module ActiveMerchant #:nodoc:
  module Billing #:nodoc:
    module Integrations #:nodoc:
      module Pizza
        module Notification

          # A helper method to parse the raw post of the request & return
          # the right Notification subclass based on the sender id.
          def self.get_notification(http_raw_data)
            params = ActiveMerchant::Billing::Integrations::Notification.new(http_raw_data).params
            Pizza.get_class(params['VK_SND_ID'])::Notification.new(params)
          end

          def bank_signature_valid?(bank_signature, service_msg_number, sigparams)
            self.class.parent.get_bank_public_key.verify(OpenSSL::Digest::SHA1.new, bank_signature, generate_data_string(service_msg_number, sigparams))
          end

          def complete?
            params['VK_SERVICE'] == '1101'
          end

          def currency
            params['VK_CURR']
          end

          # The order id we passed to the form helper.
          def item_id
            params['VK_STAMP']
          end

          def transaction_id
            params['VK_T_NO']
          end

          # When was this payment received by the client.
          # We're expecting a dd.mm.yyyy format.
          def received_at
            date = params['VK_T_DATE']
            return nil unless date
            day, month, year = *date.split('.').map(&:to_i)
            Date.civil(year, month, day)
          end

          def signature
            Base64.decode64(params['VK_MAC'])
          end

          # The money amount we received, string.
          def gross
            params['VK_AMOUNT']
          end

          # Was this a test transaction?
          def test?
            params['VK_REC_ID'] == 'testvpos'
          end

          # TODO what should be here?
          def status
            complete? ? 'Completed' : 'Failed'
          end

          # If our request was sent automatically by the bank (true) or manually
          # by the user triggering the callback by pressing a "return" button (false).
          def automatic?
            params['VK_AUTO'].upcase == 'Y'
          end

          def success?
            acknowledge && complete?
          end

          # We don't actually acknowledge the notification by making another request ourself,
          # instead, we check the notification by checking the signature that came with the notification.
          # This method has to be called when handling the notification & deciding whether to process the order.
          # Example:
          #
          #   def notify
          #     notify = Notification.new(params)
          #
          #     if notify.acknowledge
          #       ... process order ... if notify.complete?
          #     else
          #       ... log possible hacking attempt ...
          #     end
          def acknowledge
            bank_signature_valid?(signature, params['VK_SERVICE'], params)
          end

          private
          # Take the posted data and move the relevant data into a hash
          # No parsing since we're already expecting a hash.
          def parse(params)
            raise(ArgumentError, 'Need a hash') unless params.is_a?(Hash)
            @params = params
          end
        end
      end
    end
  end
end