Rename Payments to PaymentOrders

app/models/payment_orders/bank_link.rb

@@ -0,0 +1,146 @@
+module PaymentOrders
+  class BankLink < Base
+    BANK_LINK_VERSION = '008'
+
+    NEW_TRANSACTION_SERVICE_NUMBER    = '1012'
+    SUCCESSFUL_PAYMENT_SERVICE_NUMBER = '1111'
+    CANCELLED_PAYMENT_SERVICE_NUMBER  = '1911'
+
+    NEW_MESSAGE_KEYS     = %w(VK_SERVICE VK_VERSION VK_SND_ID VK_STAMP VK_AMOUNT
+                              VK_CURR VK_REF VK_MSG VK_RETURN VK_CANCEL
+                              VK_DATETIME).freeze
+    SUCCESS_MESSAGE_KEYS = %w(VK_SERVICE VK_VERSION VK_SND_ID VK_REC_ID VK_STAMP
+                              VK_T_NO VK_AMOUNT VK_CURR VK_REC_ACC VK_REC_NAME
+                              VK_SND_ACC VK_SND_NAME VK_REF VK_MSG
+                              VK_T_DATETIME).freeze
+    CANCEL_MESSAGE_KEYS  = %w(VK_SERVICE VK_VERSION VK_SND_ID VK_REC_ID VK_STAMP
+                              VK_REF VK_MSG).freeze
+
+    def form_fields
+      hash = {}
+      hash["VK_SERVICE"]  = NEW_TRANSACTION_SERVICE_NUMBER
+      hash["VK_VERSION"]  = BANK_LINK_VERSION
+      hash["VK_SND_ID"]   = seller_account
+      hash["VK_STAMP"]    = invoice.number
+      hash["VK_AMOUNT"]   = number_with_precision(invoice.total, precision: 2, separator: ".")
+      hash["VK_CURR"]     = invoice.currency
+      hash["VK_REF"]      = ""
+      hash["VK_MSG"]      = invoice.order
+      hash["VK_RETURN"]   = return_url
+      hash["VK_CANCEL"]   = return_url
+      hash["VK_DATETIME"] = Time.zone.now.strftime("%Y-%m-%dT%H:%M:%S%z")
+      hash["VK_MAC"]      = calc_mac(hash)
+      hash["VK_ENCODING"] = "UTF-8"
+      hash["VK_LANG"]     = "ENG"
+      hash
+    end
+
+    def valid_response_from_intermediary?
+      return false unless response
+
+      case response["VK_SERVICE"]
+      when SUCCESSFUL_PAYMENT_SERVICE_NUMBER
+        valid_successful_transaction?
+      when CANCELLED_PAYMENT_SERVICE_NUMBER
+        valid_cancel_notice?
+      else
+        false
+      end
+    end
+
+    def complete_transaction
+      return unless valid_successful_transaction?
+
+      transaction = BankTransaction.find_by(
+        description: invoice.order,
+        currency: invoice.currency,
+        iban: invoice.seller_iban
+      )
+
+      transaction.sum             = response['VK_AMOUNT']
+      transaction.bank_reference  = response['VK_T_NO']
+      transaction.buyer_bank_code = response["VK_SND_ID"]
+      transaction.buyer_iban      = response["VK_SND_ACC"]
+      transaction.buyer_name      = response["VK_SND_NAME"]
+      transaction.paid_at         = Time.parse(response["VK_T_DATETIME"])
+
+      transaction.save!
+      transaction.autobind_invoice
+    end
+
+    def settled_payment?
+      response["VK_SERVICE"] == SUCCESSFUL_PAYMENT_SERVICE_NUMBER
+    end
+
+    private
+
+    def valid_successful_transaction?
+      valid_success_notice? && valid_amount? && valid_currency?
+    end
+
+    def valid_cancel_notice?
+      valid_mac?(response, CANCEL_MESSAGE_KEYS)
+    end
+
+    def valid_success_notice?
+      valid_mac?(response, SUCCESS_MESSAGE_KEYS)
+    end
+
+    def valid_amount?
+      source = number_with_precision(
+        BigDecimal.new(response["VK_AMOUNT"]), precision: 2, separator: "."
+      )
+      target = number_with_precision(
+        invoice.total, precision: 2, separator: "."
+      )
+
+      source == target
+    end
+
+    def valid_currency?
+      invoice.currency == response["VK_CURR"]
+    end
+
+    def sign(data)
+      private_key = OpenSSL::PKey::RSA.new(File.read(seller_certificate))
+      signed_data = private_key.sign(OpenSSL::Digest::SHA1.new, data)
+      signed_data = Base64.encode64(signed_data).gsub(/\n|\r/, '')
+      signed_data
+    end
+
+    def calc_mac(fields)
+      pars = NEW_MESSAGE_KEYS
+      data = pars.map { |element| prepend_size(fields[element]) }.join
+      sign(data)
+    end
+
+    def valid_mac?(hash, keys)
+      data = keys.map { |element| prepend_size(hash[element]) }.join
+      verify_mac(data, hash["VK_MAC"])
+    end
+
+    def verify_mac(data, mac)
+      bank_public_key = OpenSSL::X509::Certificate.new(File.read(bank_certificate)).public_key
+      bank_public_key.verify(OpenSSL::Digest::SHA1.new, Base64.decode64(mac), data)
+    end
+
+    def prepend_size(value)
+      value = (value || "").to_s.strip
+      string = ""
+      string << format("%03i", value.size)
+      string << value
+    end
+
+    def seller_account
+      ENV["payments_#{type}_seller_account"]
+    end
+
+    def seller_certificate
+      ENV["payments_#{type}_seller_private"]
+    end
+
+    def bank_certificate
+      ENV["payments_#{type}_bank_certificate"]
+    end
+  end
+end