biometrics-appointment-finder.js

const request = require('request').defaults({ jar: true});
const nodemailer = require('nodemailer');

const LOCATIONS = {
    STOCKHOLM: 'Z209',
    GÖTEBORG: 'Z102',
    MALMÖ: 'KCMA',
    TILLSTÅNDSPRÖVNING: 'BBBO',
    BORLÄNGE: 'NHL',
    JÖNKÖPING: 'Z085',
    NORRKÖPING: 'Z083',
    SUNDSVALL: 'BBSU',
    UMEÅ: 'BBUM',
    UPPSALA: 'MUP1',
    VISBY: 'Z115',
    VÄSTERÅS: 'BBVS',
    VÄXJÖ: 'BBVX',
    ÖREBRO: 'MAOM',
};
const LOCATION_NAMES = Object.keys(LOCATIONS);
const ALL_APPOINTMENTS = {};

console.log('🇸🇪💉 Info: Starting loop!');

let index = 0;
setInterval(() => {
    getAppointmentsForLocation(LOCATION_NAMES[index]);
    if (index === LOCATION_NAMES.length - 1) {
        index = 0;
        return;
    }
    index = index + 1;
}, 5000);

let hasInitialised = false;
setTimeout(() => {
    console.log('🇸🇪💉 Info: Assuming stable, will start sending emails now!');
    hasInitialised = true;
    const events = Object.keys(ALL_APPOINTMENTS).map(key => {
        ALL_APPOINTMENTS[key].key = key;
        return ALL_APPOINTMENTS[key];
    });
    console.log('🇸🇪💉 Info: Initial appointments sorted by earliest!');
    console.log(events.sort((a, b) => {
        a = new Date(a.start);
        b = new Date(b.start);
        return a < b ? -1 : a > b ? 1 : 0;
    }));
}, 120000);

const PAGE_REGEXP = /(\d+-\d+)\.IBehaviorListener/;
function getAppointmentsForLocation (location) {
    console.log(`🇸🇪💉 Getting appointments for ${location}!`);
    request(getBookingPageUrl(location), (error, _, body) => {
        if (error) {
            console.error('🇸🇪💉Error:', error);
            return;
        }

        let page;
        try {
            [, page] = body.match(PAGE_REGEXP);
        } catch {
            return;
        }
        request(getAppointmentsUrl(page), (error, _, body) => {
            if (error) {
                console.error('🇸🇪💉Error:', error);
                return;
            }
    
            const appointments = JSON.parse(body);
            appointments.forEach(appointment => {
                const key = `${location}_${appointment.id}`;
                if (!ALL_APPOINTMENTS[key]) {
                    const info = `🇸🇪💉 Available appointment in ${location} at ${new Date(appointment.start)}!`;
                    ALL_APPOINTMENTS[key] = appointment;

                    if (hasInitialised) {
                        sendEmail(info);
                    }
                }
            });
        });
    });
}

function getBookingPageUrl (location) {
    return `https://www.migrationsverket.se/ansokanbokning/valjtyp?sprak=en&bokningstyp=2&enhet=${LOCATIONS[location]}&sokande=1`;
}

function getAppointmentsUrl (page) {
    const start = new Date();
    const end = new Date();
    end.setDate(start.getDate() + 60);
    let startString = start.toISOString().substring(0, 10);
    let endString = end.toISOString().substring(0, 10);
    return `https://www.migrationsverket.se/ansokanbokning/wicket/page?${page}.IBehaviorListener.1-form-kalender-kalender&start=${startString}T00%3A00%3A00%2B00%3A00&end=${endString}T00%3A00%3A00%2B00%3A00&_=${Date.now()}`;
}

const transporter = nodemailer.createTransport({
    service: 'gmail',
    auth: {
        user: process.env.SENDER_EMAIL,
        pass: process.env.SENDER_PASSWORD
    }
});
async function sendEmail (info) {
    try {
        console.log(info);
        await transporter.sendMail({
            from: '"BIOMETRICS APPOINTMENT FINDER 💉" <biometrics@not.real>',
            to: 'craigspence0+biometrics-appointment@gmail.com',
            subject: info,
            text: info,
            html: `<b>${info}</b>`
        });
    
        console.log('🇸🇪💉 Info: Sent email');
    } catch (error) {
        console.error('🇸🇪💉 Error:', error);
    }
}