<?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");



class SurveyCreationDatabaseInterface
{		
    protected $surveyRDFWriter;
    protected $surveyRDFReader;
    protected $questionRDFWriter;
    protected $questionRDFReader;

    public function __construct($surveyID)
    {
        if($surveyID == null)
            $surveyUID = md5( uniqid(rand(), true) );
        else
            $surveyUID = $surveyID;

        $this->surveyRDFWriter = new SurveyRDFWriter($surveyUID);
        $this->surveyRDFReader = new SurveyRDFReader($surveyUID);
        $this->questionRDFWriter = new QuestionRDFWriter();
        $this->questionRDFReader = new QuestionRDFReader();
    }

    public function setSurveyInfo($survey,$user)
    {
        $sTitle = $survey['surveyTitle'];
        $sDescription = $survey['surveyDescription'];

        $this->surveyRDFWriter->createSurvey($sTitle,$sDescription);

        $sUserID = $user['username'];

        $this->surveyRDFWriter->setUserData($sUserID);

        $qNumber = 1;
        while (isset($survey['questionCode'.$qNumber]))
        {
            $qCode = $survey['questionCode'.$qNumber];          
            $this->surveyRDFWriter->addQuestion($qCode);

            $qNumber++;
        }

        $this->surveyRDFWriter->saveSurvey();
        $this->questionRDFWriter->saveQuestions();
    }
    
    public function saveQuestion($questionInfo)
    {
        $qCode = $question['questionCode'.$qNumber];
        $qTitle = $question['questionTitle'.$qNumber];
        $qDescription = $question['questionDescription'.$qNumber];
        $qType = $question['questionType'.$qNumber];

        $qAnswers = array();
        $aNumber = 1;
        while (isset($question['ans'.$aNumber]))
        {
            $qAnswers[] = $question['ans'.$aNumber];

            $aNumber++;
        }
        
        if($this->checkQuestionCodeExists($qCode))
        {
            return 'Question code (' . $qCode . ') already in use. Please try a new code.';
        }
        else 
        {
            $this->questionRDFWriter->createQuestion($qTitle,$qDescription,$qType,$qCode,"null",$qAnswers);
            return 'Question saved';
        }
    }

    public function getSurveyInfo()
    {
        $surveyInfo = array();

        $this->questionRDFReader->loadQuestions();
        
        $resultSurvey = $this->surveyRDFReader->getSurveyInfo();
        
        $surveyInfo['surveyID'] = $resultSurvey['info'][0]['?uid']->label;
        $surveyInfo['surveyTitle'] = $resultSurvey['info'][0]['?title']->label;
        $surveyInfo['surveyDescription'] = $resultSurvey['info'][0]['?description']->label;
        $surveyInfo['surveyCreator'] = $resultSurvey['info'][0]['?creator']->label;
        $surveyQuestionIDs = $resultSurvey['questionIDs'];
        
        if($surveyQuestionIDs != false)
        {
            $qNumber = 1;
            foreach($surveyQuestionIDs as $qID)
            {
                $questionID = $qID['?questionID']->label;
                $surveyInfo['questionID'.$qNumber] = $questionID;

                $questionTitleObject = $this->questionRDFReader->readQuestionTitle($questionID);
                $surveyInfo['questionTitle'.$qNumber] = $questionTitleObject[0]['?questionTitle']->label;

                $questionDescriptionObject = $this->questionRDFReader->readQuestionDescription($questionID);
                $surveyInfo['questionDescription'.$qNumber] = $questionDescriptionObject[0]['?questionDescription']->label;

                $questionTypeObject = $this->questionRDFReader->readQuestionType($questionID);
                $surveyInfo['questionType'.$qNumber] = $questionTypeObject[0]['?questionType']->label;

                $resultAnswers = $this->questionRDFReader->readQuestionAnswers($questionID);

                if ($resultAnswers != null)
                {
                    for($aNumber = 1;$aNumber<=sizeof($resultAnswers);$aNumber++)
                    {
                        $surveyInfo['q'.$qNumber.'ans'.$aNumber] = $resultAnswers[$aNumber-1]['?answerDescription']->label;
                    }
                }
                $resultAnswers = null;
                $qNumber++;
            }
        }
        
        return $surveyInfo;
    }
    
    public function getExistingSurveys()
    {
        $surveyIDs = array();
        $surveys = array();

        if($handle = opendir('data/surveys/'))
        {
            while (false !== ($file = readdir($handle))) {
                if(strstr($file, 'survey_') && strstr($file, '.rdf'))
                    $surveyIDs[] = substr($file,7,strlen($file)-11);
            }
        }
        
        foreach($surveyIDs as $surveyID)
        {
            $surveyTitle = $this->surveyRDFReader->getSurveyTitleByID($surveyID);
            $surveys[$surveyID] = $surveyTitle[0]['?title']->label;
        }

        return $surveys;
    }
    
    public function getExistingQuestions()
    {
        $questions = array();

        $resultQuestions = $this->questionRDFReader->readQuestionCodes();
        foreach ($resultQuestions as $questionCodeObject)
        {
            $questionCode = $questionCodeObject[0]['?questionCode']->label;
            $questionTitle = $this->questionRDFReader->readQuestionTitle($questionCode);
            $questions[$questionCode] = $questionTitle[0]['?questionTitle']->label;
        }

        return $questions;
    }
    
    public function getSurveyTitleByID($surveyID)
    {
        $surveyTitleLiteral = $this->surveyRDFReader->getSurveyTitleByID($surveyID);
        $surveyTitle = $surveyTitle[0]['?title']->label;
        
        return $surveyTitle;
    }
    
    public function checkQuestionCodeExists($qCode)
    {
        $result = false;

        $questionCodes = $this->questionRDFReader->readQuestionCodes();
        
        if ($questionCodes != null)
        {
            foreach($questionCodes as $questionCode)
            {
                $code = $questionCode['?questionCode']->label;
                if(!strcmp($code ,$qCode))
                {
                    $result = true;
                    break;
                }
            }
        }

        return $result;
    }
}
?>