import { ImageResponse } from 'next/og';
import { getPostBySlug } from '@/lib/blog';
import { OGImageTemplate } from '@/components/OGImageTemplate';
import { getOgFonts, OG_IMAGE_SIZE } from '@/lib/og-helper';
import { SITE_URL } from '@/lib/schema';

export const size = OG_IMAGE_SIZE;
export const contentType = 'image/png';
export const runtime = 'nodejs';

async function fetchImageAsBase64(url: string) {
  try {
    const res = await fetch(url);
    if (!res.ok) return undefined;
    const arrayBuffer = await res.arrayBuffer();
    const buffer = Buffer.from(arrayBuffer);
    const contentType = res.headers.get('content-type') || 'image/jpeg';
    return `data:${contentType};base64,${buffer.toString('base64')}`;
  } catch (error) {
    console.error('Failed to fetch OG image:', url, error);
    return undefined;
  }
}

export default async function Image({
  params,
}: {
  params: Promise<{ locale: string; slug: string }>;
}) {
  const { locale, slug } = await params;
  const post = await getPostBySlug(slug, locale);

  if (!post) {
    return new Response('Post not found', { status: 404 });
  }

  const fonts = await getOgFonts();

  // We don't have request.url here, but we can assume the domain from SITE_URL or config
  // For local images during dev, relative paths in <img> might not work in Satori
  // but if we are in nodejs runtime, we could potentially read from disk.
  // For now, let's just make sure it's absolute.
  const featuredImage = post.frontmatter.featuredImage
    ? post.frontmatter.featuredImage.startsWith('http')
      ? post.frontmatter.featuredImage
      : `${SITE_URL}${post.frontmatter.featuredImage}`
    : undefined;

  // Fetch image explicitly and convert to base64 because Satori sometimes struggles
  // fetching remote URLs directly inside ImageResponse correctly in various environments.
  let base64Image: string | undefined = undefined;
  if (featuredImage) {
    base64Image = await fetchImageAsBase64(featuredImage);
  }

  return new ImageResponse(
    <OGImageTemplate
      title={post.frontmatter.title}
      description={post.frontmatter.excerpt}
      label={post.frontmatter.category || 'Blog'}
      image={base64Image || featuredImage}
    />,
    {
      ...OG_IMAGE_SIZE,
      fonts,
    },
  );
}