# frozen_string_literal: true

class StringSplitter
  class Split
    # expose the +update!+ method as a refinement to StringSplitter but don't
    # expose it to blocks
    #
    # idea based on a suggestion here (as an alternative to a `friend` modifier):
    # https://bugs.ruby-lang.org/issues/12962#note-5
    module Refinements
      refine Split do
        def update!(count:, index:)
          @count = count
          @index = index
          @position = index + 1
          freeze
        end
      end
    end

    attr_reader :captures, :count, :index, :lhs, :position, :rhs, :separator
    attr_writer :rhs

    alias pos position

    def initialize(captures:, lhs:, rhs:, separator:)
      @captures = captures
      @lhs = lhs
      @rhs = rhs
      @separator = separator
    end

    # 0-based index relative to the end of the array, e.g. for 5 items:
    #
    #  index | rindex
    #  ------|-------
    #    0   |   4
    #    1   |   3
    #    2   |   2
    #    3   |   1
    #    4   |   0
    def rindex
      @count - @position
    end

    # 1-based position relative to the end of the array, e.g. for 5 items:
    #
    #   position | rposition
    #  ----------|----------
    #      1     |    5
    #      2     |    4
    #      3     |    3
    #      4     |    2
    #      5     |    1
    def rposition
      @count + 1 - @position
    end

    alias rpos rposition
  end
end