type TCPKeepalive struct {
	KeepaliveProbes   *wrappers.UInt32Value `json:"keepalive_probes,omitempty"`
	KeepaliveTime     *wrappers.UInt32Value `json:"keepalive_time,omitempty"`
	KeepaliveInterval *wrappers.UInt32Value `json:"keepalive_interval,omitempty"`
}

// UpstreamConnectionOptions wraps is a thin JSON for xDS proto
type UpstreamConnectionOptions struct {

// SetKeepAlivePeriod sets the duration the connection needs to
// remain idle before TCP starts sending keepalive probes.
//
// Note that calling this method on Windows prior to Windows 10 version 1709
// will reset the KeepAliveInterval to the default system value, which is normally 1 second.
func (c *TCPConn) SetKeepAlivePeriod(d time.Duration) error {
	if !c.ok() {
		return syscall.EINVAL
	}
	if err := setKeepAliveIdle(c.fd, d); err != nil {

		if err != nil {
			return nil, err
		}

		keepAliveIntervalEnv := target.EnvMQTTKeepAliveInterval
		if k != config.Default {
			keepAliveIntervalEnv = keepAliveIntervalEnv + config.Default + k
		}
		keepAliveInterval, err := time.ParseDuration(env.Get(keepAliveIntervalEnv,
			kv.Get(target.MqttKeepAliveInterval)))
		if err != nil {
			return nil, err
		}

		queueLimitEnv := target.EnvMQTTQueueLimit

		c.UpstreamConnectionOptions.TcpKeepalive.KeepaliveTime = &wrappers.UInt32Value{Value: uint32(keepalive.Time.Seconds)}
	}

	if keepalive.Interval != nil {
		c.UpstreamConnectionOptions.TcpKeepalive.KeepaliveInterval = &wrappers.UInt32Value{Value: uint32(keepalive.Interval.Seconds)}
	}
}

// Build a struct which contains service metadata and will be added into cluster label.