RobDWaller/fableau

'use strict'

import DateTime from '../helper/date-time.js'

/**
 * Maps the page metrics data from Facebook to a Tableau friendly format
 *
 * @author Rob Waller <rdwaller1984@googlemail.com>
 */
class PageMetrics {
  /**
   * @param array data
   */
  constructor (data) {
    if (typeof data === 'undefined') {
      throw new Error('Data is not defined!!')
    }

    this.data = data
  }

  /**
   * Map the data to a Tableau format
   *
   * @return array
   */
  getTableauData () {
    if (!Array.isArray(this.data) || this.data.length === 0) {
      throw new Error('Data is not an array or is an empty!!')
    }

    let data = this.data.reduce((a, b) => {
      b.values.map((value) => {
        let c = {
          'page_id': parseInt(b.id.split('/')[0]),
          [b.name + '_' + b.period]: value.value,
          'created_at': this.convertDateToTableauDate(value.end_time)
        }

        a.push(c)
      })

      return a
    }, []).reduce((a, b) => {
      if (typeof (a[b.created_at]) === 'undefined') {
        a[b.created_at] = b

        return a
      }

      a[b.created_at] = Object.assign(a[b.created_at], b)

      return a
    }, {})

    return Object.keys(data).map(key => {
      return data[key]
    })
  }

  /**
   * Convert a Facebook date time string to a Tableau date time string
   *
   * @param string dateTimeString
   * @return string
   */
  convertDateToTableauDate (dateTimeString) {
    let date = new DateTime()

    return date.getTableauTimeString(dateTimeString)
  }
}

export default PageMetrics