#!/usr/bin/perl
use strict;

# signup-scripts-backend
# Copyright (C) 2006  Jeff Arnold <jbarnold@mit.edu>
# 
# This program 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.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
# 
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
# 
# See /COPYRIGHT in this repository for more information.

$ENV{PATH} = '';

my $username = $ARGV[0];

# Complain unless submitted username contains only valid characters
complain("bad username") unless($username =~ /^[\w._-]+$/);

complain("banned username") if(`@grep_path@ '$username' /afs/athena.mit.edu/contrib/scripts/admin/users.banned` != "");

my $homedir;
my $filsys = `@hesinfo_path@ $username filsys`;
# AFS /afs/athena.mit.edu/user/j/b/jbarnold w /mit/jbarnold
if($filsys =~ /^AFS\s(\/afs\/[\w\._\/-]+)\s.*\s\/mit\/$username$/) {
	$homedir = $1;
}
else {
	complain("athena user not found");
}

# Run ls to confirm user's homedir and obtain user's homedir uid
my $ls_regexp = '^\S*\s+\S*\s+(\S*)\s+(\S*)\s+\S*\s+\S*\s+\S*\s+\S*\s+(\S*).*$';
my ($uid1, $gid1, $name1) = (`@ls_path@ -dln '$homedir'` =~ $ls_regexp);

# Complain if user's homedir does not exist
complain("athena homedir not found") unless($name1 eq $homedir);

# Complain if user's uid is too low or too high
complain("bad uid") unless($uid1 > 110 and $uid1 < (1 << 31));

# Run ls to confirm user's .scripts-signup file
my ($uid2, $gid2, $name2) = (`@ls_path@ -dln '$homedir/.scripts-signup'` =~ $ls_regexp);

# Complain if user's .scripts-signup file does not exist
#complain("scripts-signup file not found") unless($name2 eq "$homedir/.scripts-signup");

# Complain if the user's username is already taken
complain("username already taken") if(getpwnam $username);

# Complain if user's uid is already taken
complain("uid already taken") if(getpwuid $uid1);

if($homedir !~ /\/afs\/athena\.mit\.edu\/user\//) {
	$gid1 = $uid1;
}

# Complain if user's gid is already taken
complain("gid already taken") if(getgrgid $gid1);

# Add user to /etc/passwd
`@sudo_path@ -u root @groupadd_path@ -g '$gid1' '$username'`;
`@sudo_path@ -u root @useradd_path@ -d '$homedir' -s '/usr/local/bin/modbash' -u '$uid1' -g '$gid1' -G users '$username'`;
# Add disk quota for user
`@sudo_path@ -u root @setquota_path@ '$username' 0 25000 0 10000 -a`;

printexit("done", 0);

sub complain {
  my ($complaint) = @_;
  printexit($complaint, 1);
}

sub printexit {
  my ($msg, $status) = @_;
  print $msg;
  exit($status);
}