#!/bin/bash
sink=$(pacmd list-sinks | grep "* index" | grep -oE '[0-9]*')
cmd=""
app="pavucontrol"

if [ -z "$sink" ]; then
  echo "ERROR: invalid sink: \"$sink\""
  exit 1
fi

function _toggle() {
  a=$1
  if [ $(pgrep $a) ]; then
    killall $a
  else
    $a &> /dev/null &
  fi
}

case $1 in
  d*)
    pactl set-sink-volume $sink -5%
    ;;
  i*)
    pactl set-sink-volume $sink +5%
    ;;
  m*)
    pactl set-sink-mute $sink toggle
    ;;
  gui)
    _toggle $app
    ;;
  *)
    echo "ERROR: invalid command: \"$1\""
    ;;
esac