lesavka/client/src/input/camera.rs

// client/src/input/camera.rs
use anyhow::Context;
use gst::prelude::*;
use gstreamer as gst;
use gstreamer_app as gst_app;
use lesavka_common::lesavka::VideoPacket;
use std::{
    io::Write,
    path::{Path, PathBuf},
    sync::{
        Arc,
        atomic::{AtomicBool, Ordering},
    },
    thread,
    time::Duration,
};

const CAMERA_PREVIEW_TAP_ENV: &str = "LESAVKA_UPLINK_CAMERA_PREVIEW";
const CAMERA_PREVIEW_WIDTH: i32 = 128;
const CAMERA_PREVIEW_HEIGHT: i32 = 72;

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
enum CameraSourceProfile {
    Raw,
    Mjpeg,
    AutoDecode,
}

fn env_u32(name: &str, default: u32) -> u32 {
    std::env::var(name)
        .ok()
        .and_then(|v| v.parse::<u32>().ok())
        .unwrap_or(default)
}

#[derive(Clone, Copy, Debug)]
pub enum CameraCodec {
    H264,
    Mjpeg,
}

#[derive(Clone, Copy, Debug)]
pub struct CameraConfig {
    pub codec: CameraCodec,
    pub width: u32,
    pub height: u32,
    pub fps: u32,
}

pub struct CameraCapture {
    #[allow(dead_code)] // kept alive to hold PLAYING state
    pipeline: gst::Pipeline,
    sink: gst_app::AppSink,
    preview_tap_running: Option<Arc<AtomicBool>>,
}

impl CameraCapture {
    pub fn new(device_fragment: Option<&str>, cfg: Option<CameraConfig>) -> anyhow::Result<Self> {
        gst::init().ok();

        // Select source: V4L2 device or test pattern
        let (src_desc, dev_label, allow_mjpg_source) = match device_fragment {
            Some(fragment)
                if fragment.eq_ignore_ascii_case("test")
                    || fragment.eq_ignore_ascii_case("videotestsrc") =>
            {
                let pattern =
                    std::env::var("LESAVKA_CAM_TEST_PATTERN").unwrap_or_else(|_| "smpte".into());
                (
                    format!("videotestsrc is-live=true pattern={pattern}"),
                    format!("videotestsrc:{pattern}"),
                    false,
                )
            }
            Some(path) if path.starts_with("/dev/") => (
                format!("v4l2src device={path} do-timestamp=true"),
                path.to_string(),
                true,
            ),
            Some(fragment) => {
                let dev = Self::find_device(fragment).unwrap_or_else(|| "/dev/video0".into());
                (format!("v4l2src device={dev} do-timestamp=true"), dev, true)
            }
            None => {
                let dev = "/dev/video0".to_string();
                (format!("v4l2src device={dev} do-timestamp=true"), dev, true)
            }
        };

        let output_mjpeg = cfg.map_or_else(
            || {
                std::env::var("LESAVKA_CAM_CODEC").ok().is_some_and(|v| {
                    matches!(v.to_ascii_lowercase().as_str(), "mjpeg" | "mjpg" | "jpeg")
                })
            },
            |cfg| matches!(cfg.codec, CameraCodec::Mjpeg),
        );
        let jpeg_quality = env_u32("LESAVKA_CAM_JPEG_QUALITY", 85).clamp(1, 100);
        let width = env_u32("LESAVKA_CAM_WIDTH", cfg.map_or(1280, |cfg| cfg.width));
        let height = env_u32("LESAVKA_CAM_HEIGHT", cfg.map_or(720, |cfg| cfg.height));
        let fps = env_u32("LESAVKA_CAM_FPS", cfg.map_or(25, |cfg| cfg.fps)).max(1);
        let keyframe_interval = env_u32("LESAVKA_CAM_KEYFRAME_INTERVAL", fps.min(5)).clamp(1, fps);
        let source_profile = camera_source_profile(allow_mjpg_source);
        let use_mjpg_source = source_profile == CameraSourceProfile::Mjpeg;
        let (enc, kf_prop) = if use_mjpg_source && !output_mjpeg {
            ("x264enc", Some("key-int-max"))
        } else {
            Self::choose_encoder()
        };
        match source_profile {
            CameraSourceProfile::Mjpeg if !output_mjpeg => {
                tracing::info!("📸 using MJPG source with software encode");
            }
            CameraSourceProfile::AutoDecode => {
                tracing::info!("📸 using auto-decoded webcam source (raw/MJPEG accepted)");
            }
            _ => {}
        }
        let enc_opts = Self::encoder_options(enc, kf_prop, keyframe_interval);
        if output_mjpeg {
            tracing::info!("📸 outputting MJPEG frames for UVC (quality={jpeg_quality})");
        } else {
            tracing::info!("📸 using encoder element: {enc}");
        }
        #[cfg(not(coverage))]
        let have_nvvidconv = gst::ElementFactory::find("nvvidconv").is_some();
        let (src_caps, preenc) = match enc {
            // ───────────────────────────────────────────────────────────────────
            // Jetson (has nvvidconv)      Desktop (falls back to videoconvert)
            // ───────────────────────────────────────────────────────────────────
            #[cfg(not(coverage))]
            "nvh264enc" if have_nvvidconv =>
                (format!(
                    "video/x-raw(memory:NVMM),format=NV12,width={width},height={height},framerate={fps}/1"
                ), "nvvidconv !"),
            #[cfg(not(coverage))]
            "nvh264enc" /* else */ =>
                (format!(
                    "video/x-raw,format=NV12,width={width},height={height},framerate={fps}/1"
                ), "videoconvert !"),
            #[cfg(not(coverage))]
            "vaapih264enc" =>
                (format!(
                    "video/x-raw,format=NV12,width={width},height={height},framerate={fps}/1"
                ), "videoconvert !"),
            _ =>
                (format!(
                    "video/x-raw,width={width},height={height},framerate={fps}/1"
                ), "videoconvert !"),
        };

        // let desc = format!(
        //     "v4l2src device={dev} do-timestamp=true ! {raw_caps},width=1280,height=720 ! \
        //     videoconvert ! {enc} key-int-max=30 ! \
        //     h264parse config-interval=-1 ! \
        //     appsink name=asink emit-signals=true max-buffers=60 drop=true"
        // );
        // tracing::debug!(%desc, "📸 pipeline-desc");
        // Build a pipeline that works for any of the three encoders.
        //  * nvh264enc needs NVMM memory caps;
        //  * vaapih264enc wants system-memory caps;
        //  * x264enc needs the usual raw caps.
        let preview_tap_path = camera_preview_tap_path();
        let raw_source_chain =
            camera_raw_source_chain(&src_desc, &src_caps, width, height, fps, source_profile);
        let desc = if preview_tap_path.is_some() {
            if output_mjpeg {
                if use_mjpg_source {
                    format!(
                        "{src_desc} ! \
                         image/jpeg,width={width},height={height},framerate={fps}/1 ! \
                         tee name=t \
                         t. ! queue max-size-buffers=30 leaky=downstream ! \
                              appsink name=asink emit-signals=true max-buffers=60 drop=true \
                         t. ! queue max-size-buffers=2 leaky=downstream ! jpegdec ! \
                              {}",
                        camera_preview_tap_branch()
                    )
                } else {
                    format!(
                        "{raw_source_chain} ! \
                         tee name=t \
                         t. ! queue max-size-buffers=30 leaky=downstream ! \
                              videoconvert ! jpegenc quality={jpeg_quality} ! \
                              appsink name=asink emit-signals=true max-buffers=60 drop=true \
                         t. ! queue max-size-buffers=2 leaky=downstream ! \
                              {}",
                        camera_preview_tap_branch()
                    )
                }
            } else if use_mjpg_source {
                format!(
                    "{src_desc} ! \
                     image/jpeg,width={width},height={height} ! \
                     jpegdec ! videorate ! video/x-raw,framerate={fps}/1 ! \
                     tee name=t \
                     t. ! queue max-size-buffers=30 leaky=downstream ! \
                          videoconvert ! {enc_opts} ! \
                          h264parse config-interval=-1 ! video/x-h264,stream-format=byte-stream,alignment=au ! \
                          appsink name=asink emit-signals=true max-buffers=60 drop=true \
                     t. ! queue max-size-buffers=2 leaky=downstream ! \
                          {}",
                    camera_preview_tap_branch()
                )
            } else {
                format!(
                    "{raw_source_chain} ! \
                     tee name=t \
                     t. ! queue max-size-buffers=30 leaky=downstream ! \
                          {preenc} {enc_opts} ! \
                          h264parse config-interval=-1 ! video/x-h264,stream-format=byte-stream,alignment=au ! \
                          appsink name=asink emit-signals=true max-buffers=60 drop=true \
                     t. ! queue max-size-buffers=2 leaky=downstream ! \
                          {}",
                    camera_preview_tap_branch()
                )
            }
        } else if output_mjpeg {
            if use_mjpg_source {
                format!(
                    "{src_desc} ! \
                     image/jpeg,width={width},height={height},framerate={fps}/1 ! \
                     queue max-size-buffers=30 leaky=downstream ! \
                     appsink name=asink emit-signals=true max-buffers=60 drop=true"
                )
            } else {
                format!(
                    "{raw_source_chain} ! \
                     videoconvert ! jpegenc quality={jpeg_quality} ! \
                     queue max-size-buffers=30 leaky=downstream ! \
                     appsink name=asink emit-signals=true max-buffers=60 drop=true"
                )
            }
        } else if use_mjpg_source {
            format!(
                "{src_desc} ! \
                 image/jpeg,width={width},height={height} ! \
                 jpegdec ! videorate ! video/x-raw,framerate={fps}/1 ! \
                 videoconvert ! {enc_opts} ! \
                 h264parse config-interval=-1 ! video/x-h264,stream-format=byte-stream,alignment=au ! \
                 queue max-size-buffers=30 leaky=downstream ! \
                 appsink name=asink emit-signals=true max-buffers=60 drop=true"
            )
        } else {
            format!(
                "{raw_source_chain} ! \
                 {preenc} {enc_opts} ! \
                 h264parse config-interval=-1 ! video/x-h264,stream-format=byte-stream,alignment=au ! \
                 queue max-size-buffers=30 leaky=downstream ! \
                 appsink name=asink emit-signals=true max-buffers=60 drop=true"
            )
        };
        tracing::info!(%enc, width, height, fps, ?desc, "📸 using encoder element");

        let pipeline: gst::Pipeline = gst::parse::launch(&desc)
            .context("gst parse_launch(cam)")?
            .downcast::<gst::Pipeline>()
            .expect("not a pipeline");

        tracing::debug!("📸 pipeline built OK – setting PLAYING…");
        let sink: gst_app::AppSink = pipeline
            .by_name("asink")
            .expect("appsink element not found")
            .downcast::<gst_app::AppSink>()
            .expect("appsink down‑cast");

        spawn_camera_bus_logger(&pipeline, dev_label.clone());
        if let Err(err) = pipeline.set_state(gst::State::Playing) {
            let _ = pipeline.set_state(gst::State::Null);
            return Err(err.into());
        }
        tracing::info!("📸 webcam pipeline ▶️ device={dev_label}");

        let preview_tap_running = if let Some(path) = preview_tap_path {
            let preview_sink = pipeline
                .by_name("preview_sink")
                .context("missing camera preview tap appsink")?
                .downcast::<gst_app::AppSink>()
                .expect("camera preview tap appsink");
            Some(spawn_camera_preview_tap(preview_sink, path))
        } else {
            None
        };

        Ok(Self {
            pipeline,
            sink,
            preview_tap_running,
        })
    }

    pub fn pull(&self) -> Option<VideoPacket> {
        let sample = self.sink.pull_sample().ok()?;
        let buf = sample.buffer()?;
        let map = buf.map_readable().ok()?;
        let pts = buf.pts().unwrap_or(gst::ClockTime::ZERO).nseconds() / 1_000;
        static FIRST_CAMERA_PACKET: AtomicBool = AtomicBool::new(false);
        if !FIRST_CAMERA_PACKET.swap(true, Ordering::Relaxed) {
            tracing::info!(
                bytes = map.as_slice().len(),
                pts_us = pts,
                "📸 upstream webcam frames flowing"
            );
        }
        Some(VideoPacket {
            id: 2,
            pts,
            data: map.as_slice().to_vec(),
            ..Default::default()
        })
    }

    /// Fuzzy‑match devices under `/dev/v4l/by-id`, preferring capture nodes
    #[cfg(not(coverage))]
    fn find_device(substr: &str) -> Option<String> {
        let wanted = substr.to_ascii_lowercase();
        let mut matches: Vec<_> = std::fs::read_dir("/dev/v4l/by-id")
            .ok()?
            .flatten()
            .filter_map(|e| {
                let p = e.path();
                let name = p.file_name()?.to_string_lossy().to_ascii_lowercase();
                if name.contains(&wanted) {
                    Some(p)
                } else {
                    None
                }
            })
            .collect();

