alebian/crf

require 'concurrent/atomic/semaphore'

module Crf
  class RepetitionsList
    attr_reader :uniques, :repetitions, :total_repetitions

    def initialize
      @uniques = {}
      @repetitions = {}
      @semaphore = Concurrent::Semaphore.new(1)
      @total_repetitions = 0
    end

    ##
    # Adds an element to one of each hashes. If the value is repeated, then it erases it from
    # uniques and adds it in the repetitions hash along with the duplicate.
    #
    # @param key result of the function that identifies the file
    # @param value [String] path of the file
    #
    def add(key, value)
      @semaphore.acquire
      if repetitions.key?(key)
        repetitions[key] << value
        @total_repetitions += 1
      elsif uniques.key?(key)
        repetition_found(key, value)
      else
        uniques[key] = value
      end
      @semaphore.release
    end

    private

    def repetition_found(key, value)
      repetitions[key] = [value]
      repetitions[key] << uniques[key]
      @total_repetitions += 2
      uniques.delete(key)
    end
  end
end