#!/usr/bin/perl -w
#
# update-nsswitch
#
# Copyright (C) 2004 Fabio Tranchitella <kobold@kobold.it>
# Copyright (C) 2004 Giuseppe Sacco <eppesuig@debian.org>
#
# update-nsswitch is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published
# by the Free Software Foundation; either version 2 of the License,
# or (at your option) any later version.
#

use strict;
use Getopt::Long;
use File::Basename qw(basename);
use File::Temp qw(tempfile);

my $CONF_FILE = "./nsswitch.conf";
my $VERSION = '0.01';

sub main {
	my ($m_add, $m_remove, $m_version, $m_help, $before, $after, $database, $actionitem);
    $m_add = $m_remove = 0;
    $after = $before = $actionitem = "";

	GetOptions(
		'add|a'       => \$m_add,
		'remove|r'	  => \$m_remove,
		'database=s'  => \$database,
		'before=s'	  => \$before,
		'after=s'	  => \$after,
		'actionitem=s'=> \$actionitem,
		'version|v'	  => \$m_version,
		'help|h'      => \$m_help
	);

	version() if ($m_version);
	usage() if ($m_help or ($m_add + $m_remove) != 1 or not $database or not @ARGV or
	            ($after ne "" and $before ne ""));

    my $source = shift @ARGV if @ARGV;

	if ($m_add) {
       return add($source, $database, $after, $before, $actionitem);
	} else {
       return remove($source, $database);
	}

}
sub add {
	my ($source, $database, $after, $before, $actionitem) = @_;
    my $output = "";
	my $done = 1;

	open(IN, $CONF_FILE) or die "Couldn't open $CONF_FILE $!\n";
	while (<IN>) {
	    if ($_ =~ /^#/ or $_ =~ /^[\s\t]+/) {
			$output .= $_;
		} elsif ($_ =~ /(\S+):[\s\t]+([\S ]+)/) {
			my ($db, $s) = ($1, $2);
			if ($database =~ /$db/ and $_ !~ /\s$source/) {

				if ($actionitem ne "") {
                	$source .= " [$actionitem]";
					$actionitem = "";
				}

				if ($after eq "" and $before eq "") {
					$after = "THELAST";
				}

			    if ($after ne "") {
					if ($_ =~ /$after/) {
						$_ =~ s/$after/$after $source/ig;
					} elsif ($after eq "THELAST") {
					    chop($_);
						$_ = $_ . " $source" . "\n";
					} else {
						$done = 0;
						last;
					}
				}

			    if ($before ne "") {
					if ($_ =~ /$before/) {
						$_ =~ s/$before/$source $before/ig;
					} else {
						$done = 0;
						last;
					}
				}
			}
			$output .= $_;
		}
	}
	close IN;

	if ($done > 0) {
		my ($tmp, $filetmp) = tempfile('nsswitch.conf.tmpXXXX') or die ("Couldn't open a temporary file: $!\n");
		print $tmp $output;
		close($tmp);
		rename("$filetmp", $CONF_FILE) or die "Couldn't rename ".$filetmp.": $!\n";
		return 0;
	} else {
		return 1;
	}
}

sub remove {
	my ($source, $database) = @_;
    my $output = "";
	my $done = 0;

	open(IN, $CONF_FILE) or die "Couldn't open $CONF_FILE $!\n";
	while (<IN>) {
	    if ($_ =~ /^#/ or $_ =~ /^[\s\t]+/) {
			$output .= $_;
		} elsif ($_ =~ /(\S+):[\s\t]+([\S ]+)/) {
			my ($db, $s) = ($1, $2);
			if ($database =~ /$db/ and $_ =~ /\s$source/) {
				$_ =~ s/\s?$source(\s\[[^\]]+\])?//ig;
				if ($_ !~ /^\S+:[\s\t]+(\S)+/) {
					$done = 0;
					last;
				}
				$done++;
			}
			$output .= $_;
		}
	}
	close IN;

	if ($done > 0) {
		my ($tmp, $filetmp) = tempfile('nsswitch.conf.tmpXXXX') or die ("Couldn't open a temporary file: $!\n");
		print $tmp $output;
		close($tmp);
		rename("$filetmp", $CONF_FILE) or die "Couldn't rename ".$filetmp.": $!\n";
		return 0;
	}
	return 1;
}

sub usage {
	print <<EOT;
Usage: update-nsswitch [OPTIONS] MODE SOURCE

Options:
  --version             output version information and exit
  --help                display this help and exit
  --database=DB1,DB2..  modify only DB1,DB2... databases
  --before=SOURCE       add the new source before SOURCE
  --after=SOURCE        add the new source after SOURCE
  --actionitem=ACTION   specify the status action clauses (without []) 

Modes:
  --add SOURCE          add a new source
  --remove SOURCE       remove an existing source 

EOT
	exit 0;
}

sub version {
	print <<EOT;
update-pam $VERSION
EOT
	exit 0;
}

######################################
## MAIN CALL, PLEASE DON'T CHANGE IT #
######################################

exit main();