SangrialMutation.scala

import sangria.schema._
import sangria.execution.Executor
import sangria.parser.QueryParser
import sangria.renderer.SchemaRenderer

import sangria.integration.PlayJsonSupport._

import scala.util.{Success}
import scala.concurrent.ExecutionContext.Implicits.global


case class User(email: String, loginCount: Int = 0)

object UserRepo{
  import scala.collection.mutable.{Map => MMap}
  val map = MMap[String,User](
    "[email protected]" -> User("[email protected]")
  )

  def byEmail(email: String) = map(email)
  def loginPlusPlus(email: String) = {
    val user = map(email)
    map += (email -> user.copy(loginCount = user.loginCount + 1))
    map(email)
  }
}


object SangriaMutation extends App{

  val UserObject = ObjectType("User", List[Field[Unit,User]](
    Field("email", StringType, resolve = _.value.email),
    Field("loginCount", IntType, resolve = _.value.loginCount)
  ))


  val EMAIL = Argument("email", StringType)
  val Query = ObjectType("Query", List[Field[Unit,Unit]](
    Field("byEmail", UserObject, arguments = EMAIL :: Nil, resolve = { ctx => UserRepo.byEmail(ctx arg EMAIL)})
  ))

  val MutationTopLevel = ObjectType("Mutation", List[Field[Unit,Unit]](
    Field("loginPlusPlus", UserObject, arguments = EMAIL :: Nil, resolve = { ctx => UserRepo.loginPlusPlus(ctx arg EMAIL)})
  ))

  val schema = Schema(query = Query, mutation = Some(MutationTopLevel), additionalTypes = List(UserObject))

  val Success(byEmailAst) =  QueryParser.parse("""{ byEmail(email:"[email protected]"){email,loginCount}}""")
  val Success(mutationAst) = QueryParser.parse("""mutation LoginPlusPlus { loginPlusPlus(email:"[email protected]"){loginCount}}""")


  for{
    beforeMutationResult <- Executor.execute(schema = schema, queryAst = byEmailAst)
    mutationResult <- Executor.execute(schema = schema, queryAst = mutationAst)
    afterMutationResult <- Executor.execute(schema = schema, queryAst = byEmailAst)
  } {
    println(beforeMutationResult)
    println(mutationResult)
    println(afterMutationResult)
  }


}