const fs = require('fs');

let route = fs.readFileSync('src/app/api/media/[...path]/route.ts', 'utf8');

const rangeLogic = `
    // Get file stats for Content-Length
    const stat = await fs.promises.stat(filePath);
    const fileSize = stat.size;

    // Handle Range Requests (CRITICAL for video streaming in Safari/Chrome)
    const rangeHeader = request.headers.get('range');
    let start = 0;
    let end = fileSize - 1;
    let isPartial = false;

    if (rangeHeader) {
      const parts = rangeHeader.replace(/bytes=/, '').split('-');
      const partialStart = parts[0];
      const partialEnd = parts[1];

      start = parseInt(partialStart, 10);
      end = partialEnd ? parseInt(partialEnd, 10) : fileSize - 1;
      
      if (start >= fileSize) {
        return new NextResponse('Requested range not satisfiable', { status: 416 });
      }
      isPartial = true;
    }

    const contentLength = (end - start) + 1;

    // Build response headers
    const contentType = getSafeContentType(contentTypeExt);
    const headers = new Headers();
    headers.set('Content-Type', contentType);
    headers.set('Content-Length', contentLength.toString());
    headers.set('Cache-Control', 'public, max-age=3600, stale-while-revalidate=86400');
    headers.set('Accept-Ranges', 'bytes');

    if (isPartial) {
      headers.set('Content-Range', \`bytes \${start}-\${end}/\${fileSize}\`);
    }

    // SVG: force download to prevent XSS
    if (contentType === 'image/svg+xml') {
      headers.set('Content-Disposition', \`attachment; filename="\${path.basename(relativePath)}"\`);
    }

    // Stream the file chunk
    const fileStream = fs.createReadStream(filePath, { start, end });
    const webStream = new ReadableStream({
      start(controller) {
        fileStream.on('data', (chunk) => controller.enqueue(new Uint8Array(chunk)));
        fileStream.on('end', () => controller.close());
        fileStream.on('error', (err) => controller.error(err));
      },
      cancel() {
        fileStream.destroy();
      },
    });

    return new NextResponse(webStream, { 
      status: isPartial ? 206 : 200, 
      headers 
    });
`;

route = route.replace(
  /\/\/ Get file stats for Content-Length[\s\S]+return new NextResponse\(webStream, \{ headers \}\);/,
  rangeLogic.trim()
);

fs.writeFileSync('src/app/api/media/[...path]/route.ts', route, 'utf8');