modules/api/src/main/scala/de/nowchess/api/game/GameHistory.scala

@@ -1,51 +0,0 @@
-package de.nowchess.api.game
-
-import de.nowchess.api.board.{PieceType, Square}
-import de.nowchess.api.move.{Move, PromotionPiece}
-
-/** A single move recorded in the game history. Distinct from api.move.Move which represents user intent. */
-case class HistoryMove(
-  from: Square,
-  to: Square,
-  castleSide: Option[String] = None,
-  promotionPiece: Option[PromotionPiece] = None,
-  pieceType: PieceType = PieceType.Pawn,
-  isCapture: Boolean = false
-)
-
-/** Complete game history: ordered list of moves plus the half-move clock for the 50-move rule.
- *
- *  @param moves         moves played so far, oldest first
- *  @param halfMoveClock plies since the last pawn move or capture (FIDE 50-move rule counter)
- *
- *  Deprecated: Use GameContext instead. This exists for compatibility during migration.
- */
-case class GameHistory(moves: List[HistoryMove] = List.empty, halfMoveClock: Int = 0):
-
-  /** Add a raw HistoryMove record. Clock increments by 1.
-   *  Use the coordinate overload when you know whether the move is a pawn move or capture.
-   */
-  def addMove(move: HistoryMove): GameHistory =
-    GameHistory(moves :+ move, halfMoveClock + 1)
-
-  /** Add a move by coordinates.
-   *
-   *  @param wasPawnMove true when the moving piece is a pawn — resets the clock to 0
-   *  @param wasCapture  true when a piece was captured (including en passant) — resets the clock to 0
-   *
-   *  If neither flag is set the clock increments by 1.
-   */
-  def addMove(
-    from: Square,
-    to: Square,
-    castleSide: Option[String] = None,
-    promotionPiece: Option[PromotionPiece] = None,
-    wasPawnMove: Boolean = false,
-    wasCapture: Boolean = false,
-    pieceType: PieceType = PieceType.Pawn
-  ): GameHistory =
-    val newClock = if wasPawnMove || wasCapture then 0 else halfMoveClock + 1
-    GameHistory(moves :+ HistoryMove(from, to, castleSide, promotionPiece, pieceType, wasCapture), newClock)
-
-object GameHistory:
-  val empty: GameHistory = GameHistory()

modules/api/src/main/scala/de/nowchess/api/game/HistoryMove.scala

@@ -0,0 +1,15 @@
+package de.nowchess.api.game
+
+import de.nowchess.api.board.{PieceType, Square}
+import de.nowchess.api.move.PromotionPiece
+
+/** A single move recorded in game history and PGN workflows. */
+case class HistoryMove(
+  from: Square,
+  to: Square,
+  castleSide: Option[String] = None,
+  promotionPiece: Option[PromotionPiece] = None,
+  pieceType: PieceType = PieceType.Pawn,
+  isCapture: Boolean = false
+)
+

modules/core/src/test/scala/de/nowchess/chess/logic/GameHistoryTest.scala

@@ -1,105 +0,0 @@
-package de.nowchess.chess.logic
-
-import de.nowchess.api.board.*
-import de.nowchess.api.move.PromotionPiece
-import de.nowchess.api.game.{GameHistory, HistoryMove}
-import org.scalatest.funsuite.AnyFunSuite
-import org.scalatest.matchers.should.Matchers
-
-class GameHistoryTest extends AnyFunSuite with Matchers:
-
-  private def sq(f: File, r: Rank): Square = Square(f, r)
-
-  test("GameHistory starts empty"):
-    val history = GameHistory.empty
-    history.moves shouldBe empty
-
-  test("GameHistory can add a move"):
-    val history = GameHistory.empty.addMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4))
-    history.moves should have length 1
-    history.moves.head.from shouldBe sq(File.E, Rank.R2)
-    history.moves.head.to shouldBe sq(File.E, Rank.R4)
-    history.moves.head.castleSide shouldBe None
-
-  test("GameHistory can add multiple moves in order"):
-    val h1 = GameHistory.empty
-    val h2 = h1.addMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4))
-    val h3 = h2.addMove(sq(File.C, Rank.R7), sq(File.C, Rank.R5))
-    h3.moves should have length 2
-    h3.moves(0).from shouldBe sq(File.E, Rank.R2)
-    h3.moves(1).from shouldBe sq(File.C, Rank.R7)
-
-  test("GameHistory can add a castle move"):
-    val history = GameHistory.empty.addMove(
-      sq(File.E, Rank.R1),
-      sq(File.G, Rank.R1),
-      Some("Kingside")
-    )
-    history.moves.head.castleSide shouldBe Some("Kingside")
-
-  test("GameHistory.addMove with two arguments uses None for castleSide default"):
-    val history = GameHistory.empty.addMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4))
-    history.moves should have length 1
-    history.moves.head.castleSide shouldBe None
-
-  test("Move with promotion records the promotion piece"):
-    val move = HistoryMove(sq(File.E, Rank.R7), sq(File.E, Rank.R8), None, Some(PromotionPiece.Queen))
-    move.promotionPiece should be (Some(PromotionPiece.Queen))
-
-  test("Normal move has no promotion piece"):
-    val move = HistoryMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4), None, None)
-    move.promotionPiece should be (None)
-
-  test("addMove with promotion stores promotionPiece"):
-    val history = GameHistory.empty
-    val newHistory = history.addMove(sq(File.E, Rank.R7), sq(File.E, Rank.R8), None, Some(PromotionPiece.Rook))
-    newHistory.moves should have length 1
-    newHistory.moves.head.promotionPiece should be (Some(PromotionPiece.Rook))
-
-  test("addMove with castleSide only uses promotionPiece default (None)"):
-    val history = GameHistory.empty
-    // With overload 3 removed, this uses the 4-param version and triggers addMove$default$4
-    val newHistory = history.addMove(sq(File.E, Rank.R1), sq(File.G, Rank.R1), Some("Kingside"))
-    newHistory.moves should have length 1
-    newHistory.moves.head.castleSide should be (Some("Kingside"))
-    newHistory.moves.head.promotionPiece should be (None)
-
-  test("addMove using named parameters with only promotion, using castleSide default"):
-    val history = GameHistory.empty
-    val newHistory = history.addMove(from = sq(File.E, Rank.R7), to = sq(File.E, Rank.R8), promotionPiece = Some(PromotionPiece.Queen))
-    newHistory.moves should have length 1
-    newHistory.moves.head.castleSide should be (None)
-    newHistory.moves.head.promotionPiece should be (Some(PromotionPiece.Queen))
-
-  // ──── half-move clock ────────────────────────────────────────────────
-
-  test("halfMoveClock starts at 0"):
-    GameHistory.empty.halfMoveClock shouldBe 0
-
-  test("halfMoveClock increments on a non-pawn non-capture move"):
-    val h = GameHistory.empty.addMove(sq(File.G, Rank.R1), sq(File.F, Rank.R3))
-    h.halfMoveClock shouldBe 1
-
-  test("halfMoveClock resets to 0 on a pawn move"):
-    val h = GameHistory.empty.addMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4), wasPawnMove = true)
-    h.halfMoveClock shouldBe 0
-
-  test("halfMoveClock resets to 0 on a capture"):
-    val h = GameHistory.empty.addMove(sq(File.E, Rank.R5), sq(File.D, Rank.R6), wasCapture = true)
-    h.halfMoveClock shouldBe 0
-
-  test("halfMoveClock resets to 0 when both wasPawnMove and wasCapture are true"):
-    val h = GameHistory.empty.addMove(sq(File.E, Rank.R5), sq(File.D, Rank.R6), wasPawnMove = true, wasCapture = true)
-    h.halfMoveClock shouldBe 0
-
-  test("halfMoveClock carries across multiple moves"):
-    val h = GameHistory.empty
-      .addMove(sq(File.G, Rank.R1), sq(File.F, Rank.R3))          // +1 → 1
-      .addMove(sq(File.G, Rank.R8), sq(File.F, Rank.R6))          // +1 → 2
-      .addMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4), wasPawnMove = true)  // reset → 0
-      .addMove(sq(File.B, Rank.R1), sq(File.C, Rank.R3))          // +1 → 1
-    h.halfMoveClock shouldBe 1
-
-  test("GameHistory can be initialised with a non-zero halfMoveClock"):
-    val h = GameHistory(halfMoveClock = 42)
-    h.halfMoveClock shouldBe 42

modules/core/src/test/scala/de/nowchess/chess/logic/HistoryMoveTest.scala

@@ -0,0 +1,48 @@
+package de.nowchess.chess.logic
+
+import de.nowchess.api.board.*
+import de.nowchess.api.move.PromotionPiece
+import de.nowchess.api.game.HistoryMove
+import org.scalatest.funsuite.AnyFunSuite
+import org.scalatest.matchers.should.Matchers
+
+class HistoryMoveTest extends AnyFunSuite with Matchers:
+
+  private def sq(f: File, r: Rank): Square = Square(f, r)
+
+  test("Move with promotion records the promotion piece"):
+    val move = HistoryMove(sq(File.E, Rank.R7), sq(File.E, Rank.R8), None, Some(PromotionPiece.Queen))
+    move.promotionPiece should be (Some(PromotionPiece.Queen))
+
+  test("Normal move has no promotion piece"):
+    val move = HistoryMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4), None, None)
+    move.promotionPiece should be (None)
+
+  test("HistoryMove default values are compatible with normal pawn move"):
+    val move = HistoryMove(sq(File.E, Rank.R2), sq(File.E, Rank.R4))
+    move.castleSide shouldBe None
+    move.promotionPiece shouldBe None
+    move.pieceType shouldBe PieceType.Pawn
+    move.isCapture shouldBe false
+
+  test("HistoryMove stores castle side and capture marker"):
+    val move = HistoryMove(
+      from = sq(File.E, Rank.R1),
+      to = sq(File.G, Rank.R1),
+      castleSide = Some("Kingside"),
+      pieceType = PieceType.King
+    )
+    move.castleSide shouldBe Some("Kingside")
+    move.pieceType shouldBe PieceType.King
+
+  test("HistoryMove stores explicit piece and capture flags"):
+    val move = HistoryMove(
+      from = sq(File.G, Rank.R1),
+      to = sq(File.F, Rank.R3),
+      pieceType = PieceType.Knight,
+      isCapture = true
+    )
+    move.pieceType shouldBe PieceType.Knight
+    move.isCapture shouldBe true
+
+

modules/io/src/main/scala/de/nowchess/io/pgn/PgnExporter.scala

@@ -2,7 +2,7 @@ package de.nowchess.io.pgn
 
 import de.nowchess.api.board.*
 import de.nowchess.api.move.{PromotionPiece, MoveType}
-import de.nowchess.api.game.{GameHistory, HistoryMove, GameContext}
+import de.nowchess.api.game.{GameContext, HistoryMove}
 import de.nowchess.io.GameContextExport
 import de.nowchess.rules.sets.DefaultRules
 
@@ -42,18 +42,17 @@ object PgnExporter extends GameContextExport:
       historyMoves += HistoryMove(move.from, move.to, castleSide, promotionPiece, pieceType, isCapture)
       ctx = DefaultRules.applyMove(ctx, move)
 
-    val history = GameHistory(historyMoves.toList, context.halfMoveClock)
-    exportGame(headers, history)
+    exportGame(headers, historyMoves.toList)
 
-  /** Export a game with headers and history to PGN format. */
-  def exportGame(headers: Map[String, String], history: GameHistory): String =
+  /** Export a game with headers and history moves to PGN format. */
+  def exportGame(headers: Map[String, String], moves: List[HistoryMove]): String =
     val headerLines = headers.map { case (key, value) =>
       s"""[$key "$value"]"""
     }.mkString("\n")
 
-    val moveText = if history.moves.isEmpty then ""
+    val moveText = if moves.isEmpty then ""
     else
-      val groupedMoves = history.moves.zipWithIndex.groupBy(_._2 / 2)
+      val groupedMoves = moves.zipWithIndex.groupBy(_._2 / 2)
       val moveLines = for (moveNumber, movePairs) <- groupedMoves.toList.sortBy(_._1) yield
         val moveNum = moveNumber + 1
         val whiteMoveStr = movePairs.find(_._2 % 2 == 0).map(p => moveToAlgebraic(p._1)).getOrElse("")

modules/io/src/test/scala/de/nowchess/io/pgn/PgnExporterTest.scala

@@ -2,8 +2,7 @@ package de.nowchess.io.pgn
 
 import de.nowchess.api.board.{PieceType, *}
 import de.nowchess.api.move.{PromotionPiece, Move, MoveType}
-import de.nowchess.api.game.{GameHistory, HistoryMove, GameContext}
-import de.nowchess.io.pgn.PgnParser
+import de.nowchess.api.game.{GameContext, HistoryMove}
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 
@@ -11,8 +10,7 @@ class PgnExporterTest extends AnyFunSuite with Matchers:
 
   test("export empty game") {
     val headers = Map("Event" -> "Test", "White" -> "A", "Black" -> "B")
-    val history = GameHistory.empty
-    val pgn = PgnExporter.exportGame(headers, history)
+    val pgn = PgnExporter.exportGame(headers, List.empty)
 
