refactor: migrate GameController to GameContext (signatures only)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

modules/core/src/main/scala/de/nowchess/chess/Main.scala

@@ -1,10 +1,11 @@
 package de.nowchess.chess
 
-import de.nowchess.api.board.{Board, Color}
+import de.nowchess.api.board.Color
 import de.nowchess.chess.controller.GameController
+import de.nowchess.chess.logic.GameContext
 
 object Main {
   def main(args: Array[String]): Unit =
     println("NowChess TUI — type moves in coordinate notation (e.g. e2e4). Type 'quit' to exit.")
-    GameController.gameLoop(Board.initial, Color.White)
+    GameController.gameLoop(GameContext.initial, Color.White)
 }

modules/core/src/main/scala/de/nowchess/chess/controller/GameController.scala

@@ -11,15 +11,15 @@ import de.nowchess.chess.view.Renderer
 
 sealed trait MoveResult
 object MoveResult:
-  case object Quit                                                                    extends MoveResult
-  case class  InvalidFormat(raw: String)                                              extends MoveResult
-  case object NoPiece                                                                 extends MoveResult
-  case object WrongColor                                                              extends MoveResult
-  case object IllegalMove                                                             extends MoveResult
-  case class  Moved(newBoard: Board, captured: Option[Piece], newTurn: Color)        extends MoveResult
-  case class  MovedInCheck(newBoard: Board, captured: Option[Piece], newTurn: Color) extends MoveResult
-  case class  Checkmate(winner: Color)                                                extends MoveResult
-  case object Stalemate                                                               extends MoveResult
+  case object Quit                                                                       extends MoveResult
+  case class  InvalidFormat(raw: String)                                                extends MoveResult
+  case object NoPiece                                                                   extends MoveResult
+  case object WrongColor                                                                extends MoveResult
+  case object IllegalMove                                                               extends MoveResult
+  case class  Moved(newCtx: GameContext, captured: Option[Piece], newTurn: Color)      extends MoveResult
+  case class  MovedInCheck(newCtx: GameContext, captured: Option[Piece], newTurn: Color) extends MoveResult
+  case class  Checkmate(winner: Color)                                                  extends MoveResult
+  case object Stalemate                                                                 extends MoveResult
 
 // ---------------------------------------------------------------------------
 // Controller
@@ -27,10 +27,10 @@ object MoveResult:
 
 object GameController:
 
-  /** Pure function: interprets one raw input line against the current board state.
+  /** Pure function: interprets one raw input line against the current game context.
    *  Has no I/O side effects — all output must be handled by the caller.
    */
-  def processMove(board: Board, turn: Color, raw: String): MoveResult =
+  def processMove(ctx: GameContext, turn: Color, raw: String): MoveResult =
     raw.trim match
       case "quit" | "q" =>
         MoveResult.Quit
@@ -39,61 +39,62 @@ object GameController:
           case None =>
             MoveResult.InvalidFormat(trimmed)
           case Some((from, to)) =>
-            board.pieceAt(from) match
+            ctx.board.pieceAt(from) match
               case None =>
                 MoveResult.NoPiece
               case Some(piece) if piece.color != turn =>
                 MoveResult.WrongColor
               case Some(_) =>
-                if !MoveValidator.isLegal(board, from, to) then
+                if !MoveValidator.isLegal(ctx, from, to) then
                   MoveResult.IllegalMove
                 else
-                  val (newBoard, captured) = board.withMove(from, to)
-                  GameRules.gameStatus(GameContext(newBoard), turn.opposite) match
-                    case PositionStatus.Normal  => MoveResult.Moved(newBoard, captured, turn.opposite)
-                    case PositionStatus.InCheck => MoveResult.MovedInCheck(newBoard, captured, turn.opposite)
+                  val (newBoard, captured) = ctx.board.withMove(from, to)
+                  val newCtx = ctx.copy(board = newBoard)
+                  GameRules.gameStatus(newCtx, turn.opposite) match
+                    case PositionStatus.Normal  => MoveResult.Moved(newCtx, captured, turn.opposite)
+                    case PositionStatus.InCheck => MoveResult.MovedInCheck(newCtx, captured, turn.opposite)
                     case PositionStatus.Mated   => MoveResult.Checkmate(turn)
                     case PositionStatus.Drawn   => MoveResult.Stalemate
 
