Class file to download mixpanel data and convert to CSV

mixpanel_extract.rb

require 'mixpanel_client'
require 'csv'
require 'multi_json'
require 'net/http'

class MixpanelExtract
  attr_reader :filename, :request_uri

  def initialize(config, for_date)
    @client = Mixpanel::Client.new(config[:mixpanel_auth])
    @staging_folder = config[:staging_folder]
    @event_name = config[:event_name]
    @for_date = for_date
    @filename = "#{@staging_folder}/#{@event_name}.events-#{@for_date}.json"
    @extract_list = config[:extract_list].split(',')
    @request_uri = @client.request_uri('export', params)
    @limit = config[:limit]
  end

  def params
    params = {
      event: '["' + @event_name + '"]',
      from_date: @for_date,
      to_date: @for_date,
    }
    params[:Limit] = @limit if(@limit != nil)
    params
  end

  def process_date
    end_point = 'data.mixpanel.com'
    resource = @request_uri[/#{end_point}\K.*/]
    puts "End Point: #{end_point}"
    puts "Resource: #{resource}"

    Net::HTTP.start(end_point, { :use_ssl => true }) do |http|
       http.request_get(resource) do |response|
        open @filename, 'w' do |io|
          response.read_body do |chunk|
            io.write chunk
          end
        end
      end
    end
  end

  def flatten_event_properties(jevent)
    new_event = {}
    new_event["event"] = jevent["event"]
    new_event.merge!(jevent["properties"])
    new_event
  end

  def generate_headers(row_hash)
    row_hash.keys
  end

  def transform(file_in, file_out)
    CSV.open(file_out,"wb", {:col_sep => "\t"}) do |csv|
      File.open(file_in).each do |line|
        flattened_line = flatten_event_properties(MultiJson.load(line))

        data = []
        @extract_list.each do |k|
          data << flattened_line[k]
        end
        csv << data
      end
    end
  end

end