Update methods export and cleanup pgn files

src/util/pgn_util.py

@@ -1,5 +1,9 @@
+import logging
 import chess.pgn
 import tempfile
+import os
+import time
+import glob
 
 
 # Load game
@@ -9,12 +13,31 @@ def read_pgn(pgn_filepath):
     return game
 
 
-def export_pgn(game):
-    # Create a temp file with .pgn extension that won't be auto-deleted
-    with tempfile.NamedTemporaryFile(delete=False, suffix=".pgn", mode="w") as tmp:
+def export_pgn(game, tmp_dir="tmp_pgn"):
+    os.makedirs(tmp_dir, exist_ok=True)
+
+    with tempfile.NamedTemporaryFile(
+        delete=False, suffix=".pgn", dir=tmp_dir, mode="w", encoding="utf-8"
+    ) as tmp:
         exporter = chess.pgn.FileExporter(tmp)
         game.accept(exporter)
-        return tmp.name  # Return the file path so Gradio can serve it
+        return tmp.name
+
+
+def cleanup_tmp_pgn(tmp_dir="tmp_pgn", expire_seconds=300):
+    if not os.path.exists(tmp_dir):
+        return
+
+    now = time.time()
+    pgn_files = glob.glob(os.path.join(tmp_dir, "*.pgn"))
+
+    for file_path in pgn_files:
+        try:
+            if now - os.path.getmtime(file_path) > expire_seconds:
+                os.remove(file_path)
+                logging.info(f"Deleted: {file_path}")
+        except Exception as e:
+            logging.warning(f"Error deleting {file_path}: {e}")
 
 
 def format_pv(pv_moves, board):