<?php

class ApplicationRDFReader
{
    protected $model;
    protected $fileName;

    public function __construct()
    {
        $this->fileName = 'data/applications/applications.rdf';
    
        $this->reloadApplications();
    }
    
    public function reloadApplications()
    {
        // Create empty MemModel   
        $factory = new ModelFactory();
        $this->model = $factory->getDefaultModel();
        
        if(file_exists($this->fileName))
            $this->model->load($this->fileName);
    }

    public function readApplicationInfo($applicationID)
    {        
        $this->reloadApplications();
        
        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?title ?description ?style
            WHERE 	
            {
                    _application	predicates:resource_type	resources:application ;
                                        predicates:uid			"' . $applicationID . '"	;
                                        predicates:title 		?title 	;
                                        predicates:description		?description	;
                                        predicates:style		?style
            }';

        $result = $this->model->sparqlQuery($querystring);

        return $result;
    }

    public function readAllApplications()
    {
        $result = array();
        $result[] = $this->readApplicationIDs();
        $result[] = $this->readApplicationTitles();				
        $result[] = $this->readApplicationDescriptions();
        $result[] = $this->readApplicationStyles();

        return $result;
    }

    public function readApplicationIDs()
    {
        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?uid
            WHERE 	
            {
                    _application	predicates:resource_type	resources:application ;
                                        predicates:uid			?uid
            }';

        $result = $this->model->sparqlQuery($querystring);

        return $result;
    }

    public function readApplicationTitles()
    {
        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?title
            WHERE 	
            {
                    _application	predicates:resource_type	resources:application ;
                                        predicates:title 		?title 
            }';

        $result = $this->model->sparqlQuery($querystring);

        return $result;
    }

    public function readApplicationDescriptions()
    {
        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?description
            WHERE 	
            {
                    _application	predicates:resource_type	resources:application ;
                                        predicates:description		?description	
            }';

        $result = $this->model->sparqlQuery($querystring);

        return $result;
    }

    public function readApplicationStyles()
    {
        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT  ?style
            WHERE 	
            {
                    _application	predicates:resource_type	resources:application ;
                                        predicates:style		?style
            }';

        $result = $this->model->sparqlQuery($querystring);

        return $result;
    }
}

?>