OAuth session persists via DPAPI; sign-in lives in the Start Stream dialog; add xUnit test project (6 passing)

ViewModels/MainViewModel.cs

@@ -126,18 +126,14 @@ public class MainViewModel : ViewModelBase
         set
         {
             if (SetProperty(ref _isConnected, value))
-            {
-                OnPropertyChanged(nameof(IsNotConnected));
                 OnPropertyChanged(nameof(ShowStartStream));
-            }
         }
     }
 
     public bool IsOffline => StreamStatus == StreamStatus.Offline;
     public bool IsLive => StreamStatus == StreamStatus.Streaming;
     public bool LiveIndicatorVisible => IsLive;
-    public bool IsNotConnected => !IsConnected;
-    public bool ShowStartStream => IsConnected && IsOffline;
+    public bool ShowStartStream => IsOffline;
     public bool ShowChatInactiveMessage => !IsLive;
     public bool ShowEmptySceneHint => ActiveScene != null && ActiveScene.Sources.Count == 0;
     public bool ShowPreviewPlaceholder => !ShowEmptySceneHint && ActiveBackgroundImage == null;
@@ -406,7 +402,6 @@ public class MainViewModel : ViewModelBase
     public ICommand AddSourceCommand { get; }
     public ICommand AddImageCommand { get; }
     public ICommand RemoveSourceCommand { get; }
-    public ICommand ConnectCommand { get; }
     public ICommand StartStreamCommand { get; }
     public ICommand EndStreamCommand { get; }
     public ICommand OpenSettingsCommand { get; }
@@ -424,7 +419,8 @@ public class MainViewModel : ViewModelBase
     public MainViewModel()
     {
         AppLog.Write("MainViewModel ctor begin");
-        _youtubeAuth = new YouTubeAuthService(OAuthCredentials.ClientId, OAuthCredentials.ClientSecret);
+        _youtubeAuth = new YouTubeAuthService(OAuthCredentials.ClientId, OAuthCredentials.ClientSecret,
+            sessionChanged: ch => TokenStore.Save(ch));
         _youtubeStream = new YouTubeStreamService(_youtubeAuth);
         _youtubeChat = new YouTubeChatService(_youtubeAuth);
         AppLog.Write("MainViewModel ctor: services created");
@@ -462,7 +458,6 @@ public class MainViewModel : ViewModelBase
         SubmitBugCommand = new RelayCommand(_ => SubmitBug());
         SubmitFeatureCommand = new RelayCommand(_ => SubmitFeature());
         OpenChannelCommand = new RelayCommand(_ => OpenUrl(ChannelUrl));
-        ConnectCommand = new RelayCommand(_ => _ = ConnectAsync());
         StartStreamCommand = new RelayCommand(_ => BeginGoLive());
         EndStreamCommand = new RelayCommand(_ => StopStream(), _ => IsLive);
         SaveLayoutCommand = new RelayCommand(_ => SaveLayoutNow());
@@ -472,9 +467,40 @@ public class MainViewModel : ViewModelBase
         _layoutStore = new LayoutStore(DefaultLayoutPath);
         _activeLayoutPath = _layoutStore.ActivePath;
         LoadLayout();
+        _ = LoadSavedSessionAsync();
         AppLog.Write("MainViewModel ctor end");
     }
 
+    // Restores the DPAPI-saved OAuth session so sign-in survives restarts.
+    // Best-effort: refresh a near-expiry access token; a session that can no
+    // longer refresh is discarded and the user signs in again.
+    private async Task LoadSavedSessionAsync()
+    {
+        try
+        {
+            var saved = TokenStore.Load();
+            if (saved == null) return;
+
+            _youtubeAuth.SetSession(saved);
+            if (saved.TokenExpiry <= DateTime.UtcNow.AddMinutes(5))
+            {
+                var refreshed = await Task.Run(() => _youtubeAuth.RefreshToken());
+                if (!refreshed)
+                {
+                    TokenStore.Clear();
+                    AppLog.Write("Saved session could not be refreshed; signed out");
+                    return;
+                }
+            }
+
+            IsConnected = true;
+        }
+        catch (Exception ex)
+        {
+            AppLog.Write($"LoadSavedSessionAsync failed: {ex}");
+        }
+    }
+
     private static string DefaultLayoutPath => Path.Combine(
         Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
         "ytLlive",
@@ -870,7 +896,10 @@ public class MainViewModel : ViewModelBase
         Process.Start(new ProcessStartInfo(url) { UseShellExecute = true });
     }
 
-    private async Task ConnectAsync()
+    // Runs the OAuth flow (browser + loopback callback) on a background thread.
+    // The resulting channel is returned to the caller and persisted via the
+    // auth service's sessionChanged hook.
+    private async Task<YouTubeChannel?> SignInAsync()
     {
         try
         {
@@ -879,15 +908,17 @@ public class MainViewModel : ViewModelBase
             {
                 MessageBox.Show("Sign-in was unsuccessful. Please try again.", "ytLlive",
                     MessageBoxButton.OK, MessageBoxImage.Warning);
-                return;
+                return null;
             }
 
             IsConnected = true;
+            return channel;
         }
         catch (Exception ex)
         {
             MessageBox.Show($"Sign-in failed: {ex.Message}", "ytLlive",
                 MessageBoxButton.OK, MessageBoxImage.Error);
+            return null;
         }
     }
 
@@ -903,7 +934,7 @@ public class MainViewModel : ViewModelBase
 
     private void BeginGoLive()
     {
-        var dialog = new GoLiveViewModel
+        var dialog = new GoLiveViewModel(() => SignInAsync(), _youtubeAuth.CurrentChannel)
         {
             StreamTitle = DefaultStreamTitle,
             StreamDescription = DefaultStreamDescription,