control filters via $ENABLE_FILTER at the top of ID3FS::Path
[id3fs.git] / lib / ID3FS / Path.pm
1 package ID3FS::Path;
2
3 use strict;
4 use warnings;
5 use ID3FS::Path::Node;
6
7 our ($STATE_INVALID, $STATE_ROOT, $STATE_TAG, $STATE_TAGVAL,
8      $STATE_BOOLEAN, $STATE_ALBUMS, $STATE_TRACKLIST,
9      $STATE_FILE, $STATE_ALL)=(0..8);
10
11 our %priorities=( "OR" => 0, "AND" => 1, "NOT" => 2 );
12
13 our $PATH_ALLTRACKS= "TRACKS";
14 our $PATH_NOARTIST = "NOARTIST";
15 our $PATH_NOALBUM  = "NOALBUM";
16
17 our $ENABLE_FILTER = 1;
18
19 sub new
20 {
21     my $proto=shift;
22     my $class=ref($proto) || $proto;
23     my $self={};
24     bless($self,$class);
25
26     $self->{elements}=[];
27     $self->{db}=shift;
28     $self->{path}=shift;
29     $self->{verbose}=shift;
30     $self->{maxtagdepth}=shift;
31     $self->{curtagdepth}=0;
32     $self->{path} =~ s/\/\//\//g; # drop doubled slashes
33
34     $self->parse();
35 #    print "STATE: ", $self->state(), "\n";
36     return $self;
37 }
38
39 sub isdir
40 {
41     my($self)=@_;
42     if(($self->state() == $STATE_FILE) ||
43        ($self->state() == $STATE_INVALID))
44     {
45         return 0;
46     }
47     return 1;
48 }
49
50 sub isfile
51 {
52     my($self)=@_;
53     return($self->state() == $STATE_FILE);
54 }
55
56 sub isvalid
57 {
58     my($self)=@_;
59     return($self->state() != $STATE_INVALID);
60 }
61
62 sub dest
63 {
64     my($self, $mountpoint)=@_;
65     if($self->state() == $STATE_FILE)
66     {
67         return $self->filename($mountpoint);
68     }
69     return "ERROR"; #should never happen?
70 }
71
72 sub dirents
73 {
74     my($self)=@_;
75     my @dents=();
76     my @fents=();
77     my $state=$self->state();
78 #    print "DIRENTS: STATE: $state\n";
79 #    print "DIRENTS: FILE: $self->{path}\n";
80     if($state==$STATE_ALL)
81     {
82         @dents=($PATH_ALLTRACKS, $PATH_NOARTIST, $self->artists());
83     }
84     elsif($state==$STATE_TAG || $state==$STATE_TAGVAL)
85     {
86         if($state==$STATE_TAG && $self->at("tag") &&
87            $self->{db}->tag_has_values($self->tail()->id()))
88         {
89             @dents=$self->tags();
90         }
91         else
92         {
93             if($self->{maxtagdepth} && ($self->{curtagdepth} < $self->{maxtagdepth}))
94             {
95                 @dents=qw(AND OR);
96             }
97             push(@dents, ($ENABLE_FILTER ?
