module ActiveMerchant #:nodoc:
  module Billing #:nodoc:
    class CardStreamGateway < Gateway
      self.test_url = self.live_url = 'https://gateway.cardstream.com/direct/'
      self.money_format = :cents
      self.default_currency = 'GBP'
      self.supported_countries = ['GB', 'USD', 'EUR', 'CHF', 'SEK', 'SGD', 'NOK', 'JPY', 'ICK', 'HKD', 'DKK', 'CZK', 'CAD', 'AUD']
      self.supported_cardtypes = [:visa, :master, :american_express, :diners_club, :discover, :jcb, :maestro, :solo, :switch]
      self.homepage_url = 'http://www.cardstream.com/'
      self.display_name = 'CardStream'

      CURRENCY_CODES = {
        "AUD" => '036',
        "CAD" => '124',
        "CZK" => '203',
        "DKK" => '208',
        "HKD" => '344',
        "ICK" => '352',
        "JPY" => '392',
        "NOK" => '578',
        "SGD" => '702',
        "SEK" => '752',
        "CHF" => '756',
        "GBP" => '826',
        "USD" => '840',
        "EUR" => '978'
      }

      CVV_CODE = {
        '0' => 'U',
        '1' => 'P',
        '2' => 'M',
        '4' => 'N'
      }

      # 0 - No additional information available.
      # 1 - Postcode not checked.
      # 2 - Postcode matched.
      # 4 - Postcode not matched.
      # 8 - Postcode partially matched.
      AVS_POSTAL_MATCH = {
        "0" => nil,
        "1" => nil,
        "2" => "Y",
        "4" => "N",
        "8" => "N"
      }

      # 0 - No additional information available.
      # 1 - Address numeric not checked.
      # 2 - Address numeric matched.
      # 4 - Address numeric not matched.
      # 8 - Address numeric partially matched.
      AVS_STREET_MATCH = {
        "0" => nil,
        "1" => nil,
        "2" => "Y",
        "4" => "N",
        "8" => "N"
      }

      def initialize(options = {})
        requires!(options, :login, :shared_secret)
        if (options[:threeDSRequired])
          @threeDSRequired = options[:threeDSRequired]
        else
          @threeDSRequired = 'N'
        end
        super
      end

      def authorize(money, creditcard, options = {})
        post = {}
        add_amount(post, money, options)
        add_invoice(post, creditcard, money, options)
        add_creditcard(post, creditcard)
        add_address(post, creditcard, options)
        add_customer_data(post, options)
        commit('PREAUTH', post)
      end

      def purchase(money, creditcard, options = {})
        post = {}
        add_amount(post, money, options)
        add_invoice(post, creditcard, money, options)
        add_creditcard(post, creditcard)
        add_address(post, creditcard, options)
        add_customer_data(post, options)
        commit('SALE', post)
      end

      def capture(money, authorization, options = {})
        post = {}
        add_pair(post, :xref, authorization)
        add_amount(post, money, options)
        commit('SALE', post)
      end

      def refund(money, authorization, options = {})
        post = {}
        add_pair(post, :xref, authorization)
        add_amount(post, money, options)
        commit('REFUND', post)
      end

      def void(authorization, options = {})
        post = {}
        add_pair(post, :xref, authorization)
        commit('REFUND', post)
      end

      private

      def add_amount(post, money, options)
        add_pair(post, :amount, amount(money), :required => true)
        add_pair(post, :currencyCode, currency_code(options[:currency] || currency(money)) || currency_code(self.default_currency))
      end

      def add_customer_data(post, options)
        address = options[:billing_address] || options[:address]
        add_pair(post, :customerPostCode, address[:zip])
        add_pair(post, :customerEmail, options[:email])
        add_pair(post, :customerPhone, options[:phone])
      end

      def add_address(post, creditcard, options)
        address = options[:billing_address] || options[:address]

        return if address.nil?

        add_pair(post, :customerAddress, address[:address1] + " " + (address[:address2].nil? ? "" : address[:address2]))
        add_pair(post, :customerPostCode, address[:zip])
      end

      def add_invoice(post, credit_card, money, options)
        add_pair(post, :transactionUnique, options[:order_id], :required => true)
        add_pair(post, :orderRef, options[:description] || options[:order_id], :required => true)
        if ['american_express', 'diners_club'].include?(card_brand(credit_card).to_s)
          add_pair(post, :item1Quantity, 1)
          add_pair(post, :item1Description, (options[:description] || options[:order_id]).slice(0, 15))
          add_pair(post, :item1GrossValue, amount(money))
        end
      end

      def add_creditcard(post, credit_card)
        add_pair(post, :customerName, credit_card.name, :required => true)
        add_pair(post, :cardNumber, credit_card.number, :required => true)

        add_pair(post, :cardExpiryMonth, format(credit_card.month, :two_digits), :required => true)
        add_pair(post, :cardExpiryYear, format(credit_card.year, :two_digits), :required => true)

        if requires_start_date_or_issue_number?(credit_card)
          add_pair(post, :cardStartMonth, format(credit_card.start_month, :two_digits))
          add_pair(post, :cardStartYear, format(credit_card.start_year, :two_digits))

          add_pair(post, :cardIssueNumber, credit_card.issue_number)
        end

        add_pair(post, :cardCVV, credit_card.verification_value)
      end

      def add_hmac(post)
        result = post.sort.collect { |key, value| "#{key}=#{CGI.escape(value.to_s)}" }.join("&")
        result = Digest::SHA512.hexdigest("#{result}#{@options[:shared_secret]}")

        add_pair(post, :signature, result)
      end

      def parse(body)
        result = {}
        pairs = body.split("&")
        pairs.each do |pair|
          a = pair.split("=")
          # because some values pairs dont have a value
          result[a[0].to_sym] = a[1] == nil ? '' : CGI.unescape(a[1])
        end
        result
      end

      def commit(action, parameters)

        parameters.update(
          :merchantID => @options[:login],
          :action => action,
          :type => '1', #Ecommerce
          :countryCode => self.supported_countries[0],
          :threeDSRequired => @threeDSRequired #Disable 3d secure by default
        )
        # adds a signature to the post hash/array
        add_hmac(parameters)

        response = parse(ssl_post(self.live_url, post_data(action, parameters)))

        Response.new(response[:responseCode] == "0",
                     response[:responseCode] == "0" ? "APPROVED" : response[:responseMessage],
                     response,
                     :test => test?,
                     :authorization => response[:xref],
                     :cvv_result => CVV_CODE[response[:avscv2ResponseCode].to_s[0, 1]],
                     :avs_result => {
                       :postal_match => AVS_POSTAL_MATCH[response[:avscv2ResponseCode].to_s[1, 1]],
                       :street_match => AVS_STREET_MATCH[response[:avscv2ResponseCode].to_s[2, 1]]
                     }
        )
      end

      def currency_code(currency)
        CURRENCY_CODES[currency]
      end

      def post_data(action, parameters = {})
        parameters.collect { |key, value| "#{key}=#{CGI.escape(value.to_s)}" }.join("&")
      end

      def add_pair(post, key, value, options = {})
        post[key] = value if !value.blank? || options[:required]
      end
    end
  end
end