const WebSocket = require("ws");
const url = require("url");

const { verifyToken } = require("../utils/jwt");

const {
  addConnection,
  getConnection,
  removeConnection,
} = require("./connectionManager");

// 创建WebSocket服务
function initWebSocket(server) {
  const wss = new WebSocket.Server({
    server,
  });

  wss.on("connection", (ws, request) => {
    console.log("有新的WebSocket连接");

    // 获取URL中的token
    const query = url.parse(request.url, true).query;
    const token = query.token;

    if (!token) {
      console.log("没有提供token");
      ws.close();
      return;
    }

    // 验证JWT
    let user;
    try {
      user = verifyToken(token);
    } catch (error) {
      console.log("JWT验证失败：", error.message);
      ws.close();
      return;
    }
    console.log("WebSocket用户：", user);

    const username = user.username;
    // 保存连接
    addConnection(username, ws);

    // 接收客户端消息
    ws.on("message", (message) => {
      try {
        const data = JSON.parse(message.toString());
        console.log("收到WebSocket消息：", data);

        handleMessage(username, data);
      } catch (error) {
        console.error("WebSocket消息处理失败：", error);
      }
    });

    // 连接关闭
    ws.on("close", () => {
      removeConnection(username);
    });

    // WebSocket错误
    ws.on("error", (error) => {
      console.error(`用户 ${username} WebSocket错误：`, error);
    });
  });

  console.log("WebSocket服务已启动");

  return wss;
}

// 处理WebSocket消息
function handleMessage(username, data) {
  switch (data.type) {
    case "sendMessage":
      handleSendMessage(username, data);
      break;

    default:
      console.log("未知消息类型：", data.type);
  }
}

// 处理发送消息
function handleSendMessage(senderName, data) {
  const receiverName = data.receiverName;
  const content = data.content;
  const createdAt = data.createdAt;

  console.log(
    `${senderName} → ${receiverName}：${content}`
  );

  // 找到接收者的WebSocket
  const receiverWs = getConnection(receiverName);
  if (!receiverWs) {
    console.log(`${receiverName} 当前不在线`);
    return;
  }

  // 推送消息
  receiverWs.send(
    JSON.stringify({
      type: "newMessage",
      message: {
        senderName,
        receiverName,
        content,
        createdAt
      },
    })
  );
}

module.exports = initWebSocket;