add code to convert datetime into localtime into file list and add access quarys

my_modules/file_helper_functions.py

@@ -1,7 +1,7 @@
 from my_modules.app.constens import SECRET_KEY
 
 import hmac, hashlib, base64, secrets, time
-from urllib.parse import quote, unquote
+from datetime import datetime, timezone
 
 def base64url_encode(data: bytes) -> str:
   return base64.urlsafe_b64encode(data).decode().rstrip("=")
@@ -27,6 +27,15 @@ def verify_signed_url(file_id: str, token: str, file_expiration: int) -> bool:
   not_expired = file_expiration >= time.time()
   return valid_sig and not_expired
 
+def is_expired(expires_at):
+  if not expires_at:
+    return False
+  if expires_at.tzinfo is None:
+    expires_at = expires_at.replace(tzinfo=timezone.utc)
+  else:
+    expires_at = expires_at.astimezone(timezone.utc)
+  return expires_at <= datetime.now(timezone.utc)
+
 if __name__ == "__main__":
   file_id = generate_short_id()
   url = generate_signed_url(file_id)