enum OptionCode: Int32 {
    case h = 0x68
    case u = 0x75
    case p = 0x70
    case firstLongOption = 0x100
    case host
}

extension StaticString {
    var ccharPointer: UnsafePointer<CChar> {
        let rawPointer = UnsafeRawPointer(utf8Start)
        return rawPointer.bindMemory(to: CChar.self, capacity: utf8CodeUnitCount)
    }
}

let longOpts: [option] = [
    option(name: ("help" as StaticString).ccharPointer, has_arg: no_argument, flag: nil, val: OptionCode.h.rawValue),
    option(name: ("username" as StaticString).ccharPointer, has_arg: required_argument, flag: nil, val: OptionCode.u.rawValue),
    option(name: ("password" as StaticString).ccharPointer, has_arg: required_argument, flag: nil, val: OptionCode.p.rawValue),
    option(name: ("host" as StaticString).ccharPointer, has_arg: required_argument, flag: nil, val: OptionCode.host.rawValue),
    option()
]

while case let opt = getopt_long(CommandLine.argc, CommandLine.unsafeArgv, "hu:p:", longOpts, nil), opt != -1 {
    switch opt {
    case OptionCode.u.rawValue:
        userName = String(cString: optarg)
    case OptionCode.p.rawValue:
        password = String(cString: optarg)
    case OptionCode.host.rawValue:
        host = URL(string: String(cString: optarg))!
    case OptionCode.h.rawValue:
        print("""
Options available:
 --username, -u: user name
 --password, -p: password
 --host: host
 --help, -h: show this help
""")
        exit(0)
    default:
        fatalError()
    }
}