promise_promise_promise_async_series_callback_then_promise_promise.js

promise-promise_promise-async-series-callback-then-promise-promise.js

const async = require('async');
const axios = require('axios');
const CronJob = require('cron').CronJob;

let courseList = [
  {courseId: 3},
  {courseId: 4},
  {courseId: 5},
  {courseId: 6}
];

const cronFormat = `26 16 27 Jan *`;  // need to run this script? change here

console.log(`Starting cron at: ${cronFormat}\n`);

const job = new CronJob(cronFormat,
  /**
   * On cron start.
   */
  function () {
    console.log('Here I am.\n');

    areYouComedyMe().then(function() {
      console.log('\nI should be last.');

      job.stop();
    });
  },
  /**
   * On cron complete.
   */
  function () {
    console.log('Yeah! We are finished.');
  },
  /**
   * Start the job right now.
   */
  true
);

/**
 * Never write shit code like this again.
 *
 * @returns {IDontGiveAFuck}
 */
function areYouComedyMe() {
  // return 1
  return axios.get('http://google.com/?q=bheja').then(function() {
    console.log('Level 1');

    // return 2
    return axios.get('http://google.com/?q=tori_laure').then(function() {
      console.log('Level 2');

      // return 3
      return new Promise(function(resolve, reject) {
        console.log('\nBefore each series:\n')

        // async.eachSeries
        async.eachSeries(courseList, function (course, callback) {
          let _callback = callback;

          // return 4
          return axios.get('http://google.com/?q=' + course.courseId)
            .then(function () {

              // return 5
              return axios.get('http://google.com/?q=' + course.courseId)
                .then(function (result) {
                  return async.waterfall([
                    function(callback) {
                        callback(null, 'one', 'two');
                    },
                    function(arg1, arg2, callback) {
                        // arg1 now equals 'one' and arg2 now equals 'two'
                        callback(null, 'three');
                    },
                    function(arg1, callback) {
                        // arg1 now equals 'three'
                        callback(null, 'done');
                    }
                  ], function (err, result) {
                    if (err) {
                      console.log('Well well.');
                    }

                    console.log('Level ' + course.courseId);
                  });
                }); // return 5

            }).then(function() {
              // finish single async operation
              _callback(null);
            }); // return 4

          }, function (err) {
            if (err) {
              reject(err);
            }

            resolve(null);
          }); // async.eachSeries

      }); // return 3

    }); // return 2

  }); // return 1
}