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

namespace AcDream.Core.Net.Messages;

/// <summary>
/// The nine retail <c>PhysicsTimeStamp</c> channels stored at the tail of a
/// <c>PhysicsDesc</c>. Field order is verbatim from <c>acclient.h:6084</c>.
/// </summary>
public readonly record struct PhysicsTimestamps(
    ushort Position,
    ushort Movement,
    ushort State,
    ushort Vector,
    ushort Teleport,
    ushort ServerControlledMove,
    ushort ForcePosition,
    ushort ObjDesc,
    ushort Instance);

/// <summary>A parent or child attachment carried by <c>PhysicsDesc</c>.</summary>
public readonly record struct PhysicsAttachment(uint Guid, uint LocationId);

/// <summary>
/// A present Movement field. The wrapper is retained even when
/// <see cref="RawData"/> is empty so callers can distinguish absent Movement
/// from an explicitly present zero-length movement block.
/// </summary>
public readonly record struct PhysicsMovementData(
    ReadOnlyMemory<byte> RawData,
    CreateObject.ServerMotionState? MotionState,
    bool? IsAutonomous);

/// <summary>
/// Immutable, lossless projection of the retail <c>PhysicsDesc</c> embedded in
/// CreateObject (0xF745). Nullable members preserve absent versus present-zero.
/// Network acceleration is retained for protocol fidelity; retail recalculates
/// normal acceleration after applying the final physics state.
/// </summary>
public readonly record struct PhysicsSpawnData(
    uint RawState,
    CreateObject.ServerPosition? Position,
    PhysicsMovementData? Movement,
    uint? AnimationFrame,
    uint? SetupTableId,
    uint? MotionTableId,
    uint? SoundTableId,
    uint? PhysicsScriptTableId,
    PhysicsAttachment? Parent,
    ReadOnlyMemory<PhysicsAttachment>? Children,
    float? Scale,
    float? Friction,
    float? Elasticity,
    float? Translucency,
    Vector3? Velocity,
    Vector3? Acceleration,
    Vector3? AngularVelocity,
    uint? DefaultScriptType,
    float? DefaultScriptIntensity,
    PhysicsTimestamps Timestamps)
{
    /// <summary>The corrected retail flag view of <see cref="RawState"/>.</summary>
    public PhysicsStateFlags State => (PhysicsStateFlags)RawState;
}