X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2FID3FS%2FPath.pm;h=012cba6d19d9a60cec82c8b7d94f66b457ca26bd;hb=4ed458e770bcb52bf90b05844f2a0c5a9713ee6f;hp=8e7c791f07b113487fb165ebf922c86e88483e76;hpb=87fbf95a66bc4fd0134966a269fbc3ea639b8e34;p=id3fs.git

diff --git a/lib/ID3FS/Path.pm b/lib/ID3FS/Path.pm
index 8e7c791..012cba6 100644
--- a/lib/ID3FS/Path.pm
+++ b/lib/ID3FS/Path.pm
@@ -12,10 +12,14 @@ use ID3FS::Path::Node;
 
 our ($STATE_INVALID, $STATE_ROOT, $STATE_TAG, $STATE_TAGVAL,
      $STATE_BOOLEAN, $STATE_ALBUMS, $STATE_TRACKLIST,
-     $STATE_FILE)=(0..7);
+     $STATE_FILE, $STATE_ALL)=(0..8);
 
 our %priorities=( "OR" => 0, "AND" => 1, "NOT" => 2 );
 
+our $PATH_ALLTRACKS="TRACKS";
+our $PATH_NOARTIST="NOARTIST";
+our $PATH_NOALBUM="NOALBUM";
+
 sub new
 {
     my $proto=shift;
@@ -23,8 +27,12 @@ sub new
     my $self={};
     bless($self,$class);
 
+    $self->{elements}=[];
     $self->{db}=shift;
     $self->{path}=shift;
+    $self->{verbose}=shift;
+    $self->{path} =~ s/\/\//\//g; # drop doubled slashes
+
     $self->parse();
 #    print "STATE: ", $self->state(), "\n";
     return $self;
@@ -59,7 +67,7 @@ sub dest
     my($self, $mountpoint)=@_;
     if($self->state() == $STATE_FILE)
     {
-	return $self->{db}->filename($mountpoint, @{$self->{elements}});
+	return $self->filename($mountpoint, $self);
     }
     return "ERROR"; #should never happen?
 }
@@ -68,53 +76,57 @@ sub dirents
 {
     my($self)=@_;
     my @dents=();
+    my @fents=();
     my $state=$self->state();
 #    print "DIRENTS: STATE: $state\n";
 #    print "DIRENTS: FILE: $self->{path}\n";
-    if($state==$STATE_TAG || $state==$STATE_TAGVAL)
+    if($state==$STATE_ALL)
+    {
+	@dents=($self->artists(), $PATH_ALLTRACKS, $PATH_NOARTIST);
+    }
+    elsif($state==$STATE_TAG || $state==$STATE_TAGVAL)
     {
-	my $tag=$self->{elements}->[$#{$self->{elements}}];
+	my $tag=$self->tail();
 	if($state==$STATE_TAG &&
 	   defined($tag) &&
 	   ref($tag) eq "ID3FS::PathElement::Tag" &&
 	   $self->{db}->tag_has_values($tag->{id}))
 	{
-	    @dents=$self->{db}->tags(@{$self->{elements}});
+	    @dents=$self->tags();
 	}
 	else
 	{
-	    @dents=(qw(AND OR TRACKS NOARTIST),
-		    $self->{db}->artists(@{$self->{elements}}));
+	    @dents=($self->artists(), qw(AND OR), $PATH_ALLTRACKS, $PATH_NOARTIST);
 	}
     }
     elsif($state==$STATE_BOOLEAN)
     {
-	my $parent=$self->{elements}->[$#{$self->{elements}}];
+	@dents=$self->tags();
+	my $parent=$self->tail();
 	unless(defined($parent) &&
 	       ref($parent) eq "ID3FS::PathElement::Boolean" &&
 	       $parent->{name} eq "NOT")
 	{
 	    push(@dents, "NOT");
 	}
-	push(@dents, $self->{db}->tags(@{$self->{elements}}));
