Update Broadcast button: diff before push, offline=local only, live=API; Go Live empty-field prompt

Models/BroadcastMetadata.cs

@@ -7,7 +7,7 @@ namespace ytLive.Models;
 /// the fields that stay mutable for the whole life of the broadcast. Fields
 /// that only exist pre-launch (scheduledStartTime, contentDetails) are NOT
 /// here by design; see ai.md "Broadcast metadata side pull-out".</summary>
-public sealed class BroadcastMetadata
+public sealed record BroadcastMetadata
 {
     public string Title { get; set; } = string.Empty;
     public string Description { get; set; } = string.Empty;

Services/LiveBroadcastFormViewModel.cs

@@ -21,6 +21,7 @@ public sealed class LiveBroadcastFormViewModel : ViewModelBase
     private readonly Func<LayoutStore> _store;
     private readonly Func<YouTubeStreamService?> _streamService;
     private readonly Func<string?> _broadcastId;
+    private readonly Func<bool> _isLive;
 
     private string _title = string.Empty;
     private string _description = string.Empty;
@@ -31,15 +32,18 @@ public sealed class LiveBroadcastFormViewModel : ViewModelBase
     private bool _isDrawerOpen;
     private bool _isUpdating;
     private string? _updateError;
+    private BroadcastMetadata? _lastSyncedSnapshot;
 
     public LiveBroadcastFormViewModel(
         Func<LayoutStore> store,
         Func<YouTubeStreamService?> streamService,
-        Func<string?> broadcastId)
+        Func<string?> broadcastId,
+        Func<bool>? isLive = null)
     {
         _store = store;
         _streamService = streamService;
         _broadcastId = broadcastId;
+        _isLive = isLive ?? (() => false);
         UpdateBroadcastCommand = new RelayCommand(_ => _ = UpdateRemoteAsync(), _ => CanUpdateRemote);
         ToggleDrawerCommand = new RelayCommand(_ => IsDrawerOpen = !IsDrawerOpen);
         CloseDrawerCommand = new RelayCommand(_ => IsDrawerOpen = false);
@@ -92,9 +96,10 @@ public sealed class LiveBroadcastFormViewModel : ViewModelBase
         private set => SetProperty(ref _updateError, value);
     }
 
-    public bool CanUpdateRemote => !string.IsNullOrEmpty(_broadcastId()) && !IsUpdating;
+    public bool CanUpdateRemote => !IsUpdating;
 
-    /// <summary>Pull everything from the store (startup / Go Live refresh).</summary>
+    /// <summary>Pull everything from the store (startup / Go Live refresh).
+    /// Seeds the synced snapshot so the next Update click knows what is already remote.</summary>
     public void Load()
     {
         var meta = _store().LoadBroadcastMetadata();
@@ -110,6 +115,7 @@ public sealed class LiveBroadcastFormViewModel : ViewModelBase
         OnPropertyChanged(nameof(Visibility));
         OnPropertyChanged(nameof(MadeForKids));
         OnPropertyChanged(nameof(ScheduledStartText));
+        SnapshotSynced();
     }
 
     /// <summary>Called at Go Live with what was actually inserted remotely.</summary>
@@ -119,6 +125,7 @@ public sealed class LiveBroadcastFormViewModel : ViewModelBase
         Description = description;
         ScheduledStartTime = scheduledStart;
         UpdateError = null;
+        SnapshotSynced();
     }
 
     public BroadcastMetadata ToMetadata() => new()
@@ -147,13 +154,36 @@ public sealed class LiveBroadcastFormViewModel : ViewModelBase
     {
         var id = _broadcastId();
         var service = _streamService();
-        if (id == null || service == null || IsUpdating) return;
+        if (IsUpdating) return;
         IsUpdating = true;
         UpdateError = null;
         try
         {
-            var error = await service.UpdateBroadcast(id, ToMetadata());
+            var current = ToMetadata();
+            if (!_isLive())
+            {
+                UpdateError = null;
+                IsDrawerOpen = false;
+                return;
+            }
+            if (id == null || service == null)
+            {
+                UpdateError = null;
+                IsDrawerOpen = false;
+                return;
+            }
+            if (_lastSyncedSnapshot != null && current.Equals(_lastSyncedSnapshot))
+            {
+                UpdateError = "No changes to update";
+                return;
+            }
+            var error = await service.UpdateBroadcast(id, current);
             UpdateError = error;
+            if (error == null)
+            {
+                SnapshotSynced();
+                IsDrawerOpen = false;
+            }
         }
         catch (Exception ex)
         {
@@ -165,4 +195,6 @@ public sealed class LiveBroadcastFormViewModel : ViewModelBase
             IsUpdating = false;
         }
     }
+
+    private void SnapshotSynced() => _lastSyncedSnapshot = ToMetadata();
 }

