Fix token expiration issue - auto refresh token before expiry

office365_self_service/graph.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import logging
+import time
 from typing import Any
 
 import requests
@@ -16,11 +17,13 @@ class TokenManager:
         self.token_endpoint = token_endpoint
         self.scope = scope
         self._token: str | None = None
+        self._token_expires_at: float = 0
 
     def get_token(self) -> str:
-        if self._token:
+        if self._token and time.time() < self._token_expires_at - 60:
             return self._token
 
+        self.clear_token()
         data = {
             "grant_type": "client_credentials",
             "client_id": self.client_id,
@@ -29,11 +32,16 @@ class TokenManager:
         }
         response = requests.post(self.token_endpoint, data=data, timeout=30)
         response.raise_for_status()
-        self._token = response.json()["access_token"]
+        token_data = response.json()
+        self._token = token_data["access_token"]
+        expires_in = token_data.get("expires_in", 3600)
+        self._token_expires_at = time.time() + expires_in
+        logger.info(f"Token refreshed, expires in {expires_in} seconds")
         return self._token
 
     def clear_token(self) -> None:
         self._token = None
+        self._token_expires_at = 0
 
 
 class GraphAPIError(Exception):