module HealthDataStandards
  module Import
    module C32
      class ImmunizationImporter < SectionImporter

        def initialize
          @entry_xpath = "//cda:section[cda:templateId/@root='2.16.840.1.113883.3.88.11.83.117']/cda:entry/cda:substanceAdministration"
          @code_xpath = "./cda:consumable/cda:manufacturedProduct/cda:manufacturedMaterial/cda:code"
          @description_xpath = "./cda:consumable/cda:manufacturedProduct/cda:manufacturedMaterial/cda:code/cda:originalText/cda:reference[@value]"
          @refusal_resason_xpath = "./cda:entryRelationship[@typeCode='RSON']/cda:act[cda:templateId/@root='2.16.840.1.113883.10.20.1.27']/cda:code"
          @check_for_usable = true               # Pilot tools will set this to false
        end

        # Traverses that HITSP C32 document passed in using XPath and creates an Array of Entry
        # objects based on what it finds                          
        # @param [Nokogiri::XML::Document] doc It is expected that the root node of this document
        #        will have the "cda" namespace registered to "urn:hl7-org:v3"
        #        measure definition
        # @return [Array] will be a list of Entry objects
        def create_entries(doc,id_map = {})
          immunization_list = []
          entry_elements = doc.xpath(@entry_xpath)
          entry_elements.each do |entry_element|
            immunization = Immunization.new
            extract_codes(entry_element, immunization)
            extract_dates(entry_element, immunization)
            extract_description(entry_element, immunization, id_map)
            extract_refusal(entry_element, immunization)
            extract_performer(entry_element, immunization)
            if @check_for_usable
              immunization_list << immunization if immunization.usable?
            else
              immunization_list << immunization
            end
          end
          immunization_list
        end
    
        private
        def extract_refusal(parent_element, immunization)
          negation_indicator = parent_element['negationInd']
          unless negation_indicator.nil?
            immunization.refusal_ind = negation_indicator.eql?('true')
            if immunization.refusal_ind
              refusal_reason_element = parent_element.at_xpath(@refusal_resason_xpath)
              if refusal_reason_element
                immunization.refusal_reason = {'code' => refusal_reason_element['code'],
                                               'codeSystem' => 'HL7 No Immunization Reason'}
              end
            end
          end
        end
    
        def extract_performer(parent_element, immunization)
          performer_element = parent_element.at_xpath("./cda:performer")
          immunization.performer = import_actor(performer_element) if performer_element
        end
      end
    end
  end
end