module ActiveMerchant #:nodoc:
  module Billing #:nodoc:
    # For more information on the Authorize.Net Gateway please visit their {Integration Center}[http://developer.authorize.net/]
    #
    # The login and password are not the username and password you use to
    # login to the Authorize.Net Merchant Interface. Instead, you will
    # use the API Login ID as the login and Transaction Key as the
    # password.
    #
    # ==== How to Get Your API Login ID and Transaction Key
    #
    # 1. Log into the Merchant Interface
    # 2. Select Settings from the Main Menu
    # 3. Click on API Login ID and Transaction Key in the Security section
    # 4. Type in the answer to the secret question configured on setup
    # 5. Click Submit
    #
    # ==== Automated Recurring Billing (ARB)
    #
    # Automated Recurring Billing (ARB) is an optional service for submitting and managing recurring, or subscription-based, transactions.
    #
    # To use recurring, update_recurring, cancel_recurring and status_recurring ARB must be enabled for your account.
    #
    # Information about ARB is available on the {Authorize.Net website}[http://www.authorize.net/solutions/merchantsolutions/merchantservices/automatedrecurringbilling/].
    # Information about the ARB API is available at the {Authorize.Net Integration Center}[http://developer.authorize.net/]
    class AuthorizeNetGateway < Gateway
      API_VERSION = '3.1'

      class_attribute :arb_test_url, :arb_live_url

      self.test_url = "https://test.authorize.net/gateway/transact.dll"
      self.live_url = "https://secure.authorize.net/gateway/transact.dll"

      self.arb_test_url = 'https://apitest.authorize.net/xml/v1/request.api'
      self.arb_live_url = 'https://api.authorize.net/xml/v1/request.api'

      class_attribute :duplicate_window

      APPROVED, DECLINED, ERROR, FRAUD_REVIEW = 1, 2, 3, 4

      RESPONSE_CODE, RESPONSE_REASON_CODE, RESPONSE_REASON_TEXT = 0, 2, 3
      AVS_RESULT_CODE, TRANSACTION_ID, CARD_CODE_RESPONSE_CODE  = 5, 6, 38

      self.default_currency = 'USD'

      self.supported_countries = ['US', 'CA', 'GB']
      self.supported_cardtypes = [:visa, :master, :american_express, :discover, :diners_club, :jcb]
      self.homepage_url = 'http://www.authorize.net/'
      self.display_name = 'Authorize.Net'

      CARD_CODE_ERRORS = %w( N S )
      AVS_ERRORS = %w( A E N R W Z )
      AVS_REASON_CODES = %w(27 45)

      AUTHORIZE_NET_ARB_NAMESPACE = 'AnetApi/xml/v1/schema/AnetApiSchema.xsd'

      RECURRING_ACTIONS = {
        :create => 'ARBCreateSubscription',
        :update => 'ARBUpdateSubscription',
        :cancel => 'ARBCancelSubscription',
        :status => 'ARBGetSubscriptionStatus'
      }

      # Creates a new AuthorizeNetGateway
      #
      # The gateway requires that a valid login and password be passed
      # in the +options+ hash.
      #
      # ==== Options
      #
      # * <tt>:login</tt> -- The Authorize.Net API Login ID (REQUIRED)
      # * <tt>:password</tt> -- The Authorize.Net Transaction Key. (REQUIRED)
      # * <tt>:test</tt> -- +true+ or +false+. If true, perform transactions against the test server.
      #   Otherwise, perform transactions against the production server.
      def initialize(options = {})
        requires!(options, :login, :password)
        super
      end

      # Performs an authorization, which reserves the funds on the customer's credit card, but does not
      # charge the card.
      #
      # ==== Parameters
      #
      # * <tt>money</tt> -- The amount to be authorized as an Integer value in cents.
      # * <tt>paysource</tt> -- The CreditCard or Check details for the transaction.
      # * <tt>options</tt> -- A hash of optional parameters.
      def authorize(money, paysource, options = {})
        post = {}
        add_currency_code(post, money, options)
        add_invoice(post, options)
        add_payment_source(post, paysource, options)
        add_address(post, options)
        add_customer_data(post, options)
        add_duplicate_window(post)

