#!/usr/bin/perl -w

my $RCS_Id = '$Id: mp3rename.pl,v 1.15 2005/04/03 09:43:20 jv Exp $ ';

# Author          : Johan Vromans
# Created On      : Fri Jan 17 20:47:08 2003
# Last Modified By: Johan Vromans
# Last Modified On: Sun Apr  3 11:40:37 2005
# Update Count    : 97
# Status          : Unknown, Use with caution!

################ Common stuff ################

$VERSION = sprintf("%d.%02d", '$Revision: 1.15 $ ' =~ /: (\d+)\.(\d+)/);

use strict;
use warnings;

# Package name.
my $my_package = 'Sciurix';
# Program name and version.
my ($my_name, $my_version) = $RCS_Id =~ /: (.+).pl,v ([\d.]+)/;
# Tack '*' if it is not checked in into RCS.
$my_version .= '*' if length('$Locker:  $ ') > 12;

################ Command line parameters ################

my $target = "";		# target dir
my $va = 0;			# various artists
my $verbose = 0;		# verbose processing
my $sel;			# only these
my $lconly = 0;			# only lowercase filenames

# Development options (not shown with -help).
my $debug = 0;			# debugging
my $trace = 0;			# trace (show process)
my $test = 0;			# test mode.

# Process command line options.
app_options();

# Post-processing.
$target .= "/" if $target;
$trace |= ($debug || $test);
$verbose |= $test;

################ Presets ################

# my $TMPDIR = $ENV{TMPDIR} || $ENV{TEMP} || '/usr/tmp';

################ The Process ################

use File::Basename;
use File::Path qw(mkpath);
use MP3::Info;

my %dirs;
$sel = qr/$sel/i if $sel;

foreach my $file ( @ARGV ) {

    next if $lconly && $file ne lc($file);

    next unless -f $file;
    my $mp3 = get_mp3tag($file);
    next unless $mp3;

    my $artist = join("_", map { ucfirst lc $_ } split(' ',$mp3->{ARTIST}));
    my $album  = join("_", map { ucfirst lc $_ } split(' ',$mp3->{ALBUM} ));
    my $title  = join("_", map { ucfirst lc $_ } split(' ',$mp3->{TITLE} ));

    $artist ||= "Unknown";
    $album  ||= "Unknown";
    $title  ||= basename($file, ".mp3");

    if ( $va ) {
	$title = $artist . ":_" . $title;
	$artist = "Various";
    }

    my $track  = 0;
    $track = $1 if ($mp3->{TRACKNUM}||"") =~ /^(\d+)/;
    # Try to infer from filename, e.g. "04_Foo.mp4"
    # or "Artist_-_Album_-_04_-_Foo.mp3"
    # or "04._Artist_-_Album_-_Foo.mp3"
    $track = $1 if !$track && $file =~ /(?:^|\/|_| )(\d{1,2})\.?[_ ][^\/]*$/;
    $title = sprintf("%02d_%s", $track, $title) if $track;
    # Sometimes the track is also part of the title. Strip.
    $title =~ s/^(\d+)_\1[-_]/$1_/;
    # Some normalisations.
    for ( $title, $artist, $album ) {
	s/_\(([a-z])/"_(".uc($1)/ge;
	s/_\[([a-z])/"_[".uc($1)/ge;
	s/-([a-z])/"-".uc($1)/ge;
	s/[\/"\`?!]/_/g;
	s/__+/_/g;
	s/^_//;
	s/_$//;
    }
    my $dir = join("/", $artist, $album);
    next if $sel && $dir !~ $sel;
    warn("+ rename $file => $target$dir/$title.mp3\n") if $verbose > 1;
    if ( -s "$target$dir/$title.mp3" ) {
	if ( differ($file, "$target$dir/$title.mp3") ) {
	    warn("ERROR: Differing $target$dir/$title.mp3 already exists\n");
	}
	else {
	    warn("WARNING: Identical $target$dir/$title.mp3 already exists\n");
	    unlink($file);
	}
    }
    else {
	unless ( -d "$target$dir" ) {
	    if ( $test ) {
		warn("mkdir $target$dir\n")
		  if $verbose && !$dirs{"$target$dir"}++;
		next;
	    }
	    mkpath(["$target$dir"],$verbose,0775);
	}
	next if $test;
	rename($file, "$target$dir/$title.mp3")
	  or warn("+ rename $file => $target$dir/$title.mp3\n".
		  "ERROR: $!\n");
    }
}

