/* ============================================================================
   NEWS AND UPDATES - one article
   ----------------------------------------------------------------------------
   /{locale}/news-and-updates/{slug}

   Registered in app/routes.ts as "newsDetail", a SIBLING of the listing route
   under the ":lang" layout, and typed against its generated `./+types/` module.

   A "From the Network" update credits the submitting organisation on the page
   and in the Article JSON-LD, because the draft is explicit that network
   updates are attributed to the CSO that wrote them - the project must not
   appear to be the author of somebody else's work.
   ========================================================================= */

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

import { Button } from "~/components/ui/Button";
import {
  formatDate,
  sectionPath,
  toIsoDate,
  useTranslation,
} from "~/i18n";
import { buildArticleJsonLd, buildBreadcrumbJsonLd, buildMeta } from "~/lib/seo";
import { requireEntity } from "~/lib/strapi";

import type { Route } from "./+types/news-and-updates.$slug";
import {
  collectLocalizedSlugs,
  detailAlternateDescriptors,
  LOCALIZATION_POPULATE,
  SELF_ALTERNATES_HANDLE,
} from "./_shared/alternates";
import { CMS, fetchBySlug, toImage, type NewsEntry } from "./_shared/cms";
import { readRootSeo, requireLocale, withParam } from "./_shared/listing";
import {
  BackLink,
  MetaLine,
  MetaList,
  PageHeader,
  PageShell,
  TopicChips,
  type MetaItem,
} from "./_shared/listing-ui";
import { RichText } from "./_shared/RichText";
import { DETAIL_COPY, NEWS_COPY, NEWS_DETAIL_COPY } from "./_shared/page-copy";

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

/**
 * The Arabic translation of this article has its OWN slug, so the hreflang
 * alternate cannot be built by swapping the locale prefix - see
 * ./_shared/alternates.ts. `localizations` is populated for exactly that.
 */
export const handle = SELF_ALTERNATES_HANDLE;

export async function loader({ params }: Route.LoaderArgs) {
  const locale = requireLocale(params.lang);
  const slug = params.slug ?? "";

  const entry = requireEntity(
    await fetchBySlug<NewsEntry>(CMS.newsArticles, slug, {
      locale,
      populate: {
        coverImage: {
          fields: ["url", "alternativeText", "width", "height", "formats"],
        },
        authorOrganisation: { fields: ["name", "slug"] },
        topics: { fields: ["name", "slug"] },
        localizations: LOCALIZATION_POPULATE,
      },
    }),
  );

  const date = entry.publishDate ?? entry.publishedAt ?? undefined;

  return {
    slug: entry.slug,
    alternates: collectLocalizedSlugs(locale, entry.slug, entry.localizations),
    title: entry.title,
    excerpt: entry.excerpt ?? undefined,
    body: entry.body ?? undefined,
    category: entry.category ?? "sharper-news",
    organisation: entry.authorOrganisation?.name ?? undefined,
    date,
    dateIso: toIsoDate(date),
    dateLabel: date ? formatDate(date, locale) : undefined,
    modifiedIso: toIsoDate(entry.updatedAt),
    topics: (entry.topics ?? [])
      .filter((topic) => Boolean(topic?.slug && topic?.name))
      .map((topic) => ({ label: topic.name, slug: topic.slug })),
    cover: toImage(entry.coverImage, "large"),
  };
}

/* ---------------------------------------------------------------------------
   META
   The shell emits a prefix-swapped canonical + hreflang pair for every route;
   a DETAIL page overrides it, because a Strapi 5 localisation has its own
   slug. `handle = SELF_ALTERNATES_HANDLE` is what tells the shell to stand
   down for this route.
   ------------------------------------------------------------------------ */

export function meta({ matches, loaderData }: Route.MetaArgs) {
  const root = readRootSeo(matches);
  const entry = loaderData as Awaited<ReturnType<typeof loader>> | undefined;
  const section = NEWS_COPY[root.locale];

  if (!entry) {
    return buildMeta({
      locale: root.locale,
      pathname: root.pathname,
      siteUrl: root.siteUrl,
      title: section.heading,
      description: section.metaDescription,
    });
  }

  const sectionLabel =
    entry.category === "from-the-network"
      ? section.networkBlurb
      : section.projectBlurb;

