class ProgressBar
  module Components
    class EstimatedTimer
      include Timer
      include Progressable

      VALID_OOB_TIME_FORMATS = [:unknown, :friendly, nil]

      def initialize(options = {})
        @out_of_bounds_time_format = nil
        @starting_at               = nil
        @stopped_at                = nil

        super
      end

      def start(options = {})
        as(Timer).start
        as(Progressable).start(options)
      end

      def reset
        as(Timer).reset
        as(Progressable).reset
      end

      def out_of_bounds_time_format=(format)
        raise "Invalid Out Of Bounds time format.  Valid formats are #{VALID_OOB_TIME_FORMATS.inspect}" unless VALID_OOB_TIME_FORMATS.include? format

        @out_of_bounds_time_format = format
      end

      def to_s
        " ETA: #{estimated_time}"
      end

    private
      def estimated_time
        return '??:??:??' if running_average.zero? || total.nil?

        hours, minutes, seconds = *divide_seconds(estimated_seconds_remaining)

        if hours > 99 && @out_of_bounds_time_format
          out_of_bounds_time
        else
          sprintf TIME_FORMAT, hours, minutes, seconds
        end
      end

      def estimated_seconds_remaining
        (elapsed_seconds * (self.total / self.running_average  - 1)).round
      end

      def out_of_bounds_time
        case @out_of_bounds_time_format
        when :unknown
          '??:??:??'
        when :friendly
          '> 4 Days'
        end
      end

      def as(ancestor, &blk)
        @__as ||= {}
        unless r = @__as[ancestor]
          r = (@__as[ancestor] = As.new(self, ancestor))
        end
        r.instance_eval(&blk) if block_given?
        r
      end

      class As
        private(*instance_methods.select { |m| m !~ /(^__|^\W|^binding$)/ })

        def initialize(subject, ancestor)
          @subject = subject
          @ancestor = ancestor
        end

        def start(*args, &blk)
          @ancestor.instance_method(:start).bind(@subject).call(*args,&blk)
        end

        def method_missing(sym, *args, &blk)
          @ancestor.instance_method(sym).bind(@subject).call(*args,&blk)
        end
      end
    end
  end
end