        commit('AUTH_ONLY', money, post)
      end

      # Perform a purchase, which is essentially an authorization and capture in a single operation.
      #
      # ==== Parameters
      #
      # * <tt>money</tt> -- The amount to be purchased as an Integer value in cents.
      # * <tt>paysource</tt> -- The CreditCard or Check details for the transaction.
      # * <tt>options</tt> -- A hash of optional parameters.
      def purchase(money, paysource, options = {})
        post = {}
        add_currency_code(post, money, options)
        add_invoice(post, options)
        add_payment_source(post, paysource, options)
        add_address(post, options)
        add_customer_data(post, options)
        add_duplicate_window(post)

        commit('AUTH_CAPTURE', money, post)
      end

      # Captures the funds from an authorized transaction.
      #
      # ==== Parameters
      #
      # * <tt>money</tt> -- The amount to be captured as an Integer value in cents.
      # * <tt>authorization</tt> -- The authorization returned from the previous authorize request.
      def capture(money, authorization, options = {})
        post = {:trans_id => authorization}
        add_customer_data(post, options)
        add_invoice(post, options)
        commit('PRIOR_AUTH_CAPTURE', money, post)
      end

      # Void a previous transaction
      #
      # ==== Parameters
      #
      # * <tt>authorization</tt> - The authorization returned from the previous authorize request.
      def void(authorization, options = {})
        post = {:trans_id => authorization}
        add_duplicate_window(post)
        commit('VOID', nil, post)
      end

      # Refund a transaction.
      #
      # This transaction indicates to the gateway that
      # money should flow from the merchant to the customer.
      #
      # ==== Parameters
      #
      # * <tt>money</tt> -- The amount to be credited to the customer as an Integer value in cents.
      # * <tt>identification</tt> -- The ID of the original transaction against which the refund is being issued.
      # * <tt>options</tt> -- A hash of parameters.
      #
      # ==== Options
      #
      # * <tt>:card_number</tt> -- The credit card number the refund is being issued to. (REQUIRED)
      #   You can either pass the last four digits of the card number or the full card number.
      # * <tt>:first_name</tt> -- The first name of the account being refunded.
      # * <tt>:last_name</tt> -- The last name of the account being refunded.
      # * <tt>:zip</tt> -- The postal code of the account being refunded.
      def refund(money, identification, options = {})
        requires!(options, :card_number)

        post = { :trans_id => identification,
                 :card_num => options[:card_number]
               }

        post[:first_name] = options[:first_name] if options[:first_name]
        post[:last_name] = options[:last_name] if options[:last_name]
        post[:zip] = options[:zip] if options[:zip]

        add_invoice(post, options)
        add_duplicate_window(post)

        commit('CREDIT', money, post)
      end

      def credit(money, identification, options = {})
        deprecated CREDIT_DEPRECATION_MESSAGE
        refund(money, identification, options)
      end

      # Create a recurring payment.
      #
      # This transaction creates a new Automated Recurring Billing (ARB) subscription. Your account must have ARB enabled.
      #
      # ==== Parameters
      #
      # * <tt>money</tt> -- The amount to be charged to the customer at each interval as an Integer value in cents.
      # * <tt>creditcard</tt> -- The CreditCard details for the transaction.
      # * <tt>options</tt> -- A hash of parameters.
      #
      # ==== Options
      #
      # * <tt>:interval</tt> -- A hash containing information about the interval of time between payments. Must
      #   contain the keys <tt>:length</tt> and <tt>:unit</tt>. <tt>:unit</tt> can be either <tt>:months</tt> or <tt>:days</tt>.
      #   If <tt>:unit</tt> is <tt>:months</tt> then <tt>:length</tt> must be an integer between 1 and 12 inclusive.
      #   If <tt>:unit</tt> is <tt>:days</tt> then <tt>:length</tt> must be an integer between 7 and 365 inclusive.
      #   For example, to charge the customer once every three months the hash would be
      #   +:interval => { :unit => :months, :length => 3 }+ (REQUIRED)
      # * <tt>:duration</tt> -- A hash containing keys for the <tt>:start_date</tt> the subscription begins (also the date the
      #   initial billing occurs) and the total number of billing <tt>:occurences</tt> or payments for the subscription. (REQUIRED)
      def recurring(money, creditcard, options={})
        requires!(options, :interval, :duration, :billing_address)
        requires!(options[:interval], :length, [:unit, :days, :months])
        requires!(options[:duration], :start_date, :occurrences)
        requires!(options[:billing_address], :first_name, :last_name)

        options[:credit_card] = creditcard
        options[:amount] = money

        request = build_recurring_request(:create, options)
        recurring_commit(:create, request)
      end

