/**
 * Weibo Scraper + Downloader (ESM)
 *
 * Usage:
 *   node weibo.js "https://weibo.com/xxx/xxx"
 *   node weibo.js "https://weibo.com/xxx/xxx" --download
 */

import { mkdir } from 'node:fs/promises';
import { join } from 'node:path';
import { createWriteStream } from 'node:fs';
import { pipeline } from 'node:stream/promises';
import { Readable } from 'node:stream';

const UA =
  'Mozilla/5.0 (iPhone; CPU iPhone OS 17_0 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/17.0 Mobile/15E148 Safari/604.1';

const HEADERS = {
  'User-Agent': UA,
  Accept: 'application/json, text/plain, */*',
  Referer: 'https://m.weibo.cn/',
  'X-Requested-With': 'XMLHttpRequest',
  'MWeibo-Pwa': '1',
};

const BASE62 = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';

function base62Decode(str) {
  let num = 0n;
  for (const c of str) {
    num = num * 62n + BigInt(BASE62.indexOf(c));
  }
  return num.toString();
}

function midToId(mid) {
  if (/^\d+$/.test(mid)) return mid;
  let result = '';
  for (let i = mid.length; i > 0; i -= 4) {
    const start = Math.max(0, i - 4);
    let num = base62Decode(mid.slice(start, i));
    if (start > 0) num = num.padStart(7, '0');
    result = num + result;
  }
  return result.replace(/^0+/, '') || '0';
}

function parseWeiboUrl(url) {
  url = url.trim();
  if (url.includes('t.cn/')) return { type: 'short', shortUrl: url };

  let m = url.match(/weibo\.com\/(?:u\/)?(\d+)\/([A-Za-z0-9]+)/);
  if (m) return { uid: m[1], mid: m[2], id: midToId(m[2]) };

  m = url.match(/weibo\.com\/(?:detail|status)\/(\d+)/);
  if (m) return { id: m[1] };

  m = url.match(/m\.weibo\.cn\/(?:detail|status)\/([A-Za-z0-9]+)/);
  if (m) {
    const v = m[1];
    return /^\d+$/.test(v) ? { id: v } : { mid: v, id: midToId(v) };
  }

  m = url.match(/m\.weibo\.cn\/(\d+)\/([A-Za-z0-9]+)/);
  if (m) return { uid: m[1], mid: m[2], id: midToId(m[2]) };

  if (/^[A-Za-z0-9]{8,12}$/.test(url)) return { mid: url, id: midToId(url) };
  if (/^\d{15,20}$/.test(url)) return { id: url };

  throw new Error('URL tidak dikenali');
}

async function resolveShortUrl(shortUrl) {
  const res = await fetch(shortUrl, {
    method: 'HEAD',
    redirect: 'manual',
    headers: { 'User-Agent': UA },
  });
  const loc = res.headers.get('location');
  if (!loc) throw new Error('Gagal resolve short link');
  return loc;
}

async function fetchStatus(idOrMid, cookie = '') {
  const id = /^\d+$/.test(idOrMid) ? idOrMid : midToId(idOrMid);
  const headers = { ...HEADERS };
  if (cookie) headers.Cookie = cookie;

  const res = await fetch(`https://m.weibo.cn/statuses/show?id=${id}`, { headers });
  if (!res.ok) throw new Error(`HTTP ${res.status}`);
  const json = await res.json();
  if (json.ok !== 1) throw new Error(json.msg || 'Gagal ambil data');
  return json.data;
}

function extractMedia(data) {
  const medias = [];

  if (data.pics?.length) {
    for (const pic of data.pics) {
      const url = pic.large?.url || pic.url;
      medias.push({
        type: 'image',
        url: url?.replace(/\/orj\d+\//, '/large/') || url,
        thumbnail: pic.url,
        livePhoto: pic.videoSrc || null,
      });
    }
  }

  if (data.pic_infos) {
    for (const info of Object.values(data.pic_infos)) {
      const largest = info.largest || info.original || info.large || info.mw2000;
      medias.push({
        type: 'image',
        url: largest?.url,
        thumbnail: info.thumbnail?.url,
        livePhoto: info.video_src || null,
      });
    }
  }

  const pi = data.page_info;
  if (pi?.type === 'video' || pi?.media_info) {
    const mi = pi.media_info || {};
    const urls = pi.urls || {};
    const list = [];

    if (urls.mp4_720p_mp4) list.push({ quality: '720p', url: urls.mp4_720p_mp4 });
    if (urls.mp4_hd_mp4 || mi.stream_url_hd) {
      list.push({ quality: 'HD', url: urls.mp4_hd_mp4 || mi.stream_url_hd });
    }
    if (urls.mp4_ld_mp4 || mi.stream_url) {
      list.push({ quality: 'LD', url: urls.mp4_ld_mp4 || mi.stream_url });
    }

