feat: mentions badge in chat list and muted-mention delivery

app/chats/service.py

@@ -30,7 +30,13 @@ from app.realtime.presence import get_users_online_map
 from app.users.repository import get_user_by_id, has_block_relation_between_users
 
 
-async def serialize_chat_for_user(db: AsyncSession, *, user_id: int, chat: Chat) -> ChatRead:
+async def serialize_chat_for_user(
+    db: AsyncSession,
+    *,
+    user_id: int,
+    chat: Chat,
+    current_username: str | None = None,
+) -> ChatRead:
     display_title = chat.title
     my_role = None
     membership = await repository.get_chat_member(db, chat_id=chat.id, user_id=user_id)
@@ -66,7 +72,16 @@ async def serialize_chat_for_user(db: AsyncSession, *, user_id: int, chat: Chat)
         if chat.type == ChatType.CHANNEL:
             subscribers_count = members_count
 
+    if not current_username:
+        current_user = await get_user_by_id(db, user_id)
+        current_username = current_user.username if current_user else None
     unread_count = await repository.get_unread_count_for_chat(db, chat_id=chat.id, user_id=user_id)
+    unread_mentions_count = await repository.get_unread_mentions_count_for_chat(
+        db,
+        chat_id=chat.id,
+        user_id=user_id,
+        username=current_username,
+    )
     last_message = await repository.get_last_visible_message_for_user(db, chat_id=chat.id, user_id=user_id)
     user_setting = await repository.get_chat_user_setting(db, chat_id=chat.id, user_id=user_id)
     archived = bool(user_setting and user_setting.archived)
@@ -86,6 +101,7 @@ async def serialize_chat_for_user(db: AsyncSession, *, user_id: int, chat: Chat)
             "archived": archived,
             "pinned": pinned,
             "unread_count": unread_count,
+            "unread_mentions_count": unread_mentions_count,
             "pinned_message_id": chat.pinned_message_id,
             "members_count": members_count,
             "online_count": online_count,
@@ -105,7 +121,12 @@ async def serialize_chat_for_user(db: AsyncSession, *, user_id: int, chat: Chat)
 
 
 async def serialize_chats_for_user(db: AsyncSession, *, user_id: int, chats: list[Chat]) -> list[ChatRead]:
-    return [await serialize_chat_for_user(db, user_id=user_id, chat=chat) for chat in chats]
+    current_user = await get_user_by_id(db, user_id)
+    current_username = current_user.username if current_user else None
+    return [
+        await serialize_chat_for_user(db, user_id=user_id, chat=chat, current_username=current_username)
+        for chat in chats
+    ]
 
 
 async def create_chat_for_user(db: AsyncSession, *, creator_id: int, payload: ChatCreateRequest) -> Chat: