export.rb

class Export < ActiveRecord::Base
  include ActionView::Helpers::DateHelper
  include ActionView::Helpers::NumberHelper
  
  has_attached_file :attachment, :storage => :s3
  
  belongs_to :organization
  belongs_to :user
  
  after_create :process
  def process
    send_later(:process!)
  end
  
  def process!
    return if finished?
    begin
      update_attribute(:state, "running")
      csv = tempfile
      @joins = [:names, :addresses, :email_addresses, :web_addresses]
      smart_tag = organization.smart_tags.find(settings[:smart_tag])
      @conditions = smart_tag.conditions
      headers, n_names, n_addresses, n_email_addresses, n_phone_numbers, n_web_addresses = organization.personas.csv_headers
      csv.puts headers.to_csv
      @row_counter = 0
      @lasttime = Time.now
      @starttime = Time.now
      @count = organization.personas.count(:conditions => @conditions)

      organization.personas.find_each(:conditions => @conditions, :include => @joins) do |persona|
        csv.puts persona.to_csv(n_names, n_addresses, n_email_addresses, n_phone_numbers, n_web_addresses)
        # debugging...{} 
        @row_counter += 1
        if @row_counter%100 == 0
          currtime = Time.now
          str = ""
          str << "#{(@row_counter/@count.to_f * 100).to_i}% complete "
          str << "(#{@row_counter} of #{@count} records). "
          str << "Elapsed: #{distance_of_time_in_words_to_now(@starttime)} (#{"%0.2f" % (currtime - @lasttime)}sec/h). "
          memory_usage = `ps -o rss= -p #{Process.pid}`.to_i # in kilobytes
          str << "Memory used: #{number_to_human_size(memory_usage*1000)}. "
          self.update_attribute(:detail, str) 
          @lasttime = Time.now
          # csv.flush
        end
      end
      # Send to S3
      self.attachment = csv
      self.state = "finished"
      self.detail = "Processed in #{distance_of_time_in_words_to_now(@starttime)}"
      self.save!
      # send email
      UserNotifier.deliver_finished_export(self)
    rescue Exception => e
      notify_hoptoad(e)
      self.update_attribute(:state, "failed")
      raise e
    end
  end
  
  def tempfile
    @tempfile ||= Tempfile.new(filename)
  end
  
  def filename
    "#{id}.#{format}"
  end
end