// lesavka-server - gadget cycle guarded by env
// server/src/main.rs
#[allow(clippy::useless_attribute)]
#[forbid(unsafe_code)]
use futures_util::{Stream, StreamExt};
use std::sync::atomic::AtomicBool;
use std::{backtrace::Backtrace, panic, pin::Pin, sync::Arc, time::Duration};
use tokio::sync::Mutex;
use tokio_stream::wrappers::ReceiverStream;
use tonic::transport::Server;
use tonic::{Request, Response, Status};
use tonic_reflection::server::Builder as ReflBuilder;
use tracing::{debug, error, info, warn};

use lesavka_common::lesavka::{
    AudioPacket, CapturePowerCommand, CapturePowerState, Empty, KeyboardReport, MonitorRequest,
    MouseReport, PasteReply, PasteRequest, ResetUsbReply, SetCapturePowerRequest, VideoPacket,
    relay_server::{Relay, RelayServer},
};

use lesavka_server::{
    audio, camera, camera_runtime::CameraRuntime, capture_power::CapturePowerManager,
    gadget::UsbGadget, handshake::HandshakeSvc, paste, runtime_support,
    runtime_support::init_tracing, uvc_runtime, video,
};

/*──────────────── constants ────────────────*/
const PKG_NAME: &str = env!("CARGO_PKG_NAME");

type VideoStream = Pin<Box<dyn Stream<Item = Result<VideoPacket, Status>> + Send>>;
type AudioStream = Pin<Box<dyn Stream<Item = Result<AudioPacket, Status>> + Send>>;

fn hid_endpoint(index: u8) -> String {
    std::env::var("LESAVKA_HID_DIR")
        .map(|dir| format!("{dir}/hidg{index}"))
        .unwrap_or_else(|_| format!("/dev/hidg{index}"))
}

fn live_keyboard_report_delay() -> Duration {
    std::env::var("LESAVKA_LIVE_KEYBOARD_REPORT_DELAY_MS")
        .ok()
        .and_then(|value| value.parse::<u64>().ok())
        .map(Duration::from_millis)
        .unwrap_or_else(|| Duration::from_millis(8))
}

/*──────────────── Handler ───────────────────*/
struct Handler {
    kb: Arc<Mutex<tokio::fs::File>>,
    ms: Arc<Mutex<tokio::fs::File>>,
    gadget: UsbGadget,
    did_cycle: Arc<AtomicBool>,
    camera_rt: Arc<CameraRuntime>,
    capture_power: CapturePowerManager,
}

impl Handler {
    async fn new(gadget: UsbGadget) -> anyhow::Result<Self> {
        #[cfg(not(coverage))]
        if runtime_support::allow_gadget_cycle() {
            info!("🛠️  Initial USB reset…");
            let _ = gadget.cycle(); // ignore failure - may boot without host
        }
        #[cfg(not(coverage))]
        {
            if !runtime_support::allow_gadget_cycle() {
                info!(
                    "🔒 gadget cycle disabled at startup (set LESAVKA_ALLOW_GADGET_CYCLE=1 to enable)"
                );
            }
            info!("🛠️  opening HID endpoints …");
        }
        let kb = runtime_support::open_with_retry(&hid_endpoint(0)).await?;
        let ms = runtime_support::open_with_retry(&hid_endpoint(1)).await?;
        #[cfg(not(coverage))]
        info!("✅ HID endpoints ready");

        Ok(Self {
            kb: Arc::new(Mutex::new(kb)),
            ms: Arc::new(Mutex::new(ms)),
            gadget,
            did_cycle: Arc::new(AtomicBool::new(false)),
            camera_rt: Arc::new(CameraRuntime::new()),
            capture_power: CapturePowerManager::new(),
        })
    }

    async fn reopen_hid(&self) -> anyhow::Result<()> {
        let kb_new = runtime_support::open_with_retry(&hid_endpoint(0)).await?;
        let ms_new = runtime_support::open_with_retry(&hid_endpoint(1)).await?;
        *self.kb.lock().await = kb_new;
        *self.ms.lock().await = ms_new;
        Ok(())
    }

    async fn capture_video_reply(
        &self,
        req: MonitorRequest,
    ) -> Result<Response<VideoStream>, Status> {
        let id = req.id;
        let source_id = req.source_id.unwrap_or(id);
        let dev = match source_id {
            0 => "/dev/lesavka_l_eye",
            1 => "/dev/lesavka_r_eye",
            _ => return Err(Status::invalid_argument("source id must be 0 or 1")),
        };

