remove castling rights of exploding rooks

src/main/scala/Board.scala

@@ -100,6 +100,8 @@ case class Board(
     b3 ← b2.place(pawn.color.queen, pos)
   } yield b3
 
+  def castles: Castles = history.castles
+
   def withHistory(h: History): Board = copy(history = h)
 
   def withCastles(c: Castles) = withHistory(history withCastles c)
@@ -119,6 +121,25 @@ case class Board(
 
   def ensureCrazyData = withCrazyData(crazyData | Crazyhouse.Data.init)
 
+  def fixCastles: Board = withCastles {
+    if (variant.allowsCastling) {
+      val wkPos = kingPosOf(White)
+      val bkPos = kingPosOf(Black)
+      val wkReady = wkPos.fold(false)(_.y == 1)
+      val bkReady = bkPos.fold(false)(_.y == 8)
+      def rookReady(color: Color, kPos: Option[Pos], left: Boolean) = kPos.fold(false) { kp =>
+        actorsOf(color) exists { a =>
+          a.piece.role == Rook && a.pos.y == kp.y && (left ^ (a.pos.x > kp.x))
+        }
+      }
+      Castles(
+        whiteKingSide = castles.whiteKingSide && wkReady && rookReady(White, wkPos, false),
+        whiteQueenSide = castles.whiteQueenSide && wkReady && rookReady(White, wkPos, true),
+        blackKingSide = castles.blackKingSide && bkReady && rookReady(Black, bkPos, false),
+        blackQueenSide = castles.blackQueenSide && bkReady && rookReady(Black, bkPos, true))
+    } else Castles.none
+  }
+
   def updateHistory(f: History => History) = copy(history = f(history))
 
   def count(p: Piece): Int = pieces.values count (_ == p)

src/main/scala/Move.scala

@@ -26,29 +26,15 @@ case class Move(
       val h2 = h1.copy(lastMove = Some(toUci))
 
       // my broken castles
-      val h3 =
-        if ((piece is King) && h2.canCastle(color).any)
-          h2 withoutCastles color
-        else if (piece is Rook) (for {
-          kingPos ← after kingPosOf color
-          side ← Side.kingRookSide(kingPos, orig)
-          if h2 canCastle color on side
-        } yield h2.withoutCastle(color, side)) | h2
-        else h2
-
-      // opponent broken castles
-      val h4 = (for {
-        cPos ← capture
-        cPiece ← before(cPos)
-        if cPiece is Rook
-        kingPos ← after kingPosOf !color
-        side ← Side.kingRookSide(kingPos, cPos)
-        if h3 canCastle !color on side
-      } yield h3.withoutCastle(!color, side)) | h3
-
-      // captured king
-      if (after kingPosOf !color isDefined) h4 else h4 withoutCastles !color
-    }
+      if ((piece is King) && h2.canCastle(color).any)
+        h2 withoutCastles color
+      else if (piece is Rook) (for {
+        kingPos ← after kingPosOf color
+        side ← Side.kingRookSide(kingPos, orig)
+        if h2 canCastle color on side
+      } yield h2.withoutCastle(color, side)) | h2
+      else h2
+    } fixCastles
 
     board.variant.finalizeBoard(board, toUci, capture flatMap before.apply) updateHistory { h =>
       // Update position hashes last, only after updating the board,

src/main/scala/Situation.scala

@@ -53,6 +53,10 @@ case class Situation(board: Board, color: Color) {
   def drop(role: Role, pos: Pos): Valid[Drop] =
     board.variant.drop(this, role, pos)
 
+  def fixCastles = copy(
+    board = board fixCastles
+  )
+
   def withHistory(history: History) = copy(
     board = board withHistory history
   )

src/main/scala/format/Forsyth.scala

@@ -16,8 +16,7 @@ object Forsyth {
 
   def <<@(variant: Variant, rawSource: String): Option[Situation] = read(rawSource) { fen =>
     makeBoard(variant, fen) map { board =>
-      val fixedSource = fixCastles(variant, fen) | fen
-      val splitted = fixedSource split ' '
+      val splitted = fen split ' '
       val colorOption = splitted lift 1 flatMap (_ lift 0) flatMap Color.apply
       val situation = colorOption match {
         case Some(color)             => Situation(board, color)
@@ -41,7 +40,7 @@ object Forsyth {
           val history = History.make(lastMove, castles)
           (splitted lift 6 flatMap makeCheckCount).fold(history)(history.withCheckCount)
         }
-      }
+      } fixCastles
     }
   }
 
@@ -222,30 +221,5 @@ object Forsyth {
     }
   }
 
-  private[chess] def fixCastles(variant: Variant, fen: String): Option[String] =
-    fen.split(' ').toList match {
-      case boardStr :: color :: castlesStr :: rest if !variant.allowsCastling =>
-        Some(s"$boardStr $color - ${rest.mkString(" ")}")
-      case boardStr :: color :: castlesStr :: rest => makeBoard(variant, boardStr) map { board =>
-        val c1 = Castles(castlesStr)
-        val wkPos = board.kingPosOf(White)
-        val bkPos = board.kingPosOf(Black)
-        val wkReady = wkPos.fold(false)(_.y == 1)
-        val bkReady = bkPos.fold(false)(_.y == 8)
-        def rookReady(color: Color, kPos: Option[Pos], left: Boolean) = kPos.fold(false) { kp =>
-          board actorsOf color exists { a =>
-            a.piece.role == Rook && a.pos.y == kp.y && (left ^ (a.pos.x > kp.x))
-          }
-        }
-        val c2 = Castles(
-          whiteKingSide = c1.whiteKingSide && wkReady && rookReady(White, wkPos, false),
-          whiteQueenSide = c1.whiteQueenSide && wkReady && rookReady(White, wkPos, true),
-          blackKingSide = c1.blackKingSide && bkReady && rookReady(Black, bkPos, false),
-          blackQueenSide = c1.blackQueenSide && bkReady && rookReady(Black, bkPos, true))
-        s"$boardStr $color $c2 ${rest.mkString(" ")}"
-      }
-      case _ => None
-    }
-
   private def read[A](source: String)(f: String => A): A = f(source.replace("_", " ").trim)
 }

src/test/scala/format/ForsythTest.scala

@@ -184,7 +184,7 @@ class ForsythTest extends ChessTest {
     }
   }
   "fix impossible castle flags" should {
-    def fixCastles(fen: String) = f.fixCastles(Standard, fen)
+    def fixCastles(fen: String) = (f << fen).map(f >> _)
     "messed up" in {
       val fen = "yayyyyyyyyyyy"
       fixCastles(fen) must beNone
@@ -242,7 +242,7 @@ class ForsythTest extends ChessTest {
     "castling not allowed in variant" in {
       val fen = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
       val fix = "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w - - 0 1"
-      f.fixCastles(Antichess, fen) must beSome(fix)
+      (f <<@(Antichess, fen)).map(f >> _) must beSome(fix)
     }
   }
   "ignore impossible en passant squares" should {