  const descriptors = buildMeta({
    locale: root.locale,
    pathname: root.pathname,
    siteUrl: root.siteUrl,
    title: entry.title,
    description: entry.excerpt ?? sectionLabel,
    type: "article",
    ...(entry.cover ? { image: { url: entry.cover.src, alt: entry.cover.alt } } : {}),
    ...(entry.dateIso
      ? {
          article: {
            publishedTime: entry.dateIso,
            ...(entry.modifiedIso ? { modifiedTime: entry.modifiedIso } : {}),
            ...(entry.organisation ? { authors: [entry.organisation] } : {}),
            tags: entry.topics.map((topic) => topic.label),
          },
        }
      : {}),
    jsonLd: [
      buildBreadcrumbJsonLd(root.siteUrl, [
        { name: "SHARP-ER", pathname: sectionPath("home", root.locale) },
        { name: section.heading, pathname: sectionPath("news", root.locale) },
        { name: entry.title, pathname: root.pathname },
      ]),
      ...(entry.dateIso
        ? [
            buildArticleJsonLd({
              siteUrl: root.siteUrl,
              locale: root.locale,
              headline: entry.title,
              pathname: root.pathname,
              datePublished: entry.dateIso,
              ...(entry.modifiedIso ? { dateModified: entry.modifiedIso } : {}),
              ...(entry.excerpt ? { description: entry.excerpt } : {}),
              ...(entry.cover ? { image: entry.cover.src } : {}),
              // A network update is authored by the CSO that submitted it.
              ...(entry.organisation ? { authorName: entry.organisation } : {}),
              keywords: entry.topics.map((topic) => topic.label),
            }),
          ]
        : []),
    ],
  });

  /* The corrected canonical + hreflang pair, built from the counterpart's real
     slug rather than from this URL with the prefix swapped. */
  return [
    ...descriptors,
    ...detailAlternateDescriptors({
      siteUrl: root.siteUrl,
      section: "news",
      locale: root.locale,
      slugs: entry.alternates,
    }),
  ];
}

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

export default function NewsArticleDetail() {
  const entry = useLoaderData<typeof loader>();
  const { t, locale } = useTranslation();

  const listingPath = sectionPath("news", locale);
  const detail = NEWS_DETAIL_COPY[locale];
  const shared = DETAIL_COPY[locale];

  const streamLabel =
    entry.category === "from-the-network"
      ? t("news.tabNetwork")
      : t("news.tabProject");
  const streamHref = `${listingPath}${withParam(new URLSearchParams(), "tab", entry.category)}`;

  const metaItems: MetaItem[] = [
    ...(entry.dateLabel
      ? [
          {
            label: shared.published,
            value: <time dateTime={entry.dateIso ?? entry.date}>{entry.dateLabel}</time>,
          },
        ]
      : []),
    ...(entry.organisation
      ? [{ label: shared.author, value: entry.organisation }]
      : []),
  ];

  return (
    <PageShell>
      <BackLink to={listingPath} label={detail.backToListing} />

      <article className="flex flex-col gap-2xl">
        <PageHeader eyebrow={streamLabel} heading={entry.title} intro={entry.excerpt}>
          <MetaLine
            items={[
              entry.dateLabel ?? "",
              entry.organisation
                ? t("news.postedBy", { organisation: entry.organisation })
                : "",
            ]}
          />
        </PageHeader>

        {entry.cover ? (
          <img
            src={entry.cover.src}
            alt={entry.cover.alt}
            width={entry.cover.width}
            height={entry.cover.height}
            decoding="async"
            className="w-full rounded-card border border-border-subtle object-cover"
          />
        ) : null}

        <div className="grid gap-2xl lg:grid-cols-[minmax(0,1fr)_18rem] lg:items-start">
          <div className="flex max-w-[var(--layout-prose-max)] flex-col gap-lg">
            <RichText value={entry.body} />

            <div>
              <Button as={Link} to={streamHref} variant="secondary" size="sm">
                {streamLabel}
              </Button>
            </div>
          </div>

          <aside className="flex flex-col gap-lg">
            <MetaList heading={detail.aboutThis} items={metaItems} />
            <TopicChips
              heading={shared.topics}
              topics={entry.topics.map((topic) => ({ label: topic.label }))}
            />
          </aside>
        </div>
      </article>
    </PageShell>
  );
}