helix-driver-host 0.1.2

//! Shared HTTP and WebSocket clients for PC Tauri and Flutter FFI.
//!
//! Login/auth remains outside Helix. Platform shells provide config and update
//! headers; these clients only inject the latest header snapshot into requests.

use std::sync::Arc;
use std::time::Duration;

use bytes::Bytes;
use futures_util::{SinkExt, StreamExt};
use helix_core::effect::TransportId;
use helix_core::ports::FrameSender;
use helix_core::tick::InboundBytes;
use helix_core::{PortError, Tick};
use reqwest::header::USER_AGENT;
use tokio::sync::{mpsc, oneshot, watch, Mutex};
use tokio_tungstenite::tungstenite::client::IntoClientRequest;
use tokio_tungstenite::tungstenite::Message;

use crate::metrics::{
    AsyncMetricSink, LabelKey, MetricEvent, MetricId, MetricLabels, NoopMetricSink,
};
use crate::tick_ingress::TickIngressSender;
use crate::trace::TraceCarrier;

// URL/header 工具裂分到 sibling（按职责，structure-gate §1）。`use *` 复用 6 个 pub(super) helper。
#[path = "network_util.rs"]
mod network_util;
use network_util::{header_value, headers_to_strings, map_ws_err, validate_url};

mod config;
pub use config::{HostHeaderRegistry, HostNetworkConfig};

mod http;
pub use http::{PreparedHttpRequest, SharedHttpClient};

const WS_FRAME_BUFFER: usize = 64;

#[derive(Clone)]
pub(crate) enum InboundTickSender {
    Raw(mpsc::Sender<Tick>),
    Stamped(TickIngressSender),
}

impl InboundTickSender {
    async fn send(&self, tick: Tick) -> Result<(), Tick> {
        self.send_with_trace(tick, None).await
    }

    /// 将 WS envelope 中提取的 carrier 与入站 Tick 一起送入 stamped ingress。
    async fn send_with_trace(&self, tick: Tick, carrier: Option<TraceCarrier>) -> Result<(), Tick> {
        match self {
            Self::Raw(tx) => tx.send(tick).await.map_err(|error| error.0),
            Self::Stamped(tx) => tx.send_with_trace(tick, carrier).await,
        }
    }
}

type WsSink = futures_util::stream::SplitSink<
    tokio_tungstenite::WebSocketStream<tokio_tungstenite::MaybeTlsStream<tokio::net::TcpStream>>,
    Message,
>;

#[derive(Clone, Copy, Debug, PartialEq, Eq)]
enum WsLifecyclePhase {
    Prepared,
    Active,
    Finished,
}

pub(crate) struct WsConnectionLifecycle {
    phase: Mutex<WsLifecyclePhase>,
    inbound: Option<(TransportId, InboundTickSender)>,
}

impl WsConnectionLifecycle {
    pub(crate) fn new(inbound: Option<(TransportId, InboundTickSender)>) -> Self {
        Self {
            phase: Mutex::new(WsLifecyclePhase::Prepared),
            inbound,
        }
    }

    pub(crate) async fn activate(&self) -> Result<bool, PortError> {
        let mut phase = self.phase.lock().await;
        if *phase != WsLifecyclePhase::Prepared {
            return Ok(false);
        }

        if let Some((id, tick_tx)) = &self.inbound {
            tick_tx
                .send(Tick::Connected(*id))
                .await
                .map_err(|_| PortError::Transport("lifecycle tick channel closed".to_string()))?;
        }
        *phase = WsLifecyclePhase::Active;
        Ok(true)
    }

    pub(crate) async fn finish_once(&self) {
        let mut phase = self.phase.lock().await;
        match *phase {
            WsLifecyclePhase::Prepared => {
                *phase = WsLifecyclePhase::Finished;
            }
            WsLifecyclePhase::Active => {
                if let Some((id, tick_tx)) = &self.inbound {
                    tick_tx.send(Tick::Disconnected(*id)).await.ok();
                }
                // send 被取消时仍保留 Active，让 reader/cleanup 中的另一方能够重试；
                // await 成功或明确失败后才封口，避免永久吞掉唯一一次 Disconnected。
                *phase = WsLifecyclePhase::Finished;
            }
            WsLifecyclePhase::Finished => {}
        }
    }
}

