alter table public.submissions
  add column if not exists revision_type text;

do $$
begin
  if not exists (
    select 1
    from pg_constraint
    where conname = 'submissions_revision_type_check'
      and conrelid = 'public.submissions'::regclass
  ) then
    alter table public.submissions
      add constraint submissions_revision_type_check
      check (revision_type in ('fourge_error', 'client_revision'));
  end if;
end;
$$;

alter table public.submissions
  add column if not exists invoiced boolean not null default false;

alter table public.invoice_items
  add column if not exists submission_id uuid references public.submissions(id) on delete set null;