module ActiveData
  module Model
    module Attributes
      class ReferenceOne < Base
        def write value
          pollute do
            previous = type_casted_value
            result = write_value value
            if (!value.nil? && type_casted_value.nil?) || type_casted_value != previous
              association.reset
            end
            result
          end
        end

        def read
          if association.target
            association.identify
          else
            type_casted_value
          end
        end

        def read_before_type_cast
          @value_cache
        end

      private

        def type_casted_value
          variable_cache(:value) do
            typecast(read_before_type_cast)
          end
        end

        def association
          @association ||= owner.association(reflection.association)
        end
      end
    end
  end
end