#!/usr/bin/perl -w
# mp3_tag_fix
# Max Baker <max@warped.org>
# 4/5/09

$VERSION=1.1;

use File::Glob qw(:globally :glob);
use Audio::TagLib;
use Getopt::Long;
GetOptions (\%Args, "h|help", "f|front=s", 'b|back=s',
            'c|covers|addcovers','v1tov2', 'comp|compilation');

$Cover_Front = $Args{f} || "Folder.jpg";
$Cover_Back  = $Args{b} || "Folder_back.jpg";

die &usage if (! scalar @ARGV or $Args{h});
die &usage unless ($Args{c} || $Args{v1tov2} || $Args{comp});

foreach my $f (@ARGV) {
    if (-d $f) {
        recurse_dir($f);
        next;
    }
    go($f);
}

exit;

sub go {
    my $f = shift;

    # Only work on files that end in .mp3
    return if $f eq '.';
    return if $f eq '..';
    return unless -r $f and $f =~ /\.mp3$/i;

    print "  $f\n";

    my $mp3 = Audio::TagLib::MPEG::File->new($f) or die;
    my $id3v1 = $mp3->ID3v1Tag(1);
    my $id3v2 = $mp3->ID3v2Tag(1);

    # Cover Art
    if ($Args{c}) {
        #print "    --> Adding Cover Art\n";
        add_image($id3v2,$f,"$root/$Cover_Front","FrontCover","Cover (front)") if -r "$root/$Cover_Front";
        add_image($id3v2,$f,"$root/$Cover_Back", "BackCover", "Cover (back)")  if -r "$root/$Cover_Back";
    }

    # Copy v1 tags to v2
    if ($Args{v1tov2}) {
        print "    --> Copying ID3v1 data to ID3v2\n";
        $id3v2->setArtist(Audio::TagLib::String->new($id3v1->artist)) if nb($id3v1->artist);
        $id3v2->setAlbum(Audio::TagLib::String->new($id3v1->album))  if nb($id3v1->album);
        $id3v2->setTitle(Audio::TagLib::String->new($id3v1->title))  if nb($id3v1->title);
        $id3v2->setYear($id3v1->year)                                if nb($id3v1->year);
        $id3v2->setTrack($id3v1->track)                              if nb($id3v1->track);
        $id3v2->setGenre(Audio::TagLib::String->new($id3v1->genre))  if nb($id3v1->genre);
    }

    # Add/Replace TCMP - Compilation Tag
    if ($Args{comp}) {
        print "    --> Setting Compilation Flag\n";
        my $tcmp = Audio::TagLib::ByteVector->new("TCMP");
        $id3v2->removeFrames($tcmp);

        #my $f = Audio::TagLib::ID3v2::TextIdentificationFrame->new($tcmp, "UTF8");
        my $f = Audio::TagLib::ID3v2::TextIdentificationFrame->new($tcmp);
        $f->setText(Audio::TagLib::String->new("1"));
        $id3v2->addFrame($f);
    }

    $mp3->save();
}

sub recurse_dir {
    my $root = shift;

    print "Entering $root\n";

    # bsd_glob handles spaces in file names/paths
    my @files = bsd_glob("$root/*",GLOB_QUOTE);
    foreach my $f (@files) {
        if (-d $f) {
            recurse_dir($f);
            next;
        }
        go($f);
    }
}

# not blank or undef
sub nb {
    my $string = shift;
    return 0 unless defined $string;
    return 0 if $string =~ /^\s*$/;
    return 1;
}

sub add_image {
    my ($id3v2,$f,$img,$type,$desc) = @_;

    print "    --> add_image($type) $img -> $f\n";

    open(PICFILE, "<$img") or die "Can't open image $img. $!\n";

    my $imgdata;
    my $filesize = -s PICFILE;
    binmode(PICFILE);
    read(PICFILE, $imgdata, $filesize);
    close(PICFILE);

    my $imgbv = Audio::TagLib::ByteVector->new();
    $imgbv->setData($imgdata,$filesize);
    my $bv = Audio::TagLib::ByteVector->new("APIC");
    my $field = Audio::TagLib::ID3v2::AttachedPictureFrame->new($bv, "UTF8");
    $field->setPicture($imgbv);
    $field->setTextEncoding("UTF8");
    $field->setMimeType(Audio::TagLib::String->new("image/jpeg"));
    $field->setType($type);
    $field->setDescription(Audio::TagLib::String->new($desc));
    $id3v2->addFrame($field);
}

sub usage {
    return << "end_usage";
USAGE: $0 <dir> <cmd> [options]

mp3_tag_fix Version $VERSION

This script is used to fix up MP3 files for use in iTunes.

It can do the following things :
    * Recursively go through a directory and embed album art 
    * Copy ID3v1 tag data into ID3v2

<COMMANDS>
    -c | --addcovers - Embed $Cover_Front / $Cover_Back into the MP3
    --v1tov2         - Copy ID3v1 Tags into ID3v2 Tag
    --comp           - Set iTunes Compilation flag (TCMP)

[OPTIONS]
    -f - The name of the image to look for in each dir to embed front-covers
    -b - The name of the image to look for in each dir to embed back-covers

Max Baker <max\@warped.org> 4/6/2009
end_usage
}