sql formatting tweaks
[id3fs.git] / lib / ID3FS / Path.pm
index ee8353d..629c02a 100644 (file)
@@ -1,21 +1,37 @@
+# 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,
-     $STATE_FILE)=(0..7);
+our ($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 $ENABLE_FILTER = 1;
+
 sub new
 {
     my $proto=shift;
@@ -26,6 +42,11 @@ sub new
     $self->{elements}=[];
     $self->{db}=shift;
     $self->{path}=shift;
+    $self->{verbose}=shift;
+    $self->{maxtagdepth}=shift;
+    $self->{curtagdepth}=0;
+    $self->{path} =~ s/\/\//\//g; # drop doubled slashes
+
     $self->parse();
 #    print "STATE: ", $self->state(), "\n";
     return $self;
@@ -45,8 +66,7 @@ sub isdir
 sub isfile
 {
     my($self)=@_;
-    return 1 if($self->state() == $STATE_FILE);
-    return 0;
+    return($self->state() == $STATE_FILE);
 }
 
 sub isvalid
@@ -60,7 +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?
 }
@@ -69,35 +89,38 @@ 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=($self->filter($PATH_ALLTRACKS, $PATH_NOARTIST), $self->artists());
+    }
+    elsif($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=(qw(AND OR TRACKS NOARTIST),
-                   $self->artists());
+           if($self->{maxtagdepth} && ($self->{curtagdepth} < $self->{maxtagdepth}))
+           {
+               @dents=qw(AND OR);
+           }
+           push(@dents, $self->filter($PATH_ALLTRACKS, $PATH_NOARTIST), $self->artists());
        }
     }
     elsif($state==$STATE_BOOLEAN)
     {
        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, $self->tags());
+       push(@dents,$self->tags());
     }
     elsif($state==$STATE_ROOT)
     {
@@ -105,31 +128,35 @@ sub dirents
     }
     elsif($state==$STATE_ALBUMS)
     {
-       @dents=(qw(TRACKS NOALBUM),$self->albums());
+       @dents=$self->filter($PATH_ALLTRACKS, $PATH_NOALBUM, $self->albums());
     }
     elsif($state==$STATE_TRACKLIST)
     {
-       @dents=$self->tracks();
+       @fents=$self->tracks();
     }
     else
     {
-       print "DIRENTS: UNHANDLED STATE: $state\n";
+       print "id3fsd: INTERNAL ERROR: DIRENTS: UNHANDLED STATE: $state\n";
     }
-    return(@dents);
+    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}=[];
-    while(my $name=shift @parts)
+    $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();
@@ -143,19 +170,22 @@ sub parse
 #          print "SM: ROOT: $name\n";
            if($name eq "ALL")
            {
-               $self->state($STATE_TAG);
+               $self->{in_all}=1;
+               $self->state($STATE_ALL);
            }
            elsif($name eq "NOT")
            {
-               push(@{$self->{elements}}, ID3FS::PathElement::Boolean->new($self->{db}, $name));
+               $root_not=1;
+               push(@{$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);
+                   $tags_seen++;
                    $self->state($STATE_TAG);
                }
                else
@@ -164,20 +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);
                }
@@ -186,27 +212,27 @@ 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);
            }
            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);
@@ -223,8 +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")
            {
                $allownot=0;
@@ -232,14 +257,15 @@ sub parse
            if($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);
+                   $tags_seen++;
                    $self->state($STATE_TAG);
                }
                else
@@ -251,17 +277,17 @@ 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);
            }
            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}}, $album);
@@ -276,7 +302,7 @@ sub parse
        elsif($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);
@@ -293,60 +319,77 @@ 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)
+           {
+               $self->state($STATE_TRACKLIST);
+           }
+           else
+           {
+               my $artist=ID3FS::Path::Node->new($self->{db}, $TYPE_ARTIST, $name);
+               if($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);
        }
     }
-    # 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->{andsneeded}) = $self->{tagtree}->to_sql();
-#      print "TREE: ",  $self->{tagtree}->print(), "\n";
-#      print("SQL CONDITION(", $self->{andsneeded}, "): ",
-#            $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
@@ -358,18 +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[$#opstack]->{name}}))
            {
@@ -389,18 +431,17 @@ sub sort_elements
 sub used_tags
 {
     my($self)=@_;
-    print "TAGTREE UNDEF\n" unless(defined($self->{tagtree}));
-    return undef unless(defined($self->{tagtree}));
+    return() unless(defined($self->{tagtree}));
     return($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()));
     }
 }
 
