#!/usr/bin/perl
#
# Vorbiscomment from Filename
#   usage: vcfromfilename [options] <files>
#   options:
#     -n:  Only set the track number
#     -0:  Leading 0s in track number are preserved
#     -T:  Tag names (not tag content) written to the metadata in all caps
#
# Adds Vorbiscomment data to ogg vorbis and flac files based on the filename.
# Files should be in Anna's arbitrary file name standard, which is:
# artist/album/artist-tracknum-title.(ogg|flac|mp3)
#
# The top-level directory (artist) is optional.  Filenames should contain no
# spaces; underscores in the filename are converted to spaces in the resulting
# metadata
#
# Requires vorbiscomment and metaflac
#
# Changelog:
# 0.2.4: added -T option
#        added releasedate support through MusicBrainz
#        added mp3 support and refactored code heavily
#        added -y option to explicitly look for the year
# 0.2.3: added documentation, -0 command-line option
# 0.2.2: added flac support, documentation
# 0.2.1: fixed version in help message
#        fixed handling of dashes in artist name and title
# 0.2:   aligned version with ds-audiotools
# 0.1.1: added version variable
# 0.1:   initial implementation

$VERSION = "0.2.4";
$HELP_MSG = "Vorbiscomment from Filename $VERSION\n\tusage: vcfromfilename [options] <files>\n\nValid options:\n\t-n\tOnly set the track numbers\n\t-0\tPreserve leading 0s in track numbers\n\t-T: Write tag names (not tag content) in all caps\n";


use Music::Tag;

chomp($COMMENTFILENAME = '/tmp/vcfromfilename-' . `whoami`);

# Look for options
foreach (@ARGV)
{
    if (/^(-h)|(--help)$/) { die $HELP_MSG; }
    elsif (/^-n$/) { $tracknumonly = true; s/.*//g; }
    elsif (/^-T$/) { $captagnames = true; s/.*//g; }
    elsif (/^-0$/) { $extrazero = true; s/.*//g; }
    elsif (/^-y$/) { $get_year = true; s/.*//g; }
    else { push @tracks, $_; }
}

# Set the mode
if ($tracks[0] =~ /\.flac$/) { $mode = 'flac'; }
elsif ($tracks[0] =~ /\.mp3$/) { $mode = 'mp3'; }
elsif ($tracks[0] =~ /\.ogg$/) { $mode = 'ogg'; }
else { die "Couldn't detect mode"; }


# Set the album name
$album = `pwd`; # We WANT the newline here
$album =~ s/^.*\///; # Remove everything up to the last /
$album = formatName($album, 'album=', $captagnames, $mode);


# Try to find the release date
$year;

if ($get_year)
{
    $mbinfo = Music::Tag->new($tracks[0]);
    
    if ($mode eq 'ogg') { $mbinfo->add_plugin($mbinfo->plugin("OGG")); }
    elsif ($mode eq 'flac') { $mbinfo->add_plugin($mbinfo->plugin("FLAC")); }
    elsif ($mode eq 'mp3') { $mbinfo->add_plugin($mbinfo->plugin("MP3")); }

    $mbinfo->add_plugin("MusicBrainz");
    $mbinfo->get_tag();

    $year = formatName($mbinfo->year, 'year=', $captagnames, $mode);
}



# Parse the file list, set comments
foreach (@ARGV)
{
    next if (/^$/);
    # check filename format
    next unless (/^\w+-\d{1,2}-(\w|-|\d)+\.(ogg|flac|mp3)$/);

    if ($mode eq 'flac' || $mode eq 'ogg')
    {
	open COMMENTFILE, '>' . $COMMENTFILENAME;
    }


    # Remove old comments
    if ($mode eq 'flac')
    {
	system("metaflac --remove-tag=TRACKNUMBER $_");
	system("metaflac --remove-tag=tracknumber $_");
	if (!$tracknumonly)
	{
	    system("metaflac --remove-tag=TITLE --remove-tag=ARTIST --remove-tag=ALBUM --remove-tag=YEAR $_");
	    system("metaflac --remove-tag=title --remove-tag=artist --remove-tag=album --remove-tag=year $_");
	}
    }
    elsif ($mode eq 'mp3')
    {
	system("id3v2 -D $_");
    }
    # For ogg, preserve existing comments, except the ones we'll replace
    else
    {
	foreach (`vorbiscomment -l $_`)
	{
		if ($tracknumonly) { print COMMENTFILE $_ unless (/^tracknumber/i); }
		else { print COMMENTFILE $_ unless (/^(title)|(artist)|(tracknumber)|(album)|(year)/i); }
	}
    }

    # Create new comments from the filename
    if (!$tracknumonly)
    {
	# Add the artist
	$artist = $_;
	$artist =~ s/^(.*?)-\d{2}-.*/\1/; # grab everything to the track number
	$artist = formatName($artist, 'artist=', $captagnames, $mode);
	
	# Add the title
	$title = $_;
	$title =~ s/.*-\d{2}-(.*)\.(ogg|flac|mp3)$/\1/; # grab everything after the track number
	$title = formatName($title, 'title=', $captagnames, $mode);

	# For some modes, print everything to a comment file
	if ($mode eq 'flac' || $mode eq 'ogg')
	{
	    print COMMENTFILE $year;
	    print COMMENTFILE $artist;
	    print COMMENTFILE $title;
	    print COMMENTFILE $album;
	}
    }

    # Now get the track number
    my $tracknum = $_;
    $tracknum =~ s/.*-(\d{2})-.*/\1/;
    if (!$extrazero) { $tracknum =~ s/\b0*//; } # removing leading zeros
    $tracknum = formatName($tracknum, 'tracknumber=', $captagnames, $mode);

    if ($mode eq 'flac' || $mode eq 'ogg')
    {
	print COMMENTFILE $tracknum;
        close COMMENTFILE;
    }

    if ($mode eq 'flac') { system("metaflac --import-tags-from=$COMMENTFILENAME $_"); }
    elsif ($mode eq 'mp3')
    { 
	$tags = "";
	$tags .= "-T $tracknum" if $tracknum;

	if (!$tracknumonly)
	{
	    $tags .= " -a '$artist'" if $artist;
	    $tags .= " -t '$title'" if $title;
	    $tags .= " -A '$album'" if $album;
	    $tags .= " -y $year" if $year;
	}

	system("id3v2 $tags $_");
    }
    elsif ($mode eq 'ogg')
    {
	system("vorbiscomment -c $COMMENTFILENAME -w $_");
    }

    if ($mode eq 'flac' || $mode eq 'ogg') { system('rm', $COMMENTFILENAME); }
}



# Formats the first argument, adds the second argument to it
# If the third argument is true, the second argument is converted
# to upper case
sub formatName
{
    my $name = shift;
    my $prepend = shift;
    my $upper = shift;
    my $mode = shift;
    if ($upper) { $prepend = uc($prepend); }
    chomp $name; # we add a newline ourselves
    $name =~ s/_/ /g; # underscore - space
    $name =~ s/^\s*//; # Remove leading space
    $name =~ s/\s*$//; # Remove trailing space
    $name =~ s/\b(\w)/uc($1)/eg; # Cap the words

    if ($mode eq 'flac' || $mode eq 'ogg')
    {
	$name = $prepend . $name . "\n";
    }

    return $name;
}


# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA