notifyFollowers.js

"use strict";

var Twitter = require('twitter');
var sendEmail = require('./email.js');
var config = require('./config.js');
var async = require('./async.js').async;

Array.prototype.subtract = function(a) {
    return this.filter(function(i) { return a.indexOf(i) === -1; });
};

function getFollowers(T, screenName) {
  return new Promise((resolve, reject) => {
    T.get('followers/ids', { screen_name: screenName },  function (err, data, response) {
      if (err) {
        console.log('err: ' + JSON.stringify(err));
        return reject(new Error(err));
      }
      if (data.ids) { 
        // console.log('ids: ' + data.ids);
        // console.log('ids: ' + JSON.stringify(data));
        // console.log('id0: ' + data.ids[0]);
        // console.log('response: ' + JSON.stringify(response));
        var b = response.body;
        var idStrings = b.substring(b.indexOf('[') + 1, b.indexOf(']')).split(',');
        //console.log('resonse.ids: ' + idStrings);
        resolve(idStrings);
      } else {
        return reject(new Error('returned null list of followers!'));
      }
    });
  });
}

function printArrayTypes(array, arrayName) {
  var arrayString = array.map(e => { return typeof(e); });
  console.log("types for " + arrayName + ": " + arrayString);
}

function notify(emailOptions, message) {
  let localEmailOptions = JSON.parse(JSON.stringify(emailOptions));
  localEmailOptions.htmlMessage = message;
  sendEmail(localEmailOptions)
    .then(res => console.log('sent notification email! ' + res.response))
    .catch(err => console.log('failed to send notification email! ' + err.stack));
}

function getFollowerFromIds(T, ids) {
  return new Promise((resolve, reject) => { 
    console.log('looking up user ids: ' + ids + ', typeof id: ' + typeof(ids.toString()));
    T.get('users/lookup', { user_id: ids.toString() },  function (err, data, response) {
      if (err) {
        console.log('err: ' + JSON.stringify(err));
        return reject(new Error(err));
      }
      if (data) {
        console.log('follower ' + JSON.stringify(data, null, 2) + ' from ids: ' + ids);
        resolve(data);
      } else {
        console.log('got null data from user lookup api, response: ' + response);
        resolve([]);
      }
    });
  });
}

var checkNotify = async(function* (T, followersList, emailOptions, screenName) {
  try {
    var latestIds = yield getFollowers(T, screenName);
    // printArrayTypes(latestIds, 'fresh idStrings');
    // printArrayTypes(followersList, 'followersList');
    // console.log('\r\ngot latestIds: ' + latestIds + '\r\nfollowersList: ' + followersList);
    let follows = latestIds.subtract(followersList);
    let unfollows = followersList.subtract(latestIds);
    // console.log('\r\ngot follows: ' + follows + '\r\nunfollows: ' + unfollows);
    let notificationMessage = {};
    if (follows && follows.length > 0) {
      console.log('found new follows: ' + follows);
      notificationMessage.followProfiles = yield getFollowerFromIds(T, follows);
      follows.map(e => { followersList.push(e); });
    }
    if (unfollows && unfollows.length > 0) {
      console.log('found new unfollows: ' + unfollows);
      notificationMessage.unfollowProfiles = yield getFollowerFromIds(T, unfollows);
      for (let i = 0, ulen = unfollows.length; i < ulen; i++) {
        for (let j = 0, flen = followersList.length; j < flen; j++) {
          if (followersList[j] == unfollows[i]) {
            console.log('removing unfollows: ' + unfollows[i] + 
              ' == followersList: ' + followersList[j]);
            followersList.splice(j, 1);
          }
        }
      }
    }
    if (Object.keys(notificationMessage).length > 0) {
      console.log('found changes in followers list: ' + JSON.stringify(notificationMessage));
      notify(emailOptions, JSON.stringify(notificationMessage, null, 2));
    } else {
      console.log('no changes found in followers list: ' + 
        JSON.stringify(notificationMessage));
    }
  } catch (e) {
    console.log('failed in checkNotify: ' + JSON.stringify(e) + e.stack);
  }
});

function notificationLoop(T, followersList, emailOptions, checkIntervalSeconds) {
  console.log('setup to check api every ' + checkIntervalSeconds + ' seconds');
  setInterval(() => {
    console.log((new Date()).toString() + ' checking followers');
    checkNotify(T, followersList, emailOptions);
  }, checkIntervalSeconds * 1000);
}

var testNotify = async(function* (T, ids, emailOptions) {
  try {
    console.log('emailing: ');
    var followerFromID = yield getFollowerFromIds(T, [1026, 160763]);
    console.log('follower from id: ' + JSON.stringify(followerFromID));
    var result = yield notify(emailOptions, JSON.stringify(followerFromID));
    console.log('notify result: ' + JSON.stringify(result));
  } catch(e) {
    console.log(e.stack);
  }
});

function main() {
 
  console.log('starting, using config: ' + JSON.stringify(config));
  var T = new Twitter({
      consumer_key:         config.twitOptions.consumer_key,
      consumer_secret:      config.twitOptions.consumer_secret,
      access_token_key:     config.twitOptions.access_token,
      access_token_secret:  config.twitOptions.access_token_secret
  });
  //testNotify(T, [1026, 160763], config.emailOptions);
  // var initialFollowers = []
  // getFollowers(T, config.screenName)
  //   .then(res => { 
  //     initialFollowers = res; 
  //     console.log('initial followers ids: ' + res); 
  //     return initialFollowers;
  //   })
  //   .then(res => {
  //     getFollowerFromIds(T, res[0])
  //       .then(res => console.log('res: ' + JSON.stringify(res)))
  //   })
  //   .catch(err => console.log('err: ' + err.stack));

  getFollowers(T, config.screenName)
    .then(initialFollowers => { 
      console.log('initial followers ids: ' + initialFollowers);
      if (initialFollowers && initialFollowers.length > 0) {
        return initialFollowers; 
      } else {
        throw new Error('failed to get initial followers list');
      }
    })
    .then(res => {
      notificationLoop(T, res, config.emailOptions, config.checkIntervalSeconds);
    })
    .catch(err => {
      console.log('failed in main: ' + err.stack);
    });
}

if (require.main === module) {
  main();
}