#!/usr/bin/env node
'use strict';

// WM: Avril pemula
// saluran : https://whatsapp.com/channel/0029VbCnMvaEgGfOncmyD02j

const fs = require('fs');
const path = require('path');
const crypto = require('crypto');

const WM = 'Avril pemula';
const CHANNEL = 'https://whatsapp.com/channel/0029VbCnMvaEgGfOncmyD02j';
const BASE_URL = 'https://snaptik.app';
const UA = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36';

const jar = new Map();

function parseSetCookie(headers) {
  const raw = headers.getSetCookie
    ? headers.getSetCookie()
    : (headers.get('set-cookie') ? [headers.get('set-cookie')] : []);
  for (const c of raw) {
    const [pair] = c.split(';');
    const i = pair.indexOf('=');
    if (i > 0) jar.set(pair.slice(0, i).trim(), pair.slice(i + 1).trim());
  }
}

const baseHeaders = () => {
  const h = {
    'User-Agent': UA,
    'Accept': 'application/json, text/plain, */*',
    'Accept-Language': 'en-US,en;q=0.9',
    'Origin': BASE_URL,
    'Referer': BASE_URL + '/'
  };
  if (jar.size) h.Cookie = [...jar].map(([k, v]) => `${k}=${v}`).join('; ');
  return h;
};

async function initSession() {
  const res = await fetch(BASE_URL + '/', { headers: baseHeaders() });
  parseSetCookie(res.headers);
}

async function fetchToken() {
  const res = await fetch(`${BASE_URL}/api/token`, {
    method: 'POST',
    headers: {
      ...baseHeaders(),
      'X-Requested-With': 'XMLHttpRequest',
      'Content-Type': 'application/json'
    }
  });
  parseSetCookie(res.headers);
  if (!res.ok) throw new Error(`token ${res.status}`);
  return res.json();
}

function decryptPuzzle(id, b64) {
  const raw = Buffer.from(b64, 'base64');
  const iv = raw.subarray(0, 16);
  const ct = raw.subarray(16);
  const key = crypto.createHash('sha256')
    .update(`sn4pt1k_v3r1fy2026:${id}`)
    .digest();
  const d = crypto.createDecipheriv('aes-256-cbc', key, iv);
  return JSON.parse(Buffer.concat([d.update(ct), d.final()]).toString('utf8'));
}

function solve(p) {
  switch (p.t) {
    case 'b': return ((p.a ^ p.b) >> p.s) & 255;
    case 'r': return p.n.reduce((x, v) => x + v, 0) * 2 + 1;
    case 'c': return p.w.charCodeAt(p.i) * p.m;
    case 'm': return ((p.a + p.b) % 100) * p.c;
    case 'n': return p.a * p.b + p.b * p.c + p.c * p.a - p.a;
    default:  throw new Error('unknown challenge ' + p.t);
  }
}

async function buildVerify() {
  const t = await fetchToken();
  const p = decryptPuzzle(t.id, t.p);
  return `${t.id}:${solve(p)}:${p._e}:${p._h}`;
}

async function extract(url, retry = true) {
  const verify = await buildVerify();
  const res = await fetch(`${BASE_URL}/api/extract?url=${encodeURIComponent(url)}`, {
    headers: {
      ...baseHeaders(),
      'X-Requested-With': 'XMLHttpRequest',
      'X-Verify': verify
    }
  });
  parseSetCookie(res.headers);
  if (res.status === 403 && retry) {
    console.log(`[${WM}] 403 → retry token baru...`);
    return extract(url, false);
  }
  if (!res.ok) throw new Error(`extract ${res.status}`);
  return res.json();
}

