#!/opt/local/bin/perl
use warnings;
use strict;
use Music::Tag;
use File::Slurp;

my @FILES = ();

my $tmpl = '{{track-number-pad}} - {{artist}} - {{track-name}}';

if (defined $ARGV[0] && -f $ARGV[0] && $ARGV[0] =~ m/\.m3u$/gi) {
    @FILES = grep { /\.(mp3|ogg|m4a)$/i } grep { /^[^#]/ } read_file($ARGV[0]);
    if (defined $ARGV[1]) {
        $tmpl = $ARGV[1]
    }
} else {
    while (my $lod = <STDIN>) {
        push @FILES, $lod;
    }
    if (defined $ARGV[0]) {
        $tmpl = $ARGV[0]
    }
}

chomp(@FILES);

foreach my $f (@FILES) {
    my $info = Music::Tag->new($f, {quiet=>1});
    $info->get_tag();
    my $tmpl_i = $tmpl;

    my $md_track = int($info->track || 0);
    my $md_track_padded = sprintf('%02d', $md_track) || '00';
    my $md_title = $info->title || 'UNKNOWN';
    my $md_album = $info->album || 'UNKNOWN';
    my $md_artist = $info->artist || 'UNKNOWN';
    my $md_year = $info->year || 'UNKNOWN';
    my $md_file = $f;
    my $md_ext = $f;
    $md_ext =~ s/^.+?\.(mp3|ogg|m4a)$/$1/gi;

    $tmpl_i =~ s/{{track-number}}/$md_track/gi;
    $tmpl_i =~ s/{{track-number-pad}}/$md_track_padded/gi;
    $tmpl_i =~ s/{{track-name}}/$md_title/gi;
    $tmpl_i =~ s/{{album}}/$md_album/gi;
    $tmpl_i =~ s/{{artist}}/$md_artist/gi;
    $tmpl_i =~ s/{{year}}/$md_year/gi;
    $tmpl_i =~ s/{{file}}/$md_file/gi;
    $tmpl_i =~ s/{{ext}}/$md_ext/gi;

    print "$tmpl_i\n";
}