prepare("SELECT id, question_text FROM questions WHERE id = :id");
$stmt->execute(['id' => $question_id]);
$question = $stmt->fetch(PDO::FETCH_ASSOC);
if (!$question) {
return null;
}
$stmt = db()->prepare("SELECT id, answer_text FROM answers WHERE question_id = :id ORDER BY RAND()");
$stmt->execute(['id' => $question_id]);
$question['answers'] = $stmt->fetchAll(PDO::FETCH_ASSOC);
return $question;
} catch (PDOException $e) {
error_log("Error in get_question: " . $e->getMessage());
return null;
}
}
/**
* Fetches a set of random question IDs for a given category.
* @param string $category_name
* @param int $limit
* @return array
*/
function get_random_question_ids(string $category_name, int $limit): array {
try {
// First, get the category ID from the name
$cat_stmt = db()->prepare("SELECT id FROM categories WHERE name = :name");
$cat_stmt->execute(['name' => $category_name]);
$category = $cat_stmt->fetch(PDO::FETCH_ASSOC);
if (!$category) {
return [];
}
$category_id = $category['id'];
// Now, fetch the questions
$stmt = db()->prepare("SELECT id FROM questions WHERE category_id = :category_id ORDER BY RAND() LIMIT :limit");
$stmt->bindParam('category_id', $category_id, PDO::PARAM_INT);
$stmt->bindParam('limit', $limit, PDO::PARAM_INT);
$stmt->execute();
return $stmt->fetchAll(PDO::FETCH_COLUMN);
} catch (PDOException $e) {
error_log("Error in get_random_question_ids: " . $e->getMessage());
return [];
}
}
/**
* Checks if the provided answer is correct.
* @param int $answer_id
* @return bool
*/
function is_answer_correct(int $answer_id): bool {
try {
$stmt = db()->prepare("SELECT is_correct FROM answers WHERE id = :id");
$stmt->execute(['id' => $answer_id]);
$result = $stmt->fetch(PDO::FETCH_ASSOC);
return $result && $result['is_correct'];
} catch (PDOException $e) {
error_log("Error in is_answer_correct: " . $e->getMessage());
return false;
}
}
// --- State Initialization ---
$question_ids_str = '';
$current_index = 0;
$score = 0;
$category_name = '';
$is_quiz_finished = false;
// --- Logic ---
// Is this a POST request (user answered a question)?
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
// Retrieve state from the form
$question_ids_str = $_POST['question_ids'] ?? '';
$current_index = isset($_POST['current_index']) ? (int)$_POST['current_index'] : 0;
$score = isset($_POST['score']) ? (int)$_POST['score'] : 0;
$submitted_answer_id = isset($_POST['answer_id']) ? (int)$_POST['answer_id'] : 0;
// Check if the answer was correct
if ($submitted_answer_id > 0 && is_answer_correct($submitted_answer_id)) {
$score++;
}
// Move to the next question
$current_index++;
}
// Or is this a GET request (start of the quiz)?
else if (isset($_GET['action']) && $_GET['action'] === 'start') {
$category_name = $_GET['category'] ?? '';
if (!empty($category_name)) {
$question_ids = get_random_question_ids($category_name, $num_questions_per_quiz);
if (count($question_ids) < $num_questions_per_quiz) {
$error_message = "Non ci sono abbastanza domande (ne servono {$num_questions_per_quiz}) in questa categoria per iniziare il quiz.";
$is_quiz_finished = true; // Stop the quiz
} else {
$question_ids_str = implode(',', $question_ids);
}
} else {
$error_message = "Nome della categoria non valido.";
$is_quiz_finished = true; // Stop the quiz
}
}
$question_ids = !empty($question_ids_str) ? explode(',', $question_ids_str) : [];
$total_questions = count($question_ids);
// Check if the quiz is over
if ($current_index >= $total_questions && $total_questions > 0) {
$is_quiz_finished = true;
}
?>
Quiz in Corso - MAVI