lib/turkish_id.rb in turkish_id-0.2.0 vs lib/turkish_id.rb in turkish_id-0.2.1

@@ -1,33 +1,78 @@
 require "turkish_id/version"
 
+class String
+  def digitize
+    self.split('').map { |s| Integer(s) }
+  end
+end
+
 class TurkishId
 
   def initialize(id_number)
     begin
-      # Convert string into array of integers
-      @id_number = id_number.split('').map { |s| Integer(s) }
+      @id_number = id_number.digitize  # Convert string into array of integers
     rescue
       @id_number = ''  # Suppress error & return false (eventually)
     end
   end
 
+
+  def core
+    @id_number.take(9)
+  end
+
+
+  def self.get_checksum(id_core)
+
+    # Calculate the sums of odd and even digits
+    odds = id_core.values_at(0, 2, 4, 6, 8).reduce(:+)
+    evens = id_core.values_at(1, 3, 5, 7).reduce(:+)
+
+    # Generate checksum digits
+    d10 = ((odds * 7) - evens) % 10
+    d11 = (id_core.reduce(:+) + d10) % 10
+
+    [d10, d11]
+  end
+
+  def self.add_checksum(id_core)
+    id_core + TurkishId.get_checksum(id_core)
+  end
+
   def is_valid?
     id = @id_number  # +1 brevity point
 
     # Early elimination, bad length or first digit
     return false if id.length != 11 || id.first == 0
 
-    # Calculate the sums of odd and even digits
-    odds = id.values_at(0, 2, 4, 6, 8).reduce(:+)
-    evens = id.values_at(1, 3, 5, 7).reduce(:+)
+    # Get checksum digits
+    d10, d11 = TurkishId.get_checksum(id)
 
     # Check if the tenth digit matches the algorithm
-    return false if id[9] != ((odds * 7) - evens) % 10
+    return false if id[9] != d10
 
     # Check if the eleventh digit matches the algorithm
-    return false if id[10] != id[0..9].reduce(:+) % 10
+    return false if id[10] != d11
 
-    return true  # All conditions met
+    true  # All conditions met
+  end
+
+  def get_relatives(num, direction='up')
+
+    id = self.core.join.to_i  # Our core id as integer
+
+    tree = {'up' => 1, 'down' => -1}      # + or - based on direction
+    magic = 131 * 229 * tree[direction]   # Eliminates if statement
+
+    relatives = []
+
+    num.times do
+      id += magic      # Gives us the next relative
+      relatives << id  # Collecting ids in an array
+    end
+
+    # Traverse relatives and append checksum digits
+    relatives.map { |r| TurkishId.add_checksum(r.to_s.digitize).join }
   end
 
 end