const express = require('express');
const router = express.Router();
const { Feed } = require('feed');
const contentService = require('../services/content');

function generateFeed(site) {
  const feed = new Feed({
    title: site.title,
    description: site.tagline,
    id: site.url,
    link: site.url,
    language: 'en',
    image: `${site.url}/images/og-default.png`,
    favicon: `${site.url}/favicon.ico`,
    copyright: `All rights reserved ${new Date().getFullYear()}, ${site.author ? site.author.name : site.title}`,
    author: {
      name: site.author ? site.author.name : site.title,
      link: site.url
    }
  });

  const posts = contentService.getAllPosts();

  for (const post of posts) {
    const postUrl = `${site.url}/${post.slug}`;
    feed.addItem({
      title: post.title,
      id: postUrl,
      link: postUrl,
      description: post.excerpt,
      content: post.contentHtml,
      author: [
        {
          name: post.author,
          link: site.url
        }
      ],
      date: post.date,
      image: post.cover ? (post.cover.startsWith('http') ? post.cover : `${site.url}${post.cover}`) : undefined
    });
  }

  return feed;
}

router.get(['/feed', '/rss.xml', '/feed.xml'], (req, res) => {
  const feed = generateFeed(res.locals.site);
  res.header('Content-Type', 'application/xml; charset=utf-8');
  res.send(feed.rss2());
});

router.get('/atom.xml', (req, res) => {
  const feed = generateFeed(res.locals.site);
  res.header('Content-Type', 'application/atom+xml; charset=utf-8');
  res.send(feed.atom1());
});

module.exports = router;