Scala convert Future[Option[Account]] to Future[Either[String, Option[Account]]] - scala

Question

I have the following methods that return futures:
db.find(uuid, accountName): Future[Option[Account]]
db.add(uuid, account): Future[Option[Account]]
I want to write a program that finds a user in the database using a future.
If not, a user entry should be added to the database.
In either case, I want to get back a Future[Either[String, Option[Account]]] object.
I am getting a compiler error when I write the following:
def add(uuid: UUID, account: Account): Future[Either[String, Option[Account]]] =
db.find(userId, account.name).map {
case None =>
db.add(userId.uuid, account).map(Right(_))
case Some(existAccount) =>
Left(s"Account already exist $existAccount")
}
Edit:
This code can`t compile with error:
Error:(77, 41) type mismatch;
found : scala.concurrent.Future[scala.util.Right[Nothing,Option[Account]]]
required: Either[String,Option[Account]]
db.add(userId, account).map(Right(_))
^
Resolved:
Solution is:
object Test extends App {
import concurrent._
import ExecutionContext.Implicits._
import duration.Duration._
type Account = String
val found = """(.+)\1""".r
def find(name: String) = name match {
case found(_*) => Future(Option(name))
case _ => Future(None)
}
def add(account: Account) = Future(Option(account * 2))
def f(account: Account): Future[Either[String, Option[Account]]] = {
find(account) flatMap {
case None => add(account) map (Right(_))
case Some(x) => Future successful Left(s"already $account")
}
}
Console println Await.result(f("bob"), Inf)
Console println Await.result(f("bobbob"), Inf)
}