feat(chat): 聊天列表新增未读消息总数

core/routers/chat/services.py

@@ -40,6 +40,25 @@ async def get_user_active_direct_chats(
 
     return None
 
+async def get_total_unread_messages_count(db_session: AsyncSession, login_user: LoginUser) -> int:
+    """获取未读消息总数"""
+    query = (
+        select(func.count(Message.id))
+        .join(
+            ChatParticipant,
+            and_(
+                Message.chat_id == ChatParticipant.chat_id,
+                ChatParticipant.user_id == login_user.user_id
+            )
+        )
+        .filter(
+            Message.id > ChatParticipant.last_read_message_id,
+            Message.user_id != login_user.user_id,
+            ChatParticipant.is_deleted == False
+        )
+    )
+    result = await db_session.execute(query)
+    return result.scalar()
 
 async def get_chat_unread_messages_count(db_session: AsyncSession, login_user: LoginUser, chats):
     """查询未读消息的预览"""