Optics at Nicecactus

AssistEvent.json

{
  "user":"szeretemacsokit",
  "sessionId":"8416525d747a48efa744f0c3ce753d76",
  "game":{
    "id":5426,
    "name": "League of Legends"
  },
  "event":{
    "name":"assist",
    "data":{
      "count":"8"
    }
  },
  "date":"2020-06-02T10:25:00.126Z"
}

DeathEvent.json

{
  "user":"szeretemacsokit",
  "sessionId":"8416525d747a48efa744f0c3ce753d76",
  "game":{
    "id":5426,
    "name": "League of Legends"
  },
  "event":{
    "name":"death",
    "data":{
      "count":"8"
    }
  },
  "date":"2020-06-02T10:25:00.126Z"
}

EmptyStringGame.json

{
  "user":"szeretemacsokit",
  "sessionId":"8416525d747a48efa744f0c3ce753d76",
  "game":{
    "id":5426,
    "name": ""
  },
  "event":{
    "name":"death",
    "data":{
      "count":"8"
    }
  },
  "date":"2020-06-02T10:25:00.126Z"
}

EmptyStringGame.scala

import cats.syntax.option._
import java.time.Instant

Envelope(
  userId = "szeretemacsokit",
  sessionId = "8416525d747a48efa744f0c3ce753d76",
  game = 
    Game(
      id = 5426,
      name = "".some
    )
  event = 
    OverwolfEvent.Event(
      name = "death",
      data = OverwolfEvent.Event.EventPayload.Death(count = 8)
    )
  date = ???
  ) 
)

Envelope.scala

final case class Envelope(
  userId: String,
  sessionId: String,
  date: Instant,
  game: Game,
  event: OverwolfEvent
)

final case class Game(
  id: Int,
  name: Option[String]
)


sealed trait OverwolfEvent
object OverwolfEvent {

  final case class Event(
    name: String,
    data: EventPayload
  ) extends OverwolfEvent

  object Event {
    sealed trait EventPayload
    object EventPayload {
      final case class Death(count: Int) extends EventPayload
      final case class Assist(count: Int) extends EventPayload
    }
  }
  
  final case class InfoUpdate(
    feature: String,
    info: InfoPayload
  ) extends OverwolfEvent
  
  object InfoUpdate {
    sealed trait InfoUpdatePayload
    object InfoUpdatePayload {

      sealed trait Kill                          extends InfoUpdatePayload
      object Kill {
        final case class Kills(kills: Int)         extends Kill
        final case class Assists(assists: Int)     extends Kill
        final case class Headshots(headshots: Int) extends Kill
      }

    }
  }
  
}

KillInfoUpdate_assists.json

{
  "user": "szeretemacsokit",
  "sessionId": "038565cf00664aecbbcc28ed1bc03abd",
  "game": {
    "id": 21640,
    "name": "Valorant"
  },
  "event": {
    "info": {
      "kill": {
        "assists": 1
      }
    },
    "feature": "kill"
  },
  "date": "2020-08-21T22:04:13.158Z"
}

KillInfoUpdate_headshots.json

{
  "user": "szeretemacsokit",
  "sessionId": "038565cf00664aecbbcc28ed1bc03abd",
  "game": {
    "id": 21640,
    "name": "Valorant"
  },
  "event": {
    "info": {
      "kill": {
        "headshots": 1
      }
    },
    "feature": "kill"
  },
  "date": "2020-08-21T22:04:13.158Z"
}

KillInfoUpdate_kills.json

{
  "user": "szeretemacsokit",
  "sessionId": "038565cf00664aecbbcc28ed1bc03abd",
  "game": {
    "id": 21640,
    "name": "Valorant"
  },
  "event": {
    "info": {
      "kill": {
        "kills": 1
      }
    },
    "feature": "kill"
  },
  "date": "2020-08-21T22:04:13.158Z"
}

Lens.scala

final case class Lens[A, B](
   get: A => B,
   set: (A, B) => A
) { self => 
 
  def compose[C](other: Lens[B, C]) =
    Lens(
     get = self.get andThen other.get, 
     set = (a, c) => self.set(a, other.set(self.get(a), c))
    )
  
  def modify(f : B => B): A => A =
    a => self.set(a, (self.get andThen f)(a)
}

RemoveEmptyGameName.scala

// original
val removeEmptyGameName : Envelope => Envelope = 
  message =>  message.copy(
    game = message.game.copy(
      name = message.game.name.filter(_.nonEmpty)
    )
  )

// with Lenses
val envelopeGameLens = 
  Lens(
    get = _.game,
    set = (envelope, nemGame) => envelope.copy(game = nemGame)
  )

val gameNameLens = 
   Lens(
     get = _.name,
     set = (game, newName) => game.copy(name = newName)
   )


val removeEmptyGameName : Envelope => Envelope = 
  (envelopeGameLens compose gameNameLens).modify(_.filter(_.nonEmpty))