#! /bin/sh
### BEGIN INIT INFO
# Provides:          gapd
# Required-Start:    $remote_fs $syslog
# Required-Stop:     $remote_fs $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: GAP SCSCP server
# Description:       SCSCP server for the GAP Computer Algebraic System
### END INIT INFO

#
# Author: Jerome Benoit <calculus@rezozer.net>
#

# Do NOT "set -e"

# PATH should only include /usr/* if it runs after the mountnfs.sh script
PATH=/sbin:/usr/sbin:/bin:/usr/bin
DESC="GAP SCSCP server"
NAME=gapd
REALNAME=gap
DAEMON=/usr/sbin/gapd
DAEMONUSER=_gapd
DAEMONARGS="-t log"
RUNDIR=/run/gapd
LOCKFILE=$RUNDIR/gapd.lock
PIDFILE=$RUNDIR/gapd.pid
WKSFILE=$RUNDIR/gapd.wks
LOGDIR=/var/log/gapd
LOGFILE=$LOGDIR/gapd.log
SCRIPTNAME=/etc/init.d/$NAME

# Exit if the package is not installed
[ -x "$DAEMON" ] || exit 0

# Exit if the DAEMONUSER does not exist
if ! getent passwd | grep -q "^$DAEMONUSER:"; then exit 0 ; fi

# Cleanup enviroment
unset TMPDIR TMP TEMPDIR TEMP LANG LANGUAGE

# Read configuration variable file if it is present
GAPD_OPTIONS=""
[ -r /etc/default/$NAME ] && . /etc/default/$NAME
DAEMONARGS="$DAEMONARGS $GAPD_OPTIONS"

# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh

# Define LSB log_* functions.
. /lib/lsb/init-functions

# START_GAPD meant to be set up in /etc/default/$NAME
case "$START_GAPD" in
  NO|no)
    START_GAPD=NO
  ;;
  *)
    START_GAPD=YES
  ;;
esac

daemon_mkdir()
{
	local dmod=$1
	local ddir=$2
	mkdir --parents $ddir
	chmod $dmod $ddir
	chown $DAEMONUSER $ddir
	chgrp $DAEMONUSER $ddir
}

daemon_touch_log()
{
	touch $LOGFILE
	chmod 0640 $LOGFILE
	chown $DAEMONUSER $LOGFILE
	chgrp $DAEMONUSER $LOGFILE
}

daemon_tmpdir()
{
	if [ -z "$TMPDIR" ]; then
		if [ -r /etc/security/tmpdir.conf ]; then
			unset tmpdir
			. /etc/security/tmpdir.conf
			TMPDIR=${tmpdir:-/tmp}/$(id -u $DAEMONUSER)
		else
			TMPDIR=/tmp/$DAEMONUSER
		fi
	fi
	if [ ! -d $TMPDIR ]; then
			mkdir --parents $TMPDIR
			chmod 0700 $TMPDIR
			chown $DAEMONUSER $TMPDIR
	fi
	export TMPDIR
}

do_start()
{
	# Return
	#   0 if daemon has been started
	#   1 if daemon was already running
	#   2 if daemon could not be started
	#   4 if daemon is disabled

	[ "$START_GAPD" = "NO"  ] && return 4

	local counter=60
	local WORKSPACE

	daemon_mkdir 0700 $RUNDIR
	daemon_mkdir 0750 $LOGDIR

	daemon_touch_log

	start-stop-daemon --start --quiet --chuid $DAEMONUSER --pidfile $PIDFILE --startas $DAEMON --test > /dev/null 2>&1 || return 1

	daemon_tmpdir

	WORKSPACE=$(mktemp --quiet --tmpdir --directory gapd-XXXXXXXXXXX) > /dev/null 2>&1 || return 2
	chown $DAEMONUSER $WORKSPACE
	chgrp $DAEMONUSER $WORKSPACE
	export TMPDIR=$WORKSPACE
	echo $WORKSPACE > $WKSFILE

	start-stop-daemon --start --quiet --chuid $DAEMONUSER --chdir $WORKSPACE --pidfile $PIDFILE --startas $DAEMON -- $DAEMONARGS > /dev/null 2>&1 || return 2

	while [ -f ${LOCKFILE} -a 0 -lt $counter ]; do
		sleep 0.5
		counter=$((counter - 1))
	done

	return 0
}

do_stop()
{
	# Return
	#   0 if daemon has been stopped
	#   1 if daemon was already stopped
	#   2 if daemon could not be stopped
	#   other if a failure occurred

	local WORKSPACE

	start-stop-daemon --stop --quiet --user $DAEMONUSER --retry=TERM/30/KILL/5 --pidfile $PIDFILE --name $REALNAME
	RETVAL="$?"
	[ "$RETVAL" = 2 ] && return 2

	sleep 0.25

	start-stop-daemon --stop --quiet --user $DAEMONUSER --oknodo --retry=0/30/KILL/5 --exec $DAEMON
	[ "$?" = 2 ] && return 2

	if [ -f $WKSFILE ]; then
		WORKSPACE=$(cat $WKSFILE)
		if [ -d $WORKSPACE ]; then
			rm -rf $WORKSPACE
		fi
		rm -f $WKSFILE
	fi
	rm -f $PIDFILE

	return "$RETVAL"
}

case "$1" in
  start)
	[ "$VERBOSE" != no ] && log_daemon_msg "Starting $DESC" "$NAME"
	do_start
	case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
		4) [ "$VERBOSE" != no ] && { log_progress_msg "disabled, see /etc/default/gapd" ; log_end_msg 255 ; } ;;
	esac
	;;
  stop)
	[ "$VERBOSE" != no ] && log_daemon_msg "Stopping $DESC" "$NAME"
	do_stop
	case "$?" in
		0|1) [ "$VERBOSE" != no ] && log_end_msg 0 ;;
		2) [ "$VERBOSE" != no ] && log_end_msg 1 ;;
	esac
	;;
  status)
	status_of_proc -p $PIDFILE "$DAEMON" "$NAME" && exit 0 || exit $?
	;;
  restart|force-reload)
	log_daemon_msg "Restarting $DESC" "$NAME"
	do_stop
	case "$?" in
	  0|1)
		do_start
		case "$?" in
			0) log_end_msg 0 ;;
			1) log_end_msg 1 ;; # Old process is still running
			*) log_end_msg 1 ;; # Failed to start
		esac
		;;
	  *)
		# Failed to stop
		log_end_msg 1
		;;
	esac
	;;
  *)
	echo "Usage: $SCRIPTNAME {start|stop|status|restart|force-reload}" >&2
	exit 3
	;;
esac

:
