'use strict';

const boardDiv = document.getElementById('board');
const statusDiv = document.getElementById('status');
const restartBtn = document.getElementById('restart-btn');
const firstPlayerSelect = document.getElementById('first-player');
const scoreXSpan = document.getElementById('score-x');
const scoreOSpan = document.getElementById('score-o');
const scoreDrawSpan = document.getElementById('score-d');

const WIN_COMBOS = [
  [0, 1, 2], [3, 4, 5], [6, 7, 8], // Filas
  [0, 3, 6], [1, 4, 7], [2, 5, 8], // Columnas
  [0, 4, 8], [2, 4, 6]             // Diagonales
];

let board = Array(9).fill('');
let currentPlayer = 'X';
let gameOver = false;
let scores = { X: 0, O: 0, D: 0 };

function loadScores() {
  try {
    const raw = localStorage.getItem('ttt_scores');
    if (raw) {
      const parsed = JSON.parse(raw);
      if (parsed && typeof parsed === 'object') {
        scores.X = Number(parsed.X) || 0;
        scores.O = Number(parsed.O) || 0;
        scores.D = Number(parsed.D) || 0;
      }
    }
  } catch (_) {
    // Ignorar errores de parsing o acceso
  }
}

function saveScores() {
  try {
    localStorage.setItem('ttt_scores', JSON.stringify(scores));
  } catch (_) {
    // Ignorar errores de almacenamiento
  }
}

function updateScoreUI() {
  if (scoreXSpan) scoreXSpan.textContent = String(scores.X);
  if (scoreOSpan) scoreOSpan.textContent = String(scores.O);
  if (scoreDrawSpan) scoreDrawSpan.textContent = String(scores.D);
}

function initBoardDom() {
  // Crear la cuadrícula de 3x3 solo si no existe
  if (boardDiv.children.length === 9) {
    // limpiar estado de clases win previas
    Array.from(boardDiv.children).forEach(c => c.classList.remove('win'));
    return;
  }
  boardDiv.textContent = '';
  for (let idx = 0; idx < 9; idx++) {
    const cell = document.createElement('button');
    cell.type = 'button';
    cell.className = 'cell';
    cell.setAttribute('data-idx', String(idx));
    cell.setAttribute('aria-label', `Casilla ${idx + 1}`);
    cell.setAttribute('role', 'gridcell');
    cell.addEventListener('click', onCellClick);
    cell.addEventListener('keydown', (e) => {
      if (e.key === 'Enter' || e.key === ' ') onCellClick(e);
    });
    boardDiv.appendChild(cell);
  }
  boardDiv.setAttribute('aria-disabled', 'false');
}

function render() {
  for (let i = 0; i < 9; i++) {
    const cellEl = boardDiv.children[i];
    if (!cellEl) continue;
    cellEl.textContent = board[i];
  }
}

function setStatus(msg) {
  statusDiv.textContent = msg;
}

function checkWinner(player) {
  for (const combo of WIN_COMBOS) {
    const [a, b, c] = combo;
    if (board[a] === player && board[b] === player && board[c] === player) {
      return { win: true, combo };
    }
  }
  return { win: false, combo: null };
}

function highlightCombo(combo) {
  if (!combo) return;
  combo.forEach(i => {
    const el = boardDiv.children[i];
    if (el) el.classList.add('win');
  });
}

function endGame(result, combo) {
  gameOver = true;
  boardDiv.setAttribute('aria-disabled', 'true');

  if (result === 'X' || result === 'O') {
    setStatus(`¡${result} gana! 🎉`);
    scores[result] += 1;
    highlightCombo(combo);
  } else {
    setStatus('¡Empate!');
    scores.D += 1;
  }

  updateScoreUI();
  saveScores();
}

function onCellClick(e) {
  const target = e.currentTarget;
  const idx = Number(target.getAttribute('data-idx'));

  if (gameOver || !Number.isInteger(idx)) return;
  if (board[idx] !== '') return;

  board[idx] = currentPlayer;
  render();

  const { win, combo } = checkWinner(currentPlayer);
  if (win) {
    endGame(currentPlayer, combo);
    return;
  }

  // Comprueba empate
  if (board.every(cell => cell !== '')) {
    endGame('D', null);
    return;
  }

  // Cambiar turno
  currentPlayer = currentPlayer === 'X' ? 'O' : 'X';
  setStatus(`Turno de ${currentPlayer}`);
}

function startGame() {
  board = Array(9).fill('');
  gameOver = false;

  // Determinar primer jugador desde el selector si existe
  if (firstPlayerSelect && (firstPlayerSelect.value === 'X' || firstPlayerSelect.value === 'O')) {
    currentPlayer = firstPlayerSelect.value;
  } else {
    currentPlayer = 'X';
  }

  boardDiv.setAttribute('aria-disabled', 'false');
  initBoardDom();
  // Remover cualquier resaltado previo
  Array.from(boardDiv.children).forEach(c => c.classList.remove('win'));
  render();
  setStatus(`Turno de ${currentPlayer}`);
}

// Listeners
restartBtn.addEventListener('click', startGame);
if (firstPlayerSelect) {
  firstPlayerSelect.addEventListener('change', () => {
    // Solo afecta si la partida no ha empezado o si no ha terminado aún
    if (!gameOver && board.every(v => v === '')) {
      currentPlayer = firstPlayerSelect.value;
      setStatus(`Turno de ${currentPlayer}`);
    }
  });
}

// Init
loadScores();
updateScoreUI();
startGame();