returning_users.js

const co = require('co');
const moment = require('moment');

const User = require('../../app/models/user');
const Workout = require('../../app/models/workout');

/*
Script used to get an accurate estimate of returning users on a specific date
( + the following day ).
E.g. On 13th of July we sent an email. The question is how many users that dind't
open the application in X (range) days have opened it after receiving the email
(on 13th and 14th).
*/
module.exports = function() {
  co(function*() {

    // given date
    const date = moment('2017-06-13');
    // given range of innactivity (e.g. 60, 30)
    const range = 30;

    // count of returning users
    let count = 0;
    // counter used for iteration status
    let status = 0;

    // get all users with their last workouts prepared in the given range
    const users = yield User.find({
      'workoutPrepStatus.preparedAt': { $gte: date.clone().subtract(range + 1, 'days').toDate()}
      }, '_id')
      .lean();

    // iterate over users one by one
    //eslint-disable-next-line
    for (const u of users) {

      status +=1 ;
      console.log(`${status} / ${users.length}`);

      // get the fetched workouts of the user on the given date + next day
      const returningWorkouts = yield Workout.find({
        userId: u._id,
        fetched: true,
        preparedFor: {
          $gte: date.toDate(),
          $lte: date.clone().add(2, 'days').toDate(),
        }
      }, '_id').lean();

      // if he has fetched a workout -> he opened the app -> he is a returning user
      if (returningWorkouts.length > 0) {

        // get all workouts geerated for user in the given range
        const previousWorkouts = yield Workout.find({
          userId: u._id,
          preparedFor: {
            $gte: date.clone().subtract(range, 'days').toDate(),
            $lte: date.toDate(),
          }
        }, 'fetched')
        .lean();

        // if all these workouts weren't fetched -> user didn't open the app
        // ->  he was inactive those day
        if (previousWorkouts.every(x => x.fetched === false)) {
          // if this is the case then increment the counter of ret. users
          count += 1;
        }

      }
    }

    console.log('found ', count, ' returning users');
    process.exit(0);

  });

}