package net.minecraft.world.flag;

import com.google.common.collect.Sets;
import com.mojang.logging.LogUtils;
import com.mojang.serialization.Codec;
import com.mojang.serialization.DataResult;
import java.util.Arrays;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Consumer;
import net.minecraft.resources.Identifier;
import org.slf4j.Logger;

public class FeatureFlagRegistry {
	private static final Logger LOGGER = LogUtils.getLogger();
	private final FeatureFlagUniverse universe;
	private final Map<Identifier, FeatureFlag> names;
	private final FeatureFlagSet allFlags;

	private FeatureFlagRegistry(final FeatureFlagUniverse universe, final FeatureFlagSet allFlags, final Map<Identifier, FeatureFlag> names) {
		this.universe = universe;
		this.names = names;
		this.allFlags = allFlags;
	}

	public boolean isSubset(final FeatureFlagSet set) {
		return set.isSubsetOf(this.allFlags);
	}

	public FeatureFlagSet allFlags() {
		return this.allFlags;
	}

	public FeatureFlagSet fromNames(final Iterable<Identifier> flagIds) {
		return this.fromNames(flagIds, flagId -> LOGGER.warn("Unknown feature flag: {}", flagId));
	}

	public FeatureFlagSet subset(final FeatureFlag... flags) {
		return FeatureFlagSet.create(this.universe, Arrays.asList(flags));
	}

	public FeatureFlagSet fromNames(final Iterable<Identifier> flagIds, final Consumer<Identifier> unknownFlags) {
		Set<FeatureFlag> flags = Sets.newIdentityHashSet();

		for (Identifier flagId : flagIds) {
			FeatureFlag flag = (FeatureFlag)this.names.get(flagId);
			if (flag == null) {
				unknownFlags.accept(flagId);
			} else {
				flags.add(flag);
			}
		}

		return FeatureFlagSet.create(this.universe, flags);
	}

	public Set<Identifier> toNames(final FeatureFlagSet set) {
		Set<Identifier> result = new HashSet();
		this.names.forEach((id, flag) -> {
			if (set.contains(flag)) {
				result.add(id);
			}
		});
		return result;
	}

	public Codec<FeatureFlagSet> codec() {
		return Identifier.CODEC.listOf().comapFlatMap(ids -> {
			Set<Identifier> unknownIds = new HashSet();
			FeatureFlagSet result = this.fromNames(ids, unknownIds::add);
			return !unknownIds.isEmpty() ? DataResult.error(() -> "Unknown feature ids: " + unknownIds, result) : DataResult.success(result);
		}, set -> List.copyOf(this.toNames(set)));
	}

	public static class Builder {
		private final FeatureFlagUniverse universe;
		private int id;
		private final Map<Identifier, FeatureFlag> flags = new LinkedHashMap();

		public Builder(final String universeId) {
			this.universe = new FeatureFlagUniverse(universeId);
		}

		public FeatureFlag createVanilla(final String name) {
			return this.create(Identifier.withDefaultNamespace(name));
		}

		public FeatureFlag create(final Identifier name) {
			if (this.id >= 64) {
				throw new IllegalStateException("Too many feature flags");
			} else {
				FeatureFlag result = new FeatureFlag(this.universe, this.id++);
				FeatureFlag previous = (FeatureFlag)this.flags.put(name, result);
				if (previous != null) {
					throw new IllegalStateException("Duplicate feature flag " + name);
				} else {
					return result;
				}
			}
		}

		public FeatureFlagRegistry build() {
			FeatureFlagSet allValues = FeatureFlagSet.create(this.universe, this.flags.values());
			return new FeatureFlagRegistry(this.universe, allValues, Map.copyOf(this.flags));
		}
	}
}