app/api/image-proxy/route.ts

/*
 * route.ts
 * Purpose: Fetches remote images through a same-origin route so export/canvas code can safely reuse them.
 * Used by: Image capture/export helpers and any UI path that needs proxied remote images.
 * Depends on: Next.js route handlers and remote fetch.
 */

import { NextRequest, NextResponse } from 'next/server';

export async function GET(request: NextRequest) {
  const rawUrl = request.nextUrl.searchParams.get('url');

  if (!rawUrl) {
    return NextResponse.json({ error: 'url required' }, { status: 400 });
  }

  let target: URL;
  try {
    target = new URL(rawUrl);
  } catch {
    return NextResponse.json({ error: 'invalid url' }, { status: 400 });
  }

  if (!['http:', 'https:'].includes(target.protocol)) {
    return NextResponse.json({ error: 'unsupported protocol' }, { status: 400 });
  }

  try {
    const response = await fetch(target.toString(), {
      headers: {
        'User-Agent': 'powerpoint-image-proxy/1.0',
      },
      cache: 'no-store',
    });

    if (!response.ok) {
      return NextResponse.json({ error: 'failed to fetch asset' }, { status: response.status });
    }

    const contentType = response.headers.get('content-type') || 'application/octet-stream';
    const buffer = await response.arrayBuffer();

    return new NextResponse(buffer, {
      status: 200,
      headers: {
        'Content-Type': contentType,
        'Cache-Control': 'public, max-age=3600',
      },
    });
  } catch (error) {
    console.error('Image proxy error:', error);
    return NextResponse.json({ error: 'failed to proxy asset' }, { status: 502 });
  }
}