   /** Thin I/O shell: renders the board, reads a line, delegates to processMove,
    *  prints the outcome, and recurses until the game ends.
    */
-  def gameLoop(board: Board, turn: Color): Unit =
+  def gameLoop(ctx: GameContext, turn: Color): Unit =
     println()
-    print(Renderer.render(board))
+    print(Renderer.render(ctx.board))
     println(s"${turn.label}'s turn. Enter move: ")
     val input = Option(StdIn.readLine()).getOrElse("quit").trim
-    processMove(board, turn, input) match
+    processMove(ctx, turn, input) match
       case MoveResult.Quit =>
         println("Game over. Goodbye!")
       case MoveResult.InvalidFormat(raw) =>
         println(s"Invalid move format '$raw'. Use coordinate notation, e.g. e2e4.")
-        gameLoop(board, turn)
+        gameLoop(ctx, turn)
       case MoveResult.NoPiece =>
         println(s"No piece on ${Parser.parseMove(input).map(_._1).fold("?")(_.toString)}.")
-        gameLoop(board, turn)
+        gameLoop(ctx, turn)
       case MoveResult.WrongColor =>
         println(s"That is not your piece.")
-        gameLoop(board, turn)
+        gameLoop(ctx, turn)
       case MoveResult.IllegalMove =>
         println(s"Illegal move.")
-        gameLoop(board, turn)
-      case MoveResult.Moved(newBoard, captured, newTurn) =>
+        gameLoop(ctx, turn)
+      case MoveResult.Moved(newCtx, captured, newTurn) =>
         val prevTurn = newTurn.opposite
         captured.foreach: cap =>
           val toSq = Parser.parseMove(input).map(_._2).fold("?")(_.toString)
           println(s"${prevTurn.label} captures ${cap.color.label} ${cap.pieceType.label} on $toSq")
-        gameLoop(newBoard, newTurn)
-      case MoveResult.MovedInCheck(newBoard, captured, newTurn) =>
+        gameLoop(newCtx, newTurn)
+      case MoveResult.MovedInCheck(newCtx, captured, newTurn) =>
         val prevTurn = newTurn.opposite
         captured.foreach: cap =>
           val toSq = Parser.parseMove(input).map(_._2).fold("?")(_.toString)
           println(s"${prevTurn.label} captures ${cap.color.label} ${cap.pieceType.label} on $toSq")
         println(s"${newTurn.label} is in check!")
-        gameLoop(newBoard, newTurn)
+        gameLoop(newCtx, newTurn)
       case MoveResult.Checkmate(winner) =>
         println(s"Checkmate! ${winner.label} wins.")
-        gameLoop(Board.initial, Color.White)
+        gameLoop(GameContext.initial, Color.White)
       case MoveResult.Stalemate =>
         println("Stalemate! The game is a draw.")
-        gameLoop(Board.initial, Color.White)
+        gameLoop(GameContext.initial, Color.White)

modules/core/src/test/scala/de/nowchess/chess/controller/GameControllerTest.scala

@@ -1,6 +1,8 @@
 package de.nowchess.chess.controller
 
 import de.nowchess.api.board.*
+import de.nowchess.api.game.CastlingRights
+import de.nowchess.chess.logic.{GameContext, CastleSide}
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
@@ -9,7 +11,7 @@ import java.io.ByteArrayInputStream
 class GameControllerTest extends AnyFunSuite with Matchers:
 
   private def sq(f: File, r: Rank): Square = Square(f, r)
-  private val initial = Board.initial
+  private val initial = GameContext.initial
 
