sql formatting tweaks
[id3fs.git] / lib / ID3FS / Path.pm
index 9020f44..629c02a 100644 (file)
@@ -1,24 +1,36 @@
+# id3fs - a FUSE-based filesystem for browsing audio metadata
+# Copyright (C) 2010  Ian Beckwith <ianb@erislabs.net>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
 package ID3FS::Path;
 
 use strict;
 use warnings;
-use ID3FS::PathElement::Artist;
-use ID3FS::PathElement::Album;
-use ID3FS::PathElement::Boolean;
-use ID3FS::PathElement::File;
-use ID3FS::PathElement::Tag;
-use ID3FS::PathElement::Tagval;
 use ID3FS::Path::Node;
 
-our ($STATE_INVALID, $STATE_ROOT, $STATE_TAG, $STATE_TAGVAL,
-     $STATE_BOOLEAN, $STATE_ALBUMS, $STATE_TRACKLIST,
-     $STATE_FILE, $STATE_ALL)=(0..8);
+our ($STATE_INVALID, $STATE_ROOT, $STATE_TAG, $STATE_BOOLEAN,
+     $STATE_ALBUMS, $STATE_TRACKLIST, $STATE_FILE, $STATE_ALL)=(0..7);
 
+# operator precedence
 our %priorities=( "OR" => 0, "AND" => 1, "NOT" => 2 );
 
-our $PATH_ALLTRACKS="TRACKS";
-our $PATH_NOARTIST="NOARTIST";
-our $PATH_NOALBUM="NOALBUM";
+our $PATH_ALLTRACKS= "TRACKS";
+our $PATH_NOARTIST = "NOARTIST";
+our $PATH_NOALBUM  = "NOALBUM";
+
+our $ENABLE_FILTER = 1;
 
 sub new
 {
@@ -31,6 +43,8 @@ sub new
     $self->{db}=shift;
     $self->{path}=shift;
     $self->{verbose}=shift;
+    $self->{maxtagdepth}=shift;
+    $self->{curtagdepth}=0;
     $self->{path} =~ s/\/\//\//g; # drop doubled slashes
 
     $self->parse();
@@ -52,8 +66,7 @@ sub isdir
 sub isfile
 {
     my($self)=@_;
-    return 1 if($self->state() == $STATE_FILE);
-    return 0;
+    return($self->state() == $STATE_FILE);
 }
 
 sub isvalid
@@ -67,7 +80,7 @@ sub dest
     my($self, $mountpoint)=@_;
     if($self->state() == $STATE_FILE)
     {
-       return $self->filename($mountpoint, $self);
+       return $self->filename($mountpoint);
     }
     return "ERROR"; #should never happen?
 }
@@ -82,41 +95,40 @@ sub dirents
 #    print "DIRENTS: FILE: $self->{path}\n";
     if($state==$STATE_ALL)
     {
-       @dents=($self->artists(), $PATH_ALLTRACKS, $PATH_NOARTIST);
+       @dents=($self->filter($PATH_ALLTRACKS, $PATH_NOARTIST), $self->artists());
     }
-    elsif($state==$STATE_TAG || $state==$STATE_TAGVAL)
+    elsif($state==$STATE_TAG)
     {
-       my $tag=$self->tail();
-       if($state==$STATE_TAG &&
-          defined($tag) &&
-          ref($tag) eq "ID3FS::PathElement::Tag" &&
-          $self->{db}->tag_has_values($tag->{id}))
+       my $tail=$self->tail();
+       if($self->is($TYPE_TAG, $tail) && $self->{db}->tag_has_values($tail->id()))
        {
            @dents=$self->tags();
        }
        else
        {
-           @dents=($self->artists(), qw(AND OR), $PATH_ALLTRACKS, $PATH_NOARTIST);
+           if($self->{maxtagdepth} && ($self->{curtagdepth} < $self->{maxtagdepth}))
+           {
+               @dents=qw(AND OR);
+           }
+           push(@dents, $self->filter($PATH_ALLTRACKS, $PATH_NOARTIST), $self->artists());
        }
     }
     elsif($state==$STATE_BOOLEAN)
     {
-       @dents=$self->tags();
        my $parent=$self->tail();
-       unless(defined($parent) &&
-              ref($parent) eq "ID3FS::PathElement::Boolean" &&
-              $parent->{name} eq "NOT")
+       unless($self->is($TYPE_BOOL, $parent) && $parent->{name} eq "NOT")
        {
-           push(@dents, "NOT");
+           @dents=("NOT");
        }
+       push(@dents,$self->tags());
     }
     elsif($state==$STATE_ROOT)
     {
-       @dents=($self->tags(), qw(ALL NOT));
+       @dents=(qw(ALL NOT), $self->tags());
     }
     elsif($state==$STATE_ALBUMS)
     {
-       @dents=($self->albums(), $PATH_ALLTRACKS, $PATH_NOALBUM);
+       @dents=$self->filter($PATH_ALLTRACKS, $PATH_NOALBUM, $self->albums());
     }
     elsif($state==$STATE_TRACKLIST)
     {
@@ -124,23 +136,23 @@ sub dirents
     }
     else
     {
-       print "DIRENTS: UNHANDLED STATE: $state\n";
+       print "id3fsd: INTERNAL ERROR: DIRENTS: UNHANDLED STATE: $state\n";
     }
     return(\@dents, \@fents);
 }
 
+# State Machine Of Doom
 sub parse
 {
     my($self)=@_;
+    $self->state($STATE_ROOT);
+    return if($self->{path} eq "/");
     @{$self->{components}}=split(/\//, $self->{path});
     shift @{$self->{components}}; # drop empty field before leading /
 #    print "PATH: $self->{path}\n";
-    $self->state($STATE_ROOT);
-    return if($self->{path} eq "/");
     my @parts=@{$self->{components}};
     my($tag, $tagval);
     $self->{elements}=[];
-    $self->{bare_not}=0;
     $self->{in_all}=0;
     my $root_not=0;
     my $tags_seen=0;
@@ -164,12 +176,12 @@ sub parse
            elsif($name eq "NOT")
            {
                $root_not=1;
-               push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+               push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
                $self->state($STATE_BOOLEAN);
            }
            else
            {
-               $tag=ID3FS::PathElement::Tag->new($self->{db}, $name);
+               $tag=ID3FS::Path::Node->new($self->{db}, $TYPE_TAG, $name);
                if($tag)
                {
                    push(@{$self->{elements}}, $tag);
@@ -182,20 +194,16 @@ sub parse
                }
            }
        }
-       elsif($state==$STATE_TAG || $state==$STATE_TAGVAL)
+       elsif($state==$STATE_TAG)
        {
-#          print "SM: TAG/TAGVAL($state): $name\n";
            my $tag=$self->tail();
-           if($state==$STATE_TAG &&
-              defined($tag) &&
-              ref($tag) eq "ID3FS::PathElement::Tag" &&
-              $self->{db}->tag_has_values($tag->{id}))
+#          print "SM: TAG/TAGVAL($state): $name\n";
+           if($self->is($TYPE_TAG, $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});
+#              print "Parsing: parent: $tag->id()\n";
+               my $tagval=ID3FS::Path::Node->new($self->{db}, $TYPE_TAG, $name, $tag->id());
                if(defined($tagval))
                {
-                   $self->state($STATE_TAGVAL);
                    # stay in tag state
                    push(@{$self->{elements}}, $tagval);
                }
@@ -215,16 +223,16 @@ sub parse
            elsif($name eq "AND")
            {
                $self->state($STATE_BOOLEAN);
-               push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+               push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
            }
            elsif($name eq "OR")
            {
                $self->state($STATE_BOOLEAN);
-               push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+               push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
            }
            else
            {
-               my $artist=ID3FS::PathElement::Artist->new($self->{db}, $name);
+               my $artist=ID3FS::Path::Node->new($self->{db}, $TYPE_ARTIST, $name);
                if($artist)
                {
                    push(@{$self->{elements}}, $artist);
@@ -241,8 +249,7 @@ sub parse
 #          print "SM: BOOLEAN: $name\n";
            my $parent=$self->tail();
            my $allownot=1;
-           if(defined($parent) &&
-              ref($parent) eq "ID3FS::PathElement::Boolean" &&
+           if($self->is($TYPE_BOOL, $parent) &&
               $parent->{name} eq "NOT")
            {
                $allownot=0;
@@ -250,11 +257,11 @@ sub parse
            if($allownot && $name eq "NOT")
            {
                $self->state($STATE_BOOLEAN);
-               push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+               push(@{$self->{elements}}, ID3FS::Path::Node->new($self->{db}, $TYPE_BOOL, $name));
            }
            else
            {
-               my $tag=ID3FS::PathElement::Tag->new($self->{db}, $name);
+               my $tag=ID3FS::Path::Node->new($self->{db}, $TYPE_TAG, $name);
                if($tag)
                {
                    push(@{$self->{elements}}, $tag);
@@ -280,7 +287,7 @@ sub parse
            }
            else
            {
-               my $album=ID3FS::PathElement::Album->new($self->{db}, $name);
+               my $album=ID3FS::Path::Node->new($self->{db}, $TYPE_ALBUM, $name);
                if($album)
                {
                    push(@{$self->{elements}}, $album);
@@ -295,7 +302,7 @@ sub parse
        elsif($state==$STATE_TRACKLIST)
        {
 #          print "SM: TRACKLIST: $name\n";
-           my $track=ID3FS::PathElement::File->new($self->{db}, $name);
+           my $track=ID3FS::Path::Node->new($self->{db}, $TYPE_FILE, $name);
            if($track)
            {
                push(@{$self->{elements}}, $track);
@@ -320,12 +327,11 @@ sub parse
            }
            elsif($name eq $PATH_NOARTIST)
            {
-               # FIXME
                $self->state($STATE_TRACKLIST);
            }
            else
            {
-               my $artist=ID3FS::PathElement::Artist->new($self->{db}, $name);
+               my $artist=ID3FS::Path::Node->new($self->{db}, $TYPE_ARTIST, $name);
                if($artist)
                {
                    push(@{$self->{elements}}, $artist);
@@ -344,59 +350,46 @@ sub parse
        }
     }
 
-    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")
+    # remove trailing boolean
+    while(@elements && $self->is($TYPE_BOOL, $elements[$#elements]))
     {
        pop @elements;
     }
     # sort elements by precedence
     @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
 {
     my($self, $newstate)=@_;
-    $self->{state}=$newstate if(defined($newstate));
+    if(defined($newstate))
+    {
+       $self->{state}=$newstate;
+       $self->{curtagdepth}++ if($newstate == $STATE_TAG);
+    }
     return $self->{state};
 }
 
+# link up precedence-sorted list into a binary tree
 sub elements_to_tree
 {
     my($self, $elements)=@_;
     return undef unless(@$elements);
     my ($left, $right, $op)=(undef, undef, undef);
     my $thing=pop @$elements;
-    if(ref($thing) eq "ID3FS::PathElement::Boolean")
+    if($self->is($TYPE_BOOL, $thing))
     {
-       my $op=$thing;
        $right=$self->elements_to_tree($elements);
-       if($op->{name} ne "NOT")
+       if($thing->{name} ne "NOT")
        {
            $left=$self->elements_to_tree($elements);
        }
-       return ID3FS::Path::Node->new($left, $op, $right);
-    }
-    else
-    {
-       return ID3FS::Path::Node->new($thing);
+       $thing->left($left);
+       $thing->right($right);
     }
+    return $thing;
 }
 
 # Dijkstra's shunting-yard algorithm
@@ -408,18 +401,17 @@ sub sort_elements
 #    print "INPUT: ", join(', ', map { $_->{name}; } @input), "\n";
     while(my $thing = shift @input)
     {
-       if(ref($thing) eq "ID3FS::PathElement::Tag")
+       if($self->is($TYPE_TAG, $thing))
        {
            # Handle tag values by dropping parent
-           if(@input && ref($input[0]) eq "ID3FS::PathElement::Tag")
+           if(@input && $self->is($TYPE_TAG, $input[0]))
            {
                $thing=shift @input;
            }
            push(@output, $thing);
        }
-       elsif(ref($thing) eq "ID3FS::PathElement::Boolean")
+       elsif($self->is($TYPE_BOOL, $thing))
        {
-           # bool
            while(@opstack &&
                  ($priorities{$thing->{name}} <= $priorities{$opstack[$#opstack]->{name}}))
            {
@@ -443,13 +435,13 @@ sub used_tags
     return($self->{tagtree}->used_tags());
 }
 
-sub tag_has_values
+sub expecting_values
 {
     my($self)=@_;
     my $tail=$self->tail();
-    if($tail && ref($tail) eq "ID3FS::PathElement::Tag")
+    if($self->is($TYPE_TAG, $tail))
     {
-       return($self->{db}->tag_has_values($tail->{id}));
+       return($self->{db}->tag_has_values($tail->id()));
     }
 }
 
@@ -457,9 +449,9 @@ sub trailing_tag_id
 {
     my($self)=@_;
     my $tail=$self->tail();
-    if($tail && ref($tail) eq "ID3FS::PathElement::Tag")
+    if($self->is($TYPE_TAG, $tail))
     {
-       return($tail->{id});
+       return($tail->id());
     }
     return undef;
 }
@@ -468,7 +460,7 @@ sub trailing_tag_parent
 {
     my($self)=@_;
     my $tail=$self->tail();
-    if($tail && ref($tail) eq "ID3FS::PathElement::Tag")
+    if($self->is($TYPE_TAG, $tail))
     {
        return($tail->{parents_id});
     }
@@ -481,6 +473,15 @@ sub tail
     return($self->{elements}->[$#{$self->{elements}}]);
 }
 
+sub is
+{
+    my($self, $type, $thing)=@_;
+    return 0 unless($thing);
+    return 0 unless($thing->type());
+    return 1 if($type == $thing->type());
+    return 0;
+}
+
 # the one before last
 sub tail_parent
 {
@@ -493,55 +494,33 @@ sub tail_parent
 sub tags
 {
     my($self)=@_;
-    if(!$self->{tagtree}) # / or /NOT  # FIXME: /ALL too?
+    if(!$self->{tagtree}) # / or /NOT
     {
        my $sql="SELECT DISTINCT name FROM tags WHERE parents_id='';";
        return($self->{db}->cmd_firstcol($sql));
     }
-    my $hasvals=$self->tag_has_values();
+    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)
+    my $sql="SELECT tags.name FROM ";
+    if($self->in_or())
     {
-#      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);
+       $sql .= "files_x_tags\n";
     }
     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] . "'))");
-       }
+       $sql .= ("(\n" .
+                $self->tags_subselect() .
+                ") AS subselect\n" .
+                "INNER JOIN files_x_tags ON subselect.files_id=files_x_tags.files_id\n");
     }
+    $sql .= "INNER JOIN tags ON files_x_tags.tags_id=tags.id\n";
+    my @andclauses=();
+    my $id=$self->trailing_tag_id();
 
-    my $parentclause= "(tags.parents_id='";
+    my $parentclause= "tags.parents_id='";
     if($hasvals)
     {
        $parentclause .= $id;
@@ -550,17 +529,19 @@ sub tags
     {
        $parentclause .= $parent;
     }
-    $parentclause .= "')";
+    $parentclause .= "'";
     push(@andclauses, $parentclause);
 
-    if(@orclauses)
+    my @used=$self->used_tags();
+    if(@used)
     {
-       push(@andclauses, '( ' . join(' OR ', @orclauses) . ' )');
+       push(@andclauses, "tags.id NOT IN (" . join(', ', @used) . ")");
     }
     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);
@@ -568,16 +549,6 @@ sub tags
     return(@tagnames);
 }
 
