kslazarev/numbers_and_words

# frozen_string_literal: true

module NumbersAndWords
  module ArrayExtensions
    module Helpers
      MICRO_CAPACITY_SHIFT = 2
      FIGURES_IN_CAPACITY = 3
      THOUSAND_CAPACITY = 1
      ONES_SHIFT = 1

      def capacity_length
        length - ONES_SHIFT
      end

      def capacity_count
        count = capacity_length / FIGURES_IN_CAPACITY
        count.zero? ? nil : count
      end

      def figures_array_in_capacity(capacity)
        self[capacity * FIGURES_IN_CAPACITY, FIGURES_IN_CAPACITY]
      end

      def number_in_capacity(capacity)
        figures_array_in_capacity(capacity).reverse.join.to_i
      end

      def number_under_capacity(capacity)
        figures_array_under_capacity(capacity).reverse.join.to_i
      end

      def opaque?(capacity)
        figures_under = figures_array_under_capacity(capacity)
        figures_under.count(0) == figures_under.length
      end

      def figures_array_under_capacity(capacity)
        self[0..(capacity * FIGURES_IN_CAPACITY) - ONES_SHIFT]
      end

      def ones
        self[0].to_i if self[0].to_i.positive?
      end

      def only_ones
        ones if !tens && !hundreds
      end

      def teens
        tens_with_ones if tens == 1
      end

      def tens
        self[1].to_i if self[1].to_i.positive?
      end

      def tens_with_ones
        [ones, tens] if ones && tens
      end

      def hundreds
        self[2].to_i if self[2].to_i.positive?
      end

      def round_hundred?
        ones.nil? && tens.nil?
      end

      def sub_capacity
        capacity_length % FIGURES_IN_CAPACITY
      end

      def fraction_capacity
        [fraction_capacity_count, fraction_sub_capacity]
      end

      def fraction_capacity_count
        capacity_count.nil? ? sub_capacity : capacity_count + MICRO_CAPACITY_SHIFT
      end

      def fraction_sub_capacity
        sub_capacity unless capacity_count.nil?
      end

      def ordinal_index
        index(&:positive?)
      end

      def ordinal_capacity
        count = ordinal_index / FIGURES_IN_CAPACITY
        count.zero? ? nil : count
      end
    end
  end
end