Crypto Square

crypto_square.rb

class Crypto
  def initialize(text)
    @text = text
  end

  def normalize_plaintext
     @text.gsub(/\W/,'').downcase
  end

  def size
    Math.sqrt(normalize_plaintext.length).ceil
  end

  def plaintext_segments
    segments = []
    normalized = normalize_plaintext
    until normalized.empty?
      segments << normalized.slice!(0...size)
    end
    segments
  end

  def ciphertext
    segments = plaintext_segments
    ciphered = ''
    segments.length.times do
      segments.each do |seg|
        ciphered << seg.slice!(0)
        if seg.empty?
          seg << '*'
        end
      end 
    end
    ciphered.delete('*')
  end

  def normalize_ciphertext
    result = []
    l = plaintext_segments.map(&:length).max
    transposed = plaintext_segments.map(&:chars).map{|e| e.values_at(0...l)}.transpose
    transposed.each { |array| result << array.compact.join}
    result.join(' ')
  end
end