<?php

class SurveyAnswerRDFReader
{	
    protected $model;
    protected $respondentID;
    
    protected $filePath;

    public function __construct($surveyUID,$sessionID,$respondentID)
    {

        // Create empty MemModel
        $factory = new ModelFactory();
        $this->model = $factory->getDefaultModel();
        
        $this->respondentID = $respondentID;
        
        $this->filePath = 'data/sessions/' .  $sessionID . '/survey_'.$surveyUID . '/';
    }

    public function loadAnsers()
    {
        if(file_exists($this->filePath.'questions.rdf'))
        {
            $this->model->load($this->filePath.'/answer_'.$this->respondentID.'.rdf');
            return true;
        }
        else
        {
            return false;
        }
    }

    public function getAnswers()
    {
        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?answered 
            WHERE 	
            {
                    _answer        predicates:answered 		?answered 	
            }';

        $result = $this->model->sparqlQuery($querystring);

        return $result;
    }

    public function getAnswerByQuestionID($questionID)
    {
        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?answered 
            WHERE 	
            {
                    _question	predicates:resource_type	resources:question ;
                                predicates:uid			"'.$questionID.'"	;
                                predicates:answered 		?answered 	
            }';

        $result = $this->model->sparqlQuery($querystring);

        return $result;
    }

    public function getAnswersByRespondent($respondentID)
    {
        $this->tempModel->loadModel($this->model);

        $this->tempModel->load($this->answerPath . '/$answer_' . $respondentID);

        $this->tempModel->visualize();

        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?answered 
            WHERE 	
            {
                    _question	predicates:resource_type	resources:question ;
                                predicates:answered 		?answered 	
            }';

        $result = $this->tempModel->sparqlQuery($querystring);

        $this->tempModel->close();		

        $this->tempModel->visualize();

        return $result;
    }

    public function getAnswerByRespondentAndQuestion($respondentID,$questionID)
    {
        $this->tempModel->loadModel($this->model);

        $this->tempModel->load($this->answerPath . '/$answer_' . $respondentID);

        $this->tempModel->visualize();

        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?answered 
            WHERE 	
            {
                    _question	predicates:resource_type	resources:question ;
                                predicates:uid			"'.$questionID.'"	;
                                predicates:answered 		?answered 	
            }';

        $result = $this->tempModel->sparqlQuery($querystring);

        $this->tempModel->close();		

        $this->tempModel->visualize();

        return $result;
    }
}

?>