#[cfg(coverage)]
#[tonic::async_trait]
impl Relay for Handler {
    type StreamKeyboardStream = ReceiverStream<Result<KeyboardReport, Status>>;
    type StreamMouseStream = ReceiverStream<Result<MouseReport, Status>>;
    type CaptureVideoStream = VideoStream;
    type CaptureAudioStream = AudioStream;
    type StreamMicrophoneStream = ReceiverStream<Result<Empty, Status>>;
    type StreamCameraStream = ReceiverStream<Result<Empty, Status>>;

    async fn stream_keyboard(
        &self,
        req: Request<tonic::Streaming<KeyboardReport>>,
    ) -> Result<Response<Self::StreamKeyboardStream>, Status> {
        let (tx, rx) = tokio::sync::mpsc::channel(32);
        let kb = self.kb.clone();
        let report_delay = live_keyboard_report_delay();

        tokio::spawn(async move {
            let mut s = req.into_inner();
            while let Some(pkt) = s.next().await.transpose()? {
                let _ = runtime_support::write_hid_report(&kb, &hid_endpoint(0), &pkt.data).await;
                tx.send(Ok(pkt)).await.ok();
                if !report_delay.is_zero() {
                    #[cfg(not(coverage))]
                    tokio::time::sleep(report_delay).await;
                }
            }
            Ok::<(), Status>(())
        });

        Ok(Response::new(ReceiverStream::new(rx)))
    }

    async fn stream_mouse(
        &self,
        req: Request<tonic::Streaming<MouseReport>>,
    ) -> Result<Response<Self::StreamMouseStream>, Status> {
        let (tx, rx) = tokio::sync::mpsc::channel(32);
        let ms = self.ms.clone();

        tokio::spawn(async move {
            let mut s = req.into_inner();
            while let Some(pkt) = s.next().await.transpose()? {
                let _ = runtime_support::write_hid_report(&ms, &hid_endpoint(1), &pkt.data).await;
                tx.send(Ok(pkt)).await.ok();
            }
            Ok::<(), Status>(())
        });

        Ok(Response::new(ReceiverStream::new(rx)))
    }

    async fn stream_microphone(
        &self,
        req: Request<tonic::Streaming<AudioPacket>>,
    ) -> Result<Response<Self::StreamMicrophoneStream>, Status> {
        let uac_dev = std::env::var("LESAVKA_UAC_DEV").unwrap_or_else(|_| "hw:UAC2Gadget,0".into());
        let mut sink = runtime_support::open_voice_with_retry(&uac_dev)
            .await
            .map_err(|e| Status::internal(format!("{e:#}")))?;
        let (tx, rx) = tokio::sync::mpsc::channel(1);

        tokio::spawn(async move {
            let mut inbound = req.into_inner();
            while let Some(pkt) = inbound.next().await.transpose()? {
                sink.push(&pkt);
            }
            sink.finish();
            let _ = tx.send(Ok(Empty {})).await;
            Ok::<(), Status>(())
        });

        Ok(Response::new(ReceiverStream::new(rx)))
    }

    async fn stream_camera(
        &self,
        req: Request<tonic::Streaming<VideoPacket>>,
    ) -> Result<Response<Self::StreamCameraStream>, Status> {
        let cfg = camera::current_camera_config();
        let (session_id, relay) = self.camera_rt.activate(&cfg).await?;
        let camera_rt = self.camera_rt.clone();
        let (tx, rx) = tokio::sync::mpsc::channel(1);

        tokio::spawn(async move {
            let mut s = req.into_inner();
            while let Some(pkt) = s.next().await.transpose()? {
                if !camera_rt.is_active(session_id) {
                    break;
                }
                relay.feed(pkt);
            }
            tx.send(Ok(Empty {})).await.ok();
            Ok::<(), Status>(())
        });

        Ok(Response::new(ReceiverStream::new(rx)))
    }

    async fn capture_video(
        &self,
        req: Request<MonitorRequest>,
    ) -> Result<Response<Self::CaptureVideoStream>, Status> {
        self.capture_video_reply(req.into_inner()).await
    }

    async fn capture_audio(
        &self,
        _req: Request<MonitorRequest>,
    ) -> Result<Response<Self::CaptureAudioStream>, Status> {
        Err(Status::internal(
            "audio capture unavailable in coverage harness",
        ))
    }

    async fn paste_text(&self, req: Request<PasteRequest>) -> Result<Response<PasteReply>, Status> {
        self.paste_text_reply(req).await
    }

    async fn reset_usb(&self, _req: Request<Empty>) -> Result<Response<ResetUsbReply>, Status> {
        self.reset_usb_reply().await
    }

    async fn get_capture_power(
        &self,
        _req: Request<Empty>,
    ) -> Result<Response<CapturePowerState>, Status> {
        self.get_capture_power_reply().await
    }

    async fn set_capture_power(
        &self,
        req: Request<SetCapturePowerRequest>,
    ) -> Result<Response<CapturePowerState>, Status> {
        self.set_capture_power_reply(req).await
    }
}