#!/usr/bin/perl

# Probably some pretty major insecurities here because of eval() code.

use RDF::Redland;

WoDo::FACTORY->create_from_json('Person', '
{
	"name" :
	{
		"return" : "first" ,
		"sparql" : "SELECT ?name WHERE { <!> <http://xmlns.com/foaf/0.1/name> ?name . }"
	} ,
	"homepage" :
	{
		"return" : "array" ,
		"sparql" : "SELECT ?homepage WHERE { <!> <http://xmlns.com/foaf/0.1/homepage> ?homepage . }"
	}
}');

my $storage = new RDF::Redland::Storage("hashes", "test", "new='yes',hash-type='memory'");
my $model   = new RDF::Redland::Model($storage, "");
my $parser  = new RDF::Redland::Parser("rdfxml");
my $uri     = new RDF::Redland::URI('http://tobyinkster.co.uk/');
$parser->parse_into_model($uri, $uri, $model);

my $toby = new WoDo::Person('http://tobyinkster.co.uk/#i', $model);
print $toby->name . "\n";

package WoDo::FACTORY;

use JSON;

sub create_from_json
{
	my ($class, $target_class, $json) = @_;
		
	my $klass;
	$klass .= sprintf("package WoDo::\%s;\n", $target_class);
	$klass .= sprintf("\@ISA = qw(WoDo::BASE);\n");
	
	my $methods = from_json($json);
	foreach my $method_name (keys %$methods)
	{
		my $sparql = $methods->{$method_name}->{'sparql'};
		my $return = $methods->{$method_name}->{'return'} || 'objects';
		
		die "Undefined return type: \"return\".\n"
			unless ($return =~ /^(first|array|objects)$/)
			;
		die "Diallowed method name: \"$method_name\".\n"
			if $method_name =~ /[^A-Za-z0-9_]/;
		$sparql =~ s/\'/\\\'/g;
		
		$klass .= "sub $method_name { my (\$self) = \@_; return \$self->_sparql_$return(\'$sparql\'); }\n";
	}
	
	$klass .= "1;\n";

	eval($klass);
	die $@."\n" if $@;
}

1;

package WoDo::BASE;

use RDF::Redland;

sub new
{
	my ($class, $webid, $graph) = @_;
	my $self = {};
	
	$self->{webid} = $webid;
	$self->{graph} = $graph;
	
	bless $self, $class;
}

sub _sparql_first
{
	my ($self, $querystring) = @_;

	$querystring =~ s/<!>/<$self->{webid}>/g;

	my $query = RDF::Redland::Query->new($querystring,
		RDF::Redland::URI->new($self->{webid}),
		undef,
		'sparql');
	
	my $results = $self->{graph}->query_execute($query);
	RESULT: while (! $results->finished)
	{
		my $node = $results->binding_value(0);
		if ($node->type == $RDF::Redland::Node::Type_Resource)
			{ return $node->uri->as_string; }
		elsif ($node->type == $RDF::Redland::Node::Type_Literal)
			{ return $node->literal_value; }
		
		$results->next_result;
	}
	
	return undef;
}

sub _sparql_array
{
	my ($self, $querystring) = @_;

	$querystring =~ s/<!>/<$self->{webid}>/g;

	my $query = RDF::Redland::Query->new($querystring,
		RDF::Redland::URI->new($self->{webid}),
		undef,
		'sparql');
	
	my $rv = [];
	
	my $results = $self->{graph}->query_execute($query);
	RESULT: while (! $results->finished)
	{
		my $node = $results->binding_value(0);
		if ($node->type == $RDF::Redland::Node::Type_Resource)
			{ push @$rv, $node->uri->as_string; }
		elsif ($node->type == $RDF::Redland::Node::Type_Literal)
			{ push @$rv, $node->literal_value; }
		
		$results->next_result;
	}
	
	return $rv;
}

sub _sparql_objects
{
	my ($self, $querystring) = @_;

	$querystring =~ s/<!>/<$self->{webid}>/g;

	my $query = RDF::Redland::Query->new($querystring,
		RDF::Redland::URI->new($self->{webid}),
		undef,
		'sparql');
	
	my $rv = [];
	
	my $results = $self->{graph}->query_execute($query);
	RESULT: while (! $results->finished)
	{
		my $row = {};
		for (my $i=0; $i < $results->bindings_count(); $i++)
		{
			my $name = $results->binding_name($i);
			my $node = $results->binding_value($i);
			
			if ($node->type == $RDF::Redland::Node::Type_Resource)
				{ $row->{$name} = $node->uri->as_string; }
			elsif ($node->type == $RDF::Redland::Node::Type_Literal)
				{ $row->{$name} = $node->literal_value; }
		}
		push @$rv, $row;
	}
	
	return $rv;
}

1;