package net.minecraft.util.datafix.fixes;

import com.mojang.datafixers.DataFix;
import com.mojang.datafixers.DataFixUtils;
import com.mojang.datafixers.OpticFinder;
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 net.minecraft.util.Util;

public class StructureSettingsFlattenFix extends DataFix {
	public StructureSettingsFlattenFix(final Schema outputSchema) {
		super(outputSchema, false);
	}

	@Override
	protected TypeRewriteRule makeRule() {
		Type<?> worldGenSettingsType = this.getInputSchema().getType(References.WORLD_GEN_SETTINGS);
		OpticFinder<?> dimensions = worldGenSettingsType.findField("dimensions");
		return this.fixTypeEverywhereTyped(
			"StructureSettingsFlatten",
			worldGenSettingsType,
			input -> input.updateTyped(
				dimensions,
				typed -> Util.writeAndReadTypedOrThrow(typed, dimensions.type(), serialized -> serialized.updateMapValues(StructureSettingsFlattenFix::fixDimension))
			)
		);
	}

	private static Pair<Dynamic<?>, Dynamic<?>> fixDimension(final Pair<Dynamic<?>, Dynamic<?>> entry) {
		Dynamic<?> dimension = entry.getSecond();
		return Pair.of(
			entry.getFirst(), dimension.update("generator", g -> g.update("settings", s -> s.update("structures", StructureSettingsFlattenFix::fixStructures)))
		);
	}

	private static Dynamic<?> fixStructures(final Dynamic<?> input) {
		Dynamic<?> structures = input.get("structures")
			.orElseEmptyMap()
			.updateMapValues(p -> p.mapSecond(s -> s.set("type", input.createString("minecraft:random_spread"))));
		return DataFixUtils.orElse(
			input.get("stronghold")
				.result()
				.map(stronghold -> structures.set("minecraft:stronghold", stronghold.set("type", input.createString("minecraft:concentric_rings")))),
			structures
		);
	}
}