      # Update a recurring payment's details.
      #
      # This transaction updates an existing Automated Recurring Billing (ARB) subscription. Your account must have ARB enabled
      # and the subscription must have already been created previously by calling +recurring()+. The ability to change certain
      # details about a recurring payment is dependent on transaction history and cannot be determined until after calling
      # +update_recurring()+. See the ARB XML Guide for such conditions.
      #
      # ==== Parameters
      #
      # * <tt>options</tt> -- A hash of parameters.
      #
      # ==== Options
      #
      # * <tt>:subscription_id</tt> -- A string containing the <tt>:subscription_id</tt> of the recurring payment already in place
      #   for a given credit card. (REQUIRED)
      def update_recurring(options={})
        requires!(options, :subscription_id)
        request = build_recurring_request(:update, options)
        recurring_commit(:update, request)
      end

      # Cancel a recurring payment.
      #
      # This transaction cancels an existing Automated Recurring Billing (ARB) subscription. Your account must have ARB enabled
      # and the subscription must have already been created previously by calling recurring()
      #
      # ==== Parameters
      #
      # * <tt>subscription_id</tt> -- A string containing the +subscription_id+ of the recurring payment already in place
      #   for a given credit card. (REQUIRED)
      def cancel_recurring(subscription_id)
        request = build_recurring_request(:cancel, :subscription_id => subscription_id)
        recurring_commit(:cancel, request)
      end

      # Get Subscription Status of a recurring payment.
      #
      # This transaction gets the status of an existing Automated Recurring Billing (ARB) subscription. Your account must have ARB enabled.
      #
      # ==== Parameters
      #
      # * <tt>subscription_id</tt> -- A string containing the +subscription_id+ of the recurring payment already in place
      #   for a given credit card. (REQUIRED)
      def status_recurring(subscription_id)
        request = build_recurring_request(:status, :subscription_id => subscription_id)
        recurring_commit(:status, request)
      end

      private

      def commit(action, money, parameters)
        parameters[:amount] = amount(money) unless action == 'VOID'

        # Only activate the test_request when the :test option is passed in
        parameters[:test_request] = @options[:test] ? 'TRUE' : 'FALSE'

        url = test? ? self.test_url : self.live_url
        data = ssl_post url, post_data(action, parameters)

        response          = parse(data)
        response[:action] = action

        message = message_from(response)

        # Return the response. The authorization can be taken out of the transaction_id
        # Test Mode on/off is something we have to parse from the response text.
        # It usually looks something like this
        #
        #   (TESTMODE) Successful Sale
        test_mode = test? || message =~ /TESTMODE/

        Response.new(success?(response), message, response,
          :test => test_mode,
          :authorization => response[:transaction_id],
          :fraud_review => fraud_review?(response),
          :avs_result => { :code => response[:avs_result_code] },
          :cvv_result => response[:card_code]
        )
      end

      def success?(response)
        response[:response_code] == APPROVED
      end

      def fraud_review?(response)
        response[:response_code] == FRAUD_REVIEW
      end

      def parse(body)
        fields = split(body)

        results = {
          :response_code => fields[RESPONSE_CODE].to_i,
          :response_reason_code => fields[RESPONSE_REASON_CODE],
          :response_reason_text => fields[RESPONSE_REASON_TEXT],
          :avs_result_code => fields[AVS_RESULT_CODE],
          :transaction_id => fields[TRANSACTION_ID],
          :card_code => fields[CARD_CODE_RESPONSE_CODE]
        }
        results
      end

      def post_data(action, parameters = {})
        post = {}

        post[:version]        = API_VERSION
        post[:login]          = @options[:login]
        post[:tran_key]       = @options[:password]
        post[:relay_response] = "FALSE"
        post[:type]           = action
        post[:delim_data]     = "TRUE"
        post[:delim_char]     = ","
        post[:encap_char]     = "$"
        post[:solution_ID]    = application_id if application_id.present? && application_id != "ActiveMerchant"

        request = post.merge(parameters).collect { |key, value| "x_#{key}=#{CGI.escape(value.to_s)}" }.join("&")
        request
      end

      def add_currency_code(post, money, options)
        post[:currency_code] = options[:currency] || currency(money)
      end

