# frozen_string_literal: true
# This class loads an authority.
module QaServer
  class AuthorityLoaderService
    class << self
      # Load a QA authority
      # @param authority_name [String] name of the authority to load (e.g. "agrovoc_direct")
      # @param status_log [ScenarioLogger] logger to hold failure information if the authority cannot be loaded
      # @return [Qa::Authorities::LinkedData::GenericAuthority] the instance of the authority that can receive QA requests OR nil if fails to load
      def load(authority_name:, status_log: nil)
        begin
          authority = load_authority(authority_name, status_log)
          return nil if authority.blank?
        rescue Exception => e
          if status_log.present?
            status_log.add(authority_name: authority_name,
                           status: QaServer::ScenarioValidator::FAIL,
                           error_message: "Unable to load authority '#{authority_name}'; cause: #{e.message}")
          end
          return nil
        end
        authority
      end

    private

      def authority_key(authority_name)
        authority_name.upcase.to_sym
      end

      def load_authority(authority_name, status_log)
        authority = Qa::Authorities::LinkedData::GenericAuthority.new(authority_key(authority_name))
        if authority.blank?
          if status_log.present?
            status_log.add(authority_name: authority_name,
                           status: QaServer::ScenarioValidator::FAIL,
                           error_message: "Unable to load authority '#{authority_name}'; cause: UNKNOWN")
          end
          return nil
        end
        authority
      end
    end
  end
end