#!/bin/bash
# Configure Stormux
# A script to configure the system for new users.
#
# Copyright 2020, Storm Dragon, <storm_dragon@linux-a11y.org>
#
# This 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 3, or (at your option) any later
# version.
#
# This software 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 package; see the file COPYING.  If not, write to the Free
# Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.
#
#--code--


    # The user can not be logged in when the name change occurs.
    # Write a file to /etc/cron.d/chuser
    # The file will run at boot, change the username, and delete itself.

    if [[ $# -ne 1 ]]; then
	        msgbox "Missing required argument, username."
	        exit 1
    fi

    if [[ "$(whoami)" == "root" ]]; then
	        msgbox "Please run this script as the user you would like to rename, not as root."
	        exit 1
    fi

    oldUser="$USER"

    groups="$(groups "$oldUser")"
    groups="${groups// /,}"

    newUser="$1"
    if ! [[ "$newUser" =~ ^[a-z][-a-z0-9]*$ ]]; then
	        msgbox "Username $newUser failed validation. It cannot contain spaces or some punctuation."
	        exit 1
    fi

# Heredocument left-aligned
cat << EOF | sudo tee /etc/cron.d/0chuser &> /dev/null
SHELL=/bin/bash
PATH=/sbin:/bin:/usr/sbin:/usr/bin
@reboot root usermod -a -G $groups -m -d /home/$newUser -l $newUser $oldUser && sed -i -e "s#NODM_USER=.*#NODM_USER='$newUser'#" -e "s#NODM_XSESSION=.*#NODM_XSESSION='/home/$newUser/.xinitrc'#" /etc/nodm.conf; rm -f /etc/cron.d/0chuser;reboot

EOF
# Heredocument end.

    # Files in cron.d must be 644 to work.
    sudo chmod 644 /etc/cron.d/0chuser