const axios = require('axios');

const HEADERS = {
  accept: 'application/json, text/javascript, */*; q=0.01',
  origin: 'https://mattw.io',
  referer: 'https://mattw.io/',
  'user-agent': 'Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36',
};

const CHANNEL_ID_REGEX = /^UC[a-zA-Z0-9_-]{22}$/;

const CHANNEL_URL_REGEX = /youtube\.com\/(?:channel\/(UC[a-zA-Z0-9_-]{22})|(?:@|user\/|c\/)([^/?&\s]+))/;

async function resolveChannelId(input) {
  const trimmed = input.trim();

  if (CHANNEL_ID_REGEX.test(trimmed)) return trimmed;

  const urlMatch = trimmed.match(CHANNEL_URL_REGEX);
  if (urlMatch && urlMatch[1]) return urlMatch[1];

  const resolveUrl = urlMatch
    ? trimmed
    : trimmed.startsWith('@')
      ? `https://youtube.com/${trimmed}`
      : `https://youtube.com/@${trimmed}`;

  const { data } = await axios.get('https://ytapi.apps.mattw.io/v1/resolve_url', {
    params: { url: resolveUrl },
    headers: HEADERS,
  });

  if (!data || !data.channelId) throw new Error('Could not resolve channel ID');
  return data.channelId;
}

async function getChannelMeta(input) {
  const channelId = await resolveChannelId(input);

  const quotaUser = Math.random().toString(36).slice(2) + Math.random().toString(36).slice(2);

  const { data } = await axios.get('https://ytapi.apps.mattw.io/v3/channels', {
    params: {
      key: 'foo1',
      quotaUser,
      part: 'id,snippet,statistics,brandingSettings,contentDetails,localizations,status,topicDetails',
      id: channelId,
      _: Date.now(),
    },
    headers: HEADERS,
  });

  if (!data.items || data.items.length === 0) throw new Error('Channel not found');

  const item = data.items[0];
  const s = item.snippet || {};
  const st = item.statistics || {};
  const bs = item.brandingSettings || {};
  const cd = item.contentDetails || {};
  const status = item.status || {};
  const topic = item.topicDetails || {};
  const thumbnails = s.thumbnails || {};
  const bestThumb = thumbnails.high || thumbnails.medium || thumbnails.default || null;

  return {
    id: item.id,
    url: `https://www.youtube.com/channel/${item.id}`,
    title: s.title || null,
    description: s.description || null,
    customUrl: s.customUrl || null,
    publishedAt: s.publishedAt || null,
    country: s.country || null,
    defaultLanguage: s.defaultLanguage || null,
    thumbnails: {
      default: thumbnails.default || null,
      medium: thumbnails.medium || null,
      high: thumbnails.high || null,
      best: bestThumb ? bestThumb.url : null,
    },
    statistics: {
      subscribers: st.subscriberCount ? parseInt(st.subscriberCount) : null,
      hiddenSubscriberCount: st.hiddenSubscriberCount ?? null,
      views: st.viewCount ? parseInt(st.viewCount) : null,
      videoCount: st.videoCount ? parseInt(st.videoCount) : null,
    },
    branding: {
      title: bs.channel?.title || null,
      description: bs.channel?.description || null,
      keywords: bs.channel?.keywords || null,
      country: bs.channel?.country || null,
      bannerExternalUrl: bs.image?.bannerExternalUrl || null,
    },
    contentDetails: {
      uploadsPlaylistId: cd.relatedPlaylists?.uploads || null,
    },
    status: {
      privacyStatus: status.privacyStatus || null,
      isLinked: status.isLinked ?? null,
      longUploadsStatus: status.longUploadsStatus || null,
      madeForKids: status.madeForKids ?? null,
    },
    topicCategories: topic.topicCategories || [],
    localizations: item.localizations || null,
  };
}

const input = process.argv[2];
if (!input) {
  process.stderr.write('Usage: node yt-channel.js <channel_url|handle|@handle|channel_id>\n');
  process.exit(1);
}

getChannelMeta(input)
  .then(r => process.stdout.write(JSON.stringify(r, null, 2) + '\n'))
  .catch(e => {
    process.stderr.write(e.message + '\n');
    process.exit(1);
  });