Create a Dropbox file with contents from a Twilio-forwarded SMS

twilio_dropbox_function.js

const isoFetch = require('isomorphic-fetch');
const Dropbox = require('dropbox').Dropbox;
const util = require('util');

exports.handler = function(context, event, callback) {
    log(context);
    log(event);

    const whitelisted_numbers = [
        context.HCG_NUM_1,
        context.HCG_NUM_2,
    ];

    if (!whitelisted_numbers.includes(event.From)) {
        callback(`Received text from non-whitelisted ${event.From}`);
    }

    const twilioClient = context.getTwilioClient();
    const dbx = new Dropbox({
        accessToken: context.DROPBOX_ACCESS_TOKEN,
        fetch: isoFetch,
    });
    const todoFilename = `todo_${dateFilename()}.txt`;
    const todoFilepath = `/${todoFilename}`;

    dbx.filesUpload({
        path: todoFilepath,
        contents: event.Body,
        mute: true,
        // mode: 'overwrite',
    // Upload success
    }).then(function(response) {
        console.log('dropbox upload response...');
        console.log(response);
        dbx.sharingCreateSharedLink({
            path: todoFilepath,
        // Share success
        }).then(function(response) {
            console.log('dropbox link response...');
            log(response);
            twilioClient.messages.create({
                from: event.To,
                to: event.From,
                body: `${response.url}`,
            }, twilio_err(null, callback));
        // Share fail
        }).catch(function(err) {
            console.log('dropbox link err...');
            log(err);
            twilioClient.messages.create({
                from: event.To,
                to: event.From,
                body: `❌ Dropbox link fail.\n${fmtObject(err.error)}`,
            }, twilio_err(err, callback));
        })
    // Upload fail
    }).catch(function(err) {
        console.log('dropbox upload err...');
        log(err);
        twilioClient.messages.create({
            from: event.To,
            to: event.From,
            body: `❌ Dropbox upload fail.\n${fmtObject(err.error)}`,
        }, twilio_err(err, callback));
    });
};

function twilio_err(err, callback) {
    return function(err_twilio, result) {
        if (err_twilio === null) {
            callback(err);
        } else {
            console.log('twilio err...');
            log(err_twilio);
            callback(err_twilio);
        }
    }
}

function fmtObject(obj) {
    return util.inspect(obj, {showHidden: false, depth: null});
}

function log(obj) {
    console.log(fmtObject(obj));
}

function dateFilename() {
    var dt = new Date();
    filename = `${
        dt.getFullYear().toString().padStart(4, '0')}-${
        (dt.getMonth()+1).toString().padStart(2, '0')}-${
        dt.getDate().toString().padStart(2, '0')}_${
        dt.getHours().toString().padStart(2, '0')}-${
        dt.getMinutes().toString().padStart(2, '0')}-${
        dt.getSeconds().toString().padStart(2, '0')}_${
        dt.getTime().toString()
    }`;
    return filename;
}