class UUTDNS

# File lib/uutdns.rb, line 4
def bin_to_hex(s)
  hex_value = ""
  s.scan(/(........)/).each do |x|
    value = x[0].to_i(2).to_s(16)
    value.prepend("0") if value.length == 1
    hex_value << value
  end
  hex_value.upcase
end

# File lib/uutdns.rb, line 14
def header(type = :standard)
  header = ''

  # Set id
  16.times do
    header << [*0..1].sample.to_s
  end

  # Set the QR to 0 as this is a query, not a response
  header << "0"

  # Set the header Opcode
  # 0 for standard query
  # 1 for inverse query
  case type
  when :standard
    header << "0000"
  when :inverse
    header.opcode = "0001"
  end

  # Set AA to 0
  # specifies that the responding name server is not an
  # authority for the domain name in question section.
  header << "0"

  # TrunCation - specifies that this message was truncated
  # due to length greater than that permitted on the
  # transmission channel(just for response).
  header << "0"

  # Recursion Desired
  header << "1"

  # Recursion Available(just for response)
  header << "0"

  # Z - Reserved for future use.
  header << "000"

  # RCODE - just for responses. 0 indicate that there is no error
  header << "0000"

  # QDCOUNT - the number of entries in the question section.
  header << "0" * 15 + "1"

  # ANCOUNT - the number of resource records in the answer section(for answer.
  header << "0" * 16

  # NSCOUNT - an unsigned 16 bit integer specifying the number of name
  # server resource records in the authority records section.
  header << "0" * 16

  # ARCOUNT - an unsigned 16 bit integer specifying the number of
  # resource records in the additional records section.
  header << "0" * 16

  bin_to_hex(header)
end

# File lib/uutdns.rb, line 74
def question(domain_name)
  question = ''
  question_parts = domain_name.split('.')

  # Set QNAME
  question_parts.each do |part|
    part.length
    part_bits = part.length.to_s(2)
    # partlen_hex.prepend("0") if partlen_hex.length == 1
    part_bits.prepend("0") while part_bits.length < 8
    # p part_bits
    question << part_bits
    
    part.each_byte do |b|
      byte_hex = b.to_s(2)
      byte_hex.prepend("0") while byte_hex.length < 8
      question << byte_hex
    end
  end
  
  question = bin_to_hex(question) << "00"

  # Set QTYPE
  question << "0001"

  # Set QCLASS
  question << "0001"
end