/* ============================================================================
   HOME  -  /en  and  /ar
   ----------------------------------------------------------------------------
   The redesigned home page (Claude Design "Home page redesign with news and
   FAQs", third drop), carried onto the project's own design system. Six bands,
   alternating the two dark surfaces the way the draft alternates #0B0B0A and
   #1D1D1B:

     Hero          EU badge, an optional status pill, the headline, the lead,
                   the CTA pair, the wide picture and the brand stripe. Two
                   slow washes drift behind it.
     Approach      "A nationwide project, delivered locally": what the project
                   does, and up to three pictures. Heading, lead and pictures
                   are all `home-page.approach`, so the band is edited in one
                   place rather than half in a field and half in Blocks.
     Work          "Three areas of change" - the three approved pillars, with
                   a link through to What We Do.
     Newsroom      three cards from the newsroom, newest first.
     FAQs          a sticky heading column beside the accordion.
     Consortium    the three members, then the civil society network logos.

   WHAT THE DRAFT SHIPS THAT THIS PAGE DOES NOT
   --------------------------------------------
   * The draft's FAQ column promises a reply "within five working days". That
     commitment appears in no approved document, so it is not published
     (CLAUDE.md rule 5). Everything else in the draft is verifiable against
     docs/ or the bundled draft copy.
   * The figures band the second drop carried is gone, as it is from the third
     draft, and so is the `home-page.stats` component behind it: no approved
     document carries a number, so there was never anything to put in it.
   * Every list - news, questions, partner logos, band pictures - is CMS
     data, never the draft's sample entries. Each band shows its localised
     empty state instead of inventing content.
   * The draft's own navigation and footer are ignored: the site ships
     <Navigation /> and <Footer /> from the app shell.

   MOTION: every animation in the draft is here, as classes from
   _page-kit/motion.css - the headline wipe, the hero picture's scroll-driven
   drift, the gallery and card hovers, the logo marquee. The one effect
   deliberately dropped is the coloured glow behind a hovered button or card.

   There is no Arabic frame, so /ar is this same DOM under `dir="rtl"`, which
   is why every inline edge below is logical (ps-/pe-/start-/end-).
   ========================================================================= */

import { Link } from "react-router";

import { ArrowIcon, Button } from "~/components/ui/Button";
import { Card } from "~/components/ui/Card";
import { EuBadge } from "~/components/ui/EuBadge";
import {
  createTranslator,
  formatDate,
  getMessages,
  sectionPath,
  type Locale,
} from "~/i18n";
import {
  buildMeta,
  buildOrganizationJsonLd,
  buildWebSiteJsonLd,
} from "~/lib/seo";
import { safeHref } from "~/lib/safe-href";

import type { Route } from "./+types/home";
import { Accordion } from "./_page-kit/accordion";
import {
  isImageGalleryBlock,
  type CmsFaq,
  type CmsHomePage,
  type CmsNewsArticle,
  type CmsPartner,
} from "./_page-kit/cms-types";
import {
  list,
  loadMany,
  loadSingle,
  toImage,
  toPartner,
  type ResolvedImage,
  type ResolvedPartner,
} from "./_page-kit/cms.server";
import { pageCopy } from "./_page-kit/copy";
import { routeLocale } from "./_page-kit/locale";
import {
  Container,
  cx,
  EmptyState,
  PageHero,
  PageSection,
  SectionHeader,
} from "./_page-kit/sections";

import "./_page-kit/motion.css";

/** The network logo wall - a wide but finite grid. */
const PARTNER_PAGE_SIZE = 36;
/**
 * Below this many partners the wall stays a grid.
 *
 * The marquee loops by carrying the tiles twice and sliding exactly half the
 * track, which only reads as a loop while the half is wider than the frame it
 * slides through. Eight 178px tiles clear a desktop container; fewer would
 * drift a short row across an empty band, so the grid keeps them still.
 */
const PARTNER_MARQUEE_MIN = 8;
/** The draft's newsroom band is a straight three-up row. */
const NEWS_PAGE_SIZE = 3;
/** More than a dozen questions is a page of its own, not a home page band. */
const FAQ_PAGE_SIZE = 12;
/** The draft's approach band shows three pictures. */
const GALLERY_SHOTS = 3;