98                           $self->filter($PATH_ALLTRACKS, $PATH_NOARTIST) :
99                           ($PATH_ALLTRACKS, $PATH_NOARTIST)));
100             push(@dents, $self->artists());
101         }
102     }
103     elsif($state==$STATE_BOOLEAN)
104     {
105         my $parent=$self->tail();
106         unless($self->is("boolean", $parent) &&
107                $parent->{name} eq "NOT")
108         {
109             @dents=("NOT");
110         }
111         push(@dents,$self->tags());
112     }
113     elsif($state==$STATE_ROOT)
114     {
115         @dents=(qw(ALL NOT), $self->tags());
116     }
117     elsif($state==$STATE_ALBUMS)
118     {
119         @dents=($self->filter($PATH_ALLTRACKS, $PATH_NOALBUM), $self->albums());
120     }
121     elsif($state==$STATE_TRACKLIST)
122     {
123         @fents=$self->tracks();
124     }
125     else
126     {
127         print "DIRENTS: UNHANDLED STATE: $state\n";
128     }
129     return(\@dents, \@fents);
130 }
131
132 sub parse
133 {
134     my($self)=@_;
135     @{$self->{components}}=split(/\//, $self->{path});
136     shift @{$self->{components}}; # drop empty field before leading /
137 #    print "PATH: $self->{path}\n";
138     $self->state($STATE_ROOT);
139     return if($self->{path} eq "/");
140     my @parts=@{$self->{components}};
141     my($tag, $tagval);
142     $self->{elements}=[];
143     $self->{in_all}=0;
144     my $root_not=0;
145     my $tags_seen=0;
146     while(defined(my $name=shift @parts))
147     {
148 #       print "NAME: $name\n";
149         my $state=$self->state();
150         if($state==$STATE_INVALID)
151         {
152 #           print "SM: INVALID: $name\n";
153             return;
154         }
155         elsif($state==$STATE_ROOT)
156         {
157 #           print "SM: ROOT: $name\n";
158             if($name eq "ALL")
159             {
160                 $self->{in_all}=1;
161                 $self->state($STATE_ALL);
162             }
163             elsif($name eq "NOT")
164             {
165                 $root_not=1;
166                 push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, "boolean", $name));
167                 $self->state($STATE_BOOLEAN);
168             }
169             else
170             {
171                 $tag=ID3FS::Path::Node->new($self->{db},"tag", $name);
172                 if($tag)
173                 {
174                     push(@{$self->{elements}}, $tag);
175                     $tags_seen++;
176                     $self->state($STATE_TAG);
177                 }
178                 else
179                 {
180                     $self->state($STATE_INVALID);
181                 }
182             }
183         }
184         elsif($state==$STATE_TAG || $state==$STATE_TAGVAL)
185         {
186             my $tag=$self->tail();
187 #           print "SM: TAG/TAGVAL($state): $name\n";
188             if($state==$STATE_TAG && $self->is("tag", $tag) &&
189                $self->{db}->tag_has_values($tag->id()))
190             {
191 #               print "Parsing: parent: $tag->id()\n";
192                 my $tagval=ID3FS::Path::Node->new($self->{db}, "tag", $name, $tag->id());
193                 if(defined($tagval))
194                 {
195                     $self->state($STATE_TAGVAL);
196                     # stay in tag state
197                     push(@{$self->{elements}}, $tagval);
198                 }
199                 else
200                 {
201                     $self->state($STATE_INVALID);
202                 }
203             }
204             elsif($name eq $PATH_ALLTRACKS)
205             {
206                 $self->state($STATE_TRACKLIST);
207             }
208             elsif($name eq $PATH_NOARTIST)
209             {
210                 $self->state($STATE_TRACKLIST);
211             }
212             elsif($name eq "AND")
213             {
214                 $self->state($STATE_BOOLEAN);
215                 push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, "boolean", $name));
216             }
217             elsif($name eq "OR")
218             {
219                 $self->state($STATE_BOOLEAN);
220                 push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, "boolean", $name));
221             }
222             else
223             {
224                 my $artist=ID3FS::Path::Node->new($self->{db}, "artist", $name);
225                 if($artist)
226                 {
227                     push(@{$self->{elements}}, $artist);
228                     $self->state($STATE_ALBUMS);
229                 }
230                 else
231                 {
232                     $self->state($STATE_INVALID);
233                 }
234             }
235         }
236         elsif($state==$STATE_BOOLEAN)
237         {
238 #           print "SM: BOOLEAN: $name\n";
239             my $parent=$self->tail();
240             my $allownot=1;
241             if($self->is("boolean", $parent) &&
242                $parent->{name} eq "NOT")
243             {
244                 $allownot=0;
245             }
246             if($allownot && $name eq "NOT")
247             {
248                 $self->state($STATE_BOOLEAN);
249                 push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, "boolean", $name));
250             }
251             else
252             {
253                 my $tag=ID3FS::Path::Node->new($self->{db}, "tag", $name);
254                 if($tag)
255                 {
256                     push(@{$self->{elements}}, $tag);
257                     $tags_seen++;
258                     $self->state($STATE_TAG);
259                 }
260                 else
261                 {
262                     $self->state($STATE_INVALID);
263                 }
264             }
265         }
266         elsif($state==$STATE_ALBUMS)
267         {
268 #           print "SM: ALBUM: $name\n";
269             if($name eq $PATH_ALLTRACKS)
270             {
271                 $self->state($STATE_TRACKLIST);
272             }
273             elsif($name eq $PATH_NOALBUM)
274             {
275                 $self->state($STATE_TRACKLIST);
276             }
277             else
278             {
279                 my $album=ID3FS::Path::Node->new($self->{db}, "album", $name);
280                 if($album)
281                 {
282                     push(@{$self->{elements}}, $album);
283                     $self->state($STATE_TRACKLIST);
284                 }
285                 else
286                 {
287                     $self->state($STATE_INVALID);
288                 }
289             }
290         }
291         elsif($state==$STATE_TRACKLIST)
292         {
293 #           print "SM: TRACKLIST: $name\n";
294             my $track=ID3FS::Path::Node->new($self->{db}, "file", $name);
295             if($track)
296             {
297                 push(@{$self->{elements}}, $track);
298                 $self->state($STATE_FILE);
299             }
300             else
301             {
302                 $self->state($STATE_INVALID);
303             }
304         }
305         elsif($state==$STATE_FILE)
306         {
307 #           print "SM: FILE: $name\n";
308             # Can't have anything after a filename
309             $self->state($STATE_INVALID);
310         }
311         elsif($state==$STATE_ALL)
312         {
313             if($name eq $PATH_ALLTRACKS)
314             {
315                 $self->state($STATE_TRACKLIST);
316             }
317             elsif($name eq $PATH_NOARTIST)
318             {
319                 $self->state($STATE_TRACKLIST);
320             }
321             else
322             {
323                 my $artist=ID3FS::Path::Node->new($self->{db}, "artist", $name);
324                 if($artist)
325                 {
326                     push(@{$self->{elements}}, $artist);
327                     $self->state($STATE_ALBUMS);
328                 }
329                 else
330                 {
331                     $self->state($STATE_INVALID);
332                 }
333             }
334         }
335         else
336         {
337             print "SM: ERROR: UNKNOWN STATE: $self->{state}\n";
338             $self->state($STATE_INVALID);
339         }
340     }
341
342     # remove trailing boolean
343     my @elements=@{$self->{elements}};
344     while(@elements && $self->is("boolean", $elements[$#elements]))
345     {
346         pop @elements;
347     }
348     # sort elements by precedence
349     @elements=$self->sort_elements(@elements);
