const express = require('express');
const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello World!');
});

app.listen(port, () => {
  console.log(`Server running at http://localhost:${port}`);
});

// 生成雙token的輔助函數(shù)
function generateTokens(userId, additionalData = {}) {
  const payload = { userId, ...additionalData };
  
  // 生成access_token，1小時(shí)過(guò)期
  const accessToken = jwt.sign(
    payload, 
    process.env.JWT_SECRET || "xxx-your-secret-key", 
    { expiresIn: "1h" }
  );
  
  // 生成refresh_token，7天過(guò)期
  const refreshToken = jwt.sign(
    payload, 
    process.env.JWT_REFRESH_SECRET || "xxx-your-refresh-secret-key", 
    { expiresIn: "7d" }
  );
  
  return { accessToken, refreshToken };
}

// 微信認(rèn)證中間件
async function wxLogin(code) {
  try {
    // 使用環(huán)境變量中的微信配置
    const appid = process.env.APP_ID || process.env.APP_ID;
    const secret = process.env.APP_SECRET || process.env.APP_SECRET;

    // 調(diào)用微信接口獲取openid和session_key
    const response = await axios.get('https://api.weixin.qq.com/sns/jscode2session', {
      params: {
        appid,
        secret,
        js_code: code,
        grant_type: 'authorization_code',
      },
    });

    const { openid, session_key, errcode, errmsg } = response.data;

    if (errcode) {
      throw new Error(`WeChat API error: ${errcode}, ${errmsg}`);
    }

    return { openid, session_key };
  } catch (error) {
    console.error('WeChat authentication error:', error);
    throw error;
  }
}

// User模型定義
User.init(
  {
    userName: {
      comment: "用戶名",
      type: DataTypes.STRING,
      allowNull: false,
      unique: true,
    },
    password: {
      comment: "密碼",
      type: DataTypes.STRING,
      allowNull: true, // 允許為空，因?yàn)槲⑿诺卿洸恍枰艽a
    },
    email: {
      comment: "郵箱",
      type: DataTypes.STRING,
      allowNull: true, // 允許為空，因?yàn)槲⑿诺卿浛赡軟](méi)有郵箱
    },
    openid: {
      comment: "微信openid",
      type: DataTypes.STRING,
      allowNull: true,
      unique: true,
    },
    img: {
      comment: "微信頭像URL",
      type: DataTypes.STRING,
      allowNull: true,
    },
    lastOnlineTime: {
      comment: "最后登陸時(shí)間",
      type: DataTypes.DATE,
      allowNull: true,
    },
    refreshToken: {
      comment: "刷新令牌",
      type: DataTypes.TEXT,
      allowNull: true,
    },
  },
  {
    sequelize,
    modelName: "User",
  }
);

// 傳統(tǒng)用戶名密碼登錄
async function login(req, res) {
  const { userName, password } = req.body;

  try {
    // 檢查用戶名是否存在
    const user = await User.findOne({ where: { userName } });
    if (!user) {
      return res.status(401).json({ msg: "Invalid userName or password" });
    }

    // 檢查密碼是否匹配
    const isPasswordMatch = await bcrypt.compare(password, user.password);
    if (!isPasswordMatch) {
      return res.status(401).json({ msg: "Invalid userName or password" });
    }

    // 更新用戶的最后在線時(shí)間
    user.lastOnlineTime = new Date();
    await user.save();

    // 生成雙token
    const { accessToken, refreshToken } = generateTokens(user.id);

    // 保存refresh_token到數(shù)據(jù)庫(kù)
    user.refreshToken = refreshToken;
    await user.save();

    // 返回包含雙token的響應(yīng)
    res.json({
      accessToken,
      refreshToken,
      account: user.userName,
      email: user.email,
      userId: user.id,
    });
  } catch (error) {
    console.log("?? ~ login ~ error:", error);
    res.status(500).json({ msg: "Failed to log in" });
  }
}

// 微信登錄
async function wxLoginHandler(req, res) {
  const { code } = req.body;
  
  if (!code) {
    return res.status(400).json({ msg: "WeChat code is required" });
  }

  try {
    // 獲取微信openid和session_key
    const { openid, session_key } = await wxLogin(code);
    
    if (!openid) {
      return res.status(400).json({ msg: "Failed to get WeChat openid" });
    }
    
    // 查找或創(chuàng)建用戶
    let user = await User.findOne({ where: { openid } });
    
    if (!user) {
      // 如果用戶不存在，創(chuàng)建新用戶
      user = await User.create({
        userName: `wx_user_${openid.substring(0, 8)}`, // 生成一個(gè)基于openid的用戶名
        openid,
        lastOnlineTime: new Date(),
      });
    } else {
      // 更新用戶的最后在線時(shí)間
      user.lastOnlineTime = new Date();
    }