/** A newsroom card, already localised and safe to serialise to the client. */
interface NewsCard {
  id: string;
  title: string;
  href: string;
  excerpt: string | null;
  dateLabel: string | null;
  organisation: string | null;
  image: { src: string; alt: string } | null;
}

function toNewsCard(article: CmsNewsArticle, locale: Locale): NewsCard {
  const image = toImage(article.coverImage, "small");

  return {
    id: article.documentId,
    title: article.title,
    href: `${sectionPath("news", locale)}/${article.slug}`,
    excerpt: article.excerpt ?? null,
    /* The CMS holds one date for both languages; the reader's locale decides
       how it is written out. */
    dateLabel: article.publishDate ? formatDate(article.publishDate, locale) : null,
    organisation: article.authorOrganisation?.name ?? null,
    image: image ? { src: image.src, alt: image.alt } : null,
  };
}

export async function loader({ params }: Route.LoaderArgs) {
  const locale = routeLocale(params);

  const page = await loadSingle<CmsHomePage>("home-page", {
    locale,
    populate: {
      hero: { populate: { media: true, ctas: true } },
      approach: { populate: { images: true } },
      // Strapi 5 populates a dynamic zone per component with `on`.
      blocks: { on: { "blocks.image-gallery": { populate: { images: true } } } },
      featuredNews: { populate: { coverImage: true, authorOrganisation: true } },
      partners: { populate: { logo: true, logoDark: true } },
      seo: { populate: { ogImage: true } },
    },
  });

  /* The curated relation wins; otherwise show every partner the CMS knows, so
     the wall fills in as soon as partners exist - before anyone remembers to
     curate the home page itself. */
  const curatedPartners = list(page?.partners);
  const partners =
    curatedPartners.length > 0
      ? curatedPartners
      : await loadMany<CmsPartner>("partners", {
          locale,
          sort: ["name:asc"],
          filters: { partnerRole: { $in: ["cso-partner", "institution"] } },
          populate: { logo: true, logoDark: true },
          pagination: { pageSize: PARTNER_PAGE_SIZE },
        });

  /* Same rule for the newsroom: an editor's picks, else simply the newest
     articles, so the band is never empty while the newsroom has entries. */
  const curatedNews = list(page?.featuredNews);
  const news =
    curatedNews.length > 0
      ? curatedNews
      : await loadMany<CmsNewsArticle>("news-articles", {
          locale,
          sort: ["publishDate:desc", "title:asc"],
          populate: { coverImage: true, authorOrganisation: true },
          pagination: { pageSize: NEWS_PAGE_SIZE },
        });

  const faqs = await loadMany<CmsFaq>("faqs", {
    locale,
    sort: ["order:asc", "createdAt:asc"],
    pagination: { pageSize: FAQ_PAGE_SIZE },
  });

  /* The band's own pictures come first. An `image-gallery` block is still
     read after them, so a gallery an editor built in the Blocks zone before
     the band had a media field of its own keeps rendering. */
  const gallery = [
    ...list(page?.approach?.images),
    ...list(page?.blocks)
      .filter(isImageGalleryBlock)
      .flatMap((block) => list(block.images)),
  ]
    .map((image) => toImage(image, "medium"))
    .filter((image): image is ResolvedImage => image !== undefined);

  return {
    locale,
    hero: {
      eyebrow: page?.hero?.eyebrow ?? null,
      headline: page?.hero?.headline ?? null,
      subheading: page?.hero?.subheading ?? null,
      media: toImage(page?.hero?.media, "large") ?? null,
      ctas: list(page?.hero?.ctas).map((cta) => ({
        label: cta.label,
        href: cta.href,
        variant: cta.variant ?? "primary",
      })),
    },
    approach: {
      eyebrow: page?.approach?.eyebrow ?? null,
      heading: page?.approach?.heading ?? null,
      lead: page?.approach?.lead ?? null,
    },
    gallery: gallery.slice(0, GALLERY_SHOTS),
    partnersHeadline: page?.partnersHeadline ?? null,
    partners: partners.map(toPartner),
    news: news.slice(0, NEWS_PAGE_SIZE).map((article) => toNewsCard(article, locale)),
    faqs: faqs.map((faq) => ({
      id: faq.documentId,
      question: faq.question,
      answer: faq.answer,
    })),
    seo: {
      title: page?.seo?.metaTitle ?? null,
      description: page?.seo?.metaDescription ?? null,
      image: toImage(page?.seo?.ogImage, "large") ?? null,
      noIndex: page?.seo?.noIndex ?? false,
    },
  };
}

