drop UCI moves on takebacks

modules/game/src/main/UciMemo.scala

@@ -26,9 +26,9 @@ final class UciMemo(ttl: Duration) {
       case _           ⇒ compute(game) addEffect { set(game, _) }
     }
 
-  def delete(game: Game) {
-    // TODO figure out a best way
-    memo.put(game.id, Vector.empty)
+  def drop(game: Game, nb: Int) {
+    val current = Option(memo getIfPresent game.id) | Vector.empty
+    memo.put(game.id, current.take(current.size - nb))
   }
 
   private def compute(game: Game): Fu[Vector[String]] = for {

modules/round/src/main/Env.scala

@@ -144,7 +144,8 @@ final class Env(
   private lazy val hijack = new Hijack(HijackTimeout)
 
   private lazy val takebacker = new Takebacker(
-    messenger = messenger)
+    messenger = messenger,
+    uciMemo = uciMemo)
 
   private def notifyMove(gameId: String, fen: String, lastMove: Option[String]) {
     hub.socket.hub ! lila.socket.actorApi.Fen(gameId, fen, lastMove)

modules/round/src/main/Player.scala

@@ -31,9 +31,8 @@ private[round] final class Player(
           } yield game.update(newChessGame, move, blur) -> move).prefixFailuresWith(playerId + " - ").future flatMap {
             case ((progress, pgn), move) ⇒
               (GameRepo save progress) >>
-                PgnRepo.save(pov.gameId, pgn) >>- {
-                  if (pov.game.hasAi) uciMemo.add(pov.game, move)
-                } >>-
+              PgnRepo.save(pov.gameId, pgn) >>- 
+              (pov.game.hasAi ! uciMemo.add(pov.game, move)) >>-
                 notifyProgress(progress) >>
                 progress.game.finished.fold(
                   moveFinish(progress.game, color) map { progress.events ::: _ }, {

modules/round/src/main/Takebacker.scala

@@ -1,8 +1,10 @@
 package lila.round
 
-import lila.game.{ GameRepo, Game, PgnRepo, Pov, Rewind, Event, Progress }
+import lila.game.{ GameRepo, Game, PgnRepo, UciMemo, Pov, Rewind, Event, Progress }
 
-private[round] final class Takebacker(messenger: Messenger) {
+private[round] final class Takebacker(
+  messenger: Messenger,
+  uciMemo: UciMemo) {
 
   def yes(pov: Pov): Fu[Events] = pov match {
     case Pov(game, _) if pov.opponent.isProposingTakeback ⇒ single(game)
@@ -39,7 +41,10 @@ private[round] final class Takebacker(messenger: Messenger) {
 
   private def single(game: Game): Fu[Events] = extras(game.id) flatMap {
     case (fen, pgn) ⇒ Rewind(game, pgn, fen).future flatMap {
-      case (progress, newPgn) ⇒ PgnRepo.save(game.id, newPgn) >> save(progress)
+      case (progress, newPgn) ⇒ 
+        PgnRepo.save(game.id, newPgn) >>-
+        uciMemo.drop(game, 1)
+        save(progress) 
     }
   }
 
@@ -51,7 +56,7 @@ private[round] final class Takebacker(messenger: Messenger) {
         case (progress, newPgn) ⇒ (prog1 withGame progress.game, newPgn)
       }
       (prog2, pgn2) = second
-      _ ← PgnRepo.save(game.id, pgn2)
+      _ ← PgnRepo.save(game.id, pgn2) >>- uciMemo.drop(game, 2)
       events ← save(prog2)
     } yield events
   }