    // 生成雙token，包含openid和session_key
    const { accessToken, refreshToken } = generateTokens(user.id, {
      openid,
      session_key,
    });

    // 保存refresh_token到數(shù)據(jù)庫(kù)
    user.refreshToken = refreshToken;
    await user.save();

    // 返回用戶信息和雙token
    res.json({
      accessToken,
      refreshToken,
      userId: user.id,
      userName: user.userName,
      img: user.img,
      openid,
    });
  } catch (error) {
    console.log("?? ~ wxLoginHandler ~ error:", error);
    res.status(500).json({ msg: "Failed to login with WeChat" });
  }
}

// 刷新token
async function refreshToken(req, res) {
  try {
    const user = req.userData; // 從中間件獲取用戶數(shù)據(jù)
    
    // 生成新的雙token
    const additionalData = {};
    if (req.user.openid) {
      additionalData.openid = req.user.openid;
      additionalData.session_key = req.user.session_key;
    }
    
    const { accessToken: newAccessToken, refreshToken: newRefreshToken } =
      generateTokens(user.id, additionalData);
    
    // 更新數(shù)據(jù)庫(kù)中的refresh_token
    user.refreshToken = newRefreshToken;
    await user.save();
    
    // 返回新的雙token
    res.json({
      accessToken: newAccessToken,
      refreshToken: newRefreshToken,
    });
  } catch (error) {
    console.log("?? ~ refreshToken ~ error:", error);
    res.status(500).json({ msg: "Failed to refresh token" });
  }
}

// 鑒權(quán)中間件 - 只驗(yàn)證access_token
function authMiddleware(req, res, next) {
  const authHeader = req.headers["authorization"];
  // 從 Authorization 頭部解析 token
  const token = authHeader && authHeader.split(" ")[1];

  if (!token) {
    return res.status(401).json({ 
      error: "Access token is required",
      code: "MISSING_TOKEN"
    });
  }

  // 驗(yàn)證 access_token
  jwt.verify(token, process.env.JWT_SECRET || "xxx-your-secret-key", (err, user) => {
    if (err) {
      if (err.name === 'TokenExpiredError') {
        return res.status(401).json({ 
          error: "Access token expired", 
          code: "TOKEN_EXPIRED"
        });
      }
      
      return res.status(403).json({ 
        error: "Invalid access token",
        code: "INVALID_TOKEN"
      });
    }

    // 將用戶信息存儲(chǔ)到請(qǐng)求對(duì)象中
    req.user = user;
    next();
  });
}

// 驗(yàn)證refresh_token的中間件
async function refreshTokenMiddleware(req, res, next) {
  const { refreshToken } = req.body;
  
  if (!refreshToken) {
    return res.status(401).json({ 
      error: "Refresh token is required",
      code: "MISSING_REFRESH_TOKEN"
    });
  }

  try {
    // 驗(yàn)證refresh_token
    const decoded = jwt.verify(
      refreshToken, 
      process.env.JWT_REFRESH_SECRET || "xxx-your-refresh-secret-key"
    );
    
    // 查找用戶
    const user = await User.findByPk(decoded.userId);
    if (!user) {
      return res.status(401).json({ 
        error: "User not found",
        code: "USER_NOT_FOUND"
      });
    }
    
    // 檢查數(shù)據(jù)庫(kù)中的refresh_token是否匹配
    if (user.refreshToken !== refreshToken) {
      return res.status(401).json({ 
        error: "Invalid refresh token",
        code: "INVALID_REFRESH_TOKEN"
      });
    }
    
    // 將用戶信息存儲(chǔ)到請(qǐng)求對(duì)象中
    req.user = decoded;
    req.userData = user;
    
    next();
  } catch (error) {
    if (error.name === 'TokenExpiredError') {
      return res.status(401).json({ 
        error: "Refresh token expired",
        code: "REFRESH_TOKEN_EXPIRED"
      });
    }
    
    return res.status(401).json({ 
      error: "Invalid refresh token",
      code: "INVALID_REFRESH_TOKEN"
    });
  }
}

// 不需要認(rèn)證的路由
// 注冊(cè)
router.post('/register', authController.register);
// 登錄
router.post('/login', authController.login);
// 微信登錄
router.post('/wx-login', authController.wxLoginHandler); 

// 使用refresh token中間件的路由
router.post('/refresh-token', refreshTokenMiddleware, authController.refreshToken);

// 需要認(rèn)證的路由
router.post('/logout', authMiddleware, authController.logout);
// 用戶信息 CRUD
router.get('/user-info', authMiddleware, authController.getUserInfo);
router.put('/user-info', authMiddleware, authController.updateUserInfo);