import { Feed } from 'feed';
import marked from 'marked';

import { getPosts } from '~/server/blog.ts';
import { getLocale, loadConfig, loadTranslator } from '~/server/data.ts';
import { getUrlForLocale } from '~/src/domain.ts';
import parseMarkdown from '~/src/parseMarkdown.ts';

export default defineCachedEventHandler(async (event) => {
    const locale = getLocale(event);
    const [config, translator] = await Promise.all([loadConfig(locale), loadTranslator(locale)]);

    const baseUrl = getUrlForLocale(locale);
    const posts = await getPosts(config);

    const feed = new Feed({
        title: `${translator.translate('title')} • ${translator.translate('links.blog')}`,
        description: translator.translate('description'),
        id: baseUrl,
        link: `${baseUrl}/blog.atom`,
        language: config.locale,
        image: `${baseUrl}/icon.png`,
        favicon: `${baseUrl}/icon.png`,
        updated: new Date(posts[0].date),
        copyright: '',
    });

    for (const post of posts) {
        const markdown = marked(post.content);
        const parsed = await parseMarkdown(markdown, translator);

        feed.addItem({
            title: post.title,
            id: `${baseUrl}/${config.links.blogRoute}/${post.slug}`,
            link: `${baseUrl}/${config.links.blogRoute}/${post.slug}`,
            description: parsed.intro ?? undefined,
            content: parsed.content ?? undefined,
            author: post.authors.map((author) => ({
                name: author,
                link: author.startsWith('@') ? `${baseUrl}/${author}` : undefined,
            })),
            date: new Date(post.date),
            image: post.hero ? `${baseUrl}${post.hero.src}` : undefined,
        });
    }

    return new Response(feed.atom1(), {
        headers: {
            'Content-Type': 'application/rss+xml; charset=utf-8',
        },
    });
}, {
    // TODO key
    maxAge: Infinity,
});