/**
 * mercadolivre.js - Scraper para Mercado Livre
 * 
 * Monitora a página de Ofertas do Dia do Mercado Livre
 * e extrai: nome, preço, preço original, desconto, imagem e link.
 */

const { config } = require('../config');
const { scrapeWithRetry } = require('../utils/browser');

/**
 * Executa o scraping da página de ofertas do Mercado Livre
 * @returns {Array<Object>} Lista de ofertas extraídas
 */
async function scrapeMercadoLivre() {
  console.log('🤝 [Mercado Livre] Iniciando scraping...');

  const offers = await scrapeWithRetry(async (page) => {
    // Navegar para a página de ofertas
    await page.goto(config.urls.mercadolivre, {
      waitUntil: 'domcontentloaded',
      timeout: config.scraping.pageTimeout,
    });

    // Aguardar carregamento dos cards de produto
    await page.waitForSelector('.promotion-item, .poly-card, .andes-card, [class*="poly-card"], .deal-card', {
      timeout: 10000,
    }).catch(() => {
      console.log('   ⚠️ [Mercado Livre] Seletores primários não encontrados, tentando alternativas...');
    });

    // Scroll para carregar mais itens
    await autoScroll(page);

    // Extrair dados dos produtos
    const products = await page.evaluate((maxOffers) => {
      const items = [];

      // Seletores para cards do Mercado Livre
      const cardSelectors = [
        '.poly-card',
        '.promotion-item',
        '.andes-card',
        '[class*="poly-card"]',
        '.deal-card',
        '.ui-search-layout__item',
      ];

      let cards = [];
      for (const selector of cardSelectors) {
        cards = document.querySelectorAll(selector);
        if (cards.length > 0) break;
      }

      cards.forEach((card) => {
        if (items.length >= maxOffers) return;

        try {
          // Nome do produto
          const nameEl = card.querySelector(
            '.poly-component__title, .promotion-item__title, .ui-search-item__title, [class*="title"], h2, h3'
          );
          const name = nameEl ? nameEl.textContent.trim() : '';

          // Preço atual
          const priceEl = card.querySelector(
            '.poly-price__current .andes-money-amount, .andes-money-amount--cents-superscript, [class*="price"], .price-tag-fraction'
          );
          let price = '';
          if (priceEl) {
            // Mercado Livre separa reais e centavos em elementos diferentes
            const fractionEl = priceEl.querySelector('.andes-money-amount__fraction, .price-tag-fraction');
            const centsEl = priceEl.querySelector('.andes-money-amount__cents, .price-tag-cents');
            const currencyEl = priceEl.querySelector('.andes-money-amount__currency-symbol');

            if (fractionEl) {
              const currency = currencyEl ? currencyEl.textContent.trim() : 'R$';
              const fraction = fractionEl.textContent.trim();
              const cents = centsEl ? centsEl.textContent.trim() : '00';
              price = `${currency} ${fraction},${cents}`;
            } else {
              price = priceEl.textContent.trim();
            }
          }

          // Preço original
          const originalPriceEl = card.querySelector(
            '.andes-money-amount--previous, [class*="original-price"], s .andes-money-amount, .price-tag-deleted'
          );
          let originalPrice = '';
          if (originalPriceEl) {
            const origFraction = originalPriceEl.querySelector('.andes-money-amount__fraction, .price-tag-fraction');
            if (origFraction) {
              originalPrice = `R$ ${origFraction.textContent.trim()}`;
            } else {
              originalPrice = originalPriceEl.textContent.trim();
            }
          }

          // Desconto
          const discountEl = card.querySelector(
            '.poly-component__discount, [class*="discount"], .ui-search-price__second-line__label'
          );
          const discount = discountEl ? discountEl.textContent.trim() : '';

          // Imagem
          const imgEl = card.querySelector(
            'img[src*="http2.mlstatic"], img[data-src*="http2.mlstatic"], img[src*="meli"], img'
          );
          let image = '';
          if (imgEl) {
            image = imgEl.getAttribute('src') || imgEl.getAttribute('data-src') || '';
            // Garantir URL de imagem válida
            if (image && image.startsWith('data:')) {
              image = imgEl.getAttribute('data-src') || '';
            }
          }

          // Link do produto
          const linkEl = card.querySelector(
            'a[href*="mercadolivre.com.br"], a[href*="produto.mercadolivre"], a[href*="/MLB-"], a[href]'
          );
          let link = linkEl ? linkEl.getAttribute('href') : '';
          if (link && !link.startsWith('http')) {
            link = 'https://www.mercadolivre.com.br' + link;
          }

          // Cupom (ML ocasionalmente mostra cupons)
          const couponEl = card.querySelector(
            '[class*="coupon"], [class*="cupom"], [class*="highlight"]'
          );
          let coupon = null;
          if (couponEl) {
            const couponText = couponEl.textContent.trim();
            if (couponText.toLowerCase().includes('cupom') || couponText.toLowerCase().includes('off')) {
              coupon = couponText;
            }
          }

          // Frete grátis (informação extra útil)
          const freeShippingEl = card.querySelector(
            '[class*="free-shipping"], .poly-component__shipping, [class*="shipping"]'
          );
          const hasFreeShipping = freeShippingEl &&
            freeShippingEl.textContent.toLowerCase().includes('grátis');

          if (name && price && link) {
            const offer = {
              name,
              price,
              originalPrice: originalPrice || null,
              discount: discount || null,
              image: image || null,
              link,
              coupon,
              store: 'mercadolivre',
            };

            // Adicionar info de frete grátis ao cupom/observação
            if (hasFreeShipping && !coupon) {
              offer.coupon = '🚚 Frete Grátis';
            } else if (hasFreeShipping && coupon) {
              offer.coupon += ' | 🚚 Frete Grátis';
            }

            items.push(offer);
          }
        } catch (e) {
          // Ignorar cards com erro
        }
      });

      return items;
    }, config.scraping.maxOffersPerSite);

    console.log(`   ✅ [Mercado Livre] ${products.length} ofertas extraídas.`);
    return products;

  }, 'Mercado Livre');

  return offers;
}

/**
 * Scroll automático
 */
async function autoScroll(page) {
  await page.evaluate(async () => {
    await new Promise((resolve) => {
      let totalHeight = 0;
      const distance = 400;
      const timer = setInterval(() => {
        window.scrollBy(0, distance);
        totalHeight += distance;
        if (totalHeight >= 3000) {
          clearInterval(timer);
          resolve();
        }
      }, 200);
    });
  });
  await new Promise((resolve) => setTimeout(resolve, 2000));
}

module.exports = { scrapeMercadoLivre };