#!/bin/sh

bat_dir=BAT0
[ -f "$HOME/.config/bat" ] && bat_dir="$(cat "$HOME/.config/bat")"

battery_dir="/sys/class/power_supply/$bat_dir"

[ ! -d "$battery_dir" ] && exit 1

if [ "$(cat "$battery_dir/status")" != 'Charging' ]
then
    capacity="$(cat "$battery_dir/capacity")"
    [ "$capacity" -lt 15 ] &&
        notify-send -u critical "Battery low: $capacity%"
fi

exit 0