Add custom method to export table as CSV file for ActiveAdmin Resource + scope items from filter + save csv file compatible with Russian Microsoft Office Excel

some_active_admin_resource.rb

  filter :reception_reception_date, as: :date_range, label: Reception.human_attribute_name(:reception_date_full)
  
  collection_action :download_report, :method => :get do
    services = Service.includes(:order, reception: [{medic: :clinic_medics}]).where{ orders.orderable_id != nil } # necessary model
    if params[:q] && params[:q][:reception_reception_date_gte].length > 1 
      services = services.where("receptions.reception_date >= ?", params[:q][:reception_reception_date_gte])
    end
    if params[:q] && params[:q][:reception_reception_date_lte].length > 1 
      services = services.where("receptions.reception_date < ?", params[:q][:reception_reception_date_lte])
    end    
    csv = CSV.generate( encoding: 'Windows-1251' ) do |csv|
      # add headers
      csv << [
                I18n.t('services.finance_report.order_date'), 
                I18n.t('services.finance_report.order_number')
              ]
      # add data
      services.each do |s|
        medic = s.reception.medic

        performer_id = medic.performer_id
        agreeement_number = medic.proper_agreeement_number

        csv << [ s.created_at, s.order.order_number ]
      end      
    end
    # send file to user
    send_data csv.encode('Windows-1251'), type: 'text/csv; charset=windows-1251; header=present', disposition: "attachment; filename=accounting_report.csv"
  end

  action_item only: :index do
    link_to(I18n.t('active_admin.save_csv'), params.merge(:action => :download_report))
  end 

  index :download_links => false do
    # necessary fields
  end