From e71e4d633a521fb4e00e1866d32e1f496ad6b7a6 Mon Sep 17 00:00:00 2001
From: Vaibhav Surve <vaibhav.surve@marcoaiot.com>
Date: Mon, 23 Jun 2025 17:35:50 +0530
Subject: [PATCH] feat: Implement JWT token expiration handling and refresh
 logic in ApiService

---
 lib/helpers/services/api_service.dart | 46 ++++++++++++++++++++++++---
 pubspec.yaml                          |  1 +
 2 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/lib/helpers/services/api_service.dart b/lib/helpers/services/api_service.dart
index bf3903e..27be07c 100644
--- a/lib/helpers/services/api_service.dart
+++ b/lib/helpers/services/api_service.dart
@@ -7,7 +7,7 @@ import 'package:logger/logger.dart';
 import 'package:marco/helpers/services/auth_service.dart';
 import 'package:marco/helpers/services/api_endpoints.dart';
 import 'package:marco/helpers/services/storage/local_storage.dart';
-
+import 'package:jwt_decoder/jwt_decoder.dart';
 final Logger logger = Logger();
 
 class ApiService {
@@ -17,12 +17,48 @@ class ApiService {
 
   // === Helpers ===
 
-  static Future<String?> _getToken() async {
-    final token = await LocalStorage.getJwtToken();
-    if (token == null && enableLogs) logger.w("No JWT token found.");
-    return token;
+ static Future<String?> _getToken() async {
+  final token = await LocalStorage.getJwtToken();
+
+  if (token == null) {
+    if (enableLogs) logger.w("No JWT token found.");
+    return null;
   }
 
+  try {
+    // Check if the token is expired
+    if (JwtDecoder.isExpired(token)) {
+      _log("Access token is expired. Attempting refresh...");
+      final refreshed = await AuthService.refreshToken();
+      if (refreshed) {
+        return await LocalStorage.getJwtToken();
+      } else {
+        _log("Token refresh failed. Logging out...");
+        await LocalStorage.logout();
+        return null;
+      }
+    }
+
+    // Check if token is about to expire in < 2 minutes
+    final expirationDate = JwtDecoder.getExpirationDate(token);
+    final now = DateTime.now();
+    final difference = expirationDate.difference(now);
+
+    if (difference.inMinutes < 2) {
+      _log("Access token is about to expire in ${difference.inSeconds}s. Refreshing...");
+      final refreshed = await AuthService.refreshToken();
+      if (refreshed) {
+        return await LocalStorage.getJwtToken();
+      }
+    }
+
+  } catch (e) {
+    _log("Token decoding error: $e");
+  }
+
+  return token;
+}
+
   static Map<String, String> _headers(String token) => {
         'Content-Type': 'application/json',
         'Authorization': 'Bearer $token',
diff --git a/pubspec.yaml b/pubspec.yaml
index 808debf..371d19d 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -70,6 +70,7 @@ dependencies:
   percent_indicator: ^4.2.2
   flutter_contacts: ^1.1.9+2
   photo_view: ^0.15.0
+  jwt_decoder: ^2.0.1
 dev_dependencies:
   flutter_test:
     sdk: flutter