'use strict';

// Lista completa con país y siglas según ISO 3166-1 alpha-2
const countryList = [
  { name: "España", code: "ES" }, { name: "Francia", code: "FR" }, { name: "Alemania", code: "DE" }, { name: "Italia", code: "IT" },
  { name: "Portugal", code: "PT" }, { name: "Reino Unido", code: "GB" }, { name: "Estados Unidos", code: "US" }, { name: "Canadá", code: "CA" },
  { name: "México", code: "MX" }, { name: "Brasil", code: "BR" }, { name: "Argentina", code: "AR" }, { name: "Chile", code: "CL" },
  { name: "Japón", code: "JP" }, { name: "China", code: "CN" }, { name: "Australia", code: "AU" }, { name: "Rusia", code: "RU" },
  { name: "Sudáfrica", code: "ZA" }, { name: "Nueva Zelanda", code: "NZ" }, { name: "India", code: "IN" }, { name: "Egipto", code: "EG" },
  { name: "Grecia", code: "GR" }, { name: "Turquía", code: "TR" }, { name: "Ucrania", code: "UA" }, { name: "Suecia", code: "SE" },
  { name: "Noruega", code: "NO" }, { name: "Dinamarca", code: "DK" }, { name: "Finlandia", code: "FI" }, { name: "Irlanda", code: "IE" },
  { name: "Bélgica", code: "BE" }, { name: "Polonia", code: "PL" }, { name: "Suiza", code: "CH" }, { name: "Países Bajos", code: "NL" }
];

function getFlagEmoji(code) {
  // Las banderas se generan a partir de letras usando unicode, no por siglas textuales
  // Solo funcionan para países con código alpha-2 y script latino
  if (!code || code.length !== 2) return '';
  return String.fromCodePoint(
    ...code.toUpperCase().split('').map(c => 0x1F1E6 + c.charCodeAt(0) - 65)
  );
}

// Elegir N países aleatorios distintos con bandera, sin mutar la lista original
function pickRandomCountries(list, n) {
  const pool = list.slice(); // copia de seguridad
  const chosen = [];
  const used = new Set();
  while (chosen.length < n && pool.length > 0) {
    const idx = Math.floor(Math.random() * pool.length);
    const c = pool[idx];
    const flag = getFlagEmoji(c.code);
    if (flag && !used.has(c.code)) {
      chosen.push({ name: c.name, code: c.code, flag });
      used.add(c.code);
    }
    // Eliminar del pool para evitar repetir
    pool.splice(idx, 1);
  }
  return chosen;
}

// Referencias DOM
const flagsDiv = document.getElementById('flags');
const countriesDiv = document.getElementById('countries');
const statusDiv = document.getElementById('status');
const scoreSpan = document.getElementById('score-value');
const scoreTotal = document.getElementById('score-total');
const restartBtn = document.getElementById('restart-btn');
const pairsSelect = document.getElementById('pairs-count');

// Estado
let pairs = [];
let flags = [];
let countries = [];
let selectedFlag = null;
let selectedCountry = null;
let score = 0;
let totalPairs = 12;

// Utilidades
function shuffle(arr) {
  for (let i = arr.length - 1; i > 0; i--) {
    const j = Math.floor(Math.random() * (i + 1));
    [arr[i], arr[j]] = [arr[j], arr[i]];
  }
}
function setStatus(msg) {
  statusDiv.textContent = msg;
}

// Renderizado
function renderFlags() {
  // Limpieza segura
  flagsDiv.textContent = '';
  flags.forEach((p, i) => {
    const d = document.createElement('button');
    d.type = 'button';
    d.className = 'flag';
    d.textContent = p.flag; // seguro (caracter unicode)
    d.setAttribute('tabindex', '0');
    d.setAttribute('role', 'listitem');
    d.setAttribute('aria-label', `Bandera de ${p.name}`);
    d.setAttribute('aria-disabled', p.matched ? 'true' : 'false');
    d.setAttribute('aria-selected', selectedFlag === i ? 'true' : 'false');

    if (p.matched) d.classList.add('matched');
    if (selectedFlag === i) d.classList.add('selected');

    d.addEventListener('click', () => selectFlag(i));
    d.addEventListener('keydown', (e) => {
      if (e.key === 'Enter' || e.key === ' ') {
        e.preventDefault();
        selectFlag(i);
      }
    });

    flagsDiv.appendChild(d);
  });
}

function renderCountries() {
  countriesDiv.textContent = '';
  countries.forEach((p, i) => {
    const d = document.createElement('button');
    d.type = 'button';
    d.className = 'country';
    d.textContent = p.name; // seguro
    d.setAttribute('tabindex', '0');
    d.setAttribute('role', 'listitem');
    d.setAttribute('aria-label', `País ${p.name}`);
    d.setAttribute('aria-disabled', p.matched ? 'true' : 'false');
    d.setAttribute('aria-selected', selectedCountry === i ? 'true' : 'false');

    if (p.matched) d.classList.add('matched');
    if (selectedCountry === i) d.classList.add('selected');

    d.addEventListener('click', () => selectCountry(i));
    d.addEventListener('keydown', (e) => {
      if (e.key === 'Enter' || e.key === ' ') {
        e.preventDefault();
        selectCountry(i);
      }
    });

    countriesDiv.appendChild(d);
  });
}

// Lógica selección
function selectFlag(i) {
  if (flags[i].matched) return;
  selectedFlag = i;
  renderFlags();
  if (selectedCountry !== null) checkMatch();
}

function selectCountry(i) {
  if (countries[i].matched) return;
  selectedCountry = i;
  renderCountries();
  if (selectedFlag !== null) checkMatch();
}

function checkMatch() {
  if (selectedFlag === null || selectedCountry === null) return;

  const flagObj = flags[selectedFlag];
  const countryObj = countries[selectedCountry];

  if (!flagObj || !countryObj) return;

  if (flagObj.code === countryObj.code) {
    flags[selectedFlag].matched = true;
    countries[selectedCountry].matched = true;
    score++;
    scoreSpan.textContent = String(score);
    setStatus('¡Correcto!');
    renderFlags();
    renderCountries();
    if (score === pairs.length) {
      setStatus('¡Has emparejado todas las banderas! 🎉');
    }
  } else {
    setStatus('No es correcto, intenta otra vez.');
    // Reset de selección tras breve pausa
    setTimeout(() => {
      setStatus('');
      selectedFlag = null;
      selectedCountry = null;
      renderFlags();
      renderCountries();
    }, 850);
    return;
  }

  // Reset selección tras acierto
  selectedFlag = null;
  selectedCountry = null;
}

// Inicio/reinicio
function startGame() {
  // Leer número de parejas desde selector, con límites
  const desired = pairsSelect && Number(pairsSelect.value) ? Number(pairsSelect.value) : 12;
  totalPairs = Math.max(4, Math.min(desired, countryList.length));

  const fullList = countryList.slice(); // copia
  pairs = pickRandomCountries(fullList, totalPairs);
  // Si no se pudieron escoger las deseadas (por restricciones), ajustar total
  if (pairs.length < totalPairs) {
    totalPairs = pairs.length;
  }

  flags = pairs.map(o => ({ ...o }));
  countries = pairs.map(o => ({ ...o }));

  shuffle(flags);
  shuffle(countries);

  score = 0;
  scoreSpan.textContent = String(score);
  scoreTotal.textContent = String(pairs.length);
  selectedFlag = null;
  selectedCountry = null;

  renderFlags();
  renderCountries();
  setStatus('Empareja todas las banderas con su país');

  // Enfocar primera bandera para accesibilidad
  const firstFlag = flagsDiv.querySelector('.flag');
  if (firstFlag) firstFlag.focus();
}

// Listeners (evitar handlers inline)
restartBtn.addEventListener('click', startGame);
if (pairsSelect) {
  pairsSelect.addEventListener('change', startGame);
}

// Init
startGame();