suspends the computer using systemctl suspend when music on mpd is paused, needs mpc

mpd-suspend-on-pause

#!/bin/bash
#suspends the computer when mpd gets paused
if ! command -v > /dev/null mpc
then
    echo "error: this needs mpc to be installed"
    exit 1
fi
uid=$(id -u)
pidfile="/var/run/user/$uid/mpd-suspend-on-pause.pid"
if [[ "$1" == "-k" ]] # kill
then
    if [[ -f $pidfile ]]
    then
        (kill "$(cat $pidfile)" 2> /dev/null) || (>&2 echo "not running";exit 1)
    fi
elif [[ "$1" == "-s" ]] # status
then
    if [[ -f $pidfile ]] && ps $(cat $pidfile) > /dev/null;
    then
        echo "running"
    else
        echo "not running"
    fi
else
    if [[ -f $pidfile ]] && ps $(cat $pidfile) > /dev/null;
    then
        (>&2 echo "already running")
        exit 1
    else
        while (true)
        do
            mpc idle > /dev/null
            if [[ ! $(mpc status | grep playing) ]]
            then
                systemctl suspend -i
                break
            fi
        done &
        echo "$!" > $pidfile
    fi
fi