Update app.py (#11)

- Update app.py (d80627198525c13b25c2760ceeab4fdcae6206d2)

app.py

@@ -238,10 +238,11 @@ class BasicAgent:
         m = FEN_RX.search(text)
         if m:
             return " ".join(m.group(1).split())  # normalize whitespace
+
         # fallback: sometimes file is just the fen line
-        t = text.strip()
+        t = " ".join(text.strip().split())
         if "/" in t and " w " in t or " b " in t:
-            return " ".join(t.split())
+            return t
         return None
 
     def _solve_chess_mate_in_one(self, fen: str) -> str | None:
@@ -263,6 +264,21 @@ class BasicAgent:
                 return san  # e.g., "Qg2#"
         return None
 
+    def _mate_in_one_san(self, fen: str) -> str | None:
+        try:
+            board = chess.Board(fen)
+        except Exception:
+            return None
+        # enumerate legal moves; if any leads to mate, return SAN
+        for mv in list(board.legal_moves):
+            board.push(mv)
+            is_mate = board.is_checkmate()
+            san = board.san(mv)
+            board.pop()
+            if is_mate:
+                return san  # e.g., "Qg2#"
+        return None
+
     # change the template call to pass task_id as second arg
     def __call__(self, question: str, task_id: str | None = None) -> str:
         ql = question.lower()
@@ -274,11 +290,11 @@ class BasicAgent:
 
 
         # CHESS fast-path
-        if ("chess" in ql or "algebraic notation" in ql or "diagram" in ql or "board" in ql) and task_id:
+        if ("chess" in ql or "algebraic notation" in ql or "board" in ql) and task_id:
             file_text = self._fetch_file_text(task_id)
-            fen = self._extract_fen(file_text or "")
+            fen = self._extract_fen(file_text)
             if fen:
-                san = self._solve_chess_mate_in_one(fen)
+                san = self._mate_in_one_san(fen)
                 if san:
                     return san