current_country.rb

class CurrentCountry
  def initialize(session, env, freegeoip)
    @session = session
    @env = env
    @freegeoip = freegeoip
  end

  def fetch
    (
      Country.find_by(id: session[:country_id]) ||
      Country.find_by(alpha2: country_code) ||
      Country.default
    ).tap do |c| 
      session[:country_id] = c.id 
    end
  end

  private
  attr_reader :session, :env, :freegeoip

  def country_code
    freegeoip.locate(
      env['action_dispatch.remote_ip']
    ).country_code
  end
end