        // deterministic order
        matches.sort();

        for p in matches {
            if let Ok(target) = std::fs::read_link(&p) {
                let dev = format!("/dev/{}", target.file_name()?.to_string_lossy());
                if Self::is_capture(&dev) {
                    return Some(dev);
                }
            }
        }
        None
    }

    #[cfg(coverage)]
    fn find_device(substr: &str) -> Option<String> {
        let wanted = substr.to_ascii_lowercase();
        let by_id_dir =
            std::env::var("LESAVKA_CAM_BY_ID_DIR").unwrap_or_else(|_| "/dev/v4l/by-id".to_string());
        let dev_root = std::env::var("LESAVKA_CAM_DEV_ROOT").unwrap_or_else(|_| "/dev".to_string());
        let mut matches: Vec<_> = std::fs::read_dir(by_id_dir)
            .ok()?
            .flatten()
            .filter_map(|e| {
                let p = e.path();
                let name = p.file_name()?.to_string_lossy().to_ascii_lowercase();
                if name.contains(&wanted) {
                    Some(p)
                } else {
                    None
                }
            })
            .collect();
        matches.sort();
        for p in matches {
            if let Ok(target) = std::fs::read_link(&p) {
                let dev = format!("{}/{}", dev_root, target.file_name()?.to_string_lossy());
                if Self::is_capture(&dev) {
                    return Some(dev);
                }
            }
        }
        None
    }

    #[cfg(not(coverage))]
    fn is_capture(dev: &str) -> bool {
        const V4L2_CAP_VIDEO_CAPTURE: u32 = 0x0000_0001;
        const V4L2_CAP_VIDEO_CAPTURE_MPLANE: u32 = 0x0000_1000;

        v4l::Device::with_path(dev)
            .ok()
            .and_then(|d| d.query_caps().ok())
            .map(|caps| {
                let bits = caps.capabilities.bits();
                (bits & V4L2_CAP_VIDEO_CAPTURE != 0) || (bits & V4L2_CAP_VIDEO_CAPTURE_MPLANE != 0)
            })
            .unwrap_or(false)
    }

    #[cfg(coverage)]
    fn is_capture(dev: &str) -> bool {
        dev.starts_with("/dev/video")
    }

    /// Cheap stub used when the web‑cam is disabled
    pub fn new_stub() -> Self {
        let pipeline = gst::Pipeline::new();
        let sink: gst_app::AppSink = gst::ElementFactory::make("appsink")
            .build()
            .expect("appsink")
            .downcast::<gst_app::AppSink>()
            .unwrap();
        Self {
            pipeline,
            sink,
            preview_tap_running: None,
        }
    }

    #[allow(dead_code)] // helper kept for future heuristics
    #[cfg(not(coverage))]
    fn pick_encoder() -> (&'static str, &'static str) {
        let encoders = &[
            ("nvh264enc", "video/x-raw(memory:NVMM),format=NV12"),
            ("vaapih264enc", "video/x-raw,format=NV12"),
            ("v4l2h264enc", "video/x-raw"), // RPi, Jetson, etc.
            ("x264enc", "video/x-raw"),     // software
        ];
        for (name, caps) in encoders {
            if gst::ElementFactory::find(name).is_some() {
                return (name, caps);
            }
        }
        // last resort – software
        ("x264enc", "video/x-raw")
    }

    #[cfg(coverage)]
    fn pick_encoder() -> (&'static str, &'static str) {
        ("x264enc", "video/x-raw")
    }

    #[cfg(not(coverage))]
    fn choose_encoder() -> (&'static str, Option<&'static str>) {
        if buildable_encoder("nvh264enc") {
            return (
                "nvh264enc",
                supported_encoder_property(
                    "nvh264enc",
                    &["iframeinterval", "idrinterval", "gop-size"],
                ),
            );
        }
        if buildable_encoder("vaapih264enc") {
            return (
                "vaapih264enc",
                supported_encoder_property("vaapih264enc", &["keyframe-period"]),
            );
        }
        if buildable_encoder("v4l2h264enc") {
            return (
                "v4l2h264enc",
                supported_encoder_property("v4l2h264enc", &["idrcount"]),
            );
        }
        ("x264enc", Some("key-int-max"))
    }

