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

const Pieces = {
    WhitePawn: './white_pawn.png',
    WhiteRook: './white_rook.png',
    WhiteKnight: './white_knight.png',
    WhiteBishop: './white_bishop.png',
    WhiteQueen: './white_queen.png',
    WhiteKing: './white_king.png',

    BlackPawn: './black_pawn.png',
    BlackRook: './black_rook.png',
    BlackKnight: './black_knight.png',
    BlackBishop: './black_bishop.png',
    BlackQueen: './black_queen.png',
    BlackKing: './black_king.png',
};

function Square(props) {
  let bg = {
      backgroundImage: `url(${props.value})`,
      // backgroundColor: "lightblue",
  };
  if (props.value != null) {
    return (
      <button
        className="square"
        onClick={props.onClick}
        style={bg}
      >
      </button>
    );
  } else {
    return (
      <button
        className="square"
        onClick={props.onClick}
      ></button>
    );
  }
}

class Board extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      squares: this.reset(),
      xIsNext: true,
    };
    this.reset();
  }

  reset() {
    let whiteRow = [
        Pieces.WhiteRook,
        Pieces.WhiteKnight,
        Pieces.WhiteBishop,
        Pieces.WhiteQueen,
        Pieces.WhiteKing,
        Pieces.WhiteBishop,
        Pieces.WhiteKnight,
        Pieces.WhiteRook
    ];
    let blackRow = [
        Pieces.BlackRook,
        Pieces.BlackKnight,
        Pieces.BlackBishop,
        Pieces.BlackQueen,
        Pieces.BlackKing,
        Pieces.BlackBishop,
        Pieces.BlackKnight,
        Pieces.BlackRook
    ];
    let squares = whiteRow.slice();
    squares = squares.concat(Array(8).fill(Pieces.WhitePawn));
    squares = squares.concat(Array(32).fill(null));
    squares = squares.concat(Array(8).fill(Pieces.BlackPawn));
    squares = squares.concat(blackRow.slice());
    return squares;
  }

  handleClick(i) {
    const squares = this.state.squares.slice();
    if (calculateWinner(squares) || squares[i]) {
      return;
    }
    squares[i] = this.state.xIsNext ? 'Black' : 'White';
    this.setState({
      squares: squares,
      xIsNext: !this.state.xIsNext,
    });
  }

  renderSquare(i) {
    return (
      <Square
        value={this.state.squares[i]}
        onClick={() => this.handleClick(i)}
      />
    );
  }

  row(row) {
    let i = row * 8;
    return (
      <div className="board-row">
        {this.renderSquare(i)}
        {this.renderSquare(i + 1)}
        {this.renderSquare(i + 2)}
        {this.renderSquare(i + 3)}
        {this.renderSquare(i + 4)}
        {this.renderSquare(i + 5)}
        {this.renderSquare(i + 6)}
        {this.renderSquare(i + 7)}
      </div>
    );
  }

  render() {
    const winner = calculateWinner(this.state.squares);
    let status;
    if (winner) {
      status = 'Winner: ' + winner;
    } else {
      status = 'Next player: ' + (this.state.xIsNext ? 'Black' : 'White');
    }

    var texttext =
      <div>
        <div className="status">{status}</div>
        {this.row(0)}
        {this.row(1)}
        {this.row(2)}
        {this.row(3)}
        {this.row(4)}
        {this.row(5)}
        {this.row(6)}
        {this.row(7)}
      </div>
    ;

    return (
        texttext
    );
  }
}

class Game extends React.Component {
  render() {
    return (
      <div className="game">
        <div className="game-board">
          <Board />
        </div>
        <div className="game-info">
          <div>{/* status */}</div>
          <ol>{/* TODO */}</ol>
        </div>
      </div>
    );
  }
}

// ========================================

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

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;
}