import {
  LayoutItem,
  normalizeLayoutPayload,
  parseMetadata,
  resolveIsActive,
} from '@/lib/layoutConfig';
import {
  DEFAULT_FAQ_PAGE,
  FaqCategory,
  FaqItem,
  FaqPageData,
  slugifyFaq,
} from '@/lib/faqDefaults';

export const FAQ_REGIONS = ['faq_hero', 'faq_categories'] as const;
export type FaqRegion = (typeof FAQ_REGIONS)[number];

function asFaqItem(raw: unknown): FaqItem | null {
  if (!raw || typeof raw !== 'object') return null;
  const o = raw as Record<string, unknown>;
  const question = String(o.question || o.title || o.q || '').trim();
  const answer = String(o.answer || o.description || o.a || '').trim();
  if (!question) return null;
  return { question, answer };
}

function asFaqCategory(raw: unknown, index: number): FaqCategory | null {
  if (!raw || typeof raw !== 'object') return null;
  const o = raw as Record<string, unknown>;
  const title = String(o.title || o.name || o.label || '').trim();
  const faqs = Array.isArray(o.faqs)
    ? o.faqs.map(asFaqItem).filter((x): x is FaqItem => Boolean(x))
    : [];
  if (!title && faqs.length === 0) return null;
  const slug = slugifyFaq(String(o.slug || o.id || title || `category-${index + 1}`));
  return {
    slug: slug || `category-${index + 1}`,
    title: title || 'FAQs',
    description: String(o.description || o.subtitle || '').trim() || undefined,
    faqs,
  };
}

export function normalizeFaqLayout(raw: unknown): LayoutItem[] {
  return normalizeLayoutPayload(raw)
    .map((item) => ({
      ...item,
      metadata: parseMetadata(item),
      metadata_json: parseMetadata(item),
    }))
    .sort(
      (a, b) =>
        (Number(a.display_order) || 0) - (Number(b.display_order) || 0)
    );
}

export function findFaqSection(
  layout: LayoutItem[],
  region: FaqRegion
): LayoutItem | null {
  return (
    layout.find((s) => {
      const key = parseMetadata(s).section_key || s.region || s.type || '';
      return key === region || s.region === region || s.type === region;
    }) || null
  );
}

export function parseFaqPageData(raw: unknown): FaqPageData {
  const layout = normalizeFaqLayout(raw);
  const hero = findFaqSection(layout, 'faq_hero');
  const cats = findFaqSection(layout, 'faq_categories');

  const heroVisible = !hero || resolveIsActive(hero);
  const catsVisible = !cats || resolveIsActive(cats);

  const heroMeta = parseMetadata(hero);
  const catsMeta = parseMetadata(cats);

  const title =
    (heroVisible && (hero?.title || heroMeta.title)) || DEFAULT_FAQ_PAGE.title;
  const subtitle =
    (heroVisible && (hero?.subtitle || heroMeta.subtitle)) ||
    DEFAULT_FAQ_PAGE.subtitle;

  const fromCms = catsVisible
    ? (Array.isArray(catsMeta.categories) ? catsMeta.categories : [])
        .map(asFaqCategory)
        .filter((x): x is FaqCategory => Boolean(x))
    : [];

  const categories =
    fromCms.length > 0
      ? fromCms.map((c) => ({
          ...c,
          faqs: c.faqs.length > 0 ? c.faqs : [],
        }))
      : DEFAULT_FAQ_PAGE.categories;

  return {
    title: String(title).trim() || DEFAULT_FAQ_PAGE.title,
    subtitle: String(subtitle).trim() || DEFAULT_FAQ_PAGE.subtitle,
    categories:
      categories.filter((c) => c.faqs.length > 0 || c.title).length > 0
        ? categories
        : DEFAULT_FAQ_PAGE.categories,
  };
}