350     $self->{tagtree}=$self->elements_to_tree(\@elements);
351     if($self->{tagtree})
352     {
353 #       my ($conditions, @joins)=$self->{tagtree}->to_sql();
354 #       print "CONDITIONS(", scalar(@joins), "): ", $conditions, "\n";
355     }
356 }
357
358 sub state
359 {
360     my($self, $newstate)=@_;
361     if(defined($newstate))
362     {
363         $self->{state}=$newstate;
364         $self->{curtagdepth}++ if($newstate == $STATE_TAG);
365     }
366     return $self->{state};
367 }
368
369 sub elements_to_tree
370 {
371     my($self, $elements)=@_;
372     return undef unless(@$elements);
373     my ($left, $right, $op)=(undef, undef, undef);
374     my $thing=pop @$elements;
375     if($self->is("boolean", $thing))
376     {
377         $right=$self->elements_to_tree($elements);
378         if($thing->{name} ne "NOT")
379         {
380             $left=$self->elements_to_tree($elements);
381         }
382         $thing->left($left);
383         $thing->right($right);
384     }
385     return $thing;
386 }
387
388 # Dijkstra's shunting-yard algorithm
389 sub sort_elements
390 {
391     my ($self, @input)=@_;
392     my @opstack=();
393     my @output=();
394 #    print "INPUT: ", join(', ', map { $_->{name}; } @input), "\n";
395     while(my $thing = shift @input)
396     {
397         if($self->is("tag", $thing))
398         {
399             # Handle tag values by dropping parent
400             if(@input && $self->is("tag", $input[0]))
401             {
402                 $thing=shift @input;
403             }
404             push(@output, $thing);
405         }
406         elsif($self->is("boolean", $thing))
407         {
408             # bool
409             while(@opstack &&
410                   ($priorities{$thing->{name}} <= $priorities{$opstack[$#opstack]->{name}}))
411             {
412                 push(@output, pop(@opstack));
413             }
414             push(@opstack, $thing);
415         }
416     }
417     while(@opstack)
418     {
419         push(@output, pop(@opstack));
420     }
421 #    print "STACK: ", join(', ', map { $_->{name}; } @output), "\n";
422     return @output;
423 }
424
425 sub used_tags
426 {
427     my($self)=@_;
428     return() unless(defined($self->{tagtree}));
429     return($self->{tagtree}->used_tags());
430 }
431
432 sub expecting_values
433 {
434     my($self)=@_;
435     my $tail=$self->tail();
436     if($self->is("tag", $tail))
437     {
438         return($self->{db}->tag_has_values($tail->id()));
439     }
440 }
441
442 sub trailing_tag_id
443 {
444     my($self)=@_;
445     my $tail=$self->tail();
446     if($self->is("tag", $tail))
447     {
448         return($tail->id());
449     }
450     return undef;
451 }
452
453 sub trailing_tag_parent
454 {
455     my($self)=@_;
456     my $tail=$self->tail();
457     if($self->is("tag", $tail))
458     {
459         return($tail->{parents_id});
460     }
461     return undef;
462 }
463
464 sub tail
465 {
466     my($self)=@_;
467     return($self->{elements}->[$#{$self->{elements}}]);
468 }
469
470 sub at
471 {
472     my($self, $type)=@_;
473     return($self->is($type, $self->tail()));
474 }
475
476 sub is
477 {
478     my($self, $type, $thing)=@_;
479     return 0 unless($thing);
480     return 0 unless($thing->type());
481     return 1 if($type eq $thing->type());
482     return 0;
483 }
484
485 # the one before last
486 sub tail_parent
487 {
488     my($self)=@_;
489     return($self->{elements}->[($#{$self->{elements}}) - 1]);
490 }
491
492 ######################################################################
493
494 sub tags
495 {
496     my($self)=@_;
497     if(!$self->{tagtree}) # / or /NOT
498     {
499         my $sql="SELECT DISTINCT name FROM tags WHERE parents_id='';";
500         return($self->{db}->cmd_firstcol($sql));
501     }
502     my $hasvals=$self->expecting_values();
503     my $parent=$self->trailing_tag_parent();
504 #    print "THASVALS: $hasvals\n";
505 #    print "TPARENT: ", (defined($parent)? $parent : "NO"), "\n";
506     my @ids=();
507     my $sql=("SELECT tags.name FROM (\n" .
508              $self->tags_subselect() .
509              ") AS subselect\n" .
510              "INNER JOIN files_x_tags ON subselect.files_id=files_x_tags.files_id\n" .
511              "INNER JOIN tags ON files_x_tags.tags_id=tags.id\n");
512     my @andclauses=();
513     my $id=$self->trailing_tag_id();
514
515     my $parentclause= "tags.parents_id='";
516     if($hasvals)
517     {
518         $parentclause .= $id;
519     }
520     elsif($parent)
521     {
522         $parentclause .= $parent;
523     }
524     $parentclause .= "'";
525     push(@andclauses, $parentclause);
526
527     my @used=$self->used_tags();
528     if(@used)
529     {
530         push(@andclauses, "tags.id NOT IN (" . join(', ', @used) . ")");
531     }
532     if(@andclauses)
533     {
534         $sql .= "WHERE " . join(' AND ', @andclauses) . "\n";
535     }
536
537     $sql .= "GROUP BY tags.name;";
538     print "SQL(TAGS): $sql\n" if($self->{verbose});
539     my @tagnames=$self->{db}->cmd_firstcol($sql);
540     print("SUBNAMES: ", join(', ', @tagnames), "\n") if($self->{verbose});
541     return(@tagnames);
542 }
543
544 sub artists
545 {
546     my($self)=@_;
547     if(!@{$self->{elements}}) # /ALL
548     {
549         my $sql="SELECT DISTINCT name FROM artists WHERE name!='';";
550         return($self->{db}->cmd_firstcol($sql));
551     }
552     my @ids=();
553     my $sql=$self->sql_start("artists.name");
554     $sql .= ("INNER JOIN artists ON files.artists_id=artists.id\n" .
555              "WHERE artists.name != ''\n" .
556              "GROUP BY artists.name;");
557     print "SQL(ARTISTS): $sql\n" if($self->{verbose});
558     my @tagnames=$self->{db}->cmd_firstcol($sql);
559     print("ARTISTS: ", join(', ', @tagnames), "\n") if($self->{verbose});
560     return(@tagnames);
561 }
562
563 sub albums
564 {
565     my($self)=@_;
566     my @ids=();
567     my $tail=$self->tail();
568     if($self->is("artist", $tail))
569     {
570         return $self->artist_albums($tail->id());
571     }
572     my $sql=$self->sql_start("albums.name");
573     $sql .= ("INNER JOIN albums ON files.albums_id=albums.id\n" .
574              "WHERE albums.name != ''\n" .
575              "GROUP BY albums.name;");
576     print "SQL(ALBUMS): \n$sql\n" if($self->{verbose});
577     my @names=$self->{db}->cmd_firstcol($sql);
578     print("ALBUMS: ", join(', ', @names), "\n") if($self->{verbose});
579     return(@names);
580 }
581
582 sub artist_albums
583 {
584     my($self, $artist_id)=@_;
585     my $sql=$self->sql_start("albums.name");
586     $sql .= ("INNER JOIN albums ON albums.id=files.albums_id\n" .
587              "INNER JOIN artists ON artists.id=files.artists_id\n" .
588              "WHERE artists.id=? and albums.name <> ''\n" .
589              "GROUP BY albums.name\n");
590     print "ARTIST_ALBUMS SQL: $sql\n" if($self->{verbose});
591     my @albums=$self->{db}->cmd_firstcol($sql, $artist_id);
592     print("ALBUMS: ", join(', ', @albums), "\n") if($self->{verbose});
593     return(@albums);
594 }
595
596 sub artist_tracks
597 {
598     my($self, $artist_id)=@_;
599     my $sql=$self->sql_start("files.name");
600     $sql .= ("INNER JOIN artists ON artists.id=files.artists_id\n" .
601              "INNER JOIN albums  ON albums.id=files.albums_id\n" .
602              "WHERE artists.id=? AND albums.name=''\n" .
603              "GROUP BY files.name\n");
604     print "ARTIST_TRACKS SQL: $sql\n" if($self->{verbose});
605     my @names=$self->{db}->cmd_firstcol($sql, $artist_id);
606     print("ARTISTTRACKS: ", join(', ', @names), "\n") if($self->{verbose});
607     return(@names);
608 }
609
610 sub album_tracks
611 {
612     my($self, $artist_id, $album_id)=@_;
613     my $sql=("SELECT files.name FROM files\n" .
