nautilus_live/node/

mod.rs

// -------------------------------------------------------------------------------------------------
//  Copyright (C) 2015-2026 Nautech Systems Pty Ltd. All rights reserved.
//  https://nautechsystems.io
//
//  Licensed under the GNU Lesser General Public License Version 3.0 (the "License");
//  You may not use this file except in compliance with the License.
//  You may obtain a copy of the License at https://www.gnu.org/licenses/lgpl-3.0.en.html
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.
// -------------------------------------------------------------------------------------------------

//! Live trading node built on a single-threaded tokio event loop.
//!
//! `LiveNode::run()` drives the system through a `tokio::select!` loop that
//! multiplexes data events, execution events, trading commands, timers, and
//! periodic maintenance tasks (reconciliation, purge, prune, audit).
//!
//! # Threading model
//!
//! The core types (`ExecutionManager`, `ExecutionEngine`, `Cache`) use
//! `Rc<RefCell<..>>` and are `!Send`. All access happens on the same thread.
//! The `select!` macro runs one branch to completion (including inner awaits)
//! before polling the next, so `RefCell` borrows held across `.await` points
//! within a single branch cannot conflict with borrows in other branches.
//!
//! # Startup sequencing
//!
//! Startup connects clients in two phases so that instruments are in the
//! cache before execution clients read them:
//!
//! 1. Connect data clients (instruments arrive as buffered `DataEvent`s).
//! 2. Flush all pending data events and commands into the cache via
//!    `flush_pending_data`, which loops `try_recv` on the channel receivers
//!    until no items remain.
//! 3. Connect execution clients (`load_instruments_from_cache` now finds
//!    populated instruments).
//! 4. Drain remaining events, then run reconciliation.
//!
//! Both `run()` (integrated event loop) and `start()` (manual lifecycle)
//! follow this sequence.
//!
//! # Reconciliation
//!
//! Continuous inflight and open-order checks run on independent intervals. The
//! shared maintenance timer in the select loop dispatches reconciliation at
//! the minimum enabled interval. Each dispatch the handler checks which
//! sub-checks are due based on elapsed nanoseconds and schedules their work.
//! Continuous checks do not await venue HTTP in the select loop: open-order
//! and position checks poll bulk venue report futures from the loop.
//!
//! # Maintenance dispatcher
//!
//! Six periodic tasks share a single coarse `maintenance_timer`:
//!
//! - reconciliation (inflight, open, position sub-checks)
//! - purge closed orders
//! - purge closed positions
//! - purge account events
//! - own-books audit
//! - recent-fills cache prune
//!
//! The runner wakes one timer per loop iteration regardless of how many
//! maintenance tasks are configured. Each task tracks its own
//! `next_fire: Instant` and the dispatcher fires the bodies whose deadline
//! has passed, rescheduling `next = now + interval` (equivalent to
//! `MissedTickBehavior::Delay`). Disabled tasks anchor on a far-future
//! `next` that never trips.
//!
//! The 100ms timer cadence is the effective floor for any maintenance
//! interval. Configured intervals below 100ms (the config types allow
//! `inflight_check_interval_ms` and `own_books_audit_interval_secs` smaller)
//! get rounded up to the next tick. Real workloads do not run venue or cache
//! maintenance below 100ms (defaults are seconds to minutes). Cadence drifts
//! by at most one body duration per fire.

use std::{collections::HashSet, fmt::Debug, future::Future, pin::Pin, time::Duration};

use anyhow::Context;
use indexmap::IndexSet;
use nautilus_common::{
    actor::{Actor, DataActor, DataActorNative},
    cache::database::{CacheDatabaseAdapter, CacheDatabaseFactory},
    clients::ExecutionClient,
    component::Component,
    enums::{Environment, LogColor},
    live::dst,
    log_info,
    messages::{
        DataEvent, ExecutionEvent, ExecutionReport, SystemCommand, SystemEvent,
        data::DataCommand,
        execution::{GenerateOrderStatusReports, GeneratePositionStatusReports, TradingCommand},
        system::{QueueStateChanged, SocketStateChange, SocketStateChanged},
    },
    msgbus::{self, BusMessage, MessagingSwitchboard},
    runner::{SystemChannel, TimeEventMessage, TradingCommandMessage},
};
use nautilus_core::{
    UUID4,
    datetime::{NANOSECONDS_IN_MILLISECOND, mins_to_secs, secs_to_nanos_unchecked},
};
use nautilus_execution::engine::ExecutionEngine;
#[cfg(test)]
use nautilus_model::reports::OrderStatusReport;
use nautilus_model::{
    events::OrderEventAny,
    identifiers::{ClientId, ClientOrderId, InstrumentId, StrategyId, TraderId},
    orders::Order,
    reports::PositionStatusReport,
};
#[cfg(feature = "python")]
use nautilus_system::trader::Trader;
use nautilus_system::{config::NautilusKernelConfig, kernel::NautilusKernel};
use nautilus_trading::{
    ExecutionAlgorithm, ExecutionAlgorithmNative,
    strategy::{Strategy, StrategyNative},
};
use tabled::{builder::Builder, settings::Style};

use crate::{
    execution::{
        client::LiveExecutionClient,
        manager::{
            ExecutionManager, ExecutionManagerConfig, OpenOrderReportCheck, PositionReportCheck,
            SourcedOrderStatusReport, TargetedOrderQuery, TargetedOrderReportResult,
            request_targeted_order_reports,
        },
    },
    runner::{AsyncRunner, AsyncRunnerChannels, PendingRunnerEvent},
};

pub mod builder;
pub mod config;

#[cfg(feature = "plugin")]
pub mod plugin;

mod metrics;
mod queue;
mod state;

use builder::ExternalMessageBusIngress;
pub use builder::LiveNodeBuilder;
use config::{LiveNodeConfig, PluginConfig, validate_live_environment};
pub use metrics::{RunnerChannelMetricsSnapshot, RunnerMetricsDelta, RunnerMetricsSnapshot};
use metrics::{RunnerChannelQueueDepths, RunnerMetrics};
use queue::{QueueMonitor, QueueStateTransition};
use state::{EngineConnectionStatus, RunningTransition};
pub use state::{LiveNodeHandle, NodeRunMode, NodeState};

/// Dispatches the run loop performs before yielding to the executor.
///
/// A saturated channel keeps every select branch ready, so the loop would otherwise never return
/// `Pending`. Under a host event loop that starves the adapter I/O tasks feeding those channels,
/// which shows up as lapsed heartbeats and reconnects rather than as backpressure.
const DISPATCHES_PER_YIELD: usize = 64;

/// High-level abstraction for a live Nautilus system node.
///
/// Provides a simplified interface for running live systems
/// with automatic client management and lifecycle handling.
#[derive(Debug)]
pub struct LiveNode {
    kernel: NautilusKernel,
    runner: Option<AsyncRunner>,
    config: LiveNodeConfig,
    handle: LiveNodeHandle,
    exec_manager: ExecutionManager,
    exec_clients: Vec<LiveExecutionClient>,
    cache_database_factory: Option<Box<dyn CacheDatabaseFactory>>,
    external_msgbus: Option<ExternalMessageBusIngress>,
    shutdown_deadline: Option<dst::time::Instant>,
    #[cfg(feature = "plugin")]
    plugins: plugin::NodePlugins,
}

impl LiveNode {
    /// Creates a new `LiveNode` from builder components.
    ///
    /// This is an internal constructor used by `LiveNodeBuilder`.
    #[must_use]
    pub(crate) fn new_from_builder(
        kernel: NautilusKernel,
        runner: AsyncRunner,
        config: LiveNodeConfig,
        exec_manager: ExecutionManager,
        exec_clients: Vec<LiveExecutionClient>,
        cache_database_factory: Option<Box<dyn CacheDatabaseFactory>>,
        external_msgbus: Option<ExternalMessageBusIngress>,
    ) -> Self {
        Self {
            kernel,
            runner: Some(runner),
            config,
            handle: LiveNodeHandle::new(),
            exec_manager,
            exec_clients,
            cache_database_factory,
            external_msgbus,
            shutdown_deadline: None,
            #[cfg(feature = "plugin")]
            plugins: plugin::NodePlugins,
        }
    }

    /// Creates a new [`LiveNodeBuilder`] for fluent configuration.
    ///
    /// # Errors
    ///
    /// Returns an error if the environment is invalid for live trading.
    pub fn builder(
        trader_id: TraderId,
        environment: Environment,
    ) -> anyhow::Result<LiveNodeBuilder> {
        LiveNodeBuilder::new(trader_id, environment)
    }

    /// Creates a new [`LiveNode`] directly from a kernel name and optional configuration.
    ///
    /// This is a convenience method for creating a live node with a pre-configured
    /// kernel configuration, bypassing the builder pattern. If no config is provided,
    /// a default configuration will be used.
    ///
    /// # Errors
    ///
    /// Returns an error if kernel construction fails.
    pub fn build(name: String, config: Option<LiveNodeConfig>) -> anyhow::Result<Self> {
        let config = config.unwrap_or_default();
        validate_live_environment(config.environment())?;

        config.validate_runtime_support()?;

        if config.event_store.is_some() {
            anyhow::bail!(
                "LiveNodeConfig.event_store is set but LiveNode::build cannot install a factory; \
                 use LiveNodeBuilder::with_event_store(...) instead"
            );
        }

        let runner = AsyncRunner::new();
        runner.bind_senders();

        let kernel = NautilusKernel::new(name, config.clone())?;
        #[cfg(feature = "python")]
        if let Some(controller) = config.controller.as_ref() {
            Trader::add_controller_from_importable_config(&kernel.trader, controller)?;
        }
        #[cfg(not(feature = "python"))]
        if let Some(controller) = config.controller.as_ref() {
            anyhow::bail!(
                "LiveNodeConfig.controller for importable controller '{}' requires the python feature",
                controller.controller_path
            );
        }

        let exec_manager_config =
            ExecutionManagerConfig::from(&config.exec_engine).with_trader_id(config.trader_id);
        let exec_manager = ExecutionManager::new(
            kernel.clock.clone(),
            kernel.cache.clone(),
            exec_manager_config,
        );

        let node = Self {
            kernel,
            runner: Some(runner),
            config,
            handle: LiveNodeHandle::new(),
            exec_manager,
            exec_clients: Vec::new(),
            cache_database_factory: None,
            external_msgbus: None,
            shutdown_deadline: None,
            #[cfg(feature = "plugin")]
            plugins: plugin::NodePlugins,
        };
        node.load_configured_plugins()?;

        log::info!("LiveNode built successfully with kernel config");

        Ok(node)
    }

    /// Loads and registers plug-ins declared on the node config.
    ///
    /// # Errors
    ///
    /// Returns an error when plug-ins are configured without host-side support.
    pub(crate) fn load_configured_plugins(&self) -> anyhow::Result<()> {
        if self.config.plugins.is_empty() {
            return Ok(());
        }

        anyhow::bail!(
            "LiveNodeConfig.plugins requires host-side plug-in support; nautilus-plugin is the guest SDK only"
        )
    }

    /// Loads and registers one plug-in instance.
    ///
    /// # Errors
    ///
    /// Returns an error because dynamic plug-in hosting lives in the host-side integration.
    #[expect(
        clippy::needless_pass_by_value,
        reason = "signature mirrors the host-enabled API"
    )]
    pub fn add_plugin(&mut self, config: PluginConfig) -> anyhow::Result<()> {
        #[cfg(feature = "plugin")]
        config.validate_runtime_support(self.config.plugins.len())?;
        #[cfg(not(feature = "plugin"))]
        let _ = config;

        anyhow::bail!(
            "LiveNode::add_plugin requires host-side plug-in support; nautilus-plugin is the guest SDK only"
        )
    }

    /// Returns a thread-safe handle to control this node.
    #[must_use]
    pub fn handle(&self) -> LiveNodeHandle {
        self.handle.clone()
    }

    /// Starts the live node without entering a select loop.
    ///
    /// Connects clients, runs reconciliation, and starts the trader, but does
    /// not consume the runner or drive channel receivers, so channel traffic arriving after
    /// startup is never serviced. This is a building block for tests and embedding, not a
    /// lifecycle: use [`run`](Self::run) or [`run_with_mode`](Self::run_with_mode) to run a node.
    ///
    /// # Errors
    ///
    /// Returns an error if startup fails.
    pub async fn start(&mut self) -> anyhow::Result<()> {
        if self.state().is_running() {
            anyhow::bail!("Already running");
        }

        if self.external_msgbus.is_some() {
            log::warn!(
                "External message bus ingress is configured but LiveNode::start() does not service it; use LiveNode::run()"
            );
        }

        self.prepare_cache().await?;

        if let Some(runner) = self.runner.as_ref() {
            runner.bind_senders();
        }

        self.handle.set_starting();

        self.kernel.reset_shutdown_flag();
        self.kernel.start_async().await;

        if self.kernel.is_event_store_replay() {
            log::info!(
                "Event-store replay loaded; skipping live client connection and reconciliation",
            );

            if !self.finish_startup_replay().await? {
                return Ok(());
            }
            return Ok(());
        }

        if self.kernel.is_event_store_replay_configured() {
            self.abort_startup("Event-store replay did not start")
                .await?;
            return Ok(());
        }

        let connection_deadline = dst::time::Instant::now() + self.config.timeout_connection;

        // Connect data clients first and flush instrument events into cache
        if let Err(e) = self.connect_data_phase(connection_deadline).await {
            return self
                .abort_startup_with_error("Data client connection timed out", e)
                .await;
        }

        let (startup_system_events, startup_system_commands) =
            if let Some(runner) = self.runner.as_mut() {
                runner.flush_pending_data();
                (
                    runner.drain_pending_system_events(),
                    runner.drain_pending_system_commands(),
                )
            } else {
                (Vec::new(), Vec::new())
            };

        if let Err(e) = self.connect_exec_clients(connection_deadline).await {
            return self
                .abort_startup_with_error("Execution client connection timed out", e)
                .await;
        }

        if let Some(reason) = self.startup_abort_reason() {
            self.abort_startup(reason).await?;
            return Ok(());
        }

        match self.await_engines_connected(connection_deadline).await {
            EngineConnectionStatus::Connected => {}
            EngineConnectionStatus::TimedOut => {
                return self
                    .abort_startup_with_error(
                        "Engine readiness timed out",
                        anyhow::anyhow!("readiness timeout while waiting for engine connections"),
                    )
                    .await;
            }
            EngineConnectionStatus::StopRequested => {
                self.abort_startup("Stop signal received during startup")
                    .await?;
                return Ok(());
            }
            EngineConnectionStatus::ShutdownRequested => {
                self.abort_startup("Shutdown signal received during startup")
                    .await?;
                return Ok(());
            }
        }

        if let Err(e) = self.perform_startup_reconciliation().await {
            if let Err(finalize_err) = self.abort_startup("Startup reconciliation failed").await {
                anyhow::bail!(
                    "startup reconciliation failed: {e}; failed to finalize startup abort: {finalize_err}"
                );
            }

            return Err(e);
        }

        if let Some(reason) = self.startup_abort_reason() {
            self.abort_startup(reason).await?;
            return Ok(());
        }

        if let Err(e) = self.kernel.start_trader() {
            return self.abort_after_trader_start_failure(e).await;
        }
        #[cfg(feature = "plugin")]
        if let Err(e) = self.plugins.start_controllers() {
            return self.abort_after_trader_start_failure(e).await;
        }

        self.process_system_events(startup_system_events);
        self.process_system_commands(startup_system_commands);

        if !self.finish_startup_trader(None).await? {
            return Ok(());
        }

        Ok(())
    }

    /// Stop the live node.
    ///
    /// This method stops the trader, waits for the configured grace period to allow
    /// residual events to be processed, then finalizes the shutdown sequence.
    ///
    /// # Errors
    ///
    /// Returns an error if shutdown fails.
    pub async fn stop(&mut self) -> anyhow::Result<()> {
        if !self.state().is_running() {
            anyhow::bail!("Not running");
        }

        self.handle.set_shutting_down();

        #[cfg(feature = "plugin")]
        let controller_stop_result = self.plugins.stop_controllers();
        #[cfg(not(feature = "plugin"))]
        let controller_stop_result: anyhow::Result<()> = Ok(());

        self.kernel.stop_trader();
        let delay = self.kernel.delay_post_stop();
        log::info!("Awaiting residual events ({delay:?})...");

        let residual_events = self.process_runner_for(delay).await;
        if residual_events > 0 {
            log::debug!("Processed {residual_events} residual events during shutdown");
        }

        let stop_result = self.finalize_stop().await;
        let drained_events = self.drain_runner_pending();
        if drained_events > 0 {
            log::info!("Drained {drained_events} remaining events during shutdown");
        }

        match (controller_stop_result, stop_result) {
            (Ok(()), Ok(())) => Ok(()),
            (Err(controller_err), Ok(())) => Err(controller_err),
            (Ok(()), Err(stop_err)) => Err(stop_err),
            (Err(controller_err), Err(stop_err)) => {
                log::error!("Error stopping plug-in controllers: {controller_err}");
                Err(stop_err)
            }
        }
    }

    /// Disposes the live node kernel and releases resources.
    pub fn dispose(&mut self) {
        self.close_external_ingress();
        self.kernel.dispose();
        self.handle.set_stopped();
    }

    async fn process_runner_for(&mut self, duration: Duration) -> usize {
        let Some(mut runner) = self.runner.take() else {
            dst::time::sleep(duration).await;
            return 0;
        };

        runner.bind_senders();
        let deadline = dst::time::Instant::now() + duration;
        let mut processed = 0;

        loop {
            tokio::select! {
                biased;

                () = dst::time::sleep_until(deadline) => break,
                event = runner.recv() => {
                    let Some(event) = event else {
                        dst::time::sleep_until(deadline).await;
                        break;
                    };

                    self.process_runner_event(event);
                    processed += 1;
                }
            }
        }

        self.runner = Some(runner);
        processed
    }

    fn drain_runner_pending(&mut self) -> usize {
        let Some(mut runner) = self.runner.take() else {
            return 0;
        };

        let processed = runner.poll_pending(|event| self.process_runner_event(event));
        self.runner = Some(runner);
        processed
    }

    fn process_runner_event(&mut self, event: PendingRunnerEvent) {
        match event {
            PendingRunnerEvent::TimeEvent(message) => {
                let _ = AsyncRunner::handle_time_event(message);
            }
            PendingRunnerEvent::SystemEvent(event) => self.process_system_event(event),
            PendingRunnerEvent::SystemCommand(command) => self.process_system_command(command),
            PendingRunnerEvent::ExecEvent(event) => self.process_exec_event(event),
            PendingRunnerEvent::ExecCommand(command) => self.process_exec_command(command),
            PendingRunnerEvent::DataEvent(event) => AsyncRunner::handle_data_event(event),
            PendingRunnerEvent::DataCommand(command) => AsyncRunner::handle_data_command(command),
        }
    }

    fn process_system_events(&self, events: Vec<SystemEvent>) {
        for event in events {
            self.process_system_event(event);
        }
    }

    fn process_system_commands(&self, commands: Vec<SystemCommand>) {
        for command in commands {
            self.process_system_command(command);
        }
    }

    fn process_system_command(&self, command: SystemCommand) {
        match command {
            SystemCommand::ReconnectSocket(command) => {
                self.kernel.process_socket_reconnect(command);
            }
        }
    }

    fn process_system_event(&self, event: SystemEvent) {
        match event {
            SystemEvent::SocketState(change) => self.publish_socket_state_change(change),
        }
    }

    fn publish_socket_state_change(&self, change: SocketStateChange) {
        let timestamp = self.kernel.generate_timestamp_ns();
        let event = SocketStateChanged::new(
            self.config.trader_id,
            change.client_id,
            change.venue,
            change.endpoint,
            change.state,
            UUID4::new(),
            timestamp,
            timestamp,
        );

        msgbus::publish_any(
            MessagingSwitchboard::socket_state_changed_topic(),
            event.as_any(),
        );
    }

    /// Awaits engine clients to connect with timeout.
    ///
    /// Returns the final connection wait status.
    async fn await_engines_connected(
        &self,
        deadline: dst::time::Instant,
    ) -> EngineConnectionStatus {
        log::info!(
            "Awaiting engine connections ({:?} timeout)...",
            self.config.timeout_connection
        );

        let interval = Duration::from_millis(100);

        loop {
            if self.handle.should_stop() {
                log::warn!("Stop signal received, aborting connection wait");
                return EngineConnectionStatus::StopRequested;
            }

            if self.kernel.is_shutdown_requested() {
                log::warn!("Shutdown signal received, aborting connection wait");
                return EngineConnectionStatus::ShutdownRequested;
            }

            if self.kernel.check_engines_connected() {
                log::info!("All engine clients connected");
                return EngineConnectionStatus::Connected;
            }

            let now = dst::time::Instant::now();
            if now >= deadline {
                break;
            }

            dst::time::sleep(interval.min(deadline - now)).await;
        }

        self.log_connection_status();
        EngineConnectionStatus::TimedOut
    }

    /// Awaits engine clients to disconnect with timeout.
    ///
    /// Returns an error with client status on timeout.
    async fn await_engines_disconnected(&self, deadline: dst::time::Instant) -> anyhow::Result<()> {
        log::info!(
            "Awaiting engine disconnections ({:?} timeout)...",
            self.config.timeout_disconnection
        );

        let timeout = self.config.timeout_disconnection;
        let interval = Duration::from_millis(100);

        loop {
            if self.kernel.check_engines_disconnected() {
                log::info!("All engine clients disconnected");
                return Ok(());
            }

            let now = dst::time::Instant::now();
            if now >= deadline {
                break;
            }

            dst::time::sleep(interval.min(deadline - now)).await;
        }

        log::error!(
            "Timed out ({:?}) waiting for engines to disconnect\n\
             DataEngine.check_disconnected() == {}\n\
             ExecEngine.check_disconnected() == {}",
            timeout,
            self.kernel.data_engine().check_disconnected(),
            self.kernel.exec_engine().borrow().check_disconnected(),
        );
        anyhow::bail!("disconnect readiness timeout while waiting for engine disconnections")
    }

    fn log_connection_status(&self) {
        let data_status = self.kernel.data_client_connection_status();
        let exec_status = self.kernel.exec_client_connection_status();

        let mut rows: Vec<ClientStatus> = Vec::new();

        for (client_id, connected) in data_status {
            rows.push(ClientStatus {
                client: client_id.to_string(),
                client_type: "Data",
                connected,
            });
        }

        for (client_id, connected) in exec_status {
            rows.push(ClientStatus {
                client: client_id.to_string(),
                client_type: "Execution",
                connected,
            });
        }

        let table = render_client_statuses(rows);

        log::warn!(
            "Timed out ({:?}) waiting for engines to connect\n\n{table}\n\n\
             DataEngine.check_connected() == {}\n\
             ExecEngine.check_connected() == {}",
            self.config.timeout_connection,
            self.kernel.data_engine().check_connected(),
            self.kernel.exec_engine().borrow().check_connected(),
        );
    }

    /// Performs startup reconciliation to align internal state with venue state.
    ///
    /// This method queries each execution client for mass status (orders, fills, positions)
    /// and reconciles any discrepancies with the local cache state.
    ///
    /// # Errors
    ///
    /// Returns an error if reconciliation fails or times out.
    #[expect(clippy::await_holding_refcell_ref)] // Single-threaded runtime, intentional design
    async fn perform_startup_reconciliation(&mut self) -> anyhow::Result<()> {
        if !self.config.exec_engine.reconciliation {
            log::info!("Startup reconciliation disabled");
            self.kernel
                .portfolio
                .borrow_mut()
                .initialize_wallet_orders()?;
            return Ok(());
        }

        log_info!(
            "Starting execution state reconciliation...",
            color = LogColor::Blue
        );

        let lookback_mins = self
            .config
            .exec_engine
            .reconciliation_lookback_mins
            .map(u64::from);

        let timeout = self.config.timeout_reconciliation;
        let start = dst::time::Instant::now();
        let client_ids = self.kernel.exec_engine.borrow().client_ids();

        for client_id in client_ids {
            let elapsed = start.elapsed();
            if elapsed >= timeout {
                anyhow::bail!("Startup reconciliation timeout reached");
            }
            let remaining = timeout
                .checked_sub(elapsed)
                .expect("elapsed checked against reconciliation timeout");

            log_info!(
                "Requesting mass status from {}...",
                client_id,
                color = LogColor::Blue
            );

            let mass_status_result = dst::time::timeout(remaining, async {
                self.kernel
                    .exec_engine
                    .borrow_mut()
                    .generate_mass_status(&client_id, lookback_mins)
                    .await
            })
            .await
            .map_err(|_| {
                anyhow::anyhow!(
                    "Startup reconciliation timeout reached while requesting mass status from {client_id}"
                )
            })?;

            match mass_status_result {
                Ok(Some(mass_status)) => {
                    log_info!(
                        "Reconciling ExecutionMassStatus for {}",
                        client_id,
                        color = LogColor::Blue
                    );

                    let exec_engine_rc = self.kernel.exec_engine.clone();

                    let result = self
                        .exec_manager
                        .reconcile_execution_mass_status(mass_status, exec_engine_rc)
                        .await;

                    anyhow::ensure!(
                        self.kernel
                            .exec_engine
                            .borrow()
                            .get_client(&client_id)
                            .is_some(),
                        "Execution client {client_id} disappeared during startup reconciliation",
                    );

                    if result.events.is_empty() {
                        log_info!(
                            "Reconciliation for {} succeeded",
                            client_id,
                            color = LogColor::Blue
                        );
                    } else {
                        log::info!(
                            color = LogColor::Blue as u8;
                            "Reconciliation for {} processed {} events",
                            client_id,
                            result.events.len()
                        );
                    }

                    // Register external orders with execution clients for tracking
                    if !result.external_orders.is_empty() {
                        let exec_engine = self.kernel.exec_engine.borrow();
                        let source_client = exec_engine.get_client(&client_id).ok_or_else(|| {
                            anyhow::anyhow!(
                                "Execution client {client_id} disappeared during startup reconciliation"
                            )
                        })?;

                        for external in result.external_orders {
                            source_client.register_external_order(
                                external.client_order_id,
                                external.venue_order_id,
                                external.instrument_id,
                                external.strategy_id,
                                external.ts_init,
                            );
                        }
                    }
                }
                Ok(None) => {
                    log::warn!(
                        "No mass status available from {client_id} \
                         (likely adapter error when generating reports)"
                    );
                }
                Err(e) => {
                    return Err(e).context(format!("Failed to get mass status from {client_id}"));
                }
            }
        }

        self.kernel.portfolio.borrow_mut().initialize_orders();
        self.kernel.portfolio.borrow_mut().initialize_positions();
        self.kernel
            .portfolio
            .borrow_mut()
            .initialize_wallet_orders()?;

        let elapsed_secs = start.elapsed().as_secs_f64();
        log_info!(
            "Startup reconciliation completed in {:.2}s",
            elapsed_secs,
            color = LogColor::Blue
        );

        Ok(())
    }

    /// Run the live node with automatic shutdown handling.
    ///
    /// This method starts the node, runs indefinitely, and handles graceful shutdown
    /// on interrupt signals.
    ///
    /// # Thread Safety
    ///
    /// The event loop runs directly on the current thread (not spawned) because the
    /// msgbus uses thread-local storage. Endpoints registered by the kernel are only
    /// accessible from the same thread.
    ///
    /// # Shutdown Sequence
    ///
    /// 1. Signal received (SIGINT, SIGTERM, or handle stop).
    /// 2. Trader components stopped (triggers order cancellations, etc.).
    /// 3. Event loop continues processing residual events for the configured grace period.
    /// 4. Kernel finalized, clients disconnected, remaining events drained.
    ///
    /// # Errors
    ///
    /// Returns an error if the node fails to start or encounters a runtime error.
    pub async fn run(&mut self) -> anyhow::Result<()> {
        self.run_with_mode(NodeRunMode::Owned).await
    }

