impl LesavkaClientApp {
    /*──────────────── mic stream ─────────────────*/
    #[cfg(not(coverage))]
    async fn voice_loop(
        ep: Channel,
        initial_source: Option<String>,
        telemetry: crate::uplink_telemetry::UplinkTelemetryHandle,
        media_controls: crate::live_media_control::LiveMediaControls,
    ) {
        let mut delay = Duration::from_secs(1);
        static FAIL_CNT: AtomicUsize = AtomicUsize::new(0);

        loop {
            let state = media_controls.refresh();
            if !state.microphone {
                telemetry.record_enabled(false);
                tokio::time::sleep(Duration::from_millis(100)).await;
                continue;
            }
            let microphone_source_choice = state.microphone_source.clone();
            let active_source = microphone_source_choice.resolve(initial_source.as_deref());
            let use_default_source = matches!(
                microphone_source_choice,
                crate::live_media_control::MediaDeviceChoice::Auto
            ) && active_source.is_none();
            let setup_source = active_source.clone();
            let result = tokio::task::spawn_blocking(move || {
                if use_default_source {
                    MicrophoneCapture::new_default_source()
                } else {
                    MicrophoneCapture::new_with_source(setup_source.as_deref())
                }
            })
            .await;
            let mic = match result {
                Ok(Ok(mic)) => Arc::new(mic),
                Ok(Err(err)) => {
                    telemetry.record_disconnect(format!("microphone uplink setup failed: {err:#}"));
                    warn!(
                        "🎤 microphone uplink setup failed for {:?}: {err:#}",
                        active_source.as_deref().unwrap_or("auto")
                    );
                    abort_if_required_media_source_failed("microphone", "🎤", active_source.as_deref(), &err);
                    delay = app_support::next_delay(delay);
                    tokio::time::sleep(delay).await;
                    continue;
                }
                Err(err) => {
                    telemetry.record_disconnect(format!("microphone uplink setup task failed: {err}"));
                    warn!("🎤 microphone uplink setup task failed before StreamMicrophone could start: {err}");
                    abort_if_required_media_source_failed(
                        "microphone",
                        "🎤",
                        active_source.as_deref(),
                        &err,
                    );
                    delay = app_support::next_delay(delay);
                    tokio::time::sleep(delay).await;
                    continue;
                }
            };

            telemetry.record_reconnect_attempt();
            let mut cli = RelayClient::new(ep.clone());
            let queue = crate::uplink_fresh_queue::FreshPacketQueue::new(AUDIO_UPLINK_QUEUE);
            let drop_log = Arc::new(std::sync::Mutex::new(UplinkDropLogLimiter::new(
                "microphone",
                "🎤",
            )));

            let queue_stream = queue.clone();
            let telemetry_stream = telemetry.clone();
            let drop_log_stream = Arc::clone(&drop_log);
            let outbound = async_stream::stream! {
                loop {
                    let next = queue_stream.pop_fresh().await;
                    if next.dropped_stale > 0 {
                        telemetry_stream.record_stale_drop(next.dropped_stale);
                        log_uplink_drop(
                            &drop_log_stream,
                            UplinkDropReason::Stale,
                            next.dropped_stale,
                            next.queue_depth,
                            duration_ms(next.delivery_age),
                        );
                    }
                    if let Some(mut packet) = next.packet {
                        telemetry_stream.record_streamed(
                            queue_depth_u32(next.queue_depth),
                            duration_ms(next.delivery_age),
                        );
                        attach_audio_timing_metadata(
                            &mut packet,
                            next.queue_depth,
                            next.delivery_age,
                        );
                        yield packet;
                        continue;
                    }
                    break;
                }
            };

