#!/bin/bash
# ---------------------------------------------------------------------------
# makeuser - tilde.team new user creation

# Copyright 2018, Ben Harris <ben@tilde.team>
  
# 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 3 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 at <http://www.gnu.org/licenses/> for
# more details.

# Usage: makeuser [-h|--help]

# Revision history:
# 2018-09-20 Created by new_script ver. 3.3
# ---------------------------------------------------------------------------

PROGNAME=${0##*/}
VERSION="0.1"

clean_up() { # Perform pre-exit housekeeping
  return
}

error_exit() {
  echo -e "${PROGNAME}: ${1:-"Unknown Error"}" >&2
  clean_up
  exit 1
}

graceful_exit() {
  clean_up
  exit
}

signal_exit() { # Handle trapped signals
  case $1 in
    INT)
      error_exit "Program interrupted by user" ;;
    TERM)
      echo -e "\n$PROGNAME: Program terminated" >&2
      graceful_exit ;;
    *)
      error_exit "$PROGNAME: Terminating on unknown signal" ;;
  esac
}

usage() {
  echo -e "usage: $PROGNAME [-h|--help] <username> <email> \"<pubkey>\""
}

help_message() {
  cat <<- _EOF_
  $PROGNAME ver. $VERSION
  tilde.team new user creation

  $(usage)

  Options:
  -h, --help  Display this help message and exit.

  NOTE: You must be the superuser to run this script.

_EOF_
  return
}

# Trap signals
trap "signal_exit TERM" TERM HUP
trap "signal_exit INT"  INT

# Check for root UID
if [[ $(id -u) != 0 ]]; then
  error_exit "you must be the superuser to run this script."
fi

# Parse command-line
while [[ -n $1 ]]; do
  case $1 in
    -h | --help)
      help_message; graceful_exit ;;
    -* | --*)
      usage
      error_exit "unknown option $1" ;;
    *)
      user=$1
      email=$2
      sshkey="$3"
      echo "adding new user $user with and pubkey $sshkey" 

      newpw=$(pwgen -1B 10)
      pwcrypt=$(perl -e "print crypt('${newpw}', 'sa');")

      useradd -m -p $pwcrypt -s /bin/bash $user || exit 1

      sed -e "s/newusername/$user/g" -e "s/newpassword/$newpw/" email.tmpl | sendmail $email sudoers@tilde.team

      echo "$sshkey" | sudo tee /home/$user/.ssh/authorized_keys
      toot "welcome new user ~$user!"

      break
      ;;

  esac
  shift
done


graceful_exit