/* ============================================================================
   NEWS AND UPDATES - listing
   ----------------------------------------------------------------------------
   /{locale}/news-and-updates

   §5 of docs/SHARPER_Website_Draft_Section_EN_AR.docx, laid out to the 2026
   redesign draft ("News-and-Updates"): an ambient hero, the two-stream tab
   strip, one wide lead card over a three-up grid, and the partner callout.

     Tab 1  SHARP-ER News    ?tab=sharper-news      official project updates
     Tab 2  From the Network ?tab=from-the-network  updates submitted by CSOs
                                            granted as part of the consortium,
                                            each card crediting the
                                            organisation

   The tab values are the `news-article.category` enumeration in the CMS,
   verbatim, so the query string and the Strapi filter cannot drift apart.

   The tabs are LINKS, not client-side state: each stream is its own URL, so it
   can be shared, bookmarked and crawled, and the server renders exactly what
   the address asks for. `aria-current="page"` marks the active one.

   NOTHING FROM THE DRAFT'S SAMPLE FEED IS HERE. Every headline, date, tag,
   excerpt and byline it shows - the launch event, the Misrata sub-project, the
   fact sheet, "30 JUN 2026" - was sample content written for the mockup. Each
   card is built from a Strapi entry or the localised empty state renders
   instead (CLAUDE.md rule 5).
   ========================================================================= */

import { Link, useLocation } from "react-router";

import { Button } from "~/components/ui/Button";
import {
  CardActionHint,
  CardLink,
  CardMedia,
  CardShell,
} from "~/components/ui/Card";
import {
  formatDate,
  sectionPath,
  toIsoDate,
  useTranslation,
  type Locale,
} from "~/i18n";
import { buildBreadcrumbJsonLd, buildMeta } from "~/lib/seo";

import type { Route } from "./+types/news-and-updates";
import {
  CMS,
  NEWS_CATEGORIES,
  fetchCollection,
  taxonomyNames,
  toImage,
  type CmsImage,
  type NewsCategory,
  type NewsEntry,
} from "./_shared/cms";
import {
  PAGE_SIZE,
  buildPagination,
  compactFilters,
  parseEnum,
  parsePage,
  readRootSeo,
  requireLocale,
  withParam,
} from "./_shared/listing";
import {
  CalloutBand,
  EmptyState,
  ListingHero,
  PageShell,
  Pagination,
  ResultSummary,
  TabLinks,
  type TabLink,
} from "./_shared/listing-ui";
import { NEWS_COPY, getListingChrome } from "./_shared/page-copy";

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

/** Tab 1 is the default stream, matching the order of the draft. */
const DEFAULT_TAB: NewsCategory = "sharper-news";

/** `news-article.publishDate` - required in the CMS, so it always sorts. */
const DATE_FIELD = "publishDate";

interface NewsListItem {
  readonly id: string;
  readonly slug: string;
  readonly title: string;
  readonly excerpt?: string;
  readonly organisation?: string;
  readonly date?: string;
  readonly dateLabel?: string;
  /** First topic of the entry - the draft's coloured chip. From the CMS only. */
  readonly tag?: string;
  readonly image?: CmsImage;
}

/* ---------------------------------------------------------------------------
   LOADER
   ------------------------------------------------------------------------ */

export async function loader({ params, request }: Route.LoaderArgs) {
  const locale = requireLocale(params.lang);
  const search = new URL(request.url).searchParams;

  const page = parsePage(search);
  const tab = parseEnum(search, "tab", NEWS_CATEGORIES, DEFAULT_TAB);

  const listing = await fetchCollection<NewsEntry>(CMS.newsArticles, {
    locale,
    filters: compactFilters({ category: { $eq: tab } }),
    sort: [`${DATE_FIELD}:desc`, "title:asc"],
    populate: {
      coverImage: {
        fields: ["url", "alternativeText", "width", "height", "formats"],
      },
      // A relation, not a string: without this the byline is simply absent.
      authorOrganisation: { fields: ["name", "slug"] },
      // Drives the draft's chip above the headline. Nothing is invented: a
      // card with no topic simply has no chip.
      topics: { fields: ["name", "slug"] },
    },
    pagination: { page, pageSize: PAGE_SIZE, withCount: true },
  });

  const entries: NewsListItem[] = listing.entries.map((entry) =>
    toListItem(entry, locale),
  );

  return {
    entries,
    tab,
    pagination: buildPagination(page, PAGE_SIZE, listing.pagination.total),
    available: listing.available,
  };
}

function toListItem(entry: NewsEntry, locale: Locale): NewsListItem {
  const image = toImage(entry.coverImage, "medium");
  const date = entry.publishDate ?? entry.publishedAt ?? undefined;
  const organisation = entry.authorOrganisation?.name;
  const tag = taxonomyNames(entry.topics)[0];

  return {
    id: entry.documentId,
    slug: entry.slug,
    title: entry.title,
    ...(entry.excerpt ? { excerpt: entry.excerpt } : {}),
    ...(organisation ? { organisation } : {}),
    ...(date ? { date, dateLabel: formatDate(date, locale) } : {}),
    ...(tag ? { tag } : {}),
    ...(image ? { image } : {}),
  };
}

