Scala ReactiveMongo findAndUpdate placeholder for specific field

Question

I am trying to use findAndUpdate in case of duplicate records when trying to insert to mongoDB, using scala and reactiveMongo.

The first function receives a document and performs a simple insert query, if it fails with code 11000 (the code for duplicate / unique index violation error) then i am calling duplicateHandler function on it, which is as follows:

  def duplicateHandler(item: Item): Future[Unit] = {
    collection.findAndUpdate(
      selector = Json.obj(
        "companyId" -> item.companyId,
        "documentId" -> item.docuemntId
        "status" -> "Deleted"
    ),
      update = item,
      fetchNewObject = true
    ) map { res =>
      res.result[Item] getOrElse (throw DuplicateException(Json.toJson(item.metadata).toString))
      ()
    } recover {
      case _ =>
        logger.error(s"DuplicateException for ${item.transactionId}")
        throw DuplicateException(Json.toJson(item.metadata).toString)
    }
  }

This code works perfect, if an existing item arrives in the system, and its status is 'Deleted' it is being overriden by the new item that the function has recieved.

BUT, There is a field that exists on the original item which marks when it was deleted (field is called 'dateDeleted') that the new item doesn't have, And i would like the updated item to contain all the new fields + the original field of the 'deleted' item.

I wanted to use something like:

collection.findAndUpdate(
      selector = Json.obj(
        "companyId" -> item.companyId,
        "documentId" -> item.docuemntId
        "status" -> "Deleted"
    ),
      update = item.copy(dateDeleted = $dateDeleted),
      fetchNewObject = true
    )

where $dateDeleted will be a place holder for a field from the original item in the findAndUpdate query..

I tried looking for such placeholders for reactive mongo but didn't find anything like that...

1 solution is NOT sending the item itself on the 'update' parameter of findAndUpdate, but then i will have to browse through ALL the fields except 'dateDeleted' which is not something i wanna do here.