package net.minecraft.util.profiling.jfr;

import com.google.common.math.Quantiles;
import com.google.common.math.Quantiles.ScaleAndIndexes;
import it.unimi.dsi.fastutil.ints.Int2DoubleRBTreeMap;
import it.unimi.dsi.fastutil.ints.Int2DoubleSortedMap;
import it.unimi.dsi.fastutil.ints.Int2DoubleSortedMaps;
import java.util.Comparator;
import java.util.Map;
import net.minecraft.util.Util;

public class Percentiles {
	public static final ScaleAndIndexes DEFAULT_INDEXES = Quantiles.scale(100).indexes(50, 75, 90, 99);

	private Percentiles() {
	}

	public static Map<Integer, Double> evaluate(final long[] dataset) {
		return dataset.length == 0 ? Map.of() : sorted(DEFAULT_INDEXES.compute(dataset));
	}

	public static Map<Integer, Double> evaluate(final int[] dataset) {
		return dataset.length == 0 ? Map.of() : sorted(DEFAULT_INDEXES.compute(dataset));
	}

	public static Map<Integer, Double> evaluate(final double[] dataset) {
		return dataset.length == 0 ? Map.of() : sorted(DEFAULT_INDEXES.compute(dataset));
	}

	private static Map<Integer, Double> sorted(final Map<Integer, Double> percentiles) {
		Int2DoubleSortedMap sorted = Util.make(new Int2DoubleRBTreeMap(Comparator.reverseOrder()), it -> it.putAll(percentiles));
		return Int2DoubleSortedMaps.unmodifiable(sorted);
	}
}