    /// Run the live node under the given mode.
    ///
    /// [`NodeRunMode::Hosted`] leaves signal handling to the host application. Every other
    /// responsibility, including maintenance, reconciliation, external ingress, and the shutdown
    /// sequence, is identical across modes so that hosted and owned nodes cannot diverge.
    ///
    /// # Errors
    ///
    /// Returns an error if the node fails to start or encounters a runtime error.
    pub async fn run_with_mode(&mut self, mode: NodeRunMode) -> anyhow::Result<()> {
        if self.state().is_running() {
            anyhow::bail!("Already running");
        }

        if self.runner.is_none() {
            anyhow::bail!("Runner already consumed - run() called twice");
        }

        self.prepare_cache().await?;

        let Some(runner) = self.runner.take() else {
            anyhow::bail!("Runner already consumed - run() called twice");
        };
        runner.bind_senders();

        let AsyncRunnerChannels {
            mut time_evt_rx,
            mut system_evt_rx,
            mut system_cmd_rx,
            mut exec_evt_rx,
            mut exec_cmd_rx,
            mut data_evt_rx,
            mut data_cmd_rx,
        } = runner.take_channels();

        log::info!("Event loop starting");

        self.handle.set_starting();
        self.kernel.reset_shutdown_flag();
        self.kernel.start_async().await;

        if self.kernel.is_event_store_replay() {
            log::info!(
                "Event-store replay loaded; skipping live client connection and reconciliation",
            );

            if !self.finish_startup_replay().await? {
                return Ok(());
            }
            return Ok(());
        }

        if self.kernel.is_event_store_replay_configured() {
            self.abort_startup("Event-store replay did not start")
                .await?;
            return Ok(());
        }

        let mut external_msgbus_rx = match self.take_external_ingress_receiver() {
            Ok(rx) => rx,
            Err(e) => {
                let result = self
                    .abort_startup("External message bus ingress failed to start")
                    .await;
                Self::drain_channels(
                    &mut time_evt_rx,
                    &mut system_evt_rx,
                    &mut system_cmd_rx,
                    &mut exec_evt_rx,
                    &mut exec_cmd_rx,
                    &mut data_evt_rx,
                    &mut data_cmd_rx,
                );
                log::info!("Event loop stopped");

                if let Err(finalize_err) = result {
                    anyhow::bail!(
                        "failed to start external message bus ingress: {e}; failed to finalize startup abort: {finalize_err}"
                    );
                }

                return Err(e);
            }
        };

        let stop_handle = self.handle.clone();
        let mut pending = PendingEvents::default();
        let mut startup_system_events = Vec::new();
        let mut startup_system_commands = Vec::new();
        let connection_deadline = dst::time::Instant::now() + self.config.timeout_connection;

        // Startup phase 1: Connect data clients and drain instrument events into cache.
        // This ensures the cache is populated before execution clients connect.
        let data_connect_result = drive_with_event_buffering(
            self.connect_data_phase(connection_deadline),
            &mut pending,
            &mut time_evt_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        )
        .await;

        if let Err(e) = data_connect_result {
            flush_all_pending(
                &mut pending,
                &mut time_evt_rx,
                &mut system_evt_rx,
                &mut system_cmd_rx,
                &mut exec_evt_rx,
                &mut exec_cmd_rx,
                &mut data_evt_rx,
                &mut data_cmd_rx,
            );
            let result = self
                .abort_startup_with_error("Data client connection timed out", e)
                .await;
            Self::drain_channels(
                &mut time_evt_rx,
                &mut system_evt_rx,
                &mut system_cmd_rx,
                &mut exec_evt_rx,
                &mut exec_cmd_rx,
                &mut data_evt_rx,
                &mut data_cmd_rx,
            );
            log::info!("Event loop stopped");
            return result;
        }

        // Flush any data events still queued in the channel receivers that the
        // select loop did not capture before the connect future resolved, then
        // drain everything into cache.
        flush_pending_data(&mut pending, &mut data_evt_rx, &mut data_cmd_rx);
        startup_system_events.extend(pending.take_system_events());
        startup_system_commands.extend(pending.take_system_commands());
        debug_assert!(
            pending.data_evts.is_empty() && pending.data_cmds.is_empty(),
            "data must be drained into cache before exec clients connect",
        );

        // Startup phase 2: Connect execution clients (instruments now in cache)
        let engine_connection_result = drive_with_event_buffering(
            self.connect_exec_phase(connection_deadline),
            &mut pending,
            &mut time_evt_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        )
        .await;

        // Flush channel receivers and drain all remaining pending events
        flush_all_pending(
            &mut pending,
            &mut time_evt_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        );
        startup_system_events.extend(pending.take_system_events());
        startup_system_commands.extend(pending.take_system_commands());
        debug_assert!(
            pending.is_empty(),
            "all startup events must be processed before reconciliation",
        );

        let engine_connection_status = match engine_connection_result {
            Ok(status) => status,
            Err(e) => {
                let result = self
                    .abort_startup_with_error("Execution client connection timed out", e)
                    .await;
                Self::drain_channels(
                    &mut time_evt_rx,
                    &mut system_evt_rx,
                    &mut system_cmd_rx,
                    &mut exec_evt_rx,
                    &mut exec_cmd_rx,
                    &mut data_evt_rx,
                    &mut data_cmd_rx,
                );
                log::info!("Event loop stopped");
                return result;
            }
        };

        if engine_connection_status == EngineConnectionStatus::TimedOut {
            let result = self
                .abort_startup_with_error(
                    "Engine readiness timed out",
                    anyhow::anyhow!("readiness timeout while waiting for engine connections"),
                )
                .await;
            Self::drain_channels(
                &mut time_evt_rx,
                &mut system_evt_rx,
                &mut system_cmd_rx,
                &mut exec_evt_rx,
                &mut exec_cmd_rx,
                &mut data_evt_rx,
                &mut data_cmd_rx,
            );
            log::info!("Event loop stopped");
            return result;
        }

        if let Some(reason) = engine_connection_status
            .abort_reason()
            .or_else(|| self.startup_abort_reason())
        {
            self.abort_startup(reason).await?;
            Self::drain_channels(
                &mut time_evt_rx,
                &mut system_evt_rx,
                &mut system_cmd_rx,
                &mut exec_evt_rx,
                &mut exec_cmd_rx,
                &mut data_evt_rx,
                &mut data_cmd_rx,
            );
            log::info!("Event loop stopped");
            return Ok(());
        }

        debug_assert_eq!(engine_connection_status, EngineConnectionStatus::Connected);

        // Run reconciliation now that instruments are in cache and start trader
        if let Err(e) = self.perform_startup_reconciliation().await {
            let result = self.abort_startup("Startup reconciliation failed").await;
            Self::drain_channels(
                &mut time_evt_rx,
                &mut system_evt_rx,
                &mut system_cmd_rx,
                &mut exec_evt_rx,
                &mut exec_cmd_rx,
                &mut data_evt_rx,
                &mut data_cmd_rx,
            );
            log::info!("Event loop stopped");

            if let Err(finalize_err) = result {
                anyhow::bail!(
                    "startup reconciliation failed: {e}; failed to finalize startup abort: {finalize_err}"
                );
            }

            return Err(e);
        }

        if let Some(reason) = self.startup_abort_reason() {
            let result = self.abort_startup(reason).await;
            Self::drain_channels(
                &mut time_evt_rx,
                &mut system_evt_rx,
                &mut system_cmd_rx,
                &mut exec_evt_rx,
                &mut exec_cmd_rx,
                &mut data_evt_rx,
                &mut data_cmd_rx,
            );
            log::info!("Event loop stopped");
            return result;
        }

        if let Err(e) = self.kernel.start_trader() {
            let result = self.abort_after_trader_start_failure(e).await;
            Self::drain_channels(
                &mut time_evt_rx,
                &mut system_evt_rx,
                &mut system_cmd_rx,
                &mut exec_evt_rx,
                &mut exec_cmd_rx,
                &mut data_evt_rx,
                &mut data_cmd_rx,
            );
            log::info!("Event loop stopped");
            return result;
        }
        #[cfg(feature = "plugin")]
        if let Err(e) = self.plugins.start_controllers() {
            let result = self.abort_after_trader_start_failure(e).await;
            Self::drain_channels(
                &mut time_evt_rx,
                &mut system_evt_rx,
                &mut system_cmd_rx,
                &mut exec_evt_rx,
                &mut exec_cmd_rx,
                &mut data_evt_rx,
                &mut data_cmd_rx,
            );
            log::info!("Event loop stopped");
            return result;
        }

        self.process_system_events(startup_system_events);
        self.process_system_commands(startup_system_commands);

        let finish_result = {
            let mut receivers = RunnerReceivers {
                time_evt: &mut time_evt_rx,
                system_evt: &mut system_evt_rx,
                system_cmd: &mut system_cmd_rx,
                data_evt: &mut data_evt_rx,
                data_cmd: &mut data_cmd_rx,
                exec_evt: &mut exec_evt_rx,
                exec_cmd: &mut exec_cmd_rx,
            };
            self.finish_startup_trader(Some(&mut receivers)).await
        };

        match finish_result {
            Ok(true) => {}
            result => {
                log::info!("Event loop stopped");
                return result.map(|_| ());
            }
        }

        let exec_config = &self.config.exec_engine;
        let inflight_interval_ns =
            u64::from(exec_config.inflight_check_interval_ms) * NANOSECONDS_IN_MILLISECOND;
        let open_interval_ns = exec_config
            .open_check_interval_secs
            .filter(|&s| s > 0.0)
            .map_or(0, secs_to_nanos_unchecked);
        let position_interval_ns = exec_config
            .position_check_interval_secs
            .filter(|&s| s > 0.0)
            .map_or(0, secs_to_nanos_unchecked);
        let has_clients = !self
            .kernel
            .exec_engine
            .borrow()
            .get_all_clients()
            .is_empty();
        let recon_enabled = has_clients
            && (inflight_interval_ns > 0 || open_interval_ns > 0 || position_interval_ns > 0);

        let recon_min_interval = if recon_enabled {
            let mut intervals = Vec::new();

            if exec_config.inflight_check_interval_ms > 0 {
                intervals.push(Duration::from_millis(u64::from(
                    exec_config.inflight_check_interval_ms,
                )));
            }

            if let Some(s) = exec_config.open_check_interval_secs.filter(|&s| s > 0.0) {
                intervals.push(Duration::from_secs_f64(s));
            }

            if let Some(s) = exec_config
                .position_check_interval_secs
                .filter(|&s| s > 0.0)
            {
                intervals.push(Duration::from_secs_f64(s));
            }

            intervals
                .into_iter()
                .min()
                .unwrap_or(Duration::from_secs(1))
        } else {
            Duration::from_secs(1) // Unused, timer won't fire
        };

        // `reconciliation_startup_delay_secs` is a post-reconciliation grace period:
        // startup reconciliation has already completed above, and this delay offsets
        // the first periodic tick to let the system stabilize before continuous checks
        // begin.
        let startup_delay = if self.config.exec_engine.reconciliation {
            Duration::from_secs_f64(exec_config.reconciliation_startup_delay_secs)
        } else {
            Duration::ZERO
        };

        let recon_start = dst::time::Instant::now() + startup_delay;

        let mut last_inflight_check = dst::time::Instant::now();
        let mut last_open_check = last_inflight_check;
        let mut last_position_check = last_inflight_check;

        // Per-task `(interval, next_fire)` schedules dispatched by the
        // shared `maintenance_timer` below. See module docs for rationale.
        let far_future = Duration::from_hours(24 * 365 * 100);

        let make_schedule = |opt_dur: Option<Duration>| -> (Duration, dst::time::Instant) {
            let dur = opt_dur.unwrap_or(far_future);
            (dur, recon_start + dur)
        };

        let (recon_interval, mut recon_next) = make_schedule(if recon_enabled {
            Some(recon_min_interval)
        } else {
            None
        });

        let (purge_orders_interval, mut purge_orders_next) = make_schedule(
            exec_config
                .purge_closed_orders_interval_mins
                .filter(|&m| m > 0)
                .map(|m| Duration::from_secs(mins_to_secs(u64::from(m)))),
        );

        let (purge_positions_interval, mut purge_positions_next) = make_schedule(
            exec_config
                .purge_closed_positions_interval_mins
                .filter(|&m| m > 0)
                .map(|m| Duration::from_secs(mins_to_secs(u64::from(m)))),
        );

        let (purge_account_interval, mut purge_account_next) = make_schedule(
            exec_config
                .purge_account_events_interval_mins
                .filter(|&m| m > 0)
                .map(|m| Duration::from_secs(mins_to_secs(u64::from(m)))),
        );

        let (own_books_interval, mut own_books_next) = make_schedule(
            exec_config
                .own_books_audit_interval_secs
                .filter(|&s| s > 0.0)
                .map(Duration::from_secs_f64),
        );

        let (prune_fills_interval, mut prune_fills_next) =
            make_schedule(Some(Duration::from_mins(1)));

        let mut maintenance_timer = dst::time::interval(Duration::from_millis(100));
        maintenance_timer.set_missed_tick_behavior(dst::time::MissedTickBehavior::Skip);

        // Stop-check timer is not subject to the reconciliation startup delay,
        // so shutdown signals remain responsive from the moment the node reaches
        // `Running`. Set `MissedTickBehavior::Skip` so backlog ticks do not fire
        // a burst after the select arm was suspended by other branches.
        let mut stop_check_timer = dst::time::interval(Duration::from_millis(100));
        stop_check_timer.set_missed_tick_behavior(dst::time::MissedTickBehavior::Skip);

        // Running phase: runs until shutdown deadline expires
        let mut residual_events = 0usize;
        let mut open_order_report_task: Option<OpenOrderReportTask> = None;
        let mut targeted_order_report_task: Option<TargetedOrderReportTask> = None;
        let mut position_report_task: Option<PositionReportTask> = None;

        // A hosted node never installs signal handlers, so these futures stay pending and their
        // listeners are never registered. Both arms resolve to the same type as the real listeners.
        let owns_signals = mode.owns_signals();

        let ctrl_c = async move {
            if owns_signals {
                dst::signal::ctrl_c().await
            } else {
                std::future::pending::<std::io::Result<()>>().await
            }
        };

        let terminate = async move {
            if owns_signals {
                dst::signal::terminate().await
            } else {
                std::future::pending::<std::io::Result<()>>().await
            }
        };

        tokio::pin!(ctrl_c);
        tokio::pin!(terminate);

        let metrics = self.handle.metrics.clone();
        let metrics_start = dst::time::Instant::now();
        metrics.reset();

        let mut queue_monitor = self
            .config
            .queue_monitor
            .as_ref()
            .map(|config| QueueMonitor::new(config, metrics.snapshot()));
        let mut dispatches_since_yield = 0usize;

        loop {
            let shutdown_deadline = self.shutdown_deadline;
            let is_shutting_down = self.state() == NodeState::ShuttingDown;
            let is_running = self.state() == NodeState::Running;

            tokio::select! {
                biased;

                // Signal branches first so they are always checked
                result = &mut ctrl_c, if is_running => {
                    match result {
                        Ok(()) => log::info!("Received SIGINT, shutting down"),
                        Err(e) => log::error!("Failed to listen for SIGINT: {e}"),
                    }
                    self.initiate_shutdown();
                }
                result = &mut terminate, if is_running => {
                    match result {
                        Ok(()) => log::info!("Received SIGTERM, shutting down"),
                        Err(e) => log::error!("Failed to listen for SIGTERM: {e}"),
                    }
                    self.initiate_shutdown();
                }
                _ = stop_check_timer.tick(), if is_running => {
                    if stop_handle.should_stop() {
                        log::info!("Received stop signal from handle");
                        self.initiate_shutdown();
                    } else if self.kernel.is_shutdown_requested() {
                        log::info!("Received ShutdownSystem command, shutting down");
                        self.initiate_shutdown();
                    }
                }
                () = async {
                    match shutdown_deadline {
                        Some(deadline) => dst::time::sleep_until(deadline).await,
                        None => std::future::pending::<()>().await,
                    }
                }, if self.state() == NodeState::ShuttingDown => {
                    break;
                }
                result = async {
                    match open_order_report_task.as_mut() {
                        Some(task) => task.future.as_mut().await,
                        None => std::future::pending::<ReportTaskOutcome<OpenOrderReportResult>>().await,
                    }
                }, if open_order_report_task.is_some() => {
                    let maintenance_start = dst::time::Instant::now();

                    drop(open_order_report_task.take());

                    match result {
                        ReportTaskOutcome::Completed(result) => {
                            let client_refs = self
                                .exec_clients
                                .iter()
                                .map(|client| client as &dyn ExecutionClient)
                                .collect::<Vec<_>>();
                            let reconciliation = self.exec_manager.reconcile_open_order_reports(
                                &result.check,
                                result.reports,
                                &result.queried_clients,
                                &result.failed_clients,
                                &client_refs,
                            );
                            self.process_reconciliation_events(&reconciliation.events);
                            if !reconciliation.targeted_queries.is_empty() {
                                targeted_order_report_task = Some(
                                    self.start_targeted_order_report_check(
                                        reconciliation.targeted_queries,
                                    ),
                                );
                            }
                        }
                        ReportTaskOutcome::TimedOut => {
                            self.cleanup_cancelled_report_tasks(&[]);
                            log::warn!(
                                "Open-order report collection expired after {:?}",
                                self.config.timeout_reconciliation,
                            );
                        }
                    }
                    record_runner_maintenance(&metrics, maintenance_start, metrics_start);
                }
                result = async {
                    match targeted_order_report_task.as_mut() {
                        Some(task) => task.future.as_mut().await,
                        None => std::future::pending::<ReportTaskOutcome<Vec<TargetedOrderReportResult>>>().await,
                    }
                }, if targeted_order_report_task.is_some() => {
                    let maintenance_start = dst::time::Instant::now();

                    let planned_client_order_ids = targeted_order_report_task
                        .as_ref()
                        .map(|task| task.planned_client_order_ids.clone())
                        .unwrap_or_default();
                    drop(targeted_order_report_task.take());

                    match result {
                        ReportTaskOutcome::Completed(result) => {
                            let client_refs = self
                                .exec_clients
                                .iter()
                                .map(|client| client as &dyn ExecutionClient)
                                .collect::<Vec<_>>();
                            let events = self
                                .exec_manager
                                .reconcile_targeted_order_reports(result, &client_refs);
                            self.process_reconciliation_events(&events);
                        }
                        ReportTaskOutcome::TimedOut => {
                            self.cleanup_cancelled_report_tasks(&planned_client_order_ids);
                            log::warn!(
                                "Targeted order report collection expired after {:?}",
                                self.config.timeout_reconciliation,
                            );
                        }
                    }
                    record_runner_maintenance(&metrics, maintenance_start, metrics_start);
                }
                result = async {
                    match position_report_task.as_mut() {
                        Some(task) => task.future.as_mut().await,
                        None => std::future::pending::<ReportTaskOutcome<PositionReportResult>>().await,
                    }
                }, if position_report_task.is_some() => {
                    let maintenance_start = dst::time::Instant::now();

                    drop(position_report_task.take());

                    match result {
                        ReportTaskOutcome::Completed(result) => {
                            let events = self.exec_manager.reconcile_position_reports(
                                &result.check,
                                result.reports,
                                &result.queried_clients,
                                &result.failed_clients,
                            );
                            self.process_reconciliation_events(&events);
                        }
                        ReportTaskOutcome::TimedOut => {
                            self.cleanup_cancelled_report_tasks(&[]);
                            log::warn!(
                                "Position report collection expired after {:?}",
                                self.config.timeout_reconciliation,
                            );
                        }
                    }
                    record_runner_maintenance(&metrics, maintenance_start, metrics_start);
                }

                // Maintenance dispatcher (before event processing to avoid
                // starvation). See module docs for design rationale.
                _ = maintenance_timer.tick(), if is_running => {
                    let maintenance_start = dst::time::Instant::now();
                    metrics.publish_queue_depths(
                        RunnerChannelQueueDepths::from_receivers(
                            &time_evt_rx,
                            &exec_evt_rx,
                            &exec_cmd_rx,
                            &data_evt_rx,
                            &data_cmd_rx,
                        ),
                        metrics_start.elapsed(),
                    );

                    if let Some(queue_monitor) = queue_monitor.as_mut() {
                        let transitions = queue_monitor.evaluate(metrics.snapshot());
                        self.publish_queue_state_transitions(&transitions);
                    }

                    let mut now = dst::time::Instant::now();

                    if recon_enabled && now >= recon_next {
                        let recon_intervals = ReconciliationCheckIntervals {
                            inflight: Duration::from_nanos(inflight_interval_ns),
                            open: Duration::from_nanos(open_interval_ns),
                            position: Duration::from_nanos(position_interval_ns),
                        };
                        let mut recon_state = ReconciliationCheckState {
                            last_inflight_check: &mut last_inflight_check,
                            last_open_check: &mut last_open_check,
                            last_position_check: &mut last_position_check,
                            open_order_report_task: &mut open_order_report_task,
                            targeted_order_report_task: &mut targeted_order_report_task,
                            position_report_task: &mut position_report_task,
                        };

                        self.run_reconciliation_checks(
                            now,
                            recon_intervals,
                            &mut recon_state,
                        );

                        now = dst::time::Instant::now();
                        recon_next = now + recon_interval;
                    }

                    if now >= purge_orders_next {
                        self.exec_manager.purge_closed_orders();
                        purge_orders_next = now + purge_orders_interval;
                    }

                    if now >= purge_positions_next {
                        self.exec_manager.purge_closed_positions();
                        purge_positions_next = now + purge_positions_interval;
                    }

                    if now >= purge_account_next {
                        self.exec_manager.purge_account_events();
                        purge_account_next = now + purge_account_interval;
                    }

                    if now >= own_books_next {
                        self.kernel.cache().borrow_mut().audit_own_order_books();
                        own_books_next = now + own_books_interval;
                    }

                    if now >= prune_fills_next {
                        self.exec_manager.prune_recent_fills_cache(60.0);
                        self.exec_manager.prune_processed_fills();
                        self.exec_manager.prune_order_local_activity();
                        prune_fills_next = now + prune_fills_interval;
                    }

                    record_runner_maintenance(&metrics, maintenance_start, metrics_start);
                }

                // Event processing branches. Exec commands and events are
                // ordered ahead of data events so a strategy action (cancel,
                // submit, etc.) is not delayed behind a market data backlog
                // when the biased select polls receivers each iteration.
                Some(handler) = time_evt_rx.recv() => {
                    let dispatch_start = dst::time::Instant::now();
                    let dispatched = AsyncRunner::handle_time_event(handler);

                    if dispatched && is_shutting_down {
                        log::debug!("Residual time event");
                        residual_events += 1;
                    }

                    if dispatched {
                        record_runner_dispatch(
                            &metrics,
                            SystemChannel::TimeEvents,
                            dispatch_start,
                            metrics_start,
                        );
                    }
                }
                Some(event) = system_evt_rx.recv() => {
                    if is_shutting_down {
                        log::debug!("Residual system event: {event:?}");
                        residual_events += 1;
                    }
                    self.process_system_event(event);
                }
                Some(command) = system_cmd_rx.recv() => {
                    if is_shutting_down {
                        log::debug!("Residual system command: {command:?}");
                        residual_events += 1;
                    }
                    self.process_system_command(command);
                }
                Some(evt) = exec_evt_rx.recv() => {
                    let dispatch_start = dst::time::Instant::now();

                    if is_shutting_down {
                        log::debug!("Residual exec event: {evt:?}");
                        residual_events += 1;
                    }

                    self.process_exec_event(evt);
                    record_runner_dispatch(
                        &metrics,
                        SystemChannel::ExecEvents,
                        dispatch_start,
                        metrics_start,
                    );
                }
                Some(cmd) = exec_cmd_rx.recv() => {
                    let dispatch_start = dst::time::Instant::now();

                    if is_shutting_down {
                        log::debug!("Residual exec command: {cmd:?}");
                        residual_events += 1;
                    }

                    self.process_exec_command(cmd);
                    record_runner_dispatch(
                        &metrics,
                        SystemChannel::ExecCommands,
                        dispatch_start,
                        metrics_start,
                    );
                }
                message = recv_external_msgbus_message(&mut external_msgbus_rx) => {
                    let external_msgbus_start = dst::time::Instant::now();

                    match message {
                        Some(message) => {
                            if is_shutting_down {
                                log::debug!("Residual external message bus message: {message}");
                                residual_events += 1;
                            }
                            Self::republish_external_msgbus_message(&message);
                        }
                        None => {
                            log::info!("External message bus ingress closed");
                            external_msgbus_rx = None;
                            self.close_external_ingress();
                        }
                    }

                    record_runner_external_msgbus(
                        &metrics,
                        external_msgbus_start,
                        metrics_start,
                    );
                }
                Some(evt) = data_evt_rx.recv() => {
                    let dispatch_start = dst::time::Instant::now();

                    if is_shutting_down {
                        log::debug!("Residual data event: {evt:?}");
                        residual_events += 1;
                    }
                    AsyncRunner::handle_data_event(evt);
                    record_runner_dispatch(
                        &metrics,
                        SystemChannel::DataEvents,
                        dispatch_start,
                        metrics_start,
                    );
                }
                Some(cmd) = data_cmd_rx.recv() => {
                    let dispatch_start = dst::time::Instant::now();

                    if is_shutting_down {
                        log::debug!("Residual data command: {cmd:?}");
                        residual_events += 1;
                    }
                    AsyncRunner::handle_data_command(cmd);
                    record_runner_dispatch(
                        &metrics,
                        SystemChannel::DataCommands,
                        dispatch_start,
                        metrics_start,
                    );
                }
            }

            dispatches_since_yield += 1;
            if dispatches_since_yield >= DISPATCHES_PER_YIELD {
                dispatches_since_yield = 0;
                tokio::task::yield_now().await;
            }
        }

        if residual_events > 0 {
            log::debug!("Processed {residual_events} residual events during shutdown");
        }

        self.cancel_report_tasks(
            &mut open_order_report_task,
            &mut targeted_order_report_task,
            &mut position_report_task,
        );
        drop(external_msgbus_rx.take());
        let _ = self.kernel.cache().borrow().check_residuals();

        let stop_result = self.finalize_stop().await;

        // Handle events that arrived during finalize_stop
        Self::drain_channels(
            &mut time_evt_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        );

        log::info!("Event loop stopped");

        stop_result
    }

    fn publish_queue_state_transitions(&self, transitions: &[QueueStateTransition]) {
        let topic = MessagingSwitchboard::queue_state_changed_topic();

        for transition in transitions {
            let timestamp = self.kernel.generate_timestamp_ns();
            let event = QueueStateChanged::new(
                self.config.trader_id,
                transition.channel,
                transition.condition,
                transition.state,
                transition.queue_depth,
                transition.mean_dispatch_ns,
                UUID4::new(),
                timestamp,
                timestamp,
            );

            msgbus::publish_any(topic, event.as_any());
        }
    }

    #[expect(
        clippy::await_holding_refcell_ref,
        reason = "cache loading is serialized before the single-threaded live node starts"
    )]
    async fn prepare_cache(&mut self) -> anyhow::Result<()> {
        self.install_cache_database().await?;

        let cache = self.kernel.cache();
        if !cache.borrow().has_backing() {
            return Ok(());
        }

        if self
            .config
            .cache
            .as_ref()
            .is_some_and(|config| config.flush_on_start)
        {
            cache.borrow_mut().flush_db();
            return Ok(());
        }

        if self.config.exec_engine.load_cache {
            self.kernel
                .exec_engine()
                .borrow_mut()
                .load_cache()
                .await
                .context("Failed to load persistent cache")?;
        }

        Ok(())
    }

    /// Returns whether a cache database backing is configured but not yet installed.
    #[must_use]
    pub const fn has_pending_cache_database(&self) -> bool {
        self.cache_database_factory.is_some()
    }

    /// Constructs the configured cache database backing and installs it on the kernel cache.
    ///
    /// Construction is deferred to startup so the adapter is built inside the async runtime rather
    /// than by blocking the synchronous builder, and so the connection opens only when the node runs.
    async fn install_cache_database(&mut self) -> anyhow::Result<()> {
        let Some(factory) = self.cache_database_factory.as_ref() else {
            return Ok(());
        };

        let config = self.config.cache.clone().unwrap_or_default();

        // Cleared only after a successful install, so a failed startup can be retried rather than
        // silently starting without the backing the caller asked for.
        let database = factory
            .create(self.config.trader_id, self.kernel.instance_id, config)
            .await
            .context("failed to create cache database backing")?;
        self.kernel.cache().borrow_mut().set_database(database);
        self.cache_database_factory = None;

        Ok(())
    }

    fn take_external_ingress_receiver(
        &mut self,
    ) -> anyhow::Result<Option<tokio::sync::mpsc::Receiver<BusMessage>>> {
        let Some(external_ingress) = self.external_msgbus.as_mut() else {
            return Ok(None);
        };

        let receiver = external_ingress.take_receiver()?;
        log::info!("External message bus ingress started");
        Ok(Some(receiver))
    }

    fn republish_external_msgbus_message(message: &BusMessage) {
        if let Err(e) = msgbus::republish_external_message(message) {
            log::error!(
                "Failed to republish external message bus topic '{}': {e:#}",
                message.topic
            );
        }
    }

    fn close_external_ingress(&mut self) {
        if let Some(external_ingress) = self.external_msgbus.as_mut()
            && !external_ingress.is_closed()
        {
            external_ingress.close();
        }
    }

    fn process_reconciliation_events(&mut self, events: &[OrderEventAny]) {
        if events.is_empty() {
            return;
        }

        log::info!(
            "Processing {} reconciliation event{}",
            events.len(),
            if events.len() == 1 { "" } else { "s" }
        );

        for event in events {
            self.exec_manager
                .record_local_activity(event.client_order_id());
            if let OrderEventAny::Filled(fill) = event {
                self.exec_manager
                    .record_position_activity(fill.instrument_id, fill.account_id);
            }
            self.kernel.exec_engine.borrow_mut().process(event);
            if let OrderEventAny::Filled(fill) = event {
                self.exec_manager.commit_recent_fill_if_applied(fill);
            }
        }
    }

    fn process_exec_event(&mut self, event: ExecutionEvent) {
        let Some(close_ids) = self.observe_exec_event_before_dispatch(&event) else {
            return;
        };

        self.dispatch_exec_event_and_commit_fill(event);

        for client_order_id in &close_ids {
            let is_closed = self
                .kernel
                .cache()
                .borrow()
                .order(client_order_id)
                .is_some_and(|order| order.is_closed());
            if is_closed {
                self.exec_manager
                    .clear_recon_tracking(client_order_id, true);
            }
        }
    }

    fn process_exec_command(&mut self, message: TradingCommandMessage) {
        let mut messages = vec![message];
        while let Some(message) = messages.pop() {
            if message.endpoint() == MessagingSwitchboard::exec_engine_execute() {
                self.observe_exec_command_before_dispatch(message.command());
            }
            messages.extend(message.dispatch().into_iter().rev());
        }
    }

    /// Dispatches a normal-ingress execution event, then commits a direct
    /// `OrderFilled` to the recent-fills dedup cache only once it is present on
    /// its canonical order.
    ///
    /// The fill candidate is captured from `&evt` BEFORE the value is moved into
    /// [`AsyncRunner::handle_exec_event`]; the gated commit runs AFTER dispatch,
    /// so a fill the execution engine rejects (unknown order, invalid
    /// transition) is never marked and its later `Fill` report stays eligible.
    fn dispatch_exec_event_and_commit_fill(&mut self, evt: ExecutionEvent) {
        let recent_fill_candidate = match &evt {
            ExecutionEvent::Order(OrderEventAny::Filled(fill)) => Some(fill.clone()),
            _ => None,
        };

        AsyncRunner::handle_exec_event(evt);

        if let Some(fill) = &recent_fill_candidate {
            self.exec_manager.commit_recent_fill_if_applied(fill);
        }
    }

    async fn connect_data_phase(&mut self, deadline: dst::time::Instant) -> anyhow::Result<()> {
        // A zero remaining budget still admits an immediately-ready connect (an
        // empty/ready client set completes on the first poll); a pending connect
        // fails closed on that same poll. This keeps a zero `timeout_connection`
        // - a supported "do not wait, but allow ready work" configuration -
        // working, while still bounding a hung connect.
        let remaining = deadline.saturating_duration_since(dst::time::Instant::now());
        dst::time::timeout(remaining, self.kernel.connect_data_clients())
            .await
            .map_err(|_| anyhow::anyhow!("data-connect timeout"))
    }

    async fn connect_exec_clients(&mut self, deadline: dst::time::Instant) -> anyhow::Result<()> {
        let remaining = deadline.saturating_duration_since(dst::time::Instant::now());
        dst::time::timeout(remaining, self.kernel.connect_exec_clients())
            .await
            .map_err(|_| anyhow::anyhow!("exec-connect timeout"))
    }

    /// Connects execution clients and checks all engines are connected.
    ///
    /// Returns the final connection wait status.
    /// Must be called after data clients are connected and instrument events drained.
    async fn connect_exec_phase(
        &mut self,
        deadline: dst::time::Instant,
    ) -> anyhow::Result<EngineConnectionStatus> {
        self.connect_exec_clients(deadline).await?;
        Ok(self.await_engines_connected(deadline).await)
    }

    fn startup_abort_reason(&self) -> Option<&'static str> {
        if self.handle.should_stop() {
            Some("Stop signal received during startup")
        } else if self.kernel.is_shutdown_requested() {
            Some("Shutdown signal received during startup")
        } else {
            None
        }
    }

    async fn finish_startup_replay(&mut self) -> anyhow::Result<bool> {
        match self.handle.try_set_running() {
            RunningTransition::Entered => Ok(true),
            RunningTransition::StopRequested => {
                self.abort_startup("Stop signal received during startup")
                    .await?;
                Ok(false)
            }
            RunningTransition::Invalid(control) => {
                self.abort_startup_with_error(
                    "Invalid lifecycle state during startup",
                    anyhow::anyhow!(
                        "Invalid LiveNode control state {control:#04x} while entering Running"
                    ),
                )
                .await?;
                Ok(false)
            }
        }
    }

    async fn finish_startup_trader(
        &mut self,
        receivers: Option<&mut RunnerReceivers<'_>>,
    ) -> anyhow::Result<bool> {
        match self.handle.try_set_running() {
            RunningTransition::Entered => Ok(true),
            RunningTransition::StopRequested => {
                self.abort_started_trader("Stop signal received during startup", receivers)
                    .await?;
                Ok(false)
            }
            RunningTransition::Invalid(control) => {
                let state_err = anyhow::anyhow!(
                    "Invalid LiveNode control state {control:#04x} while entering Running"
                );

                match self
                    .abort_started_trader("Invalid lifecycle state during startup", receivers)
                    .await
                {
                    Ok(()) => Err(state_err),
                    Err(finalize_err) => {
                        anyhow::bail!(
                            "{state_err}; failed to finalize startup abort: {finalize_err}"
                        )
                    }
                }
            }
        }
    }

    async fn abort_startup(&mut self, reason: &str) -> anyhow::Result<()> {
        log::info!("{reason}, aborting startup");
        self.handle.set_shutting_down();
        self.finalize_stop().await
    }

    async fn abort_startup_with_error(
        &mut self,
        reason: &str,
        startup_err: anyhow::Error,
    ) -> anyhow::Result<()> {
        match self.abort_startup(reason).await {
            Ok(()) => Err(startup_err),
            Err(finalize_err) => {
                anyhow::bail!("{startup_err}; failed to finalize startup abort: {finalize_err}")
            }
        }
    }

    async fn abort_started_trader(
        &mut self,
        reason: &str,
        mut receivers: Option<&mut RunnerReceivers<'_>>,
    ) -> anyhow::Result<()> {
        log::info!("{reason}, aborting startup");
        self.handle.set_shutting_down();

        #[cfg(feature = "plugin")]
        let controller_stop_result = self.plugins.stop_controllers();
        #[cfg(not(feature = "plugin"))]
        let controller_stop_result: anyhow::Result<()> = Ok(());

        let trader_stop_result = self.kernel.stop_trader_after_start_failure();
        let delay = self.kernel.delay_post_stop();
        log::info!("Awaiting residual events ({delay:?})...");

        let residual_events = match receivers.as_mut() {
            Some(receivers) => self.process_receivers_for(delay, receivers).await,
            None => self.process_runner_for(delay).await,
        };

        if residual_events > 0 {
            log::debug!("Processed {residual_events} residual events during shutdown");
        }

        let finalize_result = self.finalize_stop().await;

        if let Some(receivers) = receivers {
            Self::drain_channels(
                receivers.time_evt,
                receivers.system_evt,
                receivers.system_cmd,
                receivers.exec_evt,
                receivers.exec_cmd,
                receivers.data_evt,
                receivers.data_cmd,
            );
        } else {
            let drained_events = self.drain_runner_pending();
            if drained_events > 0 {
                log::info!("Drained {drained_events} remaining events during shutdown");
            }
        }

        let mut errors = Vec::new();

        if let Err(e) = controller_stop_result {
            errors.push(format!("Failed to stop plug-in controllers: {e}"));
        }

        if let Err(e) = trader_stop_result {
            errors.push(format!("Failed to stop trader: {e}"));
        }

        if let Err(e) = finalize_result {
            errors.push(format!("Failed to finalize startup abort: {e}"));
        }

        if errors.is_empty() {
            Ok(())
        } else {
            anyhow::bail!("{}", errors.join("; "))
        }
    }

    async fn process_receivers_for(
        &mut self,
        duration: Duration,
        receivers: &mut RunnerReceivers<'_>,
    ) -> usize {
        let deadline = dst::time::Instant::now() + duration;
        let mut processed = 0;

        loop {
            tokio::select! {
                biased;

                () = dst::time::sleep_until(deadline) => break,
                Some(message) = receivers.time_evt.recv() => {
                    let _ = AsyncRunner::handle_time_event(message);
                    processed += 1;
                }
                Some(event) = receivers.system_evt.recv() => {
                    self.process_system_event(event);
                    processed += 1;
                }
                Some(command) = receivers.system_cmd.recv() => {
                    self.process_system_command(command);
                    processed += 1;
                }
                Some(event) = receivers.exec_evt.recv() => {
                    self.process_exec_event(event);
                    processed += 1;
                }
                Some(command) = receivers.exec_cmd.recv() => {
                    self.process_exec_command(command);
                    processed += 1;
                }
                Some(event) = receivers.data_evt.recv() => {
                    AsyncRunner::handle_data_event(event);
                    processed += 1;
                }
                Some(command) = receivers.data_cmd.recv() => {
                    AsyncRunner::handle_data_command(command);
                    processed += 1;
                }
            }
        }

        processed
    }

    async fn abort_after_trader_start_failure(
        &mut self,
        start_err: anyhow::Error,
    ) -> anyhow::Result<()> {
        log::info!("Trader startup failed, aborting startup");
        self.handle.set_shutting_down();
        let stop_result = self.kernel.stop_trader_after_start_failure();
        let finalize_result = self.finalize_stop().await;

        match (stop_result, finalize_result) {
            (Ok(()), Ok(())) => Err(start_err),
            (Err(stop_err), Ok(())) => anyhow::bail!(
                "Failed during trader startup: {start_err}; failed to stop partial trader start: \
                 {stop_err}"
            ),
            (Ok(()), Err(finalize_err)) => anyhow::bail!(
                "Failed during trader startup: {start_err}; failed to finalize startup abort: \
                 {finalize_err}"
            ),
            (Err(stop_err), Err(finalize_err)) => anyhow::bail!(
                "Failed during trader startup: {start_err}; failed to stop partial trader start: \
                 {stop_err}; failed to finalize startup abort: {finalize_err}"
            ),
        }
    }

    fn initiate_shutdown(&mut self) {
        #[cfg(feature = "plugin")]
        if let Err(e) = self.plugins.stop_controllers() {
            log::error!("Error stopping plug-in controllers: {e}");
        }
        self.kernel.stop_trader();
        let delay = self.kernel.delay_post_stop();
        log::info!("Awaiting residual events ({delay:?})...");

        self.shutdown_deadline = Some(dst::time::Instant::now() + delay);
        self.handle.set_shutting_down();
    }

    async fn finalize_stop(&mut self) -> anyhow::Result<()> {
        self.close_external_ingress();

        let timeout = self.config.timeout_disconnection;
        let deadline = dst::time::Instant::now() + timeout;
        let disconnect_result =
            match dst::time::timeout(timeout, self.kernel.disconnect_clients()).await {
                Ok(result) => result,
                Err(_) => Err(anyhow::anyhow!(
                    "disconnect timeout while disconnecting clients"
                )),
            };

        if let Err(ref e) = disconnect_result {
            log::error!("Error disconnecting clients: {e}");
        }

        let readiness_result = self.await_engines_disconnected(deadline).await;
        let kernel_result = self.kernel.finalize_stop().await;

        self.handle.set_stopped();

        let mut errors = Vec::new();
        if let Err(e) = disconnect_result {
            errors.push(e.to_string());
        }

        if let Err(e) = readiness_result {
            errors.push(format!("failed while awaiting engine disconnection: {e}"));
        }

        if let Err(e) = kernel_result {
            errors.push(format!("failed while finalizing kernel shutdown: {e}"));
        }

        if errors.is_empty() {
            Ok(())
        } else {
            anyhow::bail!("{}", errors.join("; "))
        }
    }

    fn drain_channels(
        time_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<TimeEventMessage>,
        system_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<SystemEvent>,
        system_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<SystemCommand>,
        exec_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<ExecutionEvent>,
        exec_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<TradingCommandMessage>,
        data_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<DataEvent>,
        data_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<DataCommand>,
    ) {
        let mut drained = 0;

        while let Ok(handler) = time_evt_rx.try_recv() {
            let _ = AsyncRunner::handle_time_event(handler);
            drained += 1;
        }

        while system_evt_rx.try_recv().is_ok() {
            drained += 1;
        }

        while system_cmd_rx.try_recv().is_ok() {
            drained += 1;
        }

        while let Ok(evt) = data_evt_rx.try_recv() {
            AsyncRunner::handle_data_event(evt);
            drained += 1;
        }

        while let Ok(cmd) = data_cmd_rx.try_recv() {
            AsyncRunner::handle_data_command(cmd);
            drained += 1;
        }

        while let Ok(evt) = exec_evt_rx.try_recv() {
            AsyncRunner::handle_exec_event(evt);
            drained += 1;
        }

        while let Ok(cmd) = exec_cmd_rx.try_recv() {
            AsyncRunner::handle_trading_command(cmd);
            drained += 1;
        }

        if drained > 0 {
            log::info!("Drained {drained} remaining events during shutdown");
        }
    }

    fn observe_exec_event_before_dispatch(
        &mut self,
        evt: &ExecutionEvent,
    ) -> Option<Vec<ClientOrderId>> {
        let mut close_ids = Vec::new();

        match evt {
            ExecutionEvent::Order(order_evt) => {
                self.exec_manager.observe_order_event(order_evt);
                close_ids.push(order_evt.client_order_id());
            }
            ExecutionEvent::OrderSubmittedBatch(batch) => {
                for submitted in &batch.events {
                    self.exec_manager
                        .record_local_activity(submitted.client_order_id);
                }
            }
            ExecutionEvent::OrderAcceptedBatch(batch) => {
                for accepted in &batch.events {
                    self.exec_manager
                        .clear_recon_tracking(&accepted.client_order_id, true);
                    self.exec_manager
                        .record_local_activity(accepted.client_order_id);
                }
            }
            ExecutionEvent::OrderCanceledBatch(batch) => {
                for canceled in &batch.events {
                    self.exec_manager
                        .clear_recon_tracking(&canceled.client_order_id, true);
                    self.exec_manager
                        .record_local_activity(canceled.client_order_id);
                    close_ids.push(canceled.client_order_id);
                }
            }
            ExecutionEvent::Report(report) => {
                if let ExecutionReport::Fill(fill_report) = report
                    && self.exec_manager.is_fill_recently_processed(
                        fill_report.account_id,
                        fill_report.instrument_id,
                        fill_report.trade_id,
                    )
                {
                    log::debug!(
                        "Skipping recently processed fill report: {}",
                        fill_report.trade_id,
                    );
                    return None;
                }
                self.exec_manager.observe_execution_report(report);

                if let Some(client_order_id) = Self::closed_order_report_client_order_id(report) {
                    close_ids.push(client_order_id);
                }
            }
            ExecutionEvent::Account(_) => {}
        }

        Some(close_ids)
    }

    fn closed_order_report_client_order_id(report: &ExecutionReport) -> Option<ClientOrderId> {
        match report {
            ExecutionReport::Order(order_report)
            | ExecutionReport::OrderWithFills(order_report, _)
                if order_report.order_status.is_closed() =>
            {
                order_report.client_order_id
            }
            _ => None,
        }
    }

    fn observe_exec_command_before_dispatch(&mut self, cmd: &TradingCommand) {
        match cmd {
            TradingCommand::SubmitOrder(submit) => {
                self.exec_manager.register_inflight(submit.client_order_id);
            }
            TradingCommand::SubmitOrderList(submit) => {
                for order_init in &submit.order_inits {
                    self.exec_manager
                        .register_inflight(order_init.client_order_id);
                }
            }
            TradingCommand::ModifyOrder(modify) => {
                self.exec_manager.register_inflight(modify.client_order_id);
            }
            TradingCommand::ModifyOrders(modify) => {
                for child in &modify.modifies {
                    self.exec_manager.register_inflight(child.client_order_id);
                }
            }
            TradingCommand::CancelOrder(cancel) => {
                self.exec_manager.register_inflight(cancel.client_order_id);
            }
            TradingCommand::CancelOrders(cancel) => {
                for child in &cancel.cancels {
                    self.exec_manager.register_inflight(child.client_order_id);
                }
            }
            _ => {}
        }
    }

    /// Gets the node's environment.
    #[must_use]
    pub fn environment(&self) -> Environment {
        self.kernel.environment()
    }

    /// Gets a reference to the underlying kernel.
    #[must_use]
    pub const fn kernel(&self) -> &NautilusKernel {
        &self.kernel
    }

    /// Gets an exclusive reference to the underlying kernel.
    #[must_use]
    pub const fn kernel_mut(&mut self) -> &mut NautilusKernel {
        &mut self.kernel
    }

    /// Gets the node's trader ID.
    #[must_use]
    pub fn trader_id(&self) -> TraderId {
        self.kernel.trader_id()
    }

    /// Gets the node's instance ID.
    #[must_use]
    pub const fn instance_id(&self) -> UUID4 {
        self.kernel.instance_id()
    }

    /// Returns the current node state.
    #[must_use]
    pub fn state(&self) -> NodeState {
        self.handle.state()
    }

    /// Checks if the live node is currently running.
    #[must_use]
    pub fn is_running(&self) -> bool {
        self.state().is_running()
    }

    /// Sets the cache database adapter for persistence.
    ///
    /// This allows setting a database adapter (e.g., PostgreSQL, Redis) after the node
    /// is built but before it starts running. The database adapter is used to persist
    /// cache data for recovery and state management.
    ///
    /// # Errors
    ///
    /// Returns an error if the node is already running.
    pub fn set_cache_database(
        &mut self,
        database: Box<dyn CacheDatabaseAdapter>,
    ) -> anyhow::Result<()> {
        if self.state() != NodeState::Idle {
            anyhow::bail!(
                "Cannot set cache database while node is running, set it before running the node"
            );
        }

        self.kernel.cache().borrow_mut().set_database(database);
        Ok(())
    }

    /// Returns the execution manager.
    #[must_use]
    pub fn exec_manager(&self) -> &ExecutionManager {
        &self.exec_manager
    }

    /// Returns a mutable reference to the execution manager.
    #[must_use]
    pub fn exec_manager_mut(&mut self) -> &mut ExecutionManager {
        &mut self.exec_manager
    }

    /// Adds an actor to the trader.
    ///
    /// This method provides a high-level interface for adding actors to the underlying
    /// trader without requiring direct access to the kernel. Actors should be added
    /// after the node is built but before starting the node.
    ///
    /// # Errors
    ///
    /// Returns an error if:
    /// - The trader is not in a valid state for adding components.
    /// - An actor with the same ID is already registered.
    /// - The node is currently running.
    pub fn add_actor<T>(&mut self, actor: T) -> anyhow::Result<()>
    where
        T: DataActor + DataActorNative + Component + Actor + 'static,
    {
        if self.state() != NodeState::Idle {
            anyhow::bail!(
                "Cannot add actor while node is running, add actors before running the node"
            );
        }

        self.kernel.trader.borrow_mut().add_actor(actor)
    }

    /// Adds an actor to the live node using a factory function.
    ///
    /// The factory function is called at registration time to create the actor,
    /// avoiding cloning issues with non-cloneable actor types.
    ///
    /// # Errors
    ///
    /// Returns an error if:
    /// - The node is currently running.
    /// - The factory function fails to create the actor.
    /// - The underlying trader registration fails.
    pub fn add_actor_from_factory<F, T>(&mut self, factory: F) -> anyhow::Result<()>
    where
        F: FnOnce() -> anyhow::Result<T>,
        T: DataActor + DataActorNative + Component + Actor + 'static,
    {
        if self.state() != NodeState::Idle {
            anyhow::bail!(
                "Cannot add actor while node is running, add actors before running the node"
            );
        }

        self.kernel
            .trader
            .borrow_mut()
            .add_actor_from_factory(factory)
    }

    /// Adds a strategy to the trader.
    ///
    /// Strategies are registered in both the component registry (for lifecycle management)
    /// and the actor registry (for data callbacks via msgbus).
    ///
    /// # Errors
    ///
    /// Returns an error if:
    /// - The node is currently running.
    /// - A strategy with the same ID is already registered.
    /// - The strategy configures one or more external order claims and the request repeats
    ///   an instrument, or either tier already contains a requested claim.
    /// - The strategy configures one or more external order claims or an OMS type override,
    ///   and the execution engine is already borrowed. A strategy configuring neither does
    ///   not take the borrow and cannot fail this way.
    pub fn add_strategy<T>(&mut self, mut strategy: T) -> anyhow::Result<()>
    where
        T: Strategy + StrategyNative + DataActorNative + Component + Debug + 'static,
    {
        if self.state() != NodeState::Idle {
            anyhow::bail!(
                "Cannot add strategy while node is running, add strategies before running the node"
            );
        }

        // Capture strategy-owned values before adding the strategy, which moves it
        let strategy_id = self
            .kernel
            .trader
            .borrow()
            .prepare_strategy_for_registration(&mut strategy)?;
        let oms_type = StrategyNative::strategy_core(&strategy).config.oms_type;
        let claims = strategy.external_order_claims().unwrap_or_default();

        // The engine borrow is only needed for claims or an OMS override; a
        // strategy requiring neither must not fail on an unavailable borrow.
        let mut exec_engine = if claims.is_empty() && oms_type.is_none() {
            None
        } else {
            Some(self.kernel.exec_engine.try_borrow_mut().map_err(|e| {
                anyhow::anyhow!("Cannot register external order claims or OMS type: {e}")
            })?)
        };
        let instrument_ids = match &exec_engine {
            Some(exec_engine) => Self::preflight_external_order_claims(
                &self.exec_manager,
                exec_engine,
                strategy_id,
                &claims,
            )?,
            None => HashSet::new(),
        };

        self.kernel.trader.borrow_mut().add_strategy(strategy)?;

        // No fallible operation may follow the trader addition: the commits
        // below are infallible against the preflighted request.
        if let Some(exec_engine) = &mut exec_engine {
            exec_engine.commit_external_order_claims(strategy_id, &instrument_ids);
            self.exec_manager
                .register_external_order_claims(strategy_id, &instrument_ids);

            if let Some(oms_type) = oms_type {
                exec_engine.register_oms_type(strategy_id, oms_type);
            }
        }

        Ok(())
    }

    /// Registers external order claims on both live execution tiers.
    ///
    /// The operation is synchronous and atomic across the reconciliation manager and execution
    /// engine. It can be called while the node is idle, after manual [`start`](Self::start)
    /// returns, or after the node stops. It cannot be called while [`run`](Self::run) or
    /// [`run_with_mode`](Self::run_with_mode) owns the node.
    ///
    /// # Errors
    ///
    /// Returns an error without changing either tier if the execution engine is already borrowed,
    /// the request repeats an instrument, or either tier already contains any requested claim.
    pub fn register_external_order_claims(
        &mut self,
        strategy_id: StrategyId,
        claims: &[InstrumentId],
    ) -> anyhow::Result<()> {
        let mut exec_engine = self
            .kernel
            .exec_engine
            .try_borrow_mut()
            .map_err(|e| anyhow::anyhow!("Cannot register external order claims: {e}"))?;
        let instrument_ids = Self::preflight_external_order_claims(
            &self.exec_manager,
            &exec_engine,
            strategy_id,
            claims,
        )?;

        exec_engine.commit_external_order_claims(strategy_id, &instrument_ids);
        self.exec_manager
            .register_external_order_claims(strategy_id, &instrument_ids);

        Ok(())
    }

    fn preflight_external_order_claims(
        exec_manager: &ExecutionManager,
        exec_engine: &ExecutionEngine,
        strategy_id: StrategyId,
        claims: &[InstrumentId],
    ) -> anyhow::Result<HashSet<InstrumentId>> {
        let mut instrument_ids = HashSet::new();

        for instrument_id in claims {
            if !instrument_ids.insert(*instrument_id) {
                anyhow::bail!(
                    "External order claim for {instrument_id} already exists for {strategy_id}"
                );
            }
        }

        for instrument_id in &instrument_ids {
            if let Some(existing) = exec_manager.get_external_order_claim(instrument_id) {
                anyhow::bail!(
                    "External order claim for {instrument_id} already exists for {existing}"
                );
            }

            if let Some(existing) = exec_engine.get_external_order_claim(instrument_id) {
                anyhow::bail!(
                    "External order claim for {instrument_id} already exists for {existing}"
                );
            }
        }

        Ok(instrument_ids)
    }

    /// Deregisters all external order claims owned by `strategy_id` from both execution tiers.
    ///
    /// Remove the strategy through the trader or controller first, then call this method before
    /// registering a successor. The operation is synchronous and can be called while the node is
    /// idle, after manual [`start`](Self::start) returns, or after the node stops. It cannot be
    /// called while [`run`](Self::run) or [`run_with_mode`](Self::run_with_mode) owns the node.
    ///
    /// # Errors
    ///
    /// Returns an error without changing either tier if the execution engine is already borrowed
    /// or the two tiers do not contain identical claim sets for the strategy.
    pub fn deregister_external_order_claims(
        &mut self,
        strategy_id: StrategyId,
    ) -> anyhow::Result<()> {
        let mut exec_engine = self
            .kernel
            .exec_engine
            .try_borrow_mut()
            .map_err(|e| anyhow::anyhow!("Cannot deregister external order claims: {e}"))?;
        let manager_instruments = self
            .exec_manager
            .get_external_order_claims_for_strategy(strategy_id);
        let engine_instruments = exec_engine.get_external_order_claims_for_strategy(strategy_id);

        if manager_instruments != engine_instruments {
            anyhow::bail!(
                "External order claims for {strategy_id} differ between the execution manager and engine"
            );
        }

        exec_engine.deregister_external_order_claims(strategy_id);
        self.exec_manager
            .deregister_external_order_claims(strategy_id);

        Ok(())
    }

    /// Adds an execution algorithm to the trader.
    ///
    /// Execution algorithms are registered in both the component registry (for lifecycle
    /// management) and the actor registry (for data callbacks via msgbus).
    ///
    /// # Errors
    ///
    /// Returns an error if:
    /// - The node is currently running.
    /// - An execution algorithm with the same ID is already registered.
    pub fn add_exec_algorithm<T>(&mut self, exec_algorithm: T) -> anyhow::Result<()>
    where
        T: ExecutionAlgorithm + ExecutionAlgorithmNative + Component + Debug + 'static,
    {
        if self.state() != NodeState::Idle {
            anyhow::bail!(
                "Cannot add exec algorithm while node is running, add exec algorithms before running the node"
            );
        }

        self.kernel
            .trader
            .borrow_mut()
            .add_exec_algorithm(exec_algorithm)
    }

    // Runs reconciliation sub-checks, each gated by its own interval.
    // Continuous checks only schedule venue work; they do not await venue I/O
    // in the event loop.
    fn run_reconciliation_checks(
        &mut self,
        now: dst::time::Instant,
        intervals: ReconciliationCheckIntervals,
        state: &mut ReconciliationCheckState<'_>,
    ) {
        if reconciliation_check_due(now, *state.last_inflight_check, intervals.inflight) {
            if self.state() == NodeState::ShuttingDown {
                return;
            }
            let result = self.exec_manager.check_inflight_orders();
            self.process_reconciliation_events(&result.events);
            for cmd in result.queries {
                AsyncRunner::handle_exec_command(cmd);
            }
            *state.last_inflight_check = now;
        }

        let open_due = reconciliation_check_due(now, *state.last_open_check, intervals.open);
        let position_due =
            reconciliation_check_due(now, *state.last_position_check, intervals.position);

        if (open_due || position_due) && self.state() == NodeState::ShuttingDown {
            return;
        }

        if state.open_order_report_task.is_some() || state.targeted_order_report_task.is_some() {
            if open_due {
                log::debug!("Open-order reconciliation already in progress");
                *state.last_open_check = now;
            }

            if position_due {
                log::debug!(
                    "Position reconciliation delayed: open-order reconciliation in progress"
                );
            }

            return;
        }

        if state.position_report_task.is_some() {
            if position_due {
                log::debug!("Position reconciliation already in progress");
                *state.last_position_check = now;
            }

            if open_due {
                log::debug!(
                    "Open-order reconciliation delayed: position reconciliation in progress"
                );
            }

            return;
        }

        if position_due && (!open_due || *state.last_position_check < *state.last_open_check) {
            *state.position_report_task = self.start_position_report_check();
            *state.last_position_check = now;
        } else if open_due {
            *state.open_order_report_task = self.start_open_order_report_check();
            *state.last_open_check = now;
        }
    }

    fn start_open_order_report_check(&mut self) -> Option<OpenOrderReportTask> {
        if self.exec_clients.is_empty() {
            log::debug!("No execution clients to check orders consistency");
            return None;
        }

        let client_refs = self
            .exec_clients
            .iter()
            .map(|client| client as &dyn ExecutionClient)
            .collect::<Vec<_>>();
        let check = self
            .exec_manager
            .prepare_open_order_report_check(UUID4::new(), &client_refs);
        let command = check.command.clone();
        let clients = self.exec_clients.clone();
        let deadline = dst::time::Instant::now() + self.config.timeout_reconciliation;

        Some(OpenOrderReportTask {
            future: Box::pin(async move {
                let remaining = deadline.saturating_duration_since(dst::time::Instant::now());
                match dst::time::timeout(remaining, request_open_order_reports(clients, command))
                    .await
                {
                    Ok(result) => ReportTaskOutcome::Completed(OpenOrderReportResult {
                        check,
                        reports: result.reports,
                        queried_clients: result.queried_clients,
                        failed_clients: result.failed_clients,
                    }),
                    Err(_) => ReportTaskOutcome::TimedOut,
                }
            }),
        })
    }

    fn start_targeted_order_report_check(
        &self,
        queries: Vec<TargetedOrderQuery>,
    ) -> TargetedOrderReportTask {
        let clients = self.exec_clients.clone();
        let query_delay = Duration::from_millis(u64::from(
            self.config.exec_engine.single_order_query_delay_ms,
        ));
        let planned_client_order_ids = queries
            .iter()
            .map(TargetedOrderQuery::client_order_id)
            .collect();
        let deadline = dst::time::Instant::now() + self.config.timeout_reconciliation;

        TargetedOrderReportTask {
            future: Box::pin(async move {
                let client_refs = clients
                    .iter()
                    .map(|client| client as &dyn ExecutionClient)
                    .collect::<Vec<_>>();
                let remaining = deadline.saturating_duration_since(dst::time::Instant::now());
                match dst::time::timeout(
                    remaining,
                    request_targeted_order_reports(&client_refs, queries, query_delay),
                )
                .await
                {
                    Ok(result) => ReportTaskOutcome::Completed(result),
                    Err(_) => ReportTaskOutcome::TimedOut,
                }
            }),
            planned_client_order_ids,
        }
    }

    fn start_position_report_check(&self) -> Option<PositionReportTask> {
        if self.exec_clients.is_empty() {
            log::debug!("No execution clients to check positions consistency");
            return None;
        }

        let client_refs = self
            .exec_clients
            .iter()
            .map(|client| client as &dyn ExecutionClient)
            .collect::<Vec<_>>();
        let check = self
            .exec_manager
            .prepare_position_report_check(UUID4::new(), &client_refs);
        let command = check.command.clone();
        let clients = self.exec_clients.clone();
        let deadline = dst::time::Instant::now() + self.config.timeout_reconciliation;

        Some(PositionReportTask {
            future: Box::pin(async move {
                let remaining = deadline.saturating_duration_since(dst::time::Instant::now());
                match dst::time::timeout(remaining, request_position_reports(clients, command))
                    .await
                {
                    Ok(result) => ReportTaskOutcome::Completed(PositionReportResult {
                        check,
                        reports: result.reports,
                        queried_clients: result.queried_clients,
                        failed_clients: result.failed_clients,
                    }),
                    Err(_) => ReportTaskOutcome::TimedOut,
                }
            }),
        })
    }

    fn flush_pending_exec_client_instruments(&self) {
        for client in &self.exec_clients {
            client.flush_pending_instruments();
        }
    }

    fn cleanup_cancelled_report_tasks(&mut self, planned_client_order_ids: &[ClientOrderId]) {
        self.flush_pending_exec_client_instruments();
        self.exec_manager
            .remove_targeted_order_queries(planned_client_order_ids);
    }

    fn cancel_report_tasks(
        &mut self,
        open_order_report_task: &mut Option<OpenOrderReportTask>,
        targeted_order_report_task: &mut Option<TargetedOrderReportTask>,
        position_report_task: &mut Option<PositionReportTask>,
    ) {
        let planned_client_order_ids = targeted_order_report_task
            .as_ref()
            .map(|task| task.planned_client_order_ids.clone())
            .unwrap_or_default();

        drop(open_order_report_task.take());
        drop(targeted_order_report_task.take());
        drop(position_report_task.take());
        self.cleanup_cancelled_report_tasks(&planned_client_order_ids);
    }
}

fn record_runner_dispatch(
    metrics: &RunnerMetrics,
    channel: SystemChannel,
    dispatch_start: dst::time::Instant,
    metrics_start: dst::time::Instant,
) {
    let dispatch_end = dst::time::Instant::now();
    metrics.record_dispatch(
        channel,
        dispatch_end.duration_since(dispatch_start),
        dispatch_end.duration_since(metrics_start),
    );
}

fn record_runner_maintenance(
    metrics: &RunnerMetrics,
    work_start: dst::time::Instant,
    metrics_start: dst::time::Instant,
) {
    let work_end = dst::time::Instant::now();
    metrics.record_maintenance(
        work_end.duration_since(work_start),
        work_end.duration_since(metrics_start),
    );
}

fn record_runner_external_msgbus(
    metrics: &RunnerMetrics,
    work_start: dst::time::Instant,
    metrics_start: dst::time::Instant,
) {
    let work_end = dst::time::Instant::now();
    metrics.record_external_msgbus(
        work_end.duration_since(work_start),
        work_end.duration_since(metrics_start),
    );
}

async fn recv_external_msgbus_message(
    rx: &mut Option<tokio::sync::mpsc::Receiver<BusMessage>>,
) -> Option<BusMessage> {
    match rx {
        Some(rx) => rx.recv().await,
        None => std::future::pending::<Option<BusMessage>>().await,
    }
}

async fn request_open_order_reports(
    clients: Vec<LiveExecutionClient>,
    command: GenerateOrderStatusReports,
) -> OpenOrderReportQueryResult {
    let mut all_reports = Vec::new();
    let mut queried_clients = IndexSet::new();
    let mut failed_clients = IndexSet::new();

    for client in clients {
        let client_id = client.client_id();
        queried_clients.insert(client_id);

        match client.generate_order_status_reports(&command).await {
            Ok(reports) => {
                all_reports.extend(
                    reports
                        .into_iter()
                        .map(|report| SourcedOrderStatusReport { client_id, report }),
                );
            }
            Err(e) => {
                failed_clients.insert(client_id);
                log::warn!(
                    "Failed to generate order status reports from {}: {e}",
                    client.client_id()
                );
            }
        }
    }

    OpenOrderReportQueryResult {
        reports: all_reports,
        queried_clients,
        failed_clients,
    }
}

async fn request_position_reports(
    clients: Vec<LiveExecutionClient>,
    command: GeneratePositionStatusReports,
) -> PositionReportQueryResult {
    let mut all_reports = Vec::new();
    let mut queried_clients = IndexSet::new();
    let mut failed_clients = IndexSet::new();

    for client in clients {
        let client_id = client.client_id();
        queried_clients.insert(client_id);

        match client.generate_position_status_reports(&command).await {
            Ok(reports) => {
                all_reports.extend(reports);
            }
            Err(e) => {
                failed_clients.insert(client_id);
                log::warn!(
                    "Failed to generate position status reports from {}: {e}",
                    client.client_id()
                );
            }
        }
    }

    PositionReportQueryResult {
        reports: all_reports,
        queried_clients,
        failed_clients,
    }
}

fn reconciliation_check_due(
    now: dst::time::Instant,
    last: dst::time::Instant,
    interval: Duration,
) -> bool {
    interval > Duration::ZERO
        && now
            .checked_duration_since(last)
            .is_some_and(|elapsed| elapsed >= interval)
}

#[derive(Clone, Copy)]
struct ReconciliationCheckIntervals {
    inflight: Duration,
    open: Duration,
    position: Duration,
}

struct ReconciliationCheckState<'a> {
    last_inflight_check: &'a mut dst::time::Instant,
    last_open_check: &'a mut dst::time::Instant,
    last_position_check: &'a mut dst::time::Instant,
    open_order_report_task: &'a mut Option<OpenOrderReportTask>,
    targeted_order_report_task: &'a mut Option<TargetedOrderReportTask>,
    position_report_task: &'a mut Option<PositionReportTask>,
}

enum ReportTaskOutcome<T> {
    Completed(T),
    TimedOut,
}

type OpenOrderReportFuture =
    Pin<Box<dyn Future<Output = ReportTaskOutcome<OpenOrderReportResult>>>>;

struct OpenOrderReportTask {
    future: OpenOrderReportFuture,
}

struct OpenOrderReportResult {
    check: OpenOrderReportCheck,
    reports: Vec<SourcedOrderStatusReport>,
    queried_clients: IndexSet<ClientId>,
    failed_clients: IndexSet<ClientId>,
}

type TargetedOrderReportFuture =
    Pin<Box<dyn Future<Output = ReportTaskOutcome<Vec<TargetedOrderReportResult>>>>>;

struct TargetedOrderReportTask {
    future: TargetedOrderReportFuture,
    planned_client_order_ids: Vec<ClientOrderId>,
}

struct OpenOrderReportQueryResult {
    reports: Vec<SourcedOrderStatusReport>,
    queried_clients: IndexSet<ClientId>,
    failed_clients: IndexSet<ClientId>,
}

type PositionReportFuture = Pin<Box<dyn Future<Output = ReportTaskOutcome<PositionReportResult>>>>;

struct PositionReportTask {
    future: PositionReportFuture,
}

struct PositionReportResult {
    check: PositionReportCheck,
    reports: Vec<PositionStatusReport>,
    queried_clients: IndexSet<ClientId>,
    failed_clients: IndexSet<ClientId>,
}

struct PositionReportQueryResult {
    reports: Vec<PositionStatusReport>,
    queried_clients: IndexSet<ClientId>,
    failed_clients: IndexSet<ClientId>,
}

struct RunnerReceivers<'a> {
    time_evt: &'a mut tokio::sync::mpsc::UnboundedReceiver<TimeEventMessage>,
    system_evt: &'a mut tokio::sync::mpsc::UnboundedReceiver<SystemEvent>,
    system_cmd: &'a mut tokio::sync::mpsc::UnboundedReceiver<SystemCommand>,
    exec_evt: &'a mut tokio::sync::mpsc::UnboundedReceiver<ExecutionEvent>,
    exec_cmd: &'a mut tokio::sync::mpsc::UnboundedReceiver<TradingCommandMessage>,
    data_evt: &'a mut tokio::sync::mpsc::UnboundedReceiver<DataEvent>,
    data_cmd: &'a mut tokio::sync::mpsc::UnboundedReceiver<DataCommand>,
}

/// Flushes data events and commands from both `pending` and the channel receivers
/// into the cache, looping until no progress is made.
///
/// This closes the gap where `drive_with_event_buffering` exits as soon as its
/// driven future resolves (biased select), leaving items in the channel receivers
/// that were not captured into `pending`.
fn flush_pending_data(
    pending: &mut PendingEvents,
    data_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<DataEvent>,
    data_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<DataCommand>,
) {
    loop {
        let mut progressed = pending.drain_data();

        while let Ok(evt) = data_evt_rx.try_recv() {
            AsyncRunner::handle_data_event(evt);
            progressed = true;
        }

        while let Ok(cmd) = data_cmd_rx.try_recv() {
            AsyncRunner::handle_data_command(cmd);
            progressed = true;
        }

        if !progressed {
            break;
        }
    }
}

/// Flushes all channel receivers into `pending`, then drains everything.
///
/// Unlike [`flush_pending_data`] this is a single pass, not a drain-until-quiet
/// loop. Sufficient for phase 2 where the goal is to capture items the biased
/// select did not poll before the connect future resolved.
#[expect(
    clippy::too_many_arguments,
    reason = "all runner receivers are drained together"
)]
fn flush_all_pending(
    pending: &mut PendingEvents,
    time_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<TimeEventMessage>,
    system_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<SystemEvent>,
    system_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<SystemCommand>,
    exec_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<ExecutionEvent>,
    exec_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<TradingCommandMessage>,
    data_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<DataEvent>,
    data_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<DataCommand>,
) {
    // Flush channel receivers into pending
    while let Ok(handler) = time_evt_rx.try_recv() {
        let _ = AsyncRunner::handle_time_event(handler);
    }

    while let Ok(event) = system_evt_rx.try_recv() {
        pending.system_events.push(event);
    }

    while let Ok(command) = system_cmd_rx.try_recv() {
        pending.system_commands.push(command);
    }

    while let Ok(evt) = data_evt_rx.try_recv() {
        pending.data_evts.push(evt);
    }

    while let Ok(cmd) = data_cmd_rx.try_recv() {
        pending.data_cmds.push(cmd);
    }

    while let Ok(evt) = exec_evt_rx.try_recv() {
        match evt {
            ExecutionEvent::Account(_) => {
                AsyncRunner::handle_exec_event(evt);
            }
            ExecutionEvent::Report(report) => {
                pending.exec_reports.push(report);
            }
            ExecutionEvent::Order(order_evt) => {
                pending.order_evts.push(order_evt);
            }
            ExecutionEvent::OrderSubmittedBatch(batch) => {
                for submitted in batch {
                    pending.order_evts.push(OrderEventAny::Submitted(submitted));
                }
            }
            ExecutionEvent::OrderAcceptedBatch(batch) => {
                for accepted in batch {
                    pending.order_evts.push(OrderEventAny::Accepted(accepted));
                }
            }
            ExecutionEvent::OrderCanceledBatch(batch) => {
                for canceled in batch {
                    pending.order_evts.push(OrderEventAny::Canceled(canceled));
                }
            }
        }
    }

    while let Ok(cmd) = exec_cmd_rx.try_recv() {
        pending.exec_cmds.push(cmd);
    }

    pending.drain();
}

/// Drives a future to completion while buffering channel events.
///
/// Time events are handled immediately. Account events are forwarded directly.
/// All other events are buffered in `pending` for later processing.
#[expect(
    clippy::too_many_arguments,
    reason = "startup buffering owns one future plus the pending state and all runner receivers"
)]
async fn drive_with_event_buffering<F: std::future::Future>(
    future: F,
    pending: &mut PendingEvents,
    time_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<TimeEventMessage>,
    system_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<SystemEvent>,
    system_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<SystemCommand>,
    exec_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<ExecutionEvent>,
    exec_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<TradingCommandMessage>,
    data_evt_rx: &mut tokio::sync::mpsc::UnboundedReceiver<DataEvent>,
    data_cmd_rx: &mut tokio::sync::mpsc::UnboundedReceiver<DataCommand>,
) -> F::Output {
    tokio::pin!(future);

    loop {
        tokio::select! {
            biased;

            result = &mut future => {
                break result;
            }
            Some(handler) = time_evt_rx.recv() => {
                let _ = AsyncRunner::handle_time_event(handler);
            }
            Some(event) = system_evt_rx.recv() => {
                pending.system_events.push(event);
            }
            Some(command) = system_cmd_rx.recv() => {
                pending.system_commands.push(command);
            }
            Some(evt) = exec_evt_rx.recv() => {
                // Account events are safe to process immediately. Report and
                // Order events need ExecEngine borrow_mut which may conflict
                // with the borrow held by the driven future.
                match evt {
                    ExecutionEvent::Account(_) => {
                        AsyncRunner::handle_exec_event(evt);
                    }
                    ExecutionEvent::Report(report) => {
                        pending.exec_reports.push(report);
                    }
                    ExecutionEvent::Order(order_evt) => {
                        pending.order_evts.push(order_evt);
                    }
                    ExecutionEvent::OrderSubmittedBatch(batch) => {
                        for submitted in batch {
                            pending.order_evts.push(OrderEventAny::Submitted(submitted));
                        }
                    }
                    ExecutionEvent::OrderAcceptedBatch(batch) => {
                        for accepted in batch {
                            pending.order_evts.push(OrderEventAny::Accepted(accepted));
                        }
                    }
                    ExecutionEvent::OrderCanceledBatch(batch) => {
                        for canceled in batch {
                            pending.order_evts.push(OrderEventAny::Canceled(canceled));
                        }
                    }
                }
            }
            Some(cmd) = exec_cmd_rx.recv() => {
                pending.exec_cmds.push(cmd);
            }
            Some(evt) = data_evt_rx.recv() => {
                pending.data_evts.push(evt);
            }
            Some(cmd) = data_cmd_rx.recv() => {
                pending.data_cmds.push(cmd);
            }
        }
    }
}

#[derive(Default)]
struct PendingEvents {
    system_events: Vec<SystemEvent>,
    system_commands: Vec<SystemCommand>,
    data_evts: Vec<DataEvent>,
    data_cmds: Vec<DataCommand>,
    exec_reports: Vec<ExecutionReport>,
    order_evts: Vec<OrderEventAny>,
    exec_cmds: Vec<TradingCommandMessage>,
}

impl PendingEvents {
    fn is_empty(&self) -> bool {
        self.system_events.is_empty()
            && self.system_commands.is_empty()
            && self.data_evts.is_empty()
            && self.data_cmds.is_empty()
            && self.exec_reports.is_empty()
            && self.order_evts.is_empty()
            && self.exec_cmds.is_empty()
    }

    /// Drains only data events and commands into the cache.
    ///
    /// Returns `true` if any events or commands were drained.
    fn drain_data(&mut self) -> bool {
        let total = self.data_evts.len() + self.data_cmds.len();

        if total > 0 {
            log::debug!(
                "Draining {total} data events/commands into cache \
                 (data_evts={}, data_cmds={})",
                self.data_evts.len(),
                self.data_cmds.len(),
            );
        }

        for evt in self.data_evts.drain(..) {
            AsyncRunner::handle_data_event(evt);
        }

        for cmd in self.data_cmds.drain(..) {
            AsyncRunner::handle_data_command(cmd);
        }

        total > 0
    }

    /// Drains all remaining pending events.
    fn drain(&mut self) {
        let total = self.data_evts.len()
            + self.data_cmds.len()
            + self.exec_reports.len()
            + self.order_evts.len()
            + self.exec_cmds.len();

        if total > 0 {
            log::debug!(
                "Processing {total} events/commands queued during startup \
                 (data_evts={}, data_cmds={}, exec_reports={}, order_evts={}, exec_cmds={})",
                self.data_evts.len(),
                self.data_cmds.len(),
                self.exec_reports.len(),
                self.order_evts.len(),
                self.exec_cmds.len()
            );
        }

        for evt in self.data_evts.drain(..) {
            AsyncRunner::handle_data_event(evt);
        }

        for cmd in self.data_cmds.drain(..) {
            AsyncRunner::handle_data_command(cmd);
        }

        for report in self.exec_reports.drain(..) {
            AsyncRunner::handle_exec_event(ExecutionEvent::Report(report));
        }

        for evt in self.order_evts.drain(..) {
            AsyncRunner::handle_exec_event(ExecutionEvent::Order(evt));
        }

        for cmd in self.exec_cmds.drain(..) {
            AsyncRunner::handle_trading_command(cmd);
        }
    }

    fn take_system_events(&mut self) -> Vec<SystemEvent> {
        std::mem::take(&mut self.system_events)
    }

    fn take_system_commands(&mut self) -> Vec<SystemCommand> {
        std::mem::take(&mut self.system_commands)
    }
}

struct ClientStatus {
    client: String,
    client_type: &'static str,
    connected: bool,
}

fn render_client_statuses(rows: Vec<ClientStatus>) -> String {
    let mut builder = Builder::with_capacity(rows.len() + 1, 3);
    builder.push_record(["Client", "Type", "Connected"]);

    for row in rows {
        builder.push_record([
            row.client,
            row.client_type.to_string(),
            row.connected.to_string(),
        ]);
    }

    builder.build().with(Style::rounded()).to_string()
}

#[cfg(test)]
mod tests {
    use std::{
        cell::{Cell, RefCell},
        fmt::Debug,
        rc::Rc,
        sync::{
            Arc, Mutex,
            atomic::{AtomicBool, Ordering},
        },
    };

    use bytes::Bytes;
    use indexmap::IndexMap;
    use log::{Level, LevelFilter, Log, Metadata, Record};
    #[cfg(feature = "python")]
    use nautilus_common::runner::{
        SyncDataCommandSender, SyncTradingCommandSender, replace_data_cmd_sender,
        replace_exec_cmd_sender,
    };
    use nautilus_common::{
        actor::{DataActor, DataActorCore, data_actor::DataActorConfig},
        cache::Cache,
        clock::{Clock, TestClock},
        enums::SerializationEncoding,
        live::runner::{get_data_event_sender, get_exec_event_sender, get_system_event_sender},
        messages::{
            execution::{QueryAccount, SubmitOrder, TradingCommand},
            system::{
                QueueCondition, QueueState, ReconnectSocket, SocketState, SocketStateChanged,
            },
        },
        msgbus::{
            self, BusMessage, BusPayloadType, MessageBusBacking, MessageBusBackingFactory,
            MessageBusConfig, MessageBusExternalEgress, MessageBusExternalIngress,
            MessagingSwitchboard, ShareableMessageHandler, TypedHandler, TypedIntoHandler,
        },
        nautilus_actor,
        testing::wait_until_async,
    };
    use nautilus_core::{UUID4, UnixNanos};
    use nautilus_execution::{
        engine::{ExecutionEngine, SnapshotAnchorer, stubs::StubExecutionClient},
        reconciliation::create_inferred_fill_for_qty,
    };
    use nautilus_model::{
        accounts::{AccountAny, MarginAccount},
        data::QuoteTick,
        enums::{
            AccountType, LiquiditySide, OmsType, OrderSide, OrderStatus, OrderType, TimeInForce,
        },
        events::{
            AccountState, OrderAcceptedBatch, OrderFilled,
            order::spec::{OrderAcceptedSpec, OrderPendingUpdateSpec, OrderUpdatedSpec},
        },
        identifiers::{
            AccountId, ActorId, ClientId, InstrumentId, PositionId, StrategyId, TradeId, TraderId,
            Venue, VenueOrderId,
        },
        instruments::{Instrument, InstrumentAny, stubs::crypto_perpetual_ethusdt},
        orders::{OrderTestBuilder, stubs::TestOrderEventStubs},
        reports::FillReport,
        types::{AccountBalance, Currency, Money, Price, Quantity},
    };
    use nautilus_system::{KernelEventStore, RegisteredComponents, event_store::EventStoreConfig};
    use nautilus_testkit::{
        cache::TestCacheDatabaseControl,
        components::{StateActor, StateStrategy},
    };
    use nautilus_trading::{
        nautilus_strategy,
        strategy::{config::StrategyConfig, core::StrategyCore},
    };
    use rstest::*;
    use rust_decimal_macros::dec;
    use ustr::Ustr;

    use super::*;

    struct ExternalIngressLogCapture {
        messages: Mutex<Vec<String>>,
    }

    static EXTERNAL_INGRESS_LOG_CAPTURE: ExternalIngressLogCapture = ExternalIngressLogCapture {
        messages: Mutex::new(Vec::new()),
    };

    #[derive(Debug)]
    struct StartupSocketActor {
        core: DataActorCore,
        received: Rc<RefCell<Vec<SocketStateChanged>>>,
    }

    impl StartupSocketActor {
        fn new(received: Rc<RefCell<Vec<SocketStateChanged>>>) -> Self {
            Self {
                core: DataActorCore::new(DataActorConfig {
                    actor_id: Some(ActorId::from("SOCKET-STARTUP-ACTOR")),
                    ..Default::default()
                }),
                received,
            }
        }
    }

    impl DataActor for StartupSocketActor {
        fn on_start(&mut self) -> anyhow::Result<()> {
            self.subscribe_socket_state(None);
            Ok(())
        }

        fn on_socket_state(&mut self, event: &SocketStateChanged) -> anyhow::Result<()> {
            self.received.borrow_mut().push(event.clone());
            Ok(())
        }
    }

    nautilus_actor!(StartupSocketActor);

    impl Log for ExternalIngressLogCapture {
        fn enabled(&self, metadata: &Metadata<'_>) -> bool {
            metadata.level() == Level::Error && metadata.target() == "nautilus_live::node"
        }

        fn log(&self, record: &Record<'_>) {
            if self.enabled(record.metadata()) {
                self.messages
                    .lock()
                    .unwrap()
                    .push(record.args().to_string());
            }
        }

        fn flush(&self) {}
    }

    #[rstest]
    fn test_render_client_statuses() {
        let rows = vec![
            ClientStatus {
                client: "BINANCE".to_string(),
                client_type: "Data",
                connected: true,
            },
            ClientStatus {
                client: "SIM".to_string(),
                client_type: "Execution",
                connected: false,
            },
        ];

        let output = render_client_statuses(rows);
        let expected = "╭─────────┬───────────┬───────────╮\n\
│ Client  │ Type      │ Connected │\n\
├─────────┼───────────┼───────────┤\n\
│ BINANCE │ Data      │ true      │\n\
│ SIM     │ Execution │ false     │\n\
╰─────────┴───────────┴───────────╯";

        assert_eq!(output, expected);
    }

    #[rstest]
    fn test_republish_external_msgbus_message_logs_topic_and_error_chain() {
        log::set_logger(&EXTERNAL_INGRESS_LOG_CAPTURE).expect("test logger already installed");
        log::set_max_level(LevelFilter::Error);
        EXTERNAL_INGRESS_LOG_CAPTURE
            .messages
            .lock()
            .unwrap()
            .clear();
        let message = BusMessage::with_str_topic(
            "data.quotes.AUDUSD.SIM*",
            BusPayloadType::Custom(Ustr::from("UnregisteredCustomData")),
            Bytes::new(),
            SerializationEncoding::Json,
        );

        LiveNode::republish_external_msgbus_message(&message);

        assert_eq!(
            *EXTERNAL_INGRESS_LOG_CAPTURE.messages.lock().unwrap(),
            vec![
                "Failed to republish external message bus topic 'data.quotes.AUDUSD.SIM*': invalid \
                 external message topic: Topic `value` contained invalid characters, was \
                 data.quotes.AUDUSD.SIM*"
                    .to_string()
            ],
        );
    }

    #[rstest]
    fn test_publish_queue_state_transitions_reaches_typed_subscriber() {
        let config = LiveNodeConfig {
            trader_id: TraderId::from("QUEUE-001"),
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            ..Default::default()
        };
        let node = LiveNode::build("QueuePublicationNode".to_string(), Some(config)).unwrap();
        let received = Rc::new(RefCell::new(Vec::<QueueStateChanged>::new()));

        let handler = ShareableMessageHandler::from_typed({
            let received = received.clone();
            move |event: &QueueStateChanged| received.borrow_mut().push(event.clone())
        });

        msgbus::subscribe_any(
            MessagingSwitchboard::queue_state_changed_topic().into(),
            handler,
            None,
        );
        let transitions = [
            QueueStateTransition {
                channel: SystemChannel::DataEvents,
                condition: QueueCondition::Backlogged,
                state: QueueState::Triggered,
                queue_depth: 17,
                mean_dispatch_ns: 23,
            },
            QueueStateTransition {
                channel: SystemChannel::DataEvents,
                condition: QueueCondition::Slow,
                state: QueueState::Triggered,
                queue_depth: 17,
                mean_dispatch_ns: 23,
            },
        ];

        node.publish_queue_state_transitions(&transitions);

        let events = received.borrow();
        assert_eq!(events.len(), 2);

        for (event, transition) in events.iter().zip(transitions) {
            assert_eq!(event.trader_id, TraderId::from("QUEUE-001"));
            assert_eq!(event.channel, transition.channel);
            assert_eq!(event.condition, transition.condition);
            assert_eq!(event.state, transition.state);
            assert_eq!(event.queue_depth, transition.queue_depth);
            assert_eq!(event.mean_dispatch_ns, transition.mean_dispatch_ns);
            assert_ne!(event.event_id, UUID4::default());
            assert_ne!(event.ts_event, UnixNanos::default());
            assert_eq!(event.ts_init, event.ts_event);
        }
        assert_ne!(events[0].event_id, events[1].event_id);
        drop(events);
        msgbus::get_message_bus().borrow_mut().dispose();
    }

    #[rstest]
    fn test_process_socket_state_change_reaches_typed_subscriber() {
        let config = LiveNodeConfig {
            trader_id: TraderId::from("SOCKET-001"),
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            ..Default::default()
        };
        let node = LiveNode::build("SocketPublicationNode".to_string(), Some(config)).unwrap();
        let received = Rc::new(RefCell::new(Vec::<SocketStateChanged>::new()));
        let handler = ShareableMessageHandler::from_typed({
            let received = received.clone();
            move |event: &SocketStateChanged| received.borrow_mut().push(event.clone())
        });
        msgbus::subscribe_any(
            MessagingSwitchboard::socket_state_changed_topic().into(),
            handler,
            None,
        );
        let change = SocketStateChange::new(
            ClientId::from("BINANCE"),
            Some(Venue::from("BINANCE")),
            Ustr::from("binance-futures-market-streams"),
            SocketState::Disconnected,
        );

        node.process_system_event(SystemEvent::SocketState(change));

        let events = received.borrow();
        assert_eq!(events.len(), 1);
        assert_eq!(events[0].trader_id, TraderId::from("SOCKET-001"));
        assert_eq!(events[0].client_id, ClientId::from("BINANCE"));
        assert_eq!(events[0].venue, Some(Venue::from("BINANCE")));
        assert_eq!(
            events[0].endpoint,
            Ustr::from("binance-futures-market-streams")
        );
        assert_eq!(events[0].state, SocketState::Disconnected);
        assert_ne!(events[0].event_id, UUID4::default());
        assert_ne!(events[0].ts_event, UnixNanos::default());
        assert_eq!(events[0].ts_init, events[0].ts_event);
        drop(events);
        msgbus::get_message_bus().borrow_mut().dispose();
    }

    #[rstest]
    #[tokio::test]
    async fn test_start_publishes_socket_change_after_actor_subscribes() {
        let config = LiveNodeConfig {
            trader_id: TraderId::from("SOCKET-STARTUP-001"),
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            timeout_connection: Duration::ZERO,
            timeout_reconciliation: Duration::ZERO,
            timeout_portfolio: Duration::ZERO,
            timeout_disconnection: Duration::ZERO,
            delay_post_stop: Duration::ZERO,
            timeout_shutdown: Duration::ZERO,
            ..Default::default()
        };
        let mut node = LiveNode::build("SocketStartupNode".to_string(), Some(config)).unwrap();
        let received = Rc::new(RefCell::new(Vec::new()));
        node.add_actor(StartupSocketActor::new(Rc::clone(&received)))
            .unwrap();
        node.runner.as_ref().unwrap().bind_senders();
        let change = SocketStateChange::new(
            ClientId::from("BINANCE"),
            Some(Venue::from("BINANCE")),
            Ustr::from("binance-futures-market-streams"),
            SocketState::Connected,
        );
        get_system_event_sender()
            .send(SystemEvent::SocketState(change))
            .unwrap();

        node.start().await.unwrap();

        {
            let events = received.borrow();
            assert_eq!(events.len(), 1);
            assert_eq!(events[0].trader_id, TraderId::from("SOCKET-STARTUP-001"));
            assert_eq!(events[0].client_id, change.client_id);
            assert_eq!(events[0].venue, change.venue);
            assert_eq!(events[0].endpoint, change.endpoint);
            assert_eq!(events[0].state, change.state);
            assert_ne!(events[0].event_id, UUID4::default());
            assert_ne!(events[0].ts_event, UnixNanos::default());
            assert_eq!(events[0].ts_init, events[0].ts_event);
        }

        node.stop().await.unwrap();
        node.dispose();
    }

    #[rstest]
    #[tokio::test(flavor = "current_thread")]
    async fn test_run_publishes_queue_state_after_dispatch_sample() {
        let config = LiveNodeConfig {
            trader_id: TraderId::from("QUEUE-RUN-001"),
            queue_monitor: Some(crate::config::QueueMonitorConfig {
                queue_depth_trigger: usize::MAX,
                queue_depth_clear: 0,
                mean_dispatch_ns_trigger: 1,
                mean_dispatch_ns_clear: 0,
            }),
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            delay_post_stop: Duration::ZERO,
            ..Default::default()
        };
        let mut node = LiveNode::build("QueueMonitorRunNode".to_string(), Some(config)).unwrap();
        let handle = node.handle();
        let received = Rc::new(RefCell::new(Vec::<QueueStateChanged>::new()));

        let handler = ShareableMessageHandler::from_typed({
            let received = received.clone();
            let stop_handle = handle.clone();

            move |event: &QueueStateChanged| {
                received.borrow_mut().push(event.clone());
                stop_handle.stop();
            }
        });

        msgbus::subscribe_any(
            MessagingSwitchboard::queue_state_changed_topic().into(),
            handler,
            None,
        );
        let drive_handle = handle.clone();

        let result = tokio::time::timeout(Duration::from_secs(5), async {
            let run = node.run();
            tokio::pin!(run);

            let drive = async move {
                wait_until_async(
                    || async { drive_handle.is_running() },
                    Duration::from_secs(2),
                )
                .await;
                get_data_event_sender().send(stub_data_event()).unwrap();
            };

            let (run_result, ()) = tokio::join!(run, drive);
            run_result
        })
        .await;

        assert!(
            result.is_ok(),
            "queue state event should arrive before timeout"
        );
        assert!(result.unwrap().is_ok(), "run() should succeed");
        let events = received.borrow();
        assert_eq!(events.len(), 1);
        assert_eq!(events[0].trader_id, TraderId::from("QUEUE-RUN-001"));
        assert_eq!(events[0].channel, SystemChannel::DataEvents);
        assert_eq!(events[0].condition, QueueCondition::Slow);
        assert_eq!(events[0].state, QueueState::Triggered);
        assert_eq!(events[0].queue_depth, 0);
        assert!(events[0].mean_dispatch_ns > 0);
        assert_ne!(events[0].event_id, UUID4::default());
        assert_ne!(events[0].ts_event, UnixNanos::default());
        assert_eq!(events[0].ts_init, events[0].ts_event);
        drop(events);
        msgbus::get_message_bus().borrow_mut().dispose();
    }

    #[rstest]
    fn test_observe_exec_event_before_dispatch_skips_recent_fill_report() {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            ..Default::default()
        };
        let mut node = LiveNode::build("FillSkipNode".to_string(), Some(config)).unwrap();
        let event = stub_exec_event();
        let account_id = AccountId::from("TEST-001");
        let instrument_id = InstrumentId::from("TEST.VENUE");
        let trade_id = TradeId::from("T-001");

        let close_ids = node.observe_exec_event_before_dispatch(&event);
        assert_eq!(close_ids, Some(Vec::new()));
        assert!(
            !node
                .exec_manager
                .is_fill_recently_processed(account_id, instrument_id, trade_id)
        );

        node.exec_manager
            .mark_fill_processed(account_id, instrument_id, trade_id);

        let close_ids = node.observe_exec_event_before_dispatch(&event);
        assert_eq!(close_ids, None);
    }

    #[rstest]
    #[case(false, false, OrderStatus::Canceled, 1)]
    #[case(false, true, OrderStatus::Accepted, 0)]
    #[case(true, false, OrderStatus::Canceled, 1)]
    #[case(true, true, OrderStatus::Accepted, 0)]
    fn test_process_exec_event_clears_terminal_activity_only_after_cached_order_closes(
        #[case] with_fills: bool,
        #[case] superseded: bool,
        #[case] expected_status: OrderStatus,
        #[case] expected_query_count: usize,
    ) {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: true,
                open_check_threshold_ms: 5_000,
                single_order_query_delay_ms: 0,
                ..Default::default()
            },
            ..Default::default()
        };
        let mut node = LiveNode::build("TerminalReportNode".to_string(), Some(config)).unwrap();
        let client_order_id = ClientOrderId::from("O-TERMINAL-REPORT");
        let old_venue_order_id = VenueOrderId::from("V-TERMINAL-REPORT-OLD");
        let new_venue_order_id = VenueOrderId::from("V-TERMINAL-REPORT-NEW");
        let account_id = AccountId::from("TEST-001");
        let client_id = ClientId::from("TEST");
        let instrument = crypto_perpetual_ethusdt();
        let instrument_id = instrument.id();
        let account = AccountAny::Margin(MarginAccount::new(
            AccountState::new(
                account_id,
                AccountType::Margin,
                vec![AccountBalance::new(
                    Money::from("1000000 USDT"),
                    Money::from("0 USDT"),
                    Money::from("1000000 USDT"),
                )],
                Vec::new(),
                true,
                UUID4::new(),
                UnixNanos::default(),
                UnixNanos::default(),
                Some(Currency::USDT()),
            ),
            true,
        ));
        node.kernel.cache.borrow_mut().add_account(account).unwrap();
        node.kernel
            .cache
            .borrow_mut()
            .add_instrument(InstrumentAny::CryptoPerpetual(instrument))
            .unwrap();
        insert_accepted_limit_order_in_node(
            &node,
            account_id,
            client_id,
            instrument_id,
            client_order_id,
            old_venue_order_id,
        );

        if superseded {
            let order = node
                .kernel
                .cache
                .borrow()
                .order_owned(&client_order_id)
                .unwrap();
            let pending_update = OrderPendingUpdateSpec::builder()
                .trader_id(order.trader_id())
                .strategy_id(order.strategy_id())
                .instrument_id(order.instrument_id())
                .client_order_id(client_order_id)
                .account_id(account_id)
                .venue_order_id(old_venue_order_id)
                .build();
            node.kernel
                .cache
                .borrow_mut()
                .update_order(&OrderEventAny::PendingUpdate(pending_update))
                .unwrap();
            let order = node
                .kernel
                .cache
                .borrow()
                .order_owned(&client_order_id)
                .unwrap();
            let updated = OrderUpdatedSpec::builder()
                .trader_id(order.trader_id())
                .strategy_id(order.strategy_id())
                .instrument_id(order.instrument_id())
                .client_order_id(client_order_id)
                .quantity(order.quantity())
                .venue_order_id(new_venue_order_id)
                .account_id(account_id)
                .build();
            node.kernel
                .cache
                .borrow_mut()
                .update_order(&OrderEventAny::Updated(updated))
                .unwrap();
        }

        let report = OrderStatusReport::new(
            account_id,
            instrument_id,
            Some(client_order_id),
            old_venue_order_id,
            OrderSide::Buy,
            OrderType::Limit,
            TimeInForce::Gtc,
            OrderStatus::Canceled,
            Quantity::from("10.0"),
            Quantity::from("0.0"),
            UnixNanos::from(1_000),
            UnixNanos::from(2_000),
            UnixNanos::from(3_000),
            None,
        );
        let report = if with_fills {
            ExecutionReport::OrderWithFills(Box::new(report), Vec::new())
        } else {
            ExecutionReport::Order(Box::new(report))
        };
        let event = ExecutionEvent::Report(report);

        node.process_exec_event(event);

        let order = node
            .kernel
            .cache
            .borrow()
            .order_owned(&client_order_id)
            .unwrap();
        let expected_venue_order_id = if superseded {
            new_venue_order_id
        } else {
            old_venue_order_id
        };

        assert_eq!(order.status(), expected_status);
        assert_eq!(order.venue_order_id(), Some(expected_venue_order_id));

        if !superseded {
            let replacement = OrderTestBuilder::new(OrderType::Limit)
                .client_order_id(client_order_id)
                .instrument_id(instrument_id)
                .quantity(Quantity::from("20.0"))
                .price(Price::from("200.0"))
                .build();
            let submitted = TestOrderEventStubs::submitted(&replacement, account_id);
            node.kernel
                .cache
                .borrow_mut()
                .add_order(replacement, None, Some(client_id), true)
                .unwrap();
            let replacement = node
                .kernel
                .cache
                .borrow_mut()
                .update_order(&submitted)
                .unwrap();
            let accepted =
                TestOrderEventStubs::accepted(&replacement, account_id, old_venue_order_id);
            node.kernel
                .cache
                .borrow_mut()
                .update_order(&accepted)
                .unwrap();
        }

        assert_eq!(
            node.exec_manager.check_open_order_queries().len(),
            expected_query_count,
        );
    }

    #[rstest]
    fn test_rejected_direct_fill_stays_eligible_for_later_report() {
        let (mut node, mut fill_event, _) = recent_fill_test_fixture("RejectedDirectFillNode");
        let OrderEventAny::Filled(fill) = &mut fill_event else {
            unreachable!();
        };
        fill.client_order_id = ClientOrderId::from("O-UNKNOWN");
        fill.venue_order_id = VenueOrderId::from("V-UNKNOWN");
        let fill = fill.clone();
        let report_event = fill_report_event(&fill);
        let event = ExecutionEvent::Order(OrderEventAny::Filled(fill.clone()));

        assert!(node.observe_exec_event_before_dispatch(&event).is_some());
        let marked_before_dispatch = is_recent_fill(&node, &fill);

        node.dispatch_exec_event_and_commit_fill(event);

        let marked_after_dispatch = is_recent_fill(&node, &fill);
        let later_report_is_eligible = node
            .observe_exec_event_before_dispatch(&report_event)
            .is_some();
        assert_eq!(
            (
                marked_before_dispatch,
                marked_after_dispatch,
                later_report_is_eligible,
            ),
            (false, false, true),
        );
    }

    #[rstest]
    fn test_applied_direct_fill_commits_and_skips_later_report() {
        let (mut node, fill_event, _) = recent_fill_test_fixture("AppliedDirectFillNode");
        let OrderEventAny::Filled(fill) = &fill_event else {
            unreachable!();
        };
        let fill = fill.clone();
        let report_event = fill_report_event(&fill);
        let event = ExecutionEvent::Order(fill_event);

        assert!(node.observe_exec_event_before_dispatch(&event).is_some());
        assert!(!is_recent_fill(&node, &fill));

        node.dispatch_exec_event_and_commit_fill(event);

        assert!(is_recent_fill(&node, &fill));
        assert_eq!(node.observe_exec_event_before_dispatch(&report_event), None);
    }

    #[rstest]
    fn test_canonical_duplicate_fill_counts_as_applied() {
        let (mut node, fill_event, _) = recent_fill_test_fixture("DuplicateDirectFillNode");
        let OrderEventAny::Filled(fill) = &fill_event else {
            unreachable!();
        };
        let mut fill = fill.clone();
        node.kernel
            .cache
            .borrow_mut()
            .update_order(&fill_event)
            .unwrap();
        fill.client_order_id = ClientOrderId::from("O-DUPLICATE-UNKNOWN");

        node.exec_manager.commit_recent_fill_if_applied(&fill);

        assert!(is_recent_fill(&node, &fill));
    }

    #[rstest]
    #[case(false)]
    #[case(true)]
    fn test_continuous_reconciliation_commits_only_applied_fill(#[case] applied: bool) {
        let (mut node, mut fill_event, _) = recent_fill_test_fixture(if applied {
            "AppliedContinuousFillNode"
        } else {
            "RejectedContinuousFillNode"
        });

        if !applied {
            let OrderEventAny::Filled(fill) = &mut fill_event else {
                unreachable!();
            };
            fill.client_order_id = ClientOrderId::from("O-CONTINUOUS-UNKNOWN");
            fill.venue_order_id = VenueOrderId::from("V-CONTINUOUS-UNKNOWN");
        }
        let OrderEventAny::Filled(fill) = &fill_event else {
            unreachable!();
        };
        let fill = fill.clone();

        node.process_reconciliation_events(&[fill_event]);

        assert_eq!(is_recent_fill(&node, &fill), applied);
    }

    #[rstest]
    fn test_recent_fill_commit_requires_account_and_instrument_match() {
        let (mut node, fill_event, _) = recent_fill_test_fixture("MismatchedDirectFillNode");
        node.kernel
            .cache
            .borrow_mut()
            .update_order(&fill_event)
            .unwrap();
        let OrderEventAny::Filled(fill) = fill_event else {
            unreachable!();
        };
        let mut account_mismatch = fill.clone();
        account_mismatch.account_id = AccountId::from("OTHER-001");
        let mut instrument_mismatch = fill;
        instrument_mismatch.instrument_id = InstrumentId::from("OTHER.VENUE");

        node.exec_manager
            .commit_recent_fill_if_applied(&account_mismatch);
        node.exec_manager
            .commit_recent_fill_if_applied(&instrument_mismatch);

        assert!(!is_recent_fill(&node, &account_mismatch));
        assert!(!is_recent_fill(&node, &instrument_mismatch));
    }

    #[rstest]
    fn test_applied_inferred_fill_remains_recently_processed() {
        let (mut node, _, instrument) = recent_fill_test_fixture("InferredFillNode");
        let client_order_id = ClientOrderId::from("O-RECENT-FILL");
        let venue_order_id = VenueOrderId::from("V-RECENT-FILL");
        let account_id = AccountId::from("TEST-001");
        let order = node
            .kernel
            .cache
            .borrow()
            .order_owned(&client_order_id)
            .unwrap();
        let report = OrderStatusReport::new(
            account_id,
            instrument.id(),
            Some(client_order_id),
            venue_order_id,
            OrderSide::Buy,
            OrderType::Limit,
            TimeInForce::Gtc,
            OrderStatus::PartiallyFilled,
            Quantity::from("10.0"),
            Quantity::from("1.0"),
            UnixNanos::from(1_000),
            UnixNanos::from(1_000),
            UnixNanos::from(1_000),
            None,
        )
        .with_avg_px(dec!(100.0));
        let inferred = create_inferred_fill_for_qty(
            &order,
            &report,
            &account_id,
            &instrument,
            Quantity::from("1.0"),
            UnixNanos::from(1_000),
            None,
        )
        .unwrap();
        let OrderEventAny::Filled(fill) = &inferred else {
            unreachable!();
        };
        let fill = fill.clone();

        node.process_reconciliation_events(&[inferred]);

        assert!(fill.reconciliation);
        assert!(is_recent_fill(&node, &fill));
    }

    #[rstest]
    fn test_observe_exec_event_before_dispatch_accepted_batch_stamps_local_activity() {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: true,
                open_check_threshold_ms: 5_000,
                single_order_query_delay_ms: 0,
                ..Default::default()
            },
            ..Default::default()
        };
        let mut node = LiveNode::build("AcceptedBatchNode".to_string(), Some(config)).unwrap();
        let account_id = AccountId::from("TEST-ACCEPTED-BATCH-001");
        let client_id = ClientId::from("TEST-ACCEPTED-BATCH");
        let instrument = crypto_perpetual_ethusdt();
        let instrument_id = instrument.id();
        let client_order_id = ClientOrderId::from("O-ACCEPTED-BATCH");
        let venue_order_id = VenueOrderId::from("V-ACCEPTED-BATCH");

        node.kernel
            .cache
            .borrow_mut()
            .add_instrument(InstrumentAny::CryptoPerpetual(instrument))
            .unwrap();
        insert_accepted_limit_order_in_node(
            &node,
            account_id,
            client_id,
            instrument_id,
            client_order_id,
            venue_order_id,
        );

        assert_eq!(node.exec_manager.check_open_order_queries().len(), 1);

        let accepted = OrderAcceptedSpec::builder()
            .instrument_id(instrument_id)
            .client_order_id(client_order_id)
            .venue_order_id(venue_order_id)
            .account_id(account_id)
            .build();
        let event = ExecutionEvent::OrderAcceptedBatch(OrderAcceptedBatch::new(vec![accepted]));

        let close_ids = node.observe_exec_event_before_dispatch(&event);

        assert_eq!(close_ids, Some(Vec::new()));
        assert!(node.exec_manager.check_open_order_queries().is_empty());
    }

    #[rstest]
    #[cfg_attr(
        not(all(feature = "simulation", madsim)),
        tokio::test(start_paused = true)
    )]
    #[cfg_attr(all(feature = "simulation", madsim), madsim::test)]
    async fn test_batch_cancel_command_registers_each_child_for_inflight_timeout() {
        use nautilus_common::messages::execution::{BatchCancelOrders, CancelOrder};
        use nautilus_model::{events::OrderPendingCancel, identifiers::ClientOrderId};

        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: true,
                inflight_check_threshold_ms: 100,
                inflight_check_retries: 1,
                ..Default::default()
            },
            ..Default::default()
        };
        let mut node = LiveNode::build("BatchCancelNode".to_string(), Some(config)).unwrap();
        let trader_id = TraderId::from("TESTER-001");
        let strategy_id = StrategyId::from("S-BATCH-CANCEL");
        let account_id = AccountId::from("TEST-001");
        let instrument = crypto_perpetual_ethusdt();
        let instrument_id = instrument.id();
        let child_ids = [
            ClientOrderId::from("O-BATCH-CANCEL-1"),
            ClientOrderId::from("O-BATCH-CANCEL-2"),
        ];
        node.kernel
            .cache
            .borrow_mut()
            .add_instrument(InstrumentAny::CryptoPerpetual(instrument))
            .unwrap();

        for client_order_id in child_ids {
            let order = OrderTestBuilder::new(OrderType::Limit)
                .trader_id(trader_id)
                .strategy_id(strategy_id)
                .client_order_id(client_order_id)
                .instrument_id(instrument_id)
                .quantity(Quantity::from("10.0"))
                .price(Price::from("100.0"))
                .build();
            let venue_order_id = VenueOrderId::from(format!("V-{client_order_id}").as_str());
            // Model the production batch-cancel path: each child is accepted, then
            // moved to PendingCancel, so an inflight timeout must emit a Canceled
            // event (not a Submitted-order rejection).
            let submitted = TestOrderEventStubs::submitted(&order, account_id);
            let accepted = TestOrderEventStubs::accepted(&order, account_id, venue_order_id);
            let pending_cancel = OrderEventAny::PendingCancel(OrderPendingCancel::new(
                trader_id,
                strategy_id,
                instrument_id,
                client_order_id,
                Some(account_id),
                UUID4::new(),
                UnixNanos::default(),
                UnixNanos::default(),
                false,
                Some(venue_order_id),
            ));
            let mut cache = node.kernel.cache.borrow_mut();
            cache.add_order(order, None, None, false).unwrap();
            cache.update_order(&submitted).unwrap();
            cache.update_order(&accepted).unwrap();
            cache.update_order(&pending_cancel).unwrap();
        }
        let cancels = child_ids
            .into_iter()
            .map(|client_order_id| {
                CancelOrder::new(
                    trader_id,
                    None,
                    strategy_id,
                    instrument_id,
                    client_order_id,
                    None,
                    UUID4::new(),
                    UnixNanos::default(),
                    None,
                    None,
                )
            })
            .collect();
        let command = TradingCommand::CancelOrders(BatchCancelOrders::new(
            trader_id,
            None,
            strategy_id,
            instrument_id,
            cancels,
            UUID4::new(),
            UnixNanos::default(),
            None,
            None,
        ));

        node.observe_exec_command_before_dispatch(&command);
        advance_clock(Duration::from_millis(101)).await;
        let result = node.exec_manager.check_inflight_orders();
        let timed_out_ids = result
            .events
            .iter()
            .map(OrderEventAny::client_order_id)
            .collect::<IndexSet<_>>();

        assert_eq!(timed_out_ids, IndexSet::from(child_ids));
        assert_eq!(result.events.len(), child_ids.len());
        assert!(
            result
                .events
                .iter()
                .all(|event| matches!(event, OrderEventAny::Canceled(_))),
            "batch-cancel children must time out as Canceled events",
        );
    }

    #[rstest]
    #[cfg_attr(
        not(all(feature = "simulation", madsim)),
        tokio::test(start_paused = true)
    )]
    #[cfg_attr(all(feature = "simulation", madsim), madsim::test)]
    async fn test_risk_bound_command_does_not_register_inflight() {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: true,
                inflight_check_threshold_ms: 100,
                inflight_check_retries: 2,
                ..Default::default()
            },
            ..Default::default()
        };
        let mut node = LiveNode::build("RiskBoundNode".to_string(), Some(config)).unwrap();
        msgbus::register_trading_command_endpoint(
            MessagingSwitchboard::risk_engine_execute(),
            TypedIntoHandler::from(|_: TradingCommand| {}),
        );
        let instrument = crypto_perpetual_ethusdt();
        let instrument_id = instrument.id();
        let order = OrderTestBuilder::new(OrderType::Limit)
            .trader_id(node.trader_id())
            .strategy_id(StrategyId::from("S-RISK-DENIED"))
            .instrument_id(instrument_id)
            .side(OrderSide::NoOrderSide)
            .quantity(Quantity::from("1.000"))
            .price(Price::from("100.00"))
            .build();
        let client_order_id = order.client_order_id();

        {
            let mut cache = node.kernel.cache.borrow_mut();
            cache
                .add_instrument(InstrumentAny::CryptoPerpetual(instrument))
                .unwrap();
            cache.add_order(order.clone(), None, None, false).unwrap();
        }

        let submit_order = SubmitOrder::new(
            order.trader_id(),
            None,
            order.strategy_id(),
            instrument_id,
            client_order_id,
            order.init_event().clone(),
            None,
            None,
            None,
            UUID4::new(),
            UnixNanos::default(),
            None,
        );
        node.process_exec_command(TradingCommandMessage::new(
            MessagingSwitchboard::risk_engine_execute(),
            TradingCommand::SubmitOrder(submit_order),
        ));

        advance_clock(Duration::from_millis(101)).await;
        let result = node.exec_manager.check_inflight_orders();
        let status = node
            .kernel
            .cache
            .borrow()
            .order(&client_order_id)
            .unwrap()
            .status();

        assert_eq!(status, OrderStatus::Initialized);
        assert_eq!(
            node.exec_manager.recon_check_retry_count(&client_order_id),
            0
        );
        assert!(result.events.is_empty());
        assert!(result.queries.is_empty());
    }

    #[rstest]
    #[cfg_attr(
        not(all(feature = "simulation", madsim)),
        tokio::test(start_paused = true)
    )]
    #[cfg_attr(all(feature = "simulation", madsim), madsim::test)]
    async fn test_risk_approved_command_registers_inflight() {
        let config = LiveNodeConfig {
            risk_engine: crate::config::LiveRiskEngineConfig {
                bypass: true,
                ..Default::default()
            },
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: true,
                inflight_check_threshold_ms: 100,
                inflight_check_retries: 2,
                ..Default::default()
            },
            ..Default::default()
        };
        let mut node = LiveNode::build("RiskApprovedNode".to_string(), Some(config)).unwrap();
        msgbus::register_trading_command_endpoint(
            MessagingSwitchboard::exec_engine_execute(),
            TypedIntoHandler::from(|_: TradingCommand| {}),
        );
        let instrument = crypto_perpetual_ethusdt();
        let instrument_id = instrument.id();
        let order = OrderTestBuilder::new(OrderType::Limit)
            .trader_id(node.trader_id())
            .strategy_id(StrategyId::from("S-RISK-APPROVED"))
            .instrument_id(instrument_id)
            .side(OrderSide::Buy)
            .quantity(Quantity::from("1.000"))
            .price(Price::from("100.00"))
            .build();
        let client_order_id = order.client_order_id();

