IpCalculator

IpCalculator.rb

class Ip < Array
  def initialize(arg)
    case arg
    when Array # array with octets
      concat(arg)
    when /(\d{1,3}\.){3}\d{1,3}/ # string with decimal address - splitted by dots
      concat(arg.split('.')).map!(&:to_i)
    when /\d{1,32}/ # string with binary address - not splitted by dots
      concat(arg.scan(/\d{1,8}/).map { |oct| oct.to_i(2) })
    else
      raise 'Passed argument is not valid!'
    end
  end

  def to_binary
    map.each.inject('') do |octets, part|
      binary = part.to_s(2)
      octets += binary.insert(0, '0' * (8 - binary.size)) # complemented with '0' at 0 position if octet has not 8 digits
    end
  end

  def to_s
    join('.')
  end
end

class Mask < Ip
  def initialize(arg)
    if arg.kind_of?(Integer)
      binary_mask = '1' * arg + '0' * (32 - arg) # create binary address
      super(binary_mask)
    else
      super(arg)
    end
    raise 'Mask is not valid!' if to_binary[/1{1,32}0{1,32}/].size < 32
  end
end

class IpCalculator
  attr_reader :ip, :mask

  def initialize(ip, mask)
    @ip = Ip.new(ip)
    @mask = Mask.new(mask)
  end

  def host
    host = []
    ip.each_with_index do |el, i|
      host[i] = el & mask[i]
    end
    Ip.new(host)
  end

  def broadcast
    binary_host = host.to_binary
    number_of_zeros = mask.to_binary.reverse.scan(/./).index('1')
    binary_host[-number_of_zeros..-1] = '1' * number_of_zeros # change from 0 to 1
    Ip.new(binary_host)
  end
end

calc = IpCalculator.new('126.0.0.1', '255.255.248.0')
puts "ip:   #{calc.ip}"
puts "mask: #{calc.mask}"
puts 'calculating..'
puts "host:      #{calc.host}"
puts "broadcast: #{calc.broadcast}"

puts '---'
ip = Ip.new('126.0.0.1')
mask = Mask.new('255.255.248.0')
calc = IpCalculator.new(ip, mask)
puts "ip:   #{calc.ip}"
puts "mask: #{calc.mask}"
puts 'calculating..'
puts "host:      #{calc.host}"
puts "broadcast: #{calc.broadcast}"

puts '---'
calc = IpCalculator.new(ip, 21)
puts "ip:   #{calc.ip}"
puts "mask: #{calc.mask}"
puts 'calculating..'
puts "host:      #{calc.host}"
puts "broadcast: #{calc.broadcast}"

puts '---'
puts 'Mask validator'
begin
  Mask.new '123.123.123.0'
rescue RuntimeError
  puts 'Huh! your mask is not valid ;-('
end