<?php
class QuestionRDFWriter 
{
    protected $model;

    protected $filePath = 'data/questions/';

    public function __construct()
    {
        // Create empty MemModel
        $factory = new ModelFactory();
        $this->model = $factory->getDefaultModel();

        if (!is_dir($this->filePath))
            mkdir($this->filePath);
        
        if(file_exists($this->filePath.'questions.rdf'))
            $this->model->load($this->filePath.'questions.rdf');
    }	

    public function saveQuestions()
    {	
        $this->model->saveAs($this->filePath.'questions.rdf','rdf');
    }
    
    public function createQuestion($qTitle,$qDescription,$qType,$qCode,$qCategory,$qAnswers)
    {
        $resourceQuestion = new Resource(QUESTION.'/'.$qCode);

        $resourceQuestionType = new Resource(QUESTION);
        $predicateRType = new Resource(RTYPE);
        $this->model->add(new Statement($resourceQuestion,$predicateRType,$resourceQuestionType));

        $predicateTitle = new Resource(TITLE);		
        $questionTitle = new Literal($qTitle);
        $this->model->add(new Statement($resourceQuestion,$predicateTitle,$questionTitle));	

        $predicateDescription = new Resource(DESCRIPTION);
        $questionDescription = new Literal($qDescription);
        $this->model->add(new Statement($resourceQuestion,$predicateDescription,$questionDescription));		

        $predicateQType = new Resource(QTYPE);
        $resourceQuestionType = new Literal($qType);
        $this->model->add(new Statement($resourceQuestion,$predicateQType,$resourceQuestionType));
        
        $predicateQCode = new Resource(QCODE);
        $questionQCode = new Literal($qCode);
        $this->model->add(new Statement($resourceQuestion,$predicateQCode,$questionQCode));
        
        $predicateQCategory = new Resource(QCATEGORY);
        $questionQCategory = new Literal($qCategory);
        $this->model->add(new Statement($resourceQuestion,$predicateQCategory,$questionQCategory));

        foreach($qAnswers as $answer)
        {		
            $answerValue = new Literal($answer);
            $predicateAnswer = new Resource(HAS_ANSWER);	
            $this->model->add(new Statement($resourceQuestion,$predicateAnswer,$answerValue));
        }	
    }
}
?>