   // ──── processMove ────────────────────────────────────────────────────
 
@@ -39,24 +41,24 @@ class GameControllerTest extends AnyFunSuite with Matchers:
 
   test("processMove: legal pawn move returns Moved with updated board and flipped turn"):
     GameController.processMove(initial, Color.White, "e2e4") match
-      case MoveResult.Moved(newBoard, captured, newTurn) =>
-        newBoard.pieceAt(sq(File.E, Rank.R4)) shouldBe Some(Piece.WhitePawn)
-        newBoard.pieceAt(sq(File.E, Rank.R2)) shouldBe None
+      case MoveResult.Moved(newCtx, captured, newTurn) =>
+        newCtx.board.pieceAt(sq(File.E, Rank.R4)) shouldBe Some(Piece.WhitePawn)
+        newCtx.board.pieceAt(sq(File.E, Rank.R2)) shouldBe None
         captured shouldBe None
         newTurn shouldBe Color.Black
       case other => fail(s"Expected Moved, got $other")
 
   test("processMove: legal capture returns Moved with the captured piece"):
-    val captureBoard = Board(Map(
+    val captureCtx = GameContext(Board(Map(
       sq(File.E, Rank.R5) -> Piece.WhitePawn,
       sq(File.D, Rank.R6) -> Piece.BlackPawn,
       sq(File.H, Rank.R1) -> Piece.BlackKing,
       sq(File.H, Rank.R8) -> Piece.WhiteKing
-    ))
-    GameController.processMove(captureBoard, Color.White, "e5d6") match
-      case MoveResult.Moved(newBoard, captured, newTurn) =>
+    )))
+    GameController.processMove(captureCtx, Color.White, "e5d6") match
+      case MoveResult.Moved(newCtx, captured, newTurn) =>
         captured shouldBe Some(Piece.BlackPawn)
-        newBoard.pieceAt(sq(File.D, Rank.R6)) shouldBe Some(Piece.WhitePawn)
+        newCtx.board.pieceAt(sq(File.D, Rank.R6)) shouldBe Some(Piece.WhitePawn)
         newTurn shouldBe Color.Black
       case other => fail(s"Expected Moved, got $other")
 
@@ -68,33 +70,33 @@ class GameControllerTest extends AnyFunSuite with Matchers:
 
   test("gameLoop: 'quit' exits cleanly without exception"):
     withInput("quit\n"):
-      GameController.gameLoop(Board.initial, Color.White)
+      GameController.gameLoop(GameContext.initial, Color.White)
 
   test("gameLoop: EOF (null readLine) exits via quit fallback"):
     withInput(""):
-      GameController.gameLoop(Board.initial, Color.White)
+      GameController.gameLoop(GameContext.initial, Color.White)
 
   test("gameLoop: invalid format prints message and recurses until quit"):
     withInput("badmove\nquit\n"):
-      GameController.gameLoop(Board.initial, Color.White)
+      GameController.gameLoop(GameContext.initial, Color.White)
 
   test("gameLoop: NoPiece prints message and recurses until quit"):
     // E3 is empty in the initial position
     withInput("e3e4\nquit\n"):
-      GameController.gameLoop(Board.initial, Color.White)
+      GameController.gameLoop(GameContext.initial, Color.White)
 
   test("gameLoop: WrongColor prints message and recurses until quit"):
     // E7 has a Black pawn; it is White's turn
     withInput("e7e6\nquit\n"):
-      GameController.gameLoop(Board.initial, Color.White)
+      GameController.gameLoop(GameContext.initial, Color.White)
 
   test("gameLoop: IllegalMove prints message and recurses until quit"):
     withInput("e2e5\nquit\n"):
-      GameController.gameLoop(Board.initial, Color.White)
+      GameController.gameLoop(GameContext.initial, Color.White)
 
   test("gameLoop: legal non-capture move recurses with new board then quits"):
     withInput("e2e4\nquit\n"):
-      GameController.gameLoop(Board.initial, Color.White)
+      GameController.gameLoop(GameContext.initial, Color.White)
 
   test("gameLoop: capture move prints capture message then recurses and quits"):
     val captureBoard = Board(Map(
@@ -104,7 +106,7 @@ class GameControllerTest extends AnyFunSuite with Matchers:
       sq(File.H, Rank.R8) -> Piece.WhiteKing
     ))
     withInput("e5d6\nquit\n"):
-      GameController.gameLoop(captureBoard, Color.White)
+      GameController.gameLoop(GameContext(captureBoard), Color.White)
 
