package net.minecraft.server.packs.resources;

import com.google.common.base.Stopwatch;
import com.mojang.logging.LogUtils;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.Executor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;
import net.minecraft.Util;
import net.minecraft.util.Unit;
import net.minecraft.util.profiling.Profiler;
import net.minecraft.util.profiling.ProfilerFiller;
import org.slf4j.Logger;

public class ProfiledReloadInstance extends SimpleReloadInstance<ProfiledReloadInstance.State> {
	private static final Logger LOGGER = LogUtils.getLogger();
	private final Stopwatch total = Stopwatch.createUnstarted();

	public ProfiledReloadInstance(
		ResourceManager resourceManager,
		List<PreparableReloadListener> listeners,
		Executor backgroundExecutor,
		Executor gameExecutor,
		CompletableFuture<Unit> alsoWaitedFor
	) {
		super(
			backgroundExecutor,
			gameExecutor,
			resourceManager,
			listeners,
			(preparationBarrier, resourceManagerx, preparableReloadListener, executor2, executor3) -> {
				AtomicLong atomicLong = new AtomicLong();
				AtomicLong atomicLong2 = new AtomicLong();
				CompletableFuture<Void> completableFuture = preparableReloadListener.reload(
					preparationBarrier,
					resourceManagerx,
					profiledExecutor(executor2, atomicLong, preparableReloadListener.getName()),
					profiledExecutor(executor3, atomicLong2, preparableReloadListener.getName())
				);
				return completableFuture.thenApplyAsync(void_ -> {
					LOGGER.debug("Finished reloading {}", preparableReloadListener.getName());
					return new ProfiledReloadInstance.State(preparableReloadListener.getName(), atomicLong, atomicLong2);
				}, gameExecutor);
			},
			alsoWaitedFor
		);
		this.total.start();
		this.allDone = this.allDone.thenApplyAsync(this::finish, gameExecutor);
	}

	private static Executor profiledExecutor(Executor executor, AtomicLong atomicLong, String string) {
		return runnable -> executor.execute(() -> {
			ProfilerFiller profilerFiller = Profiler.get();
			profilerFiller.push(string);
			long l = Util.getNanos();
			runnable.run();
			atomicLong.addAndGet(Util.getNanos() - l);
			profilerFiller.pop();
		});
	}

	private List<ProfiledReloadInstance.State> finish(List<ProfiledReloadInstance.State> datapoints) {
		this.total.stop();
		long l = 0L;
		LOGGER.info("Resource reload finished after {} ms", this.total.elapsed(TimeUnit.MILLISECONDS));

		for (ProfiledReloadInstance.State state : datapoints) {
			long m = TimeUnit.NANOSECONDS.toMillis(state.preparationNanos.get());
			long n = TimeUnit.NANOSECONDS.toMillis(state.reloadNanos.get());
			long o = m + n;
			String string = state.name;
			LOGGER.info("{} took approximately {} ms ({} ms preparing, {} ms applying)", string, o, m, n);
			l += n;
		}

		LOGGER.info("Total blocking time: {} ms", l);
		return datapoints;
	}

	public record State(String name, AtomicLong preparationNanos, AtomicLong reloadNanos) {
	}
}