import HeroSlider, { type Slide } from "@/components/HeroSlider";
import CategoryCarousel from "@/components/CategoryCarousel";
import HotDeals from "@/components/HotDeals";
import ProductCarousel from "@/components/ProductCarousel";
import { OneBanner, ThreeBanners, TwoBanners } from "@/components/PromoBanners";
import BlogCarousel, { type BlogCardData } from "@/components/BlogCarousel";
import {
  findSlot,
  getBlogs,
  getCategories,
  getProducts,
  getSliders,
  getStaticImageSlots,
  getStoreSpecials,
  safe,
} from "@/lib/api";
import { buildCategoryTree, findNode, subtreeIds } from "@/lib/categoryTree";
import { productToCard, specialToCards } from "@/lib/cards";
import { blogHref, categoryHref } from "@/lib/slug";
import { HOME_CAROUSELS } from "@/data/site";
import { FALLBACK_BLOGS } from "@/data/fallbackBlogs";

// The slider slot is empty on this tenant, so the homepage falls back to the
// campaign banners already running on moalem.shop (same art, same targets).
const FALLBACK_SLIDES: Slide[] = [
  {
    id: "laptop",
    image: "/images/banners/9WYorEOTwn.jpg",
    mobileImage: "/images/banners/WRbs72TDPR.jpg",
    href: categoryHref("1254", "لپ تاپ"),
    alt: "لپ تاپ",
  },
  {
    id: "console",
    image: "/images/banners/OiNl9v5gTf.jpg",
    mobileImage: "/images/banners/ieYGotL2qd.jpg",
    href: categoryHref("1256", "کنسول بازی"),
    alt: "کنسول بازی",
  },
  {
    id: "iphone-17",
    image: "/images/banners/06SQinO4sG.jpg",
    mobileImage: "/images/banners/lAGRh3ks32.jpg",
    href: categoryHref("1251", "موبایل"),
    alt: "آیفون ۱۷ پرو مکس",
  },
];

const EMPTY_PAGE = { items: [], total: 0, page: 1, pageSize: 12 };

export default async function HomePage() {
  const [categories, sliders, specials, blogs, imageSlots] = await Promise.all([
    safe(getCategories().then(buildCategoryTree), []),
    safe(getSliders(), []),
    safe(getStoreSpecials(), []),
    safe(getBlogs({ pageSize: 10 }), { items: [], total: 0, page: 1, pageSize: 10 }),
    safe(getStaticImageSlots("home"), []),
  ]);

  // Empty or failing slots fall through to each section's own placeholder —
  // findSlot() already returns undefined for an empty/missing key.
  const sliderSlot = findSlot(imageSlots, "slider");
  const categoriesSlot = findSlot(imageSlots, "categories");
  const oneBannerSlot = findSlot(imageSlots, "one-banner-bg");
  const twoBannerSlot = findSlot(imageSlots, "two-banner-bg");
  const threeBannerSlot = findSlot(imageSlots, "three-banner-bg");

  const slides: Slide[] =
    sliders.length > 0
      ? sliders
          .filter((s) => s.imageUrl)
          .map((s, i) => ({
            id: s.id ?? `slide-${i}`,
            image: s.imageUrl!,
            mobileImage: s.mobileImageUrl ?? undefined,
            href: s.linkUrl ?? "/products",
            alt: s.title ?? "بنر فروشگاه موبایل معلم",
          }))
      : FALLBACK_SLIDES;

  // "تخفیف‌های داغ" prefers the curated special-discount group; until it is
  // filled in the dashboard it falls back to the newest catalog products.
  const discountGroup =
    specials.find((s) => s.key === "special-discount" && s.isActive) ?? specials[0];
  const dealsFromCms = discountGroup ? specialToCards(discountGroup) : [];
  const fallbackDeals = dealsFromCms.length
    ? []
    : (await safe(getProducts({ pageSize: 12 }), EMPTY_PAGE)).items.map(productToCard);
  const deals = dealsFromCms.length ? dealsFromCms : fallbackDeals;

  const carousels = await Promise.all(
    HOME_CAROUSELS.map(async (section) => {
      const cat = findNode(categories, section.categoryId);
      const ids = cat ? subtreeIds(cat) : [section.categoryId];
      const pages = await Promise.all(
        ids.map((categoryId) => safe(getProducts({ categoryId, pageSize: 12 }), EMPTY_PAGE))
      );

      const seen = new Set<string>();
      const products = pages
        .flatMap((page) => page.items)
        .filter((product) => !seen.has(product.id) && seen.add(product.id))
        .slice(0, 12)
        .map(productToCard);

      return {
        ...section,
        href: categoryHref(section.categoryId, cat?.nameFa ?? section.title, cat?.name),
        products,
      };
    })
  );

  const posts: BlogCardData[] =
    blogs.items.length > 0
      ? blogs.items.map((b) => ({
          id: b.id,
          href: blogHref(b.id, b.title ?? b.nameFa),
          title: b.title ?? b.nameFa ?? "",
          image: b.thumbnailUrl ?? b.image ?? null,
          category: b.categoryNameFa ?? b.categoryName ?? undefined,
        }))
      : FALLBACK_BLOGS.map((b) => ({
          id: b.id,
          href: "/blog",
          title: b.title,
          image: b.image,
          category: b.category,
        }));

  // The deals countdown runs to the end of the current day, recomputed on each
  // server render so the timer never shows a stale target.
  const endOfDay = new Date();
  endOfDay.setHours(23, 59, 59, 999);

  const [mobileCarousel, accessoriesCarousel, laptopCarousel, consoleCarousel] = carousels;

  return (
    <>
      <h1 className="sr-only">فروشگاه موبایل معلم | خرید موبایل، لپ‌تاپ و لوازم جانبی</h1>
      <HeroSlider slot={sliderSlot} slides={slides} />
      <CategoryCarousel roots={categories} slot={categoriesSlot} />
      <HotDeals products={deals} endsAt={endOfDay.getTime() + 2 * 86_400_000} />
      <ThreeBanners slot={threeBannerSlot} />
      {mobileCarousel && (
        <ProductCarousel
          title={mobileCarousel.title}
          desc={mobileCarousel.desc}
          href={mobileCarousel.href}
          products={mobileCarousel.products}
        />
      )}
      <TwoBanners slot={twoBannerSlot} />
      {accessoriesCarousel && (
        <ProductCarousel
          title={accessoriesCarousel.title}
          desc={accessoriesCarousel.desc}
          href={accessoriesCarousel.href}
          products={accessoriesCarousel.products}
        />
      )}
      {laptopCarousel && (
        <ProductCarousel
          title={laptopCarousel.title}
          desc={laptopCarousel.desc}
          href={laptopCarousel.href}
          products={laptopCarousel.products}
        />
      )}
      <OneBanner slot={oneBannerSlot} />
      {consoleCarousel && (
        <ProductCarousel
          title={consoleCarousel.title}
          desc={consoleCarousel.desc}
          href={consoleCarousel.href}
          products={consoleCarousel.products}
        />
      )}
      <BlogCarousel posts={posts} />
    </>
  );
}