const axios = require("axios");

module.exports = async function handler(req, res) {
  res.setHeader("Access-Control-Allow-Origin", "*");
  res.setHeader("Access-Control-Allow-Methods", "GET, HEAD, OPTIONS");
  res.setHeader("Access-Control-Allow-Headers", "Range, Referer");

  if (req.method === "OPTIONS") return res.status(200).end();

  const { url, referer } = req.query;
  if (!url) return res.status(400).json({ success: false, message: "url query parameter is required" });

  try {
    const headers = {
      "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36",
      Referer: referer || "https://vidtube.site/",
    };

    const response = await axios.get(url, {
      headers,
      timeout: 15000,
      responseType: "arraybuffer",
      validateStatus: (s) => s < 500,
    });

    const contentType = response.headers["content-type"] || "";
    res.setHeader("Content-Type", contentType);
    res.setHeader("Cache-Control", "public, max-age=300");

    if (contentType.includes("mpegurl") || url.endsWith(".m3u8") || contentType.includes("x-mpegURL")) {
      let m3u8 = Buffer.from(response.data).toString("utf-8");
      const baseUrl = new URL(url);
      const proxyBase = "/api/proxy?url=";
      const refParam = `&referer=${encodeURIComponent(baseUrl.origin + "/")}`;

      // Rewrite absolute URLs (https://...)
      m3u8 = m3u8.replace(/^(https?:\/\/[^\s]+)$/gm, (match) => {
        return `${proxyBase}${encodeURIComponent(match)}${refParam}`;
      });

      // Rewrite relative URLs (no scheme, not tags, not comments)
      // Matches: filename.m3u8, filename.ts, path/file.m3u8, etc.
      m3u8 = m3u8.replace(/^([^\s#<][^\s]*\.(m3u8|ts|m4s|m4v|mp4|cmfv|cmfa|vtt|srt|ass|json|aac|mp3))(?:\?[^\s]*)?$/gm, (match) => {
        const absolute = new URL(match, baseUrl).href;
        return `${proxyBase}${encodeURIComponent(absolute)}${refParam}`;
      });

      res.setHeader("Content-Type", "application/vnd.apple.mpegurl");
      return res.send(m3u8);
    }

    res.send(Buffer.from(response.data));
  } catch (err) {
    res.status(500).json({ success: false, message: "Proxy failed: " + err.message });
  }
};