A Twilio Function that checks your calendar and either forwards your calls to your mobile number or records a voicemail

receiveCall.js

exports.handler = function(context, event, callback) {
    
    const moment = require('moment');

    const { google } = require('googleapis');
    const cal = google.calendar({
        version: 'v3',
        auth: context.GoogleAPIKEY
    });

    let calendar = context.myGoogleCalendar;
    let now = moment();
    let tenMinutesFromNow = moment().add(10,'minutes');


    // Make the query
    return cal.freebusy.query({
        resource: {
            // Set times to ISO strings as such
            timeMin: now.toISOString(), 
            timeMax: tenMinutesFromNow.toISOString(),
            items: [{ id: calendar }]
        }
    }).then((result) => {
        const busy = result.data.calendars[calendar].busy;
        const errors = result.data.calendars[calendar].errors;
        if (busy.length !== 0) {
            // Respond and Prompt for recording
            let twiml = new Twilio.twiml.VoiceResponse();
            twiml.say("Nathaniel is unavailable right now. If you leave a message he will get back to you as soon as possible.");
            twiml.record({
                timeout: 10,
                recordingStatusCallback: '/voicemail',
                recordingStatusCallbackEvent: 'completed'
            });
        	callback(null, twiml);
        } else {
            //   Forward to mobile
            let twiml = new Twilio.twiml.VoiceResponse();
	          twiml.dial(context.MobileNumber);
	          callback(null, twiml);
        }
    }).catch((e) => {
        console.error(e);
    }); 
};