#!/bin/bash

# Turn off keyboard backlight before hibernate to prevent hang on power-off.
# The ASUS keyboard controller can block S4 shutdown if LEDs are active.

if [[ $1 == "pre" && $2 == "hibernate" ]]; then
  device=""
  for candidate in /sys/class/leds/*kbd_backlight*; do
    if [[ -e "$candidate" ]]; then
      device="$(basename "$candidate")"
      break
    fi
  done

  if [[ -n "$device" ]]; then
    brightnessctl -d "$device" set 0 >/dev/null 2>&1
  fi
fi