\c dcntrlized;

-- Plain-UUID user_id: drop the legacy FK (D5).
ALTER TABLE IF EXISTS keepnote.notes DROP CONSTRAINT IF EXISTS notes_user_id_fkey;

-- Re-point existing rows to auth.users by username, then drop the old table.
-- No-op on fresh DBs (the old users table never existed).
DO $$
BEGIN
    IF EXISTS (SELECT FROM pg_catalog.pg_tables WHERE schemaname='keepnote' AND tablename='users')
       AND EXISTS (SELECT FROM pg_catalog.pg_tables WHERE schemaname='auth'   AND tablename='users') THEN
        UPDATE keepnote.notes n
           SET user_id = a.id
          FROM keepnote.users old
          JOIN auth.users a ON a.username = old.username
         WHERE n.user_id = old.id;
        DROP TABLE keepnote.users;
    END IF;
END $$;