mapping.rb

require 'singleton'

module Xing
  module Industries
    class Mapping
      include Singleton

      JSON_PATH      = '../../../../industries/mapping.json'
      OLD_DEFAULT    = 77
      NEW_DEFAULT    = 230_000
      HIGHEST_OLD_ID = 200

      attr_reader :mapping

      def initialize
        json = JSON.parse File.read(File.expand_path(JSON_PATH, __FILE__))

        @mapping = {
          old_to_new: json["old_to_new"],
          new_to_old: json["new_to_old"]
        }
      end

      def self.to_new_format(id:)
        instance.to_new_format(id: id)
      end

      def self.to_old_format(id:)
        instance.to_old_format(id: id)
      end

      def map(id:)
        warn "[DEPRECATION] `#map` is deprecated.  Please use one of the new methods `to_new_format` and `to_old_format` instead."
        if id < HIGHEST_OLD_ID
          mapping[:old_to_new].fetch(id.to_s, NEW_DEFAULT)
        else
          mapping[:new_to_old].fetch(id.to_s, OLD_DEFAULT)
        end
      end

      def to_new_format(id:)
        return unless id
        return id if id > HIGHEST_OLD_ID

        mapping[:old_to_new].fetch(id.to_s, NEW_DEFAULT)
      end

      def to_old_format(id:)
        return unless id
        return id if id < HIGHEST_OLD_ID

        mapping[:new_to_old].fetch(id.to_s, OLD_DEFAULT)
      end
    end
  end
end