module Riak
  module Crdt
    # The {InnerFlag} is a boolean member of a {Map}. Since flag operations are
    # extremely simple, this object simply provides internal API methods for
    # {TypedCollection} to use.
    #
    # @api private
    class InnerFlag
      def self.new(parent, value = false)
        ensure_boolean value

        return value
      end

      def self.update(value)
        ensure_boolean value

        Operation::Update.new.tap do |op|
          op.value = value
          op.type = :flag
        end
      end

      def self.delete
        Operation::Delete.new.tap do |op|
          op.type = :flag
        end
      end

      private
      def self.ensure_boolean(value)
        return if value.is_a? TrueClass
        return if value.is_a? FalseClass

        raise FlagError, t('crdt.flag.not_boolean')
      end

      class FlagError < ArgumentError
      end
    end
  end
end