const {
    Feed
} = require("feed");
const fs = require("fs");
const showdown = require("showdown");
const converter = new showdown.Converter({
    parseImgDimensions: true
});

module.exports = function (app) {
    app.get('/rss.xml', function (_req, res) {
        createFeed(function (feed) {
            res.header('Content-Type', 'application/xml');
            res.send(feed.rss2());
        });
    });
    app.get('/feed.json', function (_req, res) {
        createFeed(function (feed) {
            res.header('Content-Type', 'application/json');
            res.send(feed.json1());
        });
    });
    app.get('/atom.xml', function (_req, res) {
        createFeed(function (feed) {
            res.header('Content-Type', 'application/xml');
            res.send(feed.atom1());
        });
    })
}

function createFeed(callback) {
    const feed = new Feed({
        title: "Ellpeck's Blog",
        description: "Occasionally I enjoy writing stuff. So here's some of the stuff I've written about gaming, programming and life.",
        id: "https://ellpeck.de",
        link: "https://ellpeck.de",
        image: "https://ellpeck.de/res/logo.png",
        favicon: "https://ellpeck.de/favicon.ico",
        feedLinks: {
            json: "https://ellpeck.de/feed.json",
            atom: "https://ellpeck.de/atom.xml"
        },
        author: {
            name: "Ellpeck",
            email: "me@ellpeck.de",
            link: "https://ellpeck.de"
        }
    });

    fs.readFile(__dirname + "/../blog/posts.json", function (_, data) {
        let json = JSON.parse(data);
        for (let i = json.length - 1; i >= 0; i--) {
            let post = json[i];
            let id = post["id"];
            let date = new Date(post["date"]);

            fs.readFile(__dirname + "/../blog/" + id + ".md", function (_, content) {
                let html = converter.makeHtml(content.toString());
                feed.addItem({
                    title: post["name"],
                    link: "https://ellpeck.de/#blog-" + id,
                    description: post["summary"],
                    content: html,
                    date: date,
                    published: date
                });

                if (i == 0) {
                    callback(feed);
                }
            });
        }
    });
}