init

lib/push.dart

@@ -0,0 +1,102 @@
+import 'dart:async';
+import 'dart:io';
+
+import 'package:firebase_messaging/firebase_messaging.dart';
+
+typedef FcmTokenCallback = Future<void> Function(String token, String platform);
+
+class PushService {
+  PushService({required this.firebaseReady});
+
+  final bool firebaseReady;
+  final _subscriptions = <StreamSubscription<dynamic>>[];
+  bool _listening = false;
+
+  Future<void> listen({
+    required void Function(String ticketId) onOpenTicket,
+    required void Function(RemoteMessage message) onForegroundMessage,
+    required FcmTokenCallback onToken,
+    required bool Function() isSignedIn,
+  }) async {
+    if (!firebaseReady || _listening) {
+      return;
+    }
+    _listening = true;
+    _subscriptions
+      ..add(
+        FirebaseMessaging.instance.onTokenRefresh.listen((token) async {
+          try {
+            if (!isSignedIn()) {
+              return;
+            }
+            final settings = await FirebaseMessaging.instance
+                .getNotificationSettings();
+            if (!_allowsNotifications(settings.authorizationStatus)) {
+              return;
+            }
+            await onToken(token, _platform);
+          } on Object {
+            // Keep the previous registration when a token refresh cannot be saved.
+          }
+        }),
+      )
+      ..add(FirebaseMessaging.onMessage.listen(onForegroundMessage))
+      ..add(
+        FirebaseMessaging.onMessageOpenedApp.listen((message) {
+          final ticketId = _ticketId(message);
+          if (ticketId != null) {
+            onOpenTicket(ticketId);
+          }
+        }),
+      );
+    try {
+      final initial = await FirebaseMessaging.instance.getInitialMessage();
+      if (initial != null) {
+        final ticketId = _ticketId(initial);
+        if (ticketId != null) {
+          onOpenTicket(ticketId);
+        }
+      }
+    } on Object {
+      // Opening from a notification can wait until the next tap.
+    }
+  }
+
+  Future<void> register(FcmTokenCallback onToken) async {
+    if (!firebaseReady) {
+      return;
+    }
+    try {
+      final settings = await FirebaseMessaging.instance.requestPermission(
+        alert: true,
+        badge: true,
+        sound: true,
+      );
+      if (!_allowsNotifications(settings.authorizationStatus)) {
+        return;
+      }
+      final token = await FirebaseMessaging.instance.getToken();
+      if (token == null || token.isEmpty) {
+        return;
+      }
+      await onToken(token, _platform);
+    } on Object {
+      // Denied permission or a missing Firebase file should not block the inbox.
+    }
+  }
+
+  String? _ticketId(RemoteMessage message) {
+    final value = message.data['ticketId'];
+    if (value is String && value.isNotEmpty) {
+      return value;
+    }
+    return null;
+  }
+
+  bool _allowsNotifications(AuthorizationStatus status) {
+    return status == AuthorizationStatus.authorized ||
+        status == AuthorizationStatus.provisional;
+  }
+
+  String get _platform => Platform.isIOS ? 'ios' : 'android';
+}