promotion without undo

src/backend/Board.java

@@ -13,6 +13,7 @@ public class Board {
     private Integer selectedY = null;
     private ArrayList<int[]> highlightedSquares = new ArrayList<>();
     private ArrayList<Move> moveHistory = new ArrayList<>();
+    private int[] enPassantTarget = null;
 
 
 	/*public Board(int colNum, int lineNum) {
@@ -203,8 +204,38 @@ public class Board {
 	    selectedX = null;
 	    selectedY = null;
 	    highlightedSquares.clear();
+
+        // Check for en passant capture BEFORE updating enPassantTarget!
+	    if (selectedPiece.getType() == PieceType.Pawn &&
+	    	    enPassantTarget != null &&
+	    	    x == enPassantTarget[0] &&
+	    	    y == enPassantTarget[1]) {
+
+	    	    int capturedY = selectedPiece.isWhite() ? y - 1 : y + 1;
+	    	    Piece capturedPawn = getPieceAt(x, capturedY);
+
+	    	    // Validate that it's an enemy pawn that just moved two steps
+	    	    if (capturedPawn != null &&
+	    	        capturedPawn.getType() == PieceType.Pawn &&
+	    	        capturedPawn.isWhite() != selectedPiece.isWhite()) {
+	    	        
+	    	        // Remove the pawn captured en passant
+	    	        pieces.remove(capturedPawn);
+	    	    }
+	    	}
+
+
+        // Update enPassantTarget
+        if (selectedPiece.getType() == PieceType.Pawn && selectedY != null && Math.abs(y - selectedY) == 2) {
+            int middleY = (y + selectedY) / 2;
+            enPassantTarget = new int[]{x, middleY};
+        } else {
+            enPassantTarget = null;
+        }
+		
 	}
 
+
 	public boolean isSelected(int x, int y) {
 	    return selectedX != null && selectedY != null && selectedX == x && selectedY == y;
 	}
@@ -416,19 +447,18 @@ public ArrayList<int[]> computeLegalMoves(Piece piece) {
     PieceType type = piece.getType();
 
     if (type == PieceType.Pawn) {
-        int dir = piece.isWhite() ? -1 : 1; // reverse the -1 and 1 to match the board 
+        int dir = piece.isWhite() ? -1 : 1;
         int nextY = y + dir;
-        boolean isPromoting =(piece.isWhite() && nextY == 7)||(!piece.isWhite() && nextY==0);
-        
+
         // Move forward if square is empty
         if (isEmpty(x, nextY)) {
             moves.add(new int[]{x, nextY});
-            
-            // Check for first move double step
-            int startRow = piece.isWhite()? 6:1; // same here i reversed 6 and 1
+
+            // First move double step
+            int startRow = piece.isWhite() ? 6 : 1;
             int twoStepsY = y + 2 * dir;
-            if (y== startRow && isEmpty(x,twoStepsY)) {
-            	moves.add(new int[] {x, twoStepsY});
+            if (y == startRow && isEmpty(x, twoStepsY)) {
+                moves.add(new int[]{x, twoStepsY});
             }
         }
 
@@ -439,15 +469,23 @@ public ArrayList<int[]> computeLegalMoves(Piece piece) {
         if (isEnemy(x + 1, nextY, piece.isWhite())) {
             moves.add(new int[]{x + 1, nextY});
         }
-        //promotion à revoir ca marche pas
-        if (isPromoting) {
-        	piece.setType(PieceType.Queen);
-        	piece.setY(nextY);
+
+        // En passant
+        if (enPassantTarget != null) {
+            int targetX = enPassantTarget[0];
+            int targetY = enPassantTarget[1];
+            if (nextY == targetY && Math.abs(x - targetX) == 1) {
+                moves.add(new int[]{targetX, targetY});
             }
-        // en passant
-        
         }
 
+        // Promotion check (you shouldn't promote here — only on move execution)
+        // Do NOT change piece type inside this method
+    }
+
+	
+	
+
 
     if (type == PieceType.Rook) {
         // Directions : haut, bas, gauche, droite
@@ -538,10 +576,13 @@ public ArrayList<int[]> computeLegalMoves(Piece piece) {
                 }
             }
         }
+    
     }
-     
+
+    
     return moves;
-}
+
 
 }
 
+}

src/backend/Move.java

@@ -24,4 +24,6 @@ public class Move {
     public boolean isWhite() { return isWhite; }
     public PieceType getType() { return type; }
     public Piece getCapturedPiece() { return capturedPiece; }
-}
+	}
+
+