module HQMF
  module Util
    # General helpers for working with codes and code systems
    class HQMFTemplateHelper

      def self.definition_for_template_id(template_id, version = "r1")
        template_id_map(version)[template_id]
      end

      def self.template_id_map(version)
        if @id_map.blank?
          @id_map = {
            'r1' => JSON.parse(File.read(File.expand_path('../hqmf_template_oid_map.json', __FILE__))),
            'r2' => JSON.parse(File.read(File.expand_path('../hqmfr2_template_oid_map.json', __FILE__))),
            'r2cql' => JSON.parse(File.read(File.expand_path('../hqmfr2cql_template_oid_map.json', __FILE__)))
          }
        end
        @id_map[version]
      end

      def self.template_id_by_definition_and_status(definition, status, negation, version)
        case version
        when "r1"
          kv_pair = template_id_map(version).find { |k, v| v['definition'] == definition &&
                                                 v['status'] == status &&
                                                 v['negation'] == negation}
        when "r2", "r2cql"
          kv_pair = template_id_map(version).find { |k, v| v['definition'] == definition &&
                                                 v['status'] == status}
        end
        if kv_pair
          kv_pair.first
        else
          nil
        end
      end

      # Returns a list of all hqmf_oids (regardless of version) for the combination of definition and status
      def self.get_all_hqmf_oids(definition, status)
        status ||= ""
        version_negation_combinations = [{ version: 'r1', negation: false },
                                         { version: 'r1', negation: true },
                                         { version: 'r2', negation: false },
                                         { version: 'r2cql', negation: false }]
        hqmf_oids = version_negation_combinations.collect do |obj|
          template_id_by_definition_and_status(definition, status, obj[:negation], obj[:version])
        end
        hqmf_oids
      end
    end
  end
end