/* ---------------------------------------------------------------------------
   META
   The canonical URL and the en/ar/x-default hreflang set are emitted for every
   route by the shell (root.tsx `Layout`), so `alternates` stays off here -
   passing it from a leaf would emit each of those links twice.
   ------------------------------------------------------------------------ */

export function meta({ matches, loaderData }: Route.MetaArgs) {
  const root = readRootSeo(matches);
  const copy = NEWS_COPY[root.locale];

  return buildMeta({
    locale: root.locale,
    pathname: root.pathname,
    siteUrl: root.siteUrl,
    title: copy.heading,
    description: copy.metaDescription,
    // If the CMS could not be reached the page is an empty shell, not an empty
    // section - keep it out of the index rather than teaching a crawler that
    // SHARP-ER has published nothing.
    noIndex: loaderData?.available === false,
    jsonLd: buildBreadcrumbJsonLd(root.siteUrl, [
      { name: "SHARP-ER", pathname: sectionPath("home", root.locale) },
      { name: copy.heading, pathname: sectionPath("news", root.locale) },
    ]),
  });
}

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

export default function NewsAndUpdates({ loaderData }: Route.ComponentProps) {
  const { entries, pagination, tab } = loaderData;
  const { t, locale } = useTranslation();
  const { pathname, search } = useLocation();
  const params = new URLSearchParams(search);

  const copy = NEWS_COPY[locale];
  const chrome = getListingChrome(locale).news;
  const empty = new URLSearchParams();

  const tabs: TabLink[] = [
    {
      id: "sharper-news",
      label: t("news.tabProject"),
      href: `${pathname}${withParam(empty, "tab", "sharper-news")}`,
      isCurrent: tab === "sharper-news",
    },
    {
      id: "from-the-network",
      label: t("news.tabNetwork"),
      href: `${pathname}${withParam(empty, "tab", "from-the-network")}`,
      isCurrent: tab === "from-the-network",
    },
  ];

  /* The draft leads the page with one wide card. It is the newest entry of the
     stream, and only on page 1 - page 4 of an archive has no "lead story". */
  const isFirstPage = pagination.page === 1;
  const [lead, ...rest] = entries;
  const featured = isFirstPage ? lead : undefined;
  const grid = featured ? rest : entries;

  const hrefOf = (entry: NewsListItem) =>
    `${sectionPath("news", locale)}/${entry.slug}`;

  return (
    <>
      <ListingHero
        eyebrow={chrome.eyebrow}
        heading={copy.heading}
        intro={copy.intro}
        ambient={[{ top: -250, from: "start", offset: "8%", width: 720, height: 560, durationSeconds: 20 }]}
      />

      <PageShell>
        <section className="flex flex-col gap-lg" aria-label={copy.heading}>
          <TabLinks label={t("nav.sections.news")} tabs={tabs} />

          <p className="body-md max-w-[var(--layout-prose-max)] text-text-secondary">
            {tab === "from-the-network" ? copy.networkBlurb : copy.projectBlurb}
          </p>

          <ResultSummary pagination={pagination} t={t} />

          {entries.length === 0 ? (
            <EmptyState title={copy.emptyTitle} body={copy.emptyBody}>
              {tab === "from-the-network" ? (
                <Button
                  as={Link}
                  to={sectionPath("contact", locale)}
                  variant="secondary"
                  size="sm"
                >
                  {t("actions.submitYourUpdate")}
                </Button>
              ) : null}
            </EmptyState>
          ) : (
            <>
              {featured ? (
                <>
                  <h2 className="sr-only">{chrome.featuredLabel}</h2>
                  <FeaturedNewsCard
                    entry={featured}
                    href={hrefOf(featured)}
                    actionLabel={chrome.readFull}
                  />
                </>
              ) : null}

