#!/usr/bin/env python3

import os, sys, string, subprocess

def main():
    cmd = "xrandr --verbose | grep {} -A 5 | grep Brightness | cut -f 2 -d ' '".format(display())
    brightness = float(subprocess.getoutput(cmd))

    if sys.argv[1] == "+" and brightness < 1:
        brightness += .25
    elif sys.argv[1] == "-" and brightness > 0:
        brightness -= .25
    os.system("xrandr --output {} --brightness {}".format(display(), brightness))

def display():
    cmd = "xdotool getmouselocation --shell | head -n -3 | sed 's/[^0-9]*//g'"
    cmd = subprocess.getoutput(cmd)

    if int(cmd) < 2560:
        return "DP-1"
    return "DP-2"

if len(sys.argv) <= 1:
    print("Usage: {} [+|-]".format(sys.argv[0]))
    sys.exit(1)
else:
    main()