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function cleanInput($data) {
    global $conn;
    return mysqli_real_escape_string($conn, htmlspecialchars(trim($data)));
}

function generateBookingID() {
    global $conn;
    $prefix = 'DC-';
    $result = $conn->query("SELECT MAX(CAST(SUBSTRING(booking_id, 4) AS UNSIGNED)) as max_id FROM bookings");
    $row = $result->fetch_assoc();
    $next_id = ($row['max_id'] ?? 9999) + 1;
    return $prefix . str_pad($next_id, 5, '0', STR_PAD_LEFT);
}

function generateInvoiceNo() {
    global $conn;
    $prefix = 'INV-';
    $result = $conn->query("SELECT MAX(CAST(SUBSTRING(invoice_no, 5) AS UNSIGNED)) as max_id FROM invoices");
    $row = $result->fetch_assoc();
    $next_id = ($row['max_id'] ?? 9999) + 1;
    return $prefix . str_pad($next_id, 5, '0', STR_PAD_LEFT);
}

function isLoggedIn() {
    return isset($_SESSION['customer_id']);
}

function isAdmin() {
    return isset($_SESSION['admin_id']);
}

function redirect($url) {
    header("Location: $url");
    exit;
}

function getSetting($key) {
    global $conn;
    $stmt = $conn->prepare("SELECT setting_value FROM settings WHERE setting_key = ?");
    $stmt->bind_param("s", $key);
    $stmt->execute();
    $result = $stmt->get_result();
    $row = $result->fetch_assoc();
    return $row ? $row['setting_value'] : '';
}

function getCategories() {
    global $conn;
    $result = $conn->query("SELECT * FROM categories WHERE status = 1 ORDER BY sort_order ASC");
    return $result->fetch_all(MYSQLI_ASSOC);
}

function getPackages($category_id = null) {
    global $conn;
    $sql = "SELECT p.*, c.name as category_name FROM packages p JOIN categories c ON p.category_id = c.id WHERE p.status = 1";
    if ($category_id) {
        $sql .= " AND p.category_id = " . intval($category_id);
    }
    $sql .= " ORDER BY p.sort_order ASC, p.id DESC";
    $result = $conn->query($sql);
    return $result->fetch_all(MYSQLI_ASSOC);
}

function getFeaturedPackages() {
    global $conn;
    $result = $conn->query("SELECT p.*, c.name as category_name FROM packages p JOIN categories c ON p.category_id = c.id WHERE p.status = 1 AND p.is_featured = 1 ORDER BY p.sort_order ASC LIMIT 3");
    return $result->fetch_all(MYSQLI_ASSOC);
}

function getPackage($id) {
    global $conn;
    $stmt = $conn->prepare("SELECT p.*, c.name as category_name, c.slug as category_slug FROM packages p JOIN categories c ON p.category_id = c.id WHERE p.id = ?");
    $stmt->bind_param("i", $id);
    $stmt->execute();
    return $stmt->get_result()->fetch_assoc();
}

function getPackageImages($package_id) {
    global $conn;
    $stmt = $conn->prepare("SELECT * FROM package_images WHERE package_id = ? ORDER BY sort_order ASC");
    $stmt->bind_param("i", $package_id);
    $stmt->execute();
    return $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
}

function getGallery($category_id = null) {
    global $conn;
    $sql = "SELECT g.*, c.name as category_name FROM gallery g LEFT JOIN categories c ON g.category_id = c.id WHERE g.status = 1";
    if ($category_id) {
        $sql .= " AND g.category_id = " . intval($category_id);
    }
    $sql .= " ORDER BY g.sort_order ASC, g.id DESC";
    return $conn->query($sql)->fetch_all(MYSQLI_ASSOC);
}

function getRentalItems($category_id = null) {
    global $conn;
    $sql = "SELECT r.*, rc.name as category_name FROM rental_items r JOIN rental_categories rc ON r.category_id = rc.id WHERE r.status = 1";
    if ($category_id) {
        $sql .= " AND r.category_id = " . intval($category_id);
    }
    $sql .= " ORDER BY r.id DESC";
    return $conn->query($sql)->fetch_all(MYSQLI_ASSOC);
}

function getRentalCategories() {
    global $conn;
    return $conn->query("SELECT * FROM rental_categories WHERE status = 1 ORDER BY sort_order ASC")->fetch_all(MYSQLI_ASSOC);
}

function getTestimonials() {
    global $conn;
    return $conn->query("SELECT * FROM testimonials WHERE status = 1 ORDER BY sort_order ASC, id DESC")->fetch_all(MYSQLI_ASSOC);
}

function getBookings($customer_id = null) {
    global $conn;
    $sql = "SELECT b.*, p.name as package_name, c.name as category_name FROM bookings b JOIN packages p ON b.package_id = p.id JOIN categories c ON b.category_id = c.id";
    if ($customer_id) {
        $sql .= " WHERE b.customer_id = " . intval($customer_id);
    }
    $sql .= " ORDER BY b.created_at DESC";
    return $conn->query($sql)->fetch_all(MYSQLI_ASSOC);
}

