package net.minecraft.util.debug;

import java.util.Objects;
import java.util.Optional;
import net.minecraft.core.registries.BuiltInRegistries;
import net.minecraft.core.registries.Registries;
import net.minecraft.network.RegistryFriendlyByteBuf;
import net.minecraft.network.codec.ByteBufCodecs;
import net.minecraft.network.codec.StreamCodec;
import net.minecraft.util.Util;
import org.jspecify.annotations.Nullable;

public class DebugSubscription<T> {
	public static final int DOES_NOT_EXPIRE = 0;
	@Nullable
	private final StreamCodec<? super RegistryFriendlyByteBuf, T> valueStreamCodec;
	private final int expireAfterTicks;

	public DebugSubscription(@Nullable final StreamCodec<? super RegistryFriendlyByteBuf, T> valueStreamCodec, final int expireAfterTicks) {
		this.valueStreamCodec = valueStreamCodec;
		this.expireAfterTicks = expireAfterTicks;
	}

	public DebugSubscription(@Nullable final StreamCodec<? super RegistryFriendlyByteBuf, T> valueStreamCodec) {
		this(valueStreamCodec, 0);
	}

	public DebugSubscription.Update<T> packUpdate(@Nullable final T value) {
		return new DebugSubscription.Update<>(this, Optional.ofNullable(value));
	}

	public DebugSubscription.Update<T> emptyUpdate() {
		return new DebugSubscription.Update<>(this, Optional.empty());
	}

	public DebugSubscription.Event<T> packEvent(final T value) {
		return new DebugSubscription.Event<>(this, value);
	}

	public String toString() {
		return Util.getRegisteredName(BuiltInRegistries.DEBUG_SUBSCRIPTION, this);
	}

	@Nullable
	public StreamCodec<? super RegistryFriendlyByteBuf, T> valueStreamCodec() {
		return this.valueStreamCodec;
	}

	public int expireAfterTicks() {
		return this.expireAfterTicks;
	}

	public record Event<T>(DebugSubscription<T> subscription, T value) {
		public static final StreamCodec<RegistryFriendlyByteBuf, DebugSubscription.Event<?>> STREAM_CODEC = ByteBufCodecs.registry(Registries.DEBUG_SUBSCRIPTION)
			.dispatch(DebugSubscription.Event::subscription, DebugSubscription.Event::streamCodec);

		private static <T> StreamCodec<? super RegistryFriendlyByteBuf, DebugSubscription.Event<T>> streamCodec(final DebugSubscription<T> subscription) {
			return ((StreamCodec)Objects.requireNonNull(subscription.valueStreamCodec))
				.map(value -> new DebugSubscription.Event<>(subscription, (T)value), DebugSubscription.Event::value);
		}
	}

	public record Update<T>(DebugSubscription<T> subscription, Optional<T> value) {
		public static final StreamCodec<RegistryFriendlyByteBuf, DebugSubscription.Update<?>> STREAM_CODEC = ByteBufCodecs.registry(Registries.DEBUG_SUBSCRIPTION)
			.dispatch(DebugSubscription.Update::subscription, DebugSubscription.Update::streamCodec);

		private static <T> StreamCodec<? super RegistryFriendlyByteBuf, DebugSubscription.Update<T>> streamCodec(final DebugSubscription<T> subscription) {
			return ByteBufCodecs.optional((StreamCodec)Objects.requireNonNull(subscription.valueStreamCodec))
				.map(value -> new DebugSubscription.Update<>(subscription, value), DebugSubscription.Update::value);
		}
	}
}