package net.minecraft.world.level.levelgen;

import net.minecraft.util.RandomSource;
import org.jspecify.annotations.Nullable;

public class SingleThreadedRandomSource implements BitRandomSource {
	private static final int MODULUS_BITS = 48;
	private static final long MODULUS_MASK = 281474976710655L;
	private static final long MULTIPLIER = 25214903917L;
	private static final long INCREMENT = 11L;
	private long seed;
	@Nullable
	private MarsagliaPolarGaussian gaussianSource;

	public SingleThreadedRandomSource(final long seed) {
		this.setSeed(seed);
	}

	@Override
	public RandomSource fork() {
		return new SingleThreadedRandomSource(this.nextLong());
	}

	@Override
	public PositionalRandomFactory forkPositional() {
		return new LegacyRandomSource.LegacyPositionalRandomFactory(this.nextLong());
	}

	@Override
	public void setSeed(final long seed) {
		this.seed = (seed ^ 25214903917L) & 281474976710655L;
		if (this.gaussianSource != null) {
			this.gaussianSource.reset();
		}
	}

	@Override
	public int next(final int bits) {
		long newSeed = this.seed * 25214903917L + 11L & 281474976710655L;
		this.seed = newSeed;
		return (int)(newSeed >> 48 - bits);
	}

	@Override
	public double nextGaussian() {
		if (this.gaussianSource == null) {
			this.gaussianSource = new MarsagliaPolarGaussian(this);
		}

		return this.gaussianSource.nextGaussian();
	}
}