package net.minecraft.util.datafix.fixes;

import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Maps;
import com.mojang.datafixers.DSL;
import com.mojang.datafixers.DataFix;
import com.mojang.datafixers.TypeRewriteRule;
import com.mojang.datafixers.schemas.Schema;
import com.mojang.datafixers.types.Type;
import com.mojang.datafixers.util.Pair;
import com.mojang.serialization.Dynamic;
import java.util.Map;
import java.util.Objects;
import java.util.Optional;

public class ReorganizePoi extends DataFix {
	public ReorganizePoi(final Schema outputSchema, final boolean changesType) {
		super(outputSchema, changesType);
	}

	@Override
	protected TypeRewriteRule makeRule() {
		Type<Pair<String, Dynamic<?>>> poiChunkType = DSL.named(References.POI_CHUNK.typeName(), DSL.remainderType());
		if (!Objects.equals(poiChunkType, this.getInputSchema().getType(References.POI_CHUNK))) {
			throw new IllegalStateException("Poi type is not what was expected.");
		} else {
			return this.fixTypeEverywhere("POI reorganization", poiChunkType, ops -> input -> input.mapSecond(ReorganizePoi::cap));
		}
	}

	private static <T> Dynamic<T> cap(Dynamic<T> input) {
		Map<Dynamic<T>, Dynamic<T>> sections = Maps.<Dynamic<T>, Dynamic<T>>newHashMap();

		for (int i = 0; i < 16; i++) {
			String key = String.valueOf(i);
			Optional<Dynamic<T>> section = input.get(key).result();
			if (section.isPresent()) {
				Dynamic<T> sectionRecords = (Dynamic<T>)section.get();
				Dynamic<T> newSection = input.createMap(ImmutableMap.of(input.createString("Records"), sectionRecords));
				sections.put(input.createString(Integer.toString(i)), newSection);
				input = input.remove(key);
			}
		}

		return input.set("Sections", input.createMap(sections));
	}
}