✨ Dispose current session when logout

lib/providers/userinfo.dart

@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import 'package:shared_preferences/shared_preferences.dart';
@@ -35,6 +37,32 @@ class UserProvider extends ChangeNotifier {
     });
   }
 
+  Future<Map<String, dynamic>?> get atkClaims async {
+    final tk = (await atk);
+    if (tk == null) return null;
+    final atkParts = tk.split('.');
+    if (atkParts.length != 3) {
+      throw Exception('invalid format of access token');
+    }
+
+    var rawPayload = atkParts[1].replaceAll('-', '+').replaceAll('_', '/');
+    switch (rawPayload.length % 4) {
+      case 0:
+        break;
+      case 2:
+        rawPayload += '==';
+        break;
+      case 3:
+        rawPayload += '=';
+        break;
+      default:
+        throw Exception('illegal format of access token payload');
+    }
+
+    final b64 = utf8.fuse(base64Url);
+    return jsonDecode(b64.decode(rawPayload));
+  }
+
   Future<SnAccount?> refreshUser() async {
     final resp = await _sn.client.get('/cgi/id/users/me');
     final out = SnAccount.fromJson(resp.data);
@@ -47,7 +75,13 @@ class UserProvider extends ChangeNotifier {
   }
 
   void logoutUser() async {
-    _sn.clearTokenPair();
+    atkClaims.then((value) async {
+      if (value != null) {
+        await _sn.client.delete('/cgi/id/users/me/tickets/${value['sed']}');
+        logging.info('[Auth] Current session has been destroyed.');
+      }
+      _sn.clearTokenPair();
+    });
     isAuthorized = false;
     user = null;
     notifyListeners();