Notifications in groups, and what is unread

The Notifications tab reads grouped notifications (/api/v2/notifications):
likes and boosts of one post, or follows of one hour, are one card naming
both accounts of a pair, or the newest and how many others, with their
avatars. A notification the stream tells joins its group and waits on top.
The tab's badge counts what is unread; opening the tab moves the
notifications marker to the newest shown, which reads it on PrivaPub.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

Pages/Index.razor

@@ -18,7 +18,7 @@
 	</aside>
 
 	<section class="flex flex-col gap-3 min-h-0 flex-1 lg:h-full">
-		<FeedTabs Filter="Filter" Groups="groups" Lists="lists" Stats="FeedStats()" IsComposing="isComposing" OnCompose="() => isComposing = !isComposing"
+		<FeedTabs Filter="Filter" Groups="groups" Lists="lists" UnreadNotifications="unreadNotifications" Stats="FeedStats()" IsComposing="isComposing" OnCompose="() => isComposing = !isComposing"
 				  OnChanged="ChangeFeed" />
 
 		<div class="relative flex-1 min-h-0 neo-inset neo-xs rounded-xl">
@@ -115,6 +115,7 @@
 	List<FeedPost> pending = [];
 	List<ViewGroup> groups = [];
 	List<MastodonList> lists = [];
+	int unreadNotifications;
 	string maxId;
 	string minId;
 	string loadError;
@@ -245,6 +246,7 @@
 		minId = page.MinId;
 		lastPollAt = DateTime.UtcNow;
 		await Streaming.Follow(StreamOf(Filter), cancellationToken);
+		await ReadNotifications(cancellationToken);
 		StateHasChanged();
 		await Locate(posts, cancellationToken);
 		if (feedModule is not null)
@@ -329,6 +331,21 @@
 		}
 	}
 
+	/// <summary>On the Notifications tab, what is shown is read (the marker moves to the newest); elsewhere the tab's badge
+	/// counts what is unread.</summary>
+	async Task ReadNotifications(CancellationToken cancellationToken)
+	{
+		if (Filter.TimelineType is not TimelineType.Notifications)
+		{
+			unreadNotifications = await TimelineService.UnreadNotifications(cancellationToken);
+			return;
+		}
+		var newest = posts.Concat(pending).Select(p => p.Notification?.Id).Where(id => id is not null).Max(StringComparer.Ordinal);
+		if (newest is not null)
+			await TimelineService.ReadNotificationsUpTo(newest, cancellationToken);
+		unreadNotifications = 0;
+	}
+
 	/// <summary>The stream that tells this feed's new posts, or null for a feed PrivaPub does not stream.</summary>
 	static StreamSubscription StreamOf(FeedFilter filter) => filter.TimelineType switch
 	{
@@ -348,12 +365,29 @@
 		switch (message.Event)
 		{
 			case "update" when message.Status is { } status && Filter.TimelineType is not TimelineType.Notifications:
-			case "notification" when message.Notification is not null && Filter.TimelineType is TimelineType.Notifications:
-				var post = message.Status is { } s ? FeedPost.Of(s) : FeedPost.Of(message.Notification);
+				var post = FeedPost.Of(status);
 				if (posts.Concat(pending).Any(p => p.Key == post.Key))
 					return;
 				pending.Insert(0, post);
 				break;
+			case "notification" when message.Notification is { } notification && Filter.TimelineType is TimelineType.Notifications:
+				// a notification of a group already shown joins it, and the group waits on top as new
+				var key = notification.GroupKey ?? notification.Id;
+				var group = pending.FirstOrDefault(p => p.Key == key) ?? posts.FirstOrDefault(p => p.Key == key);
+				if (group is null)
+				{
+					pending.Insert(0, FeedPost.Of(notification));
+					break;
+				}
+				group.GroupCount++;
+				group.Notification = notification;
+				group.GroupAccounts = [.. group.GroupAccounts.Prepend(notification.Account).Where(a => a is not null).DistinctBy(a => a.Id).Take(8)];
+				if (posts.Remove(group))
+					pending.Insert(0, group);
+				break;
+			case "notification" when Filter.TimelineType is not TimelineType.Notifications:
+				unreadNotifications++;
+				break;
 			case "delete" when message.DeletedId is { } id:
 				posts.RemoveAll(p => p.Key == id || p.Status?.Id == id);
 				pending.RemoveAll(p => p.Key == id || p.Status?.Id == id);
@@ -373,6 +407,7 @@
 		var shown = pending;
 		pending = [];
 		posts.InsertRange(0, shown);
+		await ReadNotifications(loadCancellation?.Token ?? default);
 		minId = shown.FirstOrDefault()?.CursorId ?? minId;
 		await feedModule.InvokeVoidAsync("scrollToTop", ScrollId);
 		await Locate(shown, loadCancellation?.Token ?? default);