Improve ai reverse engineering error reporting

app/Cron.scala

@@ -31,7 +31,7 @@ final class Cron(env: SystemEnv)(implicit app: Application) {
 
   spawn("game_auto_finish") { env ⇒
     env.gameRepo.candidatesToAutofinish flatMap { games ⇒
-      env.finisher outoftimes games.pp
+      env.finisher outoftimes games
     }
   }
 

chess/src/main/scala/ReverseEngineering.scala

@@ -7,29 +7,33 @@ final class ReverseEngineering(fromGame: Game, to: Board) {
 
   val from = fromGame.board
 
-  def move: Option[(Pos, Pos)] =
-    if (from.pieces == to.pieces) None else findMove
+  def move: Valid[(Pos, Pos)] = {
+    if (from.pieces == to.pieces) !!("from and to are similar") else findMove
+  } mapFail { msgs ⇒
+    ("ReverseEngineering failure: " + msgs.list mkString "\n").wrapNel
+  }
 
-  private def findMove: Option[(Pos, Pos)] =
+  private def findMove: Valid[(Pos, Pos)] =
     findMovedPieces match {
       case List((pos, piece)) ⇒ findPieceNewPos(pos, piece) map { np ⇒ (pos, np) }
       case List((pos1, piece1), (pos2, piece2)) if (piece1 is King) && (piece2 is Rook) ⇒
         findCastle(pos2) map { np ⇒ (pos1, np) }
       case List((pos1, piece1), (pos2, piece2)) if (piece1 is Rook) && (piece2 is King) ⇒
         findCastle(pos1) map { np ⇒ (pos2, np) }
-      case _ ⇒ None
+      case List((pos1, piece1), (pos2, piece2)) ⇒ !!("two moved pieces, but not a castle")
+      case Nil                                  ⇒ !!("no moved piece found")
     }
 
-  private def findCastle(rookPos: Pos): Option[Pos] = rookPos.x match {
-    case 1 ⇒ posAt(3, rookPos.y)
-    case 8 ⇒ posAt(7, rookPos.y)
-    case _ ⇒ None
+  private def findCastle(rookPos: Pos): Valid[Pos] = rookPos.x match {
+    case 1 ⇒ posAt(3, rookPos.y) toSuccess "invalid rook pos".wrapNel
+    case 8 ⇒ posAt(7, rookPos.y) toSuccess "invalid rook pos".wrapNel
+    case _ ⇒ !!("fail to find castle, rook on " + rookPos)
   }
 
-  private def findPieceNewPos(pos: Pos, piece: Piece): Option[Pos] = for {
+  private def findPieceNewPos(pos: Pos, piece: Piece): Valid[Pos] = (for {
     dests ← fromGame.situation.destinations get pos
     dest ← dests find { to(_) map (_ is piece.color) getOrElse false }
-  } yield dest
+  } yield dest) toSuccess "can not find piece new pos".wrapNel
 
   private def findMovedPieces: List[(Pos, Piece)] = {
 
@@ -43,4 +47,6 @@ final class ReverseEngineering(fromGame: Game, to: Board) {
       case (pos, piece, Some(newPiece)) if piece != newPiece ⇒ pos -> piece
     } toList
   }
+
+  private def !!(msg: String) = failure(msg.wrapNel)
 }

system/src/main/scala/Finisher.scala

@@ -57,8 +57,6 @@ final class Finisher(
     case _                           ⇒ success(io())
   }) | io()
 
-  private def !!(msg: String) = failure(msg.wrapNel)
-
   private def finish(
     game: DbGame,
     status: Status,
@@ -104,4 +102,6 @@ final class Finisher(
         _ ← historyRepo.addEntry(blackUser.username, blackElo, game.id)
       } yield ()
     } | io()
+
+  private def !!(msg: String) = failure(msg.wrapNel)
 }