'use strict';

const DIFFICULTIES = {
  normal: { max: 100, attempts: 7 },
  facil: { max: 50, attempts: 10 },
  dificil: { max: 200, attempts: 7 },
  extremo: { max: 1000, attempts: 10 }
};

let randomNumber = 0;
let attemptsLeft = 0;
let attemptsTotal = 0;
let maxNumber = 100;
let history = [];
let currentDifficulty = 'normal';

// DOM refs
const guessInput = document.getElementById('guess-input');
const guessBtn = document.getElementById('guess-btn');
const restartBtn = document.getElementById('restart-btn');
const infoDiv = document.getElementById('info');
const attemptsSpan = document.getElementById('attempts-left');
const difficultySelect = document.getElementById('difficulty');
const errorDiv = document.getElementById('error');
const rangeMaxSpan = document.getElementById('range-max');
const attemptsTotalSpan = document.getElementById('attempts-total');
const bestScoreSpan = document.getElementById('best-score');
const historyList = document.getElementById('history-list');

function getBest(difficulty) {
  const key = `adivina_best_${difficulty}`;
  const v = localStorage.getItem(key);
  return v ? parseInt(v, 10) : null;
}

function setBest(difficulty, attemptsUsed) {
  const prev = getBest(difficulty);
  if (prev === null || attemptsUsed < prev) {
    localStorage.setItem(`adivina_best_${difficulty}`, String(attemptsUsed));
    bestScoreSpan.textContent = String(attemptsUsed);
  }
}

function updateBestDisplay() {
  const best = getBest(currentDifficulty);
  bestScoreSpan.textContent = best !== null ? String(best) : '—';
}

function renderHistory() {
  // Safe clear
  while (historyList.firstChild) historyList.removeChild(historyList.firstChild);
  history.forEach(item => {
    const li = document.createElement('li');
    li.textContent = `${item.guess} → ${item.hint}`;
    historyList.appendChild(li);
  });
}

function startGame() {
  currentDifficulty = (difficultySelect && difficultySelect.value) || 'normal';
  const conf = DIFFICULTIES[currentDifficulty] || DIFFICULTIES.normal;

  maxNumber = conf.max;
  attemptsTotal = conf.attempts;
  attemptsLeft = attemptsTotal;
  randomNumber = Math.floor(Math.random() * maxNumber) + 1;
  history = [];

  // Update UI
  if (rangeMaxSpan) rangeMaxSpan.textContent = String(maxNumber);
  if (attemptsTotalSpan) attemptsTotalSpan.textContent = String(attemptsTotal);
  attemptsSpan.textContent = String(attemptsLeft);
  errorDiv.textContent = '';
  infoDiv.textContent = '';
  renderHistory();
  updateBestDisplay();

  // Reset input/button state
  guessInput.value = '';
  guessInput.disabled = false;
  guessInput.setAttribute('min', '1');
  guessInput.setAttribute('max', String(maxNumber));
  guessBtn.disabled = false;
  restartBtn.classList.add('hidden');
  guessInput.focus();
}

function checkGuess() {
  errorDiv.textContent = '';

  const raw = guessInput.value.trim();
  if (raw === '') {
    errorDiv.textContent = 'Introduce un número.';
    return;
  }

  const guess = Number(raw);
  if (!Number.isFinite(guess) || !Number.isInteger(guess)) {
    errorDiv.textContent = 'El valor debe ser un número entero.';
    return;
  }
  if (guess < 1 || guess > maxNumber) {
    errorDiv.textContent = `El número debe estar entre 1 y ${maxNumber}.`;
    return;
  }

  attemptsLeft--;
  attemptsSpan.textContent = String(attemptsLeft);

  if (guess === randomNumber) {
    infoDiv.textContent = '¡Correcto! 🎉 Has adivinado el número.';
    const usedAttempts = attemptsTotal - attemptsLeft;
    history.push({ guess, hint: '✅ Correcto' });
    renderHistory();
    endGame(true, usedAttempts);
    return;
  }

  const hint = guess < randomNumber ? '⬇️ Bajo' : '⬆️ Alto';
  infoDiv.textContent = guess < randomNumber
    ? 'Demasiado bajo. Intenta nuevamente.'
    : 'Demasiado alto. Intenta nuevamente.';
  history.push({ guess, hint });
  renderHistory();

  if (attemptsLeft === 0) {
    infoDiv.textContent = `¡Oh no! Te quedaste sin intentos. El número era ${randomNumber}.`;
    endGame(false, attemptsTotal);
  }
}

function endGame(won, usedAttempts) {
  guessInput.disabled = true;
  guessBtn.disabled = true;
  restartBtn.classList.remove('hidden');

  if (won) {
    setBest(currentDifficulty, usedAttempts);
  }
}

// Listeners (avoid inline handlers)
guessBtn.addEventListener('click', checkGuess);
restartBtn.addEventListener('click', startGame);
guessInput.addEventListener('keydown', (e) => {
  if (e.key === 'Enter') checkGuess();
});
guessInput.addEventListener('input', () => {
  errorDiv.textContent = '';
});
if (difficultySelect) {
  difficultySelect.addEventListener('change', startGame);
}

// Init
startGame();