        {
            let mut cache = node.kernel.cache.borrow_mut();
            cache
                .add_instrument(InstrumentAny::CryptoPerpetual(instrument))
                .unwrap();
            cache.add_order(order.clone(), None, None, false).unwrap();
        }

        let submit_order = SubmitOrder::new(
            order.trader_id(),
            None,
            order.strategy_id(),
            instrument_id,
            client_order_id,
            order.init_event().clone(),
            None,
            None,
            None,
            UUID4::new(),
            UnixNanos::default(),
            None,
        );
        node.process_exec_command(TradingCommandMessage::new(
            MessagingSwitchboard::risk_engine_execute(),
            TradingCommand::SubmitOrder(submit_order),
        ));

        advance_clock(Duration::from_millis(101)).await;
        let result = node.exec_manager.check_inflight_orders();
        let [TradingCommand::QueryOrder(query)] = result.queries.as_slice() else {
            panic!("expected one query order command");
        };

        assert_eq!(query.client_order_id, client_order_id);
        assert_eq!(
            node.exec_manager.recon_check_retry_count(&client_order_id),
            1
        );
        assert!(result.events.is_empty());
    }

    #[rstest]
    fn test_live_node_builder_clock_factory_drives_kernel_clock() {
        let calls = Rc::new(Cell::new(0usize));
        let calls_in_factory = calls.clone();
        let sentinel = UnixNanos::from(123_456_789_u64);

        let node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .with_clock_factory(move || {
                calls_in_factory.set(calls_in_factory.get() + 1);
                let mut clock = TestClock::new();
                clock.advance_time(sentinel, true);
                Rc::new(RefCell::new(clock)) as Rc<RefCell<dyn Clock>>
            })
            .build()
            .unwrap();

        assert_eq!(node.kernel().clock().borrow().timestamp_ns(), sentinel);
        assert_eq!(calls.get(), 1);
    }

    #[derive(Debug)]
    struct ReplayKernelEventStore {
        fail_restore: bool,
    }

    impl KernelEventStore for ReplayKernelEventStore {
        fn restore_parent_cache(
            &mut self,
            _instance_id: UUID4,
            _cache: &mut Cache,
        ) -> anyhow::Result<()> {
            if self.fail_restore {
                anyhow::bail!("replay restore failed");
            }

            Ok(())
        }

        fn open(
            &mut self,
            _instance_id: UUID4,
            _components: &RegisteredComponents,
            _environment: Environment,
        ) -> anyhow::Result<()> {
            Ok(())
        }

        fn snapshot_anchorer(&self) -> Option<SnapshotAnchorer> {
            None
        }

        fn seal(&mut self, _ts_init: UnixNanos) {}

        fn run_id(&self) -> Option<&str> {
            Some("replay-child")
        }

        fn parent_run_id(&self) -> Option<&str> {
            Some("seed-run")
        }

        fn is_event_store_replay_configured(&self) -> bool {
            true
        }

        fn is_halted(&self) -> bool {
            false
        }
    }

    #[derive(Debug)]
    struct TestStrategy {
        core: StrategyCore,
    }

    impl TestStrategy {
        fn new(config: StrategyConfig) -> Self {
            Self {
                core: StrategyCore::new(config),
            }
        }
    }

    impl DataActor for TestStrategy {}

    nautilus_strategy!(TestStrategy, {
        fn external_order_claims(&self) -> Option<Vec<InstrumentId>> {
            self.core.config.external_order_claims.clone()
        }
    });

    fn live_node_with_replay_store(fail_restore: bool) -> LiveNode {
        // load_state must be true: the kernel rejects event-store replay otherwise,
        // and LiveNodeConfig defaults it to false.
        let builder = LiveNodeBuilder::new(TraderId::default(), Environment::Live)
            .unwrap()
            .with_exec_engine_config(crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            })
            .with_load_state(true)
            .with_name("TestKernel")
            .with_event_store(move |_instance_id: UUID4, _clock: Rc<RefCell<dyn Clock>>| {
                Ok(Box::new(ReplayKernelEventStore { fail_restore }) as Box<dyn KernelEventStore>)
            });

        builder.build().unwrap()
    }

    #[rstest]
    fn test_add_strategy_registers_external_order_claims_with_manager_and_engine() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .with_delay_post_stop_secs(0)
            .with_timeout_connection(1)
            .build()
            .unwrap();
        let instrument_id = InstrumentId::from("AUDUSD.SIM");
        let strategy_id = StrategyId::from("CLAIMS-001");

        node.add_strategy(TestStrategy::new(StrategyConfig {
            strategy_id: Some(strategy_id),
            external_order_claims: Some(vec![instrument_id]),
            ..Default::default()
        }))
        .unwrap();

        assert_eq!(
            node.exec_manager.get_external_order_claim(&instrument_id),
            Some(strategy_id)
        );

        {
            let exec_engine = node.kernel().exec_engine.borrow();
            assert_eq!(
                exec_engine.get_external_order_claim(&instrument_id),
                Some(strategy_id)
            );
        }
    }

    #[rstest]
    fn test_register_external_order_claims_after_build_reaches_both_tiers() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .build()
            .unwrap();
        let instrument_id = InstrumentId::from("AUDUSD.SIM");
        let strategy_id = StrategyId::from("CLAIMS-001");

        node.register_external_order_claims(strategy_id, &[instrument_id])
            .unwrap();

        assert_eq!(
            node.exec_manager.get_external_order_claim(&instrument_id),
            Some(strategy_id)
        );
        assert_eq!(
            node.kernel
                .exec_engine
                .borrow()
                .get_external_order_claim(&instrument_id),
            Some(strategy_id)
        );
    }

    #[rstest]
    #[tokio::test]
    async fn test_register_external_order_claims_while_running_reaches_both_tiers() {
        let mut node = live_node_with_replay_store(false);
        let instrument_id = InstrumentId::from("AUDUSD.SIM");
        let strategy_id = StrategyId::from("CLAIMS-001");

        node.start().await.unwrap();
        assert_eq!(node.state(), NodeState::Running);

        node.register_external_order_claims(strategy_id, &[instrument_id])
            .unwrap();

        assert_eq!(
            node.exec_manager.get_external_order_claim(&instrument_id),
            Some(strategy_id)
        );
        assert_eq!(
            node.kernel
                .exec_engine
                .borrow()
                .get_external_order_claim(&instrument_id),
            Some(strategy_id)
        );
    }

    #[rstest]
    fn test_register_external_order_claims_conflicting_batch_leaves_new_claims_absent() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .build()
            .unwrap();
        let existing_instrument = InstrumentId::from("AUDUSD.SIM");
        let new_instruments = [
            InstrumentId::from("EURUSD.SIM"),
            InstrumentId::from("GBPUSD.SIM"),
        ];
        let existing_strategy_id = StrategyId::from("CLAIMS-001");
        let new_strategy_id = StrategyId::from("CLAIMS-002");
        node.register_external_order_claims(existing_strategy_id, &[existing_instrument])
            .unwrap();

        let result = node.register_external_order_claims(
            new_strategy_id,
            &[new_instruments[0], existing_instrument, new_instruments[1]],
        );

        assert!(result.is_err());
        assert_eq!(
            node.exec_manager
                .get_external_order_claim(&existing_instrument),
            Some(existing_strategy_id)
        );

        for instrument_id in new_instruments {
            assert_eq!(
                node.exec_manager.get_external_order_claim(&instrument_id),
                None
            );
            assert_eq!(
                node.kernel
                    .exec_engine
                    .borrow()
                    .get_external_order_claim(&instrument_id),
                None
            );
        }
    }

    #[rstest]
    fn test_register_external_order_claims_one_tier_conflict_changes_neither_tier() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .build()
            .unwrap();
        let conflicting_instrument = InstrumentId::from("AUDUSD.SIM");
        let new_instrument = InstrumentId::from("EURUSD.SIM");
        let existing_strategy_id = StrategyId::from("CLAIMS-001");
        let new_strategy_id = StrategyId::from("CLAIMS-002");
        node.exec_manager
            .claim_external_orders(conflicting_instrument, existing_strategy_id)
            .unwrap();

        let result = node.register_external_order_claims(
            new_strategy_id,
            &[new_instrument, conflicting_instrument],
        );

        assert!(result.is_err());
        assert_eq!(
            node.exec_manager
                .get_external_order_claim(&conflicting_instrument),
            Some(existing_strategy_id)
        );
        assert_eq!(
            node.kernel
                .exec_engine
                .borrow()
                .get_external_order_claim(&conflicting_instrument),
            None
        );
        assert_eq!(
            node.exec_manager.get_external_order_claim(&new_instrument),
            None
        );
        assert_eq!(
            node.kernel
                .exec_engine
                .borrow()
                .get_external_order_claim(&new_instrument),
            None
        );
    }

    #[rstest]
    fn test_register_external_order_claims_engine_only_conflict_changes_neither_tier() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .build()
            .unwrap();
        let conflicting_instrument = InstrumentId::from("AUDUSD.SIM");
        let new_instrument = InstrumentId::from("EURUSD.SIM");
        let existing_strategy_id = StrategyId::from("CLAIMS-001");
        let new_strategy_id = StrategyId::from("CLAIMS-002");

        // Seed the conflict on the engine tier only, mirroring the manager-only case.
        node.kernel
            .exec_engine
            .borrow_mut()
            .register_external_order_claims(
                existing_strategy_id,
                &HashSet::from([conflicting_instrument]),
            )
            .unwrap();

        let result = node.register_external_order_claims(
            new_strategy_id,
            &[new_instrument, conflicting_instrument],
        );

        assert!(result.is_err());
        assert_eq!(
            node.kernel
                .exec_engine
                .borrow()
                .get_external_order_claim(&conflicting_instrument),
            Some(existing_strategy_id)
        );
        assert_eq!(
            node.exec_manager
                .get_external_order_claim(&conflicting_instrument),
            None
        );
        assert_eq!(
            node.kernel
                .exec_engine
                .borrow()
                .get_external_order_claim(&new_instrument),
            None
        );
        assert_eq!(
            node.exec_manager.get_external_order_claim(&new_instrument),
            None
        );
    }

    #[rstest]
    fn test_deregister_external_order_claims_allows_successor_to_claim() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .build()
            .unwrap();
        let instruments = [
            InstrumentId::from("AUDUSD.SIM"),
            InstrumentId::from("EURUSD.SIM"),
        ];
        let first_strategy_id = StrategyId::from("CLAIMS-001");
        let successor_strategy_id = StrategyId::from("CLAIMS-002");
        node.register_external_order_claims(first_strategy_id, &instruments)
            .unwrap();

        node.deregister_external_order_claims(first_strategy_id)
            .unwrap();
        node.register_external_order_claims(successor_strategy_id, &instruments)
            .unwrap();

        for instrument_id in instruments {
            assert_eq!(
                node.exec_manager.get_external_order_claim(&instrument_id),
                Some(successor_strategy_id)
            );
            assert_eq!(
                node.kernel
                    .exec_engine
                    .borrow()
                    .get_external_order_claim(&instrument_id),
                Some(successor_strategy_id)
            );
        }
    }

    #[rstest]
    fn test_deregister_external_order_claims_divergence_changes_neither_tier() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .build()
            .unwrap();
        let manager_instrument = InstrumentId::from("AUDUSD.SIM");
        let engine_instrument = InstrumentId::from("EURUSD.SIM");
        let strategy_id = StrategyId::from("CLAIMS-001");
        node.exec_manager
            .claim_external_orders(manager_instrument, strategy_id)
            .unwrap();
        node.kernel
            .exec_engine
            .borrow_mut()
            .register_external_order_claims(strategy_id, &HashSet::from([engine_instrument]))
            .unwrap();

        let result = node.deregister_external_order_claims(strategy_id);

        assert!(result.is_err());
        assert_eq!(
            node.exec_manager
                .get_external_order_claim(&manager_instrument),
            Some(strategy_id)
        );
        assert_eq!(
            node.kernel
                .exec_engine
                .borrow()
                .get_external_order_claim(&engine_instrument),
            Some(strategy_id)
        );
    }

    #[rstest]
    fn test_deregister_external_order_claims_without_claims_is_idempotent() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .build()
            .unwrap();
        let strategy_id = StrategyId::from("CLAIMS-001");

        node.deregister_external_order_claims(strategy_id).unwrap();
        node.deregister_external_order_claims(strategy_id).unwrap();
    }

    #[rstest]
    fn test_add_strategy_rejects_duplicate_external_order_claim_without_overwriting() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .with_delay_post_stop_secs(0)
            .with_timeout_connection(1)
            .build()
            .unwrap();
        let instrument_id = InstrumentId::from("AUDUSD.SIM");
        let strategy_id = StrategyId::from("CLAIMS-001");
        let duplicate_strategy_id = StrategyId::from("OTHER-002");

        node.add_strategy(TestStrategy::new(StrategyConfig {
            strategy_id: Some(strategy_id),
            external_order_claims: Some(vec![instrument_id]),
            ..Default::default()
        }))
        .unwrap();

        let result = node.add_strategy(TestStrategy::new(StrategyConfig {
            strategy_id: Some(duplicate_strategy_id),
            external_order_claims: Some(vec![instrument_id]),
            ..Default::default()
        }));

        assert!(result.is_err());
        assert!(
            result
                .unwrap_err()
                .to_string()
                .contains("already exists for CLAIMS-001")
        );
        assert_eq!(
            node.exec_manager.get_external_order_claim(&instrument_id),
            Some(strategy_id)
        );

        {
            let exec_engine = node.kernel().exec_engine.borrow();
            assert_eq!(
                exec_engine.get_external_order_claim(&instrument_id),
                Some(strategy_id)
            );
        }
    }

    #[rstest]
    fn test_add_strategy_rejects_repeated_external_order_claim_without_registering() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .with_delay_post_stop_secs(0)
            .with_timeout_connection(1)
            .build()
            .unwrap();
        let instrument_id = InstrumentId::from("AUDUSD.SIM");
        let strategy_id = StrategyId::from("CLAIMS-001");

        let result = node.add_strategy(TestStrategy::new(StrategyConfig {
            strategy_id: Some(strategy_id),
            external_order_claims: Some(vec![instrument_id, instrument_id]),
            ..Default::default()
        }));

        assert!(result.is_err());
        assert!(
            result
                .unwrap_err()
                .to_string()
                .contains("already exists for CLAIMS-001")
        );
        assert_eq!(
            node.exec_manager.get_external_order_claim(&instrument_id),
            None
        );

        {
            let exec_engine = node.kernel().exec_engine.borrow();
            assert_eq!(exec_engine.get_external_order_claim(&instrument_id), None);
        }
    }

    #[rstest]
    fn test_add_strategy_failure_does_not_register_external_order_claims() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .with_delay_post_stop_secs(0)
            .with_timeout_connection(1)
            .build()
            .unwrap();
        let instrument_id = InstrumentId::from("AUDUSD.SIM");
        let strategy_id = StrategyId::from("CLAIMS-001");
        let mut strategy = TestStrategy::new(StrategyConfig {
            strategy_id: Some(strategy_id),
            external_order_claims: Some(vec![instrument_id]),
            ..Default::default()
        });

        strategy
            .core
            .register(
                node.trader_id(),
                node.kernel.clock(),
                node.kernel.cache.clone(),
                node.kernel.portfolio.clone(),
            )
            .unwrap();

        let result = node.add_strategy(strategy);

        assert!(result.is_err());
        assert!(
            result
                .unwrap_err()
                .to_string()
                .contains("already registered with trader")
        );
        assert_eq!(
            node.exec_manager.get_external_order_claim(&instrument_id),
            None
        );
        assert_eq!(
            node.kernel
                .exec_engine
                .borrow()
                .get_external_order_claim(&instrument_id),
            None
        );
    }

    #[rstest]
    fn test_add_strategy_without_claims_or_oms_type_does_not_require_engine_borrow() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .build()
            .unwrap();
        let exec_engine = node.kernel.exec_engine.clone();
        let _engine_borrow = exec_engine.borrow_mut();

        node.add_strategy(TestStrategy::new(StrategyConfig {
            strategy_id: Some(StrategyId::from("NOCLAIMS-001")),
            ..Default::default()
        }))
        .unwrap();
    }

    #[rstest]
    fn test_add_strategy_registers_configured_hedging_oms_type() {
        let mut node = LiveNode::builder(TraderId::from("TESTER-001"), Environment::Sandbox)
            .unwrap()
            .with_reconciliation(false)
            .with_delay_post_stop_secs(0)
            .with_timeout_connection(1)
            .build()
            .unwrap();
        let strategy_id = StrategyId::from("FUNDING_ARBITRAGE-001");

        node.add_strategy(TestStrategy::new(StrategyConfig {
            strategy_id: Some(strategy_id),
            oms_type: Some(OmsType::Hedging),
            ..Default::default()
        }))
        .unwrap();

        let instrument = crypto_perpetual_ethusdt();
        let instrument_id = instrument.id();
        let client_id = ClientId::from("STUB");

        node.kernel
            .cache
            .borrow_mut()
            .add_instrument(InstrumentAny::CryptoPerpetual(instrument))
            .unwrap();
        node.kernel
            .exec_engine
            .borrow_mut()
            .register_client(Box::new(StubExecutionClient::new(
                client_id,
                AccountId::from("TEST-ACCOUNT"),
                instrument_id.venue,
                OmsType::Netting,
                None,
            )))
            .unwrap();

        let order = OrderTestBuilder::new(OrderType::Market)
            .trader_id(node.trader_id())
            .strategy_id(strategy_id)
            .instrument_id(instrument_id)
            .quantity(Quantity::from("1.000"))
            .build();
        let position_id = PositionId::new("CUSTOM-POSITION-001");

        node.kernel
            .cache
            .borrow_mut()
            .add_order(order.clone(), Some(position_id), Some(client_id), true)
            .unwrap();

        let submit_order = SubmitOrder::new(
            order.trader_id(),
            Some(client_id),
            strategy_id,
            instrument_id,
            order.client_order_id(),
            order.init_event().clone(),
            order.exec_algorithm_id(),
            Some(position_id),
            None,
            UUID4::new(),
            UnixNanos::default(),
            None,
        );

        node.kernel
            .exec_engine
            .borrow()
            .execute(TradingCommand::SubmitOrder(submit_order));

        let exec_engine = node.kernel.exec_engine.borrow();
        let cache = exec_engine.cache().borrow();
        let cached_order = cache
            .order(&order.client_order_id())
            .expect("Order should be cached");

        assert_eq!(cached_order.status(), OrderStatus::Initialized);
    }

    #[cfg(all(feature = "simulation", madsim))]
    async fn advance_clock(d: Duration) {
        madsim::time::advance(d);
        madsim::task::yield_now().await;
    }

    #[cfg(not(all(feature = "simulation", madsim)))]
    async fn advance_clock(d: Duration) {
        tokio::time::advance(d).await;
    }

    #[cfg_attr(
        not(all(feature = "simulation", madsim)),
        tokio::test(start_paused = true)
    )]
    #[cfg_attr(all(feature = "simulation", madsim), madsim::test)]
    async fn test_reconciliation_check_due_uses_monotonic_elapsed_time() {
        let last = dst::time::Instant::now();
        let interval = Duration::from_millis(100);

        assert!(!reconciliation_check_due(last, last, Duration::ZERO));
        assert!(!reconciliation_check_due(last, last, interval));

        advance_clock(Duration::from_millis(99)).await;
        let before_interval = dst::time::Instant::now();
        assert!(!reconciliation_check_due(before_interval, last, interval));

        advance_clock(Duration::from_millis(1)).await;
        let at_interval = dst::time::Instant::now();
        assert!(reconciliation_check_due(at_interval, last, interval));

        assert!(!reconciliation_check_due(last, at_interval, interval));
    }

    #[cfg_attr(
        not(all(feature = "simulation", madsim)),
        tokio::test(start_paused = true)
    )]
    #[cfg_attr(all(feature = "simulation", madsim), madsim::test)]
    async fn test_run_reconciliation_checks_does_not_publish_open_order_queries() {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: true,
                open_check_interval_secs: Some(1.0),
                position_check_interval_secs: Some(1.0),
                max_single_order_queries_per_cycle: 5,
                ..Default::default()
            },
            ..Default::default()
        };
        let mut node =
            LiveNode::build("ReconciliationFallbackNode".to_string(), Some(config)).unwrap();
        let client_id = ClientId::from("TEST-QUERY");
        let account_id = AccountId::from("TEST-QUERY-001");

        let trading_commands = Rc::new(RefCell::new(Vec::new()));
        msgbus::register_trading_command_endpoint(
            MessagingSwitchboard::exec_engine_execute(),
            TypedIntoHandler::from({
                let trading_commands = trading_commands.clone();
                move |command: TradingCommand| {
                    trading_commands.borrow_mut().push(command);
                }
            }),
        );

        let venue_order_id = VenueOrderId::from("V-NODE-QUERY-001");
        let instrument = crypto_perpetual_ethusdt();
        let instrument_id = instrument.id();
        let client_order_id = ClientOrderId::from("O-NODE-QUERY-001");

        node.kernel
            .cache
            .borrow_mut()
            .add_instrument(InstrumentAny::CryptoPerpetual(instrument))
            .unwrap();
        insert_accepted_limit_order_in_node(
            &node,
            account_id,
            client_id,
            instrument_id,
            client_order_id,
            venue_order_id,
        );

        let last = dst::time::Instant::now();
        advance_clock(Duration::from_nanos(1)).await;
        let now = dst::time::Instant::now();
        let mut last_inflight_check = last;
        let mut last_open_check = last;
        let mut last_position_check = last;
        let mut open_order_report_task = None;
        let mut targeted_order_report_task = None;
        let mut position_report_task = None;

        node.run_reconciliation_checks(
            now,
            ReconciliationCheckIntervals {
                inflight: Duration::ZERO,
                open: Duration::from_nanos(1),
                position: Duration::ZERO,
            },
            &mut ReconciliationCheckState {
                last_inflight_check: &mut last_inflight_check,
                last_open_check: &mut last_open_check,
                last_position_check: &mut last_position_check,
                open_order_report_task: &mut open_order_report_task,
                targeted_order_report_task: &mut targeted_order_report_task,
                position_report_task: &mut position_report_task,
            },
        );

        let commands = trading_commands.borrow();

        assert!(commands.is_empty());
        assert!(open_order_report_task.is_none());
        assert!(targeted_order_report_task.is_none());
        assert!(position_report_task.is_none());

        ExecutionEngine::register_msgbus_handlers(&node.kernel.exec_engine);
    }

    fn insert_accepted_limit_order_in_node(
        node: &LiveNode,
        account_id: AccountId,
        client_id: ClientId,
        instrument_id: InstrumentId,
        client_order_id: ClientOrderId,
        venue_order_id: VenueOrderId,
    ) {
        let order = OrderTestBuilder::new(OrderType::Limit)
            .client_order_id(client_order_id)
            .instrument_id(instrument_id)
            .quantity(Quantity::from("10.0"))
            .price(Price::from("100.0"))
            .build();
        let submitted = TestOrderEventStubs::submitted(&order, account_id);
        node.kernel
            .cache
            .borrow_mut()
            .add_order(order, None, Some(client_id), false)
            .unwrap();
        let order = node
            .kernel
            .cache
            .borrow_mut()
            .update_order(&submitted)
            .unwrap();
        let accepted = TestOrderEventStubs::accepted(&order, account_id, venue_order_id);
        node.kernel
            .cache
            .borrow_mut()
            .update_order(&accepted)
            .unwrap();
    }

    fn recent_fill_test_fixture(name: &str) -> (LiveNode, OrderEventAny, InstrumentAny) {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: true,
                ..Default::default()
            },
            ..Default::default()
        };
        let node = LiveNode::build(name.to_string(), Some(config)).unwrap();
        let account_id = AccountId::from("TEST-001");
        let client_id = ClientId::from("TEST-RECENT-FILL");
        let client_order_id = ClientOrderId::from("O-RECENT-FILL");
        let venue_order_id = VenueOrderId::from("V-RECENT-FILL");
        let instrument = InstrumentAny::CryptoPerpetual(crypto_perpetual_ethusdt());
        node.kernel
            .cache
            .borrow_mut()
            .add_instrument(instrument.clone())
            .unwrap();
        insert_accepted_limit_order_in_node(
            &node,
            account_id,
            client_id,
            instrument.id(),
            client_order_id,
            venue_order_id,
        );
        let order = node
            .kernel
            .cache
            .borrow()
            .order_owned(&client_order_id)
            .unwrap();
        let fill = TestOrderEventStubs::filled(
            &order,
            &instrument,
            Some(TradeId::from("T-RECENT-FILL")),
            None,
            Some(Price::from("100.0")),
            Some(Quantity::from("1.0")),
            Some(LiquiditySide::Taker),
            None,
            None,
            Some(account_id),
        );

        (node, fill, instrument)
    }

    fn fill_report_event(fill: &OrderFilled) -> ExecutionEvent {
        ExecutionEvent::Report(ExecutionReport::Fill(Box::new(FillReport::new(
            fill.account_id,
            fill.instrument_id,
            fill.venue_order_id,
            fill.trade_id,
            fill.order_side,
            fill.last_qty,
            fill.last_px,
            fill.commission
                .unwrap_or_else(|| Money::zero(fill.currency)),
            fill.liquidity_side,
            Some(fill.client_order_id),
            fill.position_id,
            fill.ts_event,
            fill.ts_init,
            None,
        ))))
    }

    fn is_recent_fill(node: &LiveNode, fill: &OrderFilled) -> bool {
        node.exec_manager.is_fill_recently_processed(
            fill.account_id,
            fill.instrument_id,
            fill.trade_id,
        )
    }

    #[rstest]
    #[case(0, NodeState::Idle)]
    #[case(1, NodeState::Starting)]
    #[case(2, NodeState::Running)]
    #[case(3, NodeState::ShuttingDown)]
    #[case(4, NodeState::Stopped)]
    fn test_node_state_from_u8_valid(#[case] value: u8, #[case] expected: NodeState) {
        assert_eq!(NodeState::from_u8(value), expected);
    }

    #[rstest]
    #[case(5)]
    #[case(255)]
    #[should_panic(expected = "Invalid NodeState value")]
    fn test_node_state_from_u8_invalid_panics(#[case] value: u8) {
        let _ = NodeState::from_u8(value);
    }

    #[rstest]
    fn test_node_state_roundtrip() {
        for state in [
            NodeState::Idle,
            NodeState::Starting,
            NodeState::Running,
            NodeState::ShuttingDown,
            NodeState::Stopped,
        ] {
            assert_eq!(NodeState::from_u8(state.as_u8()), state);
        }
    }

    #[rstest]
    fn test_node_state_is_running_only_for_running() {
        assert!(!NodeState::Idle.is_running());
        assert!(!NodeState::Starting.is_running());
        assert!(NodeState::Running.is_running());
        assert!(!NodeState::ShuttingDown.is_running());
        assert!(!NodeState::Stopped.is_running());
    }

    #[rstest]
    #[tokio::test]
    async fn test_await_engines_connected_returns_stop_requested() {
        let node = LiveNode::build("TestNode".to_string(), None).unwrap();
        let handle = node.handle();

        handle.stop();

        let deadline = dst::time::Instant::now() + Duration::from_secs(1);
        let status = node.await_engines_connected(deadline).await;

        assert_eq!(status, EngineConnectionStatus::StopRequested);
        assert!(handle.should_stop());
    }