     }
     elsif($state==$STATE_ROOT)
     {
-	@dents=(qw(ALL NOT), $self->{db}->tags(@{$self->{elements}}));
+	@dents=($self->tags(), qw(ALL NOT));
     }
     elsif($state==$STATE_ALBUMS)
     {
-	@dents=(qw(TRACKS NOALBUM),$self->{db}->albums(@{$self->{elements}}));
+	@dents=($self->albums(), $PATH_ALLTRACKS, $PATH_NOALBUM);
     }
     elsif($state==$STATE_TRACKLIST)
     {
-	@dents=$self->{db}->tracks(@{$self->{elements}});
+	@fents=$self->tracks();
     }
     else
     {
 	print "DIRENTS: UNHANDLED STATE: $state\n";
     }
-    return(@dents);
+    return(\@dents, \@fents);
 }
 
 sub parse
@@ -128,7 +140,11 @@ sub parse
     my @parts=@{$self->{components}};
     my($tag, $tagval);
     $self->{elements}=[];
-    while(my $name=shift @parts)
+    $self->{bare_not}=0;
+    $self->{in_all}=0;
+    my $root_not=0;
+    my $tags_seen=0;
+    while(defined(my $name=shift @parts))
     {
 #	print "NAME: $name\n";
 	my $state=$self->state();
@@ -142,10 +158,12 @@ sub parse
 #	    print "SM: ROOT: $name\n";
 	    if($name eq "ALL")
 	    {
-		$self->state($STATE_TAG);
+		$self->{in_all}=1;
+		$self->state($STATE_ALL);
 	    }
 	    elsif($name eq "NOT")
 	    {
+		$root_not=1;
 	        push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
 		$self->state($STATE_BOOLEAN);
 	    }
@@ -155,6 +173,7 @@ sub parse
 		if($tag)
 		{
 		    push(@{$self->{elements}}, $tag);
+		    $tags_seen++;
 		    $self->state($STATE_TAG);
 		}
 		else
@@ -166,12 +185,13 @@ sub parse
 	elsif($state==$STATE_TAG || $state==$STATE_TAGVAL)
 	{
 #	    print "SM: TAG/TAGVAL($state): $name\n";
-	    my $tag=$self->{elements}->[$#{$self->{elements}}];
+	    my $tag=$self->tail();
 	    if($state==$STATE_TAG &&
 	       defined($tag) &&
 	       ref($tag) eq "ID3FS::PathElement::Tag" &&
 	       $self->{db}->tag_has_values($tag->{id}))
 	    {
+#		print "Parsing: parent: $tag->{id}\n";
 		my $tagval=ID3FS::PathElement::Tag->new($self->{db}, $name, $tag->{id});
 		if(defined($tagval))
 		{
@@ -184,11 +204,11 @@ sub parse
 		    $self->state($STATE_INVALID);
 		}
 	    }
-	    elsif($name eq "TRACKS")
+	    elsif($name eq $PATH_ALLTRACKS)
 	    {
 		$self->state($STATE_TRACKLIST);
 	    }
-	    elsif($name eq "NOARTIST")
+	    elsif($name eq $PATH_NOARTIST)
 	    {
 		$self->state($STATE_TRACKLIST);
 	    }
@@ -219,7 +239,7 @@ sub parse
 	elsif($state==$STATE_BOOLEAN)
 	{
 #	    print "SM: BOOLEAN: $name\n";
-	    my $parent=$self->{elements}->[$#{$self->{elements}}];
+	    my $parent=$self->tail();
 	    my $allownot=1;
 	    if(defined($parent) &&
 	       ref($parent) eq "ID3FS::PathElement::Boolean" &&
@@ -238,6 +258,7 @@ sub parse
