package com.yaoyuan.jiscuss.service; import com.yaoyuan.jiscuss.entity.Message; import java.util.List; public interface IMessageService { /** Send a message from sender to receiver. */ Message send(Integer senderId, Integer receiverId, String content); /** All messages in a conversation (ordered oldest→newest). */ List getConversation(Integer userId, Integer otherId); /** Inbox: latest message per conversation, sorted by latest activity (max 50). */ List getInbox(Integer userId); /** Unread message count for a user. */ long countUnread(Integer userId); /** Mark an entire conversation as read for the current user. */ void markConversationRead(Integer userId, Integer otherId); }