#!/usr/bin/perl -w

use strict;
use feature qw(say);
use String::ShellQuote;

my $file = shell_quote($ARGV[0]);
my $out = $ARGV[1];
my $title = $ARGV[2];
my $ffprobe = "/usr/bin/ffprobe";
open(my $h, "-|", "$ffprobe $file 2>&1") or die "horribly";
my $duration;
while(<$h>){
	if(m#Duration: (\d+:\d+:\d+)\..*#){
		$duration = $1;
		last;
	}
}
my ($hours, $minutes, $seconds) = split(':', $duration);
my $numtracks = ($hours * 60 + $minutes) / 20 + 1;
my $ctr = 1;
my $last = 0;
my $splitat = "-t 00:20:00";
for (my $i = 0; $i <= $hours; $i++){
	for(my $j = 0; $j < 60; $j += 20){
		my $start = sprintf("%02i:%02i:00", $i, $j);
		if($i == $hours and  $j + 20 > $minutes){
			#$end = sprintf("%02i:%02i:00", $i, $minutes + 1);
			$splitat = " ";
			$last = 1;
		}
		my $trackno = sprintf("%02i", $ctr);
		my $outname = sprintf("%s - %02i.mp3", $out, $ctr);
		my $titstr = sprintf("%s - %02i of %02i", $title, $ctr, $numtracks);
		say "ffmpeg -ss $start -i $file -acodec copy -vn $splitat -metadata track=\"$trackno\" -metadata title=\"$titstr\" \"$outname\"";
		last if($last);
		$ctr++;
	}
}