/**
 *  Web唐明明
 *  匆匆数载恍如梦，岁月迢迢华发增。
 *  碌碌无为枉半生，一朝惊醒万事空。
 *  ComponentName: '官方demo - 组件之间的传参'
 */

import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';

// 类组件
// class Square extends React.Component {
//   // 入口函数
//   render() {
//     return (
//       <button
//         className="square"
//         onClick={() => this.props.onSquare()}
//       >
//         {this.props.value}
//       </button>
//     );
//   }
// }

// 函数组件
const Square = (props) => {
  return (
    <button
      className="square"
      onClick={props.onSquare}
    >
      {props.value}
    </button>
  )
}

class Board extends React.Component {
  // 小方格方法
  renderSquare(i) {
    return <Square
      value={this.props.squares[i]}
      onSquare={()=>this.props.onBoard(i)}
    />;
  }
  render() {
    return (
      <div>
        <div className="board-row">
          {this.renderSquare(0)}
          {this.renderSquare(1)}
          {this.renderSquare(2)}
        </div>
        <div className="board-row">
          {this.renderSquare(3)}
          {this.renderSquare(4)}
          {this.renderSquare(5)}
        </div>
        <div className="board-row">
          {this.renderSquare(6)}
          {this.renderSquare(7)}
          {this.renderSquare(8)}
        </div>
      </div>
    );
  }
}

class Game extends React.Component {
  constructor (props) {
    super(props)
    this.state = {
      history: [{
        squares: Array(9).fill(null)
      }],
      xIsNext: true,
      stepIndex: 0
    }
  }
  // 定一个一个组件方法
  handleClick(i) {
    const history = this.state.history.slice(0, this.state.stepIndex + 1)
    const current = history[history.length - 1]
    const squares = current.squares.slice()
    if(calculateWinner(squares) || squares[i]){
      return
    }
    squares[i] = this.state.xInNext ? 'X': 'O'
    this.setState({
      history: history.concat([{ squares }]),
      xInNext: !this.state.xInNext,
      stepIndex: history.length
    })
    // Array.slice()返回数组选定的元素,相当于克隆了原有数组
  }
  jumpTo(index){
    this.setState({
      stepIndex: index,
      xIsNext: (index % 2) === 0,
    })
  }
  render() {
    const history = this.state.history
    const current = history[this.state.stepIndex]
    const winner = calculateWinner(current.squares)
    const moves = history.map((stepArr, index) => {
      const desc = index ? '下一步' + index : '开始游戏'
      return(
        <li key={index}>
          <button onClick={()=> this.jumpTo(index)}>{desc}</button>
        </li>
      )
    })
    let status;
    if(winner){
      status = '恭喜选手' + winner + '获胜~'
    }else{
      status = '下一位选手: ' + (this.state.xInNext ? 'X': 'O');
    }
    return (
      <div className="game">
        <div className="game-board">
          <Board
            squares={current.squares}
            onBoard={(i) => this.handleClick(i)}
          />
        </div>
        <div className="game-info">
          <div>{status}</div>
          <ol>{moves}</ol>
        </div>
      </div>
    );
  }
}

function calculateWinner(squares) {
  const lines = [
    [0, 1, 2],
    [3, 4, 5],
    [6, 7, 8],
    [0, 3, 6],
    [1, 4, 7],
    [2, 5, 8],
    [0, 4, 8],
    [2, 4, 6],
  ];
  for (let i = 0; i < lines.length; i++) {
    const [a, b, c] = lines[i];
    if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
      return squares[a];
    }
  }
  return null;
}

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