update app.py

app.py

@@ -95,12 +95,31 @@ def get_move(board_text, player=None):
     elif player == "2":
         game.move_count = 1
     else:
-        # infer from the last part of FEN if you want, or keep fixed
-        game.move_count = 0 if player is None or "w" in board_text else 1
+        # 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)
-    best_move = max(visits, key=visits.get)
+
+    # Debug: show how many legal moves and visits
+    legal_moves = list(game.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] visits count: {len(visits)}")
+    if visits:
+        print(f"[DEBUG] sample visit key: {next(iter(visits))}")
+
+    # Safely pick a move
+    if visits:
+        best_move = max(visits, key=visits.get)
+    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}")
+
     move = move_to_uci(best_move)
     print(f"[DEBUG] get_move OK: FEN={board_text} -> {move}")
     return move