      def add_invoice(post, options)
        post[:invoice_num] = options[:order_id]
        post[:description] = options[:description]
      end

      def add_creditcard(post, creditcard)
        post[:card_num]   = creditcard.number
        post[:card_code]  = creditcard.verification_value if creditcard.verification_value?
        post[:exp_date]   = expdate(creditcard)
        post[:first_name] = creditcard.first_name
        post[:last_name]  = creditcard.last_name
      end

      def add_payment_source(params, source, options={})
        if card_brand(source) == "check"
          add_check(params, source, options)
        else
          add_creditcard(params, source)
        end
      end

      def add_check(post, check, options)
        post[:method] = "ECHECK"
        post[:bank_name] = check.bank_name
        post[:bank_aba_code] = check.routing_number
        post[:bank_acct_num] = check.account_number
        post[:bank_acct_type] = check.account_type
        post[:echeck_type] = "WEB"
        post[:bank_acct_name] = check.name
        post[:bank_check_number] = check.number if check.number.present?
        post[:recurring_billing] = (options[:recurring] ? "TRUE" : "FALSE")
      end

      def add_customer_data(post, options)
        if options.has_key? :email
          post[:email] = options[:email]
          post[:email_customer] = false
        end

        if options.has_key? :customer
          post[:cust_id] = options[:customer] if Float(options[:customer]) rescue nil
        end

        if options.has_key? :ip
          post[:customer_ip] = options[:ip]
        end
      end

      # x_duplicate_window won't be sent by default, because sending it changes the response.
      # "If this field is present in the request with or without a value, an enhanced duplicate transaction response will be sent."
      # (as of 2008-12-30) http://www.authorize.net/support/AIM_guide_SCC.pdf
      def add_duplicate_window(post)
        unless duplicate_window.nil?
          post[:duplicate_window] = duplicate_window
        end
      end

      def add_address(post, options)
        if address = options[:billing_address] || options[:address]
          post[:address] = address[:address1].to_s
          post[:company] = address[:company].to_s
          post[:phone]   = address[:phone].to_s
          post[:zip]     = address[:zip].to_s
          post[:city]    = address[:city].to_s
          post[:country] = address[:country].to_s
          post[:state]   = address[:state].blank?  ? 'n/a' : address[:state]
        end

        if address = options[:shipping_address]
          post[:ship_to_first_name] = address[:first_name].to_s
          post[:ship_to_last_name] = address[:last_name].to_s
          post[:ship_to_address] = address[:address1].to_s
          post[:ship_to_company] = address[:company].to_s
          post[:ship_to_phone]   = address[:phone].to_s
          post[:ship_to_zip]     = address[:zip].to_s
          post[:ship_to_city]    = address[:city].to_s
          post[:ship_to_country] = address[:country].to_s
          post[:ship_to_state]   = address[:state].blank?  ? 'n/a' : address[:state]
        end
      end

      # Make a ruby type out of the response string
      def normalize(field)
        case field
        when "true"   then true
        when "false"  then false
        when ""       then nil
        when "null"   then nil
        else field
        end
      end

      def message_from(results)
        if results[:response_code] == DECLINED
          return CVVResult.messages[ results[:card_code] ] if CARD_CODE_ERRORS.include?(results[:card_code])
          if AVS_REASON_CODES.include?(results[:response_reason_code]) && AVS_ERRORS.include?(results[:avs_result_code])
            return AVSResult.messages[ results[:avs_result_code] ]
          end
        end

        (results[:response_reason_text] ? results[:response_reason_text].chomp('.') : '')
      end

      def expdate(creditcard)
        year  = sprintf("%.4i", creditcard.year)
        month = sprintf("%.2i", creditcard.month)

        "#{month}#{year[-2..-1]}"
      end

      def split(response)
        response[1..-2].split(/\$,\$/)
      end

      # ARB

      # Builds recurring billing request
      def build_recurring_request(action, options = {})
        unless RECURRING_ACTIONS.include?(action)
          raise StandardError, "Invalid Automated Recurring Billing Action: #{action}"
        end

        xml = Builder::XmlMarkup.new(:indent => 2)
        xml.instruct!(:xml, :version => '1.0', :encoding => 'utf-8')
        xml.tag!("#{RECURRING_ACTIONS[action]}Request", :xmlns => AUTHORIZE_NET_ARB_NAMESPACE) do
          add_arb_merchant_authentication(xml)
          # Merchant-assigned reference ID for the request
          xml.tag!('refId', options[:ref_id]) if options[:ref_id]
          send("build_arb_#{action}_subscription_request", xml, options)
        end
      end

