# frozen_string_literal: true

require 'forwardable'

require_relative '../utils'
require_relative 'response_header'

module BrregGrunndata
  class Client
    # Wrapper around Savon's response
    #
    # Handles unwrapping of XML returned as string
    class Response
      using Utils::StringExt

      extend Forwardable
      def_delegators :@savon_response,
                     :soap_fault?, :http_error?,
                     :body

      # Error raised whenever soap or http error occured so
      # the success? is false but you are still asking for
      # either header or message
      class ResponseFailureError < Error; end

      # Error raised when soap communication was a success,
      # brreg response header indicates success, but for some
      # reason we didn't get any return value as we expected
      #
      # Inspecting #header before calling #message will determin if this error
      # is to be expected.
      #
      # @seehttps://www.brreg.no/produkter-og-tjenester/bestille/tilgang-til-enhetsregisteret-via-web-services/teknisk-beskrivelse-web-services/grunndataws/
      class MessageEmptyError < Error; end

      def initialize(savon_response)
        @savon_response = savon_response
      end

      # Do we have a successful response?
      #
      # We do if:
      #   - We have no HTTP errors or SOAP faults. Savon handles this for us.
      #   - We have a response_header in the document returned from brreg
      #     which indicates success too. I don't know why BRREG needs this in
      #     addition to HTTP status codes and SOAP faults to communicate success
      #     or not :-(
      def success?
        @savon_response.success? && header.success?
      end

      # Returns the header from brreg's response
      #
      # The header contains the overall success of the SOAP operation.
      # The header is something brreg's SOAP API has, so all in all we have
      # http status, soap status and then this status located within the header :(
      def header
        raise ResponseFailureError unless @savon_response.success?

        ResponseHeader.new response_grunndata[:response_header]
      end

      # Returns the header from brreg's response
      #
      # Keys are symbolized.
      #
      # @return Hash
      def message
        raise ResponseFailureError unless success?

        @message ||= response_grunndata[:melding] || raise(MessageEmptyError)
      end

      private

      def response_grunndata
        @response_grunndata ||= parse(body.values.first[:return])[:grunndata]
      end

      def parse(xml)
        parser = Nori.new(
          strip_namespaces: true,
          advanced_typecasting: true,
          convert_tags_to: ->(tag) { tag.underscore.to_sym }
        )

        parser.parse xml
      end
    end
  end
end