using System.Numerics;

namespace AcDream.Core.Vfx;

/// <summary>
/// Read-only view of the final pose used by entity-attached effects.
/// Implementations publish poses on the update/render thread after root motion,
/// animation, and equipped-child composition have completed.
/// </summary>
public interface IEntityEffectPoseSource
{
    bool TryGetRootPose(uint localEntityId, out Matrix4x4 rootWorld);

    bool TryGetPartPose(uint localEntityId, int partIndex, out Matrix4x4 partLocal);
}

/// <summary>
/// Optional update-thread notification surface for pose registries. Effect
/// consumers use this to refresh only owners whose final root, part, or cell
/// pose actually changed instead of polling every retained owner each frame.
/// </summary>
/// <remarks>
/// Notifications are synchronous and occur after the new pose is published.
/// Implementations must suppress notifications when a publish is byte-for-byte
/// equivalent to the current pose. Consumers must not mutate the pose source
/// from inside the callback.
/// </remarks>
public interface IEntityEffectPoseChangeSource
{
    event Action<uint>? EffectPoseChanged;
}

/// <summary>
/// Optional spatial companion for consumers, such as object lights, whose
/// render registration is scoped to the owner's current AC cell.
/// </summary>
public interface IEntityEffectCellSource
{
    bool TryGetCellId(uint localEntityId, out uint cellId);
}