#!/bin/bash

# omarchy:summary=Adjust brightness on the most likely display device.
# omarchy:args=<step>

step="${1:-+5%}"

# Start with the first possible output, then refine to the most likely given an order heuristic.
device="$(ls -1 /sys/class/backlight 2>/dev/null | head -n1)"
for candidate in amdgpu_bl* intel_backlight acpi_video*; do
  if [[ -e /sys/class/backlight/$candidate ]]; then
    device="$candidate"
    break
  fi
done

# Current brightness percentage
current=$(brightnessctl -d "$device" -m | cut -d',' -f4 | tr -d '%')

# Apply non-uniform step size: 1% steps if at or below 5%, otherwise set an
# absolute target percentage to avoid raw backlight rounding causing uneven OSD steps.
if [[ $step == "+5%" ]]; then
  if (( current < 5 )); then
    (( target = current + 1 ))
  else
    (( target = current + 5 ))
  fi

  (( target > 100 )) && target=100
  step="$target%"
elif [[ $step == "5%-" ]]; then
  if (( current <= 5 )); then
    (( target = current - 1 ))
  else
    (( target = current - 5 ))
  fi

  (( target < 1 )) && target=1
  step="$target%"
fi

# Set the actual brightness of the display device.
brightnessctl -d "$device" set "$step" >/dev/null

# Use SwayOSD to display the new brightness setting.
omarchy-swayosd-brightness "$(brightnessctl -d "$device" -m | cut -d',' -f4 | tr -d '%')"