            match cli.stream_microphone(Request::new(outbound)).await {
                Ok(mut resp) => {
                    let (stop_tx, stop_rx) = std::sync::mpsc::channel::<()>();
                    let mic_clone = mic.clone();
                    let telemetry_thread = telemetry.clone();
                    let queue_thread = queue.clone();
                    let drop_log_thread = Arc::clone(&drop_log);
                    let media_controls_thread = media_controls.clone();
                    let initial_source_thread = initial_source.clone();
                    let active_source_thread = active_source.clone();
                    let mic_worker = std::thread::spawn(move || {
                        let mut paused = false;
                        while stop_rx.try_recv().is_err() {
                            let state = media_controls_thread.refresh();
                            let desired_source = state
                                .microphone_source
                                .resolve(initial_source_thread.as_deref());
                            if desired_source != active_source_thread {
                                tracing::info!(
                                    from = active_source_thread.as_deref().unwrap_or("auto"),
                                    to = desired_source.as_deref().unwrap_or("auto"),
                                    "🎤 microphone source changed; restarting live uplink pipeline"
                                );
                                break;
                            }
                            if !state.microphone {
                                if !paused {
                                    telemetry_thread.record_enabled(false);
                                    tracing::info!("🎤 microphone uplink soft-paused");
                                    paused = true;
                                }
                                std::thread::sleep(Duration::from_millis(20));
                                continue;
                            }
                            if paused {
                                telemetry_thread.record_enabled(true);
                                tracing::info!("🎤 microphone uplink resumed");
                                paused = false;
                            }
                            if let Some(pkt) = mic_clone.pull() {
                                trace!("🎤📤 cli  {} bytes → gRPC", pkt.data.len());
                                let enqueue_age = crate::live_capture_clock::packet_age(pkt.pts);
                                let stats = queue_thread.push(pkt, enqueue_age);
                                if stats.dropped_queue_full > 0 {
                                    telemetry_thread.record_queue_full_drop(stats.dropped_queue_full);
                                    log_uplink_drop(
                                        &drop_log_thread,
                                        UplinkDropReason::QueueFull,
                                        stats.dropped_queue_full,
                                        stats.queue_depth,
                                        duration_ms(enqueue_age),
                                    );
                                }
                                telemetry_thread.record_enqueue(
                                    queue_depth_u32(stats.queue_depth),
                                    duration_ms(enqueue_age),
                                    0.0,
                                );
                            }
                        }
                    });
                    delay = Duration::from_secs(1);
                    telemetry.record_connected();
                    while resp.get_mut().message().await.transpose().is_some() {}
                    telemetry.record_disconnect("microphone uplink stream ended");
                    queue.close();
                    let _ = stop_tx.send(());
                    let _ = mic_worker.join();
                }
                Err(e) => {
                    telemetry.record_disconnect(format!("microphone uplink connect failed: {e}"));
                    if FAIL_CNT.fetch_add(1, Ordering::Relaxed) == 0 {
                        warn!("❌🎤 connect failed: {e}");
                        warn!("⚠️🎤 further microphone‑stream failures will be logged at DEBUG");
                    } else {
                        debug!("❌🎤 reconnect failed: {e}");
                    }
                    delay = app_support::next_delay(delay);
                }
            }

            queue.close();
            tokio::time::sleep(delay).await;
        }
    }

    /*──────────────── cam stream ───────────────────*/
    #[cfg(not(coverage))]
    async fn cam_loop(
        ep: Channel,
        initial_source: Option<String>,
        initial_profile: Option<String>,
        camera_cfg: Option<crate::input::camera::CameraConfig>,
        telemetry: crate::uplink_telemetry::UplinkTelemetryHandle,
        media_controls: crate::live_media_control::LiveMediaControls,
    ) {
        let mut delay = Duration::from_secs(1);

        loop {
            let state = media_controls.refresh();
            if !state.camera {
                telemetry.record_enabled(false);
                tokio::time::sleep(Duration::from_millis(100)).await;
                continue;
            }
            let active_source = state.camera_source.resolve(initial_source.as_deref());
            let active_profile = state.camera_profile.resolve(initial_profile.as_deref());
            let capture_profile = active_profile
                .as_deref()
                .and_then(parse_camera_profile_id);
            let setup_source = active_source.clone();
            let result = tokio::task::spawn_blocking(move || {
                CameraCapture::new_with_capture_profile(
                    setup_source.as_deref(),
                    camera_cfg,
                    capture_profile,
                )
            })
            .await;
            let cam = match result {
                Ok(Ok(cam)) => Arc::new(cam),
                Ok(Err(err)) => {
                    telemetry.record_disconnect(format!("webcam uplink setup failed: {err:#}"));
                    warn!(
                        "📸 webcam uplink setup failed for {:?}: {err:#}",
                        active_source.as_deref().unwrap_or("auto")
                    );
                    abort_if_required_media_source_failed("camera", "📸", active_source.as_deref(), &err);
                    delay = app_support::next_delay(delay);
                    tokio::time::sleep(delay).await;
                    continue;
                }
                Err(err) => {
                    telemetry.record_disconnect(format!("webcam uplink setup task failed: {err}"));
                    warn!("📸 webcam uplink setup task failed before StreamCamera could start: {err}");
                    abort_if_required_media_source_failed(
                        "camera",
                        "📸",
                        active_source.as_deref(),
                        &err,
                    );
                    delay = app_support::next_delay(delay);
                    tokio::time::sleep(delay).await;
                    continue;
                }
            };

