using UnityEngine;
using UnityEngine.Animations;
using UnityEngine.Animations.Rigging;

namespace LibMMD.Unity3D.Animation
{
    // Retained for source compatibility. Runtime IK is evaluated once in Poser before physics.
    internal struct MmdTwoBoneIkJob : IAnimationJob
    {
        public ReadWriteTransformHandle Root;
        public ReadWriteTransformHandle Mid;
        public ReadWriteTransformHandle Tip;
        public ReadOnlyTransformHandle Target;
        public ReadOnlyTransformHandle Hint;
        public AffineTransform TargetOffset;
        public float Weight;
        public float PositionWeight;
        public float RotationWeight;
        public float HintWeight;

        public void ProcessRootMotion(AnimationStream stream) { }

        public void ProcessAnimation(AnimationStream stream)
        {
            var weight = Mathf.Clamp01(Weight);
            if (weight <= 0f) return;
            AnimationRuntimeUtils.SolveTwoBoneIK(stream, Root, Mid, Tip, Target, Hint,
                Mathf.Clamp01(PositionWeight) * weight,
                Mathf.Clamp01(RotationWeight) * weight,
                Mathf.Clamp01(HintWeight) * weight, TargetOffset);
        }
    }
}