@@ -408,9 +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($tail->id());
     }
     return undef;
 }
@@ -419,7 +460,7 @@ sub trailing_tag_parent
 {
     my($self)=@_;
     my $tail=$self->tail();
-    if($tail && ref($tail) eq "ID3FS::PathElement::Tag")
+    if($self->is($TYPE_TAG, $tail))
     {
        return($tail->{parents_id});
     }
@@ -432,6 +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 == $thing->type());
+    return 0;
+}
+
 # the one before last
 sub tail_parent
 {
@@ -444,55 +494,33 @@ sub tail_parent
 sub tags
 {
     my($self)=@_;
-    if(!@{$self->{elements}}) # /
+    if(!$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;
@@ -501,52 +529,42 @@ 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: $sql\n";
+    print "SQL(TAGS): $sql\n" if($self->{verbose});
     my @tagnames=$self->{db}->cmd_firstcol($sql);
-    print "SUBNAMES: ", join(', ', @tagnames), "\n";
+    print("SUBNAMES: ", join(', ', @tagnames), "\n") if($self->{verbose});
     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)=@_;
     if(!@{$self->{elements}}) # /ALL
     {
-       my $sql="SELECT DISTINCT name FROM artists;";
+       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" .
+    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: $sql\n";
+    print "SQL(ARTISTS): $sql\n" if($self->{verbose});
     my @tagnames=$self->{db}->cmd_firstcol($sql);
-    print "ARTISTS: ", join(', ', @tagnames), "\n";
+    print("ARTISTS: ", join(', ', @tagnames), "\n") if($self->{verbose});
     return(@tagnames);
 }
 
@@ -555,102 +573,91 @@ sub albums
     my($self)=@_;
     my @ids=();
     my $tail=$self->tail();
-    # FIXME: rework PathElements
-    if(ref($tail) eq "ID3FS::PathElement::Artist")
+    if($self->is($TYPE_ARTIST, $tail))
     {
-       return $self->artist_albums($tail->{id});
+       return $self->artist_albums($tail->id());
     }
-    my $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" .
+    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";
+    print "SQL(ALBUMS): \n$sql\n" if($self->{verbose});
     my @names=$self->{db}->cmd_firstcol($sql);
-    print "ALBUMS: ", join(', ', @names), "\n";
+    print("ALBUMS: ", join(', ', @names), "\n") if($self->{verbose});
     return(@names);
 }
 
 sub artist_albums
 {
     my($self, $artist_id)=@_;
-    my $sql=("SELECT albums.name FROM (\n" .
-            $self->tags_subselect() .
-            "\t) AS subselect\n" .
-            "INNER JOIN files ON subselect.files_id=files.id\n" .
-            "INNER JOIN albums ON albums.id=files.albums_id\n\t" .
-            "INNER JOIN artists ON artists.id=files.artists_id\n\t" .
-            "WHERE artists.id=? and albums.name <> ''\n\t" .
+    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" .
             "GROUP BY albums.name\n");
-    print "ARTIST_ALBUMS SQL: $sql\n";
+    print "ARTIST_ALBUMS SQL: $sql\n" if($self->{verbose});
     my @albums=$self->{db}->cmd_firstcol($sql, $artist_id);
-    print "ALBUMS: ", join(', ', @albums), "\n";
+    print("ALBUMS: ", join(', ', @albums), "\n") if($self->{verbose});
     return(@albums);
 }
 
 sub artist_tracks
 {
     my($self, $artist_id)=@_;
-    my $sql=("SELECT files.name FROM (\n" .
-            $self->tags_subselect() .
-            "\t) AS subselect\n" .
-            "INNER JOIN files ON subselect.files_id=files.id\n" .
-            "INNER JOIN artists ON artists.id=files.artists_id\n\t" .
-            "INNER JOIN albums  ON albums.id=files.albums_id\n\t" .
-            "WHERE artists.id=? AND albums.name=''\n\t" .
+    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" .
             "GROUP BY files.name\n");
-    print "ARTIST_TRACKS SQL: $sql\n";
+    print "ARTIST_TRACKS SQL: $sql\n" if($self->{verbose});
     my @names=$self->{db}->cmd_firstcol($sql, $artist_id);
-    print "ARTISTTRACKS: ", join(', ', @names), "\n";
+    print("ARTISTTRACKS: ", join(', ', @names), "\n") if($self->{verbose});
     return(@names);
 }
 
