-- The original U& expression doubled its Unicode escapes, so the regex
-- interpreted code-point text as a character range and rejected normal names.
alter table public.difficulty_presets
  drop constraint difficulty_presets_name_check;
alter table public.difficulty_presets
  add constraint difficulty_presets_name_check check (
    name = btrim(name)
    and length(name) between 2 and 40
    and name !~ U&'[\0001-\001F\007F-\009F\202A-\202E\2066-\2069]'
  );

-- A PL/pgSQL CASE without ELSE raises case_not_found for every saved UUID,
-- before reaching the custom-preset lookup below it.
create or replace function public.resolve_difficulty_preset(p_id text)
returns jsonb language plpgsql stable security invoker set search_path = '' as $$
declare preset jsonb;
begin
  case p_id
    when 'easy' then
      return jsonb_build_object('id', 'easy', 'name', 'Easy', 'seconds', 180, 'zoom', true);
    when 'normal' then
      return jsonb_build_object('id', 'normal', 'name', 'Normal', 'seconds', 90, 'zoom', true);
    when 'hard' then
      return jsonb_build_object('id', 'hard', 'name', 'Hard', 'seconds', 30, 'zoom', false);
    else null;
  end case;
  select jsonb_build_object('id', p.id::text, 'name', p.name, 'seconds', p.seconds, 'zoom', p.zoom)
  into preset from public.difficulty_presets p where p.id::text = lower(p_id);
  if not found then raise exception 'Choose a saved difficulty'; end if;
  return preset;
end;
$$;