lib/egn/generator.rb in egn-0.2.0 vs lib/egn/generator.rb in egn-0.4.0

@@ -1,46 +1,49 @@
+# Generates a random valid EGN
 module Egn
   module Generator
 
-    PARITY_WEIGHTS = [2,4,8,5,10,9,7,3,6]
+    # The generated EGN will be completely random if no opitons are given.
+    # options is a hash that may have the following keys: :year, :month and :date
+    def self.generate(options={})
+      date = Util.time_rand
 
-    def self.egn
-      date = time_rand
-      year = date.year
-      mon = date.month
-      day = date.day
+      options = {
+        year:  date.year,
+        month: date.month,
+        day:   date.day
+      }.merge(options)
 
-      cent = year - (year % 100)
+      validate!(options)
+
+      century = options[:year] - (options[:year] % 100)
       sex = Random.rand(1..2)
 
-      if cent == 1800
-        mon += 20
-      elsif cent == 2000
-        mon += 40
+      if century == 1800
+        options[:month] += 20
+      elsif century == 2000
+        options[:month] += 40
       end
 
       region = Random.rand(0..999)
 
       if sex == 1 && (region %2 != 0)
         region -= 1
       elsif sex == 2 && (region % 2 == 0)
         region += 1
       end
 
-      final_year = year - cent
-      egn = final_year.to_s.rjust(2, '0') + mon.to_s.rjust(2, '0') + day.to_s.rjust(2,'0') + region.to_s.rjust(3,'0')
+      final_year = options[:year] - century
+      egn = final_year.to_s.rjust(2, '0') + options[:month].to_s.rjust(2, '0') + options[:day].to_s.rjust(2,'0') + region.to_s.rjust(3,'0')
 
-      return egn + egn_checksum(egn).to_s
+      return egn + Util.egn_checksum(egn).to_s
     end
 
-    def self.egn_checksum(egn)
-      sum = egn.split('').map(&:to_i).zip(PARITY_WEIGHTS).map { |n| n.reduce(:*) }.reduce(:+)
-
-      rest = sum % 11
-      rest < 10 ? rest : 0
+    # Check if the options contain a date that is valid and be turned into an EGN
+    def self.validate!(options)
+      raise ArgumentError, "Year out of bounds" unless (1800..2099).include?(options[:year])
+      raise ArgumentError, "Month out of bounds" unless (1..12).include?(options[:month])
+      raise ArgumentError, "Day out of bounds" unless (1..31).include?(options[:day])
     end
 
-    def self.time_rand(from = 0.0, to = Time.now)
-      Time.at(from + rand * (to.to_f - from.to_f))
-    end
   end
 end