-sub tag_values
-{
-    my($self, $tagid)=@_;
-    my $sql=("SELECT DISTINCT name FROM tags\n" .
-            "WHERE parents_id=?");
-    my @tags=$self->{db}->cmd_firstcol($sql, $tagid);
-    @tags=map { length($_) ? $_ : "NOVALUE"; } @tags;
-    return @tags;
-}
-
 sub artists
 {
     my($self)=@_;
@@ -587,11 +558,8 @@ sub artists
        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" .
+    my $sql=$self->sql_start("artists.name");
+    $sql .= ("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});
@@ -605,27 +573,14 @@ 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})
+    if($self->is($TYPE_ARTIST, $tail))
     {
-       $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;");
+       return $self->artist_albums($tail->id());
     }
+    my $sql=$self->sql_start("albums.name");
+    $sql .= ("INNER JOIN albums ON files.albums_id=albums.id\n" .
+            "WHERE albums.name != ''\n" .
+            "GROUP BY albums.name;");
     print "SQL(ALBUMS): \n$sql\n" if($self->{verbose});
     my @names=$self->{db}->cmd_firstcol($sql);
     print("ALBUMS: ", join(', ', @names), "\n") if($self->{verbose});
@@ -635,18 +590,7 @@ sub albums
 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");
-    }
+    my $sql=$self->sql_start("albums.name");
     $sql .= ("INNER JOIN albums ON albums.id=files.albums_id\n" .
             "INNER JOIN artists ON artists.id=files.artists_id\n" .
             "WHERE artists.id=? and albums.name <> ''\n" .
@@ -660,18 +604,7 @@ sub artist_albums
 sub artist_tracks
 {
     my($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");
-    }
+    my $sql=$self->sql_start("files.name");
     $sql .= ("INNER JOIN artists ON artists.id=files.artists_id\n" .
             "INNER JOIN albums  ON albums.id=files.albums_id\n" .
             "WHERE artists.id=? AND albums.name=''\n" .
@@ -699,35 +632,23 @@ sub album_tracks
 sub tracks
 {
     my($self)=@_;
-    # FIXME: rework PathElements
     my $tail=$self->tail();
-    if(ref($tail) eq "ID3FS::PathElement::Artist")
+    if($self->is($TYPE_ARTIST, $tail))
     {
-       return $self->artist_tracks($tail->{id});
+       return $self->artist_tracks($tail->id());
     }
-    elsif(ref($tail) eq "ID3FS::PathElement::Album")
+    elsif($self->is($TYPE_ALBUM, $tail))
     {
        my $artist_id=0;
        my $artist=$self->tail_parent();
-       if(defined($artist) && (ref($artist) eq "ID3FS::PathElement::Artist"))
+       if($self->is($TYPE_ARTIST, $artist))
        {
            # should always happen
-           $artist_id=$artist->{id};
+           $artist_id=$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");
+       return $self->album_tracks($artist_id, $tail->id());
     }
+    my $sql=$self->sql_start("files.name");
     $sql .= "INNER JOIN artists ON files.artists_id=artists.id\n";
     if($self->{components}->[$#{$self->{components}}] eq $PATH_NOARTIST)
     {
@@ -744,40 +665,28 @@ sub filename
 {
     my($self, $mountpoint)=@_;
     my $tail=$self->tail();
-    if(ref($tail) eq "ID3FS::PathElement::File")
+    if($self->is($TYPE_FILE, $tail))
     {
-       my $id=$tail->{id};
+       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, $id3fs_path));
+       return($self->{db}->relativise($path, $name, $mountpoint, $self->{path}));
     }
-    die("DB::filename: unhandled case\n"); #FIXME
+    # should never happen
+    return "ERROR";
 }
 
 sub tags_subselect
 {
     my($self)=@_;
-    my $hasvals=$self->tag_has_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 $hasvals=$self->expecting_values();
     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)
     {
@@ -786,7 +695,9 @@ sub tags_subselect
     }
     my ($sqlclause, @joins)=(undef, ());
     ($sqlclause, @joins) = $tree->to_sql($hasvals) if($tree);
-#    print "SQL(" . scalar(@joins) .": $sqlclause\n";
+#    use Data::Dumper;
+#    print Dumper $tree if($tree);
+#    print "SQL(" . scalar(@joins) ."): $sqlclause\n";
     my $sql="\tSELECT fxt1.files_id FROM tags t1";
     my @crosses=();
     my @inners=();
@@ -815,275 +726,64 @@ sub tags_subselect
     return $sql;
 }
 
