/* innertube.js — YouTube search via the InnerTube JSON API (no yt-dlp spawn).
 * parseSearch() is pure (tested against fixtures/innertube-search.json);
 * search() does the HTTP call. Callers MUST fall back to yt-dlp on any throw. */
const CLIENT = { clientName: 'WEB', clientVersion: '2.20250101.00.00', hl: 'en', gl: 'US' };

export function lengthToSeconds(s) {
  if (typeof s !== 'string' || !/^\d+(:\d{1,2}){0,2}$/.test(s.trim())) return 0;
  return s.trim().split(':').map(Number).reduce((acc, n) => acc * 60 + n, 0);
}

export function parseSearch(json) {
  const sections = json?.contents?.twoColumnSearchResultsRenderer?.primaryContents
    ?.sectionListRenderer?.contents;
  if (!Array.isArray(sections)) throw new Error('innertube: unexpected response shape');
  const out = [];
  for (const s of sections) {
    for (const it of s?.itemSectionRenderer?.contents || []) {
      const v = it && it.videoRenderer;
      if (!v || typeof v.videoId !== 'string') continue;
      const owner = v.ownerText?.runs?.[0] || {};
      const be = owner.navigationEndpoint?.browseEndpoint || {};
      const path = be.canonicalBaseUrl || (be.browseId ? `/channel/${be.browseId}` : '');
      out.push({
        id: v.videoId,
        title: v.title?.runs?.map((r) => r.text).join('') || '(untitled)',
        channel: owner.text || '',
        channelId: be.browseId || '',
        channelUrl: path ? `https://www.youtube.com${path}` : '',
        duration: lengthToSeconds(v.lengthText?.simpleText),
        thumbnail: `https://i.ytimg.com/vi/${v.videoId}/mqdefault.jpg`,
      });
    }
  }
  return out;
}

export async function search(q, { fetchImpl = fetch, timeoutMs = 6000 } = {}) {
  const res = await fetchImpl('https://www.youtube.com/youtubei/v1/search?prettyPrint=false', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ context: { client: CLIENT }, query: q }),
    signal: AbortSignal.timeout(timeoutMs),
  });
  if (!res.ok) throw new Error(`innertube: HTTP ${res.status}`);
  return parseSearch(await res.json());
}