#!/usr/bin/perl

use warnings;
use strict;

######################################################################
#
# BCE Project 19, Exercise accessing nested data
#
# Search for *.mp3, build structure of each mp3's info.
#
# print structured info
#

my $Filename = '\*.mp3';
my $MusicRoot = '/Your/Music/Location'; # no trailing slash

# REQUIRES TagLib 1.5 avaliable at 
# REQUIRES Audio-TagLib-1.50_01 avaliable at cpan.org
use Audio::TagLib::MPEG::Properties;

use Data::Dumper;             # For testing
$Data::Dumper::Indent = 1;    # For testing

# Subs expect (Audio::TagLib::MPEG::File->new('Filename'))
sub _Get_Artist     { my $t = shift; return $t->tag()->artist()->toCString(); }
sub _Get_Album      { my $t = shift; return $t->tag()->album()->toCString(); }
sub _Get_Title      { my $t = shift; return $t->tag()->title()->toCString(); }
sub _Get_Comment    { my $t = shift; return $t->tag()->comment()->toCString(); }
sub _Get_Genre      { my $t = shift; return $t->tag()->genre()->toCString(); }
sub _Get_Year       { my $t = shift; return $t->tag()->year(); }
sub _Get_Track      { my $t = shift; return $t->tag()->track(); }
sub _Get_Length     { my $t = shift; return $t->audioProperties->length(); }
sub _Get_Bitrate    { my $t = shift; return $t->audioProperties->bitrate(); }
sub _Get_Samplerate { my $t = shift; return $t->audioProperties->sampleRate(); }
sub _Get_Channels   { my $t = shift; return $t->audioProperties->channels(); }

# Sub expects ('Filename')
sub HashMPEG
{
  my $f = shift;

  my %Artist;
  my %Album;
  my %Title;
  my %TagInfo;
  my $m = Audio::TagLib::MPEG::File->new($f);
  my %TagsMPEG = ('comment' => \&_Get_Comment, 'genre' => \&_Get_Genre, 'year' => \&_Get_Year, 'track' => \&_Get_Track, 'length' => \&_Get_Length, 'bitrate' => \&_Get_Bitrate, 'samplerate' => \&_Get_Samplerate, 'channels' => \&_Get_Channels);
  for my $t (keys %TagsMPEG) {
    $TagInfo{$t} = $TagsMPEG{$t}->($m);
  }
  $Title{_Get_Title($m)} = \%TagInfo;
  $Album{_Get_Album($m)} = \%Title;
  $Artist{_Get_Artist($m)} = \%Album;
  return \%Artist;
}

sub HashFiles
{
  my $d = shift;
  my $f = shift;

  my %FH;
  my @flist = `find $d -type f -name $f`;
  if ($#flist) {
    for my $t (@flist) {
      chomp $t;
      $FH{$t} = HashMPEG $t;
    }
  }
  return %FH;
}

my %FilesHash = HashFiles $MusicRoot, $Filename;

# for testing
#print Dumper(\%FilesHash);

for my $File (keys %FilesHash) {
  print "File        : " . $File . "\n";
}

##</code><code>##

File       : /Common/Music/Stevie Ray Vaughan and Double Trouble/Live Alive/03-Pride and Joy.mp3
Artist     : Stevie Ray Vaughan and Double Trouble
Album      : Live Alive
Title      : Pride and Joy
Comment    :
Genre      : Blues
Year       : 1986
Track      : 3
Length     : 304
Bitrate    : 256
Samplerate : 44100
Channels   : 2

##</code><code>##

  '/mnt/RaidOne/Music/Stevie Ray Vaughan and Double Trouble/Live Alive/03-Pride and Joy.mp3' => {
    'Stevie Ray Vaughan and Double Trouble' => {
      'Live Alive' => {
        'Pride and Joy' => {
          'bitrate' => 256,
          'channels' => 2,
          'track' => 3,
          'samplerate' => 44100,
          'genre' => 'Blues',
          'length' => 304,
          'comment' => '',
          'year' => 1986
        }
      }
    }
  },