added guardian letters with chat and multiple answer functionalities

lib/push/push_tap_router.dart

@@ -1,24 +1,22 @@
 import 'dart:convert';
+import 'dart:developer';
 
 import 'package:flutter/foundation.dart';
 import 'package:flutter_local_notifications/flutter_local_notifications.dart';
 
 import 'push_actions.dart';
+import 'push_target.dart';
 
 /// Routes foreground notification interactions from the single
 /// flutter_local_notifications response callback. Action responses (reply /
 /// mark-read) are dispatched straight to [PushActions]; a plain tap publishes
-/// the target chat token via [pendingChatToken] for [App] to navigate to.
+/// its target via [pendingTarget] for [App] to navigate to.
 class PushTapRouter {
   PushTapRouter._();
 
-  /// Chat token of the most recently tapped Talk notification, or null. [App]
-  /// listens to this and opens the chat, then resets it to null.
-  static final ValueNotifier<String?> pendingChatToken = ValueNotifier(null);
-
-  /// Newsletter id of the most recently tapped Marianum-Message notification,
-  /// or null. [App] listens to this and opens the message, then resets it.
-  static final ValueNotifier<String?> pendingNewsletterId = ValueNotifier(null);
+  /// Target of the most recently tapped notification, or null. [App] listens
+  /// to this and navigates, then resets it to null.
+  static final ValueNotifier<PushTarget?> pendingTarget = ValueNotifier(null);
 
   static void handleResponse(NotificationResponse response) {
     final actionId = response.actionId;
@@ -29,13 +27,28 @@ class PushTapRouter {
     }
     final map = _payloadMap(response.payload);
     if (map == null) return;
-    final newsletterId = _stringValue(map, 'newsletterId');
-    if (newsletterId != null) {
-      pendingNewsletterId.value = newsletterId;
-      return;
+    final target = resolvePushTarget(map);
+    if (target != null) pendingTarget.value = target;
+  }
+
+  static bool _launchHandled = false;
+
+  /// Routes the tap that cold-started the app. The plugin reports such a tap
+  /// only through its launch details, never through the response callback;
+  /// the details stay set for the whole process, hence the one-shot guard.
+  static Future<void> handleAppLaunch(
+    FlutterLocalNotificationsPlugin plugin,
+  ) async {
+    if (_launchHandled) return;
+    _launchHandled = true;
+    try {
+      final details = await plugin.getNotificationAppLaunchDetails();
+      final response = details?.notificationResponse;
+      if (details?.didNotificationLaunchApp != true || response == null) return;
+      handleResponse(response);
+    } on Object catch (e) {
+      log('Reading the notification launch details failed: $e');
     }
-    final token = _stringValue(map, 'chatToken');
-    if (token != null) pendingChatToken.value = token;
   }
 
   static Map<String, dynamic>? _payloadMap(String? payload) {
@@ -46,9 +59,4 @@ class PushTapRouter {
       return null;
     }
   }
-
-  static String? _stringValue(Map<String, dynamic> map, String key) {
-    final value = map[key];
-    return value is String && value.isNotEmpty ? value : null;
-  }
 }