            telemetry.record_reconnect_attempt();
            let mut cli = RelayClient::new(ep.clone());
            let queue = crate::uplink_fresh_queue::FreshPacketQueue::new(VIDEO_UPLINK_QUEUE);
            let drop_log =
                Arc::new(std::sync::Mutex::new(UplinkDropLogLimiter::new("camera", "📸")));

            let queue_stream = queue.clone();
            let telemetry_stream = telemetry.clone();
            let drop_log_stream = Arc::clone(&drop_log);
            let outbound = async_stream::stream! {
                loop {
                    let next = queue_stream.pop_fresh().await;
                    if next.dropped_stale > 0 {
                        telemetry_stream.record_stale_drop(next.dropped_stale);
                        log_uplink_drop(
                            &drop_log_stream,
                            UplinkDropReason::Stale,
                            next.dropped_stale,
                            next.queue_depth,
                            duration_ms(next.delivery_age),
                        );
                    }
                    if let Some(mut packet) = next.packet {
                        telemetry_stream.record_streamed(
                            queue_depth_u32(next.queue_depth),
                            duration_ms(next.delivery_age),
                        );
                        attach_video_timing_metadata(
                            &mut packet,
                            next.queue_depth,
                            next.delivery_age,
                        );
                        yield packet;
                        continue;
                    }
                    break;
                }
            };

            match cli.stream_camera(Request::new(outbound)).await {
                Ok(mut resp) => {
                    let (stop_tx, stop_rx) = std::sync::mpsc::channel::<()>();
                    let cam_worker = std::thread::spawn({
                        let cam = cam.clone();
                        let telemetry = telemetry.clone();
                        let queue = queue.clone();
                        let drop_log = Arc::clone(&drop_log);
                        let media_controls = media_controls.clone();
                        let initial_source_thread = initial_source.clone();
                        let active_source_thread = active_source.clone();
                        let initial_profile_thread = initial_profile.clone();
                        let active_profile_thread = active_profile.clone();
                        move || loop {
                            if stop_rx.try_recv().is_ok() {
                                break;
                            }
                            let state = media_controls.refresh();
                            let desired_source =
                                state.camera_source.resolve(initial_source_thread.as_deref());
                            let desired_profile =
                                state.camera_profile.resolve(initial_profile_thread.as_deref());
                            if desired_source != active_source_thread
                                || desired_profile != active_profile_thread
                            {
                                tracing::info!(
                                    from = active_source_thread.as_deref().unwrap_or("auto"),
                                    to = desired_source.as_deref().unwrap_or("auto"),
                                    "📸 webcam source changed; restarting live uplink pipeline"
                                );
                                break;
                            }
                            if !state.camera {
                                telemetry.record_enabled(false);
                                tracing::info!("📸 webcam uplink soft-paused");
                                while stop_rx.try_recv().is_err() {
                                    let state = media_controls.refresh();
                                    let desired_source =
                                        state.camera_source.resolve(initial_source_thread.as_deref());
                                    let desired_profile = state
                                        .camera_profile
                                        .resolve(initial_profile_thread.as_deref());
                                    if desired_source != active_source_thread
                                        || desired_profile != active_profile_thread
                                    {
                                        break;
                                    }
                                    if state.camera {
                                        break;
                                    }
                                    std::thread::sleep(Duration::from_millis(25));
                                }
                                if stop_rx.try_recv().is_ok() {
                                    break;
                                }
                                let state = media_controls.refresh();
                                let desired_source =
                                    state.camera_source.resolve(initial_source_thread.as_deref());
                                let desired_profile = state
                                    .camera_profile
                                    .resolve(initial_profile_thread.as_deref());
                                if desired_source != active_source_thread
                                    || desired_profile != active_profile_thread
                                {
                                    tracing::info!(
                                        from = active_source_thread.as_deref().unwrap_or("auto"),
                                        to = desired_source.as_deref().unwrap_or("auto"),
                                        "📸 webcam source changed while paused; restarting live uplink pipeline"
                                    );
                                    break;
                                }
                                telemetry.record_enabled(true);
                                tracing::info!("📸 webcam uplink resumed");
                            }
                            let Some(pkt) = cam.pull() else {
                                std::thread::sleep(Duration::from_millis(5));
                                continue;
                            };
                            static CNT: std::sync::atomic::AtomicU64 =
                                std::sync::atomic::AtomicU64::new(0);
                            let n = CNT.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
                            if n < 10 || n.is_multiple_of(120) {
                                tracing::trace!("📸 cli  frame#{n}  {} B", pkt.data.len());
                            }
                            tracing::trace!("📸⬆️ sent webcam AU pts={} {} B", pkt.pts, pkt.data.len());
                            let enqueue_age = crate::live_capture_clock::packet_age(pkt.pts);
                            let stats = queue.push(pkt, enqueue_age);
                            if stats.dropped_queue_full > 0 {
                                telemetry.record_queue_full_drop(stats.dropped_queue_full);
                                log_uplink_drop(
                                    &drop_log,
                                    UplinkDropReason::QueueFull,
                                    stats.dropped_queue_full,
                                    stats.queue_depth,
                                    duration_ms(enqueue_age),
                                );
                            }
                            telemetry.record_enqueue(
                                queue_depth_u32(stats.queue_depth),
                                duration_ms(enqueue_age),
                                0.0,
                            );
                        }
                    });
                    delay = Duration::from_secs(1);
                    telemetry.record_connected();
                    while resp.get_mut().message().await.transpose().is_some() {}
                    telemetry.record_disconnect("camera uplink stream ended");
                    queue.close();
                    let _ = stop_tx.send(());
                    let _ = cam_worker.join();
                }
                Err(e) if e.code() == tonic::Code::Unimplemented => {
                    tracing::warn!("📸 server does not support StreamCamera – giving up");
                    telemetry.record_disconnect("camera uplink unavailable on server");
                    queue.close();
                    return;
                }
                Err(e) => {
                    telemetry.record_disconnect(format!("camera uplink connect failed: {e}"));
                    tracing::warn!("❌📸 connect failed: {e:?}");
                    delay = app_support::next_delay(delay);
                }
            }