614              "INNER JOIN albums  ON albums.id=files.albums_id\n" .
615              "INNER JOIN artists ON artists.id=files.artists_id\n" .
616              "WHERE artists.id=? AND albums.id=?\n" .
617              "GROUP BY files.name\n");
618     print "ALBUM_TRACKS SQL($artist_id, $album_id): $sql\n" if($self->{verbose});
619     my @names=$self->{db}->cmd_firstcol($sql, $artist_id, $album_id);
620     print("TRACKS: ", join(', ', @names), "\n") if($self->{verbose});
621     return(@names);
622 }
623
624 sub tracks
625 {
626     my($self)=@_;
627     my $tail=$self->tail();
628     if($self->is("artist", $tail))
629     {
630         return $self->artist_tracks($tail->id());
631     }
632     elsif($self->is("album", $tail))
633     {
634         my $artist_id=0;
635         my $artist=$self->tail_parent();
636         if($self->is("artist", $artist))
637         {
638             # should always happen
639             $artist_id=$artist->id();
640         }
641         return $self->album_tracks($artist_id, $tail->id());
642     }
643     my $sql=$self->sql_start("files.name");
644     $sql .= "INNER JOIN artists ON files.artists_id=artists.id\n";
645     if($self->{components}->[$#{$self->{components}}] eq $PATH_NOARTIST)
646     {
647         $sql .= "WHERE artists.name =''\n";
648     }
649     $sql .= "GROUP BY files.name;";
650     print "TRACKS SQL($self->{path}): $sql\n" if($self->{verbose});
651     my @names=$self->{db}->cmd_firstcol($sql);
652     print("TRACKS: ", join(', ', @names), "\n") if($self->{verbose});
653     return(@names);
654 }
655
656 sub filename
657 {
658     my($self, $mountpoint)=@_;
659     my $tail=$self->tail();
660     if($self->is("file", $tail))
661     {
662         my $id=$tail->id();
663         my $sql=("SELECT paths.name, files.name FROM files\n" .
664                  "INNER JOIN paths ON files.paths_id=paths.id\n" .
665                  "WHERE files.id=?\n" .
666                  "GROUP BY paths.name, files.name");
667         print "FILENAME SQL: $sql\n" if($self->{verbose});
668         my ($path, $name)=$self->{db}->cmd_onerow($sql, $id);
669         my $id3fs_path=join('/', map { $_->{name}; }  @{$self->{elements}});
670         return($self->{db}->relativise($path, $name, $mountpoint));
671     }
672     # should never happen
673     return "ERROR";
674 }
675
676 sub tags_subselect
677 {
678     my($self)=@_;
679     my $hasvals=$self->expecting_values();
680     if($self->{in_all})
681     {
682         return "\tSELECT id FROM files AS files_id\n";
683     }
684     my $tree=$self->{tagtree};
685     # FIXME
686     print "UNDEF!!\n" unless($self->{tagtree});
687     my $parent=$self->trailing_tag_parent();
688
689 #    print "ELEMENTS: ", join('/', map { $_->{name}; } @{$self->{elements}}), "\n";
690 #    print "TREE: ", $tree->print(), "\n";
691     my $tag=undef;
692     if($hasvals)
693     {
694         $tag=$self->trailing_tag_id();
695 #       print "Trailing id: $tag\n";
696     }
697     my ($sqlclause, @joins)=(undef, ());
698     ($sqlclause, @joins) = $tree->to_sql($hasvals) if($tree);
699 #    print "SQL(" . scalar(@joins) ."): $sqlclause\n";
700     my $sql="\tSELECT fxt1.files_id FROM tags t1";
701     my @crosses=();
702     my @inners=();
703 #    $joinsneeded++ if($tag);
704     for(my $i=0; $i <= $#joins; $i++)
705     {
706         my $cnt=$i+1;
707         my $join=$joins[$i];
708         my $inner=("\t$join JOIN files_x_tags fxt$cnt ON " .
