IM/src/main/java/com/zhentao/information/controller/MessageController.java

package com.zhentao.information.controller;

import com.alibaba.fastjson.JSON;
import com.zhentao.information.entity.ChatMessage;
import com.zhentao.information.entity.Message;
import com.zhentao.information.handler.WebSocketHandler;
import com.zhentao.information.repository.ChatMessageRepository;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.*;

import javax.annotation.Resource;
import java.util.List;
import java.util.Map;

/**
 * 消息控制器
 */
@Slf4j
@RestController
@RequestMapping("/api/message")
public class MessageController {

    @Resource
    private WebSocketHandler webSocketHandler;

    @Resource
    private ChatMessageRepository chatMessageRepository;

    /**
     * 发送消息接口
     */
    @PostMapping("/send")
    public String sendMessage(@RequestBody Message message) {
        log.info("收到消息：发送者={}, 接收者={}, 内容={}",
                message.getFromUserId(),
                message.getToUserId(),
                message.getContent());

        // 生成聊天ID（确保两个用户之间的聊天ID唯一）
        String chatId = generateChatId(message.getFromUserId(), message.getToUserId());

        // 创建MongoDB消息对象
        ChatMessage chatMessage = new ChatMessage();
        chatMessage.setFromUserId(message.getFromUserId());
        chatMessage.setToUserId(message.getToUserId());
        chatMessage.setContent(message.getContent());
        chatMessage.setType(message.getType());
        chatMessage.setTimestamp(System.currentTimeMillis());
        chatMessage.setIsRead(false);
        chatMessage.setChatId(chatId);

        // 保存消息到MongoDB
        chatMessageRepository.save(chatMessage);

        // 获取接收者的Channel
        Map<String, ChannelHandlerContext> userChannelMap = webSocketHandler.getUserChannelMap();
        ChannelHandlerContext toUserCtx = userChannelMap.get(message.getToUserId());

        if (toUserCtx != null) {
            // 发送消息给接收者
            toUserCtx.channel().writeAndFlush(new TextWebSocketFrame(JSON.toJSONString(message)));
            return "消息已发送";
        } else {
            return "消息已保存，等待接收者上线";
        }
    }

    /**
     * 获取两个用户之间的聊天记录
     */
    @GetMapping("/history")
    public List<ChatMessage> getChatHistory(@RequestParam String userId1, @RequestParam String userId2) {
        String chatId = generateChatId(userId1, userId2);
        return chatMessageRepository.findByChatId(chatId);
    }

    /**
     * 获取用户的未读消息
     */
    @GetMapping("/unread")
    public List<ChatMessage> getUnreadMessages(@RequestParam String userId) {
        return chatMessageRepository.findByToUserIdAndIsReadFalse(userId);
    }

    /**
     * 生成聊天ID
     */
    private String generateChatId(String userId1, String userId2) {
        // 确保两个用户之间的聊天ID唯一，且与顺序无关
        return userId1.compareTo(userId2) < 0 ?
                userId1 + "_" + userId2 :
                userId2 + "_" + userId1;
    }
}