/// 一次物理 WS 连接的发布令牌。
///
/// `connect()` 只完成握手并让 sender 可用；调用方必须先把 sender 注册进路由表，再消费本令牌。
/// 激活严格执行 `Connected` 入队后才放行 reader，令牌被丢弃时 reader 静默退出。
#[must_use = "sender 注册完成后必须调用 activate，才能发布 Connected 并放行 reader"]
pub struct WsConnectionActivation {
    reader_gate: oneshot::Sender<()>,
    lifecycle: Arc<WsConnectionLifecycle>,
}

impl WsConnectionActivation {
    pub async fn activate(self) -> Result<(), PortError> {
        if !self.lifecycle.activate().await? {
            return Ok(());
        }

        self.reader_gate
            .send(())
            .map_err(|_| PortError::Transport("websocket reader stopped before activation".into()))
    }
}

struct WsCloseCompletion {
    result: watch::Sender<Option<Result<(), String>>>,
}

impl WsCloseCompletion {
    fn new() -> Self {
        let (result, _) = watch::channel(None);
        Self { result }
    }

    fn complete(&self, result: Result<(), String>) {
        self.result.send_replace(Some(result));
    }

    async fn wait(&self) -> Result<(), PortError> {
        let mut result_rx = self.result.subscribe();
        loop {
            let result = result_rx.borrow().clone();
            if let Some(result) = result {
                return result.map_err(PortError::Transport);
            }
            result_rx.changed().await.map_err(|_| {
                PortError::Transport("websocket cleanup completion channel closed".to_string())
            })?;
        }
    }
}

enum WsState {
    Disconnected,
    Closing {
        completion: Arc<WsCloseCompletion>,
    },
    Connected {
        sink: WsSink,
        frame_rx: mpsc::Receiver<Result<Bytes, PortError>>,
        reader: tokio::task::JoinHandle<()>,
        lifecycle: Arc<WsConnectionLifecycle>,
    },
}

/// Shared tokio-tungstenite-backed WebSocket port implementation.
///
/// 入站读任务有两条路径（按是否注入 `inbound`）：
/// - **push（native/FFI engine_loop）**：注入 `(id, tick_tx)` → 读任务把数据帧作 `Tick::Inbound`
///   直接喂泵，连接关闭/出错作 `Tick::Disconnected`。生产 engine_loop 从不调 `recv()`，
///   入站全靠此通道（A2，HX 入站不变量）。读任务独立持 stream 半边，不碰 send 锁。
/// - **pull（兼容 / 单测）**：无 `inbound` → 读任务塞内部 `frame_rx`，由平台生命周期 API 拉取。
pub struct SharedWsClient {
    config: HostNetworkConfig,
    headers: HostHeaderRegistry,
    state: Arc<Mutex<WsState>>,
    /// 可选入站推送通道：Some 时 shared lifecycle 发 Connected/Disconnected，reader 发 Inbound。
    inbound: Option<(TransportId, InboundTickSender)>,
    metrics: Arc<dyn AsyncMetricSink>,
}

impl SharedWsClient {
    pub fn new(config: HostNetworkConfig) -> Result<Self, PortError> {
        Self::with_registry(config, HostHeaderRegistry::default())
    }

    pub fn with_registry(
        config: HostNetworkConfig,
        headers: HostHeaderRegistry,
    ) -> Result<Self, PortError> {
        validate_url(&config.ws_url, "ws_url")?;
        Ok(Self {
            config,
            headers,
            state: Arc::new(Mutex::new(WsState::Disconnected)),
            inbound: None,
            metrics: Arc::new(NoopMetricSink),
        })
    }

