const express = require('express');
const mysql = require('mysql');
const bodyParser = require('body-parser');
const cors = require('cors');
const path = require('path');
const app = express();
const port = 4040;

app.use(bodyParser.json());
app.use(cors());

// 创建 MySQL 连接
const db = mysql.createConnection({
  host: '172.17.0.1',
  user: 'login_test',
  password: 'tTiwnNbzMeLFxbLj',
  database: 'login_test'
});

db.connect(err => {
  if (err) {
    console.error('无法连接到数据库:', err);
    return;
  }
  console.log('已连接到数据库');
});

// 处理注册请求
app.post('/api/register', (req, res) => {
  const { username, password } = req.body;

  // 检查用户名和密码是否为空
  if (!username || !password) {
    return res.json({ success: false, message: '用户名和密码不能为空' });
  }

  const checkUserSql = 'SELECT * FROM users WHERE username = ?';
  const registerSql = 'INSERT INTO users (username, password) VALUES (?, ?)';

  db.query(checkUserSql, [username], (err, results) => {
    if (err) {
      return res.json({ success: false, message: '数据库查询失败' });
    }
    if (results.length > 0) {
      return res.json({ success: false, message: '用户名已存在' });
    }

    db.query(registerSql, [username, password], (err, result) => {
      if (err) {
        return res.json({ success: false, message: '注册失败' });
      }
      res.json({ success: true, message: '注册成功' });
    });
  });
});

// 处理登录请求
app.post('/api/login', (req, res) => {
  const { username, password } = req.body;

  // 检查用户名和密码是否为空
  if (!username || !password) {
    return res.json({ success: false, message: '用户名和密码不能为空' });
  }

  const sql = 'SELECT * FROM users WHERE username = ? AND password = ?';
  db.query(sql, [username, password], (err, results) => {
    if (err || results.length === 0) {
      return res.json({ success: false, message: '登录失败' });
    }
    res.json({ success: true, message: '登录成功' });
  });
});

// 提供静态文件服务
app.use(express.static(path.join(__dirname, 'public')));

// 所有其他请求返回 index.html
app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

app.listen(port, () => {
  console.log(`服务器在 http://localhost:${port} 上运行`);
});