const express = require('express');
const bcrypt = require('bcryptjs');
const jwt = require('jsonwebtoken');
const validator = require('validator');
const dbConnector = require('../utils/dbConnector');

const router = express.Router();
const JWT_SECRET = process.env.JWT_SECRET || 'your-secret-key';

/**
 * @swagger
 * /api/v1/auth/register:
 *   post:
 *     summary: 用户注册
 *     description: 创建一个新的用户账户
 *     tags:
 *       - 认证管理
 *     requestBody:
 *       required: true
 *       content:
 *         application/json:
 *           schema:
 *             type: object
 *             required:
 *               - username
 *               - password
 *               - phone
 *             properties:
 *               username:
 *                 type: string
 *                 example: "user123"
 *                 description: 用户名
 *               password:
 *                 type: string
 *                 example: "password123"
 *                 description: 密码（至少6位）
 *               phone:
 *                 type: string
 *                 example: "13800138000"
 *                 description: 手机号
 *               email:
 *                 type: string
 *                 example: "user@example.com"
 *                 description: 邮箱地址
 *               user_type:
 *                 type: string
 *                 example: "farmer"
 *                 description: 用户类型
 *     responses:
 *       201:
 *         description: 注册成功
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 code:
 *                   type: integer
 *                   example: 201
 *                 message:
 *                   type: string
 *                   example: 注册成功
 *                 data:
 *                   type: object
 *                   properties:
 *                     user_id:
 *                       type: integer
 *                       example: 1
 *                     username:
 *                       type: string
 *                       example: "user123"
 *                     phone:
 *                       type: string
 *                       example: "13800138000"
 *                     email:
 *                       type: string
 *                       example: "user@example.com"
 *                     user_type:
 *                       type: string
 *                       example: "farmer"
 *                     token:
 *                       type: string
 *                       example: "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
 *       400:
 *         description: 请求参数错误
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 code:
 *                   type: integer
 *                   example: 400
 *                 message:
 *                   type: string
 *                   example: 用户名、密码和手机号为必填项
 *       409:
 *         description: 用户已存在
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 code:
 *                   type: integer
 *                   example: 409
 *                 message:
 *                   type: string
 *                   example: 用户名、手机号或邮箱已存在
 *
 * 用户注册
 */
router.post('/register', async (req, res, next) => {
  try {
    const { username, password, phone, email, user_type = 'farmer' } = req.body;

    // 参数验证
    if (!username || !password || !phone) {
      return res.status(400).json({
        code: 400,
        message: '用户名、密码和手机号为必填项',
        data: null
      });
    }

    if (password.length < 6) {
      return res.status(400).json({
        code: 400,
        message: '密码长度不能少于6位',
        data: null
      });
    }

    if (!validator.isMobilePhone(phone, 'zh-CN')) {
      return res.status(400).json({
        code: 400,
        message: '手机号格式不正确',
        data: null
      });
    }

    if (email && !validator.isEmail(email)) {
      return res.status(400).json({
        code: 400,
        message: '邮箱格式不正确',
        data: null
      });
    }

    // 检查用户是否已存在
    const existingUser = await dbConnector.query(
      'SELECT id FROM users WHERE username = ? OR phone = ? OR email = ?',
      [username, phone, email]
    );

    if (existingUser.length > 0) {
      return res.status(409).json({
        code: 409,
        message: '用户名、手机号或邮箱已存在',
        data: null
      });
    }

    // 加密密码
    const hashedPassword = await bcrypt.hash(password, 12);

    // 创建用户
    const result = await dbConnector.query(
      'INSERT INTO users (username, password, phone, email, user_type) VALUES (?, ?, ?, ?, ?)',
      [username, hashedPassword, phone, email, user_type]
    );

    // 生成JWT token
    const token = jwt.sign(
      { userId: result.insertId, username, user_type },
      JWT_SECRET,
      { expiresIn: '7d' }
    );

    res.status(201).json({
      code: 201,
      message: '注册成功',
      data: {
        user_id: result.insertId,
        username,
        phone,
        email,
        user_type,
        token
      }
    });

  } catch (error) {
    next(error);
  }
});

