app/Support/PlatformUrl.php

<?php

namespace App\Support;

class PlatformUrl
{
    public static function backendApp(): string
    {
        return self::base('backend_app_url') ?: rtrim((string) config('app.url'), '/');
    }

    public static function backendApi(): string
    {
        return self::base('backend_api_base_url') ?: rtrim(self::backendApp(), '/').'/api/v1';
    }

    public static function website(string $path = ''): string
    {
        return self::join(self::base('website_url'), $path);
    }

    public static function adminPortal(string $path = ''): string
    {
        return self::join(self::base('admin_portal_url'), $path);
    }

    public static function clientPortal(string $path = ''): string
    {
        return self::join(self::base('client_portal_url'), $path);
    }

    private static function base(string $key): string
    {
        return rtrim((string) config('platform.'.$key, ''), '/');
    }

    private static function join(string $base, string $path): string
    {
        $base = rtrim($base, '/');
        $path = trim($path);

        if ($base === '') {
            return '';
        }

        if ($path === '') {
            return $base;
        }

        return $base.'/'.ltrim($path, '/');
    }
}