package local::netmask;
require Exporter;
use strict;
use local::db;
use base "Exporter";

sub new
{
  my $invocant = shift;
  my $class = ref($invocant) || $invocant;
  # my $self  = $class->SUPER::new(@_);
  my $self=bless {}, $class;
  return $self;
}

sub check_ip_in_subnet
{
  my $self=shift;
	my ($ip,$subnet_ip,$netmask) = @_; # example 192.168.1.1, 192.168.1.0, 24 -> returns true (1)
	if ($ip =~ /\./ and $subnet_ip =~ /\./)
	{ 
	  #ipv4

		my $ip_int  = $self->v4_array_to_int(split(/\./,$ip));
		my $subnet_ip_int = $self->v4_array_to_int(split(/\./,$subnet_ip));

    my @netmask_ary;
		for my $i (0..3)
		{
      my $bits =  $netmask - $i*8;
			$bits = 8 if $bits >8;
			$bits = 0 if $bits <0;
			my $unset = 8-$bits;
      push @netmask_ary,256- (2** $unset  ) ;
		}
    my $netmask_int = $self->v4_array_to_int(@netmask_ary);
		return 1 if ( ($ip_int & $netmask_int) == ($subnet_ip_int & $netmask_int));
    return 0;
	} elsif ($ip =~ /\:/ and $subnet_ip =~ /\:/) {
	  #ipv6
		die "Only Subnet lengths of a multiple of 16 are currently supported" if $netmask % 16;
		my @ip = split(/\:/,$ip);
		my @netmask = split(/\:/,$subnet_ip);
    for my $i (1..$netmask /16)
		{
      my $ip_part = shift @ip;
			$ip_part = 0 if not $ip_part;
			my $netmask_part = shift @netmask;
			$netmask_part = 0 if not $netmask_part;
			return 0 if $netmask_part != $ip_part;
		}
		return 1;
  } else {
    return; # not matching or unknown
	}
}

sub v4_array_to_int
{
  my $self=shift;
	my @array=@_;
	return unpack( "N", pack( "C4",@array ) );
}