################ Subroutines ################

sub differ {
    # Perl version of the 'cmp' program.
    # Returns 1 if the files differ, 0 if the contents are equal.
    my ($old, $new) = @_;
    unless ( open (F1, $old) ) {
	print STDERR ("$old: $!\n");
	return 1;
    }
    unless ( open (F2, $new) ) {
	print STDERR ("$new: $!\n");
	return 1;
    }
    my ($buf1, $buf2);
    my ($len1, $len2);
    while ( 1 ) {
	$len1 = sysread (F1, $buf1, 10240);
	$len2 = sysread (F2, $buf2, 10240);
	return 0 if $len1 == $len2 && $len1 == 0;
	return 1 if $len1 != $len2 || ( $len1 && $buf1 ne $buf2 );
    }
}

################ Subroutines ################

################ Command Line Options ################

use Getopt::Long 2.33;		# will enable help/version

sub app_options {
    my $help = 0;		# handled locally
    my $ident = 0;		# handled locally

    GetOptions(ident	=> \&app_ident,
	       'verbose|v+' => \$verbose,

	       # application specific options go here
	       'target=s' => \$target,
	       va	=> \$va,
	       'select=s' => \$sel,

	       # development options
	       test	=> \$test,
	       trace	=> \$trace,
	       debug	=> \$debug)
      or Getopt::Long::HelpMessage(2);
}

sub app_ident {
    print STDERR ("This is $my_package [$my_name $my_version]\n");
}

1;

__END__

=head1 NAME

mp3rename - Rename MP3 files according to ID3 information

=head1 SYNOPSIS

rename_mp3 [options] [file ...]

Options:

    --target XXX	target dir
    --various-artists	use "Various/Album/Artist:_Title"
    --select XXX	selective operation
    --lc		lowercase filenames only
    --test		show what would have been done, but don't do it
    --help		this message
    --ident		show identification
    --verbose		increase verbose information

=head1 OPTIONS

=over 8

=item B<--target> I<XXX>

The target directory where the files are renamed into. Default is
relative to the current directory.

=item B<--select=>I<XXX>

Select only entries that will be renamed to directories (i.e.,
Artist/Album) that match the pattern.

=item B<--lc>

Select only entries that do not contain uppercase (or mixed case)
characters.

=item B<--various-artists>

Use an alternative form for the file name, suitable for albums that
contain tracks of various artists. See L<DESCRIPTION>.
Note that you can abbreviate this conveniently to B<--va>.

=item B<--test>

Show what would have been done, but don't do it.

=item B<--verbose>

Show what is being done. Can be specified multiple times to increase
verbosity.

=item B<--version>

Print a version identification to standard output and exits.

=item B<--help>

Print a brief help message to standard output and exits.

=item B<--ident>

Prints a program identification before proceeding.

=back

=head1 DESCRIPTION

B<mp3rename> will read the ID3 information from the given input
file(s) and use it to rename the file(s) to a standardized name.
Care is taken to not overwrite existing files.

Default file name format is
I<Artist>/I<Album_Title>/I<Track_Number>_I<Track_Title>.mp3.

With B<--various-artists> selected:
Various/I<Album_Title>/I<Artist>:_I<Track_Number>_I<Track_Title>.mp3.

Attempts are made to sanitize the filename components: underscores
instead of spaces, all words titlecased, and problematic characters
avoided. Track numbers are always two digits.

=head1 AUTHOR

Johan Vromans <jvromans@squirrel.nl>

=head1 COPYRIGHT

This programs is Copyright 2003,2005 Squirrel Consultancy.

This program is free software; you can redistribute it and/or modify
it under the terms of the Perl Artistic License or 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.

=cut