#!/bin/sh

# default
step=+5
vol_max=125

cur_vol_left=$(pactl get-sink-volume @DEFAULT_SINK@ | grep -o '[0-9]\+%' | sed -n '1p'| sed 's/%//g')
cur_vol_right=$(pactl get-sink-volume @DEFAULT_SINK@ | grep -o '[0-9]\+%' | sed -n '2p' | sed 's/%//g')
cur_vol_average=$(((cur_vol_left+cur_vol_right)/2))

while getopts s:m: flag
do
    case "${flag}" in
        s) step=${OPTARG};;
        m) vol_max=${OPTARG};;
        *) echo "Usage: -s <+value/-value> -m <max volume>";;
    esac
done

new_vol=$((cur_vol_average + step))

if [ "$new_vol" -le "0" ]; then
    pactl set-sink-volume @DEFAULT_SINK@ 0%
elif [ "$new_vol" -ge "$vol_max" ] ; then
    pactl set-sink-volume @DEFAULT_SINK@ "$vol_max"%
else
    pactl set-sink-volume @DEFAULT_SINK@ "$step"%
fi