export function meta({ loaderData, matches }: Route.MetaArgs) {
  const root = matches[0].loaderData;
  const locale = loaderData?.locale ?? root.locale;
  const messages = getMessages(locale);

  return buildMeta({
    locale,
    pathname: root.pathname,
    siteUrl: root.siteUrl,
    title: loaderData?.seo.title ?? messages.site.metaTitle,
    description: loaderData?.seo.description ?? messages.site.description,
    ...(loaderData?.seo.image
      ? { image: { url: loaderData.seo.image.src, alt: loaderData.seo.image.alt } }
      : {}),
    noIndex: loaderData?.seo.noIndex ?? false,
    // Emitted once for the whole site, from its home page.
    jsonLd: [
      buildOrganizationJsonLd({ siteUrl: root.siteUrl, locale }),
      buildWebSiteJsonLd({ siteUrl: root.siteUrl, locale }),
    ],
  });
}

/* ---------------------------------------------------------------------------
   SMALL PIECES
   ------------------------------------------------------------------------ */

interface HeroCtaProps {
  href: string;
  label: string;
  variant: "primary" | "secondary";
}

/**
 * A hero call to action.
 *
 * Both controls are the project's Button, which now carries the Claude Design
 * drafts' own treatment: the accent fill for the primary, the outline ring for
 * the secondary, and a 3px lift under the pointer. The secondary is no longer
 * flipped onto the light surface - the drafts draw it as an outline on the
 * dark band, not as a white fill.
 */
function HeroCta({ href, label, variant }: HeroCtaProps) {
  return (
    <Button
      as={Link}
      to={href}
      prefetch="intent"
      size="lg"
      variant={variant}
      iconEnd={variant === "primary" ? <ArrowIcon /> : undefined}
    >
      {label}
    </Button>
  );
}

/**
 * The hero's status line. The draft hard-codes "Now live · Expression of
 * Interest open"; here the words are the CMS hero eyebrow, so the pill only
 * ever announces a state an editor has actually written - and the hero simply
 * has no pill until then. The dot pulses; the text does not move.
 */
function StatusPill({ label }: { label: string }) {
  return (
    <span className="inline-flex items-center gap-xs rounded-pill border border-[var(--border-subtle)] bg-[var(--surface-raised)] py-2xs ps-sm pe-md">
      <span
        aria-hidden="true"
        className="sh-pulse size-[7px] shrink-0 rounded-pill bg-[var(--surface-accent)]"
      />
      <span className="label-md uppercase text-[var(--text-secondary)]">{label}</span>
    </span>
  );
}

/**
 * The approach band's three pictures. The CMS alt text doubles as the visible
 * caption - so the picture is described once, in the caption, and the <img>
 * itself is marked decorative rather than having a screen reader read the same
 * sentence twice.
 *
 * The frame and the picture hover apart, as the third draft has them: the
 * frame lifts and takes the accent hairline (`sh-lift`) while the picture
 * closes in inside it (`sh-zoom`, which also does the clipping).
 */
function GalleryShots({ images }: { images: readonly ResolvedImage[] }) {
  if (images.length === 0) return null;

  return (
    <ul className="grid list-none grid-cols-1 gap-lg sm:grid-cols-2 lg:grid-cols-3">
      {images.map((image) => (
        <li key={image.src} className="sh-reveal">
          <figure className="flex flex-col gap-xs">
            <div className="sh-lift sh-zoom rounded-control border border-[var(--border-subtle)] hover:border-[var(--border-accent)]">
              <img
                src={image.src}
                alt=""
                loading="lazy"
                className="h-[15rem] w-full object-cover"
              />
            </div>
            {image.alt ? (
              <figcaption className="body-sm-bold text-[var(--text-secondary)]">
                {image.alt}
              </figcaption>
            ) : null}
          </figure>
        </li>
      ))}
    </ul>
  );
}

