package net.minecraft.util.datafix.fixes;

import com.mojang.datafixers.DSL;
import com.mojang.datafixers.DataFix;
import com.mojang.datafixers.TypeRewriteRule;
import com.mojang.datafixers.schemas.Schema;
import com.mojang.serialization.Dynamic;
import java.util.List;
import java.util.Optional;

public class LevelLegacyWorldGenSettingsFix extends DataFix {
	private static final String WORLD_GEN_SETTINGS = "WorldGenSettings";
	private static final List<String> OLD_SETTINGS_KEYS = List.of(
		"RandomSeed", "generatorName", "generatorOptions", "generatorVersion", "legacy_custom_options", "MapFeatures", "BonusChest"
	);

	public LevelLegacyWorldGenSettingsFix(final Schema outputSchema) {
		super(outputSchema, false);
	}

	@Override
	protected TypeRewriteRule makeRule() {
		return this.fixTypeEverywhereTyped(
			"LevelLegacyWorldGenSettingsFix", this.getInputSchema().getType(References.LEVEL), input -> input.update(DSL.remainderFinder(), dataTag -> {
				Dynamic<?> worldGenSettings = dataTag.get("WorldGenSettings").orElseEmptyMap();

				for (String key : OLD_SETTINGS_KEYS) {
					Optional<? extends Dynamic<?>> oldSetting = dataTag.get(key).result();
					if (oldSetting.isPresent()) {
						dataTag = dataTag.remove(key);
						worldGenSettings = worldGenSettings.set(key, (Dynamic<?>)oldSetting.get());
					}
				}

				return dataTag.set("WorldGenSettings", worldGenSettings);
			})
		);
	}
}