import type { PageServerLoad } from './$types';
import { getPageBySlug, getCommentCounts } from '$lib/cms';
import {
  extractCmsImageField,
  ensureTransformedImage,
  resolveContentImages,
  resolveImageUrls,
} from '$lib/rusty-image';
import { buildBannerResponsive, warmResponsiveImage, type ResponsiveImage } from '$lib/rusty-image.server';
import {
  resolvePostOverviewBlocks,
  resolveSearchableTextBlocks,
  resolveCalendarBlocks,
  resolveDeadlineBannerBlocks,
  resolveStellingnahmeGeneratorBlocks,
  resolveAdressbuchBlocks,
} from '$lib/blog-utils';
import { PAGE_RESOLVE, POST_SOCIAL_IMAGE_TRANSFORM } from '$lib/constants';
import { env } from '$env/dynamic/public';
import { error } from '@sveltejs/kit';
import { sanitizeBlocks } from '$lib/sanitize-blocks.server';

function focalToCss(focal: { x: number; y: number } | undefined): string | null {
  if (!focal) return null;
  return `${(focal.x * 100).toFixed(2)}% ${(focal.y * 100).toFixed(2)}%`;
}

export const load: PageServerLoad = async ({ params, locals, fetch, url, setHeaders }) => {
  const { slug } = params;
  const translations = locals.translations ?? {};
  const preview = url.searchParams.get('preview') ?? undefined;
  const previewDraft = url.searchParams.get('preview_draft') ?? undefined;

  if (preview || previewDraft) {
    setHeaders({
      'cache-control': 'private, no-store, max-age=0',
      'x-robots-tag': 'noindex, nofollow',
    });
  } else {
    // Public Pages: Caddy/CDN + Browser cachen 60s, stale-while-revalidate
    // erlaubt 10min Sofort-Lieferung während im Hintergrund neu geholt wird.
    // CMS-Mutationen lösen Webhook → Frontend-Content-Cache-Purge aus, der
    // Edge-Cache läuft per TTL aus (kurze Inkonsistenz akzeptabel).
    setHeaders({
      'cache-control': 'public, s-maxage=60, stale-while-revalidate=600',
    });
  }

  const page = await getPageBySlug(slug, {
    locale: 'de',
    resolve: PAGE_RESOLVE,
    // Hard-cap gegen Cycle-Surprises (page → image → img-Asset reicht in 3
    // Levels). Kein Body-Stripping hier — Page-Detail braucht alle Felder.
    depth: 3,
    preview,
    previewDraft,
  });

  if (!page) {
    error(404, 'Seite nicht gefunden');
  }

  // resolveContentImages baut nur URLs zusammen (kein I/O) und mutiert den
  // Tree — vor den Block-Resolvern erledigen, die danach gegen mutierte
  // Blocks arbeiten.
  await resolveContentImages(page);
  // PostOverview→SearchableText hat Daten-Abhängigkeit (tagsMap). Calendar,
  // DeadlineBanner und StellingnahmeGenerator sind unabhängig — sofort
  // parallel starten, nicht erst nach PostOverview warten.
  const postOverviewPromise = resolvePostOverviewBlocks(page);
  const independentResolvers = Promise.all([
    resolveCalendarBlocks(page),
    resolveDeadlineBannerBlocks(page),
    resolveStellingnahmeGeneratorBlocks(page),
    resolveAdressbuchBlocks(page),
  ]);
  const tagsMap = await postOverviewPromise;
  await Promise.all([
    resolveSearchableTextBlocks(page, tagsMap),
    independentResolvers,
  ]);
  sanitizeBlocks(page);

  // Top-Bild: bevorzugt neues inline-Feld `topImage`, sonst Legacy via
  // topFullwidthBanner-Referenz. Banner-Bild ist auch Social-Image-Quelle.
  let topBannerResolvedImages: string[] = [];
  let topBannerResponsive: ResponsiveImage | null = null;
  let topBannerFocalCss: string | null = null;
  let pageSocialImageAbs: string | null = null;
  const siteBaseUrl = (env.PUBLIC_SITE_URL || '').replace(/\/$/, '');

  const topImageRaw = (page as { topImage?: unknown }).topImage;
  const bannerRaw = (page as { topFullwidthBanner?: unknown }).topFullwidthBanner;
  const topImageSource: unknown =
    topImageRaw ??
    (bannerRaw && typeof bannerRaw === 'object' && 'image' in bannerRaw
      ? (bannerRaw as { image?: unknown }).image
      : undefined);

  if (topImageSource) {
    const imageArr = Array.isArray(topImageSource) ? topImageSource : [topImageSource];
    if (imageArr.length > 0) {
      const primary = extractCmsImageField(imageArr[0]);
      if (primary?.url) {
        topBannerFocalCss = focalToCss(primary.focal);
        topBannerResponsive = await buildBannerResponsive(primary.url, primary.focal);
        const socialRel = ensureTransformedImage(primary.url, {
          ...POST_SOCIAL_IMAGE_TRANSFORM,
          focalX: primary.focal?.x,
          focalY: primary.focal?.y,
        });
        pageSocialImageAbs = socialRel.startsWith('/')
          ? `${siteBaseUrl}${socialRel}`
          : socialRel;
      }
      topBannerResolvedImages = await resolveImageUrls(imageArr as string[], {
        width: 2000,
        height: 750,
        fit: 'cover',
        format: 'webp',
      });
      warmResponsiveImage(topBannerResponsive, fetch);
    }
  }

  const commentsEnabled = !!(page as { commentsEnabled?: boolean }).commentsEnabled;
  const commentPageId = commentsEnabled ? (page._slug ?? slug) : null;
  const commentCount = commentPageId
    ? (await getCommentCounts([commentPageId]))[commentPageId] ?? 0
    : 0;

  return {
    page,
    translations,
    commentPageId,
    commentCount,
    preview: !!preview,
    previewDraft: !!previewDraft,
    seoTitle: page.seoTitle ?? page.headline ?? page.linkName ?? slug,
    seoDescription: page.seoDescription ?? page.subheadline ?? '',
    socialImage: pageSocialImageAbs ?? undefined,
    robots: (page as { seoMetaRobots?: string }).seoMetaRobots ?? undefined,
    keywords: (page as { seoKeywords?: string }).seoKeywords ?? undefined,
    breadcrumbItems: [
      { href: '/', label: 'Start' },
      { label: page.headline ?? page.linkName ?? page.slug ?? page._slug ?? slug },
    ],
    topBanner: topImageSource
      ? {
          banner:
            (bannerRaw as import('$lib/cms').FullwidthBannerEntry | null) ??
            null,
          resolvedImages: topBannerResolvedImages,
          responsive: topBannerResponsive,
          focalCss: topBannerFocalCss,
          headline: page.headline ?? undefined,
          subheadline: page.subheadline ?? undefined,
        }
      : null,
  };
};