/**
 * Phase variants of a place page.
 *
 * Phase is part of the query — "primary schools in beccles", "secondary
 * schools in brentwood" — not a filter applied afterwards, so each gets its
 * own indexable path. A place with no schools of the phase has no page: the
 * per-phase threshold, not an error.
 */
import { notFound } from 'next/navigation';
import type { Metadata } from 'next';
import { fetchPlace } from '@/lib/places';
import { fetchNationalAverages } from '@/lib/api';
import { PlaceView } from '@/components/places/PlaceView';
import { absoluteUrl } from '@/lib/site';

interface Props { params: Promise<{ place: string; phase: string }> }

export const revalidate = 604800;
export const dynamicParams = true;

const PHASES = ['primary', 'secondary'] as const;
type Phase = (typeof PHASES)[number];

const isPhase = (v: string): v is Phase => (PHASES as readonly string[]).includes(v);

async function resolve(slug: string, phase: Phase) {
  return (await fetchPlace('town', slug, phase))
    ?? (await fetchPlace('locality', slug, phase));
}

export async function generateMetadata({ params }: Props): Promise<Metadata> {
  const { place: slug, phase } = await params;
  if (!isPhase(phase)) return { title: 'Place Not Found' };
  const detail = await resolve(slug, phase);
  if (!detail || detail.schools.length === 0) return { title: 'Place Not Found' };

  const word = phase === 'secondary' ? 'Secondary' : 'Primary';
  const { name } = detail.place;
  return {
    // Not "Ranked": the table is alphabetical, so the word would be a claim
    // the page does not keep.
    title: { absolute: `${word} Schools in ${name} | schoolcompare` },
    description:
      `Every ${phase} school in ${name}, with results, Ofsted grades and the local `
      + `average against England.`,
    alternates: { canonical: absoluteUrl(`/schools/${slug}/${phase}`) },
  };
}

export default async function PlacePhasePage({ params }: Props) {
  const { place: slug, phase } = await params;
  if (!isPhase(phase)) notFound();
  const detail = await resolve(slug, phase);
  if (!detail || detail.schools.length === 0) notFound();

  const national = await fetchNationalAverages().catch(() => null);
  const englandAverage = phase === 'secondary'
    ? national?.secondary?.attainment_8_score ?? null
    : national?.primary?.rwm_expected_pct ?? null;

  return <PlaceView detail={detail} phase={phase}
    englandAverage={englandAverage} neighbours={[]} />;
}