    if (mi.playback_list) {
      for (const item of mi.playback_list) {
        if (item.play_info?.url) {
          list.push({
            quality: item.meta?.quality_desc || item.meta?.label || 'unknown',
            url: item.play_info.url,
          });
        }
      }
    }

    const seen = new Set();
    const unique = list.filter((q) => {
      if (seen.has(q.url)) return false;
      seen.add(q.url);
      return true;
    });

    if (unique.length) {
      medias.push({
        type: 'video',
        url: unique[0].url,
        quality: unique[0].quality,
        allQualities: unique,
        duration: mi.duration,
        cover: pi.page_pic?.url,
        title: pi.content1 || pi.page_title,
        playCount: pi.play_count,
      });
    }
  }

  return medias;
}

function parseMetadata(data) {
  const u = data.user || {};
  const profileUrl = u.profile_url
    ? u.profile_url.startsWith('http')
      ? u.profile_url
      : `https://weibo.com${u.profile_url}`
    : null;

  return {
    id: data.id || data.mid,
    mid: data.bid || data.mblogid,
    text: (data.text || '').replace(/<[^>]+>/g, '').trim(),
    createdAt: data.created_at,
    source: (data.source || '').replace(/<[^>]+>/g, ''),
    region: data.region_name,
    reposts: data.reposts_count,
    comments: data.comments_count,
    attitudes: data.attitudes_count,
    user: {
      id: u.id,
      screenName: u.screen_name,
      profileUrl,
      avatar: u.avatar_hd || u.profile_image_url,
      verified: u.verified,
      verifiedReason: u.verified_reason,
      followers: u.followers_count_str || u.followers_count,
      description: u.description,
    },
    medias: extractMedia(data),
  };
}

async function downloadFile(url, destPath, cookie = '') {
  const headers = {
    'User-Agent': UA,
    Accept: '*/*',
    Referer: 'https://weibo.com/',
    Origin: 'https://weibo.com',
  };
  if (cookie) headers.Cookie = cookie;

  let res = await fetch(url, { headers, redirect: 'follow' });

  if (!res.ok) {
    headers.Referer = 'https://m.weibo.cn/';
    headers.Origin = 'https://m.weibo.cn';
    res = await fetch(url, { headers, redirect: 'follow' });
    if (!res.ok) throw new Error(`HTTP ${res.status}`);
  }

  await mkdir(join(destPath, '..'), { recursive: true });
  await pipeline(Readable.fromWeb(res.body), createWriteStream(destPath));
  return destPath;
}

async function scrapeWeibo(url, options = {}) {
  const { cookie = '', download = false, outDir = './weibo_download' } = options;

  let parsed = parseWeiboUrl(url);
  if (parsed.type === 'short') {
    const resolved = await resolveShortUrl(parsed.shortUrl);
    parsed = parseWeiboUrl(resolved);
  }

  const data = await fetchStatus(parsed.id || parsed.mid, cookie);
  const meta = parseMetadata(data);

  if (download && meta.medias.length) {
    await mkdir(outDir, { recursive: true });

    const safeName = (meta.user.screenName || 'user').replace(/[\/\\?%*:|"<>]/g, '_');
    const base = `${safeName}_${meta.id}`;

    for (let i = 0; i < meta.medias.length; i++) {
      const m = meta.medias[i];
      if (!m.url) continue;

      const candidates = m.allQualities?.length
        ? m.allQualities.map((q) => q.url)
        : [m.url];

      const ext = m.type === 'video' ? 'mp4' : 'jpg';
      const index = String(i + 1).padStart(2, '0');
      const filename = `${base}_${index}.${ext}`;
      const dest = join(outDir, filename);

      let success = false;
      for (const cand of candidates) {
        try {
          await downloadFile(cand, dest, cookie);
          m.localPath = dest;
          m.url = cand;
          console.log(`✓ ${filename}`);
          success = true;
          break;
        } catch (e) {
          console.warn(`  gagal kualitas, coba berikutnya... (${e.message})`);
        }
      }
      if (!success) console.error(`✗ Gagal download media #${i + 1}`);
    }
  }

  return meta;
}

// CLI
const url = process.argv[2];
if (!url) {
  console.error('Usage: node weibo.js <url> [--download]');
  process.exit(1);
}

scrapeWeibo(url, {
  download: process.argv.includes('--download'),
})
  .then((meta) => console.log(JSON.stringify(meta, null, 2)))
  .catch((err) => {
    console.error('Error:', err.message);
    process.exit(1);
  });