#!/bin/sh
### BEGIN INIT INFO
# Provides:          brightness
# Required-Start:    $local_fs
# Required-Stop:     $local_fs
# Default-Start:     S
# Default-Stop:      0 6
# Short-Description: Save and restore brightness level between restarts.
# Description:       This script saves the brightness level between restarts.
#                    It is called from the boot, halt and reboot scripts.
### END INIT INFO

readonly SAVEFILE_PREFIX=/var/lib/initscripts/brightness

. /lib/init/vars.sh
. /lib/lsb/init-functions

do_invoke() {
	local rv=0 rc
	# ACPI (without explicit label)
	do_$1 '' \
	    /sys/class/backlight/acpi_video0/brightness \
	    /sys/class/backlight/acpi_video0/max_brightness
	rc=$?
	test $rc -lt $rv || rv=$rc
	# Intel
	do_$1 intel \
	    /sys/class/backlight/intel_backlight/brightness \
	    /sys/class/backlight/intel_backlight/max_brightness
	rc=$?
	test $rc -lt $rv || rv=$rc
	# could insert others using the same scheme here
	return $rv
}

do_status() {
	local label=$1 knob=$2 max=$3 file=$SAVEFILE_PREFIX${1:+.$1}
	test -e "$knob" || return 0

	MSG="Current${label:+ $label} brightness level is $(cat "$knob")"
	if test -f "$file"; then
		log_success_msg "${MSG}, saved value is $(cat "$file")"
		return 0
	fi
	log_failure_msg "${MSG}, there is no saved value"
	return 4
}

do_start() {
	local label=$1 knob=$2 max=$3 file=$SAVEFILE_PREFIX${1:+.$1}
	test -e "$knob" || return 0

	test x"$VERBOSE" = x"no" || \
	    log_action_begin_msg Initialising $label brightness level

	if test -f "$file"; then
		cat "$file" >"$knob"
	else
		cat "$max" >"$knob"
	fi
	local rv=$?
	test x"$VERBOSE" = x"no" || log_action_end_msg $rv
	return $rv
}

do_stop() {
	local label=$1 knob=$2 max=$3 file=$SAVEFILE_PREFIX${1:+.$1}
	test -e "$knob" || return 0

	test x"$VERBOSE" = x"no" || \
	    log_action_begin_msg Saving $label brightness level
	cat "$knob" >"$file"
	local rv=$?
	test x"$VERBOSE" = x"no" || log_action_end_msg $rv
	return $rv
}

case $1 in
(start|restart|reload|force-reload)
	do_invoke start
	;;
(stop)
	do_invoke stop
	;;
(status)
	do_invoke status
	;;
(*)
	echo >&2 "Usage: $0 {start|stop|restart|reload|force-reload|status}"
	exit 3
	;;
esac