      # Contains the merchant’s payment gateway account authentication information
      def add_arb_merchant_authentication(xml)
        xml.tag!('merchantAuthentication') do
          xml.tag!('name', @options[:login])
          xml.tag!('transactionKey', @options[:password])
        end
      end

      # Builds body for ARBCreateSubscriptionRequest
      def build_arb_create_subscription_request(xml, options)
        # Subscription
        add_arb_subscription(xml, options)

        xml.target!
      end

      # Builds body for ARBUpdateSubscriptionRequest
      def build_arb_update_subscription_request(xml, options)
        xml.tag!('subscriptionId', options[:subscription_id])
        # Adds Subscription
        add_arb_subscription(xml, options)

        xml.target!
      end

      # Builds body for ARBCancelSubscriptionRequest
      def build_arb_cancel_subscription_request(xml, options)
        xml.tag!('subscriptionId', options[:subscription_id])

        xml.target!
      end

      # Builds body for ARBGetSubscriptionStatusRequest
      def build_arb_status_subscription_request(xml, options)
        xml.tag!('subscriptionId', options[:subscription_id])

        xml.target!
      end

      # Adds subscription information
      def add_arb_subscription(xml, options)
        xml.tag!('subscription') do
          # Merchant-assigned name for the subscription (optional)
          xml.tag!('name', options[:subscription_name]) if options[:subscription_name]
          # Contains information about the payment schedule
          add_arb_payment_schedule(xml, options)
          # The amount to be billed to the customer
          # for each payment in the subscription
          xml.tag!('amount', amount(options[:amount])) if options[:amount]
          if trial = options[:trial]
            # The amount to be charged for each payment during a trial period (conditional)
            xml.tag!('trialAmount', amount(trial[:amount])) if trial[:amount]
          end
          # Contains either the customer’s credit card
          # or bank account payment information
          add_arb_payment(xml, options)
          # Contains order information (optional)
          add_arb_order(xml, options)
          # Contains information about the customer
          add_arb_customer(xml, options)
          # Contains the customer's billing address information
          add_arb_address(xml, 'billTo', options[:billing_address])
          # Contains the customer's shipping address information (optional)
          add_arb_address(xml, 'shipTo', options[:shipping_address])
        end
      end

      # Adds information about the interval of time between payments
      def add_arb_interval(xml, options)
        interval = options[:interval]
        return unless interval
        xml.tag!('interval') do
          # The measurement of time, in association with the Interval Unit,
          # that is used to define the frequency of the billing occurrences
          xml.tag!('length', interval[:length])
          # The unit of time, in association with the Interval Length,
          # between each billing occurrence
          xml.tag!('unit', interval[:unit].to_s)
        end
      end

      # Adds information about the subscription duration
      def add_arb_duration(xml, options)
        duration = options[:duration]
        return unless duration
        # The date the subscription begins
        # (also the date the initial billing occurs)
        xml.tag!('startDate', duration[:start_date]) if duration[:start_date]
        # Number of billing occurrences or payments for the subscription
        xml.tag!('totalOccurrences', duration[:occurrences]) if duration[:occurrences]
      end

      def add_arb_payment_schedule(xml, options)
        return unless options[:interval] || options[:duration]
        xml.tag!('paymentSchedule') do
          # Contains information about the interval of time between payments
          add_arb_interval(xml, options)
          add_arb_duration(xml, options)
          if trial = options[:trial]
            # Number of billing occurrences or payments in the trial period (optional)
            xml.tag!('trialOccurrences', trial[:occurrences]) if trial[:occurrences]
          end
        end
      end

      # Adds customer's credit card or bank account payment information
      def add_arb_payment(xml, options)
        return unless options[:credit_card] || options[:bank_account]
        xml.tag!('payment') do
          # Contains the customer’s credit card information
          add_arb_credit_card(xml, options)
          # Contains the customer’s bank account information
          add_arb_bank_account(xml, options)
        end
      end

      # Adds customer’s credit card information
      # Note: This element should only be included
      # when the payment method is credit card.
      def add_arb_credit_card(xml, options)
        credit_card = options[:credit_card]
        return unless credit_card
        xml.tag!('creditCard') do
          # The credit card number used for payment of the subscription
          xml.tag!('cardNumber', credit_card.number)
          # The expiration date of the credit card used for the subscription
          xml.tag!('expirationDate', arb_expdate(credit_card))
        end
      end

