module Napa
  VERSION = '0.1.3'

  class Version
    class << self
      def next_major
        next_level(:major)
      end

      def next_minor
        next_level(:minor)
      end

      def next_patch
        next_level(:patch)
      end

      def next_level(level)
        fail 'Unidentified Level' unless [:major, :minor, :patch].include?(level)

        parts = Napa::VERSION.split('.').map { |p| p.to_i }

        if level == :major
          parts[0] += 1
          significant_index = 1
        end

        if level == :minor
          parts[1] += 1
          significant_index = 2
        end

        if level == :patch
          parts[2] += 1
          significant_index = 3
        end

        parts.map.with_index { |p, i| parts[i] = 0 if i >= significant_index }

        parts.join('.')
      end

    end
  end
end