    #[rstest]
    #[tokio::test]
    async fn test_await_engines_connected_returns_shutdown_requested() {
        let node = LiveNode::build("TestNode".to_string(), None).unwrap();

        node.kernel().shutdown_flag().set(true);

        let deadline = dst::time::Instant::now() + Duration::from_secs(1);
        let status = node.await_engines_connected(deadline).await;

        assert_eq!(status, EngineConnectionStatus::ShutdownRequested);
    }

    #[rstest]
    #[tokio::test]
    async fn test_start_stop_request_aborts_startup_without_running() {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            timeout_disconnection: Duration::from_millis(50),
            ..Default::default()
        };
        let mut node = LiveNode::build("TestNode".to_string(), Some(config)).unwrap();
        let handle = node.handle();

        handle.stop();
        node.start().await.unwrap();

        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(handle.should_stop());
        assert!(!handle.is_running());
    }

    #[rstest]
    #[tokio::test(start_paused = true)]
    async fn test_stop_processes_residual_exec_event_during_grace_period() {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            timeout_connection: Duration::ZERO,
            timeout_reconciliation: Duration::ZERO,
            timeout_portfolio: Duration::ZERO,
            timeout_disconnection: Duration::ZERO,
            delay_post_stop: Duration::from_millis(20),
            timeout_shutdown: Duration::ZERO,
            ..Default::default()
        };
        let mut node = LiveNode::build("TestNode".to_string(), Some(config)).unwrap();
        let order = OrderTestBuilder::new(OrderType::Market)
            .instrument_id(InstrumentId::from("EUR/USD.SIM"))
            .quantity(Quantity::from("2"))
            .build();
        let client_order_id = order.client_order_id();
        let submitted = TestOrderEventStubs::submitted(&order, AccountId::from("POLL-STOP-001"));

        node.kernel
            .cache()
            .borrow_mut()
            .add_order(order, None, None, false)
            .unwrap();

        node.start().await.unwrap();
        let exec_event_sender = get_exec_event_sender();

        let send_residual = tokio::spawn(async move {
            tokio::time::sleep(Duration::from_millis(1)).await;
            exec_event_sender
                .send(ExecutionEvent::Order(submitted))
                .unwrap();
        });

        node.stop().await.unwrap();
        send_residual.await.unwrap();

        assert_eq!(
            node.kernel
                .cache()
                .borrow()
                .order(&client_order_id)
                .unwrap()
                .status(),
            OrderStatus::Submitted
        );

        node.dispose();
    }

    #[rstest]
    #[tokio::test]
    async fn test_live_state_persistence_loads_before_start_and_saves_after_stop() {
        let actor_id = ActorId::from("LIVE-STATE-ACTOR");
        let strategy_id = StrategyId::from("LIVE-STATE-STRATEGY-001");
        let actor_load = IndexMap::from([("actor-load".to_string(), b"actor-loaded".to_vec())]);
        let strategy_load =
            IndexMap::from([("strategy-load".to_string(), b"strategy-loaded".to_vec())]);
        let actor_save = IndexMap::from([("actor-save".to_string(), b"actor-saved".to_vec())]);
        let strategy_save =
            IndexMap::from([("strategy-save".to_string(), b"strategy-saved".to_vec())]);
        let (database, control) = TestCacheDatabaseControl::create();
        control.set_actor_state(actor_id, &actor_load);
        control.set_strategy_state(strategy_id, &strategy_load);
        let config = LiveNodeConfig {
            load_state: true,
            save_state: true,
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            timeout_connection: Duration::ZERO,
            timeout_reconciliation: Duration::ZERO,
            timeout_portfolio: Duration::ZERO,
            timeout_disconnection: Duration::ZERO,
            delay_post_stop: Duration::ZERO,
            timeout_shutdown: Duration::ZERO,
            ..Default::default()
        };
        let mut node = LiveNode::build("StatePersistenceNode".to_string(), Some(config)).unwrap();
        node.set_cache_database(Box::new(database)).unwrap();
        node.add_actor(StateActor::new(
            actor_id,
            control.clone(),
            actor_save.clone(),
        ))
        .unwrap();
        node.add_strategy(StateStrategy::new(
            strategy_id,
            control.clone(),
            strategy_save.clone(),
        ))
        .unwrap();

        node.start().await.unwrap();
        node.stop().await.unwrap();
        node.dispose();

        assert_eq!(
            control.events(),
            vec![
                "actor.load:LIVE-STATE-ACTOR",
                "actor.on_load",
                "strategy.load:LIVE-STATE-STRATEGY-001",
                "strategy.on_load",
                "actor.on_start",
                "strategy.on_start",
                "actor.on_stop",
                "strategy.on_stop",
                "actor.on_save",
                "actor.update:LIVE-STATE-ACTOR",
                "strategy.on_save",
                "strategy.update:LIVE-STATE-STRATEGY-001",
                "database.close",
            ]
        );
        assert_eq!(control.actor_state(&actor_id), Some(actor_save));
        assert_eq!(control.strategy_state(&strategy_id), Some(strategy_save));
        assert_eq!(node.state(), NodeState::Stopped);
    }

    #[rstest]
    #[tokio::test]
    async fn test_live_state_persistence_reports_callback_errors_after_shutdown() {
        let actor_id = ActorId::from("LIVE-FAIL-SAVE-ACTOR");
        let strategy_id = StrategyId::from("LIVE-FAIL-SAVE-STRATEGY-001");
        let (database, control) = TestCacheDatabaseControl::create();
        let config = LiveNodeConfig {
            save_state: true,
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            timeout_connection: Duration::ZERO,
            timeout_reconciliation: Duration::ZERO,
            timeout_portfolio: Duration::ZERO,
            timeout_disconnection: Duration::ZERO,
            delay_post_stop: Duration::ZERO,
            timeout_shutdown: Duration::ZERO,
            ..Default::default()
        };
        let mut node =
            LiveNode::build("StatePersistenceErrorNode".to_string(), Some(config)).unwrap();
        node.set_cache_database(Box::new(database)).unwrap();
        node.add_actor(
            StateActor::new(actor_id, control.clone(), IndexMap::new()).with_fail_save(),
        )
        .unwrap();
        node.add_strategy(
            StateStrategy::new(strategy_id, control.clone(), IndexMap::new()).with_fail_save(),
        )
        .unwrap();

        node.start().await.unwrap();
        let error = node.stop().await.unwrap_err();
        node.dispose();

        assert_eq!(
            error.to_string(),
            "failed while finalizing kernel shutdown: Failed to save component state: actor \
             LIVE-FAIL-SAVE-ACTOR callback: test actor on_save failure; strategy \
             LIVE-FAIL-SAVE-STRATEGY-001 callback: test strategy on_save failure"
        );
        assert_eq!(
            control.events(),
            vec![
                "actor.on_start",
                "strategy.on_start",
                "actor.on_stop",
                "strategy.on_stop",
                "actor.on_save",
                "strategy.on_save",
                "database.close",
            ]
        );
        assert_eq!(node.state(), NodeState::Stopped);
    }

    #[rstest]
    #[tokio::test]
    async fn test_stop_drains_queued_exec_event_after_zero_grace() {
        let config = LiveNodeConfig {
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            timeout_connection: Duration::ZERO,
            timeout_reconciliation: Duration::ZERO,
            timeout_portfolio: Duration::ZERO,
            timeout_disconnection: Duration::ZERO,
            delay_post_stop: Duration::ZERO,
            timeout_shutdown: Duration::ZERO,
            ..Default::default()
        };
        let mut node = LiveNode::build("TestNode".to_string(), Some(config)).unwrap();
        let order = OrderTestBuilder::new(OrderType::Market)
            .instrument_id(InstrumentId::from("GBP/USD.SIM"))
            .quantity(Quantity::from("3"))
            .build();
        let client_order_id = order.client_order_id();
        let submitted = TestOrderEventStubs::submitted(&order, AccountId::from("POLL-DRAIN-001"));

        node.kernel
            .cache()
            .borrow_mut()
            .add_order(order, None, None, false)
            .unwrap();

        node.start().await.unwrap();
        get_exec_event_sender()
            .send(ExecutionEvent::Order(submitted))
            .unwrap();

        node.stop().await.unwrap();

        assert_eq!(
            node.kernel
                .cache()
                .borrow()
                .order(&client_order_id)
                .unwrap()
                .status(),
            OrderStatus::Submitted
        );

        node.dispose();
    }

    #[rstest]
    #[tokio::test]
    async fn test_start_event_store_replay_skips_live_connections() {
        let mut node = live_node_with_replay_store(false);
        let handle = node.handle();

        node.start().await.unwrap();

        assert_eq!(handle.state(), NodeState::Running);
        assert!(handle.is_running());
        assert!(node.kernel.is_event_store_replay());
        assert!(node.runner.is_some());
    }

    #[rstest]
    #[tokio::test]
    async fn test_start_event_store_replay_preserves_stop_request() {
        let mut node = live_node_with_replay_store(false);
        let handle = node.handle();
        handle.stop();

        node.start().await.unwrap();

        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(handle.should_stop());
        assert!(node.kernel.is_event_store_replay());
        assert!(node.runner.is_some());
    }

    #[rstest]
    #[tokio::test]
    async fn test_start_event_store_replay_config_failure_aborts_startup() {
        let mut node = live_node_with_replay_store(true);
        let handle = node.handle();

        node.start().await.unwrap();

        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(!handle.is_running());
        assert!(node.kernel.is_event_store_replay_configured());
        assert!(!node.kernel.is_event_store_replay());
        assert!(node.runner.is_some());
    }

    #[rstest]
    #[tokio::test]
    async fn test_run_event_store_replay_consumes_runner_and_stops_before_connections() {
        let mut node = live_node_with_replay_store(false);
        let handle = node.handle();

        node.run().await.unwrap();

        assert_eq!(handle.state(), NodeState::Running);
        assert!(handle.is_running());
        assert!(node.kernel.is_event_store_replay());
        assert!(node.runner.is_none());
    }

    #[rstest]
    #[tokio::test]
    async fn test_run_event_store_replay_preserves_stop_request() {
        let mut node = live_node_with_replay_store(false);
        let handle = node.handle();
        handle.stop();

        node.run().await.unwrap();

        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(handle.should_stop());
        assert!(node.kernel.is_event_store_replay());
        assert!(node.runner.is_none());
    }

    #[rstest]
    #[tokio::test]
    async fn test_run_event_store_replay_config_failure_aborts_startup() {
        let mut node = live_node_with_replay_store(true);
        let handle = node.handle();

        node.run().await.unwrap();

        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(!handle.is_running());
        assert!(node.kernel.is_event_store_replay_configured());
        assert!(!node.kernel.is_event_store_replay());
        assert!(node.runner.is_none());
    }

    #[rstest]
    fn test_build_rejects_event_store_config_without_factory() {
        let config = LiveNodeConfig {
            event_store: Some(EventStoreConfig::default()),
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            ..Default::default()
        };

        let err = LiveNodeBuilder::from_config(config)
            .expect("builder")
            .build()
            .expect_err("should reject event_store config without factory");

        assert!(
            err.to_string().contains("with_event_store"),
            "error message should mention with_event_store, was: {err}"
        );
    }

    #[rstest]
    fn test_direct_build_rejects_event_store_config() {
        let config = LiveNodeConfig {
            event_store: Some(EventStoreConfig::default()),
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            ..Default::default()
        };

        let err = LiveNode::build("TestNode".to_string(), Some(config))
            .expect_err("LiveNode::build should reject event_store config");

        assert!(
            err.to_string().contains("with_event_store"),
            "error message should mention with_event_store, was: {err}"
        );
    }

    #[rstest]
    fn test_dispose_before_start_is_idempotent() {
        let mut node = LiveNode::build("TestNode".to_string(), None).unwrap();
        node.add_strategy(TestStrategy::new(StrategyConfig {
            strategy_id: Some(StrategyId::from("DISPOSAL-001")),
            ..Default::default()
        }))
        .unwrap();

        node.dispose();
        node.dispose();

        assert!(node.kernel.trader().borrow().is_disposed());
        assert_eq!(node.kernel.trader().borrow().component_count(), 0);
        assert_eq!(node.state(), NodeState::Stopped);
    }

    #[rstest]
    fn test_handle_initial_state() {
        let handle = LiveNodeHandle::new();

        assert_eq!(handle.state(), NodeState::Idle);
        assert!(!handle.should_stop());
        assert!(!handle.is_running());
    }

    #[rstest]
    fn test_handle_initial_metrics_snapshot_is_zero() {
        let handle = LiveNodeHandle::new();

        assert_eq!(handle.metrics_snapshot(), RunnerMetricsSnapshot::default());
    }

    #[rstest]
    fn test_record_runner_dispatch_updates_selected_channel() {
        let metrics = RunnerMetrics::default();
        let dispatch_start = dst::time::Instant::now();
        let metrics_start = dispatch_start
            .checked_sub(Duration::from_micros(1))
            .expect("test instant should support a one-microsecond lookback");

        record_runner_dispatch(
            &metrics,
            SystemChannel::DataCommands,
            dispatch_start,
            metrics_start,
        );
        let snapshot = metrics.snapshot();

        assert_eq!(snapshot.time_events.dispatched, 0);
        assert_eq!(snapshot.exec_events.dispatched, 0);
        assert_eq!(snapshot.exec_commands.dispatched, 0);
        assert_eq!(snapshot.data_events.dispatched, 0);
        assert_eq!(snapshot.data_commands.dispatched, 1);
        assert_eq!(
            snapshot.data_commands.last_dispatch_at_ns,
            snapshot.elapsed_ns
        );
        assert_eq!(
            snapshot.data_commands.dispatch_busy_ns,
            snapshot.dispatch_busy_ns
        );
        assert!(snapshot.dispatch_busy_ns < snapshot.elapsed_ns);
    }

    #[rstest]
    fn test_handle_stop_sets_flag() {
        let handle = LiveNodeHandle::new();

        handle.stop();

        assert!(handle.should_stop());
    }

    #[rstest]
    fn test_handle_stop_blocks_running_transition() {
        let handle = LiveNodeHandle::new();
        handle.set_starting();
        handle.stop();

        let transition = handle.try_set_running();

        assert_eq!(transition, RunningTransition::StopRequested);
        assert_eq!(handle.state(), NodeState::Starting);
        assert!(handle.should_stop());
        assert!(!handle.is_running());
    }

    #[rstest]
    fn test_handle_stop_after_running_transition_remains_pending() {
        let handle = LiveNodeHandle::new();
        handle.set_starting();

        let transition = handle.try_set_running();
        handle.stop();

        assert_eq!(transition, RunningTransition::Entered);
        assert_eq!(handle.state(), NodeState::Running);
        assert!(handle.should_stop());
        assert!(handle.is_running());
    }

    #[rstest]
    fn test_handle_node_state_transitions() {
        let handle = LiveNodeHandle::new();
        assert_eq!(handle.state(), NodeState::Idle);

        handle.set_starting();
        assert_eq!(handle.state(), NodeState::Starting);
        assert!(!handle.is_running());

        assert_eq!(handle.try_set_running(), RunningTransition::Entered);
        assert_eq!(handle.state(), NodeState::Running);
        assert!(handle.is_running());

        handle.set_shutting_down();
        assert_eq!(handle.state(), NodeState::ShuttingDown);
        assert!(!handle.is_running());

        handle.set_stopped();
        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(!handle.is_running());
    }

    #[rstest]
    fn test_handle_clone_shares_state_bidirectionally() {
        let handle1 = LiveNodeHandle::new();
        let handle2 = handle1.clone();

        handle1.set_starting();
        let transition = handle2.try_set_running();
        handle1.stop();

        assert_eq!(transition, RunningTransition::Entered);
        assert_eq!(handle1.state(), NodeState::Running);
        assert!(handle2.should_stop());
    }

    #[rstest]
    fn test_handle_stop_flag_survives_non_running_state_changes() {
        let handle = LiveNodeHandle::new();

        handle.set_starting();
        handle.stop();
        handle.set_shutting_down();
        handle.set_stopped();

        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(handle.should_stop());
    }

    #[rstest]
    fn test_builder_creation() {
        let result = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox);

        assert!(result.is_ok());
    }

    #[rstest]
    fn test_builder_rejects_backtest() {
        let result = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Backtest);

        assert!(result.is_err());
        assert!(result.unwrap_err().to_string().contains("Backtest"));
    }

    #[rstest]
    fn test_builder_accepts_live_environment() {
        let result = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Live);

        assert!(result.is_ok());
    }

    #[rstest]
    fn test_builder_accepts_sandbox_environment() {
        let result = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox);

        assert!(result.is_ok());
    }

    #[rstest]
    fn test_builder_fluent_api_chaining() {
        let builder = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Live)
            .unwrap()
            .with_name("TestNode")
            .with_instance_id(UUID4::new())
            .with_load_state(false)
            .with_save_state(true)
            .with_timeout_connection(30)
            .with_timeout_reconciliation(60)
            .with_reconciliation(true)
            .with_reconciliation_lookback_mins(120)
            .with_timeout_portfolio(10)
            .with_timeout_disconnection_secs(5)
            .with_delay_post_stop_secs(3)
            .with_delay_shutdown_secs(10);

        assert_eq!(builder.name(), "TestNode");
    }

    #[rstest]
    fn test_builder_with_external_msgbus_egress_uses_configured_encoding() {
        let (external_egress, publications, closed) = CapturingExternalEgress::new();
        let msgbus_config = MessageBusConfig {
            encoding: SerializationEncoding::Json,
            ..Default::default()
        };
        let node = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox)
            .unwrap()
            .with_msgbus_config(msgbus_config)
            .with_external_msgbus_egress(Box::new(external_egress))
            .build()
            .expect("node builds with external message bus egress");
        let quote = QuoteTick::default();

        msgbus::publish_quote("data.quotes.TEST".into(), &quote);

        let publications = publications.borrow();
        assert_eq!(publications.len(), 1);
        assert_eq!(publications[0].topic, "data.quotes.TEST");
        assert_eq!(
            serde_json::from_slice::<QuoteTick>(&publications[0].payload)
                .expect("JSON payload must decode as QuoteTick"),
            quote
        );
        drop(publications);

        msgbus::get_message_bus().borrow_mut().dispose();
        assert!(closed.get());
        drop(node);
    }

    #[rstest]
    #[tokio::test(flavor = "current_thread")]
    async fn test_builder_with_external_msgbus_factory_installs_egress_and_ingress() {
        let quote = QuoteTick::default();
        let (tx, rx) = tokio::sync::mpsc::channel::<BusMessage>(1);
        let publications = Arc::new(Mutex::new(Vec::new()));
        let closed = Arc::new(AtomicBool::new(false));
        let factory = CapturingBackingFactory::new(publications.clone(), closed.clone(), Some(rx));
        let msgbus_config = MessageBusConfig {
            external_streams: Some(vec!["stream".to_string()]),
            ..Default::default()
        };
        let config = LiveNodeConfig {
            environment: Environment::Sandbox,
            msgbus: Some(msgbus_config),
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            delay_post_stop: Duration::ZERO,
            timeout_connection: Duration::from_millis(500),
            timeout_disconnection: Duration::from_millis(500),
            ..Default::default()
        };
        let mut node = LiveNodeBuilder::from_config(config)
            .unwrap()
            .with_external_msgbus_factory(Box::new(factory))
            .build()
            .expect("node builds with external message bus factory");

        msgbus::publish_quote("data.quotes.TEST".into(), &quote);
        {
            let publications = publications.lock().unwrap();
            assert_eq!(publications.len(), 1);
            assert_eq!(publications[0].topic, "data.quotes.TEST");
            assert_eq!(
                serde_json::from_slice::<QuoteTick>(&publications[0].payload)
                    .expect("JSON payload must decode as QuoteTick"),
                quote
            );
        }

        let received = Rc::new(RefCell::new(Vec::<QuoteTick>::new()));
        let handle = node.handle();
        // Stopping from `drive` rather than here, so the node cannot finish `run` before the
        // republished quote is observed.
        let handler = TypedHandler::from({
            let received = received.clone();
            move |quote: &QuoteTick| {
                received.borrow_mut().push(*quote);
            }
        });
        msgbus::subscribe_quotes("data.quotes.*".into(), handler, None);
        msgbus::get_message_bus()
            .borrow_mut()
            .add_streaming_type(BusPayloadType::QuoteTick);

        let payload =
            Bytes::from(serde_json::to_vec(&quote).expect("QuoteTick should serialize as JSON"));
        let message = BusMessage::with_str_topic(
            "data.quotes.TEST",
            BusPayloadType::QuoteTick,
            payload,
            SerializationEncoding::Json,
        );

        tokio::time::timeout(Duration::from_secs(30), async {
            let run = node.run();
            tokio::pin!(run);

            let drive = async {
                wait_until_async(|| async { handle.is_running() }, Duration::from_secs(10)).await;

                tx.send(message)
                    .await
                    .expect("external ingress receiver should be open");

                wait_until_async(
                    || async { received.borrow().len() == 1 },
                    Duration::from_secs(10),
                )
                .await;
                assert_eq!(*received.borrow(), vec![quote]);
                handle.stop();
            };

            tokio::select! {
                biased;

                () = drive => {}
                result = &mut run => {
                    panic!("node stopped before factory ingress was republished: {result:?}");
                }
            }

            run.await.expect("node should stop cleanly");
        })
        .await
        .expect("live node should republish factory ingress and stop before timeout");

        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(closed.load(Ordering::Relaxed));
        msgbus::get_message_bus().borrow_mut().dispose();
    }

    #[rstest]
    #[tokio::test(flavor = "current_thread")]
    async fn test_builder_with_external_msgbus_factory_without_streams_runs_without_ingress() {
        let quote = QuoteTick::default();
        let publications = Arc::new(Mutex::new(Vec::new()));
        let closed = Arc::new(AtomicBool::new(false));
        let factory = CapturingBackingFactory::new(publications.clone(), closed.clone(), None);
        let config = LiveNodeConfig {
            environment: Environment::Sandbox,
            msgbus: Some(MessageBusConfig::default()),
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            delay_post_stop: Duration::ZERO,
            timeout_connection: Duration::from_millis(500),
            timeout_disconnection: Duration::from_millis(500),
            ..Default::default()
        };
        let mut node = LiveNodeBuilder::from_config(config)
            .unwrap()
            .with_external_msgbus_factory(Box::new(factory))
            .build()
            .expect("node builds with egress-only message bus factory");
        let handle = node.handle();

        msgbus::publish_quote("data.quotes.TEST".into(), &quote);
        {
            let publications = publications.lock().unwrap();
            assert_eq!(publications.len(), 1);
            assert_eq!(publications[0].topic, "data.quotes.TEST");
        }

        tokio::time::timeout(Duration::from_secs(30), async {
            let run = node.run();
            tokio::pin!(run);

            let drive = async {
                wait_until_async(|| async { handle.is_running() }, Duration::from_secs(10)).await;
                handle.stop();
            };

            tokio::select! {
                biased;

                () = drive => {}
                result = &mut run => {
                    panic!("node stopped before egress-only factory run was observed: {result:?}");
                }
            }

            run.await.expect("node should stop cleanly");
        })
        .await
        .expect("live node should run without external ingress before timeout");

        assert_eq!(handle.state(), NodeState::Stopped);
        msgbus::get_message_bus().borrow_mut().dispose();
        assert!(closed.load(Ordering::Relaxed));
    }

    #[rstest]
    fn test_builder_with_external_msgbus_factory_rejects_injected_surfaces() {
        let (external_egress, _publications, _closed) = CapturingExternalEgress::new();
        let egress_factory = CapturingBackingFactory::new(
            Arc::new(Mutex::new(Vec::new())),
            Arc::new(AtomicBool::new(false)),
            None,
        );
        let egress_error = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox)
            .unwrap()
            .with_external_msgbus_factory(Box::new(egress_factory))
            .with_external_msgbus_egress(Box::new(external_egress))
            .build()
            .expect_err("builder should reject factory plus injected egress");

        assert!(
            egress_error
                .to_string()
                .contains("cannot be combined with injected egress or ingress")
        );

        let (_tx, rx) = tokio::sync::mpsc::channel::<BusMessage>(1);
        let ingress_factory = CapturingBackingFactory::new(
            Arc::new(Mutex::new(Vec::new())),
            Arc::new(AtomicBool::new(false)),
            None,
        );
        let ingress = CapturingExternalIngress::new(rx, Rc::new(Cell::new(false)));
        let ingress_error = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox)
            .unwrap()
            .with_external_msgbus_factory(Box::new(ingress_factory))
            .with_external_ingress(Box::new(ingress))
            .build()
            .expect_err("builder should reject factory plus injected ingress");

        assert!(
            ingress_error
                .to_string()
                .contains("cannot be combined with injected egress or ingress")
        );
    }

    #[rstest]
    #[tokio::test(flavor = "current_thread")]
    async fn test_run_republishes_external_ingress_on_local_msgbus() {
        let quote = QuoteTick::default();
        let received = Rc::new(RefCell::new(Vec::<QuoteTick>::new()));
        let payload =
            Bytes::from(serde_json::to_vec(&quote).expect("QuoteTick should serialize as JSON"));
        let message = BusMessage::with_str_topic(
            "data.quotes.TEST",
            BusPayloadType::QuoteTick,
            payload,
            SerializationEncoding::Json,
        );
        let (tx, rx) = tokio::sync::mpsc::channel::<BusMessage>(1);
        let closed = Rc::new(Cell::new(false));
        let ingress = CapturingExternalIngress::new(rx, closed.clone());
        let config = LiveNodeConfig {
            environment: Environment::Sandbox,
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            delay_post_stop: Duration::ZERO,
            timeout_connection: Duration::from_millis(500),
            timeout_disconnection: Duration::from_millis(500),
            ..Default::default()
        };
        let mut node = LiveNodeBuilder::from_config(config)
            .unwrap()
            .with_external_ingress(Box::new(ingress))
            .build()
            .expect("node builds with external message bus ingress");
        let handle = node.handle();
        let handler = TypedHandler::from({
            let received = received.clone();
            move |quote: &QuoteTick| {
                received.borrow_mut().push(*quote);
            }
        });
        msgbus::subscribe_quotes("data.quotes.*".into(), handler, None);
        msgbus::get_message_bus()
            .borrow_mut()
            .add_streaming_type(BusPayloadType::QuoteTick);

        tokio::time::timeout(Duration::from_secs(30), async {
            let run = node.run();
            tokio::pin!(run);

            let drive = async {
                wait_until_async(|| async { handle.is_running() }, Duration::from_secs(10)).await;

                tx.send(message)
                    .await
                    .expect("external ingress receiver should be open");

                wait_until_async(
                    || async { received.borrow().len() == 1 },
                    Duration::from_secs(10),
                )
                .await;
                assert_eq!(*received.borrow(), vec![quote]);
                handle.stop();
            };

            tokio::select! {
                biased;

                () = drive => {}
                result = &mut run => {
                    panic!("node stopped before external message was republished: {result:?}");
                }
            }

            run.await.expect("node should stop cleanly");
        })
        .await
        .expect("live node should republish ingress and stop before timeout");

        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(closed.get());
        msgbus::get_message_bus().borrow_mut().dispose();
    }

    #[rstest]
    #[tokio::test(flavor = "current_thread")]
    async fn test_run_closes_external_ingress_when_receiver_closes() {
        let (tx, rx) = tokio::sync::mpsc::channel::<BusMessage>(1);
        let closed = Rc::new(Cell::new(false));
        let ingress = CapturingExternalIngress::new(rx, closed.clone());
        let config = LiveNodeConfig {
            environment: Environment::Sandbox,
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            delay_post_stop: Duration::ZERO,
            timeout_connection: Duration::from_millis(500),
            timeout_disconnection: Duration::from_millis(500),
            ..Default::default()
        };
        let mut node = LiveNodeBuilder::from_config(config)
            .unwrap()
            .with_external_ingress(Box::new(ingress))
            .build()
            .expect("node builds with external message bus ingress");
        let handle = node.handle();

        tokio::time::timeout(Duration::from_secs(30), async {
            let run = node.run();
            tokio::pin!(run);

            let drive = async {
                wait_until_async(|| async { handle.is_running() }, Duration::from_secs(10)).await;

                drop(tx);

                wait_until_async(|| async { closed.get() }, Duration::from_secs(10)).await;
                assert!(
                    handle.is_running(),
                    "node should keep running after ingress closes"
                );
                handle.stop();
            };

            tokio::select! {
                biased;