              {grid.length > 0 ? (
                <>
                  <h2 className="sr-only">{chrome.moreLabel}</h2>
                  <ul className="grid gap-lg sm:grid-cols-2 lg:grid-cols-3">
                    {grid.map((entry) => (
                      <NewsCard
                        key={entry.id}
                        entry={entry}
                        href={hrefOf(entry)}
                        creditLabel={
                          entry.organisation
                            ? t("news.postedBy", {
                                organisation: entry.organisation,
                              })
                            : undefined
                        }
                      />
                    ))}
                  </ul>
                </>
              ) : null}
            </>
          )}

          <Pagination model={pagination} pathname={pathname} params={params} t={t} />
        </section>

        {/* "Are you a partner organisation? Submit your update ->" - §5 of the
            draft. It points at Contact, which is where a submission is handled
            until the CMS grows a submission form. */}
        <CalloutBand
          eyebrow={t("news.tabNetwork")}
          headline={t("news.partnerPrompt")}
          body={copy.networkBlurb}
          action={{
            to: sectionPath("contact", locale),
            label: t("actions.submitYourUpdate"),
          }}
        />
      </PageShell>
    </>
  );
}

/* ---------------------------------------------------------------------------
   THE TWO CARDS
   Composed from the exported card primitives rather than Card.Content: the
   draft's newsroom cards carry a chip-and-date row above the headline and a
   credit line pinned to the foot, neither of which that card has a slot for.
   ------------------------------------------------------------------------ */

/** The chip-and-date row. Both halves are optional and both come from Strapi. */
function NewsMetaRow({ entry }: { entry: NewsListItem }) {
  if (!entry.tag && !entry.dateLabel) return null;

  return (
    <div className="flex flex-wrap items-center gap-sm">
      {entry.tag ? (
        <span className="rounded-chip bg-surface-accent-subtle px-xs py-2xs label-md uppercase text-text-accent">
          {entry.tag}
        </span>
      ) : null}

      {entry.dateLabel ? (
        <time
          dateTime={toIsoDate(entry.date)}
          className="label-md text-text-tertiary"
        >
          {entry.dateLabel}
        </time>
      ) : null}
    </div>
  );
}

/** The wide lead card: picture beside the story, stacked on a phone. */
function FeaturedNewsCard({
  entry,
  href,
  actionLabel,
}: {
  entry: NewsListItem;
  href: string;
  actionLabel: string;
}) {
  return (
    <CardShell
      linked
      className="sh-reveal sh-reveal--in flex-col overflow-hidden md:flex-row"
    >
      {entry.image ? (
        <div className="relative md:w-1/2 md:shrink-0">
          <CardMedia image={entry.image} className="aspect-[16/10] w-full md:h-full" />
          {/* The highlight travelling across the picture - the draft's sheen. */}
          <span
            aria-hidden="true"
            className="sh-sheen pointer-events-none absolute inset-0 bg-[linear-gradient(100deg,transparent_35%,var(--overlay-veil)_50%,transparent_65%)]"
          />
        </div>
      ) : null}

      <div className="flex flex-1 flex-col justify-center gap-md p-xl">
        <NewsMetaRow entry={entry} />

        <h3 className="sh-card-title heading-h3 text-text-primary">
          <CardLink href={href} className="sh-card-link">
            {entry.title}
          </CardLink>
        </h3>

        {entry.excerpt ? (
          <p className="body-md text-text-secondary">{entry.excerpt}</p>
        ) : null}

        <CardActionHint label={actionLabel} />
      </div>
    </CardShell>
  );
}

/** One card of the three-up grid. */
function NewsCard({
  entry,
  href,
  creditLabel,
}: {
  entry: NewsListItem;
  href: string;
  creditLabel?: string;
}) {
  return (
    <CardShell
      as="li"
      linked
      className="sh-reveal sh-reveal--in flex-col overflow-hidden"
    >
      {entry.image ? (
        <CardMedia image={entry.image} className="aspect-[9/5] w-full" />
      ) : null}

      <div className="flex flex-1 flex-col gap-md p-lg">
        <div className="flex flex-col gap-xs">
          <NewsMetaRow entry={entry} />

          <h3 className="sh-card-title body-lg-bold text-text-primary">
            <CardLink href={href} className="sh-card-link">
              {entry.title}
            </CardLink>
          </h3>

          {entry.excerpt ? (
            <p className="body-sm text-text-secondary line-clamp-3">
              {entry.excerpt}
            </p>
          ) : null}
        </div>

        {/* The draft closes the small card with the crediting byline and
            nothing else - the read-more affordance belongs to the lead card
            only, and the headline is already the link. */}
        {creditLabel ? (
          <p className="mt-auto label-md uppercase text-text-tertiary">
            {creditLabel}
          </p>
        ) : null}
      </div>
    </CardShell>
  );
}