    #[cfg(coverage)]
    fn choose_encoder() -> (&'static str, Option<&'static str>) {
        match std::env::var("LESAVKA_CAM_TEST_ENCODER")
            .ok()
            .as_deref()
            .map(str::trim)
        {
            Some("nvh264enc") => ("nvh264enc", None),
            Some("vaapih264enc") => ("vaapih264enc", Some("keyframe-period")),
            Some("v4l2h264enc") => ("v4l2h264enc", Some("idrcount")),
            _ => ("x264enc", Some("key-int-max")),
        }
    }

    fn encoder_options(
        enc: &'static str,
        kf_prop: Option<&'static str>,
        keyframe_interval: u32,
    ) -> String {
        if enc == "x264enc" {
            let bitrate_kbit = env_u32("LESAVKA_CAM_H264_KBIT", 4500);
            let keyframe_opt = kf_prop
                .map(|property| format!(" {property}={keyframe_interval}"))
                .unwrap_or_default();
            format!(
                "{enc} tune=zerolatency speed-preset=faster bitrate={bitrate_kbit}{keyframe_opt}"
            )
        } else if let Some(property) = kf_prop {
            format!("{enc} {property}={keyframe_interval}")
        } else {
            enc.to_string()
        }
    }
}

/// Choose the pre-encoder webcam format path.
///
/// V4L2 webcams often expose 720p/30 as MJPEG only, so the default accepts
/// either raw frames or MJPEG unless the operator explicitly pins a format.
fn camera_source_profile(allow_v4l2_auto_decode: bool) -> CameraSourceProfile {
    if !allow_v4l2_auto_decode {
        return CameraSourceProfile::Raw;
    }
    if std::env::var("LESAVKA_CAM_MJPG").is_ok() {
        return CameraSourceProfile::Mjpeg;
    }
    match std::env::var("LESAVKA_CAM_FORMAT")
        .ok()
        .as_deref()
        .map(str::trim)
        .map(str::to_ascii_lowercase)
        .as_deref()
    {
        Some("mjpg" | "mjpeg" | "jpeg") => CameraSourceProfile::Mjpeg,
        Some("raw" | "yuyv" | "yuy2") => CameraSourceProfile::Raw,
        _ => CameraSourceProfile::AutoDecode,
    }
}

/// Build the source-to-raw-video chain consumed by the encoder and preview tap.
fn camera_raw_source_chain(
    src_desc: &str,
    src_caps: &str,
    width: u32,
    height: u32,
    fps: u32,
    profile: CameraSourceProfile,
) -> String {
    match profile {
        CameraSourceProfile::Raw => format!("{src_desc} ! {src_caps}"),
        CameraSourceProfile::Mjpeg => format!(
            "{src_desc} ! \
             image/jpeg,width={width},height={height},framerate={fps}/1 ! \
             jpegdec ! videoconvert ! videoscale ! videorate ! \
             video/x-raw,width={width},height={height},framerate={fps}/1"
        ),
        CameraSourceProfile::AutoDecode => format!(
            "{src_desc} ! \
             capsfilter caps=\"{}\" ! \
             decodebin ! videoconvert ! videoscale ! videorate ! \
             video/x-raw,width={width},height={height},framerate={fps}/1,pixel-aspect-ratio=1/1",
            camera_auto_decode_caps(width, height, fps)
        ),
    }
}

/// Caps string that lets decodebin negotiate either raw webcam frames or MJPEG.
fn camera_auto_decode_caps(width: u32, height: u32, fps: u32) -> String {
    format!(
        "video/x-raw,width=(int){width},height=(int){height},framerate=(fraction){fps}/1;image/jpeg,width=(int){width},height=(int){height},framerate=(fraction){fps}/1"
    )
}

fn camera_preview_tap_path() -> Option<PathBuf> {
    std::env::var(CAMERA_PREVIEW_TAP_ENV)
        .ok()
        .map(|value| value.trim().to_string())
        .filter(|value| !value.is_empty())
        .map(PathBuf::from)
}

fn camera_preview_tap_branch() -> String {
    format!(
        "videoconvert ! videoscale ! videorate ! \
         video/x-raw,format=RGBA,width={CAMERA_PREVIEW_WIDTH},height={CAMERA_PREVIEW_HEIGHT},framerate=10/1,pixel-aspect-ratio=1/1 ! \
         appsink name=preview_sink emit-signals=false sync=false max-buffers=1 drop=true"
    )
}