/**
 * One tile on the civil society logo wall.
 *
 * `decorative` renders the second half of the marquee track: the same tile,
 * hidden from assistive technology, with no link and no alt text, so the loop
 * repeats visually without repeating the wall for a screen reader or adding a
 * second tab stop per partner.
 */
function PartnerTile({
  partner,
  fixedWidth = false,
  decorative = false,
}: {
  partner: ResolvedPartner;
  fixedWidth?: boolean;
  decorative?: boolean;
}) {
  const href = decorative ? undefined : safeHref(partner.website);

  /* The logo wall is a wall of equal tiles; the name is the tile's text when
     there is no logo to draw, and always its accessible name. */
  const inner = partner.logo ? (
    <img
      src={partner.logo.src}
      alt={decorative ? "" : partner.name}
      loading="lazy"
      className="max-h-[3.5rem] w-auto max-w-full object-contain"
    />
  ) : (
    <span className="body-sm-bold text-center text-[var(--text-secondary)]">
      {partner.name}
    </span>
  );

  return (
    <li
      {...(decorative ? { "aria-hidden": true } : {})}
      className={cx(
        "flex h-[5.5rem] items-center justify-center",
        "rounded-control border border-[var(--border-subtle)] bg-[var(--surface-card)] p-md",
        "transition-colors duration-[var(--motion-duration-base)]",
        "hover:border-[var(--border-accent)]",
        /* A still grid reveals tile by tile; a travelling track must not, or
           each tile would ramp its own opacity while it moves.

           The track's spacing is a margin on the tile rather than a `gap` on
           the row: the loop slides exactly half the track, so each half has to
           carry its own trailing space or the seam lands half a gap short. */
        fixedWidth ? "me-md w-[11.125rem] shrink-0" : "sh-reveal sh-reveal--in",
        decorative && "sh-marquee__clone",
      )}
    >
      {href ? (
        <a
          href={href}
          target="_blank"
          rel="noopener noreferrer"
          className="flex h-full w-full items-center justify-center"
        >
          {inner}
        </a>
      ) : (
        inner
      )}
    </li>
  );
}

/** The "see the whole section" link the draft puts opposite a band heading. */
function BandLink({ to, label }: { to: string; label: string }) {
  return (
    <Button as={Link} to={to} prefetch="intent" variant="ghost" iconEnd={<ArrowIcon />}>
      {label}
    </Button>
  );
}

/* ---------------------------------------------------------------------------
   THE PAGE
   ------------------------------------------------------------------------ */

export default function Home({ loaderData }: Route.ComponentProps) {
  const { locale, hero, approach, gallery, partners, news, faqs } = loaderData;
  const t = createTranslator(locale);
  const copy = pageCopy(locale).home;
  /* The three pillars are the About page's approved copy - one source, so the
     two pages can never drift apart. */
  const pillars = pageCopy(locale).about.pillars;

  const headline = hero.headline ?? copy.heroHeadline;
  const lead = hero.subheading ?? copy.heroLead;
  const consortiumHeading = loaderData.partnersHeadline ?? copy.consortiumHeading;

  /* The frame draws one accent CTA and one white one. Editor-supplied CTAs go
     through the same component as the fallback pair, so a `secondary` CTA
     authored in Strapi gets the white treatment too. */
  const heroCtas: readonly HeroCtaProps[] =
    hero.ctas.length > 0
      ? hero.ctas.map((cta) => ({
          href: cta.href,
          label: cta.label,
          variant: cta.variant === "primary" ? "primary" : "secondary",
        }))
      : [
          {
            href: sectionPath("applications", locale),
            label: copy.heroCtaPrimary,
            variant: "primary",
          },
          {
            href: sectionPath("about", locale),
            label: copy.heroCtaSecondary,
            variant: "secondary",
          },
        ];

  return (
    <>
      {/* The reading-progress rule. Decorative, pointer-transparent, and
          painted only where scroll timelines exist (motion.css). */}
      <div
        aria-hidden="true"
        className="sh-progress pointer-events-none fixed inset-x-0 top-0 z-[var(--layer-dropdown)] h-[3px]"
      />

