const fs = require("fs");
const { pipeline } = require("stream/promises");
const { Readable } = require("stream");

const BASE = "https://snapdouyin.app";
const UA = "Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/140.0.0.0 Safari/537.36";

function calculateHash(url, salt) {
  return Buffer.from(url).toString("base64") + (url.length + 1000) + Buffer.from(salt).toString("base64");
}

function parseCookies(setCookieHeaders) {
  if (!setCookieHeaders) return "";
  return setCookieHeaders.map((c) => c.split(";")[0]).join("; ");
}

async function getSessionAndToken() {
  const res = await fetch(BASE + "/", { headers: { "User-Agent": UA } });
  const html = await res.text();
  const setCookie = res.headers.getSetCookie ? res.headers.getSetCookie() : [];
  const cookie = parseCookies(setCookie);
  const match = html.match(/id="token"[^>]*value="([^"]+)"/);
  if (!match) throw new Error("Token tidak ditemukan di halaman");
  return { cookie, token: match[1] };
}

async function getVideoData(videoUrl, retries = 2) {
  for (let attempt = 0; attempt <= retries; attempt++) {
    try {
      const { cookie: initialCookie, token } = await getSessionAndToken();
      const hash = calculateHash(videoUrl, "aio-dl");

      const body = new URLSearchParams();
      body.append("url", videoUrl);
      body.append("token", token);
      body.append("hash", hash);

      const res = await fetch(BASE + "/wp-json/mx-downloader/video-data/", {
        method: "POST",
        headers: {
          "Content-Type": "application/x-www-form-urlencoded",
          Origin: BASE,
          Referer: BASE + "/",
          Cookie: initialCookie,
          "User-Agent": UA,
        },
        body,
      });

      if (!res.ok) throw new Error(`video-data gagal dengan status ${res.status}`);

      const newSetCookie = res.headers.getSetCookie ? res.headers.getSetCookie() : [];
      const newCookie = parseCookies(newSetCookie);
      const cookie = newCookie || initialCookie;

      const data = await res.json();
      if (data.error) throw new Error(data.error);
      data._cookie = cookie;
      return data;
    } catch (err) {
      if (attempt === retries) throw err;
    }
  }
}

async function downloadMedia(mediaUrl, cookie, outputPath) {
  const res = await fetch(mediaUrl + "&bandwidth_saving=1", {
    headers: {
      accept: "*/*",
      "accept-language": "id-ID,id;q=0.9,en-US;q=0.8,en;q=0.7",
      "sec-fetch-dest": "empty",
      "sec-fetch-mode": "cors",
      "sec-fetch-site": "same-origin",
      Cookie: cookie,
      "User-Agent": UA,
    },
    signal: AbortSignal.timeout(30000),
  });

  if (!res.ok) throw new Error(`download gagal dengan status ${res.status}`);
  if (!res.body) throw new Error("Response tidak punya body");

  await pipeline(Readable.fromWeb(res.body), fs.createWriteStream(outputPath));
  return outputPath;
}

async function main() {
  const url = process.argv[2];
  const qualityArg = process.argv[3];

  if (!url) {
    console.error("Gunakan: node snapdouyin.js <url_douyin> [index_kualitas]");
    process.exit(1);
  }

  const data = await getVideoData(url);

  if (qualityArg === undefined) {
    console.log(JSON.stringify(data, null, 2));
    return;
  }

  const media = data.medias[Number(qualityArg)];
  if (!media) throw new Error("Index kualitas tidak valid");

  const filename = `douyin-${media.quality.replace(/\s/g, "")}-${Date.now()}.${media.extension}`;
  await downloadMedia(media.url, data._cookie, filename);

  console.log(JSON.stringify({
    url: data.url,
    title: data.title,
    thumbnail: data.thumbnail,
    duration: data.duration,
    source: data.source,
    downloaded: {
      saved: filename,
      quality: media.quality,
      extension: media.extension,
      size: media.formattedSize,
    },
  }, null, 2));
}

main().catch((err) => {
  console.error("Error:", err.message);
  if (err.cause) console.error("Cause:", err.cause.message || err.cause);
  process.exit(1);
});