improve UP timeout behavior

Hopefully more reliable.

lib/controllers/unified_push.dart

@@ -18,6 +18,8 @@ import "package:unifiedpush_storage_shared_preferences/storage.dart";
 import "package:window_manager/window_manager.dart";
 
 class UnifiedPushController extends AsyncNotifier<bool> {
+  Completer<void>? _endpoint;
+
   @override
   Future<bool> build() async {
     if (!Platform.isLinux && !Platform.isAndroid) return false;
@@ -30,6 +32,7 @@ class UnifiedPushController extends AsyncNotifier<bool> {
         shouldWriteService: false,
       ),
       onNewEndpoint: (endpoint, instance) async {
+        final task = Future(() async {
           final pushKey = endpoint.pubKeySet!.pubKey;
           await ref
               .read(PushKeyController.provider(instance).notifier)
@@ -54,9 +57,20 @@ class UnifiedPushController extends AsyncNotifier<bool> {
               );
 
           state = .data(true);
+        });
+
+        if (_endpoint case final completer? when !completer.isCompleted) {
+          completer.complete(task);
+        } else {
+          await task;
+        }
       },
       onRegistrationFailed: (reason, instance) {
+        if (_endpoint case final completer? when !completer.isCompleted) {
+          completer.completeError(reason);
+        } else {
           throw reason;
+        }
       },
       onMessage: (message, instance) async {
         debugPrint("UP message received for $instance");
@@ -111,27 +125,34 @@ class UnifiedPushController extends AsyncNotifier<bool> {
       onUnregistered: deregister,
     );
 
-    ref.listen(
-      ClientStateController.provider.select((value) => value?.deviceId),
-      (_, _) => register(),
-    );
+    if (!registered) return false;
 
-    if (registered) {
-      // Needs to be registered every startup
-      await register();
+    try {
+      return await register();
+    } catch (error, stackTrace) {
+      showError(error, stackTrace);
+      return false;
+    }
   }
 
-    return registered;
-  }
-
-  Future<void> register() async {
+  Future<bool> register() async {
     state = .loading();
     try {
-      final deviceId = ref.read(
+      final deviceIdCompleter = Completer<String>();
+      final subscription = ref.listen(
         ClientStateController.provider.select((value) => value?.deviceId),
+        (_, next) {
+          if (next != null && !deviceIdCompleter.isCompleted) {
+            deviceIdCompleter.complete(next);
+          }
+        },
+        fireImmediately: true,
+      );
+      final deviceId = await deviceIdCompleter.future.whenComplete(
+        subscription.close,
       );
-      if (deviceId == null) return;
 
+      await Future(() async {
         final capabilities = await ref
             .read(ClientController.provider.notifier)
             .getCapabilities();
@@ -146,13 +167,26 @@ class UnifiedPushController extends AsyncNotifier<bool> {
           throw Exception("No UnifiedPush distributors found.");
         }
 
-      await UnifiedPush.register(
+        final endpoint = _endpoint = Completer<void>();
+
+        try {
+          await Future.wait([
+            UnifiedPush.register(
               instance: deviceId,
               vapid: capabilities.webpush?.vapid,
-      ).timeout(
-        .new(seconds: 15),
+            ),
+            endpoint.future,
+          ], eagerError: true);
+        } finally {
+          if (_endpoint == endpoint) _endpoint = null;
+        }
+      }).timeout(
+        .new(seconds: 10),
         onTimeout: () => throw Exception("UnifiedPush registration timed out."),
       );
+
+      state = .data(true);
+      return true;
     } catch (_) {
       state = .data(false);
       rethrow;

lib/controllers/unified_push_allowed.dart

@@ -7,7 +7,11 @@ import "package:unifiedpush/unifiedpush.dart";
 class UnifiedPushAllowedController extends AsyncNotifier<String?> {
   @override
   Future<String?> build() async {
-    if (!await UnifiedPush.tryUseCurrentOrDefaultDistributor()) {
+    if (!await UnifiedPush.tryUseCurrentOrDefaultDistributor().timeout(
+      .new(seconds: 10),
+      onTimeout: () =>
+          throw Exception("UnifiedPush distributor check timed out."),
+    )) {
       return "No valid distributors found. ${Platform.isLinux
           ? "Try installing KUnifiedPush"
           : Platform.isAndroid