/lenasys/0.1

//// Returns a quiz variant including quiz data (If the student is registered for the course and the quiz is open)

//// If no quiz variant already assigned to the student a variant will be randomly selected and assigned

//// Parameters: (POST) login, courseName, courseOccasion, quizNr

 

session_start();

//Check if the sent login name is the same as the one stored in the session

 

//Prevents browsers (IE) from caching the response

header('Cache-Control: no-cache, must-revalidate');

header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');

//header('Content-type: application/json');

header('Content-type: application/json; charset=utf-8'); 

/* Function used to fetch quiz variant data */

        $queryString=" SELECT QuizVariant.quizNr, QuizVariant.quizCourseName, QuizVariant.quizObjectIDs, Quiz.quizData 

                                        FROM QuizVariant, Quiz

                                        WHERE QuizVariant.quizNr=Quiz.nr 

        return $quizVariantData;

}

 

 

//Check if the student is a praticipant of the course

$queryString="SELECT COUNT(*) 

$stmt->bindParam(':COCCASION', $_POST['courseOccasion']);

$stmt->execute();

 

        

        //Check if quiz is open

        $queryString="SELECT Quiz.opening, Quiz.closing, Quiz.allowMultipleReplies

        $stmt->bindParam(':CNAME', $_POST['courseName']);

        $stmt->execute();

        $quizData=$stmt->fetch(PDO::FETCH_ASSOC); 

                $now = new DateTime();

                $opening = new DateTime($quizData['opening']);

                $closing = new DateTime($quizData['closing']);

        $result=$stmt->fetch(PDO::FETCH_ASSOC);

        if($result){ //If this quiz is assigned to the student

        //if($stmt->rowCount() >= 1){ //If this quiz is assigned to the student

        } else { //This quiz has not been assigned to the student

                //Select random variant for requested quiz nr (for a particular course)

                //$queryString="SELECT COUNT(QuizVariant.quizNr) 

                $queryString="SELECT QuizVariant.qVarNr 

                                          FROM QuizVariant

                                          WHERE QuizVariant.quizNr=:QNR 

                

                $stmt = $pdo->prepare($queryString);

                $stmt->bindParam(':QNR', $_POST['quizNr']);

                $stmt->bindParam(':CNAME', $_POST['courseName']);

                $stmt->execute();

                $quizVariants=$stmt->fetchAll(PDO::FETCH_NUM);

                        $randomIndex=rand(0,count($quizVariants)-1);

                        $quizVariant=$quizVariants[$randomIndex][0];

                        $quizVariantData=fetchQuizVariant($_POST['courseName'], $_POST['quizNr'], $quizVariant, $pdo);

                        //Store selected variant

                        $insertString="INSERT INTO AssignedQuizzes(ssn, quizNr, qVarNr, quizCourseName, courseOccasion) 

                                                   VALUES((SELECT Student.ssn FROM Student WHERE Student.loginName=:LOGIN), :QNR, :QVARNR, :CNAME, :COCCASION);";

                        $insertStmt->bindParam(':QVARNR', $quizVariant);  

                        $insertStmt->bindParam(':COCCASION', $_SESSION['courseOccasion']);

                        $insertStmt->execute();

                        echo json_encode($quizVariantData);     

                        exit();

                } else {