#!/bin/sh
# prerm script for kasmvnc
#
# see: dh_installdeb(1)

set -e

# summary of how this script can be called:
#        * <prerm> `remove'
#        * <old-prerm> `upgrade' <new-version>
#        * <new-prerm> `failed-upgrade' <old-version>
#        * <conflictor's-prerm> `remove' `in-favour' <package> <new-version>
#        * <deconfigured's-prerm> `deconfigure' `in-favour'
#          <package-being-installed> <version> `removing'
#          <conflicting-package> <version>
# for details, see https://www.debian.org/doc/debian-policy/ or
# the debian-policy package

stop_vncserver_systemd_services_for_all_logged_in_users() {
  for session in $(list_user_sessions); do
    stop_user_services "$session"
  done
}

list_user_sessions() {
  loginctl list-sessions --no-legend | awk '{print $1}'
}

stop_user_services() {
  local session="$1"

  for service in $(list_active_services); do
    systemctl --user --machine=$(systemd_user_from_session "$session") stop "$service" || true
  done
}

systemd_user_from_session() {
  local session="$1"

  echo $(loginctl show-session "$session" -p Name --value)@
}

list_active_services() {
  systemctl --user --machine=$(systemd_user_from_session "$session") \
    list-units --type=service --state=active --plain --no-legend | \
    awk '{ print $1 }' | grep kasmvncserver
}

remove_vncserver_and_other_alternatives_from_bin() {
  bindir=/usr/bin
  mandir=/usr/share/man
  commands="kasmvncserver kasmvncpasswd kasmvncconfig Xkasmvnc kasmxproxy"

  for kasm_command in $commands; do
    generic_command=`echo "$kasm_command" | sed -e 's/kasm//'`;
    update-alternatives --remove "$generic_command" "$bindir/$kasm_command"
  done
}

case "$1" in
    remove)
      stop_vncserver_systemd_services_for_all_logged_in_users || true
      remove_vncserver_and_other_alternatives_from_bin
    ;;

    remove|upgrade|deconfigure)
      stop_vncserver_systemd_services_for_all_logged_in_users || true
    ;;

    failed-upgrade)
    ;;

    *)
        echo "prerm called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac

# dh_installdeb will replace this with shell code automatically
# generated by other debhelper scripts.

#DEBHELPER#

exit 0