feat: enhance move history with piece type and capture status

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

@@ -92,9 +92,10 @@ object GameController:
           val capturedSq = EnPassantCalculator.capturedPawnSquare(to, turn)
           (b.removed(capturedSq), board.pieceAt(capturedSq))
         else (b, cap)
-    val wasPawnMove = board.pieceAt(from).exists(_.pieceType == PieceType.Pawn)
+    val pieceType   = board.pieceAt(from).map(_.pieceType).getOrElse(PieceType.Pawn)
+    val wasPawnMove = pieceType == PieceType.Pawn
     val wasCapture  = captured.isDefined
-    val newHistory  = history.addMove(from, to, castleOpt, wasPawnMove = wasPawnMove, wasCapture = wasCapture)
+    val newHistory  = history.addMove(from, to, castleOpt, wasPawnMove = wasPawnMove, wasCapture = wasCapture, pieceType = pieceType)
     toMoveResult(newBoard, newHistory, captured, turn)
 
   private def toMoveResult(newBoard: Board, newHistory: GameHistory, captured: Option[Piece], turn: Color): MoveResult =

modules/core/src/main/scala/de/nowchess/chess/logic/GameHistory.scala

@@ -1,6 +1,6 @@
 package de.nowchess.chess.logic
 
-import de.nowchess.api.board.Square
+import de.nowchess.api.board.{PieceType, Square}
 import de.nowchess.api.move.PromotionPiece
 
 /** A single move recorded in the game history. Distinct from api.move.Move which represents user intent. */
@@ -8,7 +8,9 @@ case class HistoryMove(
   from: Square,
   to: Square,
   castleSide: Option[CastleSide],
-  promotionPiece: Option[PromotionPiece] = 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.
@@ -37,10 +39,11 @@ case class GameHistory(moves: List[HistoryMove] = List.empty, halfMoveClock: Int
     castleSide: Option[CastleSide] = None,
     promotionPiece: Option[PromotionPiece] = None,
     wasPawnMove: Boolean = false,
-    wasCapture: 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), newClock)
+    GameHistory(moves :+ HistoryMove(from, to, castleSide, promotionPiece, pieceType, wasCapture), newClock)
 
 object GameHistory:
   val empty: GameHistory = GameHistory()

modules/core/src/main/scala/de/nowchess/chess/notation/PgnExporter.scala

@@ -1,6 +1,6 @@
 package de.nowchess.chess.notation
 
-import de.nowchess.api.board.*
+import de.nowchess.api.board.{PieceType, *}
 import de.nowchess.api.move.PromotionPiece
 import de.nowchess.chess.logic.{CastleSide, GameHistory, HistoryMove}
 
@@ -29,16 +29,26 @@ object PgnExporter:
     else if moveText.isEmpty then headerLines
     else s"$headerLines\n\n$moveText"
 
-  /** Convert a HistoryMove to algebraic notation. */
+  /** Convert a HistoryMove to Standard Algebraic Notation. */
   private def moveToAlgebraic(move: HistoryMove): String =
     move.castleSide match
       case Some(CastleSide.Kingside)  => "O-O"
       case Some(CastleSide.Queenside) => "O-O-O"
       case None =>
-        val base = s"${move.from}${move.to}"
+        val dest       = move.to.toString
-        move.promotionPiece match
+        val capStr     = if move.isCapture then "x" else ""
-          case Some(PromotionPiece.Queen)  => s"$base=Q"
+        val promSuffix = move.promotionPiece match
-          case Some(PromotionPiece.Rook)   => s"$base=R"
+          case Some(PromotionPiece.Queen)  => "=Q"
-          case Some(PromotionPiece.Bishop) => s"$base=B"
+          case Some(PromotionPiece.Rook)   => "=R"
-          case Some(PromotionPiece.Knight) => s"$base=N"
+          case Some(PromotionPiece.Bishop) => "=B"
-          case None                        => base
+          case Some(PromotionPiece.Knight) => "=N"
+          case None                        => ""
+        move.pieceType match
+          case PieceType.Pawn =>
+            if move.isCapture then s"${move.from.file.toString.toLowerCase}x$dest$promSuffix"
+            else s"$dest$promSuffix"
+          case PieceType.Knight => s"N$capStr$dest$promSuffix"
+          case PieceType.Bishop => s"B$capStr$dest$promSuffix"
+          case PieceType.Rook   => s"R$capStr$dest$promSuffix"
+          case PieceType.Queen  => s"Q$capStr$dest$promSuffix"
+          case PieceType.King   => s"K$capStr$dest$promSuffix"

modules/core/src/main/scala/de/nowchess/chess/notation/PgnParser.scala

@@ -79,11 +79,11 @@ object PgnParser:
     notation match
       case "O-O" | "O-O+" | "O-O#" =>
         val rank = if color == Color.White then Rank.R1 else Rank.R8
-        Some(HistoryMove(Square(File.E, rank), Square(File.G, rank), Some(CastleSide.Kingside)))
+        Some(HistoryMove(Square(File.E, rank), Square(File.G, rank), Some(CastleSide.Kingside), pieceType = PieceType.King))
 
       case "O-O-O" | "O-O-O+" | "O-O-O#" =>
         val rank = if color == Color.White then Rank.R1 else Rank.R8
-        Some(HistoryMove(Square(File.E, rank), Square(File.C, rank), Some(CastleSide.Queenside)))
+        Some(HistoryMove(Square(File.E, rank), Square(File.C, rank), Some(CastleSide.Queenside), pieceType = PieceType.King))
 
       case _ =>
         parseRegularMove(notation, board, history, color)
@@ -143,8 +143,10 @@ object PgnParser:
           if hint.isEmpty then byPiece
           else byPiece.filter(from => matchesHint(from, hint))
 
