import type { APIRoute } from 'astro';
import { renderOgImage } from '../../lib/og-renderer';
import { fetchNotebookMeta } from '../../lib/server-api';
import { NOTEBOOK_ID_RE, buildNotebookDescription } from '../../lib/notebook-meta';

export const GET: APIRoute = async ({ params }) => {
  const { id } = params;

  if (!id || !NOTEBOOK_ID_RE.test(id)) {
    return new Response('Invalid notebook ID', { status: 400 });
  }

  const notebook = await fetchNotebookMeta(id);
  const title = notebook?.metadata?.title || id;
  const engine = notebook?.metadata?.engine || 'ngspice';
  const tags: string[] = notebook?.metadata?.tags || [];
  const description = buildNotebookDescription(title, engine, tags);

  try {
    const png = await renderOgImage({ title, description, engine });
    return new Response(png.buffer as ArrayBuffer, {
      headers: {
        'Content-Type': 'image/png',
        'Cache-Control': 'public, max-age=3600, s-maxage=86400',
      },
    });
  } catch (err) {
    console.error(`[og/${id}] render failed:`, err);
    return new Response('OG image generation failed', { status: 500 });
  }
};