    pub fn headers(&self) -> HostHeaderRegistry {
        self.headers.clone()
    }

    /// 注入入站推送通道（native/FFI engine_loop 路径，A2）。
    ///
    /// 设置后，connect 的读任务把数据帧作 `Tick::Inbound` 直发 `tick_tx`、
    /// 连接关闭/出错作 `Tick::Disconnected(id)`，而非塞内部 `frame_rx`。
    pub fn with_inbound_tick(mut self, id: TransportId, tick_tx: mpsc::Sender<Tick>) -> Self {
        self.inbound = Some((id, InboundTickSender::Raw(tick_tx)));
        self
    }

    pub fn with_stamped_inbound_tick(
        mut self,
        id: TransportId,
        tick_tx: TickIngressSender,
    ) -> Self {
        self.inbound = Some((id, InboundTickSender::Stamped(tick_tx)));
        self
    }

    pub fn with_metric_sink(mut self, metrics: Arc<dyn AsyncMetricSink>) -> Self {
        self.metrics = metrics;
        self
    }
}

impl SharedWsClient {
    /// 完成物理握手，但保持 reader 暂停。
    ///
    /// 返回的 activation 必须在 sender 已进入平台路由表后消费；这样业务处理
    /// `Tick::Connected` 时，`Effect::Send` 一定能命中当前连接。
    pub async fn connect(&mut self) -> Result<WsConnectionActivation, PortError> {
        let is_disconnected = {
            let state = self.state.lock().await;
            matches!(&*state, WsState::Disconnected)
        };
        if !is_disconnected {
            return Err(PortError::Transport(
                "connect on active or closing transport".to_string(),
            ));
        }

        let mut request = self
            .config
            .ws_url
            .as_str()
            .into_client_request()
            .map_err(|e| PortError::Transport(format!("invalid ws request: {e}")))?;
        for (name, value) in self.headers.snapshot().await.iter() {
            request.headers_mut().insert(name.clone(), value.clone());
        }
        if let Some(user_agent) = &self.config.user_agent {
            request
                .headers_mut()
                .insert(USER_AGENT, header_value("user-agent", user_agent)?);
        }
        let handshake_headers = headers_to_strings(request.headers());
        crate::network_debug::dump_ws_handshake(&self.config.ws_url, &handshake_headers);

        let (ws, _resp) = tokio_tungstenite::connect_async(request)
            .await
            .map_err(map_ws_err)?;
        let (sink, mut stream) = ws.split();
        let (frame_tx, frame_rx) = mpsc::channel::<Result<Bytes, PortError>>(WS_FRAME_BUFFER);
        let (reader_gate, reader_gate_rx) = oneshot::channel();
        let (reader_ready_tx, reader_ready_rx) = oneshot::channel();

        // 联调工具：HELIX_DUMP_FRAMES 置位时打印每条入站原始帧（抓真 Go wire 做 golden fixtures）。
        let dump_frames = std::env::var("HELIX_DUMP_FRAMES").is_ok();
        let inbound = self.inbound.clone();
        let metrics = Arc::clone(&self.metrics);
        let lifecycle = Arc::new(WsConnectionLifecycle::new(inbound.clone()));
        let reader_lifecycle = Arc::clone(&lifecycle);

        let reader = tokio::spawn(async move {
            reader_ready_tx.send(()).ok();
            if reader_gate_rx.await.is_err() {
                return;
            }

            while let Some(msg) = stream.next().await {
                // 归一化数据帧字节（Binary/Text 统一 Bytes）；关闭/出错单独处理。
                let frame = match msg {
                    Ok(Message::Binary(data)) => Ok(Bytes::from(data)),
                    Ok(Message::Text(text)) => Ok(Bytes::from(text.into_bytes())),
                    Ok(Message::Close(_)) => break,
                    Ok(Message::Ping(_)) | Ok(Message::Pong(_)) | Ok(Message::Frame(_)) => continue,
                    Err(e) => Err(map_ws_err(e)),
                };

