api: Add update_message_flags events

lib/api/model/events.dart

@@ -40,6 +40,12 @@ sealed class Event {
       case 'message': return MessageEvent.fromJson(json);
       case 'update_message': return UpdateMessageEvent.fromJson(json);
       case 'delete_message': return DeleteMessageEvent.fromJson(json);
+      case 'update_message_flags':
+        switch (json['op'] as String) {
+          case 'add': return UpdateMessageFlagsAddEvent.fromJson(json);
+          case 'remove': return UpdateMessageFlagsRemoveEvent.fromJson(json);
+          default: return UnexpectedEvent.fromJson(json);
+        }
       case 'reaction': return ReactionEvent.fromJson(json);
       case 'heartbeat': return HeartbeatEvent.fromJson(json);
       // TODO add many more event types
@@ -439,13 +445,122 @@ class DeleteMessageEvent extends Event {
   Map<String, dynamic> toJson() => _$DeleteMessageEventToJson(this);
 }
 
-/// As in [DeleteMessageEvent.messageType].
+/// As in [DeleteMessageEvent.messageType]
+/// or [UpdateMessageFlagsMessageDetail.type].
 @JsonEnum(fieldRename: FieldRename.snake)
 enum MessageType {
   stream,
   private;
 }
 
+/// A Zulip event of type `update_message_flags`.
+///
+/// For the corresponding API docs, see subclasses.
+sealed class UpdateMessageFlagsEvent extends Event {
+  @override
+  @JsonKey(includeToJson: true)
+  String get type => 'update_message_flags';
+
+  String get op;
+
+  @JsonKey(unknownEnumValue: MessageFlag.unknown)
+  final MessageFlag flag;
+  final List<int> messages;
+
+  UpdateMessageFlagsEvent({
+    required super.id,
+    required this.flag,
+    required this.messages,
+  });
+}
+
+/// An [UpdateMessageFlagsEvent] with op `add`: https://zulip.com/api/get-events#update_message_flags-add
+@JsonSerializable(fieldRename: FieldRename.snake)
+class UpdateMessageFlagsAddEvent extends UpdateMessageFlagsEvent {
+  @override
+  String get op => 'add';
+
+  final bool all;
+
+  UpdateMessageFlagsAddEvent({
+    required super.id,
+    required super.flag,
+    required super.messages,
+    required this.all,
+  });
+
+  factory UpdateMessageFlagsAddEvent.fromJson(Map<String, dynamic> json) =>
+    _$UpdateMessageFlagsAddEventFromJson(json);
+
+  @override
+  Map<String, dynamic> toJson() => _$UpdateMessageFlagsAddEventToJson(this);
+}
+
+/// An [UpdateMessageFlagsEvent] with op `remove`: https://zulip.com/api/get-events#update_message_flags-remove
+@JsonSerializable(fieldRename: FieldRename.snake)
+class UpdateMessageFlagsRemoveEvent extends UpdateMessageFlagsEvent {
+  @override
+  String get op => 'remove';
+
+  // final bool all; // deprecated, ignore
+  final Map<int, UpdateMessageFlagsMessageDetail>? messageDetails;
+
+  UpdateMessageFlagsRemoveEvent({
+    required super.id,
+    required super.flag,
+    required super.messages,
+    required this.messageDetails,
+  });
+
+  factory UpdateMessageFlagsRemoveEvent.fromJson(Map<String, dynamic> json) {
+    final result = _$UpdateMessageFlagsRemoveEventFromJson(json);
+    // Crunchy-shell validation
+    if (
+      result.flag == MessageFlag.read
+      && true // (we assume `event_types` has `message` and `update_message_flags`)
+    ) {
+      result.messageDetails as Map<int, UpdateMessageFlagsMessageDetail>;
+    }
+    return result;
+  }
+
+  @override
+  Map<String, dynamic> toJson() => _$UpdateMessageFlagsRemoveEventToJson(this);
+}
+
+/// As in [UpdateMessageFlagsRemoveEvent.messageDetails].
+@JsonSerializable(fieldRename: FieldRename.snake)
+class UpdateMessageFlagsMessageDetail {
+  final MessageType type;
+  final bool? mentioned;
+  final List<int>? userIds;
+  final int? streamId;
+  final String? topic;
+
+  UpdateMessageFlagsMessageDetail({
+    required this.type,
+    required this.mentioned,
+    required this.userIds,
+    required this.streamId,
+    required this.topic,
+  });
+
+  factory UpdateMessageFlagsMessageDetail.fromJson(Map<String, dynamic> json) {
+    final result = _$UpdateMessageFlagsMessageDetailFromJson(json);
+    // Crunchy-shell validation
+    switch (result.type) {
+      case MessageType.stream:
+        result.streamId as int;
+        result.topic as String;
+      case MessageType.private:
+        result.userIds as List<int>;
+    }
+    return result;
+  }
+
+  Map<String, dynamic> toJson() => _$UpdateMessageFlagsMessageDetailToJson(this);
+}
+
 /// A Zulip event of type `reaction`, with op `add` or `remove`.
 ///
 /// See:

lib/model/message_list.dart

@@ -420,6 +420,35 @@ class MessageListView with ChangeNotifier, _MessageSequence {
     notifyListeners();
   }
 
