<?php
function sanitizeInput($data) {
    $data = trim($data);
    $data = stripslashes($data);
    $data = htmlspecialchars($data);
    return $data;
}

function jsonResponse($success, $message, $data = null, $statusCode = 200) {
    http_response_code($statusCode);
    header('Content-Type: application/json');
    echo json_encode([
        'success' => $success,
        'message' => $message,
        'data' => $data
    ]);
    exit;
}

function getCurrentUser() {
    session_start();
    if (isset($_SESSION['user_id'])) {
        $db = getDB();
        $stmt = $db->prepare("SELECT * FROM users WHERE id = ?");
        $stmt->execute([$_SESSION['user_id']]);
        return $stmt->fetch();
    }
    return null;
}

function isAdmin() {
    $user = getCurrentUser();
    return $user && $user['role'] === 'admin';
}

function formatTime($seconds) {
    $minutes = floor($seconds / 60);
    $seconds = floor($seconds % 60);
    return sprintf("%d:%02d", $minutes, $seconds);
}

function getFileUrl($path) {
    if (empty($path)) return '';
    if (filter_var($path, FILTER_VALIDATE_URL)) return $path;
    return getenv('APP_URL') . '/uploads/' . ltrim($path, '/');
}

function generateSlug($string) {
    $string = strtolower($string);
    $string = preg_replace('/[^a-z0-9-]/', '-', $string);
    $string = preg_replace('/-+/', '-', $string);
    return trim($string, '-');
}
?>