<?php
// Survey database interface class as intermediate for storing data from the site to the RDF database 
require_once 'rdfConstants.php';
// Include RAP Library to write RDF files
include(RDFAPI_INCLUDE_DIR . "RDFAPI.php");

/**
 * Description of RespondentConnector
 *
 * @author jkraaijeveld
 */
class RespondentConnector implements IConnector{
    
    protected $model;
    protected $fileName = 'data/users/respondents.rdf';
    
    /**
     * Constructor for RespondentConnector.
     */
    public function __construct()
    {
        //Ensure the required folder for this connector exists
        if (!is_dir('data/users/'))
            mkdir('data/users/');	
    }
    
    /**
     * function load()
     * Loads the file into the standard MemModel.
     */
    public function load() {
        //Get the Memory Model from the ModelFactory
        $this->model = ModelFactory::getDefaultModel();
        
        //Ensure the required file exists before loading
        if(file_exists($this->fileName))
            $this->model->load($this->fileName);
    }
    
    /**
     * function save()
     * Saves the MemModel into the given file.
     */
    public function save() {
        $this->model->saveAs($this->fileName,'rdf'); 
    }
    
    /**
     * function get($arguments)
     * Gets the array of Respondent objects belonging to arguments supplied.
     * @param type $arguments : An array containing zero or more of the following keys:
     *                          'uid', 'name', 'password'
     */
    public function get($arguments) {
        $this->load();
        //Determine which arguments are supplied
        $keys = array_keys($arguments);
        //Set default values for arguments
        $uid = "?uid"; $name = "?name"; $password = "?password";
        //Set the arguments if they are supplied
        if(in_array("uid", $keys))
            $uid = "\"".$arguments["uid"]."\"";
        if(in_array("name", $keys))
            $name = '\''.$arguments["name"].'\'';
        if(in_array("password", $keys))
            $password = "\"".$arguments["password"]."\"";
       
        //Create the querystring 
        $querystring = '
            PREFIX  predicates: <' . SURVEYTOOL_PREDICATES_NAMESPACE . '>
            PREFIX  resources: <' . SURVEYTOOL_RESOURCES_NAMESPACE . '>
            SELECT ?uid, ?name, ?password
            WHERE 	
            {
                    _respondent	predicates:resource_type	resources:respondent ;
					predicates:uid ?uid ;
					predicates:name ?name ;
					predicates:password ?password ;
          			predicates:uid ' . $uid . ' 
					predicates:name ' . $name . ' 
					predicates:password ' . $password . ' 
            }';
        //Query the model
        $results = $this->model->sparqlQuery($querystring);
		$respondents = array();
        if(!empty($results))
        {
            //Run over all results and create appropriate Respondent objets
            foreach($results as $result)
            { 
                    $respondents[] = new Respondent($result['?uid']->label, $result['?name']->label, $result['?password']->label);
            }
        }
        return $respondents;
    }
    
    /**
     * Save the given User object in the file.
     * @param type $rToolObject 
     */
    public function set($rToolObject)
    {
        $this->load();
        $resourceRespondent = new Resource(RESPONDENT . '/' . $rToolObject->uid);
        //Remove the old value stored with the given id
        $this->model->subtract($this->model->find($resourceRespondent, null, null));

		//Set the new values
        $resourceRespondentType = new Resource(RESPONDENT);
        $predicateRType = new Resource(RTYPE);
        $this->model->add(new Statement($resourceRespondent,$predicateRType,$resourceRespondentType));

        $literalRespondentID = new Literal($rToolObject->uid);
        $predicateUniqueID = new Resource(UID);
        $this->model->add(new Statement($resourceRespondent,$predicateUniqueID,$literalRespondentID));
        
        $literalRespondentName = new Literal($rToolObject->name);
        $predicateName = new Resource(NAME);
        $this->model->add(new Statement($resourceRespondent,$predicateName,$literalRespondentName));			

        $literalPassword = new Literal($rToolObject->password);
        $predicatePassword = new Resource(PASSWORD);
        $this->model->add(new Statement($resourceRespondent,$predicatePassword,$literalPassword));
        $this->save();
    }
}

?>