feat(notifications): add notification feed and mark as read/seen

This commit introduces a notification feed to the sample app and implements the ability to mark notifications as read or seen.

Key changes:

- **Notification Feed UI:**
    - Added `NotificationFeed` widget to display a list of aggregated notifications.
    - Added `NotificationItem` widget to render individual notification items with icons, text, and an unread indicator.
    - Integrated the notification feed into the `UserFeedScreen` accessible via a new notification icon in the app bar, which displays a badge for unseen notifications.
    - Notifications can be marked as read by tapping on them or by using a "Mark all read" button.
    - Notifications are automatically marked as seen when the notification feed is opened.
- **Mark Activity Logic:**
    - Implemented `onActivityMarked` in `FeedNotifier` to update the `FeedState` when activities are marked as read or seen.
    - Added helper methods (`_markAllRead`, `_markAllSeen`, `_markRead`, `_markSeen`) in `FeedNotifier` to handle different marking scenarios and update `NotificationStatusResponse`.
    - Introduced `MarkActivityDataHandler` extension on `MarkActivityData` to simplify handling different mark operations.
- **Styling and Refinements:**
    - Refactored `ActionButton` to always display the count and use `TextButton.icon`. Removed the `showCountWhenZero` property.
    - Updated `AppTextTheme` for `bodyBold` to use `FontWeight.w500`.
    - Used `switch` expressions for icon selection in `ActivityContent` and `NotificationItem`.
- **Exports:** Added `AggregatedActivityData`, `FeedMemberData`, and `FollowData` to `models.dart`.
- **Feed Repository:** Ensured `aggregatedActivities` in `GetOrCreateFeedData` are sorted.

Author: xsahil03x

packages/stream_feeds/lib/src/models.dart

@@ -1,9 +1,12 @@
 export 'models/activity_data.dart';
+export 'models/aggregated_activity_data.dart';
 export 'models/feed_data.dart';
 export 'models/feed_id.dart';
 export 'models/feed_input_data.dart';
+export 'models/feed_member_data.dart';
 export 'models/feed_member_request_data.dart';
 export 'models/feeds_config.dart';
+export 'models/follow_data.dart';
 export 'models/poll_data.dart';
 export 'models/request/activity_add_comment_request.dart'
     show ActivityAddCommentRequest;

packages/stream_feeds/lib/src/models/mark_activity_data.dart

@@ -45,6 +45,39 @@ class MarkActivityData with _$MarkActivityData {
   final List<String>? markWatched;
 }
 
+extension MarkActivityDataHandler<R> on MarkActivityData {
+  R handle({
+    R Function()? markAllRead,
+    R Function()? markAllSeen,
+    R Function(Set<String> read)? markRead,
+    R Function(Set<String> seen)? markSeen,
+    R Function(Set<String> watched)? markWatched,
+    required R Function(MarkActivityData data) orElse,
+  }) {
+    if (this.markAllRead case true) {
+      return markAllRead?.call() ?? orElse(this);
+    }
+
+    if (this.markAllSeen case true) {
+      return markAllSeen?.call() ?? orElse(this);
+    }
+
+    if (this.markRead case final read?) {
+      return markRead?.call(read.toSet()) ?? orElse(this);
+    }
+
+    if (this.markSeen case final seen?) {
+      return markSeen?.call(seen.toSet()) ?? orElse(this);
+    }
+
+    if (this.markWatched case final watched?) {
+      return markWatched?.call(watched.toSet()) ?? orElse(this);
+    }
+
+    return orElse(this);
+  }
+}
+
 /// Extension function to convert an [ActivityMarkEvent] to a [MarkActivityData] model.
 extension ActivityMarkEventMapper on ActivityMarkEvent {
   /// Converts this API activity mark event to a domain [MarkActivityData] instance.

packages/stream_feeds/lib/src/repository/feeds_repository.dart

@@ -1,8 +1,10 @@
+import 'package:collection/collection.dart';
 import 'package:stream_core/stream_core.dart';
 
 import '../generated/api/api.dart' as api;
 import '../models/activity_data.dart';
 import '../models/activity_pin_data.dart';
+import '../models/aggregated_activity_data.dart';
 import '../models/feed_data.dart';
 import '../models/feed_id.dart';
 import '../models/feed_member_data.dart';
@@ -54,7 +56,9 @@ class FeedsRepository {
 
       return GetOrCreateFeedData(
         activities: PaginationResult(
-          items: response.activities.map((a) => a.toModel()).toList(),
+          items: response.activities
+              .map((a) => a.toModel())
+              .sorted(ActivitiesSort.defaultSort.compare),
           pagination: PaginationData(
             next: response.next,
             previous: response.prev,
@@ -78,6 +82,9 @@ class FeedsRepository {
         ownCapabilities: response.ownCapabilities,
         pinnedActivities:
             response.pinnedActivities.map((a) => a.toModel()).toList(),
+        aggregatedActivities:
+            response.aggregatedActivities.map((a) => a.toModel()).toList(),
+        notificationStatus: response.notificationStatus,
       );
     });
   }

