server.js

const express = require('express');
const app = express();
const http = require('http');
const https = require('https');
const path = require('path');
const assert = require('assert');
const bodyParser = require('body-parser');
const fs = require('fs');
const readline = require('readline');
const rp = require('request-promise');
const cheerio = require('cheerio');
const admin = require('firebase-admin');
const dotenv = require('dotenv');
const { error } = dotenv.config();

if (error) {
  throw error;
}

admin.initializeApp({
    credential: admin.credential.cert({
        "type": process.env.FIREBASETYPE,
        "project_id": process.env.FIREBASEPROJECTID,
        "private_key_id": process.env.FIREBASEPRIVATEKEYID,
        "private_key": process.env.FIREBASEPRIVATEKEY.replace(/\\n/g, '\n'),
        "client_email": process.env.FIREBASECLIENTEMAIL,
        "client_id": process.env.FIREBASECLIENTID,
        "auth_uri": process.env.FIREBASEAUTHURI,
        "token_uri": process.env.FIREBASETOKENURI,
        "auth_provider_x509_cert_url": process.env.FIREBASE509CERTPROVIDER,
        "client_x509_cert_url": process.env.FIREBASE509CERTURL
    }),
    databaseURL: process.env.FIREBASEDATABASEURL
});

// Get a database reference to our blog
let db = admin.database();
let eventsRef = db.ref('events');


const xmlFeedUrl = 'https://www.himalayaninstitute.org/calendar/feed?action=tribe_photo&tribe_paged=1&tribe_event_display=photo&tribe_event_type%5B%5D=PureRejuv+Program&tribe_venues%5B%5D=32593&tribe_event_type%5B%5D=PureRejuv+Program&tribe_venues%5B%5D=32593';
let Parser = require('rss-parser');
let parser = new Parser();

app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
app.use('/', express.static(path.join(__dirname + '/')));

app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname + '/index.html'));
});


app.get('/parsefeed', (req, res) => {
    // https://www.npmjs.com/package/rss-parser
    /*
        {
          "creator": "Rafe Colton",
          "title": "Finding Center: An Ayurvedic Retreat to Nourish and Balance",
          "link": "https:\/\/www.himalayaninstitute.org\/event\/finding-center-ayurvedic-retreat-nourish-balance-4\/",
          "pubDate": "Fri, 14 Sep 2018 23:00:00 +0000",
          "content:encoded": "some content about the thing",
          "dc:creator": "Rafe Colton",
          "comments": "https:\/\/www.himalayaninstitute.org\/event\/finding-center-ayurvedic-retreat-nourish-balance-4\/#respond",
          "content": "<p> [&#8230;]<\/p>\n<p>The post <a rel=\"nofollow\" href=\"https:\/\/www.himalayaninstitute.org\/event\/finding-center-ayurvedic-retreat-nourish-balance-4\/\">Finding Center: An Ayurvedic Retreat to Nourish and Balance<\/a> appeared first on <a rel=\"nofollow\" href=\"https:\/\/www.himalayaninstitute.org\">Himalayan Institute<\/a>.<\/p>\n",
          "contentSnippet": "[\u2026]\nThe post Finding Center: An Ayurvedic Retreat to Nourish and Balance appeared first on Himalayan Institute.",
          "guid": "https:\/\/www.himalayaninstitute.org\/?post_type=tribe_events&p=47940",
          "isoDate": "2018-09-14T23:00:00.000Z"
        },
    */

    (async () => {

        try {
            let feed = await parser.parseURL(xmlFeedUrl);
            let allData = [];
            let index = 0;

            feed.items.forEach((item) => {
                //console.log(item.title + ':' + item.link)

                const options = {
                    uri: item.link,
                    transform: (body) => {
                        return cheerio.load(body);
                    }
                };

                rp(options)
                    .then(($) => {

                        let data = {
                            startDate : $('.tribe-event-date-start').text(),
                            endDate : $('.tribe-event-date-end').text(),
                            cost : $('.tribe-events-cost').text(),
                            title : item.title || $('#tribe-events-content h1').text(),
                            subtitle : $('.tribe-events-page-subtitle').text(),
                            contentSnippet : item.contentSnippet,
                            contentEncoded : item['content:encoded'],
                            featuredImage : $('.tribe-events-event-image img').attr('src'),
                            soldout : $('.event-sold-out').length > 0,
                            presenters : []
                        };

                        $('.presenters .presenter').each(() => {

                            let presenter = {
                                image: $(this).find('img').attr('src') || '',
                                name: $(this).find('.organizer-desc h5 a').text(),
                                description: $(this).find('.organizer-desc p').text(),
                            };

                            data.presenters.push(presenter);
                        });

                        eventsRef
                            .orderByChild('title')
                            .equalTo(data.title).on('value', (snapshot) => {
                                if (snapshot.exists()) {
                                    data.existed = true;
                                } else {
                                    eventsRef.push(data);
                                    data.existed = false;
                                }
                        });
                        
                        allData.push(data);
                    })
                    .then(() => {
                        ++index;
                        if(index === feed.items.length - 1) {
                            return res.status(200).json(allData);
                        }
                    })
                    .catch((err) => {
                        console.log(err);
                    });
            });


            //return res.status(200).json(allData);
        }
        catch(error) {
            return res.status(500).json({
                success: false,
                message: 'Unable to parse RSS feed',
                error: error
            });
        }

    })();

});


let server = app.listen(3000, () => {
    console.log('started on port 3000');
});