#!/bin/sh

function usage {
  echo "usage: $0 up|down"
}

function main {
  if [ "$#" -ne 1 ]; then
    usage
    exit 1
  fi
  
  local method=""
  if [ "$1" == "up" ]; then
    method="org.gnome.SettingsDaemon.Power.Screen.StepUp"
  elif [ "$1" == "down" ]; then
    method="org.gnome.SettingsDaemon.Power.Screen.StepDown"
  else
    usage
    exit 1
  fi
  dbus_result=$(gdbus call --session --dest org.gnome.SettingsDaemon.Power --object-path /org/gnome/SettingsDaemon/Power --method "$method" | tr -d "(,)")
  level=$(echo "$dbus_result" | awk '{ printf "%f", $1 / 100 }')
  connector=$(echo "$dbus_result" | awk '{ print $2 }')
  gdbus call --session --dest org.gnome.Shell --object-path /org/gnome/Shell --method org.gnome.Shell.ShowOSD "{'icon': <'display-brightness-symbolic'>, 'level': <$level>, 'connector': <$connector>}"
}

main "$@"