#!/bin/sh

calc() {
	awk "BEGIN {print int($*)}"
}

msgTag="brightness" # Arbitrary but unique message tag
oldbrightness="$(cat /sys/class/backlight/*/brightness)"
newbrightness="$(calc "$oldbrightness + $1 * 2.55")"
percentage=$(calc "$newbrightness * .39215686274509803921")
highlight="#7aa2f7"

if [ "$percentage" -gt "100" ]; then
	icon="gpm-brightness-lcd"
    percentage=100
    newbrightness=255
elif [ "$percentage" -gt "50" ]; then
	icon="gpm-brightness-lcd"
elif [ "$percentage" -gt "0" ]; then
	icon="gpm-brightness-lcd-disabled"
else
	icon="gpm-brightness-lcd-disabled"
    percentage=0
    newbrightness=0
fi

echo $newbrightness | tee /sys/class/backlight/*/brightness

notify-send -a "changeBrightness" -i "$icon" -u low "Brightness: ${percentage}%" \
	-h string:x-dunst-stack-tag:$msgTag \
	-h int:value:$percentage \
	-h string:hlcolor:$highlight