package net.minecraft.server;

import it.unimi.dsi.fastutil.objects.Object2IntLinkedOpenHashMap;
import it.unimi.dsi.fastutil.objects.Object2IntMaps;
import it.unimi.dsi.fastutil.objects.Object2IntMap.Entry;
import java.util.Queue;
import net.minecraft.util.ArrayListDeque;

public class SuppressedExceptionCollector {
	private static final int LATEST_ENTRY_COUNT = 8;
	private final Queue<SuppressedExceptionCollector.LongEntry> latestEntries = new ArrayListDeque<SuppressedExceptionCollector.LongEntry>();
	private final Object2IntLinkedOpenHashMap<SuppressedExceptionCollector.ShortEntry> entryCounts = new Object2IntLinkedOpenHashMap<>();

	private static long currentTimeMs() {
		return System.currentTimeMillis();
	}

	public synchronized void addEntry(String id, Throwable throwable) {
		long l = currentTimeMs();
		String string = throwable.getMessage();
		this.latestEntries.add(new SuppressedExceptionCollector.LongEntry(l, id, throwable.getClass(), string));

		while (this.latestEntries.size() > 8) {
			this.latestEntries.remove();
		}

		SuppressedExceptionCollector.ShortEntry shortEntry = new SuppressedExceptionCollector.ShortEntry(id, throwable.getClass());
		int i = this.entryCounts.getInt(shortEntry);
		this.entryCounts.putAndMoveToFirst(shortEntry, i + 1);
	}

	public synchronized String dump() {
		long l = currentTimeMs();
		StringBuilder stringBuilder = new StringBuilder();
		if (!this.latestEntries.isEmpty()) {
			stringBuilder.append("\n\t\tLatest entries:\n");

			for (SuppressedExceptionCollector.LongEntry longEntry : this.latestEntries) {
				stringBuilder.append("\t\t\t")
					.append(longEntry.location)
					.append(":")
					.append(longEntry.cls)
					.append(": ")
					.append(longEntry.message)
					.append(" (")
					.append(l - longEntry.timestampMs)
					.append("ms ago)")
					.append("\n");
			}
		}

		if (!this.entryCounts.isEmpty()) {
			if (stringBuilder.isEmpty()) {
				stringBuilder.append("\n");
			}

			stringBuilder.append("\t\tEntry counts:\n");

			for (Entry<SuppressedExceptionCollector.ShortEntry> entry : Object2IntMaps.fastIterable(this.entryCounts)) {
				stringBuilder.append("\t\t\t")
					.append(((SuppressedExceptionCollector.ShortEntry)entry.getKey()).location)
					.append(":")
					.append(((SuppressedExceptionCollector.ShortEntry)entry.getKey()).cls)
					.append(" x ")
					.append(entry.getIntValue())
					.append("\n");
			}
		}

		return stringBuilder.isEmpty() ? "~~NONE~~" : stringBuilder.toString();
	}

	record LongEntry(long timestampMs, String location, Class<? extends Throwable> cls, String message) {
	}

	record ShortEntry(String location, Class<? extends Throwable> cls) {
	}
}