#!/bin/sh -eu

usage () {
	cat << EOF >&2
Program /lib/runit/invoke-run must only be used as interpreter for
run scripts with full path.

Please, refer to documentation in manual page invoke-run(5). If error
persist, file bug report aganist 'runit' Debian package.
EOF
}

if [ $# = 0 ] ; then
	usage
	exit 1
fi

#sane runit service directory?
if [ ! -x "${PWD}"/run ]; then
	echo "invoke-run: error: ${PWD}/run does not exists or not executable"
	usage
	exit 1
fi

if [ -x /usr/sbin/policy-rc.d ]; then
	set +e
	 /usr/sbin/policy-rc.d "${PWD##*/}" start
	 # 0 or 104=ok // 101 = do not run
	 rc=$?
	 set -e
	 if [ "$rc" = "101" ]; then
		echo "action denied by policy-rc.d"
		sv d ${PWD##*/}
		exit 0
	 fi
fi

if [ -f "/etc/sv/${PWD##*/}/.meta/installed" ] ; then
# uninstalled, but not purged. See #929693 and commit [4c485b] in dh-runit repository.
	if ! [ -f "/usr/share/runit/meta/${PWD##*/}/installed" ] ; then
		if ! [ -d "/usr/share/runit/sv/${PWD##*/}" ]; then
			echo "invoke-run: ${PWD##*/} binary not installed"
			sv down "${PWD##*/}"
			exit 0
		fi
	fi
fi

if [ -r "${PWD}/.meta/bin" ] ; then
	if [ ! -e "$(cat ${PWD}/.meta/bin)" ]; then
		echo "invoke-run: ${PWD##*/} binary not installed"
		sv down "${PWD##*/}"
	fi
fi

if [ -r "/etc/default/${PWD##*/}" ] ; then
	# export all assigned variables, allow references to
	# undefined variables.
	set -a +u
	. "/etc/default/${PWD##*/}"
	set +a -u
fi

if [ -x "/etc/init.d/${PWD##*/}" ] ; then
	# Stopping some services (e.g display manager) is disruptive
	# and must be done only manually by user.
	if [ -f "/usr/share/runit/meta/${PWD##*/}/noreplace" ] || \
	    [ -f "${PWD}/.meta/noreplace" ] ; then
		if "/etc/init.d/${PWD##*/}" status --force-sysv >/dev/null 2>&1 ; then
			sv down "${PWD##*/}"
			exit 0
		fi
	fi
	if [ ! -h "/etc/init.d/${PWD##*/}" ] && [ ! -h /sbin/start-stop-daemon ]; then
	# don't stop the script if it's a symlink: it's likely to /usr/bin/sv/
		"/etc/init.d/${PWD##*/}" stop --force-sysv >/dev/null
	fi
fi

if [ -d "${PWD}/env" ] ; then
	exec chpst -e "${PWD}/env" -- /bin/sh "${PWD}"/run
else
	exec /bin/sh "${PWD}"/run
fi