#! /usr/bin/perl -w

use strict;
use Getopt::Long;

my $progname     = "update-locale";
my $locale_file  = "/etc/default/locale";

my $help         = 0;
my $reset        = 0;
#  Kept for compatibility reasons
my $remove       = 0;
my $no_checks    = 0;

GetOptions(
	'reset'          => \$reset,
	'remove'         => \$remove,
	'locale-file=s'  => \$locale_file,
	'no-checks'      => \$no_checks,
	'h|help'         => \$help,
);

sub usage
{
	my $rc = shift;
	print STDERR "Usage: $progname [OPTIONS] [LANG=locale] [LC_NUMERIC=locale] ...
Options:
   --help              display this message and exit
   --reset             ignore variables defined in the locale file
   --locale-file=FILE  file containing locale variables
                       (Default: /etc/default/locale)
   --no-checks         do not perform sanity checks on locale variables
";
	exit $rc;
}

$help && usage(0);

#  Process command-line arguments
my %arg = ();
my $content = '';
my $mode = 0644;
if (-r $locale_file)
{
	#  Keep file mode
	$mode = (stat($locale_file))[2] & 07777;
	#  Read current values
	open(IN, "<", $locale_file)
		or die "$progname: Unable to read $locale_file: $!\n";
	while (<IN>)
	{
		$content .= $_;
		next unless m/^(\w+)=(.*)/;
		$arg{$1} = $2 unless $reset;
	}
	close(IN)
		or die "$progname: Unable to close $locale_file: $!\n";
	$content =~ s/^(\s*\w+=)/#$1/mg;
	$content .= "\n" unless $content =~ m/\n$/s;
}
else
{
	$content = "#  File generated by $progname\n";
}
for (@ARGV)
{
	if (m/(\w+)=(.*)/)
	{
		$arg{$1} = $2;
	}
	else
	{
		delete $arg{$_};
	}
}

my $env = '';
my ($key, $value);
while (($key, $value) = each %arg)
{
	$env .= " $key=$value";
	$content =~ s/^#\s*$key=.*/$key=$value/m or
		$content .= "$key=$value\n";
}

#  Sanity checks
if ($no_checks == 0)
{
	#  Check that this locale does exist
	my $charset = `LANG= LC_CTYPE= LC_NUMERIC= LC_TIME= LC_COLLATE= LC_MONETARY= LC_MESSAGES= LC_PAPER= LC_NAME= LC_ADDRESS= LC_TELEPHONE= LC_MEASUREMENT= LC_IDENTIFICATION= LC_ALL= $env locale charmap 2>&1`;
	die "*** $progname: Error: invalid locale settings: $env\n"
		if ($charset =~ m/Cannot set/);
	#  If LANGUAGE is set, its first value must be compatible with LC_MESSAGES
	if (defined $arg{LANGUAGE})
	{
		my $language = $arg{LANGUAGE};
		$language =~ s/["']//g;
		$language =~ s/[.:_].*//;
		my $msg = '';
		my $var = '';
		for (qw(LANG LC_MESSAGES LC_ALL))
		{
			if (defined $arg{$_})
			{
				$var = $_;
				$msg = $arg{$_};
			}
		}
		$msg =~ s/["']//g;
		if ($msg !~ m/^$language/ && $var ne ''
		    && $msg ne 'C' && $msg ne 'POSIX'
		    && $language ne 'C' && $language ne 'POSIX')
		{
			print "*** $progname: Warning: LANGUAGE ($arg{LANGUAGE}) is not compatible with $var ($msg). Disabling it.\n";
			$content =~ s/^(\s*LANGUAGE=)/#$1/mg;
		}
	}
}

#  Write locale file
open(OUT, ">", $locale_file)
	or die "$progname: Unable to write $locale_file: $!\n";
print OUT $content;
close(OUT)
	or die "$progname: Unable to close $locale_file: $!\n";
chmod($mode, $locale_file)
	or die "$progname: Unable to chmod $locale_file: $!\n";

1;