#!/usr/bin/env node
/**
 * fetch-anime-art.mjs
 * ---------------------------------------------------------------------------
 * Support tool for the Anime page. For each favorite item (those with
 * `favorite: true`) in src/data/media/anime.json that is missing an `image`,
 * it queries the AniList GraphQL API (free, no key required) and downloads the
 * cover to public/images/anime/<slug>.jpg, then writes the local public path
 * back into the JSON.
 *
 * AniList is chosen over Jikan (MyAnimeList) because Jikan's public API is
 * being discontinued on October 1, 2026. AniList is keyless and stable.
 *
 * Idempotent: items that already have an `image` are skipped. Be polite —
 * there's a small delay between requests.
 *
 * USAGE
 *   node scripts/fetch-anime-art.mjs               # fetch missing anime covers
 *   node scripts/fetch-anime-art.mjs --force       # re-fetch even if image set
 *   node scripts/fetch-anime-art.mjs --sleep 500   # ms between requests
 *   node scripts/fetch-anime-art.mjs --help
 */
import { mkdir, readFile, writeFile } from 'node:fs/promises';
import { dirname, join, resolve } from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = dirname(fileURLToPath(import.meta.url));
const PROJECT_ROOT = resolve(__dirname, '..');
const DATA_FILE = join(PROJECT_ROOT, 'src', 'data', 'media', 'anime.json');
const OUT_DIR = join(PROJECT_ROOT, 'public', 'images', 'anime');
const PUBLIC_PREFIX = '/images/anime';

const ANILIST_API = 'https://graphql.anilist.co';

// --- args -------------------------------------------------------------------
const args = process.argv.slice(2);
if (args.includes('-h') || args.includes('--help')) {
  console.log(`Usage: node scripts/fetch-anime-art.mjs [options]

Reads anime.json favorites and fills in the "image" field for any favorite
missing one, using the AniList GraphQL API (free, no key required).

Options:
  --force        re-fetch even for items that already have an image
  --sleep <ms>   delay between AniList requests (default 500)
  -h, --help     show this help`);
  process.exit(0);
}

const force = args.includes('--force');
const sleepIdx = args.indexOf('--sleep');
const sleepMs = sleepIdx !== -1 ? Number(args[sleepIdx + 1]) || 500 : 500;

// --- helpers ----------------------------------------------------------------
const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

const slugify = (s) =>
  s
    .toLowerCase()
    .replace(/['’.:()]/g, '')
    .replace(/[^a-z0-9]+/g, '-')
    .replace(/^-+|-+$/g, '');

const QUERY = `
  query ($search: String) {
    Page(page: 1, perPage: 5) {
      media(search: $search, type: ANIME, sort: SEARCH_MATCH) {
        title { romaji english }
        coverImage { large extraLarge }
      }
    }
  }
`;

/** Query AniList for a title, returning the best match's cover URL. */
async function fetchCover(title) {
  const res = await fetch(ANILIST_API, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json', Accept: 'application/json' },
    body: JSON.stringify({ query: QUERY, variables: { search: title } }),
  });
  if (res.status === 429) {
    console.warn('  ! rate-limited by AniList (429). Wait and re-run; skipping rest.');
    return { rateLimited: true };
  }
  if (!res.ok) throw new Error(`AniList ${res.status} ${res.statusText}`);
  const { data, errors } = await res.json();
  if (errors?.length) throw new Error(errors[0].message);
  const media = data?.Page?.media?.find((m) => m.coverImage?.large) ?? data?.Page?.media?.[0];
  if (!media?.coverImage) return null;
  const url = media.coverImage.extraLarge ?? media.coverImage.large;
  const name = media.title?.english ?? media.title?.romaji ?? title;
  return { url, name };
}

// --- main -------------------------------------------------------------------
let items;
try {
  items = JSON.parse(await readFile(DATA_FILE, 'utf8'));
} catch (err) {
  if (err?.code === 'ENOENT') {
    console.error(`✖ ${DATA_FILE} not found.`);
    process.exit(1);
  }
  throw err;
}

const favorites = items.filter((i) => i.favorite);
console.log(
  `→ ${favorites.length} anime favorite(s) in anime.json` +
    (force ? ' (force re-fetch)' : ''),
);

await mkdir(OUT_DIR, { recursive: true });
let changed = false;

for (let i = 0; i < favorites.length; i++) {
  const item = favorites[i];
  if (item.image && !force) {
    console.log(`  ✓ ${item.title} — already has image, skipping.`);
    continue;
  }
  if (i > 0) await sleep(sleepMs);

  console.log(`→ [${i + 1}/${favorites.length}] ${item.title}`);
  let result;
  try {
    result = await fetchCover(item.title);
  } catch (err) {
    console.warn(`  ! network error: ${err?.message ?? err}; skipping.`);
    continue;
  }
  if (result?.rateLimited) break;
  if (!result?.url) {
    console.warn(`  ! no cover found for "${item.title}"; skipping.`);
    continue;
  }

  const fileName = `${slugify(item.title)}.jpg`;
  let buf;
  try {
    const imgRes = await fetch(result.url);
    if (!imgRes.ok) throw new Error(`${imgRes.status} ${imgRes.statusText}`);
    buf = Buffer.from(await imgRes.arrayBuffer());
  } catch (err) {
    console.warn(`  ! image download failed (${err?.message ?? err}); skipping.`);
    continue;
  }
  await writeFile(join(OUT_DIR, fileName), buf);
  item.image = `${PUBLIC_PREFIX}/${fileName}`;
  const orig = items.find((o) => o.title === item.title && o.favorite);
  if (orig) orig.image = item.image;
  changed = true;
  console.log(`  ✔ ${item.title} → ${item.image}`);
}

if (changed) {
  await writeFile(DATA_FILE, JSON.stringify(items, null, 2) + '\n', 'utf8');
  console.log(`\n✔ Updated ${DATA_FILE}`);
} else {
  console.log('\n— Nothing to update (all anime favorites already had images).');
}