      <PageHero
        className="bg-[var(--surface-sunken)] [--layout-hero-top:clamp(2.5rem,6vw,4.5rem)] [--layout-hero-bottom:var(--spacing-md)]"
        title={headline}
        lead={lead}
        leadWithActions
        {...(hero.eyebrow ? { statusPill: <StatusPill label={hero.eyebrow} /> } : {})}
        ambient={[
          { top: -220, from: "start", offset: "8%", width: 780, height: 620, durationSeconds: 18 },
          {
            top: 120,
            from: "end",
            offset: "-160px",
            width: 620,
            height: 520,
            tone: "danger",
            durationSeconds: 24,
            reverse: true,
          },
        ]}
        reveal
        /* EU visibility sits at the top of the hero (the draft's badge). The
           emblem is the dark-surface export because the hero sits on the
           page's own dark surface. `emblemAlt` is left at its empty default:
           the statement is real text beside the emblem, so naming the image
           would read the attribution out twice. */
        funderBadge={
          <EuBadge
            size="sm"
            statement={t("site.euStatement")}
            locale={locale}
            surface="dark"
            className="self-start"
          />
        }
        {...(hero.media ? { media: hero.media } : {})}
        mediaTreatment="banner"
        actions={heroCtas.map((cta) => (
          <HeroCta key={`${cta.href}-${cta.label}`} {...cta} />
        ))}
      />

      {/* WHAT THE PROJECT IS, AND WHO DELIVERS IT */}
      <PageSection
        aria-labelledby="home-approach-heading"
        band
      >
        <div className="flex flex-col gap-3xl">
          <div className="sh-reveal mx-auto flex max-w-[55rem] flex-col items-center gap-lg text-center">
            <SectionHeader
              id="home-approach-heading"
              eyebrow={approach.eyebrow ?? copy.approachEyebrow}
              title={approach.heading ?? copy.approachHeading}
              size="display"
              align="center"
            />

            <p className="body-lg text-[var(--text-secondary)]">
              {approach.lead ?? copy.approachLead}
            </p>
          </div>

          <GalleryShots images={gallery} />
        </div>
      </PageSection>

      {/* THREE AREAS OF CHANGE */}
      <PageSection
        aria-labelledby="home-work-heading"
        className="bg-[var(--surface-sunken)]"
      >
        <div className="flex flex-col gap-2xl">
          <div className="sh-reveal flex flex-wrap items-end justify-between gap-lg border-b border-[var(--border-default)] pb-lg">
            <SectionHeader
              id="home-work-heading"
              title={copy.workHeading}
              size="display"
            />

            <BandLink to={sectionPath("whatWeDo", locale)} label={copy.workLinkLabel} />
          </div>

          <ul className="grid list-none grid-cols-1 gap-lg md:grid-cols-3">
            {pillars.map((pillar) => (
              <li
                key={pillar.title}
                /* `sh-rule-top` draws the draft's accent rule across the top
                   of the tile as the pointer arrives. */
                className="sh-lift sh-reveal sh-reveal--in sh-rule-top flex h-full flex-col gap-sm rounded-card border border-[var(--border-subtle)] bg-[var(--surface-card)] p-xl hover:border-[var(--border-accent)]"
              >
                <h3 className="heading-h3 text-[var(--text-primary)]">{pillar.title}</h3>
                <p className="body-md text-[var(--text-secondary)]">
                  {pillar.description}
                </p>
              </li>
            ))}
          </ul>
        </div>
      </PageSection>

      {/* NEWSROOM */}
      <PageSection
        aria-labelledby="home-news-heading"
        band
      >
        <div className="flex flex-col gap-2xl">
          <div className="sh-reveal flex flex-wrap items-end justify-between gap-lg border-b border-[var(--border-default)] pb-lg">
            <SectionHeader
              id="home-news-heading"
              eyebrow={copy.newsEyebrow}
              title={copy.newsHeading}
              size="display"
            />

            <BandLink to={sectionPath("news", locale)} label={t("actions.viewAll")} />
          </div>

          {news.length > 0 ? (
            <ul className="grid list-none grid-cols-1 gap-lg sm:grid-cols-2 lg:grid-cols-3">
              {news.map((item) => (
                <Card.Content
                  key={item.id}
                  as="li"
                  className="sh-reveal sh-reveal--in"
                  href={item.href}
                  title={item.title}
                  actionLabel={t("actions.readMore")}
                  {...(item.organisation
                    ? { eyebrow: t("news.postedBy", { organisation: item.organisation }) }
                    : item.dateLabel
                      ? { eyebrow: item.dateLabel }
                      : {})}
                  {...(item.organisation && item.dateLabel
                    ? { badge: item.dateLabel }
                    : {})}
                  {...(item.excerpt ? { excerpt: item.excerpt } : {})}
                  {...(item.image ? { image: item.image } : {})}
                  titleAs="h3"
                />
              ))}
            </ul>
          ) : (
            <EmptyState message={copy.newsEmpty} />
          )}
        </div>
      </PageSection>