 sub album_tracks
 {
     my($self, $artist_id, $album_id)=@_;
-    my $sql=("SELECT files.name FROM files\n\t" .
-            "INNER JOIN albums  ON albums.id=files.albums_id\n\t" .
-            "INNER JOIN artists ON artists.id=files.artists_id\n\t" .
-            "WHERE artists.id=? AND albums.id=?\n\t" .
+    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): $sql\n";
+    print "ALBUM_TRACKS SQL($artist_id, $album_id): $sql\n" if($self->{verbose});
     my @names=$self->{db}->cmd_firstcol($sql, $artist_id, $album_id);
-    print "TRACKS: ", join(', ', @names), "\n";
+    print("TRACKS: ", join(', ', @names), "\n") if($self->{verbose});
     return(@names);
 }
 
 sub tracks
 {
     my($self)=@_;
-    # FIXME: rework PathElements
     my $tail=$self->tail();
-    if(ref($tail) eq "ID3FS::PathElement::Artist")
+    if($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});
+       return $self->album_tracks($artist_id, $tail->id());
     }
-
-    my $sql=("SELECT files.name\n" .
-            "\tFROM (\n" .
-            $self->tags_subselect() .
-            "\t) AS subselect\n" .
-            "INNER JOIN files ON files.id=subselect.files_id\n" .
-            "GROUP BY files.name;");
-    print "SQL: $sql\n";
+    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)
+    {
+       $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";
+    print("TRACKS: ", join(', ', @names), "\n") if($self->{verbose});
     return(@names);
 }
 
@@ -658,51 +665,53 @@ 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";
+       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->expecting_values();
     my $tree=$self->{tagtree};
-    my $hasvals=$self->tag_has_values();
     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, $joinsneeded)=(undef, 1);
-    ($sqlclause, $joinsneeded) = $tree->to_sql($tag) if($tree);
-#    print "SQL($joinsneeded): $sqlclause\n";
+    my ($sqlclause, @joins)=(undef, ());
+    ($sqlclause, @joins) = $tree->to_sql($hasvals) if($tree);
+#    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=();
 #    $joinsneeded++ if($tag);
-    for(my $i=1; $i <= $joinsneeded; $i++)
+    for(my $i=0; $i <= $#joins; $i++)
     {
-       my $inner=("\tINNER JOIN files_x_tags fxt$i ON " .
-                  "t${i}.id=fxt${i}.tags_id");
-       if($i > 1)
+       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$i");
-           $inner .= " AND fxt1.files_id=fxt${i}.files_id";
+           push(@crosses, "CROSS JOIN tags t$cnt");
+           $inner .= " AND fxt1.files_id=fxt${cnt}.files_id";
        }
        push(@inners, $inner);
     }
@@ -717,181 +726,65 @@ sub tags_subselect
     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 $sql;
-}
-
-
-sub tags_subselect_and
+sub sql_start
 {
-    my($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";
-       $cnt++;
-    }
-    if(@andclauses)
+    my($self, $tables)=@_;
+    my $sql="SELECT $tables FROM ";
+    if($self->{in_all})
     {
-       $sql .= "\tWHERE\n\t\t";
-       $sql .= join(" AND\n\t\t", @andclauses) . "\n";
+       $sql .= "files\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)
+    else
     {
-       $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
+# 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, @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($self->{db}->{postgres})
+    my($self, @dirs)=@_;
+    return(@dirs) unless($ENABLE_FILTER);
+    my $base=$self->{path};
+    my @outdirs=();
+    for my $dir (@dirs)
     {
-       @tags=map{ "\"$_\""; } @tags;
-       @tags_vals=map( { [ map({ "\"$_\""; } @$_ ) ] } @tags_vals);
-       $lasttag="\"$lasttag\"" if defined($lasttag);
+       push(@outdirs, $dir) unless($self->empty("$base/$dir"));
     }
-    return(\@tags, \@tags_vals, $lasttag);
+    return(@outdirs);
 }
 
-
-sub bare_tags
+sub empty
 {
-    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($sql);
-    return (@names);
+    my($self, $dir)=@_;
+    my $path=ID3FS::Path->new($self->{db}, $dir, $self->{verbose},
+                             ($self->{maxtagdepth} - $self->{curtagdepth}));
+    return 1 unless($path->isvalid());
+    my($subdirs,$subfiles)=$path->dirents();
+    return 0 if(@$subfiles || @$subdirs);
+    return 1;
 }
 
-sub tags_with_values
+# if path is .../OR/ or .../OR/NOT
+sub in_or
 {
-    # 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 $tags;
-}
-
-sub lookup_id
-{
-    my($self, $table, $name)=@_;
-    my($id)=$self->{db}->cmd_onerow("SELECT id FROM $table where name=?", $name);
-    return $id;
+    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;
 }
 
 1;