module PrettyNumber

# File lib/pretty_number.rb, line 31
def self.decrypt encryption_code
  begin
    radix = encrypt_array.count
    secret_hash = Hash[encrypt_array.map.with_index.to_a]
    convert_array = encryption_code.each_char.map{|i| secret_hash[i]}
    number = 0
    convert_array.reverse.each_with_index do |i, index|
      number += i*radix**index
    end
    return number
  rescue => e
    return nil
  end
end

# File lib/pretty_number.rb, line 15
def self.encrypt number
  begin
    radix = encrypt_array.count
    convert_array =[]
    while number != 0 do
      merchant, arithmetical_compliment = number.divmod radix
      convert_array << arithmetical_compliment
      number = merchant
    end
    convert_array = [0] if convert_array.empty?
    secret_str = convert_array.reverse.map{|i| encrypt_array.at(i)}.join
  rescue => e
    return nil
  end
end

# File lib/pretty_number.rb, line 11
def self.encrypt_array
  encrypt_array = @encrypt_array || DefaultEncryptArray
end

# File lib/pretty_number.rb, line 6
def self.init encrypt_array
  @encrypt_array = encrypt_array.is_a?(Array) ? encrypt_array : nil
  return self
end