#!/bin/bash
set -e

# Adjust keyboard backlight brightness using available steps.
# Usage: nomarchy-brightness-keyboard <up|down|cycle>

direction="${1:-up}"

# Find keyboard backlight device (look for *kbd_backlight* pattern in leds class).
device=""
for candidate in /sys/class/leds/*kbd_backlight*; do
  if [[ -e $candidate ]]; then
    device="$(basename "$candidate")"
    break
  fi
done

if [[ -z $device ]]; then
  echo "No keyboard backlight device found" >&2
  exit 1
fi

# Get current and max brightness to determine step size.
max_brightness="$(brightnessctl -d "$device" max)"
current_brightness="$(brightnessctl -d "$device" get)"

# Calculate step as one unit (keyboards typically have discrete levels like 0-3).
if [[ $direction == "cycle" ]]; then
  new_brightness=$(( (current_brightness + 1) % (max_brightness + 1) ))
elif [[ $direction == "up" ]]; then
  new_brightness=$((current_brightness + 1))
  (( new_brightness > max_brightness )) && new_brightness=$max_brightness
else
  new_brightness=$((current_brightness - 1))
  (( new_brightness < 0 )) && new_brightness=0
fi

# Set the new brightness.
brightnessctl -d "$device" set "$new_brightness" >/dev/null

# Use SwayOSD to display the new brightness setting.
percent=$((new_brightness * 100 / max_brightness))
nomarchy-swayosd-kbd-brightness "$percent"
