Example of how the ore preference getter would look

OrePreference.java

  /*
   * Ore preferences
   */
  private static Map<String,ItemStack> preferenceCache = new HashMap<>();
  public static ItemStack getPreference(String oreName, List<ItemStack> items) {
    // just stop now if we have nothing
    if(items.isEmpty()) {
      return null;
    }

    // if we found one before, use that
    if(preferenceCache.containsKey(oreName)) {
      return preferenceCache.get(oreName).copy();
    }

    // if not, try the config to choose our best option
    // start by seeing if we have a stack which matches the config
    List<ItemStack> itemList = items
        .stream()
        .filter(stack -> Config.hasPreference.contains(stack.getItem().getRegistryName().getResourceDomain()))
        .collect(ArrayList::new, ArrayList::add, ArrayList::addAll);

    if(!itemList.isEmpty()) {
      for(String mod : Config.modPreference) {
        // find the first stack matching this mod ID
        Optional<ItemStack> optional = itemList
            .stream()
            .filter(stack -> !stack.isEmpty())
            .filter(stack -> stack.getItem().getRegistryName().getResourceDomain().equals(mod))
            .findFirst();

        // if we found something, return it
        if(optional.isPresent()) {
          preferenceCache.put(oreName, optional.get());
          return optional.get().copy();
        }
      }
    }

    // nothing? just return the first item
    return items.get(0);
  }