module ActiveMerchant #:nodoc:
  module Billing #:nodoc:
    # For more information on the Metrics Global Payment Gateway, visit the {Metrics Global website}[www.metricsglobal.com].
    # Further documentation on AVS and CVV response codes are available under the support section of the Metrics Global
    # control panel.
    #
    # === Metrics Global Payment Gateway Authentication
    #
    # The login and password for the gateway are the same as the username and password used to log in to the Metrics Global
    # control panel. Contact Metrics Global support to receive credentials for the control panel.
    #
    # === Demo Account
    #
    # There is a public demo account available with the following credentials:
    #
    # Login: demo
    # Password: password
    class MetricsGlobalGateway < Gateway
      API_VERSION = '3.1'

      class_attribute :test_url, :live_url

      self.test_url = 'https://secure.metricsglobalgateway.com/gateway/transact.dll?testing=true'
      self.live_url = 'https://secure.metricsglobalgateway.com/gateway/transact.dll'

      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.supported_countries = ['US']
      self.supported_cardtypes = [:visa, :master, :american_express, :discover, :diners_club, :jcb]
      self.homepage_url = 'http://www.metricsglobal.com'
      self.display_name = 'Metrics Global'

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

      # Creates a new MetricsGlobalGateway
      #
      # The gateway requires that a valid login and password be passed
      # in the +options+ hash.
      #
      # ==== Options
      #
      # * <tt>:login</tt> -- The username required to access the Metrics Global control panel. (REQUIRED)
      # * <tt>:password</tt> -- The password required to access the Metrics Global control panel. (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>creditcard</tt> -- The CreditCard details for the transaction.
      # * <tt>options</tt> -- A hash of optional parameters.
      def authorize(money, creditcard, options = {})
        post = {}
        add_invoice(post, options)
        add_creditcard(post, creditcard)
        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>creditcard</tt> -- The CreditCard details for the transaction.
      # * <tt>options</tt> -- A hash of optional parameters.
      def purchase(money, creditcard, options = {})
        post = {}
        add_invoice(post, options)
        add_creditcard(post, creditcard)
        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)
        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)
      # * <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 = {})
        ActiveMerchant.deprecated CREDIT_DEPRECATION_MESSAGE
        refund(money, identification, options)
      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)

        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

        request = post.merge(parameters).collect { |key, value| "x_#{key}=#{CGI.escape(value.to_s)}" }.join('&')
        request
      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_customer_data(post, options)
        if options.has_key? :email
          post[:email] = options[:email]
          post[:email_customer] = false
        end

        post[:cust_id] = options[:customer] if options.has_key? :customer

        post[:customer_ip] = options[:ip] if options.has_key? :ip
      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."
      def add_duplicate_window(post)
        post[:duplicate_window] = duplicate_window unless duplicate_window.nil?
      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

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

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

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