import type { MetadataRoute } from 'next';
import {
  getBlogSitemapEntries,
  getCategorySitemapEntries,
  getProductSitemapEntries,
} from 'brainerce';
import { getServerClient } from '@/core/lib/brainerce.server';
import { getCanonicalSiteUrl } from '@/core/lib/site-url';

/**
 * Storefront sitemap: static pages + every published product, category,
 * blog post, and merchant-authored content page.
 *
 * Products MUST go through `getProductSitemapEntries` — the public listing
 * API clamps `limit` to 100, so a naive `getProducts({ limit: 1000 })` call
 * silently truncates the sitemap for any store with more than 100 products.
 * The helper uses a dedicated lightweight endpoint with a 5000-product cap.
 */
export default async function sitemap(): Promise<MetadataRoute.Sitemap> {
  const baseUrl = await getCanonicalSiteUrl();

  const client = await getServerClient();
  const storeInfo = await client.getStoreInfo().catch(() => null);
  const supportedLocales = storeInfo?.i18n?.supportedLocales ?? [];
  const defaultLoc = storeInfo?.i18n?.defaultLocale ?? storeInfo?.language ?? '';
  const isMultiLocale = supportedLocales.length > 1;
  const locales = isMultiLocale ? supportedLocales : undefined;

  // Indexable static routes. Cart/checkout/account/login are noindex — never
  // list them here.
  const staticPaths: Array<{ path: string; priority: number }> = [
    { path: '/', priority: 1 },
    { path: '/products', priority: 0.9 },
    { path: '/faq', priority: 0.5 },
    { path: '/contact', priority: 0.5 },
  ];
  const staticPages: MetadataRoute.Sitemap = (isMultiLocale ? supportedLocales : ['']).flatMap(
    (loc) => {
      const prefix = !isMultiLocale || loc === defaultLoc ? '' : `/${loc}`;
      return staticPaths.map(({ path, priority }) => ({
        url: `${baseUrl}${prefix}${path === '/' ? (prefix ? '' : '/') : path}`,
        lastModified: new Date(),
        priority,
      }));
    }
  );

  // Each section fails independently to an empty list — a transient API error
  // on one content type must not blank the whole sitemap.
  const [productPages, categoryPages, blogPages, contentPages] = await Promise.all([
    getProductSitemapEntries(client, {
      siteUrl: baseUrl,
      locales,
      defaultLocale: defaultLoc,
    }).catch(() => []),
    // Category (collection) pages — the highest-value organic-SEO surface;
    // must be crawlable so they can rank for broad research-intent queries.
    getCategorySitemapEntries(client, {
      siteUrl: baseUrl,
      locales,
      defaultLocale: defaultLoc,
    }).catch(() => []),
    // Blog posts — the SEO Autopilot (and manual publishes) must be
    // discoverable; missing blog entries = articles never get crawled.
    getBlogSitemapEntries(client, {
      siteUrl: baseUrl,
      locales,
      defaultLocale: defaultLoc,
    }).catch(() => []),
    // Merchant-authored content pages (About, policies, …) at /pages/{slug}.
    client.content.page
      .list()
      .then((pages) =>
        pages.flatMap((page) => {
          const slug = (page.data as { slug?: string }).slug;
          if (!slug) return [];
          return [
            {
              url: `${baseUrl}/pages/${slug}`,
              lastModified: page.updatedAt ? new Date(page.updatedAt) : undefined,
              priority: 0.5,
            },
          ];
        })
      )
      .catch(() => []),
  ]);

  return [...staticPages, ...productPages, ...categoryPages, ...blogPages, ...contentPages];
}