module QME
  module Importer
    # General helpers for working with codes and code systems
    class CodeSystemHelper
      CODE_SYSTEMS = {
        '2.16.840.1.113883.6.1' =>    'LOINC',
        '2.16.840.1.113883.6.96' =>   'SNOMED-CT',
        '2.16.840.1.113883.6.12' =>   'CPT',
        #'2.16.840.1.113883.3.88.12.80.32' => 'CPT',
        '2.16.840.1.113883.6.88' =>   'RxNorm',
        '2.16.840.1.113883.6.103' =>  'ICD-9-CM',
        '2.16.840.1.113883.6.104' =>  'ICD-9-CM',
        '2.16.840.1.113883.6.90' =>   'ICD-10-CM',
        '2.16.840.1.113883.6.14' =>   'HCPCS',
        '2.16.840.1.113883.6.59' =>   'CVX',
        '2.16.840.1.113883.6.238' =>   'CDC-RE'
      }
      
      # Returns the name of a code system given an oid
      # @param [String] oid of a code system
      # @return [String] the name of the code system as described in the measure definition JSON
      def self.code_system_for(oid)
        CODE_SYSTEMS[oid] || "Unknown"
      end
      
      # Returns the oid for a code system given a codesystem name
      # @param [String] the name of the code system
      # @return [String] the oid of the code system
      def self.oid_for_code_system(code_system)
        CODE_SYSTEMS.invert[code_system]
      end
      
      # Returns the whole map of OIDs to code systems
      # @terurn [Hash] oids as keys, code system names as values
      def self.code_systems
        CODE_SYSTEMS
      end
    end
  end
end