                if dump_frames {
                    if let Ok(bytes) = &frame {
                        tracing::info!(
                            target: "helix_ws_frames",
                            len = bytes.len(),
                            frame = %String::from_utf8_lossy(bytes),
                            "RAW WS inbound"
                        );
                    }
                }
                if let Ok(bytes) = &frame {
                    crate::network_debug::dump_ws_inbound(bytes);
                    if metrics.is_enabled() {
                        let _ = metrics.try_record(MetricEvent::counter(
                            MetricId::OperationsTotal,
                            1.0,
                            MetricLabels::one(LabelKey::Stage, "ws")
                                .with(LabelKey::Protocol, "ws")
                                .with(LabelKey::Direction, "inbound")
                                .with(LabelKey::Status, "ok"),
                        ));
                    }
                }

                match &inbound {
                    // push 路径（native engine_loop）：数据帧 → Tick::Inbound 直发泵。
                    // 读任务独立持 stream 半边、不碰 send 锁，故不与 send 抢锁（A2）。
                    Some((_, tick_tx)) => match frame {
                        Ok(bytes) => {
                            let carrier = TraceCarrier::from_ws_frame(&bytes);
                            if tick_tx
                                .send_with_trace(Tick::Inbound(InboundBytes(bytes)), carrier)
                                .await
                                .is_err()
                            {
                                break; // 泵已关闭
                            }
                        }
                        // 入站读出错（如非法帧）：视为连接异常，下面 loop 退出补 Disconnected。
                        Err(_) => break,
                    },
                    // pull 路径（无 inbound bridge 的兼容/单测）：塞 frame_rx 供 recv 拉取。
                    None => {
                        if frame_tx.send(frame).await.is_err() {
                            break; // 接收端已关闭
                        }
                    }
                }
            }

            // reader 与显式 close 共用同一个每连接 lifecycle，远端/本地竞速也只发布一次。
            reader_lifecycle.finish_once().await;
        });

        if reader_ready_rx.await.is_err() {
            reader.abort();
            return Err(PortError::Transport(
                "websocket reader stopped before reaching activation gate".to_string(),
            ));
        }

        *self.state.lock().await = WsState::Connected {
            sink,
            frame_rx,
            reader,
            lifecycle: Arc::clone(&lifecycle),
        };
        Ok(WsConnectionActivation {
            reader_gate,
            lifecycle,
        })
    }

    /// 发送一帧（Text/JSON 消息）。
    ///
    /// 现网 Go 按 WS 帧类型选 codec：**Text→JSON 解码，Binary→msgpack 解码**。
    /// helix 出站帧是 JSON（hello/ping/业务），必须发 **Text**——发 Binary 则 Go 用 msgpack
    /// 解 `{`(0x7b) 失败：`msgpack: unexpected code=7b decoding map length` → 关连接
    /// （真 Go dev-loop 三测实测定位的 ~8s 断连根因，c823701）。双端（PC+Flutter）共享此修。
    async fn send_frame(&self, frame: Bytes) -> Result<(), PortError> {
        crate::network_debug::dump_ws_outbound(&frame);
        let mut state = self.state.lock().await;
        let result = match &mut *state {
            WsState::Connected { sink, .. } => {
                let text = String::from_utf8(frame.to_vec())
                    .map_err(|e| PortError::Transport(format!("non-utf8 ws frame: {e}")))?;
                sink.send(Message::Text(text)).await.map_err(map_ws_err)
            }
            WsState::Disconnected => Err(PortError::Transport(
                "send on disconnected transport".to_string(),
            )),
            WsState::Closing { .. } => Err(PortError::Transport(
                "send on closing transport".to_string(),
            )),
        };
        drop(state);
        if self.metrics.is_enabled() {
            let status = if result.is_ok() { "ok" } else { "error" };
            let labels = MetricLabels::one(LabelKey::Stage, "ws")
                .with(LabelKey::Protocol, "ws")
                .with(LabelKey::Direction, "outbound")
                .with(LabelKey::Status, status);
            let _ = self.metrics.try_record(MetricEvent::counter(
                MetricId::OperationsTotal,
                1.0,
                labels,
            ));
            if result.is_err() {
                let _ = self.metrics.try_record(MetricEvent::counter(
                    MetricId::ErrorsTotal,
                    1.0,
                    labels.with(LabelKey::ErrorKind, "ws_send_failed"),
                ));
            }
        }
        result
    }