            queue.close();
            tokio::time::sleep(delay).await;
        }
    }
}

#[cfg(not(coverage))]
fn initial_camera_profile_id_from_env() -> Option<String> {
    let width = std::env::var("LESAVKA_CAM_WIDTH").ok()?;
    let height = std::env::var("LESAVKA_CAM_HEIGHT").ok()?;
    let fps = std::env::var("LESAVKA_CAM_FPS").ok()?;
    Some(format!("{width}x{height}@{fps}"))
}

#[cfg(not(coverage))]
fn parse_camera_profile_id(raw: &str) -> Option<(u32, u32, u32)> {
    let (size, fps) = raw.split_once('@')?;
    let (width, height) = size.split_once('x')?;
    let width = width.parse().ok()?;
    let height = height.parse().ok()?;
    let fps = fps.parse().ok()?;
    (width > 0 && height > 0 && fps > 0).then_some((width, height, fps))
}

#[cfg(not(coverage))]
fn abort_if_required_media_source_failed(
    kind: &str,
    icon: &str,
    source: Option<&str>,
    err: &dyn std::fmt::Display,
) {
    if !explicit_media_sources_required() || source.is_none_or(|source| source.trim().is_empty()) {
        return;
    }
    let source = source.expect("checked source presence");
    error!(
        "{icon} required {kind} source '{source}' failed to start; aborting client because LESAVKA_REQUIRE_EXPLICIT_MEDIA_SOURCES=1: {err}"
    );
    eprintln!(
        "{icon} required {kind} source '{source}' failed to start; aborting client because LESAVKA_REQUIRE_EXPLICIT_MEDIA_SOURCES=1: {err}"
    );
    std::process::exit(2);
}

#[cfg(not(coverage))]
fn explicit_media_sources_required() -> bool {
    std::env::var("LESAVKA_REQUIRE_EXPLICIT_MEDIA_SOURCES")
        .ok()
        .is_some_and(|value| {
            let value = value.trim();
            value == "1"
                || value.eq_ignore_ascii_case("true")
                || value.eq_ignore_ascii_case("yes")
                || value.eq_ignore_ascii_case("on")
        })
}

#[cfg(not(coverage))]
const VIDEO_UPLINK_QUEUE: crate::uplink_fresh_queue::FreshQueueConfig =
    crate::uplink_fresh_queue::FreshQueueConfig {
        capacity: 32,
        max_age: Duration::from_millis(350),
        policy: crate::uplink_fresh_queue::FreshQueuePolicy::LatestOnly,
    };

#[cfg(not(coverage))]
const AUDIO_UPLINK_QUEUE: crate::uplink_fresh_queue::FreshQueueConfig =
    crate::uplink_fresh_queue::FreshQueueConfig {
        capacity: 64,
        max_age: Duration::from_millis(400),
        policy: crate::uplink_fresh_queue::FreshQueuePolicy::DrainOldest,
    };