/// Publish tiny local preview frames so the launcher can prove uplink activity.
fn spawn_camera_preview_tap(sink: gst_app::AppSink, path: PathBuf) -> Arc<AtomicBool> {
    let running = Arc::new(AtomicBool::new(true));
    let thread_running = Arc::clone(&running);
    thread::spawn(move || {
        let mut wrote_first = false;
        let mut empty_polls = 0_u64;
        while thread_running.load(Ordering::Acquire) {
            if let Some(sample) = sink.try_pull_sample(gst::ClockTime::from_mseconds(250)) {
                empty_polls = 0;
                match write_camera_preview_tap(&path, &sample) {
                    Ok(info) => {
                        if !wrote_first {
                            wrote_first = true;
                            tracing::info!(
                                path = %path.display(),
                                width = info.width,
                                height = info.height,
                                stride = info.stride,
                                "📸 local uplink preview tap publishing frames"
                            );
                        }
                    }
                    Err(err) => {
                        tracing::debug!("📸 local uplink preview tap write failed: {err:#}");
                        thread::sleep(Duration::from_millis(100));
                    }
                }
            } else if !wrote_first {
                empty_polls += 1;
                if empty_polls == 20 || empty_polls.is_multiple_of(120) {
                    tracing::warn!(
                        path = %path.display(),
                        "📸 local uplink preview tap is still waiting for webcam frames"
                    );
                }
            }
        }
    });
    running
}

struct CameraPreviewTapInfo {
    width: i32,
    height: i32,
    stride: usize,
}

/// Atomically write one RGBA preview sample for the launcher status pane.
fn write_camera_preview_tap(
    path: &Path,
    sample: &gst::Sample,
) -> anyhow::Result<CameraPreviewTapInfo> {
    let caps = sample.caps().context("preview tap sample missing caps")?;
    let structure = caps
        .structure(0)
        .context("preview tap caps missing structure")?;
    let width = structure
        .get::<i32>("width")
        .context("preview tap caps missing width")?;
    let height = structure
        .get::<i32>("height")
        .context("preview tap caps missing height")?;
    let buffer = sample
        .buffer()
        .context("preview tap sample missing buffer")?;
    let map = buffer
        .map_readable()
        .context("preview tap buffer unreadable")?;
    let row_count = usize::try_from(height)
        .ok()
        .filter(|height| *height > 0)
        .unwrap_or(1);
    let stride = map.as_slice().len() / row_count;
    let tmp_path = path.with_extension("tmp");
    let mut file = std::fs::File::create(&tmp_path)
        .with_context(|| format!("creating {}", tmp_path.display()))?;
    writeln!(file, "LESAVKA_RGBA {width} {height} {stride}")?;
    file.write_all(map.as_slice())?;
    file.sync_all().ok();
    std::fs::rename(&tmp_path, path).with_context(|| format!("publishing {}", path.display()))?;
    Ok(CameraPreviewTapInfo {
        width,
        height,
        stride,
    })
}

/// Forward camera bus warnings/errors into the relay log with the device label.
fn spawn_camera_bus_logger(pipeline: &gst::Pipeline, device: String) {
    let Some(bus) = pipeline.bus() else {
        return;
    };
    std::thread::spawn(move || {
        use gst::MessageView::{Error, StateChanged, Warning};
        for msg in bus.iter_timed(gst::ClockTime::NONE) {
            match msg.view() {
                StateChanged(s)
                    if s.current() == gst::State::Playing
                        && msg.src().is_some_and(|source| {
                            source.type_() == gst::Pipeline::static_type()
                        }) =>
                {
                    tracing::info!(%device, "📸 camera pipeline ▶️");
                }
                Error(e) => tracing::error!(
                    %device,
                    "📸💥 camera: {} ({})",
                    e.error(),
                    e.debug().unwrap_or_default()
                ),
                Warning(w) => tracing::warn!(
                    %device,
                    "📸⚠️ camera: {} ({})",
                    w.error(),
                    w.debug().unwrap_or_default()
                ),
                _ => {}
            }
        }
    });
}

#[cfg(not(coverage))]
fn buildable_encoder(encoder: &'static str) -> bool {
    gst::ElementFactory::find(encoder).is_some()
        && gst::ElementFactory::make(encoder).build().is_ok()
}

#[cfg(not(coverage))]
fn supported_encoder_property(
    encoder: &'static str,
    properties: &[&'static str],
) -> Option<&'static str> {
    let element = gst::ElementFactory::make(encoder).build().ok()?;
    properties
        .iter()
        .copied()
        .find(|property| element.find_property(property).is_some())
}

impl Drop for CameraCapture {
    fn drop(&mut self) {
        if let Some(running) = &self.preview_tap_running {
            running.store(false, Ordering::Release);
        }
        let _ = self.pipeline.set_state(gst::State::Null);
    }
}