app.js

const http = require('http')
const express = require('express')
const axios = require('axios')
const bodyParser = require('body-parser')
const PORT = process.env.PORT || 1337
const { google } = require('googleapis')
const API_URL = 'https://dm-meeting-app.firebaseio.com/round4.json'
const TIME_ZONE = 'America/Phoenix'
const FILE_LOCATION_URL =
  'https://api.github.com/repos/jsjoeio/100-days-twilio-twitter/contents/logs.md'

if (process.env.NODE_ENV !== 'production') {
  require('dotenv').config()
}

/* Twitter API */
const Twitter = require('twitter')
const twitterClient = new Twitter({
  consumer_key: process.env.TWITTER_CONSUMER_KEY,
  consumer_secret: process.env.TWITTER_CONSUMER_SECRET,
  access_token_key: process.env.TWITTER_ACCESS_TOKEN_KEY,
  access_token_secret: process.env.TWITTER_ACCESS_TOKEN_SECRET
})

/* Twilio Credentials */
const accountSid = process.env.ACCOUNT_SID
const authToken = process.env.AUTH_TOKEN
const client = require('twilio')(accountSid, authToken)

/* Google Firebase API */
let bearerAccessToken
const serviceAccount = require('./serviceAccountKey.json')
const scopes = [
  'https://www.googleapis.com/auth/userinfo.email',
  'https://www.googleapis.com/auth/firebase.database'
]
const jwtClient = new google.auth.JWT(
  serviceAccount.client_email,
  null,
  serviceAccount.private_key,
  scopes
)
jwtClient.authorize(function(error, tokens) {
  if (error) {
    console.log('Error making request to generate access token:', error)
  } else if (tokens.access_token === null) {
    console.log(
      'Provided service account does not have permission to generate access tokens'
    )
  } else {
    const accessToken = tokens.access_token
    setAccessToken(accessToken)
  }
})

const app = express()

app.use(bodyParser.urlencoded({ extended: false }))

function setAccessToken(accessToken) {
  bearerAccessToken = accessToken
}

app.post('/sms', (req, res) => {
  if (req.body.From === process.env.PHONE_NUMBER) {
    getMessage(req).then(messageObject => {
      postTweet(messageObject)
      sendToGitHub(messageObject)
    })

    res.set('Content-Type', 'application/xml')
    res.send('<Response/>')
  }
})

async function getMessage(req) {
  /* Set the round that you're on here: */
  const round = 4

  /* Set the hashtag you want to use here: */
  const hashTag = '#100DaysOfCode'

  const messageObject = {}
  const previousDay = await getDayCount().then(daysObject => {
    if (daysObject !== null) {
      let objectId = Object.keys(daysObject)[Object.keys(daysObject).length - 1]
      return daysObject[objectId].day
    } else {
      return 0
    }
  })
  const currentDay = previousDay + 1
  const todaysDate = getTodaysDate(
    new Date().toLocaleString(
      'en-US',
      { timeZone: TIME_ZONE }
    )
  )
  const text = req.body.Body
  messageObject.tweet = `R${round}|D${currentDay}:\n${text} \n${hashTag}`
  messageObject.day = currentDay
  messageObject.date = todaysDate
  messageObject.text = text
  return messageObject
}

async function sendToGitHub(messageObject) {
  const currentFile = await getCurrentFileFromGitHub()
  const updatedFileObject = await createUpdatedFileObject(
    currentFile,
    messageObject
  )
  putTweetToGitHub(updatedFileObject)
}

function getDayCount() {
  return axios
    .get(API_URL, { headers: { Authorization: `Bearer ${bearerAccessToken}` } })
    .then(function(response) {
      return response.data
    })
    .catch(function(error) {
      console.log(error)
    })
}

function getTodaysDate(today) {
  // 'today' will enter the function like "8/5/2018, 7:22:11 AM" so we slice it.
  return today.slice(0, 9)
}

function postTweet(messageObject) {
  twitterClient
    .post('statuses/update', {
      status: messageObject.tweet
    })
    .then(function(tweet) {
      let message = 'Tweet posted successfully! 😄'
      sendText(message)
      postTweetToDB(messageObject)
    })
    .catch(function(error) {
      let message = `Uh oh...Looks like we got an error. Tweet not posted :(`
      sendText(message)
      console.log(`Error: ${JSON.stringify(error)}`)
    })
}

function postTweetToDB(messageObject) {
  axios
    .post(API_URL, messageObject, {
      headers: { Authorization: `Bearer ${bearerAccessToken}` }
    })
    .then(function(response) {
      console.log('Successfully posted tweet to DB.')
    })
    .catch(function(error) {
      console.log(error)
    })
}

function getCurrentFileFromGitHub() {
  return axios
    .get(FILE_LOCATION_URL, {
      headers: { Authorization: `Basic ${process.env.GITHUB_AUTH_TOKEN}=` }
    })
    .then(function(response) {
      return response.data
    })
    .catch(function(error) {
      console.log(error)
    })
}

function combineOldContentNewContent(currentFile, messageObject) {
  //Get current content -> converts it from base64 to readable string.
  const currentContent = Buffer.from(currentFile.content, 'base64').toString(
    'utf8'
  )
  //Add log to the end of file with day, date and text
  const combinedContent = `${currentContent}\n### Day ${messageObject.day}: ${
    messageObject.date
  }\n${messageObject.text}\n`
  //Convert back to base64
  return Buffer.from(combinedContent, 'utf8').toString('base64')
}

function getPathFromFileLocationUrl(FILE_LOCATION_URL) {
  //Find the index position of 'contents' in the url. Add 10 to exclude '/contents/'
  const position = FILE_LOCATION_URL.indexOf('/contents/') + 10
  const path = FILE_LOCATION_URL.substring(position)
  return path
}

function createUpdatedFileObject(currentFile, messageObject) {
  const updatedFileObject = {
    message: `add Day ${messageObject.day} using Twilio`,
    committer: {
      name: process.env.NAME,
      email: process.env.EMAIL
    },
    content: combineOldContentNewContent(currentFile, messageObject),
    sha: currentFile.sha,
    branch: 'master',
    path: getPathFromFileLocationUrl(FILE_LOCATION_URL)
  }
  return JSON.stringify(updatedFileObject)
}

function putTweetToGitHub(fileObject) {
  axios
    .put(FILE_LOCATION_URL, fileObject, {
      headers: { Authorization: `Basic ${process.env.GITHUB_AUTH_TOKEN}==` }
    })
    .then(function(response) {
      console.log('Successfully updated file on GitHub!')
    })
    .catch(function(error) {
      console.log(error)
    })
}

function sendText(message) {
  client.messages
    .create({
      to: process.env.PHONE_NUMBER,
      from: process.env.TWILIO_NUMBER,
      body: message
    })
    .then(message => console.log(message.sid))
}

http.createServer(app).listen(PORT, () => {
  console.log(`Express server listening on port ${PORT}. Let's get coding 🎉 !`)
})