feat: import Chinese-localized Buzz source snapshot

Signed-off-by: cls_宁波本机 <908705107@qq.com>

mobile/lib/features/channels/unread_badge/observed_unread_event.dart

@@ -0,0 +1,133 @@
+import '../../../shared/read_state/read_state_format.dart';
+
+class ObservedUnreadEvent {
+  final String id;
+  final int createdAt;
+  final String? rootId;
+  final bool highPriority;
+  final bool countsTowardBadge;
+  final bool countsTowardAppBadge;
+
+  const ObservedUnreadEvent({
+    required this.id,
+    required this.createdAt,
+    required this.rootId,
+    required this.highPriority,
+    required this.countsTowardBadge,
+    required this.countsTowardAppBadge,
+  });
+}
+
+ObservedUnreadEvent makeObservedUnreadEvent({
+  required String id,
+  required int createdAt,
+  required String? rootId,
+  required bool highPriority,
+  required String? channelType,
+  required bool isThreadedReply,
+}) {
+  final isDm = channelType == 'dm';
+  return ObservedUnreadEvent(
+    id: id,
+    createdAt: createdAt,
+    rootId: rootId,
+    highPriority: highPriority,
+    countsTowardBadge: isDm || isThreadedReply || highPriority,
+    countsTowardAppBadge: isDm || (!isThreadedReply && highPriority),
+  );
+}
+
+bool recordObservedUnreadEvent(
+  Map<String, Map<String, ObservedUnreadEvent>> eventsByChannel,
+  String channelId,
+  ObservedUnreadEvent event,
+  int limit,
+) {
+  final eventsById = eventsByChannel.putIfAbsent(channelId, () => {});
+  if (eventsById.containsKey(event.id)) return false;
+
+  eventsById[event.id] = event;
+  if (eventsById.length <= limit) return true;
+
+  String? oldestId;
+  int? oldestCreatedAt;
+  for (final event in eventsById.values) {
+    if (oldestCreatedAt == null || event.createdAt < oldestCreatedAt) {
+      oldestCreatedAt = event.createdAt;
+      oldestId = event.id;
+    }
+  }
+  if (oldestId != null) {
+    eventsById.remove(oldestId);
+  }
+  return true;
+}
+
+int countUnreadObservedEvents(
+  Map<String, ObservedUnreadEvent>? eventsById,
+  int? Function(ObservedUnreadEvent event) getReadAt,
+) {
+  if (eventsById == null) return 0;
+  var count = 0;
+  for (final event in eventsById.values) {
+    final readAt = getReadAt(event);
+    if (readAt == null || event.createdAt > readAt) count++;
+  }
+  return count;
+}
+
+int countUnreadBadgeObservedEvents(
+  Map<String, ObservedUnreadEvent>? eventsById,
+  int? Function(ObservedUnreadEvent event) getReadAt,
+) {
+  if (eventsById == null) return 0;
+  var count = 0;
+  for (final event in eventsById.values) {
+    if (!event.countsTowardBadge) continue;
+    final readAt = getReadAt(event);
+    if (readAt == null || event.createdAt > readAt) count++;
+  }
+  return count;
+}
+
+int countUnreadAppBadgeObservedEvents(
+  Map<String, ObservedUnreadEvent>? eventsById,
+  int? Function(ObservedUnreadEvent event) getReadAt,
+) {
+  if (eventsById == null) return 0;
+  var count = 0;
+  for (final event in eventsById.values) {
+    if (!event.countsTowardAppBadge) continue;
+    final readAt = getReadAt(event);
+    if (readAt == null || event.createdAt > readAt) count++;
+  }
+  return count;
+}
+
+int countUnreadHighPriorityObservedEvents(
+  Map<String, ObservedUnreadEvent>? eventsById,
+  int? Function(ObservedUnreadEvent event) getReadAt,
+) {
+  if (eventsById == null) return 0;
+  var count = 0;
+  for (final event in eventsById.values) {
+    if (!event.highPriority) continue;
+    final readAt = getReadAt(event);
+    if (readAt == null || event.createdAt > readAt) count++;
+  }
+  return count;
+}
+
+int? observedUnreadEventReadAt(
+  ObservedUnreadEvent event,
+  int? channelReadAt,
+  int? Function(String rootId) getThreadOwnMarker,
+  int? Function(String messageId) getMessageOwnMarker,
+) {
+  final markers = <int?>[channelReadAt, getMessageOwnMarker(event.id)];
+  final rootId = event.rootId;
+  if (rootId != null) {
+    markers.add(getThreadOwnMarker(rootId));
+  }
+  return maxReadAt(markers);
+}