 		if($tag)
 		{
 		    push(@{$self->{elements}}, $tag);
+		    $tags_seen++;
 		    $self->state($STATE_TAG);
 		}
 		else
@@ -249,11 +270,11 @@ sub parse
 	elsif($state==$STATE_ALBUMS)
 	{
 #	    print "SM: ALBUM: $name\n";
-	    if($name eq "TRACKS")
+	    if($name eq $PATH_ALLTRACKS)
 	    {
 		$self->state($STATE_TRACKLIST);
 	    }
-	    elsif($name eq "NOALBUM")
+	    elsif($name eq $PATH_NOALBUM)
 	    {
 		$self->state($STATE_TRACKLIST);
 	    }
@@ -291,17 +312,62 @@ sub parse
 	    # Can't have anything after a filename
 	    $self->state($STATE_INVALID);
 	}
+	elsif($state==$STATE_ALL)
+	{
+	    if($name eq $PATH_ALLTRACKS)
+	    {
+		$self->state($STATE_TRACKLIST);
+	    }
+	    elsif($name eq $PATH_NOARTIST)
+	    {
+		# FIXME
+		$self->state($STATE_TRACKLIST);
+	    }
+	    else
+	    {
+		my $artist=ID3FS::PathElement::Artist->new($self->{db}, $name);
+		if($artist)
+		{
+		    push(@{$self->{elements}}, $artist);
+		    $self->state($STATE_ALBUMS);
+		}
+		else
+		{
+		    $self->state($STATE_INVALID);
+		}
+	    }
+	}
 	else
 	{
 	    print "SM: ERROR: UNKNOWN STATE: $self->{state}\n";
 	    $self->state($STATE_INVALID);
 	}
     }
+
+    if($root_not && ($tags_seen < 2))
+    {
+	$self->{bare_not}=1;
+    }
+
+    # remove trailing boolean
+    my @elements=@{$self->{elements}};
+    while(@elements && ref($elements[$#elements]) eq "ID3FS::PathElement::Boolean")
+    {
+	pop @elements;
+    }
     # sort elements by precedence
-    @{$self->{elements}}=$self->sort_elements(@{$self->{elements}});
-    my $thing=$self->elements_to_tree([ @{$self->{elements}} ]);
-    $self->{tagtree}=$self->elements_to_tree([ @{$self->{elements}} ]);
-#    print($self->{tagtree}->print(), "\n") if $self->{tagtree};
+    @elements=$self->sort_elements(@elements);
+    $self->{tagtree}=$self->elements_to_tree(\@elements);
+    if($self->{tagtree})
+    {
+	($self->{sqlconditions},
+	 $self->{joins}) = $self->{tagtree}->to_sql();
+#	print "TREE: ",  $self->{tagtree}->print(), "\n";
+#	print("SQL CONDITION(", scalar(@{$self->{joins}}), "): ",
+#	      $self->{sqlconditions}, "\n");
+#	use Data::Dumper;
+#	print Dumper $self->{tagtree};
+    }
 }
 
 sub state
@@ -344,33 +410,22 @@ sub sort_elements
     {
 	if(ref($thing) eq "ID3FS::PathElement::Tag")
 	{
-#	    print "Pushing $thing->{name} to output\n";
+	    # Handle tag values by dropping parent
+	    if(@input && ref($input[0]) eq "ID3FS::PathElement::Tag")
+	    {
+		$thing=shift @input;
+	    }
 	    push(@output, $thing);
-#	    print "OPSTACK: ", join(', ', map { $_->{name}; } @opstack), "\n";
-#	    print "OUTPUT: ", join(', ', map { $_->{name}; } @output), "\n";
 	}
 	elsif(ref($thing) eq "ID3FS::PathElement::Boolean")
 	{
-#	    print "BOOL: $thing->{name}\n";
 	    # bool
-#	    print "thing: $thing->{name}: $priorities{$thing->{name}} ";
-	    if(@opstack)
-	    {
-#		print("topop: ", $opstack[$#opstack]->{name},
-#		      ": ", $priorities{$opstack[$#opstack]->{name}}, "\n");
-	    }
 	    while(@opstack &&
 		  ($priorities{$thing->{name}} <= $priorities{$opstack[$#opstack]->{name}}))
 	    {
-#		print "Pushing ", $opstack[$#opstack]->{name}, " from opstack to output\n";
 		push(@output, pop(@opstack));
-#		print "OPSTACK: ", join(', ', map { $_->{name}; } @opstack), "\n";
-#		print "OUTPUT: ", join(', ', map { $_->{name}; } @output), "\n";
 	    }
-#	    print "Pushing $thing->{name} to opstack\n";
 	    push(@opstack, $thing);
-#	    print "OPSTACK: ", join(', ', map { $_->{name}; } @opstack), "\n";
-#	    print "OUTPUT: ", join(', ', map { $_->{name}; } @output), "\n";
 	}
     }
     while(@opstack)
@@ -381,4 +436,504 @@ sub sort_elements
     return @output;
 }
 
+sub used_tags
+{
+    my($self)=@_;
+    return() unless(defined($self->{tagtree}));
+    return($self->{tagtree}->used_tags());
+}
+
+sub expecting_values
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    if($tail && ref($tail) eq "ID3FS::PathElement::Tag")
+    {
+	return($self->{db}->tag_has_values($tail->{id}));
+    }
+}
+
+sub trailing_tag_id
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    if($tail && ref($tail) eq "ID3FS::PathElement::Tag")
+    {
+	return($tail->{id});
+    }
+    return undef;
+}
+
+sub trailing_tag_parent
+{
+    my($self)=@_;
+    my $tail=$self->tail();
+    if($tail && ref($tail) eq "ID3FS::PathElement::Tag")
+    {
+	return($tail->{parents_id});
+    }
+    return undef;
+}
+
+sub tail
+{
+    my($self)=@_;
+    return($self->{elements}->[$#{$self->{elements}}]);
+}
+
+# the one before last
+sub tail_parent
+{
+    my($self)=@_;
+    return($self->{elements}->[($#{$self->{elements}}) - 1]);
+}
+
+######################################################################
+
+sub tags
+{
+    my($self)=@_;
+    if(!$self->{tagtree}) # / or /NOT  # FIXME: /ALL too?
+    {
+	my $sql="SELECT DISTINCT name FROM tags WHERE parents_id='';";
+	return($self->{db}->cmd_firstcol($sql));
+    }
+    my $hasvals=$self->expecting_values();
+    my $parent=$self->trailing_tag_parent();
+#    print "THASVALS: $hasvals\n";
+#    print "TPARENT: ", (defined($parent)? $parent : "NO"), "\n";
+    my @ids=();
+    my $sql=("SELECT tags.name FROM (\n" .
+	     $self->tags_subselect() .
+	     ") AS subselect\n" .
+	     "INNER JOIN files_x_tags ON subselect.files_id=files_x_tags.files_id\n" .
+	     "INNER JOIN tags ON files_x_tags.tags_id=tags.id\n");
+    my @allused=$self->used_tags();
+    my @used=grep { ref($_) ne "ARRAY"; } @allused;
+    my @used_with_vals=grep { ref($_) eq "ARRAY"; } @allused;
+#    print "tags(): USED: ", join(", ", @used), "\n";
+#    print "tags(): USED_WITH_VALS: ", join(", ", map { "[".$_->[0]. ", ".$_->[1]."]";} @used_with_vals), "\n";
+    my @orclauses=();
+    my @andclauses=();
+    my $id=$self->trailing_tag_id();
+    if($hasvals)
+    {
+#	print "HAS_VALUES\n";
+	my @values=map { "'".$_->[1]."'"; } grep { $_->[0] == $id; } @used_with_vals;
+	my $clause="(tags.parents_id='$id'";
+	if(@values)
+	{
+	    $clause .= " AND tags.id NOT IN (" . join(', ', @values) . ")";
+	}
+	$clause .= ")";
+	push(@andclauses, $clause);
+    }
+    else
+    {
+#	print "HASNT VALUES\n";;
+	if(@used)
+	{
+	    push(@andclauses, "(NOT (tags.parents_id='' AND tags.id IN (" . join(', ', @used) . ")))");
+	}
+	for my $pair (@used_with_vals)
+	{
+	    push(@andclauses, "(NOT (tags.parents_id='" . $pair->[0] . "' AND tags.id='" . $pair->[1] . "'))");
+	}
+    }
+
+    my $parentclause= "(tags.parents_id='";
+    if($hasvals)
+    {
+	$parentclause .= $id;
+    }
+    elsif($parent)
+    {
+	$parentclause .= $parent;
+    }
+    $parentclause .= "')";
+    push(@andclauses, $parentclause);
+
+    if(@orclauses)
+    {
+	push(@andclauses, '( ' . join(' OR ', @orclauses) . ' )');
+    }
+    if(@andclauses)
+    {
+	$sql .= "WHERE " . join(' AND ', @andclauses) . "\n";
+    }
+    $sql .= "GROUP BY tags.name;";
+    print "SQL(TAGS): $sql\n" if($self->{verbose});
+    my @tagnames=$self->{db}->cmd_firstcol($sql);
+    print("SUBNAMES: ", join(', ', @tagnames), "\n") if($self->{verbose});
+    return(@tagnames);
+}
+
+sub artists
+{
+    my($self)=@_;
+    if(!@{$self->{elements}}) # /ALL
+    {
+	my $sql="SELECT DISTINCT name FROM artists WHERE name!='';";
+	return($self->{db}->cmd_firstcol($sql));
+    }
+    my @ids=();
+    my $sql=("SELECT artists.name FROM (\n" .
+	     $self->tags_subselect() .
+	     ") AS subselect\n" .
+	     "INNER JOIN files ON subselect.files_id=files.id\n" .
+	     "INNER JOIN artists ON files.artists_id=artists.id\n" .
+	     "WHERE artists.name != ''\n" .
+	     "GROUP BY artists.name;");
+    print "SQL(ARTISTS): $sql\n" if($self->{verbose});
+    my @tagnames=$self->{db}->cmd_firstcol($sql);
+    print("ARTISTS: ", join(', ', @tagnames), "\n") if($self->{verbose});
+    return(@tagnames);
+}
+
+sub albums
+{
+    my($self)=@_;
+    my @ids=();
+    my $tail=$self->tail();
+    # FIXME: rework PathElements
+    if(ref($tail) eq "ID3FS::PathElement::Artist")
+    {
+	return $self->artist_albums($tail->{id});
+    }
+    my $sql;
+    if($self->{in_all})
+    {
+	$sql="SELECT name FROM albums";
+    }
+    else
+    {
+	$sql=("SELECT albums.name\n" .
+	      "\tFROM (\n" .
+	      $self->tags_subselect() .
+	      "\t) AS subselect\n" .
+	      "INNER JOIN files ON subselect.files_id=files.id\n" .
+	      "INNER JOIN albums ON files.albums_id=albums.id\n" .
+	      "WHERE albums.name != ''\n" .
+	      "GROUP BY albums.name;");
+    }
+    print "SQL(ALBUMS): \n$sql\n" if($self->{verbose});
+    my @names=$self->{db}->cmd_firstcol($sql);
+    print("ALBUMS: ", join(', ', @names), "\n") if($self->{verbose});
+    return(@names);
+}
+
+sub artist_albums
+{
+    my($self, $artist_id)=@_;
+    my $sql="SELECT albums.name FROM ";
+    if($self->{in_all})
+    {
+	$sql .= "files\n";
+    }
+    else
+    {
+	$sql .= ("(\n" .
+		 $self->tags_subselect() .
+		 ") AS subselect\n" .
+		 "INNER JOIN files ON subselect.files_id=files.id\n");
+    }
+    $sql .= ("INNER JOIN albums ON albums.id=files.albums_id\n" .
+	     "INNER JOIN artists ON artists.id=files.artists_id\n" .