-        val promotion = extractPromotion(notation)
+        val promotion     = extractPromotion(notation)
-        disambiguated.headOption.map(from => HistoryMove(from, toSquare, None, promotion))
+        val movePieceType = requiredPieceType.getOrElse(PieceType.Pawn)
+        val moveIsCapture = notation.contains('x')
+        disambiguated.headOption.map(from => HistoryMove(from, toSquare, None, promotion, movePieceType, moveIsCapture))
 
   /** True if `sq` matches a disambiguation hint (file letter, rank digit, or both). */
   private def matchesHint(sq: Square, hint: String): Boolean =

modules/core/src/test/scala/de/nowchess/chess/notation/PgnExporterTest.scala

@@ -1,6 +1,6 @@
 package de.nowchess.chess.notation
 
-import de.nowchess.api.board.*
+import de.nowchess.api.board.{PieceType, *}
 import de.nowchess.api.move.PromotionPiece
 import de.nowchess.chess.logic.{GameHistory, HistoryMove, CastleSide}
 import org.scalatest.funsuite.AnyFunSuite
@@ -24,7 +24,7 @@ class PgnExporterTest extends AnyFunSuite with Matchers:
       .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
     val pgn = PgnExporter.exportGame(headers, history)
 
-    pgn.contains("1. e2e4") shouldBe true
+    pgn.contains("1. e4") shouldBe true
   }
 
   test("export castling") {
@@ -41,11 +41,11 @@ class PgnExporterTest extends AnyFunSuite with Matchers:
     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))
+      .addMove(HistoryMove(Square(File.G, Rank.R1), Square(File.F, Rank.R3), None, pieceType = PieceType.Knight))
     val pgn = PgnExporter.exportGame(headers, history)
 
-    pgn.contains("1. e2e4 c7c5") shouldBe true
+    pgn.contains("1. e4 c5") shouldBe true
-    pgn.contains("2. g1f3") shouldBe true
+    pgn.contains("2. Nf3") shouldBe true
   }
 
   test("export game with no headers returns only move text") {
@@ -53,7 +53,7 @@ class PgnExporterTest extends AnyFunSuite with Matchers:
       .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
     val pgn = PgnExporter.exportGame(Map.empty, history)
 
-    pgn shouldBe "1. e2e4 *"
+    pgn shouldBe "1. e4 *"
   }
 
   test("export queenside castling") {
@@ -69,35 +69,35 @@ class PgnExporterTest extends AnyFunSuite with Matchers:
     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)
-    pgn should include ("e7e8=Q")
+    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)
-    pgn should include ("e7e8=R")
+    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)
-    pgn should include ("e7e8=B")
+    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)
-    pgn should include ("e7e8=N")
+    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)
-    pgn should include ("e2e4")
+    pgn should include ("e4")
     pgn should not include ("=")
   }
 
@@ -111,4 +111,4 @@ class PgnExporterTest extends AnyFunSuite with Matchers:
     val history = GameHistory()
       .addMove(HistoryMove(Square(File.E, Rank.R2), Square(File.E, Rank.R4), None))
     val pgn = PgnExporter.exportGame(Map.empty, history)
-    pgn shouldBe "1. e2e4 *"
+    pgn shouldBe "1. e4 *"

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

@@ -43,6 +43,12 @@ class GUIObserver(private val boardView: ChessBoardView) extends Observer:
 
         case e: PromotionRequiredEvent =>
           boardView.showPromotionDialog(e.from, e.to)
+
+        case e: DrawClaimedEvent =>
+          boardView.updateBoard(e.board, e.turn)
+          showAlert(AlertType.Information, "Draw Claimed", "Draw claimed! The game is a draw.")
+        case e: FiftyMoveRuleAvailableEvent => 
+          boardView.showMessage("50-move rule available! The game is a draw.")
     }
 
   private def showAlert(alertType: AlertType, titleText: String, content: String): Unit =

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

@@ -49,6 +49,12 @@ class TerminalUI(engine: GameEngine) extends Observer:
       case _: PromotionRequiredEvent =>
         println("Promote to: q=Queen, r=Rook, b=Bishop, n=Knight")
         synchronized { awaitingPromotion = true }
+      case _: DrawClaimedEvent =>
+        println("Draw claimed! The game is a draw.")
+        println()
+        print(Renderer.render(engine.board))
+      case _: FiftyMoveRuleAvailableEvent =>
+        println("50-move rule available! The game is a draw.")
 
   /** Start the terminal UI game loop. */
   def start(): Unit =