#!/usr/bin/perl

use strict;

use Audio::FLAC::Header;

my @fields = qw/Title Artist Album Year Comment Genre Tracknumber/;

my ($f, $ok, @files);

# config/defaults
my %config = (
	rename => 1,
);

# process args
while ($f = shift @ARGV) {
	$ok = 0;

	if (-f $f ) { push @files, $f; $ok = 1}

	for (@fields) {
		if ($f =~ /^\-\-no\-$_/i) {
			$config{skip}{$_} = 1;
			$ok = 1;
		} elsif ($f =~ /^\-\-$_/i) {
			$config{default}{$_} = shift @ARGV;
			$ok = 1;
		}
	}

	if ($f eq '--no-rename') {
		$config{rename} = 0;
		$ok = 1;
	}

	die "Unknown tag/no file $f" unless $ok;
}

for (@files) {
	edit_tag($_);
}

sub edit_tag {
	my $file = shift;
	print "$file:\n";

	my ($f, $ftag, $flac, $src, $dst, $newtag, $changed, $skip);

	$flac = Audio::FLAC::Header->new($file);
	die "Can't get FLAC header - $!" unless $flac;

	$ftag = $flac->tags();
	die "Can't get flac tags - $!" unless $ftag;

	$changed = 0;

	for $f (@fields) {
		$skip = exists $config{skip}{$f} ? 1 : 0;
		$f = ((grep /^$f$/i,keys %$ftag)[0] || $f);
		print "\t[$f] ";
		if ($config{default}{$f} || '') {
			print "$config{default}{$f}\n";
			$$ftag{$f} = $config{default}{$f};
			$changed = 1;
			next;
		}
		if (! length($$ftag{$f} || '')) {

			print '("") ';

			if ($skip ) {
				$newtag = ''; print "\n";
			} else {
				print '---> ';
				$newtag = <>;
			}
			chop($newtag);
			if ($newtag =~/\w+/) {
				$$ftag{$f} = $newtag;
				$changed = 1;
			}
		} else { print "$$ftag{$f}\n"; }
		#$$f{ucfirst(lc($_))} = $$m{$_}
	}

	if ($changed) {
		print "*** NEW TAG WRITTEN ***\n";
		$flac->write() || warn $!;
	}

	$dst = $$ftag{Title};
	$dst =~s/[ \:]/_/og;
	$dst =~s/[^\w\-\_]//og;
	$dst = ucfirst(lc($dst)) .'.flac';

	if ($config{rename} && $file ne $dst && ! -e $dst) {
		print "$file -> $dst";
		rename $file, $dst;
	} else { print "$dst exists; not renaming\n"; }
		
	print "\n";
}