import { NextRequest, NextResponse } from 'next/server';
import { readFile, stat } from 'fs/promises';
import path from 'path';

const MIME_TYPES: Record<string, string> = {
  '.jpg': 'image/jpeg',
  '.jpeg': 'image/jpeg',
  '.png': 'image/png',
  '.webp': 'image/webp',
};

export async function GET(req: NextRequest, { params }: { params: Promise<{ filename: string }> }) {
  const { filename } = await params;

  if (filename.includes('/') || filename.includes('..') || filename.includes('\\')) {
    return NextResponse.json({ error: 'Ungueltiger Dateiname' }, { status: 400 });
  }

  const ext = path.extname(filename).toLowerCase();
  const mimeType = MIME_TYPES[ext];
  if (!mimeType) {
    return NextResponse.json({ error: 'Nicht unterstuetztes Dateiformat' }, { status: 400 });
  }

  const filePath = path.join(process.cwd(), 'uploads', 'sponsors', filename);

  try {
    await stat(filePath);
    const buffer = await readFile(filePath);
    return new NextResponse(buffer, {
      headers: {
        'Content-Type': mimeType,
        'Cache-Control': 'public, max-age=31536000, immutable',
      },
    });
  } catch {
    return NextResponse.json({ error: 'Bild nicht gefunden' }, { status: 404 });
  }
}