// ← FIX: terima downloadUrl, kirim sebagai query param &url=
async function resolveHD(hdPath, downloadUrl) {
  const verify = await buildVerify();
  let url = hdPath.startsWith('http') ? hdPath : BASE_URL + hdPath;
  if (downloadUrl) {
    url += `&url=${encodeURIComponent(downloadUrl)}`;
  }
  const res = await fetch(url, {
    headers: {
      ...baseHeaders(),
      'X-Requested-With': 'XMLHttpRequest',
      'X-Verify': verify
    }
  });
  parseSetCookie(res.headers);
  if (!res.ok) return null;
  const j = await res.json();
  return j.url || j.downloadUrl || j.hd || null;
}

async function download(url, dest) {
  const res = await fetch(url, { headers: baseHeaders() });
  if (!res.ok) throw new Error(`download ${res.status}`);
  const buf = Buffer.from(await res.arrayBuffer());
  fs.writeFileSync(dest, buf);
  return buf.length;
}

const sanitize = (s) => String(s).replace(/[^\w\-.]+/g, '_').slice(0, 80);

(async () => {
  const input = process.argv[2];
  const out = {
    watermark: WM,
    saluran: CHANNEL,
    input: input || null,
    success: false,
    type: null,
    id: null,
    title: null,
    author: null,
    stats: null,
    source: { downloadUrl: null, hdDownloadUrl: null, hdResolved: null },
    files: [],
    error: null
  };

  if (!input) {
    console.error('Usage: node snaptik.js "<url>"');
    console.log(JSON.stringify(out, null, 2));
    process.exit(1);
  }

  try {
    console.log(`[${WM}] scraping: ${input}`);
    await initSession();

    const raw = await extract(input);
    const d = raw.data || raw;

    out.id = d.id || null;
    out.title = d.title || null;
    out.author = d.author || null;
    out.stats = d.stats || null;
    out.source.downloadUrl = d.downloadUrl || null;
    out.source.hdDownloadUrl = d.hdDownloadUrl || null;

    const slide = d.type === 'image' || d.type === 'slideshow' ||
      (Array.isArray(d.images) && d.images.length > 0);
    out.type = slide ? 'image' : 'video';

    const base = sanitize(`${d.author?.username || 'tiktok'}_${d.id || Date.now()}`);
    const cwd = process.cwd();

    if (!slide) {
      let dl = d.downloadUrl;
      let q = 'SD';

      if (d.hdDownloadUrl) {
        try {
          const hd = await resolveHD(d.hdDownloadUrl, d.downloadUrl);
          if (hd) { dl = hd; q = 'HD'; out.source.hdResolved = hd; }
        } catch (e) {
          console.log(`[${WM}] HD gagal (${e.message}) → SD`);
        }
      }

      if (!dl) throw new Error('no downloadUrl');

      const f = path.join(cwd, `${base}.mp4`);
      const size = await download(dl, f);
      out.success = true;
      out.files.push({ type: 'video', quality: q, path: f, size });
      console.log(`[${WM}] ✓ ${q} → ${path.basename(f)} (${(size / 1048576).toFixed(2)} MB)`);
    } else {
      const imgs = d.images || [];
      const audio = d.music?.playUrl || d.music?.url || d.audioUrl || d.sound?.playUrl || null;

      for (let i = 0; i < imgs.length; i++) {
        const im = imgs[i];
        const u = typeof im === 'string' ? im : (im.url || im.downloadUrl || im.thumbnail);
        if (!u) continue;
        const f = path.join(cwd, `${base}_${String(i + 1).padStart(2, '0')}.jpg`);
        const size = await download(u, f);
        out.files.push({ type: 'image', index: i + 1, path: f, size });
      }

      if (audio) {
        const f = path.join(cwd, `${base}_audio.mp3`);
        const size = await download(audio, f);
        out.files.push({ type: 'audio', path: f, size });
      }

      out.success = out.files.length > 0;
      console.log(`[${WM}] ✓ slideshow → ${out.files.length} file`);
    }
  } catch (e) {
    out.error = e.message;
    console.error(`[${WM}] ✗ ${e.message}`);
  }

  console.log(JSON.stringify(out, null, 2));
  process.exit(out.success ? 0 : 1);
})();