lib/banktools-se/bankgiro.rb in banktools-se-0.4.0 vs lib/banktools-se/bankgiro.rb in banktools-se-0.5.0

@@ -1,11 +1,46 @@
+# http://sv.wikipedia.org/wiki/Bankgirot#Bankgironummer
+
 module BankTools
   module SE
     class Bankgiro
+      class OverlongOCR < StandardError; end
+      class BadCheckDigit < StandardError; end
 
-      # http://sv.wikipedia.org/wiki/Bankgirot#Bankgironummer
-
       attr_reader :number
+
+      # http://www.bgc.se/upload/Gemensamt/Trycksaker/Manualer/BG6070.pdf section 5.2
+      def self.number_to_ocr(number, opts = {})
+        add_length_digit = opts.fetch(:length_digit, false)
+        pad = opts.fetch(:pad, nil)
+
+        number = number.to_s
+
+        if pad
+          number += pad
+        end
+
+        if add_length_digit
+          # Adding 2: 1 length digit, 1 check digit
+          number += ((number.length + 2) % 10).to_s
+        end
+
+        number_with_ocr = number.to_s + Utils.luhn_checksum(number).to_s
+        raise OverlongOCR, "Bankgiro OCR must be 2-25 characters" if number_with_ocr.length > 25
+        number_with_ocr
+      end
+
+      def self.number_from_ocr(number, opts = {})
+        strip_length_digit = opts.fetch(:length_digit, false)
+        strip_padding = opts.fetch(:pad, false)
+
+        raise BadCheckDigit unless Utils.valid_luhn?(number)
+
+        number = number.to_s
+        number.slice!(-2) if strip_length_digit
+        number.slice!(-strip_padding.length.succ..-2) if strip_padding
+        number.chop
+      end
 
       def initialize(number)
         @number = number
       end