event: Handle submessage event for polls.

We could potentially avoid notifying listeners in some cases when
handling submessage event, but it wouldn't be critically necessary.

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

lib/api/model/events.dart

@@ -2,6 +2,7 @@ import 'package:json_annotation/json_annotation.dart';
 
 import 'json.dart';
 import 'model.dart';
+import 'submessage.dart';
 
 part 'events.g.dart';
 
@@ -62,6 +63,7 @@ sealed class Event {
           case 'remove': return UpdateMessageFlagsRemoveEvent.fromJson(json);
           default: return UnexpectedEvent.fromJson(json);
         }
+      case 'submessage': return SubmessageEvent.fromJson(json);
       case 'typing': return TypingEvent.fromJson(json);
       case 'reaction': return ReactionEvent.fromJson(json);
       case 'heartbeat': return HeartbeatEvent.fromJson(json);
@@ -873,6 +875,38 @@ class UpdateMessageFlagsMessageDetail {
   Map<String, dynamic> toJson() => _$UpdateMessageFlagsMessageDetailToJson(this);
 }
 
+/// A Zulip event of type `submessage`: https://zulip.com/api/get-events#submessage
+@JsonSerializable(fieldRename: FieldRename.snake)
+class SubmessageEvent extends Event {
+  @override
+  @JsonKey(includeToJson: true)
+  String get type => 'submessage';
+
+  @JsonKey(unknownEnumValue: SubmessageType.unknown)
+  final SubmessageType msgType;
+  /// [SubmessageData] encoded in JSON.
+  @JsonKey(readValue: Submessage.readContent, toJson: Submessage.contentToJson)
+  final Object? content;
+  final int messageId;
+  final int senderId;
+  final int submessageId;
+
+  SubmessageEvent({
+    required super.id,
+    required this.msgType,
+    required this.content,
+    required this.messageId,
+    required this.senderId,
+    required this.submessageId,
+  });
+
+  factory SubmessageEvent.fromJson(Map<String, dynamic> json) =>
+    _$SubmessageEventFromJson(json);
+
+  @override
+  Map<String, dynamic> toJson() => _$SubmessageEventToJson(this);
+}
+
 /// A Zulip event of type `typing`:
 ///   https://zulip.com/api/get-events#typing-start
 ///   https://zulip.com/api/get-events#typing-stop

lib/api/model/events.g.dart

@@ -554,7 +554,7 @@ sealed class Message {
   }
 
   static Object? _pollToJson(Poll? poll) {
-    return null;
+    return poll?.submessages ?? [];
   }
 
   Message({

lib/api/model/model.dart

@@ -22,13 +22,13 @@ class Submessage {
   @JsonKey(unknownEnumValue: SubmessageType.unknown)
   final SubmessageType msgType;
   /// [SubmessageData] encoded in JSON.
-  @JsonKey(readValue: _readContent, toJson: _contentToJson)
+  @JsonKey(readValue: readContent, toJson: contentToJson)
   final Object? content;
   final int messageId;
   final int senderId;
   final int id;
 
-  static Object? _readContent(Map<Object?, Object?> json, String key) {
+  static Object? readContent(Map<Object?, Object?> json, String key) {
     try {
       return (const JsonDecoder().convert(json[key] as String)) as Object?;
     } catch (e) {
@@ -39,7 +39,7 @@ class Submessage {
     }
   }
 
-  static Object? _contentToJson(Object? content) =>
+  static Object? contentToJson(Object? content) =>
     const JsonEncoder().convert(content);
 
   factory Submessage.fromJson(Map<String, Object?> json) =>

lib/api/model/model.g.dart

@@ -6,6 +6,7 @@ import 'submessage.dart';
 /// - https://zulip.com/help/create-a-poll
 class Poll {
   Poll({
+    required this.submessages,
     required this.senderId,
     required this.question,
     required final List<String> options,
@@ -23,6 +24,7 @@ class Poll {
     final widgetEventSubmessages = submessages.sublist(1);
 
     final poll = Poll(
+      submessages: submessages,
       senderId: senderId,
       question: widgetData.extraData.question,
       options: widgetData.extraData.options,
@@ -35,6 +37,8 @@ class Poll {
     return poll;
   }
 
+  /// See [Message._pollToJson].
+  final List<Submessage> submessages;
   final int senderId;
   String question;
 

lib/api/model/submessage.dart

@@ -1,5 +1,6 @@
 import '../api/model/events.dart';
 import '../api/model/model.dart';
+import '../api/model/submessage.dart';
 import '../log.dart';
 import 'message_list.dart';
 
@@ -267,4 +268,17 @@ class MessageStoreImpl with MessageStore {
       view.notifyListenersIfMessagePresent(event.messageId);
     }
   }
+
+  void handleSubmessageEvent(SubmessageEvent event) {
+    final poll = messages[event.messageId]?.poll;
+    if (poll == null) return;
+    poll.applyEvent(
+      event.senderId,
+      PollEvent.fromJson(event.content as Map<String, Object?>)
+    );
+
+    for (final view in _messageListViews) {
+      view.notifyListenersIfMessagePresent(event.messageId);
+    }
+  }
 }

lib/api/model/submessage.g.dart

@@ -521,6 +521,10 @@ class PerAccountStore extends ChangeNotifier with ChannelStore, MessageStore {
         _messages.handleUpdateMessageFlagsEvent(event);
         unreads.handleUpdateMessageFlagsEvent(event);
 
+      case SubmessageEvent():
+        assert(debugLog("server event: submessage ${event.content}"));
+        _messages.handleSubmessageEvent(event);
+
       case TypingEvent():
         assert(debugLog("server event: typing/${event.op} ${event.messageType}"));
         typingStatus.handleTypingEvent(event);

lib/api/model/widget.dart

@@ -580,6 +580,21 @@ ReactionEvent reactionEvent(Reaction reaction, ReactionOp op, int messageId) {
   );
 }
 
+SubmessageEvent submessageEvent(
+  int messageId,
+  int senderId,
+  {required Object? content}
+) {
+  return SubmessageEvent(
+    id: 1,
+    msgType: SubmessageType.widget,
+    content: deepToJson(content),
+    messageId: messageId,
+    senderId: senderId,
+    submessageId: 1,
+  );
+}
+
 ////////////////////////////////////////////////////////////////
 // The entire per-account or global state.
 //