import type { Metadata } from 'next';
import Link from 'next/link';
import { redirect } from 'next/navigation';
import { BenchmarksFilterRail } from '@/components/benchmarks/filter-rails';
import { TerminalLayout } from '@/components/layout/terminal';
import { ScrollX } from '@/components/models/scroll-x';
import { TrustBadge } from '@/components/models/badges';
import { fmtScoreUnit } from '@/components/models/shared';
import { ComparabilityLegend } from '@/components/entity/model-blocks';
import { EntityLink } from '@/components/ui/entity';
import { Hint } from '@/components/ui/hint';
import { Container, Note } from '@/components/ui/section';
import { EmptyState, Unavailable } from '@/components/ui/unavailable';
import { apiD1, safe } from '@/lib/api';
import { cn } from '@/lib/cn';
import { fmtAgo, fmtInt, num } from '@/lib/format';
import { routes, SITE_NAME, SITE_URL } from '@/lib/site';
import type { BenchmarkListItem } from '@/lib/types';

export const metadata: Metadata = {
  title: 'AI benchmarks — leaderboards, comparability groups & current leaders',
  description: 'Every benchmark in the atlas grouped by family and variant: metric and direction, current results, distinct models, the current recorded leader with its trust level — one row per canonical model, never compared across configurations.',
  alternates: { canonical: '/benchmarks' },
  openGraph: { title: `AI benchmarks — leaderboards, comparability groups & current leaders | ${SITE_NAME}`, url: `${SITE_URL}/benchmarks`, type: 'website' },
};
export const revalidate = 300;

type SP = { category?: string; view?: string; q?: string; with_results?: string };

function familyOf(b: BenchmarkListItem): string {
  return b.family ?? b.slug;
}

export default async function BenchmarksPage({ searchParams }: { searchParams: Promise<SP> }) {
  const sp = await searchParams;
  if (sp.view === 'matrix') redirect('/benchmarks/matrix');
  const category = sp.category?.trim() || undefined;
  const q = sp.q?.trim().toLowerCase() || undefined;
  const withResults = sp.with_results === '1';
  const [res, meth] = await Promise.all([safe(apiD1.benchmarks()), safe(apiD1.methodology())]);
  const all = res?.items ?? [];
  const cats = new Map<string, number>();
  for (const b of all) if (b.category) cats.set(b.category, (cats.get(b.category) ?? 0) + 1);
  const catList = [...cats.entries()].sort((x, y) => y[1] - x[1] || x[0].localeCompare(y[0]));
  let items = category ? all.filter((b) => b.category === category) : all;
  if (q) items = items.filter((b) => `${b.name} ${b.family ?? ''} ${b.variant ?? ''}`.toLowerCase().includes(q));
  if (withResults) items = items.filter((b) => (num(b.result_count) ?? 0) > 0);
  const empty = all.filter((b) => (num(b.result_count) ?? 0) === 0).length;
  const totalResults = all.reduce((n, b) => n + (num(b.result_count) ?? 0), 0);
  // Family grouping: families by total results, head first, then variants by results.
  const fams = new Map<string, BenchmarkListItem[]>();
  for (const b of items) fams.set(familyOf(b), [...(fams.get(familyOf(b)) ?? []), b]);
  const famList = [...fams.entries()]
    .map(([f, list]) => ({ f, list: list.sort((a, b) => Number(!!b.attributes?.family_head) - Number(!!a.attributes?.family_head) || (num(b.result_count) ?? 0) - (num(a.result_count) ?? 0) || a.name.localeCompare(b.name)), total: list.reduce((n, b) => n + (num(b.result_count) ?? 0), 0) }))
    .sort((a, b) => b.total - a.total || a.f.localeCompare(b.f));
  const href = (patch: Record<string, string | undefined>) => {
    const p = new URLSearchParams();
    const cur = { category, q: sp.q, with_results: withResults ? '1' : undefined, ...patch };
    for (const [k, v] of Object.entries(cur)) if (v) p.set(k, v);
    const s = p.toString();
    return s ? `/benchmarks?${s}` : '/benchmarks';
  };
  const trustLevels = meth?.trust_levels ?? [];
  const filterCount = [category, q, withResults ? '1' : undefined].filter(Boolean).length;
  const ld = { '@context': 'https://schema.org', '@type': 'CollectionPage', name: 'AI benchmarks', url: `${SITE_URL}/benchmarks`, description: metadata.description, mainEntity: { '@type': 'ItemList', numberOfItems: all.length, itemListElement: all.slice(0, 12).map((b, i) => ({ '@type': 'ListItem', position: i + 1, name: b.name, url: `${SITE_URL}${routes.benchmark(b.slug)}` })) } };

  const filters = <BenchmarksFilterRail q={sp.q} category={category} withResults={withResults} total={all.length} categories={catList.map(([c, n]) => ({ c, n }))} hrefAll={href({ category: undefined })} categoryHrefs={Object.fromEntries(catList.map(([c]) => [c, href({ category: category === c ? undefined : c })]))} />;
  const inspector = (
    <div className="space-y-5 text-sm" data-benchmark-inspector>
      <dl className="kv [&>div]:grid-cols-[8rem_minmax(0,1fr)] [&>div]:py-1">
        <div>
          <dt>Benchmarks</dt>
          <dd className="tnum text-ink">{fmtInt(all.length)}</dd>
        </div>
        <div>
          <dt>Current results</dt>
          <dd className="tnum text-ink">{fmtInt(totalResults)}</dd>
        </div>
        <div>
          <dt>Without results</dt>
          <dd className="tnum text-ink">{fmtInt(empty)}</dd>
        </div>
      </dl>
      <div>
        <p className="eyebrow mb-1">Trust levels</p>
        <ul className="space-y-1">
          {(trustLevels.length ? trustLevels : Object.entries({ 'official-benchmark': 'Official benchmark leaderboard', 'independent-evaluator': 'Independent third-party evaluator', community: 'Community-run leaderboard or submission' }).map(([key, label]) => ({ key, label }))).map((t) => (
            <li key={t.key} className="flex items-start gap-2 text-xs text-ink-2">
              <TrustBadge level={t.key} /> <span>{t.label}</span>
            </li>
          ))}
        </ul>
      </div>
      <div>
        <p className="eyebrow mb-1">Comparability</p>
        <ComparabilityLegend />
      </div>
      <Note>{res?.note ?? 'Leaderboards show one row per canonical model: its best current row inside the comparability group (metric × task-defining configuration).'}</Note>
    </div>
  );

  return (
    <>
      <script type="application/ld+json" dangerouslySetInnerHTML={{ __html: JSON.stringify(ld) }} />
      <Container wide>
        <header className="flex flex-col gap-3 pb-4 pt-6 md:flex-row md:items-end md:justify-between md:pt-8">
          <div className="min-w-0">
            <p className="eyebrow">Benchmarks</p>
            <h1 className="display mt-1 text-[26px] md:text-[34px]">Benchmarks</h1>
            <p className="mt-2 max-w-2xl text-sm text-ink-2">Evaluation suites grouped by family and variant. Each leaderboard is one row per canonical model inside a comparability group; leaders are per group, never a composite.</p>
          </div>
          {res && (
            <p className="tnum text-sm text-ink-2">
              <span className="font-semibold text-ink">{fmtInt(items.length)}</span> {category ? `of ${fmtInt(all.length)} ` : ''}benchmarks · <span className="font-semibold text-ink">{fmtInt(totalResults)}</span> current results
              <Hint text="Current results = one row per model × benchmark × metric × configuration run; closed (superseded) rows are kept in history." align="right" />
            </p>
          )}
        </header>
      </Container>
      <TerminalLayout filters={filters} filterCount={filterCount} inspector={inspector} inspectorTitle="Legend" storageKey="aia-benchmarks-inspector">
        {!res ? (
          <Unavailable what="Benchmarks" />
        ) : items.length === 0 ? (
          <EmptyState title={category ? `No benchmark in “${category}”` : 'No benchmark matches'}>
            <Link href="/benchmarks" className="link">
              Show all benchmarks
            </Link>
          </EmptyState>
        ) : (
          <>
            {empty > 0 && !withResults && (
              <p className="mb-2 border-l-2 border-warning bg-warning-soft/40 px-3 py-2 text-xs text-ink-2" data-honesty>
                {fmtInt(empty)} benchmark{empty === 1 ? '' : 's'} ha{empty === 1 ? 's' : 've'} no results yet — sources being connected. They are listed so their definitions and aliases resolve; nothing is fabricated.
              </p>
            )}
            <ScrollX>
            <table className="data-table stack compact" data-benchmarks-table>
              <caption className="sr-only">Benchmarks by family</caption>
              <thead>
                <tr>
                  <th scope="col">Family · variant</th>
                  <th scope="col">Metric</th>
                  <th scope="col" className="num">
                    Results
                  </th>
                  <th scope="col" className="num">
                    Models
                  </th>
                  <th scope="col">Current leader</th>
                  <th scope="col">Updated</th>
                </tr>
              </thead>
              <tbody>
                {famList.map((fam) => (
                  <FamilyRows key={fam.f} fam={fam.f} list={fam.list} />
                ))}
              </tbody>
            </table>
            </ScrollX>
            <Note className="mt-3">Leader = best current row of the benchmark's primary comparability group (most-populated task configuration of the canonical metric), with the trust level of that row. Open a benchmark for the group picker, trust filter, frontier over time and per-model history.</Note>
          </>
        )}
      </TerminalLayout>
    </>
  );
}

