airtable_update.js

/* global module, exports, require, process, console */
'use strict'

const Airtable = require('airtable')

// Configure Airtable database
const base = new Airtable({
  apiKey: process.env.AIRTABLE_API_KEY}
).base(process.env.AIRTABLE_DATABASE)

// Get handle to Contacts tab of database
const contacts = base(process.env.AIRTABLE_CONTACTS_TAB)

// Helper to create a field update object based on selected action
function setFields(action) {
  let fields = {}

  switch (action) {
    case 'subscribe': fields.Subscribed = true; break;
    case 'unsubscribe': fields.Subscribed = false; break;
    case 'rsvp_yes': fields.RSVP = true; break;
    case 'rsvp_no': fields.RSVP = false; break;
  }

  return fields
}

// Create a new Contact with the given field pre-selected
function createContact(phoneNumber, action, callback) {
  let fields = setFields(action)
  fields['Phone Number'] = phoneNumber

  contacts.create(fields, (err) => {
    if (err) {
      return callback(err)
    }
    callback(null, 'Contact created successfully!')
  })
}

// Query Airtable for the relevant phone number record 
function updateContact(phoneNumber, action, callback) {
  contacts.select({
    filterByFormula: `{Phone Number} = "${phoneNumber}"`,
  }).eachPage(function page(records) {
    let contact = records[0]

    // Add contact to database if we don't have it
    if (!contact) {
      return createContact(phoneNumber, action, callback)
    }

    // Otherwise, update existing contact
    let fields = setFields(action)
    contacts.update(contact.id, fields, (err) => {
      if (err) {
        return callback(err)
      }
      callback(null, 'Contact updated successfully!')
    })
    
  }, callback)
}

// Handle incoming SMS responses
exports.handler = (context, event, callback) => {
  // Get incoming phone number and desired action from Studio flow
  let phoneNumber = event.phone_number
  let action = event.action

  // Add or update contact record in Airtable
  updateContact(phoneNumber, action, (err, message) => {
    // Bubble an error back up to our Studio flow
    if (err) {
      return callback(err)
    }

    // Passing a null as the first argument tells Studio there was no error
    // during execution, which will branch off into the "success" path
    callback(null, { message })
  })
}