709                    "t${cnt}.id=fxt${cnt}.tags_id");
710         if($i > 0)
711         {
712             push(@crosses, "CROSS JOIN tags t$cnt");
713             $inner .= " AND fxt1.files_id=fxt${cnt}.files_id";
714         }
715         push(@inners, $inner);
716     }
717     $sql .= ("\n\t" . join(" ", @crosses)) if(@crosses);
718     $sql .= ("\n" . join("\n", @inners)) if(@inners);
719     $sql .= "\n\tWHERE $sqlclause" if($sqlclause);
720 #    if($tag)
721 #    {
722 #       $sql .= " AND t${joinsneeded}.parents_id='$tag'";
723 #    }
724     $sql .= "\n\tGROUP BY fxt1.files_id\n";
725     return $sql;
726 }
727
728 sub sql_start
729 {
730     my($self, $tables)=@_;
731     my $sql="SELECT $tables FROM ";
732     if($self->{in_all})
733     {
734         $sql .= "files\n";
735     }
736     else
737     {
738         $sql .= ("(\n" .
739                  $self->tags_subselect() .
740                  ") AS subselect\n" .
741                  "INNER JOIN files ON subselect.files_id=files.id\n");
742     }
743     return $sql;
744 }
745
746
747 sub constraints_tag_list
748 {
749     my($self, @constraints)=@_;
750     my $lasttag=undef;
751     my @tags=();
752     my @tags_vals=();
753     for my $constraint (@constraints)
754     {
755 #       print ref($constraint), ": ", $constraint->{name}, "\n";
756         if($self->is("tag", $constraint))
757         {
758             if(defined($lasttag))
759             {
760 #               print "TAGVAL\n";
761                 push(@tags_vals, [$lasttag, $constraint->id()]) if defined($constraint->id());
762                 $lasttag=undef;
763             }
764             elsif($self->tag_has_values($constraint->id()))
765             {
766 #               print "HASVALUES\n";
767                 $lasttag=$constraint->id() if defined($constraint->id());
768             }
769             else
770             {
771 #               print "NOVALUES\n";
772                 push(@tags, $constraint->id()) if(defined($constraint->id()));
773             }
774         }
775     }
776     @tags=map{ "\"$_\""; } @tags;
777     @tags_vals=map( { [ map({ "\"$_\""; } @$_ ) ] } @tags_vals);
778     $lasttag="\"$lasttag\"" if defined($lasttag);
779     return(\@tags, \@tags_vals, $lasttag);
780 }
781
782 # we just filter $ALLTRACKS, $NOARTIST and $NOALBUM
783 # filtering tags properly requires up to four levels of recursion
784 # (tag/tagval/AND/NOT) and is too slow
785 sub filter
786 {
787     my($self, @dirs)=@_;
788     my $base=$self->{path};
789     my @outdirs=();
790     for my $dir (@dirs)
791     {
792 #       print "\nFILTER (",$self->state(), "): $base / $dir\n";
793         if($self->empty("$base/$dir"))
794         {
795 #           print "empty: $base / $dir\n";
796         }
797         else
798         {
799 #           print "non-empty, accepting: $base / $dir\n";
800             push(@outdirs, $dir);
801         }
802     }
803     return(@outdirs);
804 }
805
806 sub empty
807 {
808     my($self, $dir)=@_;
809     my $path=ID3FS::Path->new($self->{db}, $dir, $self->{verbose},
810                               ($self->{maxtagdepth} - $self->{curtagdepth}));
811     return 1 unless($path->isvalid());
812     my($subdirs,$subfiles)=$path->dirents();
813     return 0 if(@$subfiles || @$subdirs);
814     return 1;
815 }
816
817 1;