+  void maybeUpdateMessageFlags(UpdateMessageFlagsEvent event) {
+    final isAdd = switch (event) {
+      UpdateMessageFlagsAddEvent()    => true,
+      UpdateMessageFlagsRemoveEvent() => false,
+    };
+
+    bool didUpdateAny = false;
+    if (isAdd && (event as UpdateMessageFlagsAddEvent).all) {
+      for (final message in messages) {
+        message.flags.add(event.flag);
+        didUpdateAny = true;
+      }
+    } else {
+      for (final messageId in event.messages) {
+        final index = _findMessageWithId(messageId);
+        if (index != -1) {
+          final message = messages[index];
+          isAdd ? message.flags.add(event.flag) : message.flags.remove(event.flag);
+          didUpdateAny = true;
+        }
+      }
+    }
+    if (!didUpdateAny) {
+      return;
+    }
+
+    notifyListeners();
+  }
+
   void maybeUpdateMessageReactions(ReactionEvent event) {
     final index = _findMessageWithId(event.messageId);
     if (index == -1) {

lib/model/store.dart

@@ -309,6 +309,11 @@ class PerAccountStore extends ChangeNotifier {
     } else if (event is DeleteMessageEvent) {
       assert(debugLog("server event: delete_message ${event.messageIds}"));
       // TODO handle
+    } else if (event is UpdateMessageFlagsEvent) {
+      assert(debugLog("server event: update_message_flags/${event.op} ${event.flag.toJson()}"));
+      for (final view in _messageListViews) {
+        view.maybeUpdateMessageFlags(event);
+      }
     } else if (event is ReactionEvent) {
       assert(debugLog("server event: reaction/${event.op}"));
       for (final view in _messageListViews) {

test/api/model/events_test.dart

@@ -10,19 +10,6 @@ import 'events_checks.dart';
 import 'model_checks.dart';
 
 void main() {
-  test('message: move flags into message object', () {
-    final message = eg.streamMessage();
-    MessageEvent mkEvent(List<MessageFlag> flags) => Event.fromJson({
-      'type': 'message',
-      'id': 1,
-      'message': (deepToJson(message) as Map<String, dynamic>)..remove('flags'),
-      'flags': flags.map((f) => f.toJson()).toList(),
-    }) as MessageEvent;
-    check(mkEvent(message.flags)).message.jsonEquals(message);
-    check(mkEvent([])).message.flags.deepEquals([]);
-    check(mkEvent([MessageFlag.read])).message.flags.deepEquals([MessageFlag.read]);
-  });
-
   test('user_settings: all known settings have event handling', () {
     final dataClassFieldNames = UserSettings.debugKnownNames;
     final enumNames = UserSettingName.values.map((n) => n.name);
@@ -42,4 +29,35 @@ void main() {
         '      on the pattern of the existing cases.'
     ).isEmpty();
   });
+
+  test('message: move flags into message object', () {
+    final message = eg.streamMessage();
+    MessageEvent mkEvent(List<MessageFlag> flags) => Event.fromJson({
+      'type': 'message',
+      'id': 1,
+      'message': (deepToJson(message) as Map<String, dynamic>)..remove('flags'),
+      'flags': flags.map((f) => f.toJson()).toList(),
+    }) as MessageEvent;
+    check(mkEvent(message.flags)).message.jsonEquals(message);
+    check(mkEvent([])).message.flags.deepEquals([]);
+    check(mkEvent([MessageFlag.read])).message.flags.deepEquals([MessageFlag.read]);
+  });
+
+  test('update_message_flags/remove: require messageDetails in mark-as-unread', () {
+    final baseJson = {
+      'id': 1,
+      'type': 'update_message_flags',
+      'op': 'remove',
+      'flag': 'starred',
+      'messages': [123],
+      'all': false,
+    };
+    check(() => UpdateMessageFlagsRemoveEvent.fromJson(baseJson)).returnsNormally();
+    check(() => UpdateMessageFlagsRemoveEvent.fromJson({
+      ...baseJson, 'flag': 'read',
+    })).throws();
+    check(() => UpdateMessageFlagsRemoveEvent.fromJson({
+      ...baseJson, 'message_details': {'123': {'type': 'private', 'mentioned': false, 'user_ids': [2]}},
+    })).returnsNormally();
+  });
 }

test/example_data.dart

@@ -155,7 +155,7 @@ StreamMessage streamMessage({
   int? lastEditTimestamp,
   List<Reaction>? reactions,
   int? timestamp,
-  List<String>? flags,
+  List<MessageFlag>? flags,
 }) {
   final effectiveStream = stream ?? _stream();
   // The use of JSON here is convenient in order to delegate parts of the data
@@ -191,7 +191,7 @@ DmMessage dmMessage({
   String? contentMarkdown,
   int? lastEditTimestamp,
   int? timestamp,
-  List<String>? flags,
+  List<MessageFlag>? flags,
 }) {
   assert(!to.any((user) => user.userId == from.userId));
   return DmMessage.fromJson({