package net.minecraft.core;

import com.google.common.collect.Maps;
import com.mojang.math.MatrixUtil;
import com.mojang.math.Transformation;
import java.util.Map;
import net.minecraft.util.Util;
import org.joml.Matrix4f;
import org.joml.Quaternionf;
import org.joml.Vector3f;

public class BlockMath {
	private static final Map<Direction, Transformation> VANILLA_UV_TRANSFORM_LOCAL_TO_GLOBAL = Maps.newEnumMap(
		Map.of(
			Direction.SOUTH,
			Transformation.IDENTITY,
			Direction.EAST,
			new Transformation(null, new Quaternionf().rotateY((float) (Math.PI / 2)), null, null),
			Direction.WEST,
			new Transformation(null, new Quaternionf().rotateY((float) (-Math.PI / 2)), null, null),
			Direction.NORTH,
			new Transformation(null, new Quaternionf().rotateY((float) Math.PI), null, null),
			Direction.UP,
			new Transformation(null, new Quaternionf().rotateX((float) (-Math.PI / 2)), null, null),
			Direction.DOWN,
			new Transformation(null, new Quaternionf().rotateX((float) (Math.PI / 2)), null, null)
		)
	);
	private static final Map<Direction, Transformation> VANILLA_UV_TRANSFORM_GLOBAL_TO_LOCAL = Maps.newEnumMap(
		Util.mapValues(VANILLA_UV_TRANSFORM_LOCAL_TO_GLOBAL, Transformation::inverse)
	);

	public static Transformation blockCenterToCorner(final Transformation transform) {
		Matrix4f ret = new Matrix4f().translation(0.5F, 0.5F, 0.5F);
		ret.mul(transform.getMatrix());
		ret.translate(-0.5F, -0.5F, -0.5F);
		return new Transformation(ret);
	}

	public static Transformation blockCornerToCenter(final Transformation transform) {
		Matrix4f ret = new Matrix4f().translation(-0.5F, -0.5F, -0.5F);
		ret.mul(transform.getMatrix());
		ret.translate(0.5F, 0.5F, 0.5F);
		return new Transformation(ret);
	}

	public static Transformation getFaceTransformation(final Transformation transformation, final Direction originalSide) {
		if (MatrixUtil.isIdentity(transformation.getMatrix())) {
			return transformation;
		} else {
			Transformation faceAction = (Transformation)VANILLA_UV_TRANSFORM_LOCAL_TO_GLOBAL.get(originalSide);
			faceAction = transformation.compose(faceAction);
			Vector3f transformedNormal = faceAction.getMatrix().transformDirection(new Vector3f(0.0F, 0.0F, 1.0F));
			Direction newSide = Direction.getApproximateNearest(transformedNormal.x, transformedNormal.y, transformedNormal.z);
			return ((Transformation)VANILLA_UV_TRANSFORM_GLOBAL_TO_LOCAL.get(newSide)).compose(faceAction);
		}
	}
}