package net.minecraft.util.datafix;

import net.minecraft.util.Mth;
import org.apache.commons.lang3.Validate;

public class PackedBitStorage {
	private static final int BIT_TO_LONG_SHIFT = 6;
	private final long[] data;
	private final int bits;
	private final long mask;
	private final int size;

	public PackedBitStorage(int bits, int size) {
		this(bits, size, new long[Mth.roundToward(size * bits, 64) / 64]);
	}

	public PackedBitStorage(int bits, int size, long[] data) {
		Validate.inclusiveBetween(1L, 32L, (long)bits);
		this.size = size;
		this.bits = bits;
		this.data = data;
		this.mask = (1L << bits) - 1L;
		int i = Mth.roundToward(size * bits, 64) / 64;
		if (data.length != i) {
			throw new IllegalArgumentException("Invalid length given for storage, got: " + data.length + " but expected: " + i);
		}
	}

	public void set(int index, int value) {
		Validate.inclusiveBetween(0L, (long)(this.size - 1), (long)index);
		Validate.inclusiveBetween(0L, this.mask, (long)value);
		int i = index * this.bits;
		int j = i >> 6;
		int k = (index + 1) * this.bits - 1 >> 6;
		int l = i ^ j << 6;
		this.data[j] = this.data[j] & ~(this.mask << l) | (value & this.mask) << l;
		if (j != k) {
			int m = 64 - l;
			int n = this.bits - m;
			this.data[k] = this.data[k] >>> n << n | (value & this.mask) >> m;
		}
	}

	public int get(int index) {
		Validate.inclusiveBetween(0L, (long)(this.size - 1), (long)index);
		int i = index * this.bits;
		int j = i >> 6;
		int k = (index + 1) * this.bits - 1 >> 6;
		int l = i ^ j << 6;
		if (j == k) {
			return (int)(this.data[j] >>> l & this.mask);
		} else {
			int m = 64 - l;
			return (int)((this.data[j] >>> l | this.data[k] << m) & this.mask);
		}
	}

	public long[] getRaw() {
		return this.data;
	}

	public int getBits() {
		return this.bits;
	}
}