      # Adds customer’s bank account information
      # Note: This element should only be included
      # when the payment method is bank account.
      def add_arb_bank_account(xml, options)
        bank_account = options[:bank_account]
        return unless bank_account
        xml.tag!('bankAccount') do
          # The type of bank account used for payment of the subscription
          xml.tag!('accountType', bank_account[:account_type])
          # The routing number of the customer’s bank
          xml.tag!('routingNumber', bank_account[:routing_number])
          # The bank account number used for payment of the subscription
          xml.tag!('accountNumber', bank_account[:account_number])
          # The full name of the individual associated
          # with the bank account number
          xml.tag!('nameOfAccount', bank_account[:name_of_account])
          # The full name of the individual associated
          # with the bank account number (optional)
          xml.tag!('bankName', bank_account[:bank_name]) if bank_account[:bank_name]
          # The type of electronic check transaction used for the subscription
          xml.tag!('echeckType', bank_account[:echeck_type])
        end
      end

      # Adds order information (optional)
      def add_arb_order(xml, options)
        order = options[:order]
        return unless order
        xml.tag!('order') do
          # Merchant-assigned invoice number for the subscription (optional)
          xml.tag!('invoiceNumber', order[:invoice_number])
          # Description of the subscription (optional)
          xml.tag!('description', order[:description])
        end
      end

      # Adds information about the customer
      def add_arb_customer(xml, options)
        customer = options[:customer]
        return unless customer
        xml.tag!('customer') do
          xml.tag!('type', customer[:type]) if customer[:type]
          xml.tag!('id', customer[:id]) if customer[:id]
          xml.tag!('email', customer[:email]) if customer[:email]
          xml.tag!('phoneNumber', customer[:phone_number]) if customer[:phone_number]
          xml.tag!('faxNumber', customer[:fax_number]) if customer[:fax_number]
          add_arb_drivers_license(xml, options)
          xml.tag!('taxId', customer[:tax_id]) if customer[:tax_id]
        end
      end

      # Adds the customer's driver's license information (conditional)
      def add_arb_drivers_license(xml, options)
        return unless customer = options[:customer]
        return unless drivers_license = customer[:drivers_license]
        xml.tag!('driversLicense') do
          # The customer's driver's license number
          xml.tag!('number', drivers_license[:number])
          # The customer's driver's license state
          xml.tag!('state', drivers_license[:state])
          # The customer's driver's license date of birth
          xml.tag!('dateOfBirth', drivers_license[:date_of_birth])
        end
      end

      # Adds address information
      def add_arb_address(xml, container_name, address)
        return if address.blank?
        xml.tag!(container_name) do
          xml.tag!('firstName', address[:first_name])
          xml.tag!('lastName', address[:last_name])
          xml.tag!('company', address[:company])
          xml.tag!('address', address[:address1])
          xml.tag!('city', address[:city])
          xml.tag!('state', address[:state])
          xml.tag!('zip', address[:zip])
          xml.tag!('country', address[:country])
        end
      end

      def arb_expdate(credit_card)
        sprintf('%04d-%02d', credit_card.year, credit_card.month)
      end

      def recurring_commit(action, request)
        url = test? ? arb_test_url : arb_live_url
        xml = ssl_post(url, request, "Content-Type" => "text/xml")

        response = recurring_parse(action, xml)

        message = response[:message] || response[:text]
        test_mode = test? || message =~ /Test Mode/
        success = response[:result_code] == 'Ok'

        Response.new(success, message, response,
          :test => test_mode,
          :authorization => response[:subscription_id]
        )
      end

     def recurring_parse(action, xml)
        response = {}
        xml = REXML::Document.new(xml)
        root = REXML::XPath.first(xml, "//#{RECURRING_ACTIONS[action]}Response") ||
               REXML::XPath.first(xml, "//ErrorResponse")
        if root
          root.elements.to_a.each do |node|
            recurring_parse_element(response, node)
          end
        end

        response
      end

      def recurring_parse_element(response, node)
        if node.has_elements?
          node.elements.each{|e| recurring_parse_element(response, e) }
        else
          response[node.name.underscore.to_sym] = node.text
        end
      end
    end
  end
end