packages/stream_feeds/lib/src/state/feed_state.dart

@@ -1,3 +1,5 @@
+import 'dart:math';
+
 import 'package:collection/collection.dart';
 import 'package:freezed_annotation/freezed_annotation.dart';
 import 'package:state_notifier/state_notifier.dart';
@@ -177,14 +179,19 @@ class FeedStateNotifier extends StateNotifier<FeedState> {
 
   /// Handles updates to the feed state when an activity is marked read or seen.
   void onActivityMarked(MarkActivityData markData) {
-    // TODO: Handle activity marking (read/seen/watched) operations
-
-    // Note: The mark data contains information about:
-    // - markAllRead: Whether all activities should be marked as read
-    // - markAllSeen: Whether all activities should be marked as seen
-    // - markRead: List of specific activity IDs marked as read
-    // - markSeen: List of specific activity IDs marked as seen
-    // - markWatched: List of specific activity IDs marked as watched
+    // Update the state based on the type of mark operation
+    state = markData.handle(
+      // If markAllRead is true, mark all activities as read
+      markAllRead: () => _markAllRead(state),
+      // If markAllSeen is true, mark all activities as seen
+      markAllSeen: () => _markAllSeen(state),
+      // If markRead contains specific IDs, mark those as read
+      markRead: (read) => _markRead(read, state),
+      // If markSeen contains specific IDs, mark those as seen
+      markSeen: (seen) => _markSeen(seen, state),
+      // For other cases, return the current state without changes
+      orElse: (MarkActivityData data) => state,
+    );
   }
 
   /// Handles updates to the feed state when a bookmark is added or removed.
@@ -376,6 +383,68 @@ class FeedStateNotifier extends StateNotifier<FeedState> {
     return _addFollow(follow, removedFollowState);
   }
 
+  FeedState _markAllRead(FeedState state) {
+    final aggregatedActivities = state.aggregatedActivities;
+    final readActivities = aggregatedActivities.map((it) => it.group).toList();
+
+    // Set unread count to 0 and update read activities
+    final updatedNotificationStatus = state.notificationStatus?.copyWith(
+      unread: 0,
+      readActivities: readActivities,
+      lastReadAt: DateTime.timestamp(),
+    );
+
+    return state.copyWith(notificationStatus: updatedNotificationStatus);
+  }
+
+  FeedState _markAllSeen(FeedState state) {
+    final aggregatedActivities = state.aggregatedActivities;
+    final seenActivities = aggregatedActivities.map((it) => it.group).toList();
+
+    // Set unseen count to 0 and update seen activities
+    final updatedNotificationStatus = state.notificationStatus?.copyWith(
+      unseen: 0,
+      seenActivities: seenActivities,
+      lastSeenAt: DateTime.timestamp(),
+    );
+
+    return state.copyWith(notificationStatus: updatedNotificationStatus);
+  }
+
+  FeedState _markRead(Set<String> readIds, FeedState state) {
+    final readActivities = state.notificationStatus?.readActivities?.toSet();
+    final updatedReadActivities = readActivities?.union(readIds).toList();
+
+    // Decrease unread count by the number of newly read activities
+    final unreadCount = state.notificationStatus?.unread ?? 0;
+    final updatedUnreadCount = max(unreadCount - readIds.length, 0);
+
+    final updatedNotificationStatus = state.notificationStatus?.copyWith(
+      unread: updatedUnreadCount,
+      readActivities: updatedReadActivities,
+      lastReadAt: DateTime.timestamp(),
+    );
+
+    return state.copyWith(notificationStatus: updatedNotificationStatus);
+  }
+
+  FeedState _markSeen(Set<String> seenIds, FeedState state) {
+    final seenActivities = state.notificationStatus?.seenActivities?.toSet();
+    final updatedSeenActivities = seenActivities?.union(seenIds).toList();
+
+    // Decrease unseen count by the number of newly seen activities
+    final unseenCount = state.notificationStatus?.unseen ?? 0;
+    final updatedUnseenCount = max(unseenCount - seenIds.length, 0);
+
+    final updatedNotificationStatus = state.notificationStatus?.copyWith(
+      unseen: updatedUnseenCount,
+      seenActivities: updatedSeenActivities,
+      lastSeenAt: DateTime.timestamp(),
+    );
+
+    return state.copyWith(notificationStatus: updatedNotificationStatus);
+  }
+
   @override
   void dispose() {
     _removeMemberListListener?.call();