+	     "WHERE artists.id=? and albums.name <> ''\n" .
+	     "GROUP BY albums.name\n");
+    print "ARTIST_ALBUMS SQL: $sql\n" if($self->{verbose});
+    my @albums=$self->{db}->cmd_firstcol($sql, $artist_id);
+    print("ALBUMS: ", join(', ', @albums), "\n") if($self->{verbose});
+    return(@albums);
+}
+
+sub artist_tracks
+{
+    my($self, $artist_id)=@_;
+    my $sql="SELECT files.name FROM ";
+    if($self->{in_all})
+    {
+	$sql .= "files\n";
+    }
+    else
+    {
+	$sql .= ("(\n" .
+		 $self->tags_subselect() .
+		 "\t) AS subselect\n" .
+		 "INNER JOIN files ON subselect.files_id=files.id\n");
+    }
+    $sql .= ("INNER JOIN artists ON artists.id=files.artists_id\n" .
+	     "INNER JOIN albums  ON albums.id=files.albums_id\n" .
+	     "WHERE artists.id=? AND albums.name=''\n" .
+	     "GROUP BY files.name\n");
+    print "ARTIST_TRACKS SQL: $sql\n" if($self->{verbose});
+    my @names=$self->{db}->cmd_firstcol($sql, $artist_id);
+    print("ARTISTTRACKS: ", join(', ', @names), "\n") if($self->{verbose});
+    return(@names);
+}
+
+sub album_tracks
+{
+    my($self, $artist_id, $album_id)=@_;
+    my $sql=("SELECT files.name FROM files\n" .
+	     "INNER JOIN albums  ON albums.id=files.albums_id\n" .
+	     "INNER JOIN artists ON artists.id=files.artists_id\n" .
+	     "WHERE artists.id=? AND albums.id=?\n" .
+	     "GROUP BY files.name\n");
+    print "ALBUM_TRACKS SQL($artist_id, $album_id): $sql\n" if($self->{verbose});
+    my @names=$self->{db}->cmd_firstcol($sql, $artist_id, $album_id);
+    print("TRACKS: ", join(', ', @names), "\n") if($self->{verbose});
+    return(@names);
+}
+
+sub tracks
+{
+    my($self)=@_;
+    # FIXME: rework PathElements
+    my $tail=$self->tail();
+    if(ref($tail) eq "ID3FS::PathElement::Artist")
+    {
+	return $self->artist_tracks($tail->{id});
+    }
+    elsif(ref($tail) eq "ID3FS::PathElement::Album")
+    {
+	my $artist_id=0;
+	my $artist=$self->tail_parent();
+	if(defined($artist) && (ref($artist) eq "ID3FS::PathElement::Artist"))
+	{
+	    # should always happen
+	    $artist_id=$artist->{id};
+	}
+	return $self->album_tracks($artist_id, $tail->{id});
+    }
+    my $sql="SELECT files.name FROM ";
+    if($self->{in_all})
+    {
+	$sql .= "files\n";
+    }
+    else
+    {
+	$sql .= ("(\n" .
+		 $self->tags_subselect() .
+		 ") AS subselect\n" .
+		 "INNER JOIN files ON files.id=subselect.files_id\n");
+    }
+    $sql .= "INNER JOIN artists ON files.artists_id=artists.id\n";
+    if($self->{components}->[$#{$self->{components}}] eq $PATH_NOARTIST)
+    {
+	$sql .= "WHERE artists.name =''\n";
+    }
+    $sql .= "GROUP BY files.name;";
+    print "TRACKS SQL($self->{path}): $sql\n" if($self->{verbose});
+    my @names=$self->{db}->cmd_firstcol($sql);
+    print("TRACKS: ", join(', ', @names), "\n") if($self->{verbose});
+    return(@names);
+}
+
+sub filename
+{
+    my($self, $mountpoint)=@_;
+    my $tail=$self->tail();
+    if(ref($tail) eq "ID3FS::PathElement::File")
+    {
+	my $id=$tail->{id};
+	my $sql=("SELECT paths.name, files.name FROM files\n" .
