v3: chatbox improvements (typing indicators, answer to previous messages, backlog days separators, scroll to last message position, visual tweaks)

src/model.ts

@@ -228,6 +228,13 @@ export interface ChatMessage {
   updatedAt?: Date;
   authorUsername: string;
   authorAvatarMime?: string;
+  /** Id of the message this one replies to, if any. Kept even when the target
+   * was deleted (the preview fields below then go undefined). */
+  replyToId?: string;
+  /** Author/snippet of the replied-to message, for a subtle inline reference.
+   * Absent when there's no reply, or the target has since been deleted. */
+  replyToAuthor?: string;
+  replyToBody?: string;
 }
 
 export type RawChatMessage = WithStringDate<ChatMessage>;
@@ -537,6 +544,11 @@ export interface WSChatMessageDeletedMessage {
   id: string;
 }
 
+export interface WSChatTypingUpdateMessage {
+  type: "chat_typing_update";
+  users: OnlineUser[];
+}
+
 export type IncomingWSMessage =
   | WSPingMessage
   | WSWelcomeMessage
@@ -561,7 +573,8 @@ export type IncomingWSMessage =
   | WSForceLogoutMessage
   | WSChatMessageMessage
   | WSChatMessageUpdatedMessage
-  | WSChatMessageDeletedMessage;
+  | WSChatMessageDeletedMessage
+  | WSChatTypingUpdateMessage;
 
 /**
  * WebSocket messages — client → server (outgoing)
@@ -590,6 +603,12 @@ export interface WSCommentLikeRemoveMessage {
 export interface WSChatSendMessage {
   type: "chat_send";
   body: string;
+  replyToId?: string;
+}
+
+export interface WSChatTypingMessage {
+  type: "chat_typing";
+  typing: boolean;
 }
 
 export interface WSChatFocusMessage {
@@ -615,6 +634,7 @@ export type OutgoingWSMessage =
   | WSCommentLikeCastMessage
   | WSCommentLikeRemoveMessage
   | WSChatSendMessage
+  | WSChatTypingMessage
   | WSChatFocusMessage
   | WSChatEditMessage
   | WSChatDeleteMessage;