package net.minecraft.client.gui.components.debug;

import java.lang.management.ManagementFactory;
import java.lang.management.MemoryMXBean;
import java.lang.management.MemoryUsage;
import java.util.List;
import java.util.Locale;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.resources.Identifier;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.chunk.LevelChunk;
import org.jspecify.annotations.Nullable;

@Environment(EnvType.CLIENT)
public class DebugEntryDetailedMemory implements DebugScreenEntry {
	private static final Identifier GROUP = Identifier.withDefaultNamespace("memory");
	private final MemoryMXBean memoryBean = ManagementFactory.getMemoryMXBean();

	@Override
	public void display(
		final DebugScreenDisplayer displayer,
		@Nullable final Level serverOrClientLevel,
		@Nullable final LevelChunk clientChunk,
		@Nullable final LevelChunk serverChunk
	) {
		displayer.addToGroup(
			GROUP, List.of(printMemoryUsage(this.memoryBean.getHeapMemoryUsage(), "heap"), printMemoryUsage(this.memoryBean.getNonHeapMemoryUsage(), "non-heap"))
		);
	}

	private static long bytesToMebibytes(final long used) {
		return used / 1024L / 1024L;
	}

	private static String printMemoryUsage(final MemoryUsage memoryUsage, final String type) {
		return String.format(
			Locale.ROOT,
			"Memory (%s): i=%03dMiB u=%03dMiB c=%03dMiB m=%03dMiB",
			type,
			bytesToMebibytes(memoryUsage.getInit()),
			bytesToMebibytes(memoryUsage.getUsed()),
			bytesToMebibytes(memoryUsage.getCommitted()),
			bytesToMebibytes(memoryUsage.getMax())
		);
	}

	@Override
	public boolean isAllowed(final boolean reducedDebugInfo) {
		return true;
	}
}