<?php
// Flash message helper
function flash($name = '', $message = '', $class = 'alert alert-success') {
    if (!empty($name)) {
        if (!empty($message) && empty($_SESSION[$name])) {
            if (!empty($_SESSION[$name])) {
                unset($_SESSION[$name]);
            }
            if (!empty($_SESSION[$name . '_class'])) {
                unset($_SESSION[$name . '_class']);
            }
            $_SESSION[$name] = $message;
            $_SESSION[$name . '_class'] = $class;
        } elseif (empty($message) && !empty($_SESSION[$name])) {
            $class = !empty($_SESSION[$name . '_class']) ? $_SESSION[$name . '_class'] : '';
            echo '<div class="' . $class . '" id="msg-flash">' . $_SESSION[$name] . '</div>';
            unset($_SESSION[$name]);
            unset($_SESSION[$name . '_class']);
        }
    }
}

// Check if user is logged in
function isLoggedIn() {
    return isset($_SESSION['user_id']);
}

// Get current user role
function getUserRole() {
    return isset($_SESSION['user_role']) ? $_SESSION['user_role'] : null;
}

// Check if user has specific role
function hasRole($role) {
    return getUserRole() === $role;
}

// Sanitize input
function sanitize($input) {
    return htmlspecialchars(strip_tags(trim($input)));
}

// Format date
function formatDate($date) {
    return date('F j, Y', strtotime($date));
}

// Format time
function formatTime($time) {
    return date('g:i A', strtotime($time));
}

// Get file extension
function getFileExtension($filename) {
    return strtolower(pathinfo($filename, PATHINFO_EXTENSION));
}

// Check if file is allowed
function isAllowedFileType($filename) {
    $allowed = ['jpg', 'jpeg', 'png', 'gif', 'pdf', 'doc', 'docx', 'mp4', 'mp3', 'wav'];
    return in_array(getFileExtension($filename), $allowed);
}

// Generate random string
function generateRandomString($length = 10) {
    return substr(str_shuffle(str_repeat($x='0123456789abcdefghijklmnopqrstuvwxyz', ceil($length/strlen($x)))), 1, $length);
}

// Redirect helper
function redirect($page) {
    header('location: ' . APP_URL . '/' . $page);
    exit();
}