      {/* FAQs - the heading column stays with the reader while the answers
          scroll beside it, as the draft has it. */}
      <PageSection
        aria-labelledby="home-faq-heading"
        className="bg-[var(--surface-sunken)]"
      >
        <div className="grid grid-cols-1 gap-2xl lg:grid-cols-2 lg:gap-4xl">
          <div className="sh-reveal flex flex-col gap-lg lg:sticky lg:top-[var(--layout-sticky-top)] lg:self-start">
            <SectionHeader
              id="home-faq-heading"
              eyebrow={copy.faqEyebrow}
              title={copy.faqHeading}
              lead={copy.faqLead}
              size="display"
            />

            <Button
              as={Link}
              to={sectionPath("knowledgeHub", locale)}
              prefetch="intent"
              size="lg"
              className="self-start"
              iconEnd={<ArrowIcon />}
            >
              {copy.faqCtaLabel}
            </Button>
          </div>

          {faqs.length > 0 ? (
            <Accordion items={faqs} className="sh-reveal" />
          ) : (
            <EmptyState message={copy.faqEmpty} />
          )}
        </div>
      </PageSection>

      {/* THE CONSORTIUM, then the network it works with */}
      <PageSection
        aria-labelledby="home-consortium-heading"
        band
      >
        <div className="flex flex-col gap-2xl">
          <div className="sh-reveal flex flex-wrap items-end justify-between gap-lg">
            <SectionHeader
              id="home-consortium-heading"
              title={consortiumHeading}
              size="display"
            />

            <p className="label-md uppercase text-[var(--text-tertiary)]">
              {t("site.euStatement")}
            </p>
          </div>

          <ul className="grid list-none grid-cols-1 gap-lg md:grid-cols-3">
            {copy.consortium.map((member) => (
              <li
                key={member.name}
                className="sh-lift sh-reveal sh-reveal--in flex h-full flex-col items-start gap-sm rounded-card border border-[var(--border-subtle)] bg-[var(--surface-card)] p-xl hover:border-[var(--border-accent)]"
              >
                <span className="rounded-chip bg-[var(--surface-accent-subtle)] px-xs py-2xs label-md uppercase text-[var(--text-accent)]">
                  {member.role}
                </span>
                <h3 className="heading-h3 text-[var(--text-primary)]">{member.name}</h3>
                <p className="body-md text-[var(--text-secondary)]">
                  {member.description}
                </p>
              </li>
            ))}
          </ul>

          <div className="flex flex-col gap-md">
            <h3 className="label-md uppercase text-[var(--text-tertiary)]">
              {copy.networkLabel}
            </h3>

            {partners.length === 0 ? (
              <EmptyState message={copy.partnersEmpty} />
            ) : partners.length >= PARTNER_MARQUEE_MIN ? (
              /* The wall drifts, as the third draft draws it. The track holds
                 the tiles twice so the loop is seamless; the mask fades it out
                 at both ends instead of cutting a tile in half. Both halves
                 come from one list, so the wall can never show a partner the
                 CMS does not hold. */
              <div className="sh-marquee-mask relative overflow-hidden">
                <ul className="sh-marquee flex list-none">
                  {partners.map((partner) => (
                    <PartnerTile key={partner.id} partner={partner} fixedWidth />
                  ))}
                  {partners.map((partner) => (
                    <PartnerTile
                      key={`repeat-${partner.id}`}
                      partner={partner}
                      fixedWidth
                      decorative
                    />
                  ))}
                </ul>
              </div>
            ) : (
              <ul className="grid list-none grid-cols-2 gap-md sm:grid-cols-3 lg:grid-cols-4">
                {partners.map((partner) => (
                  <PartnerTile key={partner.id} partner={partner} />
                ))}
              </ul>
            )}
          </div>
        </div>
      </PageSection>
    </>
  );
}