Proxy everything

gistfile1.txt

// Adjust proxy server to rewrite URLs
// Main proxy route that handles all incoming requests
// Takes a URL parameter that specifies which resource to proxy
app.get("/proxy/:url", async (req, res) => {
  // Decode the URL parameter since it comes URL-encoded
  const url = decodeURIComponent(req.params.url);
  // Create URL object to help with resolving relative URLs later
  const baseUrl = new URL(url);

  try {
    // Fetch the target URL content as a raw buffer to handle different content types
    const response = await axios.get(url, { responseType: "arraybuffer" });
    const contentType = response.headers["content-type"];

    // Forward the original content type header to maintain proper content handling
    if (contentType) {
      res.setHeader("Content-Type", contentType);
    }

    let html = response.data;

    // Special handling for HTML content to modify internal resources
    if (contentType && contentType.includes("text/html")) {
      // Convert buffer to string for HTML processing
      html = Buffer.from(html, "binary").toString();

      // Parse HTML with Cheerio (jQuery-like API for server-side)
      const $ = cheerio.load(html);

      // Process all stylesheet links to proxy them through our server
      // This ensures CSS files are also fetched through our proxy
      $('link[rel="stylesheet"]').each((_, element) => {
        const href = $(element).attr("href");
        if (href) {
          // Convert relative URLs to absolute using the base URL
          const absoluteUrl = new URL(href, baseUrl.origin);
          // Rewrite href to go through our proxy
          $(element).attr(
            "href",
            `${req.protocol}://${req.get("host")}/proxy/${encodeURIComponent(
              absoluteUrl.href
            )}`
          );
        }
      });

      // Process all images to proxy them through our server
      // Similar to stylesheet processing
      $("img").each((_, element) => {
        const src = $(element).attr("src");
        if (src) {
          const absoluteUrl = new URL(src, baseUrl.origin);
          $(element).attr(
            "src",
            `${req.protocol}://${req.get("host")}/proxy/${encodeURIComponent(
              absoluteUrl.href
            )}`
          );
        }
      });

      // Remove autoplay attributes from video elements
      // This prevents unwanted automatic video playback
      $("video[autoplay]").removeAttr("autoplay");
      $('video[playsinline]').removeAttr('playsinline'); 

      // Handle iframe elements, particularly for video embeds
      // Modify their URLs to disable autoplay functionality
      $("iframe").each((_, element) => {
        const src = $(element).attr("src");
        if (src) {
          // Special handling for YouTube and Vimeo iframes
          if (src.includes("youtube.com") || src.includes("vimeo.com")) {
            const separator = src.includes("?") ? "&" : "?";
            const newSrc = `${src}${separator}autoplay=0`;
            $(element).attr("src", newSrc);
          }
        }
      });

      // Handle base tags and links
      // Remove base tags as they can interfere with our URL rewriting
      $("base").remove();
      // Process all anchor tags to proxy their destinations
      $("a").each((_, element) => {
        const href = $(element).attr("href");
        if (href) {
          const absoluteUrl = new URL(href, baseUrl.origin);
          $(element)
            .attr(
              "href",
              `${req.protocol}://${req.get("host")}/proxy/${encodeURIComponent(
                absoluteUrl.href
              )}`
            )
            // Force links to open in the same window to maintain proxy context
            .attr("target", "_self");
        }
      });

      // Inject JavaScript to handle client-side behavior
      // This script ensures proper link handling and video control
      $("body").append(`<script>
                // Intercept clicks on proxied links to handle them properly
                document.addEventListener('click', (evt) => {
                    const target = evt.target;
                    if (target && target.getAttribute('href')?.startsWith('/proxy/')) {
                        evt.preventDefault();
                        window.location.href = target.getAttribute('href');
                    }
                });
                // Ensure all videos are paused when the page loads
                document.addEventListener('DOMContentLoaded', function() {
                    const videos = document.querySelectorAll('video');
                    videos.forEach(video => {
                        video.pause(); // Ensure videos are paused
                    });
                });
            </script>`);

      // Send the modified HTML back to the client
      res.send($.html());
    } else {
      // For non-HTML content (CSS, images, etc.), send the raw buffer
      res.send(response.data);
    }
  } catch (error) {
    // Log any errors and send an error response
    console.error("Error fetching content", error);
    res.status(500).send("Error fetching content");
  }
});