package net.minecraft.client.animation;

import net.minecraft.client.model.geom.ModelPart;
import net.minecraft.util.Mth;
import org.joml.Vector3f;
import org.joml.Vector3fc;

public record AnimationChannel(AnimationChannel.Target target, Keyframe... keyframes) {
	public interface Interpolation {
		Vector3f apply(final Vector3f vector, final float alpha, final Keyframe[] keyframes, final int prev, final int next, final float targetScale);
	}

	public static class Interpolations {
		public static final AnimationChannel.Interpolation LINEAR = (vector, alpha, keyframes, prev, next, targetScale) -> {
			Vector3fc point0 = keyframes[prev].postTarget();
			Vector3fc point1 = keyframes[next].preTarget();
			return point0.lerp(point1, alpha, vector).mul(targetScale);
		};
		public static final AnimationChannel.Interpolation CATMULLROM = (vector, alpha, keyframes, prev, next, targetScale) -> {
			Vector3fc point0 = keyframes[Math.max(0, prev - 1)].postTarget();
			Vector3fc point1 = keyframes[prev].postTarget();
			Vector3fc point2 = keyframes[next].postTarget();
			Vector3fc point3 = keyframes[Math.min(keyframes.length - 1, next + 1)].postTarget();
			vector.set(
				Mth.catmullrom(alpha, point0.x(), point1.x(), point2.x(), point3.x()) * targetScale,
				Mth.catmullrom(alpha, point0.y(), point1.y(), point2.y(), point3.y()) * targetScale,
				Mth.catmullrom(alpha, point0.z(), point1.z(), point2.z(), point3.z()) * targetScale
			);
			return vector;
		};
	}

	public interface Target {
		void apply(final ModelPart animationBone, final Vector3f target);
	}

	public static class Targets {
		public static final AnimationChannel.Target POSITION = ModelPart::offsetPos;
		public static final AnimationChannel.Target ROTATION = ModelPart::offsetRotation;
		public static final AnimationChannel.Target SCALE = ModelPart::offsetScale;
	}
}