    pub async fn recv(&self) -> Result<Option<Bytes>, PortError> {
        let mut state = self.state.lock().await;
        match &mut *state {
            WsState::Connected { frame_rx, .. } => match frame_rx.recv().await {
                Some(Ok(bytes)) => Ok(Some(bytes)),
                Some(Err(e)) => Err(e),
                None => Ok(None),
            },
            WsState::Disconnected | WsState::Closing { .. } => Ok(None),
        }
    }

    pub async fn close(&self) -> Result<(), PortError> {
        enum CloseAction {
            Done,
            Wait(Arc<WsCloseCompletion>),
            Start {
                sink: WsSink,
                reader: tokio::task::JoinHandle<()>,
                lifecycle: Arc<WsConnectionLifecycle>,
                completion: Arc<WsCloseCompletion>,
                close_timeout: Duration,
            },
        }

        let action = {
            let mut state = self.state.lock().await;
            match std::mem::replace(&mut *state, WsState::Disconnected) {
                WsState::Disconnected => CloseAction::Done,
                WsState::Closing { completion } => {
                    *state = WsState::Closing {
                        completion: Arc::clone(&completion),
                    };
                    CloseAction::Wait(completion)
                }
                WsState::Connected {
                    sink,
                    reader,
                    lifecycle,
                    ..
                } => {
                    let completion = Arc::new(WsCloseCompletion::new());
                    *state = WsState::Closing {
                        completion: Arc::clone(&completion),
                    };
                    CloseAction::Start {
                        sink,
                        reader,
                        lifecycle,
                        completion,
                        close_timeout: self.config.timeout,
                    }
                }
            }
        };

        match action {
            CloseAction::Done => Ok(()),
            CloseAction::Wait(completion) => completion.wait().await,
            CloseAction::Start {
                mut sink,
                reader,
                lifecycle,
                completion,
                close_timeout,
            } => {
                let state = Arc::clone(&self.state);
                let completion_for_cleanup = Arc::clone(&completion);
                let cleanup = tokio::spawn(async move {
                    // 清理任务独立于 close 调用方；调用方 future 被取消时，任务仍持有 reader
                    // 和 sink，并最终发布 lifecycle、回收 reader、落稳 Disconnected。
                    let close_result =
                        match tokio::time::timeout(close_timeout, sink.send(Message::Close(None)))
                            .await
                        {
                            Ok(result) => result.map_err(|error| error.to_string()),
                            Err(_) => Err(format!(
                                "websocket Close write timed out after {}ms",
                                close_timeout.as_millis()
                            )),
                        };
                    reader.abort();
                    // abort 只是发出取消信号；必须等待 reader 真正退出，才能保证不会在
                    // Disconnected 之后尾随一条正在并发处理的 Inbound。
                    let _ = reader.await;
                    lifecycle.finish_once().await;
                    let mut state = state.lock().await;
                    completion_for_cleanup.complete(close_result);
                    *state = WsState::Disconnected;
                });

                cleanup.await.map_err(|error| {
                    PortError::Transport(format!("websocket cleanup task failed: {error}"))
                })?;
                // 已进入 Closing 的 waiter 读取同一结果；状态落稳后的 close 按幂等语义返回 Ok。
                completion.wait().await
            }
        }
    }
}

#[async_trait::async_trait]
impl FrameSender for SharedWsClient {
    async fn send(&self, frame: Bytes) -> Result<(), PortError> {
        self.send_frame(frame).await
    }
}