# 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::Node;

use strict;
use warnings;

require Exporter;
use vars qw(@ISA @EXPORT $TYPE_BOOL $TYPE_TAG $TYPE_ARTIST $TYPE_ALBUM $TYPE_FILE);
@ISA=qw(Exporter);
@EXPORT=qw($TYPE_BOOL $TYPE_TAG $TYPE_ARTIST $TYPE_ALBUM $TYPE_FILE);
($TYPE_BOOL, $TYPE_TAG, $TYPE_ARTIST, $TYPE_ALBUM, $TYPE_FILE)=(1..5);

sub new
{
    my $proto=shift;
    my $class=ref($proto) || $proto;
    my $self={};
    bless($self,$class);

    my $db=shift;
    $self->{type}=shift;
    $self->{name}=shift;
    $self->{parents_id}=shift;
    if($self->{type} != $TYPE_BOOL)
    {
	my $table='';
	if   ($self->{type} == $TYPE_TAG)    { $table="tags";    }
	elsif($self->{type} == $TYPE_ARTIST) { $table="artists"; }
	elsif($self->{type} == $TYPE_ALBUM)  { $table="albums";  }
	elsif($self->{type} == $TYPE_FILE)   { $table="files";   }
	$self->{id}=$db->lookup_id($table, $self->{name}, $self->{parents_id});
	return undef unless(defined($self->{id}));
    }
    return $self;
}

sub set
{
    my($self, $name, $val)=@_;
    if(defined($val))
    {
	$self->{$name}=$val;
    }
    return $self->{$name};
}

sub left       { return shift->set("left",       shift); }
sub right      { return shift->set("right",      shift); }
sub name       { return shift->set("name",       shift); }
sub type       { return shift->set("type",       shift); }
sub id         { return shift->set("id",         shift); }
sub parents_id { return shift->set("parents_id", shift); }

sub to_sql
{
    my($self, $hasvals, $not, @joins)=@_;
    $not=0 unless(defined($not));
    my @outjoins=();
    unless(@joins)
    {
	@outjoins = @joins = ("INNER");
    }
    my $str='';

    if($self->type() != $TYPE_BOOL)
    {
	$str .= "t" . scalar(@joins) . ".id='" . $self->{id} . "'";
	if($not && !$hasvals)
	{
	    $str .= " AND fxt" . scalar(@joins) . ".files_id IS NULL";
	}
	return ($str, @outjoins);
    }

    my $left=$self->left();
    my $right=$self->right();
    return ("", @outjoins) unless($left || $right);
    my ($leftstr, @leftjoins) = $left->to_sql($hasvals, $not, @joins) if($left);
    push(@joins, @leftjoins);
    push(@outjoins, @leftjoins);
    my $op=$self->name();
    print "op: $op type: ", $self->type(), " not: $not\n";
    if(defined($op))
    {
	# if we are ANDing, add an inner join
	# also if we are NOTing, but we are looking for a tag *value*
	if($op eq "AND")
	{
	    print "AND\n";
	    # hack - if right child is a NOT, we don't need extra join/brackets
	    # NOT will do the same and we will end up with an extra one
	    unless($right && $right->name() && $right->name() eq "NOT")
	    {
		push(@joins, "INNER");
		push(@outjoins, "INNER");
	    }
	}
	elsif($op eq "NOT")
	{
	    print "NOT (was $not)\n";
	    $not=1;
	    # as above - if right child is a NOT, we don't need extra join/brackets
	    # NOT will do the same and we will end up with an extra one
	    unless($right && $right->name() && $right->name() eq "NOT")
	    {
		if($hasvals)
		{
		    push(@joins, "INNER");
		    push(@outjoins, "INNER");
		}
		else
		{
		    push(@joins, "LEFT");
		    push(@outjoins, "LEFT");
		}
	    }
	}
	elsif($op eq "OR")
	{
	    print "OR\n";
	    # if left child is a NOT, we need an extra (inner) join
	    # unless right child is also a NOT
	    if(($left && $left->name() && $left->name() eq "NOT") &&
	       !($right && $right->name() && $right->name() eq "NOT"))
	    {
		push(@joins, "INNER");
		push(@outjoins, "INNER");
	    }
	}
    }
    my ($rightstr, @rightjoins) = $right->to_sql($hasvals, $not, @joins) if($right);
    push(@outjoins, @rightjoins);
#    print "LEFT (", scalar(@leftjoins), "): $leftstr\n";
#    print "RIGHT (", scalar(@rightjoins), "): $rightstr\n";
    $str=$leftstr;
    $str .= " $op " if($op && !$not);
    $str .= $rightstr;
    if($op || ($left && $right))
    {
	$str="(" . $str . ")";
    }
#    print "STR: $str\n";
#    my @all=(@joins, @rightjoins);
#    print "JOINS: RETURN ", scalar(@outjoins), " ALL ", scalar(@all), "\n";
    return($str, @outjoins);
}

sub used_tags
{
    my($self)=@_;
    if($self->type() == $TYPE_BOOL)
    {
	my @used=();
	push(@used, $self->left()->used_tags())  if($self->left());
	push(@used, $self->right()->used_tags()) if($self->right());
	return(grep { defined; } @used);
    }
    return $self->id();
}

1;