function FamilyRows({ fam, list }: { fam: string; list: BenchmarkListItem[] }) {
  const grouped = list.length > 1;
  const head = list.find((b) => b.attributes?.family_head) ?? null;
  return (
    <>
      {grouped && (
        <tr className="bg-surface-2/40">
          <td colSpan={6} className="!py-1.5 text-[11px] font-semibold uppercase tracking-[0.08em] text-ink-3">
            {head?.family ?? fam} <span className="tnum font-normal normal-case tracking-normal">· {list.length} variants · {fmtInt(list.reduce((n, b) => n + (num(b.result_count) ?? 0), 0))} results</span>
          </td>
        </tr>
      )}
      {list.map((b) => {
        const empty = (num(b.result_count) ?? 0) === 0;
        const leader = b.leader;
        return (
          <tr key={b.id} className={cn(empty && 'text-ink-3')}>
            <td className={cn('primary', grouped && 'md:pl-5')}>
              <Link href={routes.benchmark(b.slug)} className="text-ink hover:text-accent hover:underline">
                {b.name}
              </Link>
              <span className="block text-[11px] text-ink-3">
                {grouped && b.variant ? `variant ${b.variant}` : b.category ?? ''}
                {grouped && b.variant && b.category ? ` · ${b.category}` : ''}
                {b.attributes?.family_head ? ' · family head' : ''}
              </span>
            </td>
            <td data-label="Metric" className="text-ink-2">
              {b.metric ?? '—'}
              <span className="text-ink-3"> {b.direction === 'lower' ? '↓ lower is better' : '↑'}</span>
              {b.groups.length > 1 && <span className="block text-[11px] text-ink-3">{fmtInt(b.groups.length)} comparability groups</span>}
            </td>
            <td data-label="Results" className="num tnum">
              {empty ? <span className="text-ink-3">0</span> : fmtInt(b.result_count)}
            </td>
            <td data-label="Models" className="num tnum text-ink-2">
              {fmtInt(b.model_count)}
            </td>
            <td data-label="Current leader">
              {leader ? (
                <span className="flex flex-wrap items-center gap-x-2 gap-y-0.5">
                  <EntityLink e={{ ...leader.model, entity_type: 'model' }} className="font-medium" />
                  <span className="tnum text-ink-2">{fmtScoreUnit(leader.score, leader.unit)}</span>
                  <TrustBadge level={leader.trust_level} label={leader.trust_label} />
                  {leader.model.organization && <span className="block w-full text-[11px] text-ink-3">{leader.model.organization.name}</span>}
                </span>
              ) : (
                <span className="text-xs text-ink-3">{empty ? 'no results yet' : '—'}</span>
              )}
            </td>
            <td data-label="Updated" className="text-xs text-ink-2" title={leader?.observed_at}>
              {leader ? fmtAgo(leader.observed_at) : '—'}
            </td>
          </tr>
        );
      })}
    </>
  );
}