sealed trait AuthRequest[A]

case class SimpleAuth(user: String, password: String) extends AuthRequest[(String, String)]

case class BearerAuth(token: String) extends AuthRequest[String]

case class ExternalAuth(provider: String, id: UUID) extends AuthRequest[ExtAuth]

def getAuthReqData[A](req: AuthRequest[A]): IO[A] = req match {
    case SimpleAuth(user, password) => (user, password).pure[IO]
    case BearerAuth(token) => token.pure[IO]
    case ExternalAuth(provider, id) => getExtAuthFor(provider).getAuthData(id)
}