import React, { useState } from 'react'

function Square ({ value, onSquareClick }) {
  return (
    <button className="square" onClick={onSquareClick}>
      {value}
    </button>
  )
}

export function Board ({ xIsNext, squares, onPlay }) {
  function handleClick (i) {
    if (calculateWinner(squares) || squares[i]) {
      return
    }

    const nextSquares = squares.slice()

    if (xIsNext) {
      nextSquares[i] = 'X'
    } else {
      nextSquares[i] = 'O'
    }

    onPlay(nextSquares)
  }

  const winner = calculateWinner(squares)
  let status

  if (winner) {
    status = `Winner: ${ winner}`
  } else {
    status = `Next player: ${ xIsNext ? 'X' : 'O'}`
  }

  return (
    <>
      <div className="status">{status}</div>
      <div className="board-row">
        <Square value={squares[0]} onSquareClick={() => handleClick(0)} />
        <Square value={squares[1]} onSquareClick={() => handleClick(1)} />
        <Square value={squares[2]} onSquareClick={() => handleClick(2)} />
      </div>
      <div className="board-row">
        <Square value={squares[3]} onSquareClick={() => handleClick(3)} />
        <Square value={squares[4]} onSquareClick={() => handleClick(4)} />
        <Square value={squares[5]} onSquareClick={() => handleClick(5)} />
      </div>
      <div className="board-row">
        <Square value={squares[6]} onSquareClick={() => handleClick(6)} />
        <Square value={squares[7]} onSquareClick={() => handleClick(7)} />
        <Square value={squares[8]} onSquareClick={() => handleClick(8)} />
      </div>
    </>
  )
}

export default function Game () {
  const [history, setHistory] = useState([Array(9).fill(null)])
  const [currentMove, setCurrentMove] = useState(0)
  const xIsNext = currentMove % 2 === 0
  const currentSquares = history[currentMove]

  function handlePlay (nextSquares) {
    const nextHistory = [...history.slice(0, currentMove + 1), nextSquares]

    setHistory(nextHistory)
    setCurrentMove(nextHistory.length - 1)
  }

  function jumpTo (nextMove) {
    setCurrentMove(nextMove)
  }

  const moves = history.map((squares, move) => {
    let description

    if (move > 0) {
      description = `Go to move #${ move}`
    } else {
      description = 'Go to game start'
    }

    return (
      <li key={move}>
        <button onClick={() => jumpTo(move)}>{description}</button>
      </li>
    )
  })

  return (
    <div className="game">
      <div className="game-board">
        <Board xIsNext={xIsNext} squares={currentSquares} onPlay={handlePlay} />
      </div>
      <div className="game-info">
        <ol>{moves}</ol>
      </div>
    </div>
  )
}

export 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
}
