# SANSA E200P playlist maker.
#
# The playlists produced are in the extended M3U format and go in the MUSIC/
# directory. Put imusic files in directories under MUSIC/ and run this script from
# MUSIC/ like so:
#   perl sansa.pl pls foo bar
# This will create playlist (or playlists, see maxcount below) names pls000.M3U
# pls001.M3U etc.  and they will contain files from MUSIC/foo and MUSIC/bar
# directories.
#
# The M3U files go in MUSIC/ and the paths inside them are relative to MUSIC,
# with backslashes as path separator.
#
# 2008-12-25
# Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License
# http://creativecommons.org/licenses/by-nc-sa/3.0/us/
#
# Created by Satya http://www.thesatya.com/

use strict;
use warnings;

my $maxcount=20; # maximum number per playlist, -1 for unlimited.

sub usage {
    print<<EOT;
Usage: $0 prefix directory [list]
EOT
    exit;
}

sub main {
    my $prefix=$ARGV[0] || &usage;
    my @dir=@ARGV;

    shift @dir;

    &usage if $#dir < 0;

    my @list;
    foreach my $dir(@dir) {
        foreach my $entry (&buildlist($dir)) {
            #$entry=~s/^$dir//;
            $entry=~s/^\///;
            $entry=~s/\//\\/g;
            push @list, $entry;
        }
    }
    my $fileop = M3U->new($prefix,$maxcount);
    foreach my $item (@list) {
        $fileop->add($item);
    }
    $fileop->close;

}

sub buildlist {
    my $dir=shift;
    my @list;
    opendir(DIR, $dir) || return ();
    my @files=readdir(DIR);
    closedir(DIR);
    foreach my $file(@files) {
        my $path=$dir . '/' . $file;
        next if $file=~/^\./; # skip hidden and parent directories
        push( @list,&buildlist($path) ) if -d $path; # descend into directory
        next unless (-f $path); # next unless is plain file
        next unless $file=~/mp3$/i;
        push(@list, $path);
    }
    return @list;
}


&main;

package M3U;
sub new($) {
    my $class=shift;
    die "null class" unless $class;
    my $self={};
    $self->{'prefix'} = shift;
    die "no prefix given" unless $self->{'prefix'};
    $self->{'maxcount'}=shift;
    $self->{'opened'}=0;
    $self->{'count'}=0;
    $self->{'filecount'}=0;
    bless $self, $class;
    return $self;
}

sub add($) {
    my $self=shift;
    my $item=shift;
    if($self->{'opened'}==0) {
        $self->open;
    }
    my $name=(split /\\/, $item )[-1];
    my $fh=$self->{'fh'};
    print $fh "#EXTINF:-1,$name\r\n$item\r\n";
    $self->{'count'} += 1;
    if ($self->{'maxcount'} >0 and $self->{'count'} > $self->{'maxcount'}) {
        $self->close;
        $self->{'count'} = 0;
    }
}

sub open {
    my $self=shift;
    my $fname=sprintf("%s%03d.M3U", $self->{'prefix'} , $self->{'filecount'});
    open(FH, ">$fname") || die "$!";
    print FH "#EXTM3U\r\n";
    $self->{'fh'} = *FH{IO};
    $self->{'opened'}=1;
    $self->{'filecount'} += 1;
}

sub close {
    my $self=shift;
    return if $self->{'opened'}==0;
    close($self->{'fh'});
    $self->{'opened'}=0;
}