import React, { Component } from 'react';
import { render } from 'react-dom';
import './style.css';


class Item extends Component {

  render() {
    const selectItem = this.props.items[this.props.selectIndex]
    console.log(selectItem);
    
    return ( 
      
        <li onClick={() => this.props.select(this.props.index)}>
          <div>
            Name:{this.props.item.name}
          </div>
        </li>
    )
  }
}

class ItemDetails extends Component {
 
  render() {
    const selectItem = this.props.items[this.props.selectIndex]
    console.log(selectItem);
    let content = this.props.items.map((item, index) => {
      return (
        <div className={this.props.selectIndex === index?'show':'hide'}>
          <p>
              Description:{item.description}
          </p>
          {item.stopWatch}
        </div>
      );
    })
    return (  
      <div>
        {selectItem ?
            content
          :
          null
        }
      </div>
    )
  }
}

class App extends React.Component {
  constructor() {
    super();

    this.state = {

      items: [
        {
          name: 'A',
          description: 'Hello',
          stopWatch: <Stopwatch key={1} />
        },
        {
          name: 'B',
          description: 'World',
          stopWatch: <Stopwatch key={2} />
        }
      ],
      selectIndex: null
    };
  }

  select = (index) => {
    this.setState({
      selectIndex: index
    })
  }


  render() {
    console.log(this.state.selectIndex)
    return (
      <div>
        <ul>
          {
            this.state.items
              .map((item, index) =>
                <Item
                  key={index}
                  index={index}
                  item={item}
                  select={this.select}
                  items = {this.state.items}
                  selectIndex = {this.state.selectIndex}
                />
              )
          }
        </ul>
         <ItemDetails
            items = {this.state.items}
            selectIndex = {this.state.selectIndex}

        />
      </div>
    );
  }
}


class Stopwatch extends Component {
  constructor() {
    super();

    this.state = {
      timerOn: false,
      timerStart: 0,
      timerTime: 0
    };
  }

  startTimer = () => {
    this.setState({
      timerOn: true,
      timerTime: this.state.timerTime,
      timerStart: Date.now() - this.state.timerTime
    });
    this.timer = setInterval(() => {
      this.setState({
        timerTime: Date.now() - this.state.timerStart
      });
    }, 10);
  };

  stopTimer = () => {
    this.setState({ timerOn: false });
    clearInterval(this.timer);
  };

  resetTimer = () => {
    this.setState({
      timerStart: 0,
      timerTime: 0
    });
  };

  render() {
      const { timerTime } = this.state;
      let centiseconds = ("0" + (Math.floor(timerTime / 10) % 100)).slice(-2);
      let seconds = ("0" + (Math.floor(timerTime / 1000) % 60)).slice(-2);
      let minutes = ("0" + (Math.floor(timerTime / 60000) % 60)).slice(-2);
      let hours = ("0" + Math.floor(timerTime / 3600000)).slice(-2);

    return (
      <div>
      

    <div className="Stopwatch-display">
      {hours} : {minutes} : {seconds} : {centiseconds}
    </div>


    {this.state.timerOn === false && this.state.timerTime === 0 && (
    <button onClick={this.startTimer}>Start</button>
    )}

    {this.state.timerOn === true && (
      <button onClick={this.stopTimer}>Stop</button>
    )}

    {this.state.timerOn === false && this.state.timerTime > 0 && (
      <button onClick={this.startTimer}>Resume</button>
    )}
    
    {this.state.timerOn === false && this.state.timerTime > 0 && (
      <button onClick={this.resetTimer}>Reset</button>
    )}
        </div>
      );
    }
}


render(<App />, document.getElementById('root'));

h1, p {
  font-family: Lato;
}

.show {
  display: block;
}

.hide {
  display: none;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="root"></div>