        #[cfg(not(coverage))]
        {
            let rpc_id = runtime_support::next_stream_id();
            info!(
                rpc_id,
                id,
                source_id,
                max_bitrate = req.max_bitrate,
                requested_width = req.requested_width,
                requested_height = req.requested_height,
                requested_fps = req.requested_fps,
                "🎥 capture_video opened"
            );
            debug!(rpc_id, "🎥 streaming {dev}");
        }

        let lease = self.capture_power.acquire().await;
        let stream = video::eye_ball_with_request(
            dev,
            id,
            req.max_bitrate,
            req.requested_width,
            req.requested_height,
            req.requested_fps,
        )
        .await
        .map_err(|e| Status::internal(format!("{e:#}")))?;
        Ok(Response::new(Box::pin(GuardedVideoStream {
            inner: stream,
            _lease: lease,
        })))
    }

    async fn paste_text_reply(
        &self,
        req: Request<PasteRequest>,
    ) -> Result<Response<PasteReply>, Status> {
        let req = req.into_inner();
        let text = paste::decrypt(&req).map_err(|e| Status::unauthenticated(format!("{e}")))?;
        if let Err(e) = paste::type_text(self.kb.as_ref(), &text).await {
            return Ok(Response::new(PasteReply {
                ok: false,
                error: format!("{e}"),
            }));
        }
        Ok(Response::new(PasteReply {
            ok: true,
            error: String::new(),
        }))
    }

    async fn reset_usb_reply(&self) -> Result<Response<ResetUsbReply>, Status> {
        #[cfg(not(coverage))]
        info!("🔴 explicit ResetUsb() called");

        match self.gadget.cycle() {
            Ok(_) => {
                if let Err(e) = self.reopen_hid().await {
                    #[cfg(not(coverage))]
                    error!("💥 reopen HID failed: {e:#}");
                    return Err(Status::internal(e.to_string()));
                }
                Ok(Response::new(ResetUsbReply { ok: true }))
            }
            Err(e) => {
                #[cfg(not(coverage))]
                error!("💥 cycle failed: {e:#}");
                Err(Status::internal(e.to_string()))
            }
        }
    }

    async fn get_capture_power_reply(&self) -> Result<Response<CapturePowerState>, Status> {
        self.capture_power
            .snapshot()
            .await
            .map(Response::new)
            .map_err(|e| Status::internal(format!("{e:#}")))
    }

    async fn set_capture_power_reply(
        &self,
        req: Request<SetCapturePowerRequest>,
    ) -> Result<Response<CapturePowerState>, Status> {
        let req = req.into_inner();
        let result = match CapturePowerCommand::try_from(req.command)
            .unwrap_or(CapturePowerCommand::Unspecified)
        {
            CapturePowerCommand::Auto => self.capture_power.set_auto().await,
            CapturePowerCommand::ForceOn => self.capture_power.set_manual(true).await,
            CapturePowerCommand::ForceOff => self.capture_power.set_manual(false).await,
            CapturePowerCommand::Unspecified => self.capture_power.set_manual(req.enabled).await,
        };
        result
            .map(Response::new)
            .map_err(|e| Status::internal(format!("{e:#}")))
    }
}

struct GuardedVideoStream<S> {
    inner: S,
    _lease: lesavka_server::capture_power::CapturePowerLease,
}

impl<S> Stream for GuardedVideoStream<S>
where
    S: Stream<Item = Result<VideoPacket, Status>> + Unpin,
{
    type Item = Result<VideoPacket, Status>;

    fn poll_next(
        mut self: Pin<&mut Self>,
        cx: &mut std::task::Context<'_>,
    ) -> std::task::Poll<Option<Self::Item>> {
        Pin::new(&mut self.inner).poll_next(cx)
    }
}