                () = drive => {}
                result = &mut run => {
                    panic!("node stopped before ingress close was observed: {result:?}");
                }
            }

            run.await.expect("node should stop cleanly");
        })
        .await
        .expect("live node should close ingress and stop before timeout");

        assert_eq!(handle.state(), NodeState::Stopped);
    }

    #[rstest]
    #[tokio::test(flavor = "current_thread")]
    async fn test_run_aborts_startup_when_external_ingress_receiver_unavailable() {
        let closed = Rc::new(Cell::new(false));
        let ingress = FailingExternalIngress::new(closed.clone());
        let config = LiveNodeConfig {
            environment: Environment::Sandbox,
            exec_engine: crate::config::LiveExecEngineConfig {
                reconciliation: false,
                ..Default::default()
            },
            delay_post_stop: Duration::ZERO,
            timeout_connection: Duration::from_millis(500),
            timeout_disconnection: Duration::from_millis(500),
            ..Default::default()
        };
        let mut node = LiveNodeBuilder::from_config(config)
            .unwrap()
            .with_external_ingress(Box::new(ingress))
            .build()
            .expect("node builds with external message bus ingress");
        let handle = node.handle();

        let err = node.run().await.expect_err("run should fail");

        assert!(
            err.to_string()
                .contains("external ingress receiver unavailable")
        );
        assert_eq!(handle.state(), NodeState::Stopped);
        assert!(closed.get());
    }

    #[cfg(feature = "python")]
    #[rstest]
    fn test_node_build_and_initial_state() {
        let node = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox)
            .unwrap()
            .with_name("TestNode")
            .build()
            .unwrap();

        assert_eq!(node.state(), NodeState::Idle);
        assert!(!node.is_running());
        assert_eq!(node.environment(), Environment::Sandbox);
        assert_eq!(node.trader_id(), TraderId::from("TRADER-001"));
    }

    #[cfg(feature = "python")]
    #[rstest]
    fn test_node_build_replaces_stale_runner_senders() {
        replace_data_cmd_sender(Arc::new(SyncDataCommandSender));
        replace_exec_cmd_sender(Arc::new(SyncTradingCommandSender));

        let first = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox)
            .unwrap()
            .with_name("FirstNode")
            .build()
            .unwrap();

        assert_eq!(first.state(), NodeState::Idle);
        drop(first);

        let second = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox)
            .unwrap()
            .with_name("SecondNode")
            .build()
            .unwrap();

        assert_eq!(second.state(), NodeState::Idle);
        assert!(!second.is_running());
    }

    #[cfg(feature = "python")]
    #[rstest]
    fn test_node_handle_reflects_node_state() {
        let node = LiveNode::builder(TraderId::from("TRADER-001"), Environment::Sandbox)
            .unwrap()
            .with_name("TestNode")
            .build()
            .unwrap();

        let handle = node.handle();

        assert_eq!(handle.state(), NodeState::Idle);
        assert!(!handle.is_running());
    }

    #[rstest]
    fn test_pending_drain_data_returns_false_when_empty() {
        let mut pending = PendingEvents::default();

        assert!(!pending.drain_data());
    }

    #[rstest]
    fn test_pending_drain_data_returns_true_when_non_empty() {
        use nautilus_model::instruments::{InstrumentAny, stubs::crypto_perpetual_ethusdt};

        let mut pending = PendingEvents::default();
        pending
            .data_evts
            .push(DataEvent::Instrument(InstrumentAny::CryptoPerpetual(
                crypto_perpetual_ethusdt(),
            )));

        assert!(pending.drain_data());
        assert!(pending.data_evts.is_empty());
    }

    fn stub_data_event() -> DataEvent {
        use nautilus_model::instruments::{InstrumentAny, stubs::crypto_perpetual_ethusdt};

        DataEvent::Instrument(InstrumentAny::CryptoPerpetual(crypto_perpetual_ethusdt()))
    }

    fn stub_data_command() -> DataCommand {
        use nautilus_common::messages::data::{SubscribeCommand, subscribe::SubscribeInstruments};
        use nautilus_core::{UUID4, UnixNanos};
        use nautilus_model::identifiers::Venue;

        DataCommand::Subscribe(SubscribeCommand::Instruments(SubscribeInstruments::new(
            None,
            Venue::from("TEST"),
            UUID4::new(),
            UnixNanos::default(),
            None,
            None,
        )))
    }

    fn stub_system_command() -> SystemCommand {
        SystemCommand::ReconnectSocket(ReconnectSocket::new(
            TraderId::from("TRADER-001"),
            ClientId::from("POLYMARKET"),
            Ustr::from("polymarket-market-streams"),
            UnixNanos::default(),
        ))
    }

    #[rstest]
    fn test_flush_pending_data_drains_events_and_commands() {
        let (evt_tx, mut evt_rx) = tokio::sync::mpsc::unbounded_channel::<DataEvent>();
        let (cmd_tx, mut cmd_rx) = tokio::sync::mpsc::unbounded_channel::<DataCommand>();

        let mut pending = PendingEvents::default();

        // Pre-load pending (items captured by the select loop)
        pending.data_evts.push(stub_data_event());
        pending.data_cmds.push(stub_data_command());

        // Pre-load channels (items missed by the select loop)
        evt_tx.send(stub_data_event()).unwrap();
        cmd_tx.send(stub_data_command()).unwrap();

        flush_pending_data(&mut pending, &mut evt_rx, &mut cmd_rx);

        assert!(pending.data_evts.is_empty());
        assert!(pending.data_cmds.is_empty());
        assert!(evt_rx.try_recv().is_err());
        assert!(cmd_rx.try_recv().is_err());
    }

    #[rstest]
    fn test_flush_pending_data_drains_mixed_sources() {
        let (evt_tx, mut evt_rx) = tokio::sync::mpsc::unbounded_channel::<DataEvent>();
        let (cmd_tx, mut cmd_rx) = tokio::sync::mpsc::unbounded_channel::<DataCommand>();

        let mut pending = PendingEvents::default();

        // First pass: pending has an event, channel has a command
        pending.data_evts.push(stub_data_event());
        cmd_tx.send(stub_data_command()).unwrap();

        // Second pass: channel has items that simulate arrival during first drain
        evt_tx.send(stub_data_event()).unwrap();
        evt_tx.send(stub_data_event()).unwrap();
        cmd_tx.send(stub_data_command()).unwrap();

        flush_pending_data(&mut pending, &mut evt_rx, &mut cmd_rx);

        assert!(pending.data_evts.is_empty());
        assert!(pending.data_cmds.is_empty());
        assert!(evt_rx.try_recv().is_err());
        assert!(cmd_rx.try_recv().is_err());
    }

    #[rstest]
    fn test_pending_system_events_stay_separate_from_data() {
        let mut pending = PendingEvents::default();
        let change = SocketStateChange::new(
            ClientId::from("BINANCE"),
            Some(Venue::from("BINANCE")),
            ustr::Ustr::from("binance-futures-market-streams"),
            SocketState::Connected,
        );

        pending.system_events.push(SystemEvent::SocketState(change));
        let system_events = pending.take_system_events();

        assert_eq!(system_events, vec![SystemEvent::SocketState(change)]);
        assert!(pending.is_empty());
    }

    #[rstest]
    fn test_pending_system_commands_stay_separate_from_data() {
        let mut pending = PendingEvents::default();
        let command = stub_system_command();

        pending.system_commands.push(command);
        let system_commands = pending.take_system_commands();

        assert_eq!(system_commands, vec![command]);
        assert!(pending.is_empty());
    }

    fn stub_time_event_handler() -> TimeEventMessage {
        use std::rc::Rc;

        use nautilus_common::{
            runner::TimeEventMessage,
            timer::{TimeEvent, TimeEventCallback},
        };
        use nautilus_core::{UUID4, UnixNanos};
        use ustr::Ustr;

        TimeEventMessage::new(
            TimeEvent::new(
                Ustr::from("test-timer"),
                UUID4::new(),
                UnixNanos::default(),
                UnixNanos::default(),
            ),
            TimeEventCallback::RustLocal(Rc::new(|_| {})),
        )
    }

    fn stub_trading_command_message() -> TradingCommandMessage {
        use nautilus_common::messages::execution::query::QueryAccount;
        use nautilus_core::{UUID4, UnixNanos};
        use nautilus_model::identifiers::AccountId;

        TradingCommandMessage::new(
            MessagingSwitchboard::exec_engine_execute(),
            TradingCommand::QueryAccount(QueryAccount::new(
                TraderId::from("TESTER-001"),
                None,
                AccountId::from("TEST-001"),
                UUID4::new(),
                UnixNanos::default(),
                None,
                None, // correlation_id
            )),
        )
    }

    fn stub_exec_event() -> ExecutionEvent {
        use nautilus_model::{
            enums::{LiquiditySide, OrderSide},
            identifiers::{AccountId, InstrumentId, TradeId, VenueOrderId},
            reports::FillReport,
            types::{Money, Price, Quantity},
        };

        ExecutionEvent::Report(ExecutionReport::Fill(Box::new(FillReport::new(
            AccountId::from("TEST-001"),
            InstrumentId::from("TEST.VENUE"),
            VenueOrderId::from("V-001"),
            TradeId::from("T-001"),
            OrderSide::Buy,
            Quantity::from("1.0"),
            Price::from("100.0"),
            Money::from("0.01 USD"),
            LiquiditySide::Maker,
            None,
            None,
            nautilus_core::UnixNanos::default(),
            nautilus_core::UnixNanos::default(),
            None,
        ))))
    }

    #[rstest]
    fn test_flush_all_pending_drains_buffered_channels() {
        let (time_tx, mut time_rx) = tokio::sync::mpsc::unbounded_channel::<TimeEventMessage>();
        let (system_evt_tx, mut system_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemEvent>();
        let (system_cmd_tx, mut system_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemCommand>();
        let (data_evt_tx, mut data_evt_rx) = tokio::sync::mpsc::unbounded_channel::<DataEvent>();
        let (data_cmd_tx, mut data_cmd_rx) = tokio::sync::mpsc::unbounded_channel::<DataCommand>();
        let (exec_evt_tx, mut exec_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<ExecutionEvent>();
        let (exec_cmd_tx, mut exec_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<TradingCommandMessage>();

        let mut pending = PendingEvents::default();

        // Pre-load pending with data items
        pending.data_evts.push(stub_data_event());
        pending.data_cmds.push(stub_data_command());

        // Pre-load all channel types
        time_tx.send(stub_time_event_handler()).unwrap();
        let change = SocketStateChange::new(
            ClientId::from("BINANCE"),
            Some(Venue::from("BINANCE")),
            Ustr::from("binance-futures-market-streams"),
            SocketState::Connected,
        );
        system_evt_tx
            .send(SystemEvent::SocketState(change))
            .unwrap();
        system_cmd_tx.send(stub_system_command()).unwrap();
        data_evt_tx.send(stub_data_event()).unwrap();
        data_cmd_tx.send(stub_data_command()).unwrap();
        exec_evt_tx.send(stub_exec_event()).unwrap();
        exec_cmd_tx.send(stub_trading_command_message()).unwrap();

        flush_all_pending(
            &mut pending,
            &mut time_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        );

        let system_events = pending.take_system_events();
        let system_commands = pending.take_system_commands();
        assert_eq!(system_events, vec![SystemEvent::SocketState(change)]);
        assert_eq!(system_commands, vec![stub_system_command()]);
        assert!(pending.data_evts.is_empty());
        assert!(pending.data_cmds.is_empty());
        assert!(pending.exec_reports.is_empty());
        assert!(pending.exec_cmds.is_empty());
        assert!(pending.order_evts.is_empty());
        assert!(time_rx.try_recv().is_err());
        assert!(system_evt_rx.try_recv().is_err());
        assert!(system_cmd_rx.try_recv().is_err());
        assert!(data_evt_rx.try_recv().is_err());
        assert!(data_cmd_rx.try_recv().is_err());
        assert!(exec_evt_rx.try_recv().is_err());
        assert!(exec_cmd_rx.try_recv().is_err());
    }

    fn stub_order_event() -> ExecutionEvent {
        use nautilus_model::events::order::spec::OrderSubmittedSpec;

        ExecutionEvent::Order(OrderEventAny::Submitted(
            OrderSubmittedSpec::builder().build(),
        ))
    }

    fn stub_account_event() -> ExecutionEvent {
        use nautilus_core::{UUID4, UnixNanos};
        use nautilus_model::{
            enums::AccountType, events::account::state::AccountState, identifiers::AccountId,
        };

        ExecutionEvent::Account(AccountState::new(
            AccountId::from("TEST-001"),
            AccountType::Cash,
            vec![],
            vec![],
            true,
            UUID4::new(),
            UnixNanos::default(),
            UnixNanos::default(),
            None,
        ))
    }

    #[rstest]
    fn test_flush_all_pending_routes_order_event_to_order_evts() {
        let (_time_tx, mut time_rx) = tokio::sync::mpsc::unbounded_channel::<TimeEventMessage>();
        let (_system_evt_tx, mut system_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemEvent>();
        let (_system_cmd_tx, mut system_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemCommand>();
        let (_data_evt_tx, mut data_evt_rx) = tokio::sync::mpsc::unbounded_channel::<DataEvent>();
        let (_data_cmd_tx, mut data_cmd_rx) = tokio::sync::mpsc::unbounded_channel::<DataCommand>();
        let (exec_evt_tx, mut exec_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<ExecutionEvent>();
        let (_exec_cmd_tx, mut exec_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<TradingCommandMessage>();

        let mut pending = PendingEvents::default();

        exec_evt_tx.send(stub_order_event()).unwrap();
        exec_evt_tx.send(stub_exec_event()).unwrap();

        flush_all_pending(
            &mut pending,
            &mut time_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        );

        // Both order and report events are drained by pending.drain()
        assert!(pending.order_evts.is_empty());
        assert!(pending.exec_reports.is_empty());
        assert!(exec_evt_rx.try_recv().is_err());
    }

    #[rstest]
    fn test_flush_all_pending_routes_account_event_immediately() {
        let (_time_tx, mut time_rx) = tokio::sync::mpsc::unbounded_channel::<TimeEventMessage>();
        let (_system_evt_tx, mut system_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemEvent>();
        let (_system_cmd_tx, mut system_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemCommand>();
        let (_data_evt_tx, mut data_evt_rx) = tokio::sync::mpsc::unbounded_channel::<DataEvent>();
        let (_data_cmd_tx, mut data_cmd_rx) = tokio::sync::mpsc::unbounded_channel::<DataCommand>();
        let (exec_evt_tx, mut exec_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<ExecutionEvent>();
        let (_exec_cmd_tx, mut exec_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<TradingCommandMessage>();

        let mut pending = PendingEvents::default();

        exec_evt_tx.send(stub_account_event()).unwrap();

        flush_all_pending(
            &mut pending,
            &mut time_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        );

        // Account events are forwarded immediately, never buffered in pending
        assert!(pending.exec_reports.is_empty());
        assert!(pending.order_evts.is_empty());
        assert!(pending.exec_cmds.is_empty());
        assert!(exec_evt_rx.try_recv().is_err());
    }

    #[rstest]
    fn test_pending_is_empty_when_default() {
        let pending = PendingEvents::default();

        assert!(pending.is_empty());
    }

    #[rstest]
    fn test_pending_is_empty_false_with_data_evt() {
        let mut pending = PendingEvents::default();
        pending.data_evts.push(stub_data_event());

        assert!(!pending.is_empty());
    }

    #[rstest]
    fn test_pending_is_empty_false_with_data_cmd() {
        let mut pending = PendingEvents::default();
        pending.data_cmds.push(stub_data_command());

        assert!(!pending.is_empty());
    }

    #[rstest]
    fn test_pending_is_empty_false_with_exec_cmd() {
        let mut pending = PendingEvents::default();
        pending.exec_cmds.push(stub_trading_command_message());

        assert!(!pending.is_empty());
    }

    #[rstest]
    fn test_pending_drain_preserves_trading_command_target() {
        std::thread::spawn(|| {
            msgbus::get_message_bus().borrow_mut().dispose();
            let risk_commands = Rc::new(RefCell::new(Vec::new()));
            let exec_commands = Rc::new(RefCell::new(Vec::new()));

            let risk_commands_handler = risk_commands.clone();
            msgbus::register_trading_command_endpoint(
                MessagingSwitchboard::risk_engine_execute(),
                TypedIntoHandler::from(move |command: TradingCommand| {
                    risk_commands_handler.borrow_mut().push(command);
                }),
            );
            let exec_commands_handler = exec_commands.clone();
            msgbus::register_trading_command_endpoint(
                MessagingSwitchboard::exec_engine_execute(),
                TypedIntoHandler::from(move |command: TradingCommand| {
                    exec_commands_handler.borrow_mut().push(command);
                }),
            );

            let mut pending = PendingEvents::default();
            pending.exec_cmds.push(TradingCommandMessage::new(
                MessagingSwitchboard::risk_engine_execute(),
                TradingCommand::QueryAccount(QueryAccount::new(
                    TraderId::from("TESTER-001"),
                    None,
                    AccountId::from("TEST-001"),
                    UUID4::new(),
                    UnixNanos::default(),
                    None,
                    None,
                )),
            ));

            pending.drain();

            assert!(pending.is_empty());
            assert_eq!(risk_commands.borrow().len(), 1);
            assert!(matches!(
                &risk_commands.borrow()[0],
                TradingCommand::QueryAccount(_)
            ));
            assert_eq!(exec_commands.borrow().as_slice(), &[]);
        })
        .join()
        .unwrap();
    }

    #[rstest]
    fn test_pending_is_empty_false_with_exec_report() {
        let mut pending = PendingEvents::default();

        if let ExecutionEvent::Report(report) = stub_exec_event() {
            pending.exec_reports.push(report);
        }

        assert!(!pending.is_empty());
    }

    #[rstest]
    fn test_pending_is_empty_false_with_order_evt() {
        let mut pending = PendingEvents::default();

        if let ExecutionEvent::Order(order_evt) = stub_order_event() {
            pending.order_evts.push(order_evt);
        }

        assert!(!pending.is_empty());
    }

    fn stub_submitted_batch_event() -> ExecutionEvent {
        use nautilus_model::{
            events::{OrderSubmittedBatch, order::spec::OrderSubmittedSpec},
            identifiers::ClientOrderId,
        };

        let events = vec![
            OrderSubmittedSpec::builder()
                .client_order_id(ClientOrderId::from("O-001"))
                .build(),
            OrderSubmittedSpec::builder()
                .client_order_id(ClientOrderId::from("O-002"))
                .build(),
        ];

        ExecutionEvent::OrderSubmittedBatch(OrderSubmittedBatch::new(events))
    }

    fn stub_canceled_batch_event() -> ExecutionEvent {
        use nautilus_model::{
            events::{OrderCanceledBatch, order::spec::OrderCanceledSpec},
            identifiers::ClientOrderId,
        };

        let events = vec![
            OrderCanceledSpec::builder()
                .client_order_id(ClientOrderId::from("O-001"))
                .build(),
            OrderCanceledSpec::builder()
                .client_order_id(ClientOrderId::from("O-002"))
                .build(),
        ];

        ExecutionEvent::OrderCanceledBatch(OrderCanceledBatch::new(events))
    }

    #[rstest]
    fn test_flush_all_pending_buffers_submitted_batch_as_individual_events() {
        let (_time_tx, mut time_rx) = tokio::sync::mpsc::unbounded_channel::<TimeEventMessage>();
        let (_system_evt_tx, mut system_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemEvent>();
        let (_system_cmd_tx, mut system_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemCommand>();
        let (_data_evt_tx, mut data_evt_rx) = tokio::sync::mpsc::unbounded_channel::<DataEvent>();
        let (_data_cmd_tx, mut data_cmd_rx) = tokio::sync::mpsc::unbounded_channel::<DataCommand>();
        let (exec_evt_tx, mut exec_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<ExecutionEvent>();
        let (_exec_cmd_tx, mut exec_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<TradingCommandMessage>();

        let mut pending = PendingEvents::default();

        exec_evt_tx.send(stub_submitted_batch_event()).unwrap();

        flush_all_pending(
            &mut pending,
            &mut time_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        );

        // Batch should be unpacked into individual Submitted events then drained
        assert!(pending.order_evts.is_empty());
        assert!(exec_evt_rx.try_recv().is_err());
    }

    #[rstest]
    fn test_flush_all_pending_buffers_canceled_batch_as_individual_events() {
        let (_time_tx, mut time_rx) = tokio::sync::mpsc::unbounded_channel::<TimeEventMessage>();
        let (_system_evt_tx, mut system_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemEvent>();
        let (_system_cmd_tx, mut system_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<SystemCommand>();
        let (_data_evt_tx, mut data_evt_rx) = tokio::sync::mpsc::unbounded_channel::<DataEvent>();
        let (_data_cmd_tx, mut data_cmd_rx) = tokio::sync::mpsc::unbounded_channel::<DataCommand>();
        let (exec_evt_tx, mut exec_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<ExecutionEvent>();
        let (_exec_cmd_tx, mut exec_cmd_rx) =
            tokio::sync::mpsc::unbounded_channel::<TradingCommandMessage>();

        let mut pending = PendingEvents::default();

        exec_evt_tx.send(stub_canceled_batch_event()).unwrap();

        flush_all_pending(
            &mut pending,
            &mut time_rx,
            &mut system_evt_rx,
            &mut system_cmd_rx,
            &mut exec_evt_rx,
            &mut exec_cmd_rx,
            &mut data_evt_rx,
            &mut data_cmd_rx,
        );

        // Batch should be unpacked into individual Canceled events then drained
        assert!(pending.order_evts.is_empty());
        assert!(exec_evt_rx.try_recv().is_err());
    }

    #[rstest]
    fn test_flush_all_pending_expands_batch_into_order_evts_before_drain() {
        use nautilus_model::identifiers::ClientOrderId;

        let (exec_evt_tx, mut exec_evt_rx) =
            tokio::sync::mpsc::unbounded_channel::<ExecutionEvent>();

        exec_evt_tx.send(stub_canceled_batch_event()).unwrap();

        let mut pending = PendingEvents::default();

        // Manually replicate what flush_all_pending does before drain
        while let Ok(evt) = exec_evt_rx.try_recv() {
            match evt {
                ExecutionEvent::Account(_) => {
                    AsyncRunner::handle_exec_event(evt);
                }
                ExecutionEvent::Report(report) => {
                    pending.exec_reports.push(report);
                }
                ExecutionEvent::Order(order_evt) => {
                    pending.order_evts.push(order_evt);
                }
                ExecutionEvent::OrderSubmittedBatch(batch) => {
                    for submitted in batch {
                        pending.order_evts.push(OrderEventAny::Submitted(submitted));
                    }
                }
                ExecutionEvent::OrderAcceptedBatch(batch) => {
                    for accepted in batch {
                        pending.order_evts.push(OrderEventAny::Accepted(accepted));
                    }
                }
                ExecutionEvent::OrderCanceledBatch(batch) => {
                    for canceled in batch {
                        pending.order_evts.push(OrderEventAny::Canceled(canceled));
                    }
                }
            }
        }

        assert_eq!(pending.order_evts.len(), 2);
        assert!(
            matches!(&pending.order_evts[0], OrderEventAny::Canceled(c) if c.client_order_id == ClientOrderId::from("O-001"))
        );
        assert!(
            matches!(&pending.order_evts[1], OrderEventAny::Canceled(c) if c.client_order_id == ClientOrderId::from("O-002"))
        );
    }

    #[derive(Debug)]
    struct CapturedEgressMessage {
        topic: String,
        payload: Bytes,
    }

    type CapturedEgressMessages = Rc<RefCell<Vec<CapturedEgressMessage>>>;
    type SharedClosed = Rc<Cell<bool>>;

    #[derive(Debug)]
    struct CapturingExternalIngress {
        rx: Option<tokio::sync::mpsc::Receiver<BusMessage>>,
        closed: SharedClosed,
    }

    impl CapturingExternalIngress {
        fn new(rx: tokio::sync::mpsc::Receiver<BusMessage>, closed: SharedClosed) -> Self {
            Self {
                rx: Some(rx),
                closed,
            }
        }
    }

    impl MessageBusExternalIngress for CapturingExternalIngress {
        fn is_closed(&self) -> bool {
            self.closed.get()
        }

        fn take_receiver(&mut self) -> anyhow::Result<tokio::sync::mpsc::Receiver<BusMessage>> {
            self.rx
                .take()
                .ok_or_else(|| anyhow::anyhow!("external ingress receiver already taken"))
        }

        fn close(&mut self) {
            self.closed.set(true);
        }
    }

    #[derive(Debug)]
    struct FailingExternalIngress {
        closed: SharedClosed,
    }

    impl FailingExternalIngress {
        fn new(closed: SharedClosed) -> Self {
            Self { closed }
        }
    }

    impl MessageBusExternalIngress for FailingExternalIngress {
        fn is_closed(&self) -> bool {
            self.closed.get()
        }

        fn take_receiver(&mut self) -> anyhow::Result<tokio::sync::mpsc::Receiver<BusMessage>> {
            anyhow::bail!("external ingress receiver unavailable")
        }

        fn close(&mut self) {
            self.closed.set(true);
        }
    }

    struct CapturingExternalEgress {
        publications: CapturedEgressMessages,
        closed: SharedClosed,
    }

    impl CapturingExternalEgress {
        fn new() -> (Self, CapturedEgressMessages, SharedClosed) {
            let publications = Rc::new(RefCell::new(Vec::new()));
            let closed = Rc::new(Cell::new(false));
            (
                Self {
                    publications: publications.clone(),
                    closed: closed.clone(),
                },
                publications,
                closed,
            )
        }
    }

    impl MessageBusExternalEgress for CapturingExternalEgress {
        fn is_closed(&self) -> bool {
            self.closed.get()
        }

        fn publish(&self, message: BusMessage) {
            self.publications.borrow_mut().push(CapturedEgressMessage {
                topic: message.topic.to_string(),
                payload: message.payload,
            });
        }

        fn close(&mut self) {
            self.closed.set(true);
        }
    }

    struct CapturingBackingFactory {
        publications: Arc<Mutex<Vec<CapturedEgressMessage>>>,
        closed: Arc<AtomicBool>,
        rx: Mutex<Option<tokio::sync::mpsc::Receiver<BusMessage>>>,
    }

    impl CapturingBackingFactory {
        fn new(
            publications: Arc<Mutex<Vec<CapturedEgressMessage>>>,
            closed: Arc<AtomicBool>,
            rx: Option<tokio::sync::mpsc::Receiver<BusMessage>>,
        ) -> Self {
            Self {
                publications,
                closed,
                rx: Mutex::new(rx),
            }
        }
    }

    impl Debug for CapturingBackingFactory {
        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
            f.debug_struct(stringify!(CapturingBackingFactory))
                .finish_non_exhaustive()
        }
    }

    impl MessageBusBackingFactory for CapturingBackingFactory {
        fn create(
            &self,
            _trader_id: TraderId,
            _instance_id: UUID4,
            _config: MessageBusConfig,
        ) -> anyhow::Result<Box<dyn MessageBusBacking>> {
            let rx = self.rx.lock().unwrap().take();
            Ok(Box::new(CapturingBacking {
                publications: self.publications.clone(),
                closed: self.closed.clone(),
                rx,
            }))
        }
    }

    struct CapturingBacking {
        publications: Arc<Mutex<Vec<CapturedEgressMessage>>>,
        closed: Arc<AtomicBool>,
        rx: Option<tokio::sync::mpsc::Receiver<BusMessage>>,
    }

    impl MessageBusBacking for CapturingBacking {
        fn is_closed(&self) -> bool {
            self.closed.load(Ordering::Relaxed)
        }

        fn publish(&self, message: BusMessage) {
            self.publications
                .lock()
                .unwrap()
                .push(CapturedEgressMessage {
                    topic: message.topic.to_string(),
                    payload: message.payload,
                });
        }

        fn take_receiver(&mut self) -> anyhow::Result<tokio::sync::mpsc::Receiver<BusMessage>> {
            self.rx
                .take()
                .ok_or_else(|| anyhow::anyhow!("external ingress receiver unavailable"))
        }

        fn close(&mut self) {
            self.closed.store(true, Ordering::Relaxed);
        }
    }
}