#!/bin/sh
#
# script for setting/restoring xps13 kbd backlight state
#
# Cf http://askubuntu.com/questions/689907/dell-xps-13-9343-keyboard-backlight-on-at-boot-ubuntu-15-10
# Copyright: Copyright (c) 2015 r2rien
# License:   GPL-2
#
## Exemple of implementation:
#
# saved as executable in:
# [/usr/bin/xps13-kbd-backlight]
#
# using preferences set in $BL_CONF
# [/etc/xps13-kbd-backlight]
# (without "#~ " prefix)
#~ ## 0 : off
#~ ## 1 : min
#~ ## 2 : max
#~ default=0
#~ current=1
#
# usable at login from desktop file:
# [/etc/xdg/autostart/xps13-kbd-backlight.desktop]
# (without "#~ " prefix)
#~ [Desktop Entry]
#~ Version=1.0
#~ Type=Application
#~ Terminal=false
#~ Exec=xps13-kbd-backlight
#~ X-GNOME-Autostart-enabled=true
#~ X-GNOME-Autostart-Phase=Initialization
#~ Icon=keyboard
#~ Name=xps13-kbd-backlight
#~ Comment=set/restore xps13-kbd-backlight
#~ Categories=Utility;
#
# usable at resume|thaw linking it in /etc/pm/sleep.d
# [ln -s  /usr/bin/xps13-kbd-backlight /etc/pm/sleep.d/20_xps13-kbd-backlight]

BL_CONF=/etc/xps13-kbd-backlight
[ -f $BL_CONF ] || exit 0

BL_SYS=/sys/class/leds/dell::kbd_backlight/brightness

BL_CONF_DEFAULT=$(grep ^default $BL_CONF |awk -F = '{print $NF}')
BL_CONF_CURRENT=$(grep ^current $BL_CONF |awk -F = '{print $NF}')
BL_SYS_CURRENT=$(cat $BL_SYS)

case "${1}" in
    suspend|suspend_hybrid|hibernate)
    # save in conf new current from sys
        sudo sed -i "s/current=$BL_CONF_CURRENT/current=$BL_SYS_CURRENT/" $BL_CONF
        ;;
    resume|thaw)
    # set from current in conf
        echo $BL_CONF_CURRENT |sudo tee $BL_SYS
        ;;
    *)
    # set from default in conf
        echo $BL_CONF_DEFAULT |sudo tee $BL_SYS
        ;;
esac