encryptor

class Encryptor
  def cipher(rotation)
    characters = (' '..'z').to_a
    rotated_characters = characters.rotate(rotation)
    Hash[characters.zip(rotated_characters)]
  end

  def encrypt_letter(letter,rotation)
    lowercase_letter = letter.downcase
    cipher_for_rotation = cipher(rotation)
    cipher_for_rotation[lowercase_letter]
  end

  def encrypt(string, rotation)
    letters = string.split("")

    results = []
    letters.each do |letter|
      encrypted_letter = encrypt_letter(letter, rotation)
      results.push(encrypted_letter)
    end

    results.join
  end
end