# frozen_string_literal: true

module FriendlyShipping
  module Services
    class UspsInternational
      class ParsePackageRate
        # USPS returns all the info about a rate in a long string with a bit of gibberish.
        ESCAPING_AND_SYMBOLS = /<\S*>/.freeze

        # At the beginning of the long String, USPS keeps a copy of its own name. We know we're dealing with
        # them though, so we can filter that out, too.
        LEADING_USPS = /^USPS /.freeze

        # This combines all the things we want to filter out.
        SERVICE_NAME_SUBSTITUTIONS = /#{ESCAPING_AND_SYMBOLS}|#{LEADING_USPS}/.freeze

        # Often we get a multitude of rates for the same service given some combination of
        # Box type and (see below) and "Hold for Pickup" service. This creates a regular expression
        # with groups named after the keys from the `Usps::CONTAINERS` constant.
        # Unfortunately, the keys don't correspond directly to the codes we use when serializing the
        # request.
        # The tags used in the rate node that we get information from.
        SERVICE_CODE_TAG = 'ID'
        SERVICE_NAME_TAG = 'SvcDescription'
        RATE_TAG = 'Postage'
        COMMERCIAL_RATE_TAG = 'CommercialPostage'
        COMMERCIAL_PLUS_RATE_TAG = 'CommercialPlusPostage'
        CURRENCY = Money::Currency.new('USD').freeze

        class << self
          def call(rate_node, package, package_options)
            # "A mail class identifier for the postage returned. Not necessarily unique within a <Package/>."
            # (from the USPS docs). We save this on the data Hash, but do not use it for identifying shipping methods.
            service_code = rate_node.attributes[SERVICE_CODE_TAG].value

            # The long string discussed above.
            service_name = rate_node.at(SERVICE_NAME_TAG).text

            delivery_guarantee = rate_node.at('GuaranteeAvailability')&.text
            delivery_commitment = rate_node.at('SvcCommitments')&.text

            # Clean up the long string
            service_name.gsub!(SERVICE_NAME_SUBSTITUTIONS, '')

            commercial_rate_requested_or_rate_is_zero = package_options.commercial_pricing || rate_node.at(RATE_TAG).text.to_d.zero?
            commercial_rate_available = rate_node.at(COMMERCIAL_RATE_TAG) || rate_node.at(COMMERCIAL_PLUS_RATE_TAG)

            rate_value =
              if commercial_rate_requested_or_rate_is_zero && commercial_rate_available
                commercial_rate = rate_node.at(COMMERCIAL_RATE_TAG)&.text.to_d
                commercial_rate.zero? ? rate_node.at(COMMERCIAL_PLUS_RATE_TAG).text.to_d : commercial_rate
              else
                rate_node.at(RATE_TAG).text.to_d
              end

            # The rate expressed as a RubyMoney objext
            rate = Money.new(rate_value * CURRENCY.subunit_to_unit, CURRENCY)

            # Which shipping method does this rate belong to? We first try to match a rate to a shipping method
            shipping_method = SHIPPING_METHODS.find { |sm| sm.service_code == service_code }

            # Combine all the gathered information in a FriendlyShipping::Rate object.
            # Careful: This rate is only for one package within the shipment, and we get multiple
            # rates per package for the different shipping method/box/hold for pickup combinations.
            FriendlyShipping::Rate.new(
              shipping_method: shipping_method,
              amounts: { package.id => rate },
              data: {
                package: package,
                delivery_commitment: delivery_commitment,
                delivery_guarantee: delivery_guarantee,
                full_mail_service: service_name,
                service_code: service_code,
              }
            )
          end
        end
      end
    end
  end
end