React: Pomodoro Clock:倒计时如何进行？

import React, { Component } from 'react';

class PomodoroClock extends Component {
  constructor(props) {
    super(props);
    this.state = {
      time: 25 * 60, // 初始时间为25分钟，以秒为单位
      isRunning: false, // 计时器是否正在运行
    };
  }

  componentDidMount() {
    // 启动计时器
    this.startTimer();
  }

  startTimer() {
    this.timer = setInterval(() => {
      this.setState(prevState => ({
        time: prevState.time - 1,
      }));
    }, 1000);
  }

  pauseTimer() {
    clearInterval(this.timer);
  }

  resetTimer() {
    this.setState({
      time: 25 * 60,
    });
  }

  formatTime() {
    const { time } = this.state;
    const minutes = Math.floor(time / 60);
    const seconds = time % 60;
    return `${minutes.toString().padStart(2, '0')}:${seconds.toString().padStart(2, '0')}`;
  }

  render() {
    const { time, isRunning } = this.state;
    return (
      <div>
        <div>{this.formatTime()}</div>
        <button onClick={() => this.pauseTimer()}>暂停</button>
        <button onClick={() => this.resetTimer()}>重置</button>
      </div>
    );
  }
}

export default PomodoroClock;