   // ──── helpers ────────────────────────────────────────────────────────
 
@@ -118,12 +120,12 @@ class GameControllerTest extends AnyFunSuite with Matchers:
   test("processMove: legal move that delivers check returns MovedInCheck"):
     // White Ra1, Ka3; Black Kh8 — White plays Ra1-Ra8, Ra8 attacks rank 8 putting Kh8 in check
     // Kh8 can escape to g7/g8/h7 so this is InCheck, not Mated
-    val b = Board(Map(
+    val ctx = GameContext(Board(Map(
       sq(File.A, Rank.R1) -> Piece.WhiteRook,
       sq(File.C, Rank.R3) -> Piece.WhiteKing,
       sq(File.H, Rank.R8) -> Piece.BlackKing
-    ))
-    GameController.processMove(b, Color.White, "a1a8") match
+    )))
+    GameController.processMove(ctx, Color.White, "a1a8") match
       case MoveResult.MovedInCheck(_, _, newTurn) => newTurn shouldBe Color.Black
       case other => fail(s"Expected MovedInCheck, got $other")
 
@@ -131,24 +133,24 @@ class GameControllerTest extends AnyFunSuite with Matchers:
     // White Qa1, Ka6; Black Ka8 — White plays Qa1-Qh8 (diagonal a1→h8)
     // After Qh8: White Qh8 + Ka6 vs Black Ka8 = checkmate (spec-verified position)
     // Qa1 does NOT currently attack Ka8 — path along file A is blocked by Ka6
-    val b = Board(Map(
+    val ctx = GameContext(Board(Map(
       sq(File.A, Rank.R1) -> Piece.WhiteQueen,
       sq(File.A, Rank.R6) -> Piece.WhiteKing,
       sq(File.A, Rank.R8) -> Piece.BlackKing
-    ))
-    GameController.processMove(b, Color.White, "a1h8") match
+    )))
+    GameController.processMove(ctx, Color.White, "a1h8") match
       case MoveResult.Checkmate(winner) => winner shouldBe Color.White
       case other => fail(s"Expected Checkmate(White), got $other")
 
   test("processMove: legal move that results in stalemate returns Stalemate"):
     // White Qb1, Kc6; Black Ka8 — White plays Qb1-Qb6
     // After Qb6: White Qb6 + Kc6 vs Black Ka8 = stalemate (spec-verified position)
-    val b = Board(Map(
+    val ctx = GameContext(Board(Map(
       sq(File.B, Rank.R1) -> Piece.WhiteQueen,
       sq(File.C, Rank.R6) -> Piece.WhiteKing,
       sq(File.A, Rank.R8) -> Piece.BlackKing
-    ))
-    GameController.processMove(b, Color.White, "b1b6") match
+    )))
+    GameController.processMove(ctx, Color.White, "b1b6") match
       case MoveResult.Stalemate => succeed
       case other => fail(s"Expected Stalemate, got $other")
 
@@ -163,7 +165,7 @@ class GameControllerTest extends AnyFunSuite with Matchers:
     ))
     val output = captureOutput:
       withInput("a1h8\nquit\n"):
-        GameController.gameLoop(b, Color.White)
+        GameController.gameLoop(GameContext(b), Color.White)
     output should include("Checkmate! White wins.")
 
   test("gameLoop: stalemate prints draw message and resets to new game"):
@@ -174,7 +176,7 @@ class GameControllerTest extends AnyFunSuite with Matchers:
     ))
     val output = captureOutput:
       withInput("b1b6\nquit\n"):
-        GameController.gameLoop(b, Color.White)
+        GameController.gameLoop(GameContext(b), Color.White)
     output should include("Stalemate! The game is a draw.")
 
   test("gameLoop: MovedInCheck without capture prints check message"):
@@ -185,7 +187,7 @@ class GameControllerTest extends AnyFunSuite with Matchers:
     ))
     val output = captureOutput:
       withInput("a1a8\nquit\n"):
-        GameController.gameLoop(b, Color.White)
+        GameController.gameLoop(GameContext(b), Color.White)
     output should include("Black is in check!")
 
   test("gameLoop: MovedInCheck with capture prints both capture and check message"):
@@ -198,6 +200,6 @@ class GameControllerTest extends AnyFunSuite with Matchers:
     ))
     val output = captureOutput:
       withInput("a1a8\nquit\n"):
-        GameController.gameLoop(b, Color.White)
+        GameController.gameLoop(GameContext(b), Color.White)
     output should include("captures")
     output should include("Black is in check!")