     pgn.contains("[Event \"Test\"]") shouldBe true
     pgn.contains("[White \"A\"]") shouldBe true
@@ -21,97 +19,87 @@ class PgnExporterTest extends AnyFunSuite with Matchers:
 
   test("export single move") {
     val headers = Map("Event" -> "Test", "White" -> "A", "Black" -> "B")
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
-    val pgn = PgnExporter.exportGame(headers, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
+    val pgn = PgnExporter.exportGame(headers, moves)
 
     pgn.contains("1. e4") shouldBe true
   }
 
   test("export castling") {
     val headers = Map("Event" -> "Test")
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R1), Square(File.G, Rank.R1), Some("Kingside")))
-    val pgn = PgnExporter.exportGame(headers, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R1), Square(File.G, Rank.R1), Some("Kingside")))
+    val pgn = PgnExporter.exportGame(headers, moves)
 
     pgn.contains("O-O") shouldBe true
   }
 
   test("export game sequence") {
     val headers = Map("Event" -> "Test", "White" -> "A", "Black" -> "B", "Result" -> "1-0")
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
-      .addMove(HistoryMove(Square(File.C, Rank.R7), Square(File.C, Rank.R5), None))
-      .addMove(HistoryMove(Square(File.G, Rank.R1), Square(File.F, Rank.R3), None, pieceType = PieceType.Knight))
-    val pgn = PgnExporter.exportGame(headers, history)
+    val moves = List(
+      HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None),
+      HistoryMove(Square(File.C, Rank.R7), Square(File.C, Rank.R5), None),
+      HistoryMove(Square(File.G, Rank.R1), Square(File.F, Rank.R3), None, pieceType = PieceType.Knight)
+    )
+    val pgn = PgnExporter.exportGame(headers, moves)
 
     pgn.contains("1. e4 c5") shouldBe true
     pgn.contains("2. Nf3") shouldBe true
   }
 
   test("export game with no headers returns only move text") {
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
-    val pgn = PgnExporter.exportGame(Map.empty, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
+    val pgn = PgnExporter.exportGame(Map.empty, moves)
 
     pgn shouldBe "1. e4 *"
   }
 
   test("export queenside castling") {
     val headers = Map("Event" -> "Test")
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R1), Square(File.C, Rank.R1), Some("Queenside")))
-    val pgn = PgnExporter.exportGame(headers, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R1), Square(File.C, Rank.R1), Some("Queenside")))
+    val pgn = PgnExporter.exportGame(headers, moves)
 
     pgn.contains("O-O-O") shouldBe true
   }
 
   test("exportGame encodes promotion to Queen as =Q suffix") {
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R7), Square(File.E, Rank.R8), None, Some(PromotionPiece.Queen)))
-    val pgn = PgnExporter.exportGame(Map.empty, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R7), Square(File.E, Rank.R8), None, Some(PromotionPiece.Queen)))
+    val pgn = PgnExporter.exportGame(Map.empty, moves)
     pgn should include ("e8=Q")
   }
 
   test("exportGame encodes promotion to Rook as =R suffix") {
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R7), Square(File.E, Rank.R8), None, Some(PromotionPiece.Rook)))
-    val pgn = PgnExporter.exportGame(Map.empty, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R7), Square(File.E, Rank.R8), None, Some(PromotionPiece.Rook)))
+    val pgn = PgnExporter.exportGame(Map.empty, moves)
     pgn should include ("e8=R")
   }
 
   test("exportGame encodes promotion to Bishop as =B suffix") {
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R7), Square(File.E, Rank.R8), None, Some(PromotionPiece.Bishop)))
-    val pgn = PgnExporter.exportGame(Map.empty, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R7), Square(File.E, Rank.R8), None, Some(PromotionPiece.Bishop)))
+    val pgn = PgnExporter.exportGame(Map.empty, moves)
     pgn should include ("e8=B")
   }
 
   test("exportGame encodes promotion to Knight as =N suffix") {
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R7), Square(File.E, Rank.R8), None, Some(PromotionPiece.Knight)))
-    val pgn = PgnExporter.exportGame(Map.empty, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R7), Square(File.E, Rank.R8), None, Some(PromotionPiece.Knight)))
+    val pgn = PgnExporter.exportGame(Map.empty, moves)
     pgn should include ("e8=N")
   }
 
   test("exportGame does not add suffix for normal moves") {
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None, None))
-    val pgn = PgnExporter.exportGame(Map.empty, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None, None))
+    val pgn = PgnExporter.exportGame(Map.empty, moves)
     pgn should include ("e4")
-    pgn should not include ("=")
+    pgn should not include "="
   }
 
