feat(stream_chat_v1): open channel on foreground notification press

packages/stream_chat_v1/lib/notifications_service.dart

@@ -1,11 +1,16 @@
+import 'package:example/channel_page.dart';
 import 'package:example/localizations.dart';
+import 'package:example/routes/routes.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_local_notifications/flutter_local_notifications.dart'
     hide Message;
 import 'package:stream_chat_flutter/stream_chat_flutter.dart';
 
 void showLocalNotification(
-    Event event, String currentUserId, BuildContext context) async {
+  Event event,
+  String currentUserId,
+  BuildContext context,
+) async {
   if (![
         EventType.messageNew,
         EventType.notificationMessageNew,
@@ -22,7 +27,34 @@ void showLocalNotification(
     android: initializationSettingsAndroid,
     iOS: initializationSettingsIOS,
   );
-  await flutterLocalNotificationsPlugin.initialize(initializationSettings);
+  await flutterLocalNotificationsPlugin.initialize(
+    initializationSettings,
+    onSelectNotification: (channelCid) async {
+      if (channelCid != null) {
+        final client = StreamChat.of(context).client;
+        var channel = client.state.channels[channelCid];
+
+        if (channel == null) {
+          final splits = channelCid.split(':');
+          final type = splits[0];
+          final id = splits[1];
+          channel = client.channel(
+            type,
+            id: id,
+          );
+          await channel.watch();
+        }
+
+        Navigator.pushNamed(
+          context,
+          Routes.CHANNEL_PAGE,
+          arguments: ChannelPageArgs(
+            channel: channel,
+          ),
+        );
+      }
+    },
+  );
   await flutterLocalNotificationsPlugin.show(
     event.message!.id.hashCode,
     event.message!.user!.name,
@@ -37,5 +69,6 @@ void showLocalNotification(
       ),
       iOS: IOSNotificationDetails(),
     ),
+    payload: '${event.channelType}:${event.channelId}',
   );
 }