+		 "INNER JOIN paths ON files.paths_id=paths.id\n" .
+		 "WHERE files.id=?\n" .
+		 "GROUP BY paths.name, files.name");
+	print "FILENAME SQL: $sql\n" if($self->{verbose});
+	my ($path, $name)=$self->{db}->cmd_onerow($sql, $id);
+	my $id3fs_path=join('/', map { $_->{name}; }  @{$self->{elements}});
+	return($self->{db}->relativise($path, $name, $mountpoint, $id3fs_path));
+    }
+    die("DB::filename: unhandled case\n"); #FIXME
+}
+
+sub tags_subselect
+{
+    my($self)=@_;
+    my $hasvals=$self->expecting_values();
+    # we need to specially handle a bare /NOT/tag with no other clauses,
+    # using a simple WHERE id !='tagid' instead of a LEFT JOIN
+    if($self->{bare_not})
+    {
+	return $self->bare_not_subselect();
+    }
+    if($self->{in_all})
+    {
+	return "\tSELECT id FROM files AS files_id\n";
+    }
+    my $tree=$self->{tagtree};
+    my $parent=$self->trailing_tag_parent();
+
+#    print "ELEMENTS: ", join('/', map { $_->{name}; } @{$self->{elements}}), "\n";
+#    print "TREE: ", $tree->print(), "\n";
+    my $tag=undef;
+    if($hasvals)
+    {
+	$tag=$self->trailing_tag_id();
+#	print "Trailing id: $tag\n";
+    }
+    my ($sqlclause, @joins)=(undef, ());
+    ($sqlclause, @joins) = $tree->to_sql($hasvals) if($tree);
+#    print "SQL(" . scalar(@joins) .": $sqlclause\n";
+    my $sql="\tSELECT fxt1.files_id FROM tags t1";
+    my @crosses=();
+    my @inners=();
+#    $joinsneeded++ if($tag);
+    for(my $i=0; $i <= $#joins; $i++)
+    {
+	my $cnt=$i+1;
+	my $join=$joins[$i];
+	my $inner=("\t$join JOIN files_x_tags fxt$cnt ON " .
+		   "t${cnt}.id=fxt${cnt}.tags_id");
+	if($i > 0)
+	{
+	    push(@crosses, "CROSS JOIN tags t$cnt");
+	    $inner .= " AND fxt1.files_id=fxt${cnt}.files_id";
+	}
+	push(@inners, $inner);
+    }
+    $sql .= ("\n\t" . join(" ", @crosses)) if(@crosses);
+    $sql .= ("\n" . join("\n", @inners)) if(@inners);
+    $sql .= "\n\tWHERE $sqlclause" if($sqlclause);
+#    if($tag)
+#    {
+#	$sql .= " AND t${joinsneeded}.parents_id='$tag'";
+#    }
+    $sql .= "\n\tGROUP BY fxt1.files_id\n";
+    return $sql;
+}
+
+sub bare_not_subselect
+{
+    my($self)=@_;
+    my @tags=grep { ref($_) eq "ID3FS::PathElement::Tag"; } @{$self->{elements}};
+    my $sql=("\tSELECT f1.id AS files_id FROM files f1 WHERE f1.id NOT IN (\n" .
+	     "\t\tSELECT fxt1.files_id FROM tags t1\n" .
+	     "\t\tINNER JOIN files_x_tags fxt1 ON t1.id=fxt1.tags_id\n" .
+	     "\t\tWHERE ");
+    if(scalar(@tags) > 1)
+    {
+	$sql .= ("(t1.parents_id='" . $tags[0]->{id} . "' AND t1.id='" .