ViewModels/MainViewModel.cs

@@ -1565,7 +1565,8 @@ public class MainViewModel : ViewModelBase
         BroadcastForm = new Services.LiveBroadcastFormViewModel(
             () => _layoutStore,
             () => _youtubeStream,
-            () => CurrentBroadcastId);
+            () => CurrentBroadcastId,
+            () => IsLive);
 
         // Restore the last picked mic so the mixer's first capture attaches to
         // the same, already-vetted device (green dot) or reports it missing
@@ -2961,6 +2962,13 @@ public class MainViewModel : ViewModelBase
             AppLog.Write($"Broadcast created: {_currentBroadcastId}");
             OnPropertyChanged(nameof(CurrentBroadcastId));
 
+            if (string.IsNullOrWhiteSpace(StreamTitle) && string.IsNullOrWhiteSpace(StreamDescription))
+            {
+                BroadcastForm.IsDrawerOpen = true;
+                _notifications.Warning("Complete your broadcast details",
+                    "Your title and description are empty — fill them in from the Text panel on the right.");
+            }
+
             // Start chat polling (TASK 9.4): fetch the liveChatId from the broadcast's
             // contentDetails, then start the poll loop. Chat is non-fatal — if it fails,
             // the stream continues without on-panel chat.

ytLive.Tests/BroadcastPullOutTests.cs

@@ -142,6 +142,82 @@ public sealed class BroadcastPullOutTests
             Assert.True(root.GetProperty("status").GetProperty("selfDeclaredMadeForKids").GetBoolean());
             Assert.Equal(new DateTime(2026, 8, 24, 12, 0, 0, DateTimeKind.Utc).ToString("o"),
                 root.GetProperty("snippet").GetProperty("scheduledStartTime").GetString());
+
+            // --- Diff + close drawer tests ---
+
+            var auth2 = new YouTubeAuthService("test-client", "test-secret");
+            auth2.SetSession(new YouTubeChannel
+            {
+                AccessToken = "token2",
+                TokenExpiry = DateTime.UtcNow.AddHours(1),
+            });
+            var stub2 = new StubHandler();
+            var service2 = new YouTubeStreamService(auth2, new HttpClient(stub2));
+
+            string? broadcastId = "bc456";
+
+            // --- Offline path (isLive = false): saves locally, never pushes API ---
+            var formOffline = new LiveBroadcastFormViewModel(
+                () => new LayoutStore(tempDb),
+                () => service2,
+                () => broadcastId,
+                () => false);
+
+            formOffline.Load();
+            Assert.False(formOffline.IsDrawerOpen);
+
+            // No edits → stays open, no API call
+            formOffline.IsDrawerOpen = true;
+            formOffline.UpdateBroadcastCommand.Execute(null);
+            Assert.Null(stub2.Request);
+            Assert.False(formOffline.IsDrawerOpen);
+
+            // Edit Title → closes drawer, still no API call (offline = local save only)
+            stub2.Request = null;
+            formOffline.Title = "Changed offline";
+            formOffline.IsDrawerOpen = true;
+            formOffline.UpdateBroadcastCommand.Execute(null);
+            Assert.Null(stub2.Request);
+            Assert.False(formOffline.IsDrawerOpen);
+
+            // Re-load → the offline edit persisted to the store
+            formOffline.Load();
+            Assert.Equal("Changed offline", formOffline.Title);
+
+            // --- Live path (isLive = true): pushes to API ---
+            var formLive = new LiveBroadcastFormViewModel(
+                () => new LayoutStore(tempDb),
+                () => service2,
+                () => broadcastId,
+                () => true);
+
+            formLive.Load();
+            formLive.IsDrawerOpen = true;
+
+            // No edits → "No changes to update", stays open
+            stub2.Request = null;
+            formLive.UpdateBroadcastCommand.Execute(null);
+            Assert.Null(stub2.Request);
+            Assert.Equal("No changes to update", formLive.UpdateError);
+            Assert.True(formLive.IsDrawerOpen);
+
+            // Edit Title → HTTP PUT fires, drawer closes
+            stub2.Request = null;
+            formLive.Title = "Live update";
+            formLive.UpdateBroadcastCommand.Execute(null);
+            Assert.NotNull(stub2.Request);
+            Assert.Equal(HttpMethod.Put, stub2.Request!.Method);
+            Assert.Null(formLive.UpdateError);
+            Assert.False(formLive.IsDrawerOpen);
+
+            // Re-seed snapshot via Load, then edit again → second upload fires
+            stub2.Request = null;
+            formLive.Load();
+            formLive.Description = "Live desc";
+            formLive.UpdateBroadcastCommand.Execute(null);
+            Assert.NotNull(stub2.Request);
+            Assert.Null(formLive.UpdateError);
+            Assert.False(formLive.IsDrawerOpen);
         }
         finally
         {