#!/usr/bin/python
# Copyright 2012 Google Inc. All Rights Reserved.

"""This class defines IP address related operations."""

__author__ = 'Lin Xue (linxue@google.com)'

"""This file defines IP address related oprations.
   This includes IPv4, IPv6 check up

"""

import re
import socket


class IPADDR(object):
  """IP address class

     input: a string
     fuctions: check if the given string has something like ip address
               check if the ipv4 address is valid or not
               check if the given string is valid ipv4 address
               check if the ipv6 address is valid or not

  """

  def __init__(self, ip_address):
    self.ipaddr = ip_address

  def is_like_ipv4_address(self):
    """To check if the given string has something like
       ip address, eg. 4 numbers with 3 .
       return the ip address in the string if yes,
       if there is no, return None
    """
    ipaddr_re = re.search(r'[0-9]+(?:\.[0-9]+){3}', self.ipaddr)
    if ipaddr_re is not None:
      ipaddr = ipaddr_re.group()
      return ipaddr
    else:
      return None

  def is_valid_ipv4_address(self):
    """To check if the ipv4 address is valid or not."""
    try:
      socket.inet_aton(self.ipaddr)

    except socket.error:  # not a valid ipv4 address
      print 'Error: ' + self.ipaddr + ' is an invalid IPv4 address'
      return False

    else:
      if self.ipaddr.count('.') == 3:
        return True
      else:
        print 'Error: ' + self.ipaddr + ' is an invalid IPv4 address'
        return False

  def is_ipv4_address(self):
    """To check if the given string is valid ipv4 address."""
    return self.is_like_ipv4_address() and self.is_valid_ipv4_address()

  def is_valid_ipv6_address(self):
    """To check if the ipv6 address is valid or not."""
    try:
      socket.inet_pton(socket.AF_INET6, self.ipaddr)

    except socket.error:  # not a valid ipv6 address
      print 'Error: ' + self.ipaddr + ' is an invalid IPv6 address'
      return False

    else:
      if self.ipaddr.count(':') == 7:
        return True
      else:
        print 'Error: ' + self.ipaddr + ' is an invalid IPv6 address'
        return False

# End of IPADDR class