#!/bin/sh -eu

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

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

runscript=$(readlink -f "${1}")
# We should get runscript=/etc/sv/<service>/run, but here we check it,
# otherwise wierd things might happen.

case "${runscript}" in
(/etc/sv/*/run) # correct
	service=${runscript%/run}
	service=${service#/etc/sv/}
	;;
(*)
	usage
	exit 1
	;;
esac
readonly runscript service

export NAME=$service

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

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

if [ -r /etc/default/runit ]; then
    set -a
    . /etc/default/runit
    set +a
fi

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

readonly initscript="/etc/init.d/${service}"
readonly noreplace="/usr/share/runit/meta/${service}/noreplace"

if [ -x "${initscript}" ] ; then
	# Stopping some services (e.g display manager) is disruptive
	# and must be done only manually by user.
	if [ -f "${noreplace}" ] ; then
		if "${initscript}" status >/dev/null 2>&1 ; then
			sv down "${service}"
			exit 0
		fi
	fi
	if [ ! -h "${initscript}" ]; then
	# don't stop the script if it's a symlink: it's likely to /usr/bin/sv/
		"${initscript}" stop >/dev/null
	fi
fi

if [ -d "/etc/sv/${service}/conf" ] ; then
	exec chpst -e "/etc/sv/${service}/conf" -- /bin/sh "${runscript}"
else
	exec /bin/sh "${runscript}"
fi