/** Safe for double-quoted HTML attributes */
const escAttr = (str) =>
  String(str ?? "")
    .replace(/&/g, "&")
    .replace(/"/g, """)
    .replace(/</g, "&lt;");

/**
 * Head tags for prerendered category URLs — explicit canonical per /Kategorie/{slug}
 * so Google does not cluster different listing pages (e.g. neu vs Seeds) as duplicates.
 */
const generateCategoryMetaTags = (category, baseUrl, config) => {
  const root = baseUrl.endsWith("/") ? baseUrl.slice(0, -1) : baseUrl;
  const categoryUrl = `${root}/Kategorie/${category.seoName}`;
  const name = category.name || `Kategorie ${category.seoName}`;
  const site = config.siteName || config.brandName;
  const desc = `${name} bei ${config.brandName}: Growshop-Sortiment online kaufen. Schnelle Lieferung, Laden Dresden.`;
  const descShort = desc.length > 160 ? `${desc.slice(0, 157)}...` : desc;
  const e = escAttr;
  const logoUrl =
    config.images && config.images.logo
      ? `${root}${config.images.logo}`
      : `${root}/assets/images/nopicture.jpg`;

  return `
    <meta name="description" content="${e(descShort)}">
    <meta property="og:title" content="${e(`${name} | ${site}`)}">
    <meta property="og:description" content="${e(descShort)}">
    <meta property="og:url" content="${categoryUrl}">
    <meta property="og:type" content="website">
    <meta property="og:image" content="${e(logoUrl)}">
    <meta property="og:site_name" content="${e(site)}">
    <meta name="twitter:card" content="summary_large_image">
    <meta name="twitter:title" content="${e(`${name} | ${site}`)}">
    <meta name="twitter:description" content="${e(descShort)}">
    <meta name="robots" content="index, follow">
    <link rel="canonical" href="${categoryUrl}">
  `;
};

const generateCategoryJsonLd = (category, products = [], baseUrl, config) => {
  // Category IDs to skip (seeds, plants, headshop items)
  const skipCategoryIds = [689, 706, 709, 711, 714, 748, 749, 896, 710, 924, 923, 922, 921, 916, 278, 259, 258];

  // Check if category ID is in skip list
  if (category.id && skipCategoryIds.includes(parseInt(category.id))) {
    return '';
  }

  const root = baseUrl.endsWith("/") ? baseUrl.slice(0, -1) : baseUrl;
  const categoryUrl = `${root}/Kategorie/${category.seoName}`;

  const id = {
    business: `${root}#business`,
    website: `${root}#website`,
    breadcrumb: `${categoryUrl}#breadcrumb`,
    itemList: `${categoryUrl}#itemlist`,
  };

  const logoUrl =
    config.images && config.images.logo
      ? `${root}${config.images.logo}`
      : undefined;

  const businessNode = {
    "@id": id.business,
    "@type": ["GardenStore", "LocalBusiness", "Organization"],
    name: config.brandName,
    url: root,
    ...(logoUrl && {
      logo: { "@type": "ImageObject", url: logoUrl },
      image: { "@type": "ImageObject", url: logoUrl },
    }),
  };

  const websiteNode = {
    "@id": id.website,
    "@type": "WebSite",
    name: config.siteName || config.brandName,
    url: root,
    publisher: { "@id": id.business },
  };

  const breadcrumbNode = {
    "@id": id.breadcrumb,
    "@type": "BreadcrumbList",
    itemListElement: [
      {
        "@type": "ListItem",
        position: 1,
        name: "Home",
        item: root,
      },
      {
        "@type": "ListItem",
        position: 2,
        name: category.name,
        item: categoryUrl,
      },
    ],
  };

  const collectionPageNode = {
    "@id": categoryUrl,
    "@type": "CollectionPage",
    name: category.name,
    url: categoryUrl,
    description: `${category.name} - Entdecken Sie unsere Auswahl an hochwertigen Produkten`,
    isPartOf: { "@id": id.website },
    breadcrumb: { "@id": id.breadcrumb },
  };

  const graph = [businessNode, websiteNode, breadcrumbNode, collectionPageNode];

  // ItemList: URLs only — full Product/Offer markup belongs on each /Artikel/… page (Google guidelines).
  const withUrls = (products || []).filter((p) => p && p.seoName);
  if (withUrls.length > 0) {
    collectionPageNode.mainEntity = { "@id": id.itemList };

    graph.push({
      "@id": id.itemList,
      "@type": "ItemList",
      numberOfItems: withUrls.length,
      itemListElement: withUrls.map((product, index) => ({
        "@type": "ListItem",
        position: index + 1,
        item: `${root}/Artikel/${product.seoName}`,
      })),
    });
  }

  const categoryGraph = {
    "@context": "https://schema.org",
    "@graph": graph,
  };

  return `<script type="application/ld+json">${JSON.stringify(
    categoryGraph
  )}</script>`;
};

module.exports = {
  generateCategoryMetaTags,
  generateCategoryJsonLd,
};