import fs from 'node:fs/promises';

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

import type { Translations } from '~/locale/translations.ts';
import { getPosts } from '~/server/blog.ts';
import { loadSuml, loadSumlFromBase } from '~/server/loader.ts';
import { rootDir } from '~/server/paths.ts';
import parseMarkdown from '~/src/parseMarkdown.ts';
import { Translator } from '~/src/translator.ts';

const config = global.config;

const translations = loadSuml('translations') as Translations;
const baseTranslations = loadSumlFromBase('locale/_base/translations') as Translations;

const translator = new Translator(translations, baseTranslations, config);

export default defineCachedEventHandler(async () => {
    const runtimeConfig = useRuntimeConfig();

    const posts = await getPosts();

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

    for (const post of posts) {
        const markdownContent = await fs.readFile(`${rootDir}/data/blog/${post.slug}.md`, 'utf-8');
        const markdown = marked(markdownContent);
        const parsed = await parseMarkdown(markdown, translator);

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

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