#!/bin/env perl

print "==== Example 4 - Find all the books with a given title (a string)\n" ;
# There are several ways of doing this - here, we use the simple "triples"
# language to do reverse lookup to find the resource, then "fetch" it.

require Joseki ;
require RDF::Core::Model ;
require RDF::Core::Resource ;

my $DC = 'http://purl.org/dc/elements/1.1/' ;
my $dcTitle = $DC.'title' ;

my $kbURL = 'http://jena.hpl.hp.com:2020/books' ;
if ( $#ARGV != -1 )
{
    $kbURL = shift ;
    print "Data source = $kbURL\n" ;
}

my $book = 'http://example.org/book/book1' ;
my $bookRef = new RDF::Core::Resource($book) ;

## # Has a vacrd for author
## my $title = 'Harry Potter And The Prisoner Of Azkaban' ;

# Has no author information.
my $title = 'Harry Potter and the Goblet of Fire' ;
my $titleL = new RDF::Core::Literal($title) ;

my $dcTitleR = new RDF::Core::Resource($dcTitle) ;

my $model = Joseki->triples($kbURL, undef, $dcTitleR, $title) ;
# printModelStmts($model) ;

# What statements did we get?
my $sIter = $model->getStmts(undef, undef, undef) ;

my $statement = $sIter->getFirst; 

for(; defined $statement ; $statement = $sIter->getNext )
{
    print "Book: ",$statement->getSubject->getURI, "\n" ;
    my $m2 = Joseki->fetch($kbURL, $statement->getSubject) ;
    printModelStmts($m2) ;
}

$sIter->close;

sub printModelStmts
{
    my($model) = @_ ;
    my $sIter = $model->getStmts;
    my $stmt = $sIter->getFirst; 
    for(; defined $stmt ; $stmt = $sIter->getNext )
    {
	print "[ ",$stmt->getSubject->getURI,
              ",\n      ",$stmt->getPredicate->getURI,
              ",\n      ",$stmt->getObject->getLabel," ]\n" ;
	
    }
    $sIter->close ;
}