const asyncHandler = require('express-async-handler');
const User = require('../models/User');
const { generateToken } = require('../config/auth');
const logger = require('../utils/logger');

// @desc    用户注册
// @route   POST /api/auth/register
// @access  Public
const registerUser = asyncHandler(async (req, res) => {
  const { username, password } = req.body;

  // 检查用户是否已存在
  const userExists = await User.findOne({ username });

  if (userExists) {
    res.status(400);
    throw new Error('用户已存在');
  }

  // 创建用户
  const user = await User.create({
    username,
    password,
  });

  if (user) {
    res.status(201).json({
      _id: user._id,
      username: user.username,
      isAdmin: user.isAdmin,
      token: generateToken(user._id),
    });
  } else {
    res.status(400);
    throw new Error('无效的用户数据');
  }
});

// @desc    用户登录
// @route   POST /api/auth/login
// @access  Public
const loginUser = asyncHandler(async (req, res) => {
  const { username, password } = req.body;

  logger.info(`登录尝试: ${username}`);

  // 查找用户
  const user = await User.findOne({ username });
  
  if (!user) {
    logger.warn(`用户不存在: ${username}`);
    res.status(401);
    throw new Error('用户名或密码错误');
  }

  // 检查密码
  const isMatch = await user.matchPassword(password);
  logger.info(`密码匹配结果: ${isMatch}`);

  if (isMatch) {
    const token = generateToken(user._id);
    logger.info(`登录成功: ${username}`);
    
    res.json({
      _id: user._id,
      username: user.username,
      isAdmin: user.isAdmin,
      token: token,
    });
  } else {
    logger.warn(`密码不匹配: ${username}`);
    res.status(401);
    throw new Error('用户名或密码错误');
  }
});

// @desc    获取当前用户资料
// @route   GET /api/auth/profile
// @access  Private
const getUserProfile = asyncHandler(async (req, res) => {
  const user = await User.findById(req.user._id).select('-password');

  if (user) {
    res.json({
      _id: user._id,
      username: user.username,
      isAdmin: user.isAdmin,
    });
  } else {
    res.status(404);
    throw new Error('用户未找到');
  }
});

module.exports = {
  registerUser,
  loginUser,
  getUserProfile,
};