#!/usr/bin/perl

use strict;
use warnings;

use File::Find::Rule qw( );
use Path::Class      qw( file );

die "Usage: $0 path/to/search\n"
   if @ARGV != 1 || !-d $ARGV[0];

my @scan = File::Find::Rule
   ->name(qr/\.mp3\z/i)
   #->file
   ->in( $ARGV[0] );

my $last_dir = '';
my $fh;

for (@scan) {
   my $file = file($_);
   my $dir = $file->dir;

   if ($dir ne $last_dir) {
      $dir = $last_dir;

      my $m3u = $dir->dir_list(-1);
      $m3u =~ s/[\s.']+//g;
      $m3u = $dir->file("$m3u.m3u");

      open($fh, '>', $m3u)
         or warn("Unable to create \"$m3u\": $!\n");
   }

   print($fh "$_\n");
}