add: country subdivision string type

lib/kdl/types/country.rb

@@ -1,4 +1,5 @@
 require 'kdl/types/country/iso3166_countries'
+require 'kdl/types/country/iso3166_subdivisions'
 
 module KDL
   module Types
@@ -21,7 +22,6 @@ def self.call(value, type = 'country-3')
 
         new(country, type: type)
       end
-
     end
     Country3 = Country
     MAPPING['country-3'] = Country3
@@ -42,6 +42,28 @@ def self.call(value, type = 'country-2')
     end
     MAPPING['country-2'] = Country2
 
-    # TODO: country-subdivision??
+    class CountrySubdivision < Value
+      attr_reader :country, :name
+
+      def initialize(value, type: 'country-subdivision', country:, name:, **kwargs)
+        super(value, type: type, **kwargs)
+        @country = country
+        @name = name
+      end
+
+      def self.call(value, type = 'country-subdivision')
+        return nil unless value.is_a? ::KDL::Value::String
+
+        country2 = value.value.split('-').first
+        country = Country::COUNTRIES2[country2.upcase]
+        raise ArgumentError, 'invalid country' unless country
+
+        subdivision = COUNTRY_SUBDIVISIONS.dig(country2.upcase, value.value)
+        raise ArgumentError, 'invalid country subdivision' unless subdivision
+
+        new(value.value, type: type, name: subdivision, country: country)
+      end
+    end
+    MAPPING['country-subdivision'] = CountrySubdivision
   end
 end