module CompletionsConcern
  extend ActiveSupport::Concern

  def pad(n)
    if n > 9
      return n.to_s
    end
    "0" + n.to_s
  end

  def display_time(seconds)
    if seconds > 3600
      hours = seconds / 3600
      return hours.to_s + ":" + display_time(seconds % 3600)
    elsif seconds > 60
      minutes = seconds / 60
      return pad(minutes) + ":" + display_time(seconds % 60)
    end
    pad(seconds)
  end

  def extend_completions!(completions)
    current_time_from_start = 0
    @completions.each do |completion|
      completion.display_time_from_start = display_time(completion.time_seconds)
      completion.display_relative_time = display_time(completion.time_seconds - current_time_from_start)
      current_time_from_start += completion.time_seconds
    end
  end
end