add partial background downloading and update prompt

Blueberry/MainWindow.xaml.cs

@@ -45,9 +45,35 @@ namespace BlueMine
                 Task getHoursTask = GetHours();
 
                 await Task.WhenAll(loadIssuesTask, getHoursTask);
+#if !DEBUG
+                if(await UpdateManager.IsUpdateAvailable())
+                {
+                    updateIcon.Visibility = Visibility.Visible;
+                    UpdateManager.DownloadCompleted += UpdateManager_DownloadCompleted;
+                    await UpdateManager.DownloadUpdateAsync();
+                }
+#endif
             }
         }
 
+        private async void UpdateManager_DownloadCompleted()
+        {
+            await Dispatcher.Invoke(async () =>
+            {
+                var result = await new Wpf.Ui.Controls.MessageBox
+                {
+                    Title = "Frissítés elérhető",
+                    Content = "Szeretnél most frissíteni?",
+                    PrimaryButtonText = "Frissítés",
+                    SecondaryButtonText = "Később",
+                    IsCloseButtonEnabled = false,
+                }.ShowDialogAsync();
+
+                if (result == Wpf.Ui.Controls.MessageBoxResult.Primary)
+                    await UpdateManager.PerformUpdate();
+            });
+        }
+
         private void CalendarButtonClicked(object sender, RoutedEventArgs e)
         {
             flyoutCalendar.IsOpen = true;