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

function Square(props) {
    return (
        <button className="square" onClick={props.onClick} >
            {props.value}
        </button>
    );
}

class Board extends React.Component {
    renderSquare(i) {
        return (
            <Square
                value={this.props.squares[i]}
                onClick={() => this.props.onClick(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,
        };
    }

    handleClick(i) {
        const history = this.state.history;
        const current = history[history.length - 1];
        const squares = current.squares.slice();
        if (calculateWinner(squares) || squares[i]) {
            return;
        }
        squares[i] = (this.state.xIsNext ? 'X' : 'O');
        this.setState({
            history: history.concat([{
                squares: squares,
            }]),
            xIsNext: !this.state.xIsNext,
        });
    }

    render() {
        const history = this.state.history;
        const current = history[history.length - 1];
        const winner = calculateWinner(current.squares);
        let status;
        if (winner) {
            status = 'Winner: ' + winner;
        } else {
            status = 'Next: ' + (this.state.xIsNext ? 'X' : 'O');
        }

        return (
            <div className="game">
                <div className="game-board">
                    <Board
                        squares={current.squares}
                        onClick={(i) => this.handleClick(i)}
                    />
                </div>
                <div className="game-info">
                    <div>{status}</div>
                    <ol>{/* TODO */}</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;
}

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

const root = ReactDOM.createRoot(document.getElementById("root"));
root.render(<Game />);