package net.minecraft.world.level.chunk;

import java.util.Arrays;
import net.minecraft.util.Util;
import net.minecraft.util.VisibleForDebug;
import org.jspecify.annotations.Nullable;

public class DataLayer {
	public static final int LAYER_COUNT = 16;
	public static final int LAYER_SIZE = 128;
	public static final int SIZE = 2048;
	private static final int NIBBLE_SIZE = 4;
	@Nullable
	protected byte[] data;
	private int defaultValue;

	public DataLayer() {
		this(0);
	}

	public DataLayer(final int defaultValue) {
		this.defaultValue = defaultValue;
	}

	public DataLayer(final byte[] data) {
		this.data = data;
		this.defaultValue = 0;
		if (data.length != 2048) {
			throw (IllegalArgumentException)Util.pauseInIde(new IllegalArgumentException("DataLayer should be 2048 bytes not: " + data.length));
		}
	}

	public int get(final int x, final int y, final int z) {
		return this.get(getIndex(x, y, z));
	}

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

	private static int getIndex(final int x, final int y, final int z) {
		return y << 8 | z << 4 | x;
	}

	private int get(final int index) {
		if (this.data == null) {
			return this.defaultValue;
		} else {
			int position = getByteIndex(index);
			int nibble = getNibbleIndex(index);
			return this.data[position] >> 4 * nibble & 15;
		}
	}

	private void set(final int index, final int val) {
		byte[] data = this.getData();
		int position = getByteIndex(index);
		int nibble = getNibbleIndex(index);
		int mask = ~(15 << 4 * nibble);
		int valueToSet = (val & 15) << 4 * nibble;
		data[position] = (byte)(data[position] & mask | valueToSet);
	}

	private static int getNibbleIndex(final int index) {
		return index & 1;
	}

	private static int getByteIndex(final int position) {
		return position >> 1;
	}

	public void fill(final int value) {
		this.defaultValue = value;
		this.data = null;
	}

	private static byte packFilled(final int value) {
		byte packed = (byte)value;

		for (int i = 4; i < 8; i += 4) {
			packed = (byte)(packed | value << i);
		}

		return packed;
	}

	public byte[] getData() {
		if (this.data == null) {
			this.data = new byte[2048];
			if (this.defaultValue != 0) {
				Arrays.fill(this.data, packFilled(this.defaultValue));
			}
		}

		return this.data;
	}

	public DataLayer copy() {
		return this.data == null ? new DataLayer(this.defaultValue) : new DataLayer((byte[])this.data.clone());
	}

	public String toString() {
		StringBuilder builder = new StringBuilder();

		for (int i = 0; i < 4096; i++) {
			builder.append(Integer.toHexString(this.get(i)));
			if ((i & 15) == 15) {
				builder.append("\n");
			}

			if ((i & 0xFF) == 255) {
				builder.append("\n");
			}
		}

		return builder.toString();
	}

	@VisibleForDebug
	public String layerToString(final int layer) {
		StringBuilder builder = new StringBuilder();

		for (int i = 0; i < 256; i++) {
			builder.append(Integer.toHexString(this.get(i)));
			if ((i & 15) == 15) {
				builder.append("\n");
			}
		}

		return builder.toString();
	}

	public boolean isDefinitelyHomogenous() {
		return this.data == null;
	}

	public boolean isDefinitelyFilledWith(final int value) {
		return this.data == null && this.defaultValue == value;
	}

	public boolean isEmpty() {
		return this.data == null && this.defaultValue == 0;
	}
}