win and lose

src/backend/Board.java

@@ -631,5 +631,40 @@ public void playMove(Move move) {
 	    }
 	    return score;
 	}
+	public enum GameResult {
+        ONGOING,    // game still in progress
+        DRAW,       // stalemate (or other draw condition)
+        WHITE_WINS, // black is checkmated
+        BLACK_WINS  // white is checkmated
+    }
+
+    /**
+     * @return the current game result: ONGOING, DRAW, WHITE_WINS or BLACK_WINS.
+     */
+    public GameResult getGameResult() {
+        // if White is checkmated → Black wins
+        if (isCheckmate(true))  return GameResult.BLACK_WINS;
+        // if Black is checkmated → White wins
+        if (isCheckmate(false)) return GameResult.WHITE_WINS;
+        // if side to move has no legal moves but is not in check → stalemate
+        if (isStalemate(true) || isStalemate(false)) return GameResult.DRAW;
+        return GameResult.ONGOING;
+    }
+
+    /**
+     * @param whitePlayer whose turn we're checking for stalemate
+     * @return true if whitePlayer is not in check and has no legal moves
+     */
+    private boolean isStalemate(boolean whitePlayer) {
+        // must not be in check
+        if (isInCheck(whitePlayer)) return false;
+        // and have no legal moves
+        for (Piece p : pieces) {
+            if (p.isWhite() == whitePlayer && !getLegalMoves(p).isEmpty()) {
+                return false;
+            }
+        }
+        return true;
+    }
+}
 
-}  

src/backend/Game.java

@@ -1,6 +1,8 @@
 package backend;
 
 import windowInterface.MyInterface;
+import backend.Board.GameResult;
+
 import java.nio.file.Path;
 import java.nio.file.Files;
 import java.nio.charset.StandardCharsets;
@@ -16,6 +18,7 @@ public class Game extends Thread {
     private int LINE_NUM = 8;
     private int loopDelay = 250;
     private boolean[] activationAIFlags;
+    private boolean gameOver = false;  // ← track when the game ends
 
     public Game(MyInterface mjfParam) {
         mjf = mjfParam;
@@ -35,17 +38,19 @@ public class Game extends Thread {
         board = new Board(lines.toArray(new String[0]));
         // refresh UI for the new board state:
         mjf.update(board.getTurnNumber(), board.isTurnWhite());
+        checkGameOver();
     }
     // ───────────────────────────────────────────────────────────────────────
 
-    public int getWidth()        { return board.getWidth(); }
-    public int getHeight()       { return board.getHeight(); }
+    public int getWidth()  { return board.getWidth();  }
+    public int getHeight() { return board.getHeight(); }
 
     @Override
     public void run() {
-        while(true) {
+        while (!gameOver) {
             aiPlayerTurn();
             mjf.update(board.getTurnNumber(), board.isTurnWhite());
+            checkGameOver();
             try { Thread.sleep(loopDelay); }
             catch (InterruptedException e) { e.printStackTrace(); }
         }
@@ -58,7 +63,9 @@ public class Game extends Thread {
     private void aiPlayerTurn() {
         if (isAITurn()) {
             Move bestMove = aiPlayer.getBestMoveUsingNegamax(board, 2);
-            if (bestMove != null) board.playMove(bestMove);
+            if (bestMove != null) {
+                board.playMove(bestMove);
+            }
         }
     }
 
@@ -67,7 +74,11 @@ public class Game extends Thread {
             System.out.println("Click out of bounds");
             return;
         }
-        if (!isAITurn()) board.userTouch(x, y);
+        if (!isAITurn()) {
+            board.userTouch(x, y);
+            mjf.update(board.getTurnNumber(), board.isTurnWhite());
+            checkGameOver();
+        }
     }
 
     public void setPiece(boolean isWhite, PieceType type, int x, int y) {
@@ -89,6 +100,8 @@ public class Game extends Thread {
 
     public void setBoard(String[] array) {
         board = new Board(array);
+        mjf.update(board.getTurnNumber(), board.isTurnWhite());
+        checkGameOver();
     }
 
     public Iterable<Piece> getPieces() {
@@ -105,9 +118,28 @@ public class Game extends Thread {
 
     public void undoLastMove() {
         board.undoLastMove();
+        mjf.update(board.getTurnNumber(), board.isTurnWhite());
+        gameOver = false;  // allow play to continue after undo
     }
 
     public void toggleAI(boolean isWhite) {
         activationAIFlags[isWhite ? 1 : 0] = !activationAIFlags[isWhite ? 1 : 0];
     }
+
+    // ─── WIN/LOSE/DRAW logic ───────────────────────────────────────────────
+    private void checkGameOver() {
+        GameResult res = board.getGameResult();
+        if (res != GameResult.ONGOING) {
+            String msg;
+            switch (res) {
+                case WHITE_WINS: msg = "White wins!"; break;
+                case BLACK_WINS: msg = "Black wins!"; break;
+                case DRAW:       msg = "Draw!";        break;
+                default:         msg = "";              break;
+            }
+            mjf.setStepBanner(msg);
+            gameOver = true;
+        }
+    }
+    // ───────────────────────────────────────────────────────────────────────
 }