-sub bare_not_subselect
+sub sql_start
 {
-    my($self)=@_;
-    my @tags=grep { ref($_) eq "ID3FS::PathElement::Tag"; } @{$self->{elements}};
-    my $sql=("\tSELECT f1.id AS files_id FROM files f1 WHERE f1.id NOT IN (\n" .
-            "\t\tSELECT fxt1.files_id FROM tags t1\n" .
-            "\t\tINNER JOIN files_x_tags fxt1 ON t1.id=fxt1.tags_id\n" .
-            "\t\tWHERE ");
-    if(scalar(@tags) > 1)
+    my($self, $tables)=@_;
+    my $sql="SELECT $tables FROM ";
+    if($self->{in_all})
     {
-       $sql .= ("(t1.parents_id='" . $tags[0]->{id} . "' AND t1.id='" .
-                $tags[1]->{id} . "')");
+       $sql .= "files\n";
     }
     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 tags_subselect_and_not
-{
-    my($self,@constraints)=@_;
-    my ($tags, $tags_vals, $parent)=$self->constraints_tag_list(@constraints);
-    my @tags=@$tags;
-    my @tags_vals=@$tags_vals;;
-    my $cnt=1;
-    my @andclauses=();
-    my $sql='';
-    for my $tag (@tags)
-    {
-       if($cnt == 1)
-       {
-           $sql="\tSELECT fxt" . scalar(@tags) . ".files_id FROM files_x_tags fxt1\n";
-           push(@andclauses, "\t\tfxt${cnt}.tags_id=$tag");
-       }
-       else
-       {
-           $sql .= ("\tLEFT JOIN files_x_tags fxt$cnt ON fxt" .
-                ($cnt-1) . ".files_id=fxt${cnt}.files_id\n");
-           push(@andclauses, "\t\tfxt${cnt}.tags_id IS NULL");
-       }
-       print "AND: @andclauses\n";
-       $cnt++;
-    }
-    if(@andclauses)
-    {
-       $sql .= "\tWHERE\n\t\t";
-       $sql .= join(" AND\n\t\t", @andclauses) . "\n";
-    }
-    $sql .= "\tGROUP BY fxt". scalar(@tags).".files_id\n";
-    return $sql;
-}
-
-
-sub tags_subselect_and
-{
-    my($self,@constraints)=@_;
-    my ($tags, $tags_vals, $parent)=$self->constraints_tag_list(@constraints);
-    my @tags=@$tags;
-    my @tags_vals=@$tags_vals;;
-    my $cnt=1;
-    my @andclauses=();
-    my $sql='';
-    for my $tag (@tags)
-    {
-       if($cnt == 1)
-       {
-           $sql="\tSELECT fxt" . scalar(@tags) . ".files_id FROM files_x_tags fxt1\n";
-       }
-       else
-       {
-           $sql .= ("\tINNER JOIN files_x_tags fxt$cnt ON fxt" .
-                ($cnt-1) . ".files_id=fxt${cnt}.files_id\n");
-       }
-       push(@andclauses, "\t\tfxt${cnt}.tags_id = $tag");
-       print "AND: @andclauses\n";
-       $cnt++;
-    }
-    if(@andclauses)
-    {
-       $sql .= "\tWHERE\n\t\t";
-       $sql .= join(" AND\n\t\t", @andclauses) . "\n";
-    }
-    $sql .= "\tGROUP BY fxt". scalar(@tags).".files_id\n";
-    return $sql;
-}
-
-sub tags_subselect_or
-{
-    my($self,@constraints)=@_;
-    my ($tags, $tags_vals, $parent)=$self->constraints_tag_list(@constraints);
-    my @tags=@$tags;
-    my @tags_vals=@$tags_vals;;
-
-    my $sql=("\tSELECT files_x_tags.files_id FROM tags t1\n" .
-            "\tINNER JOIN files_x_tags ON t1.id=files_x_tags.tags_id\n");
-    my @orclauses=();
-    my @andclauses=();
-    # FIXME: and / or?
-    if(@tags)
-    {
-       push(@andclauses, "( t1.parents_id=" . (defined($parent) ? $parent : "''") . " )");
