package net.minecraft.util.profiling.jfr.stats;

import com.mojang.datafixers.util.Pair;
import java.time.Duration;
import java.util.Comparator;
import java.util.List;

public final class IoSummary<T> {
	private final IoSummary.CountAndSize totalCountAndSize;
	private final List<Pair<T, IoSummary.CountAndSize>> largestSizeContributors;
	private final Duration recordingDuration;

	public IoSummary(Duration recordingDuration, List<Pair<T, IoSummary.CountAndSize>> entries) {
		this.recordingDuration = recordingDuration;
		this.totalCountAndSize = (IoSummary.CountAndSize)entries.stream()
			.map(Pair::getSecond)
			.reduce(new IoSummary.CountAndSize(0L, 0L), IoSummary.CountAndSize::add);
		this.largestSizeContributors = entries.stream().sorted(Comparator.comparing(Pair::getSecond, IoSummary.CountAndSize.SIZE_THEN_COUNT)).limit(10L).toList();
	}

	public double getCountsPerSecond() {
		return (double)this.totalCountAndSize.totalCount / this.recordingDuration.getSeconds();
	}

	public double getSizePerSecond() {
		return (double)this.totalCountAndSize.totalSize / this.recordingDuration.getSeconds();
	}

	public long getTotalCount() {
		return this.totalCountAndSize.totalCount;
	}

	public long getTotalSize() {
		return this.totalCountAndSize.totalSize;
	}

	public List<Pair<T, IoSummary.CountAndSize>> largestSizeContributors() {
		return this.largestSizeContributors;
	}

	public record CountAndSize(long totalCount, long totalSize) {
		static final Comparator<IoSummary.CountAndSize> SIZE_THEN_COUNT = Comparator.comparing(IoSummary.CountAndSize::totalSize)
			.thenComparing(IoSummary.CountAndSize::totalCount)
			.reversed();

		IoSummary.CountAndSize add(IoSummary.CountAndSize countAndSize) {
			return new IoSummary.CountAndSize(this.totalCount + countAndSize.totalCount, this.totalSize + countAndSize.totalSize);
		}

		public float averageSize() {
			return (float)this.totalSize / (float)this.totalCount;
		}
	}
}