import { getCollection, render } from "astro:content";
import { SITE } from "@/config";
import mdxRenderer from "@astrojs/mdx/server.js";
import reactRenderer from "@astrojs/react/server.js";
import rss, { type RSSFeedItem } from "@astrojs/rss";
import type { APIContext } from "astro";
import { experimental_AstroContainer as AstroContainer } from "astro/container";
import sanitizeHtml from "sanitize-html";
export async function GET(context: APIContext) {
  // Get the URL to prepend to relative site links. Based on `site` in `astro.config.mjs`.
  let baseUrl = context.site?.href || "https://*****.de";
  if (baseUrl.at(-1) === "/") baseUrl = baseUrl.slice(0, -1);
  // Create a new Astro container that we can render components with.
  // See https://docs.astro.build/en/reference/container-reference/
  const container = await AstroContainer.create();
  // Load MDX and React renderer.
  // Other renderers for UI frameworks (e.g. Vue, etc.) would need adding here if you were using those.
  container.addServerRenderer({
    renderer: mdxRenderer,
  });
  container.addServerRenderer({
    renderer: reactRenderer,
  });
  container.addClientRenderer({
    name: "@astrojs/react",
    entrypoint: "@astrojs/react/client.js",
  });
  // Load the published posts to add to our RSS feed.
  const posts = (
    await getCollection("posts", ({ data }) => Boolean(data.published))
  ).sort((a, b) =>
    // Satisfy TypeScript by checking for `undefined` first.
    !a.data.published || !b.data.published
      ? -1 // Sort by published date, descending.
      : b.data.published > a.data.published
        ? 1
        : -1,
  );
  // Loop over blog posts to create feed items for each, including full content.
  const feedItems: RSSFeedItem[] = await Promise.all(
    posts.map(async (post) => {
      const feedItem: RSSFeedItem = {
        title: post.data.title,
        description: post.data.description,
        pubDate: post.data.published,
        link: `/posts/${post.id}/`,
      };
      // Get the `<Content/>` component for the current post.
      const { Content } = await render(post);
      // Use the Astro container to render the content to a string.
      const postHtml = await container.renderToString(Content);
      // Process and sanitize the raw content with sanitize-html.
      // Also make sure that relative links are converted to absolute links.
      const sanitizedHtml = sanitizeHtml(postHtml, {
        allowedTags: [...sanitizeHtml.defaults.allowedTags, "img"],
        transformTags: {
          a: (tagName, attribs) => ({
            tagName,
            attribs: {
              ...attribs,
              ...(attribs.href && {
                href: attribs.href.startsWith("/")
                  ? baseUrl + attribs.href
                  : attribs.href,
              }),
            },
          }),
          img: (tagName, attribs) => ({
            tagName,
            attribs: {
              ...attribs,
              ...(attribs.src && {
                src: attribs.src.startsWith("/")
                  ? baseUrl + attribs.src
                  : attribs.src,
              }),
              ...(attribs.href && {
                href: attribs.href.startsWith("/")
                  ? baseUrl + attribs.href
                  : attribs.href,
              }),
            },
          }),
        },
      });
      feedItem.content = sanitizedHtml;
      return feedItem;
    }),
  );
  return rss({
    title: SITE.title,
    description: SITE.description,
    site: baseUrl,
    items: feedItems,
    customData: "<language>en-us</language>",
    stylesheet: "/assets/styles/rss.xsl",
  });
}