#!/bin/sh

# Defaults
FFP_PREFIX="ffp_"
DEFAULT_CMD="/usr/bin/firefox"
MSG=""

showHelp()
{
 echo "Usage $0 [options] [profile] [cmd]"
 echo "	-l		list profiles"
 echo "	-c [profile]	create profile"
 echo "	-d [profile]	delete profile"
 echo "	-C [cmd]	specify allowed command"
 echo "	-A		allow to execute all commands"
 echo "	-p [prefix]	user name prefix, (default: ffp_)"
 echo "	-m [message]	description of profile"
 echo "	-v		verbose"
 echo ""
 echo "	[profile]	profile to be started (created if not exists)"
 echo "	[cmd]		command to be started (default: firefox)"
}

listProfiles()
{
  compgen -u | sort -u | sed -ne "/^${FFP_PREFIX}/s/^${FFP_PREFIX}//p"
}

profileExists()
{
    PROFILE="$1"
    id "${FFP_PREFIX}${PROFILE}" > /dev/null
}

deleteProfile()
{
  PROFILE="$1"
  FFP_USER="${FFP_PREFIX}${PROFILE}"
  echo -n "Delete user ${FFP_USER} [y/n]? "
  read X
  if [ "x$X" = "xy" ]
  then
    sudo sed -i /etc/sudoers.d/99-ffp -e "/(${FFP_USER})/d"
    sudo userdel -rf "${FFP_USER}"
  else
    Skipped deleting "${FFP_USER}"
  fi
}

createProfile()
{
 PROFILE="$1"
 FFP_USER="${FFP_PREFIX}${PROFILE}"
 FFP_HOME=`eval "echo ~${FFP_USER}"`

 if [ ! -d "${FFP_HOME}" ]
 then
  RPASS=`openssl passwd -1 -salt x  ${RANDOM}_${RANDOM}_${RANDOM}`
  sudo useradd --no-user-group --password "$RPASS" --create-home "$FFP_USER"

  U=`whoami`
  sudo touch /etc/sudoers.d/99-ffp
  sudo chmod 600 /etc/sudoers.d/99-ffp
  echo "$U ALL=(${FFP_USER}) NOPASSWD: ${CMD:-$DEFAULT_CMD}" | sudo tee -a /etc/sudoers.d/99-ffp
  FFP_HOME=`eval "echo ~${FFP_USER}"`
  echo "${CMD:-$DEFAULT_CMD}" | sudo tee  "${FFP_HOME}/ffp.cmd"
  echo "${MSG}" | sudo tee  "${FFP_HOME}/ffp.txt"
 fi
}

startProfile()
{
 PROFILE="$1"
 FFP_USER="${FFP_PREFIX}${PROFILE}"
 FFP_HOME=`eval "echo ~${FFP_USER}"`  # "

 xhost "+SI:localuser:$FFP_USER" > /dev/null

 test -f "${FFP_HOME}/ffp.cmd" && DEFAULT_CMD=`head -n 1 "${FFP_HOME}/ffp.cmd"`
 echo "Starting: $FFP_USER (${CMD:-$DEFAULT_CMD})"
 test -f "${FFP_HOME}/ffp.txt" && cat "${FFP_HOME}/ffp.txt"
 cd "${FFP_HOME}"
 exec screen -d -m -S "$FFP_USER" sudo -u "$FFP_USER" "${CMD:-$DEFAULT_CMD}"
}

if [ root = "$(whoami)" ]
then
  echo "*****************" >&2
  echo "Running as root !" >&2
  echo "*****************" >&2
fi

while getopts "p:Am:C:lc:d:hv" OPT
do
 case "$OPT" in
   p) FFP_PREFIX="$OPTARG"
      ;;
   A) CMD="ALL"
      ;;
   m) MSG="$OPTARG"
      ;;
   C) CMD=`which "$OPTARG"`
      ;;
   l) listProfiles
      exit $!
      ;;
   c) createProfile "$OPTARG"
      exit $!
      ;;
   d) deleteProfile "$OPTARG"
      exit $!
      ;;
   h) showHelp
      exit 0
      ;;
   v) set -x
      ;;
   *) showHelp 1>&2
      exit 1
      ;;
 esac
done

shift "$((OPTIND-1))"

if ! profileExists "$1"
then
 echo "Profile $1 doesn't exist". >&2
 exit 1
 #createProfile "$1" || exit $!
fi

if [ -n "$2" ]
then
 CMD=`which "$OPTARG"`
fi

startProfile "$1"