extract unique referer

referer.rb

require 'json'                                                                                                                                                               
                                                                                                                                                                             
file = File.read 'ads_merg_conf.json'                                                                                                                                        
json = JSON.parse file                                                                                                                                                       
                                                                                                                                                                             
ir = json.flat_map do |placement, values|                                                                                                                                    
  next unless values.is_a? Hash                                                                                                                                              
  values['flights'].to_a.map do |f|                                                                                                                                          
    f['include'].to_a.map do |i|                                                                                                                                             
      i.to_h['where'].to_h['referer']                                                                                                                                        
    end                                                                                                                                                                      
  end                                                                                                                                                                        
end.flatten.uniq.compact                                                                                                                                                     
                                                                                                                                                                             
puts ir.join(', ')