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

package net.minecraft.util.datafix.fixes;

import com.mojang.datafixers.DSL;
import com.mojang.datafixers.OpticFinder;
import com.mojang.datafixers.Typed;
import com.mojang.datafixers.schemas.Schema;
import com.mojang.datafixers.types.Type;
import com.mojang.serialization.Dynamic;

public class BlockEntityJukeboxFix extends NamedEntityFix {
    public BlockEntityJukeboxFix(Schema p_14842_, boolean p_14843_) {
        super(p_14842_, p_14843_, "BlockEntityJukeboxFix", References.BLOCK_ENTITY, "minecraft:jukebox");
    }

    @Override
    protected Typed<?> fix(Typed<?> p_14846_) {
        Type<?> type = this.getInputSchema().getChoiceType(References.BLOCK_ENTITY, "minecraft:jukebox");
        Type<?> type1 = type.findFieldType("RecordItem");
        OpticFinder<?> opticfinder = DSL.fieldFinder("RecordItem", type1);
        Dynamic<?> dynamic = p_14846_.get(DSL.remainderFinder());
        int i = dynamic.get("Record").asInt(0);
        if (i > 0) {
            dynamic.remove("Record");
            String s = ItemStackTheFlatteningFix.updateItem(ItemIdFix.getItem(i), 0);
            if (s != null) {
                Dynamic<?> dynamic1 = dynamic.emptyMap();
                dynamic1 = dynamic1.set("id", dynamic1.createString(s));
                dynamic1 = dynamic1.set("Count", dynamic1.createByte((byte)1));
                return p_14846_.set(
                        opticfinder,
                        type1.readTyped(dynamic1).result().orElseThrow(() -> new IllegalStateException("Could not create record item stack.")).getFirst()
                    )
                    .set(DSL.remainderFinder(), dynamic);
            }
        }

        return p_14846_;
    }
}