update app.py

app.py

@@ -90,35 +90,46 @@ def get_move(board_text, player=None):
     print(f"[DEBUG] get_move FEN board_text={repr(board_text)}, player={player}")
     game = Breakthrough()
     game.board = fen_to_board(board_text)
+
     if player == "1":
         game.move_count = 0
     elif player == "2":
         game.move_count = 1
     else:
-        # Default: infer from FEN suffix or assume white
         game.move_count = 0 if " w" in board_text.lower() else 1
+
     game._cached_matrix = None
     searcher = MCVSSearcher(None, None, zonedb, lambda_zone=1.0, k_zone=5)
     visits, _ = searcher.search_with_time_budget(game, 1.0)
 
-    # Debug: show how many legal moves and visits
     legal_moves = list(game.get_legal_moves())
     print(f"[DEBUG] legal moves count: {len(legal_moves)}")
     if legal_moves:
-        print(f"[DEBUG] sample legal move: {legal_moves[0] if len(legal_moves) > 0 else None}")
+        print(f"[DEBUG] sample legal move: {legal_moves[0]}")
     print(f"[DEBUG] visits count: {len(visits)}")
     if visits:
         print(f"[DEBUG] sample visit key: {next(iter(visits))}")
 
-    # Safely pick a move
+    # Safely pick a move that is actually legal
     if visits:
-        best_move = max(visits, key=visits.get)
+        candidates = [(move, visits[move]) for move in visits if move in set(legal_moves)]
+        if candidates:
+            best_move, _ = max(candidates, key=lambda x: x[1])
+        else:
+            # Fallback to first legal move if no visited move is legal
+            if not legal_moves:
+                print("[WARNING] No legal moves; returning dummy move d4d4.")
+                best_move = (3, 3, 3, 3)  # d4 -> d4
+            else:
+                best_move = legal_moves[0]
+                print(f"[WARNING] no visited move is legal; using fallback move: {best_move}")
     else:
         if not legal_moves:
-            raise ValueError("get_move: No legal moves in position.")
-        # Fallback: use first legal move
-        best_move = legal_moves[0]
-        print(f"[WARNING] visits empty; using fallback move: {best_move}")
+            print("[WARNING] No legal moves; returning dummy move d4d4.")
+            best_move = (3, 3, 3, 3)
+        else:
+            best_move = legal_moves[0]
+            print(f"[WARNING] visits empty; using fallback move: {best_move}")
 
     move = move_to_uci(best_move)
     print(f"[DEBUG] get_move OK: FEN={board_text} -> {move}")