/*──────────────── gRPC service ─────────────*/
#[cfg(not(coverage))]
#[tonic::async_trait]
impl Relay for Handler {
    /* existing streams ─ unchanged, except: no more auto-reset */
    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 rpc_id = runtime_support::next_stream_id();
        info!(rpc_id, "⌨️ stream_keyboard opened");
        let (tx, rx) = tokio::sync::mpsc::channel(32);
        let kb = self.kb.clone();
        let ms = self.ms.clone();
        let gadget = self.gadget.clone();
        let did_cycle = self.did_cycle.clone();
        let session_lease = self.capture_power.acquire_session().await;
        let report_delay = live_keyboard_report_delay();

        tokio::spawn(async move {
            let _session_lease = session_lease;
            let mut s = req.into_inner();
            while let Some(pkt) = s.next().await.transpose()? {
                if let Err(e) = runtime_support::write_hid_report(&kb, &pkt.data).await {
                    if e.raw_os_error() == Some(libc::EAGAIN) {
                        debug!(rpc_id, "⌨️  write would block (dropped)");
                    } else {
                        warn!(rpc_id, "⌨️  write failed: {e} (dropped)");
                        runtime_support::recover_hid_if_needed(
                            &e,
                            gadget.clone(),
                            kb.clone(),
                            ms.clone(),
                            did_cycle.clone(),
                        )
                        .await;
                    }
                }
                tx.send(Ok(pkt)).await.ok();
                if !report_delay.is_zero() {
                    tokio::time::sleep(report_delay).await;
                }
            }
            info!(rpc_id, "⌨️ stream_keyboard closed");
            Ok::<(), Status>(())
        });

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

    async fn stream_mouse(
        &self,
        req: Request<tonic::Streaming<MouseReport>>,
    ) -> Result<Response<Self::StreamMouseStream>, Status> {
        let rpc_id = runtime_support::next_stream_id();
        info!(rpc_id, "🖱️ stream_mouse opened");
        let (tx, rx) = tokio::sync::mpsc::channel(1024);
        let ms = self.ms.clone();
        let kb = self.kb.clone();
        let gadget = self.gadget.clone();
        let did_cycle = self.did_cycle.clone();
        let session_lease = self.capture_power.acquire_session().await;

        tokio::spawn(async move {
            let _session_lease = session_lease;
            let mut s = req.into_inner();
            while let Some(pkt) = s.next().await.transpose()? {
                if let Err(e) = runtime_support::write_hid_report(&ms, &pkt.data).await {
                    if e.raw_os_error() == Some(libc::EAGAIN) {
                        debug!(rpc_id, "🖱️  write would block (dropped)");
                    } else {
                        warn!(rpc_id, "🖱️  write failed: {e} (dropped)");
                        runtime_support::recover_hid_if_needed(
                            &e,
                            gadget.clone(),
                            kb.clone(),
                            ms.clone(),
                            did_cycle.clone(),
                        )
                        .await;
                    }
                }
                tx.send(Ok(pkt)).await.ok();
            }
            info!(rpc_id, "🖱️ stream_mouse closed");
            Ok::<(), Status>(())
        });

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

    async fn stream_microphone(
        &self,
        req: Request<tonic::Streaming<AudioPacket>>,
    ) -> Result<Response<Self::StreamMicrophoneStream>, Status> {
        let rpc_id = runtime_support::next_stream_id();
        info!(rpc_id, "🎤 stream_microphone opened");
        // 1 ─ build once, early
        let uac_dev = std::env::var("LESAVKA_UAC_DEV").unwrap_or_else(|_| "hw:UAC2Gadget,0".into());
        info!(%uac_dev, "🎤 stream_microphone using UAC sink");
        let mut sink = runtime_support::open_voice_with_retry(&uac_dev)
            .await
            .map_err(|e| Status::internal(format!("{e:#}")))?;

        // 2 ─ dummy outbound stream (same trick as before)
        let (tx, rx) = tokio::sync::mpsc::channel(1);

        // 3 ─ drive the sink in a background task
        tokio::spawn(async move {
            let mut inbound = req.into_inner();
            static CNT: std::sync::atomic::AtomicU64 = std::sync::atomic::AtomicU64::new(0);

            while let Some(pkt) = inbound.next().await.transpose()? {
                let n = CNT.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
                if n < 10 || n % 300 == 0 {
                    tracing::trace!(rpc_id, "🎤⬇ srv  pkt#{n}  {} bytes", pkt.data.len());
                }
                sink.push(&pkt);
            }
            sink.finish(); // flush on EOS
            let _ = tx.send(Ok(Empty {})).await;
            info!(rpc_id, "🎤 stream_microphone closed");
            Ok::<(), Status>(())
        });

