Expensify Invoice Constructor

gistfile1.js

function Invoicerizer(date, duration, tasks) {
  this.date = date;
  this.duration = duration;
  this.tasks = tasks;
}
 
Invoicerizer.prototype = {
  init: function() {
    $('.expensicons.expensicons-plus').trigger('click');
 
    this.wait(2000)
    .then( this.createExpense.bind(this) )
    .then( this.openTimeTab.bind(this) )
    .then( this.fillInInputs.bind(this) )
    .then( this.fillInDate.bind(this) )
    .then( function() {
      $('.dialog_wrapper .js_save.expenseFormSave:last').trigger('click');
    });
  },
 
  createExpense: function() {
    $('#createexpense_button').trigger('click');
    return this.wait(1000);
  },
    
  openTimeTab: function() {
    $('li[data-mode=time]').trigger('click');
    return this.wait(500);
  },
    
  fillInInputs: function() {
    $('form[data-mode=time] input[name=hour]:first').val(this.duration);
    $('form[data-mode=time] input[name=rate]:first').val(50);
    $('form[data-mode=time] input[name=reimbursable]').prop('checked', true);
    $('form[data-mode=time] [name=category]').val('21');
    $('form[data-mode=time] input[name=comment]:first').val(this.tasks);
    return this.wait(0);
  },
 
  fillInDate: function() {
    var self = this;
    var monthIndex = this._getDateMonthIndex();
    $('form[data-mode=time] [name=created]').focus();
    
    var setTheMonth = function() {
      window.setTimeout(function() {
        var diff = self._currentMonthDiff( monthIndex );
        if( diff === 0 ) return;
        else diff > 0 ? self._goToPrevMonth() : self._goToNextMonth();

        return setTheMonth();
      });
    };

    setTheMonth();

    return this.wait(1000)
      .then(function() {
        var day = self._getDateDay();
        $('#ui-datepicker-div td:contains('+ day +')')
          .filter(function(i, el) { return $(el).text() === day; })
          .trigger('click');
      })
      .then(function() { return self.wait(); });
  },
    
  wait: function(time) {
    return new Promise(function(response, rej) {
      if( !time ) time = 1000;
      window.setTimeout(function() {
        response.resolve();
      }, time);
    });
  },
    
  _getDateDay: function() {
    return this.date.split('/')[1];
  },

  _getDateMonthIndex: function() {
    return parseInt(this.date.split('/')[0], 10) - 1;
  },

  _currentMonthDiff: function(monthIndex) {
    return this._getMonthIndex( $('#ui-datepicker-div .ui-datepicker-month').text() ) - monthIndex;
  },

  _goToNextMonth: function() {
    return window.setTimeout(function() {
      $('#ui-datepicker-div .ui-datepicker-next').click();
    });
  },

  _goToPrevMonth: function() {
    return window.setTimeout(function() {
      $('#ui-datepicker-div .ui-datepicker-prev').click();
    });
  },

  _getMonthIndex: function(month) {
    month = month.toLowerCase().trim();
    months = ['january', 'february', 'march', 'april', 'may', 'june', 'july', 'august', 'september', 'october', 'november', 'december'];
    return months.indexOf(month);
  }
}