#!/bin/sh

BR_DIR="/sys/class/backlight/intel_backlight/"


test -d "$BR_DIR" || exit 0

MIN=0
MAX=$(cat "$BR_DIR/max_brightness")
VAL=$(cat "$BR_DIR/brightness")

if [ "$1" = down ]; then
    VAL=$((VAL-4096))
else
    VAL=$((VAL+4096))
fi

if [ "$VAL" -lt $MIN ]; then
    VAL=$MIN
elif [ "$VAL" -gt $MAX ]; then
    VAL=$MAX
fi

PERCENT=`echo "$VAL / $MAX" | bc -l`

export XAUTHORITY=$HOME/.Xauthority  # CHANGE "ivo" TO YOUR USER
export DISPLAY=:0

echo "xrandr --output eDP-1 --brightness $PERCENT" > /tmp/oled-brightness.log
xrandr --output eDP-1 --brightness $PERCENT

echo $VAL | sudo tee "$BR_DIR/brightness"
