require "date"
require "date/delta"

module HealthDataStandards
  module Import
    module CCR
      class ProviderImporter
        include Singleton

        # Extract Healthcare Providers from CCR
        #
        # @param [Nokogiri::XML::Document] doc It is expected that the root node of this document
        #        will have the "ccr" namespace registered to "urn:astm-org:CCR"
        # @return [Array] an array of providers found in the document
        def extract_providers(doc)

          # Providers are identified as the 'Source' for entries in the CCR.   Sources can also include the patient, relatives, insurance companies, etc
          actorIDs = doc.xpath("//ccr:Source/ccr:Actor/ccr:ActorID")
          uniqueActorIDs = {}
          actorIDs.each do |actorID|
            uniqueActorIDs[actorID.content] = actorID.content
          end
          actorIDs = uniqueActorIDs.keys
          providers = actorIDs.map do |actorID|
            provider = nil
            actor = doc.at_xpath("//ccr:ContinuityOfCareRecord/ccr:Actors/ccr:Actor[ccr:ActorObjectID = \"#{actorID}\"]")
            if(actor)
              # Differentiate care providers by content of this field
              if actor.at_xpath("./ccr:Source/ccr:Actor/ccr:ActorRole/ccr:Text") && 
                 actor.at_xpath("./ccr:Source/ccr:Actor/ccr:ActorRole/ccr:Text").content.downcase =~ /care provider/
                provider = {}
                if actor.at_xpath('./ccr:Person/ccr:Name/ccr:CurrentName/ccr:Given')
                  provider[:given_name] = actor.at_xpath('./ccr:Person/ccr:Name/ccr:CurrentName/ccr:Given').content
                  provider[:family_name] = actor.at_xpath('./ccr:Person/ccr:Name/ccr:CurrentName/ccr:Family').content
                end
                if actor.at_xpath('./ccr:Specialty/ccr:Text')
                  provider[:specialty]    = actor.at_xpath('./ccr:Specialty/ccr:Text').content
                end
                if actor.at_xpath("ccr:Telephone/ccr:Value")
                  provider[:phone] = actor.at_xpath("ccr:Telephone/ccr:Value").content
                end
                # Not clear precisely how NPI would be specified
                npi_ids = actor.at_xpath("./ccr:IDs[ccr:Type/ccr:Text = \"NPI\"]")
                if npi_ids
                  npi_id = npi_ids.at_xpath("./ccr:ID")
                  npi = npi_id.content
                  if Provider.valid_npi?(npi)
                    provider[:npi] = npi
                  else
                    puts "Warning: Invalid NPI (#{npi})"
                  end   #valid NPI
                end #has NPI

              end #is a provider
            end   #is an actor
              provider
          end.compact
        end
      end
    end
  end
end