds);
    }

    /// <summary>
    /// Retail ForcePosition acknowledgement sent immediately after the local
    /// body is blipped. Unlike the periodic post-network sender, this bypasses
    /// the elapsed/difference predicate but still requires a valid grounded
    /// canonical frame.
    /// </summary>
    internal void SendImmediatePosition(
        WorldSession? session,
        PlayerMovementController? controller)
    {
        if (session is null
            || controller is null
            || !controller.CanSendPositionEvent)
        {
            return;
        }

        if (!controller.TryGetOutboundPosition(out Position outboundPosition))
            return;
        uint cellId = outboundPosition.ObjCellId;
        Vector3 position = outboundPosition.Frame.Origin;
        Quaternion rotation = outboundPosition.Frame.Orientation;

        uint sequence = session.NextGameActionSequence();
        byte[] body = AutonomousPosition.Build(
            gameActionSequence: sequence,
            cellId: cellId,
            position: position,
            rotation: rotation,
            instanceSequence: session.InstanceSequence,
            serverControlSequence: session.ServerControlSequence,
            teleportSequence: session.TeleportSequence,
            forcePositionSequence: session.ForcePositionSequence,
            lastContact: 1);
        session.SendGameAction(body);
        controller.NotePositionSent(
            outboundPosition,
            controller.ContactPlane,
            controller.SimTimeSeconds);
    }

    public bool TrySendMovement(
        WorldSession? session,
        PlayerMovementController? controller,
        MovementResult movement)
    {
        if (session is null || controller is null)
            return false;

        if (!controller.TryGetOutboundPosition(out Position outboundPosition))
        {
            return false;
        }
        uint wireCellId = outboundPosition.ObjCellId;
        Vector3 wirePosition = outboundPosition.Frame.Origin;
        Quaternion wireRotation = outboundPosition.Frame.Orientation;

        byte contactByte = movement.IsOnGround ? (byte)1 : (byte)0;
        RawMotionState rawMotionState = BuildRawMotionState(movement);
        uint sequence = session.NextGameActionSequence();
        byte[] body = MoveToState.Build(
            gameActionSequence: sequence,
            rawMotionState: rawMotionState,
            cellId: wireCellId,
            position: wirePosition,
            rotation: wireRotation,
            instanceSequence: session.InstanceSequence,
            serverControlSequence: session.ServerControlSequence,
            teleportSequence: session.TeleportSequence,
            forcePositionSequence: session.ForcePositionSequence,
            contact: contactByte != 0,
            standingLongjump: false);
        _diagnostic.OnOutbound(
            "MTS",
            sequence,
            movement,
            wirePosition,
            wireCellId,
            contactByte);
        session.SendGameAction(body);
        controller.NoteMovementSent(
            controller.SimTimeSeconds,
            movement.IsMouseLookMovementEvent);
        return true;
    }

    public static RawMotionState BuildRawMotionState(MovementResult movement)
    {
        HoldKey axisHoldKey = movement.IsRunning ? HoldKey.Run : HoldKey.None;
        return new RawMotionState
        {
            CurrentHoldKey = axisHoldKey,
            // CommandInterpreter::SendMovementEvent @ 0x006B4680 passes
            // CPhysicsObj::InqRawMotionState directly to MoveToStatePack.
            // RawMotionState::UnPack @ 0x0051EFC0 treats an absent style as
            // NonCombat, so this is state—not optional observer decoration.
            CurrentStyle = movement.CurrentStyle,
            ForwardCommand = movement.ForwardCommand
                ?? RawMotionState.Default.ForwardCommand,
            ForwardHoldKey = movement.ForwardCommand.HasValue
                ? axisHoldKey : HoldKey.Invalid,
            ForwardSpeed = movement.ForwardSpeed
                ?? RawMotionState.Default.ForwardSpeed,
            SidestepCommand = movement.SidestepCommand
                ?? RawMotionState.Default.SidestepCommand,
            SidestepHoldKey = movement.SidestepCommand.HasValue
                ? movement.SidestepUsesRunHold
                    ? HoldKey.Run
                    : axisHoldKey
                : HoldKey.Invalid,
            SidestepSpeed = movement.SidestepSpeed
                ?? RawMotionState.Default.SidestepSpeed,
            TurnCommand = movement.TurnCommand
                ?? RawMotionState.Default.TurnCommand,
            TurnHoldKey = movement.TurnCommand.HasValue
                ? movement.TurnUsesRunHold
                    ? HoldKey.Run
                    : axisHoldKey
                : HoldKey.Invalid,
            TurnSpeed = movement.TurnSpeed
                ?? RawMotionState.Default.TurnSpeed,
        };
    }
}