checkpoint

lib/services/auth_service.dart

@@ -170,6 +170,46 @@ class AuthService {
     }
   }
 
+  /// Check if token expires within the specified duration (default: 5 minutes)
+  bool isTokenExpiringSoon(String? token, {Duration threshold = const Duration(minutes: 5)}) {
+    if (token == null || token.isEmpty) return true;
+    try {
+      final decodedToken = JwtDecoder.decode(token);
+      final exp = decodedToken['exp'] as int?;
+      if (exp == null) return true;
+
+      final expirationTime = DateTime.fromMillisecondsSinceEpoch(exp * 1000);
+      final now = DateTime.now();
+      final timeUntilExpiration = expirationTime.difference(now);
+
+      return timeUntilExpiration <= threshold;
+    } catch (e) {
+      return true;
+    }
+  }
+
+  /// Proactively refresh token if it's expiring soon
+  /// Returns the current valid token or a newly refreshed token
+  Future<String?> ensureValidToken() async {
+    final currentToken = await getToken();
+
+    // If no token, return null
+    if (currentToken == null) return null;
+
+    // If token is still valid and not expiring soon, return it
+    if (!isTokenExpiringSoon(currentToken)) {
+      return currentToken;
+    }
+
+    // Token is expiring soon, refresh it
+    final refreshResult = await refreshAccessToken();
+    return refreshResult.when(
+      success: (newToken) => newToken,
+      onError: (error) => null,
+      cancelled: () => null,
+    );
+  }
+
   UserProfile? decodeToken(String token) {
     try {
       final decodedToken = JwtDecoder.decode(token);