thea2.scala

import scala.concurrent.Future
import scala.concurrent.ExecutionContext.Implicits.global

// should fail with Error if user not found
def authorize(authToken: AuthToken): Future[User] = ???
def findPetForUser(user: User, id: UUID): Future[Option[Pet]] = ???
def addPetToUser(user: User, pet: Pet): Future[Unit] = ???

val getPetWithLogic = getPet.serverLogicRecoverErrors {
  case (authToken, id) =>
    authorize(authToken).flatMap { user =>
      findPetForUser(user, id).flatMap {
        case Some(pet) => Future.successful(pet)
        case None      => Future.failed(Error("Not found", StatusCode.NotFound))
      }
    }
}

val addPetWithLogic = addPet.serverLogicRecoverErrors {
  case (authToken, pet) =>
    authorize(authToken).flatMap { user =>
      addPetToUser(user, pet)
    }
}