-       push(@andclauses, "( t1.id IN ( " . join(', ', @tags) ." ) )");
-    }
-    for my $pair (@tags_vals)
-    {
-       my($tag, $val)=@$pair;
-       push(@orclauses, "( t1.parents_id=$tag AND t1.id=$val )");
-    }
-#    push(@andclauses, "( t1.parents_id=" . (defined($parent) ? $parent : "''") . " )");
-    if(@orclauses)
-    {
-       push(@andclauses, join("\n\t\tOR ", @orclauses));
-    }
-    if(@andclauses)
-    {
-       $sql .= "\tWHERE\n\t\t";
-       $sql .= join("\n\t\tAND ", @andclauses) . "\n";
+       $sql .= ("(\n" .
+                $self->tags_subselect() .
+                ") AS subselect\n" .
+                "INNER JOIN files ON subselect.files_id=files.id\n");
     }
-    $sql .= "\tGROUP BY files_x_tags.files_id\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, $lasttag);
-}
-
-
-sub bare_tags
-{
-    my($self)=@_;
-    my $sql=("SELECT tags.name FROM tags\n" .
-            "WHERE tags.parents_id=''\n" .
-            "GROUP BY tags.name\n");
-    my @names=$self->{db}->cmd_firstcol($sql);
-    return (@names);
-}
-
-sub tags_with_values
-{
-    # FIXME: only shows one level of tag depth
-    my($self)=@_;
-    my $sql=("SELECT p.name, t.name  FROM tags t\n" .
-            "INNER JOIN tags p ON t.parents_id=p.id\n" .
-            "GROUP BY p.name, t.name\n");
-#    print "SQL: $sql\n";
-    my $result=$self->{db}->cmd_rows($sql);
-    my $tags={};
-    for my $pair (@$result)
-    {
-       push(@{$tags->{$pair->[0]}}, $pair->[1]);
-    }
-    return $tags;
-}
-
-
+# we just filter $ALLTRACKS, $NOARTIST and $NOALBUM
+# filtering tags properly requires up to four levels of recursion
+# (tag/tagval/AND/NOT) and is too slow
 sub filter
 {
     my($self, @dirs)=@_;
+    return(@dirs) unless($ENABLE_FILTER);
     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);
-       }
+       push(@outdirs, $dir) unless($self->empty("$base/$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());
+    my($self, $dir)=@_;
+    my $path=ID3FS::Path->new($self->{db}, $dir, $self->{verbose},
+                             ($self->{maxtagdepth} - $self->{curtagdepth}));
     return 1 unless($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", ($maxdepth-1)));
-    }
+    return 0 if(@$subfiles || @$subdirs);
     return 1;
 }
 
-sub tagname_has_values
-{
-    my($self, $name)=@_;
-    my $id=$self->{db}->lookup_id("tags", $name);
-    return 0 unless($id);
-    return $self->{db}->tag_has_values($id);
-
-}
-
-sub dir_is_special
+# if path is .../OR/ or .../OR/NOT
+sub in_or
 {
-    my($self, $dir)=@_;
-    if((grep { $_ eq $dir; }
-       qw(AND OR NOT), $PATH_ALLTRACKS, $PATH_NOARTIST, $PATH_NOALBUM) ||
-       ($self->tagname_has_values($dir)))
-    {
-       return 1;
-    }
+    my($self)=@_;
+    my $tail=$self->tail();
+    return 0 unless($tail);
+    return 0 unless($tail->type() == $TYPE_BOOL);
+    return 1 if($tail->name() eq "OR");
+    return 0 unless($tail->name() eq "NOT");
+    my $parent=$self->tail_parent();
+    return 0 unless($parent);
+    return 0 unless($parent->type() == $TYPE_BOOL);
+    return 1 if($parent->name() eq "OR");
     return 0;
 }