a refactoring of some work Steve is looking at

refactored.scala

import scalaz.syntax.either._
import scalaz.syntax.optional._


def executeUpsertEntity(request: UpsertEntityRequest)
    : ErrResponse \/ UpsertEntityResponse =
  for {
    cleanRequest <- validateUpsertRequestValues(request)
    validKey <- validateCompositeKey(cleanRequest.keyValues)
    result <- executeUpsert(validKey, cleanRequst)
  } yield result


def executeUpsert
    (subjectKey: (String, String), request: ValidatedUpsertParams) =
  queryInvoker
    .performUpsert(
      request.entityType,
      subjectKey,
      request.need,
      request.agent,
      request.text,
      request.score)
    .run.run
    .leftMap { x => BadRequest(x.message) }
    .flatMap { b =>
      val err =
        InvalidReferences("No projections contained the referenced entities")
      b either UpsertEntityResponse or err
    }


private def validateUpsertRequestValues(request: UpsertEntityRequest)
    : ErrResponse \/ ValidatedUpsertParams =
  request match {
    case
        UpsertNeedAEntityRequest(
          Need_A(
            Some(GraphReference(Some(subjectType), Some(subjectKeyValues))),
            Some(need),
            Some(agent),
            Some(text),
            Some(score))) =>
      ValidatedUpsertParams(
        subjectType, subjectKeyValues, need, agent, text, score).right
    case UpsertNeedAEntityRequest(_) =>
      InvalidReferences(
          "At least one of graph reference, need, model or score was omitted")
        .left
    case _ =>
      BadRequest("Unknown entity type").left
  }


private def validateCompositeKey(keys: Map[String,String])
    : ErrResponse \/ (String,String) =
  canonicalCompositeKey(keys) \/> InvalidReferences("Invalid graph reference")