#!/usr/bin/perl -w

################################################################################
# Copyright (c) 2011 University of Utah Student Computing Labs.
# All Rights Reserved.
#
# Permission to use, copy, modify, and distribute this software and
# its documentation for any purpose and without fee is hereby granted,
# provided that the above copyright notice appears in all copies and
# that both that copyright notice and this permission notice appear
# in supporting documentation, and that the name of The University
# of Utah not be used in advertising or publicity pertaining to
# distribution of the software without specific, written prior
# permission. This software is supplied as is without expressed or
# implied warranties of any kind.
################################################################################

use Foundation;
use lib "/usr/local/lib/";
require "perlplist.pl";

use Getopt::Std;

#####
# Get options
#
getopts( "zi:r:s:", \%options );

usage() if ! defined $ARGV[0];

my $set_ip = $ARGV[0];
my $networkPrefs = defined $ARGV[1] ? $ARGV[1] : "/Library/Preferences/SystemConfiguration/preferences.plist";

my $router;
my $debug;
my $subnetmask;
my $interface_name;

if ( defined $options{'z'} ) {
  $debug = 1;
} else {
  $debug = 0;
}

if ( defined $options{'i'} ) {
  $interface_name = $options{'i'};
} else {
  $interface_name = 'Ethernet';
}

if ( defined $options{'r'} ) {
  $router = $options{'r'};
} else {
  $router = '';
}

if ( defined $options{'s'} ) {
  $subnetmask = $options{'s'};
} else {
  $subnetmask = '';
}

print "Modifying $networkPrefs\n";

#####
# Load prefs
#
my $dict;
if ( -e $networkPrefs ) {
  $dict = loadDefaults( $networkPrefs );
} else {
  die "The file: $networkPrefs not found";
}

my $currentSet = perlValue(getPlistObject($dict, "CurrentSet"));
$currentSet =~ s/\/Sets\///;
print "currentSet $currentSet\n" if $debug;

@serviceOrder = perlArrayFromNSArray(getPlistObject($dict, "Sets", $currentSet, "Network", "Global", "IPv4", "ServiceOrder"));

my $ip;
my $made_change = 0;

########
# Find the user defined name and change its IP
#
foreach $ii ( @serviceOrder ) {
	my $serviceKey = perlValue($ii);
	print "serviceKey $serviceKey\n" if $debug;
	my $userDefinedName = perlValue(getPlistObject($dict, "NetworkServices", $serviceKey, "UserDefinedName"));
	print "userDefinedName $userDefinedName\n" if $debug;

	if ( $userDefinedName eq $interface_name ) {

		if ( $set_ip eq lc( "dhcp" ) ) {

			setPlistObject($dict, "NetworkServices", $serviceKey, "IPv4", "ConfigMethod", "DHCP");
			$made_change = 1;

		} else {

			my $configMethod = perlValue(getPlistObject($dict, "NetworkServices", $serviceKey, "IPv4", "ConfigMethod"));
			if ( $configMethod eq "Manual" ) {
			}

			$made_change = 1;

			setPlistObject($dict, "NetworkServices", $serviceKey, "IPv4", "ConfigMethod", "Manual");
			setPlistObject($dict, "NetworkServices", $serviceKey, "IPv4", "Addresses", 0, $set_ip);
			if ( $router ne '' ) {
				setPlistObject($dict, "NetworkServices", $serviceKey, "IPv4", "Router", $router);
			}
			if ( $subnetmask ne '' ) {
				setPlistObject($dict, "NetworkServices", $serviceKey, "IPv4", "SubnetMasks", 0, $subnetmask);
			}

		}

		last;
	}
}

if ( ! $made_change ) {
	print "Cound not find $interface_name. No changes made.\n";
}

#####
# Save file
#
saveDefaults( $dict, $networkPrefs );

sub usage {
	print <<EOF;
Usage $0  [-i (Ethernet|Airport|FireWire)] [-r <router>] [-s <subnetmask>] (12.34.56.78|dhcp) [path to preferences.plist file]
If no path is given, it will use /Library/Preferences/SystemConfiguration/preferences.plist.
EOF
	exit;
}

exit 0;