Plays music randomly with some random pauses

random-music.bash

#!/bin/bash

rand()
{
    low=0
    high=0
    if [[ $# -eq 1 ]]; then
        high=$1
    elif [[ $# -eq 2 ]]; then
        low=$1
        high=$2
    fi

    echo $(( RANDOM % (high - low + 1) + low ))
}

s_to_hms()
{
    if [[ $# -ne 1 ]]; then
        echo "s_to_hms: I need 1 argument: seconds" 1>&2
        return 1
    fi
    diff_s=$1
    h=$((diff_s/3600))
    diff_s=$((diff_s - diff_s/3600*3600))
    m=$(tail -c 3 <<< 0$((diff_s/60)))
    diff_s=$((diff_s - diff_s/60*60))
    s=$(tail -c 3 <<< 0$diff_s)
    echo "$h:$m:$s"
}


if [[ $# -eq 0 ]]; then
    echo "I want one or more arguments: filename(s)" 1>&2
    exit
fi

mpv_args=''
if [[ -n "$volume" ]]; then
    mpv_args="$mpv_args --volume=$volume"
fi

space_low=0$(echo $space | grep -o '^[0-9]*')
space_high=0$(echo $space | grep -o '[0-9]*$')
pause_low=0$(echo $pause | grep -o '^[0-9]*')
pause_high=0$(echo $pause | grep -o '[0-9]*$')
duration=0$duration
if [[ $space_high -eq 0 ]]; then
    space_low=1
    space_high=1
fi
if [[ $pause_high -eq 0 ]]; then
    pause_low=60
    pause_high=120
fi
if [[ $duration -eq 0 ]]; then
    duration=$((60*15))
fi

files=''
while [[ $# -gt 0 ]]; do
    files="$files"$(find -L "$1" -type f)$'\n'
    shift
done

last_pause=$(date +%s)
while true; do
    random_file=$(echo -n "$files" | sort -R | head -n1)
    mpv $mpv_args "$random_file"
    played_time=$(($(date +%s)-last_pause))
    if [[ $played_time -gt $duration ]]; then
        echo "That was $(s_to_hms $played_time) played" 1>&2
        delay=$(rand $pause_low $pause_high)
        echo "Pausing $(s_to_hms $delay)" 1>&2
        sleep $delay
        last_pause=$(date +%s)
    else
        delay=$(rand $space_low $space_high)
        sleep $delay
    fi
done