module Controls
  module Time
    module Elapsed
      def self.example(units, reference: nil, precision: nil)
        reference ||= Time.example
        reference = Clock.parse reference if reference.is_a? String

        units_per_second = self.units_per_second(precision: precision)
        elapsed_seconds = Rational(units, units_per_second)

        elapsed_time = reference + elapsed_seconds

        ISO8601.example elapsed_time
      end

      def self.reference(precision: nil)
        example 0, precision: precision
      end

      def self.units_per_second(precision: nil)
        precision ||= Clock::ISO8601::Defaults.precision

        10 ** precision
      end
    end
  end
end