/**
 * @swagger
 * /api/v1/auth/login:
 *   post:
 *     summary: 用户登录
 *     description: 使用用户名和密码进行身份验证并获取访问令牌
 *     tags:
 *       - 认证管理
 *     requestBody:
 *       required: true
 *       content:
 *         application/json:
 *           schema:
 *             type: object
 *             required:
 *               - username
 *               - password
 *             properties:
 *               username:
 *                 type: string
 *                 example: "user123"
 *                 description: 用户名
 *               password:
 *                 type: string
 *                 example: "password123"
 *                 description: 密码
 *     responses:
 *       200:
 *         description: 登录成功
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 code:
 *                   type: integer
 *                   example: 200
 *                 message:
 *                   type: string
 *                   example: 登录成功
 *                 data:
 *                   type: object
 *                   properties:
 *                     user_id:
 *                       type: integer
 *                       example: 1
 *                     username:
 *                       type: string
 *                       example: "user123"
 *                     user_type:
 *                       type: string
 *                       example: "farmer"
 *                     token:
 *                       type: string
 *                       example: "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."
 *       400:
 *         description: 请求参数错误
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 code:
 *                   type: integer
 *                   example: 400
 *                 message:
 *                   type: string
 *                   example: 用户名和密码为必填项
 *       401:
 *         description: 用户名或密码错误
 *         content:
 *           application/json:
 *             schema:
 *               type: object
 *               properties:
 *                 code:
 *                   type: integer
 *                   example: 401
 *                 message:
 *                   type: string
 *                   example: 用户名或密码错误
 *
 * 用户登录
 */
router.post('/login', async (req, res, next) => {
  try {
    const { login, password } = req.body;

    if (!login || !password) {
      return res.status(400).json({
        code: 400,
        message: '登录账号和密码为必填项',
        data: null
      });
    }

    // 查询用户（支持用户名、手机号、邮箱登录）
    const user = await dbConnector.query(
      'SELECT * FROM users WHERE (username = ? OR phone = ? OR email = ?) AND status = 1',
      [login, login, login]
    );

    if (user.length === 0) {
      return res.status(401).json({
        code: 401,
        message: '用户不存在或已被禁用',
        data: null
      });
    }

    const userData = user[0];

    // 验证密码
    const isValidPassword = await bcrypt.compare(password, userData.password_hash);
    if (!isValidPassword) {
      return res.status(401).json({
        code: 401,
        message: '密码不正确',
        data: null
      });
    }

    // 更新最后登录时间
    await dbConnector.query(
      'UPDATE users SET last_login = CURRENT_TIMESTAMP WHERE id = ?',
      [userData.id]
    );

    // 生成JWT token
    const token = jwt.sign(
      { userId: userData.id, username: userData.username, user_type: userData.user_type },
      JWT_SECRET,
      { expiresIn: '7d' }
    );

    res.json({
      code: 200,
      message: '登录成功',
      data: {
        user_id: userData.id,
        username: userData.username,
        phone: userData.phone,
        email: userData.email,
        user_type: userData.user_type,
        avatar_url: userData.avatar_url,
        token
      }
    });

  } catch (error) {
    next(error);
  }
});

/**
 * 获取当前用户信息
 */
router.get('/me', async (req, res, next) => {
  try {
    // 从token中获取用户ID
    const token = req.headers.authorization?.replace('Bearer ', '');
    if (!token) {
      return res.status(401).json({
        code: 401,
        message: '未提供认证token',
        data: null
      });
    }

    const decoded = jwt.verify(token, JWT_SECRET);
    const user = await dbConnector.query(
      'SELECT id, username, phone, email, user_type, avatar_url, created_at, last_login FROM users WHERE id = ? AND status = 1',
      [decoded.userId]
    );

    if (user.length === 0) {
      return res.status(404).json({
        code: 404,
        message: '用户不存在',
        data: null
      });
    }

    res.json({
      code: 200,
      message: '获取成功',
      data: user[0]
    });

  } catch (error) {
    if (error.name === 'JsonWebTokenError') {
      return res.status(401).json({
        code: 401,
        message: '无效的token',
        data: null
      });
    }
    next(error);
  }
});

module.exports = router;