   test("exportGame uses Result header as termination marker"):
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
-    val pgn = PgnExporter.exportGame(Map("Result" -> "1/2-1/2"), history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
+    val pgn = PgnExporter.exportGame(Map("Result" -> "1/2-1/2"), moves)
     pgn should endWith("1/2-1/2")
 
   test("exportGame with no Result header still uses * as default"):
-    val history = GameHistory()
-      .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
-    val pgn = PgnExporter.exportGame(Map.empty, history)
+    val moves = List(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
+    val pgn = PgnExporter.exportGame(Map.empty, moves)
     pgn shouldBe "1. e4 *"
 
   test("exportGameContext: moves are preserved in output") {

modules/io/src/test/scala/de/nowchess/io/pgn/PgnValidatorTest.scala

@@ -2,7 +2,6 @@ package de.nowchess.io.pgn
 
 import de.nowchess.api.board.*
 import de.nowchess.api.move.PromotionPiece
-import de.nowchess.api.game.{GameHistory, HistoryMove}
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers
 

modules/ui/src/main/scala/de/nowchess/ui/gui/ChessBoardView.scala

@@ -11,7 +11,6 @@ import scalafx.scene.shape.Rectangle
 import scalafx.scene.text.{Font, Text}
 import scalafx.stage.Stage
 import de.nowchess.api.board.{Board, Color, File, Piece, PieceType, Rank, Square}
-import de.nowchess.api.game.{GameHistory, HistoryMove}
 import de.nowchess.api.move.PromotionPiece
 import de.nowchess.chess.command.{MoveCommand, MoveResult}
 import de.nowchess.chess.engine.GameEngine
@@ -178,7 +177,7 @@ class ChessBoardView(val stage: Stage, private val engine: GameEngine) extends B
           if piece.color == currentTurn then
             selectedSquare = Some(clickedSquare)
             highlightSquare(rank, file, PieceSprites.SquareColors.Selected)
-            
+
             val legalDests = engine.ruleSet.legalMoves(engine.context, clickedSquare)
                .collect { case move if move.from == clickedSquare => move.to }
             legalDests.foreach { sq =>
@@ -289,7 +288,7 @@ class ChessBoardView(val stage: Stage, private val engine: GameEngine) extends B
 
   private def doPgnImport(): Unit =
     doImport(PgnParser, "PGN")
-    
+
   private def doExport(exporter: GameContextExport, formatName: String): Unit = {
     val exported = exporter.exportGameContext(engine.context)
     showCopyDialog(s"$formatName Export", exported)

modules/ui/src/main/scala/de/nowchess/ui/terminal/TerminalUI.scala

@@ -3,8 +3,8 @@ package de.nowchess.ui.terminal
 import scala.io.StdIn
 import de.nowchess.api.move.PromotionPiece
 import de.nowchess.chess.engine.GameEngine
-import de.nowchess.chess.observer.{Observer, GameEvent, *}
-import de.nowchess.chess.view.Renderer
+import de.nowchess.chess.observer.*
+import de.nowchess.ui.utils.Renderer
 
 /** Terminal UI that implements Observer pattern.
  *  Subscribes to GameEngine and receives state change events.

modules/ui/src/main/scala/de/nowchess/ui/utils/PieceUnicode.scala

@@ -1,4 +1,4 @@
-package de.nowchess.chess.view
+package de.nowchess.ui.utils
 
 import de.nowchess.api.board.{Color, Piece, PieceType}
 

modules/ui/src/main/scala/de/nowchess/ui/utils/Renderer.scala

@@ -1,6 +1,6 @@
-package de.nowchess.chess.view
+package de.nowchess.ui.utils
 
-import de.nowchess.api.board.{Board, Color, File, Rank, Square}
+import de.nowchess.api.board.*
 
 object Renderer:
 

modules/ui/src/test/scala/de/nowchess/ui/utils/PieceUnicodeTest.scala

@@ -1,4 +1,4 @@
-package de.nowchess.chess.view
+package de.nowchess.ui.utils
 
 import de.nowchess.api.board.Piece
 import org.scalatest.funsuite.AnyFunSuite

modules/ui/src/test/scala/de/nowchess/ui/utils/RendererTest.scala

@@ -1,6 +1,6 @@
-package de.nowchess.chess.view
+package de.nowchess.ui.utils
 
-import de.nowchess.api.board.{Board, File, Piece, Rank, Square}
+import de.nowchess.api.board.*
 import org.scalatest.funsuite.AnyFunSuite
 import org.scalatest.matchers.should.Matchers