const express = require('express');
const app = express();
app.use(express.json());

// 模拟数据库
let users = [
  { id: 1, name: 'John Doe', email: 'john@example.com' },
  { id: 2, name: 'Jane Smith', email: 'jane@example.com' }
];

// 获取所有用户
app.get('/users', (req, res) => {
  res.status(200).json(users);
});

// 获取单个用户
app.get('/users/:id', (req, res) => {
  const user = users.find(u => u.id === parseInt(req.params.id));
  if (!user) return res.status(404).json({ message: 'User not found' });
  res.json(user);
});

// 创建用户
app.post('/users', (req, res) => {
  const user = {
    id: users.length + 1,
    name: req.body.name,
    email: req.body.email
  };
  users.push(user);
  res.status(201).json(user);
});

// 更新用户
app.put('/users/:id', (req, res) => {
  const user = users.find(u => u.id === parseInt(req.params.id));
  if (!user) return res.status(404).json({ message: 'User not found' });

  user.name = req.body.name;
  user.email = req.body.email;
  res.json(user);
});

// 删除用户
app.delete('/users/:id', (req, res) => {
  const userIndex = users.findIndex(u => u.id === parseInt(req.params.id));
  if (userIndex === -1) return res.status(404).json({ message: 'User not found' });

  users.splice(userIndex, 1);
  res.status(204).send();
});

const PORT = 3000;
app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});