#[cfg(not(coverage))]
fn queue_depth_u32(depth: usize) -> u32 {
    depth.try_into().unwrap_or(u32::MAX)
}

#[cfg(not(coverage))]
fn duration_ms(duration: Duration) -> f32 {
    duration.as_secs_f32() * 1_000.0
}

#[cfg(not(coverage))]
fn duration_ms_u32(duration: Duration) -> u32 {
    duration.as_millis().min(u128::from(u32::MAX)) as u32
}

#[cfg(not(coverage))]
fn attach_audio_timing_metadata(
    packet: &mut AudioPacket,
    queue_depth: usize,
    delivery_age: Duration,
) {
    static AUDIO_SEQUENCE: AtomicU64 = AtomicU64::new(0);
    packet.seq = AUDIO_SEQUENCE.fetch_add(1, Ordering::Relaxed).saturating_add(1);
    packet.client_capture_pts_us = packet.pts;
    packet.client_send_pts_us = crate::live_capture_clock::capture_pts_us();
    packet.client_queue_depth = queue_depth_u32(queue_depth);
    packet.client_queue_age_ms = duration_ms_u32(delivery_age);
}

#[cfg(not(coverage))]
fn attach_video_timing_metadata(
    packet: &mut VideoPacket,
    queue_depth: usize,
    delivery_age: Duration,
) {
    static VIDEO_SEQUENCE: AtomicU64 = AtomicU64::new(0);
    packet.seq = VIDEO_SEQUENCE.fetch_add(1, Ordering::Relaxed).saturating_add(1);
    packet.client_capture_pts_us = packet.pts;
    packet.client_send_pts_us = crate::live_capture_clock::capture_pts_us();
    packet.client_queue_depth = queue_depth_u32(queue_depth);
    packet.client_queue_age_ms = duration_ms_u32(delivery_age);
}

#[cfg(not(coverage))]
#[derive(Clone, Copy, Debug)]
enum UplinkDropReason {
    QueueFull,
    Stale,
}

#[cfg(not(coverage))]
#[derive(Debug)]
struct UplinkDropLogLimiter {
    stream: &'static str,
    icon: &'static str,
    last_warn_at: Option<Instant>,
    suppressed_full: u64,
    suppressed_stale: u64,
}

#[cfg(not(coverage))]
/// Aggregate freshness-first upstream drops into periodic warnings per stream.
impl UplinkDropLogLimiter {
    fn new(stream: &'static str, icon: &'static str) -> Self {
        Self {
            stream,
            icon,
            last_warn_at: None,
            suppressed_full: 0,
            suppressed_stale: 0,
        }
    }

    /// Fold full-queue and stale-packet drops into one periodic warning.
    fn record(&mut self, reason: UplinkDropReason, count: u64, queue_depth: usize, age_ms: f32) {
        match reason {
            UplinkDropReason::QueueFull => {
                self.suppressed_full = self.suppressed_full.saturating_add(count)
            }
            UplinkDropReason::Stale => {
                self.suppressed_stale = self.suppressed_stale.saturating_add(count)
            }
        }

        let should_warn = self
            .last_warn_at
            .map(|last| last.elapsed() >= UPLINK_DROP_WARN_INTERVAL)
            .unwrap_or(true);
        if should_warn {
            warn!(
                stream = self.stream,
                dropped_queue_full = self.suppressed_full,
                dropped_stale = self.suppressed_stale,
                queue_depth,
                latest_age_ms = age_ms,
                "{} upstream {} queue is dropping stale/superseded packets to preserve live A/V sync",
                self.icon,
                self.stream
            );
            self.suppressed_full = 0;
            self.suppressed_stale = 0;
            self.last_warn_at = Some(Instant::now());
        } else {
            debug!(
                stream = self.stream,
                ?reason,
                count,
                queue_depth,
                latest_age_ms = age_ms,
                "upstream media queue drop suppressed from WARN noise"
            );
        }
    }
}

#[cfg(not(coverage))]
const UPLINK_DROP_WARN_INTERVAL: Duration = Duration::from_secs(5);

#[cfg(not(coverage))]
/// Report an upstream queue drop through the shared rate limiter.
fn log_uplink_drop(
    limiter: &Arc<std::sync::Mutex<UplinkDropLogLimiter>>,
    reason: UplinkDropReason,
    count: u64,
    queue_depth: usize,
    age_ms: f32,
) {
    if let Ok(mut limiter) = limiter.lock() {
        limiter.record(reason, count, queue_depth, age_ms);
    }
}