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

    async fn stream_camera(
        &self,
        req: Request<tonic::Streaming<VideoPacket>>,
    ) -> Result<Response<Self::StreamCameraStream>, Status> {
        let rpc_id = runtime_support::next_stream_id();
        let cfg = camera::current_camera_config();
        info!(
            rpc_id,
            output = cfg.output.as_str(),
            codec = cfg.codec.as_str(),
            width = cfg.width,
            height = cfg.height,
            fps = cfg.fps,
            hdmi = cfg.hdmi.as_ref().map(|h| h.name.as_str()).unwrap_or("none"),
            "🎥 stream_camera output selected"
        );

        let (session_id, relay) = self.camera_rt.activate(&cfg).await?;
        let camera_rt = self.camera_rt.clone();
        info!(rpc_id, session_id, "🎥 stream_camera opened");

        // dummy outbound (same pattern as other streams)
        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) {
                    info!(rpc_id, session_id, "🎥 stream_camera session superseded");
                    break;
                }
                relay.feed(pkt); // ← all logging inside video.rs
            }
            tx.send(Ok(Empty {})).await.ok();
            info!(rpc_id, session_id, "🎥 stream_camera closed");
            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> {
        let rpc_id = runtime_support::next_stream_id();
        // Only one speaker stream for now; both 0/1 → same ALSA dev.
        let _id = req.into_inner().id;
        // Allow override (`LESAVKA_ALSA_DEV=hw:2,0` for debugging).
        let dev = std::env::var("LESAVKA_ALSA_DEV").unwrap_or_else(|_| "hw:UAC2Gadget,0".into());
        info!(rpc_id, %dev, "🔊 capture_audio opened");

        let s = audio::ear(&dev, 0)
            .await
            .map_err(|e| Status::internal(format!("{e:#}")))?;

        Ok(Response::new(Box::pin(s)))
    }

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

    /*────────────── USB-reset RPC ────────────*/
    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
    }
}

#[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, &pkt.data).await;
                tx.send(Ok(pkt)).await.ok();
                if !report_delay.is_zero() {
                    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, &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> {
        Err(Status::internal(
            "microphone sink unavailable in coverage harness",
        ))
    }

    async fn stream_camera(
        &self,
        _req: Request<tonic::Streaming<VideoPacket>>,
    ) -> Result<Response<Self::StreamCameraStream>, Status> {
        Err(Status::internal(
            "camera stream unavailable in coverage harness",
        ))
    }

    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
    }
}

/*──────────────── main ───────────────────────*/
#[cfg(not(coverage))]
#[tokio::main(worker_threads = 4)]
async fn main() -> anyhow::Result<()> {
    let _guard = init_tracing()?;
    info!("🚀 {} v{} starting up", PKG_NAME, lesavka_server::VERSION);

    panic::set_hook(Box::new(|p| {
        let bt = Backtrace::force_capture();
        error!("💥 panic: {p}\n{bt}");
    }));

    let gadget = UsbGadget::new("lesavka");
    if std::env::var("LESAVKA_DISABLE_UVC").is_err() {
        if std::env::var("LESAVKA_UVC_EXTERNAL").is_ok() {
            info!("📷 UVC control helper external; not spawning");
        } else {
            let bin = uvc_runtime::uvc_ctrl_bin();
            tokio::spawn(uvc_runtime::supervise_uvc_control(bin));
        }
    } else {
        info!("📷 UVC disabled (LESAVKA_DISABLE_UVC set)");
    }
    let handler = Handler::new(gadget.clone()).await?;

    info!("🌐 lesavka-server listening on 0.0.0.0:50051");
    Server::builder()
        .tcp_nodelay(true)
        .max_frame_size(Some(2 * 1024 * 1024))
        .add_service(RelayServer::new(handler))
        .add_service(HandshakeSvc::server())
        .add_service(ReflBuilder::configure().build_v1().unwrap())
        .serve(([0, 0, 0, 0], 50051).into())
        .await?;
    Ok(())
}

#[cfg(coverage)]
#[tokio::main(worker_threads = 2)]
async fn main() -> anyhow::Result<()> {
    let gadget = UsbGadget::new("lesavka");
    let _handler = Handler::new(gadget).await?;
    Err(anyhow::anyhow!("coverage mode skips live gRPC serve loop"))
}