企业社交营销秒杀

import React, { useState, useEffect } from 'react';

function Countdown({ endTime }) {
  const [timeLeft, setTimeLeft] = useState(calculateTimeLeft(endTime));

  useEffect(() => {
    const timer = setTimeout(() => {
      setTimeLeft(calculateTimeLeft(endTime));
    }, 1000);

    return () => clearTimeout(timer);
  }, [endTime]);

  function calculateTimeLeft(endTime) {
    const difference = new Date(endTime).getTime() - new Date().getTime();
    if (difference <= 0) return { days: 0, hours: 0, minutes: 0, seconds: 0 };
    const days = Math.floor(difference / (1000 * 60 * 60 * 24));
    const hours = Math.floor((difference / (1000 * 60 * 60)) % 24);
    const minutes = Math.floor((difference / 1000 / 60) % 60);
    const seconds = Math.floor((difference / 1000) % 60);
    return { days, hours, minutes, seconds };
  }

  return (
    <div>
      {timeLeft.days}天 {timeLeft.hours}小时 {timeLeft.minutes}分 {timeLeft.seconds}秒
    </div>
  );
}

export default Countdown;

const express = require('express');
const app = express();
const bodyParser = require('body-parser');

app.use(bodyParser.json());

let stock = 100; // 初始库存

app.post('/seckill', (req, res) => {
  if (stock > 0) {
    stock--;
    res.json({ success: true, message: '秒杀成功' });
  } else {
    res.json({ success: false, message: '库存不足' });
  }
});

app.listen(3000, () => {
  console.log('Server is running on port 3000');
});