+		 $tags[1]->{id} . "')");
+    }
+    else
+    {
+	$sql .= ("(t1.parents_id='' AND t1.id='" . $tags[0]->{id} . "')");
+    }
+    $sql .= "\n\t\tGROUP BY fxt1.files_id\n\t)\n";
+    return($sql);
+}
+
+sub constraints_tag_list
+{
+    my($self, @constraints)=@_;
+    my $lasttag=undef;
+    my @tags=();
+    my @tags_vals=();
+    for my $constraint (@constraints)
+    {
+#	print ref($constraint), ": ", $constraint->{name}, "\n";
+	if(ref($constraint) eq "ID3FS::PathElement::Tag")
+	{
+	    if(defined($lasttag))
+	    {
+#		print "TAGVAL\n";
+		push(@tags_vals, [$lasttag, $constraint->{id}]) if defined($constraint->{id});
+		$lasttag=undef;
+	    }
+	    elsif($self->tag_has_values($constraint->{id}))
+	    {
+#		print "HASVALUES\n";
+		$lasttag=$constraint->{id} if defined($constraint->{id});
+	    }
+	    else
+	    {
+#		print "NOVALUES\n";
+		push(@tags, $constraint->{id}) if(defined($constraint->{id}));
+	    }
+	}
+    }
+    unless($self->{db}->{postgres})
+    {
+	@tags=map{ "\"$_\""; } @tags;
+	@tags_vals=map( { [ map({ "\"$_\""; } @$_ ) ] } @tags_vals);
+	$lasttag="\"$lasttag\"" if defined($lasttag);
+    }
+    return(\@tags, \@tags_vals, $lasttag);
+}
+
+sub filter
+{
+    my($self, @dirs)=@_;
+    my $base=$self->{path};
+    my @outdirs=();
+    # depth 4 to allow for tag/tagval/AND/NOT
+    my $maxdepth=4;
+    for my $dir (@dirs)
+    {
+#	print "\nFILTER (",$self->state(), "): $base / $dir\n";
+	if($self->empty("$base/$dir", $maxdepth))
+	{
+#	    print "empty: $base / $dir\n";
+	}
+	else
+	{
+#	    print "non-empty, accepting: $base / $dir\n";
+	    push(@outdirs, $dir);
+	}
+    }
+    return(@outdirs);
+}
+
+sub empty
+{
+    my($self, $dir, $maxdepth)=@_;
+    return 0 unless($maxdepth);
+#    print "testing($maxdepth): $dir\n";
+    my $path=ID3FS::Path->new($self->{db}, $dir, $self->{verbose});
+#    print "PATH INVALID\n" unless($path->isvalid());
+    return 1 unless($path->isvalid());
+    my($subdirs,$subfiles)=$path->dirents();
+#    print "SUBDENTS: ", join(", ", @$subdirs, @$subfiles), "\n";
+#    print("SUBFILES: ", join(', ', @$subfiles), "\n") if(@$subfiles);
+    return 0 if(@$subfiles);
+    for my $subdir (@$subdirs)
+    {
+#	print "SUBSUB $dir/$subdir\n";
+	if(1) #$self->dir_is_special($subdir))
+	{
+	    if($self->empty("$dir/$subdir", ($maxdepth-1)))
+	    {
+#		print "EMPTY: $dir / $subdir\n";
+	    }
+	    else
+	    {
+#		print "NONEMPTY: $dir / $subdir\n";
+		return 0;
+	    }
+	}
+	else
+	{
+	    return 0;
+	}
+#	return 0 if($self->nonempty("$dir/$subdir", ($maxdepth-1)));
+    }
+    return 1;
+}
+
+sub dir_is_special
+{
+    my($self, $dir)=@_;
+    my $id=$self->{db}->lookup_id("tags", $dir);
+    if((grep { $_ eq $dir; } (qw(AND OR NOT), $PATH_ALLTRACKS,
+			      $PATH_NOARTIST, $PATH_NOALBUM)) ||
+       ($id && $self->{db}->tag_has_values($id)))
+    {
+	return 1;
+    }
+    return 0;
+}
+
 1;