package net.minecraft.world.level.chunk;

import java.util.BitSet;
import java.util.stream.Stream;
import net.minecraft.core.BlockPos;
import net.minecraft.world.level.ChunkPos;

public class CarvingMask {
	private final int minY;
	private final BitSet mask;
	private CarvingMask.Mask additionalMask = (x, y, z) -> false;

	public CarvingMask(final int height, final int minY) {
		this.minY = minY;
		this.mask = new BitSet(256 * height);
	}

	public void setAdditionalMask(final CarvingMask.Mask additionalMask) {
		this.additionalMask = additionalMask;
	}

	public CarvingMask(final long[] array, final int minY) {
		this.minY = minY;
		this.mask = BitSet.valueOf(array);
	}

	private int getIndex(final int x, final int y, final int z) {
		return x & 15 | (z & 15) << 4 | y - this.minY << 8;
	}

	public void set(final int x, final int y, final int z) {
		this.mask.set(this.getIndex(x, y, z));
	}

	public boolean get(final int x, final int y, final int z) {
		return this.additionalMask.test(x, y, z) || this.mask.get(this.getIndex(x, y, z));
	}

	public Stream<BlockPos> stream(final ChunkPos pos) {
		return this.mask.stream().mapToObj(i -> {
			int x = i & 15;
			int z = i >> 4 & 15;
			int y = i >> 8;
			return pos.getBlockAt(x, y + this.minY, z);
		});
	}

	public long[] toArray() {
		return this.mask.toLongArray();
	}

	public interface Mask {
		boolean test(int x, int y, int z);
	}
}