src/game/java/net/minecraft/util/datafix/fixes/BlockNameFlatteningFix.java

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.datafixers.types.Type;
import com.mojang.datafixers.util.Either;
import com.mojang.datafixers.util.Pair;
import com.mojang.serialization.DynamicOps;
import java.util.Objects;
import net.minecraft.util.datafix.schemas.NamespacedSchema;

public class BlockNameFlatteningFix extends DataFix {
    public BlockNameFlatteningFix(Schema p_14897_, boolean p_14898_) {
        super(p_14897_, p_14898_);
    }

    @Override
    public TypeRewriteRule makeRule() {
        Type<?> type = this.getInputSchema().getType(References.BLOCK_NAME);
        Type<?> type1 = this.getOutputSchema().getType(References.BLOCK_NAME);
        Type<Pair<String, Either<Integer, String>>> type2 = DSL.named(References.BLOCK_NAME.typeName(), DSL.or(DSL.intType(), NamespacedSchema.namespacedString()));
        Type<Pair<String, String>> type3 = DSL.named(References.BLOCK_NAME.typeName(), NamespacedSchema.namespacedString());
        if (Objects.equals(type, type2) && Objects.equals(type1, type3)) {
            return this.fixTypeEverywhere(
                "BlockNameFlatteningFix",
                type2,
                type3,
                p_14904_ -> p_145141_ -> p_145141_.mapSecond(
                            p_145139_ -> p_145139_.map(BlockStateData::upgradeBlock, p_145143_ -> BlockStateData.upgradeBlock(NamespacedSchema.ensureNamespaced(p_145143_)))
                        )
            );
        } else {
            throw new IllegalStateException("Expected and actual types don't match.");
        }
    }
}