function getBooking($id) {
    global $conn;
    $stmt = $conn->prepare("SELECT b.*, p.name as package_name, p.description as package_description, c.name as category_name, cu.name as customer_name, cu.email as customer_email, cu.phone as customer_phone FROM bookings b JOIN packages p ON b.package_id = p.id JOIN categories c ON b.category_id = c.id JOIN customers cu ON b.customer_id = cu.id WHERE b.id = ?");
    $stmt->bind_param("i", $id);
    $stmt->execute();
    return $stmt->get_result()->fetch_assoc();
}

function getCustomer($id) {
    global $conn;
    $stmt = $conn->prepare("SELECT * FROM customers WHERE id = ?");
    $stmt->bind_param("i", $id);
    $stmt->execute();
    return $stmt->get_result()->fetch_assoc();
}

function getPayments($booking_id) {
    global $conn;
    $stmt = $conn->prepare("SELECT * FROM payments WHERE booking_id = ? ORDER BY created_at DESC");
    $stmt->bind_param("i", $booking_id);
    $stmt->execute();
    return $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
}

function getNotifications($user_type = 'admin', $limit = 5) {
    global $conn;
    $stmt = $conn->prepare("SELECT * FROM notifications WHERE user_type = ? ORDER BY created_at DESC LIMIT ?");
    $stmt->bind_param("si", $user_type, $limit);
    $stmt->execute();
    return $stmt->get_result()->fetch_all(MYSQLI_ASSOC);
}

function getUnreadNotifications($user_type = 'admin') {
    global $conn;
    $stmt = $conn->prepare("SELECT COUNT(*) as count FROM notifications WHERE user_type = ? AND is_read = 0");
    $stmt->bind_param("s", $user_type);
    $stmt->execute();
    return $stmt->get_result()->fetch_assoc()['count'];
}

function addNotification($title, $message, $link = null, $user_type = 'admin', $user_id = null) {
    global $conn;
    $stmt = $conn->prepare("INSERT INTO notifications (user_id, user_type, title, message, link) VALUES (?, ?, ?, ?, ?)");
    $stmt->bind_param("issss", $user_id, $user_type, $title, $message, $link);
    return $stmt->execute();
}

function addActivityLog($action, $description, $user_type = null, $user_id = null) {
    global $conn;
    $ip = $_SERVER['REMOTE_ADDR'] ?? '';
    $ua = $_SERVER['HTTP_USER_AGENT'] ?? '';
    $stmt = $conn->prepare("INSERT INTO activity_logs (user_id, user_type, action, description, ip_address, user_agent) VALUES (?, ?, ?, ?, ?, ?)");
    $stmt->bind_param("isssss", $user_id, $user_type, $action, $description, $ip, $ua);
    return $stmt->execute();
}

function timeAgo($datetime) {
    $time = strtotime($datetime);
    $diff = time() - $time;
    $units = [
        31536000 => 'year', 2592000 => 'month', 604800 => 'week',
        86400 => 'day', 3600 => 'hour', 60 => 'minute', 1 => 'second'
    ];
    foreach ($units as $unit => $name) {
        if ($diff >= $unit) {
            $count = floor($diff / $unit);
            return $count . ' ' . $name . ($count > 1 ? 's' : '') . ' ago';
        }
    }
    return 'just now';
}

function formatPrice($amount) {
    $currency = getSetting('currency') ?: 'LKR';
    return $currency . ' ' . number_format($amount, 2);
}

function getStatusBadge($status) {
    $badges = [
        'pending' => 'warning',
        'approved' => 'info',
        'waiting_payment' => 'secondary',
        'confirmed' => 'primary',
        'completed' => 'success',
        'cancelled' => 'danger',
        'advance_paid' => 'info',
        'full_paid' => 'success',
        'available' => 'success',
        'blocked' => 'danger',
        'holiday' => 'warning',
        'booked' => 'secondary',
    ];
    $class = $badges[$status] ?? 'secondary';
    return "<span class='badge bg-{$class}'>{$status}</span>";
}

function uploadFile($file, $target_dir, $allowed_types = ['jpg','jpeg','png','gif','webp']) {
    $ext = strtolower(pathinfo($file['name'], PATHINFO_EXTENSION));
    if (!in_array($ext, $allowed_types)) return false;
    $filename = time() . '_' . bin2hex(random_bytes(8)) . '.' . $ext;
    $target_file = $target_dir . $filename;
    if (move_uploaded_file($file['tmp_name'], $target_file)) return $filename;
    return false;
}

function checkAvailability($date) {
    global $conn;
    $stmt = $conn->prepare("SELECT * FROM availability WHERE date = ?");
    $stmt->bind_param("s", $date);
    $stmt->execute();
    $result = $stmt->get_result()->fetch_assoc();
    if ($result && $result['status'] !== 'available') return false;
    $stmt = $conn->prepare("SELECT COUNT(*) as count FROM bookings WHERE event_date = ? AND status NOT IN ('cancelled')");
    $stmt->bind_param("s", $date);
    $stmt->execute();
    $count = $stmt->get_result()->fetch_assoc()['count'];
    return $count < 3;
}