nautilus_common/cache/

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.
// -------------------------------------------------------------------------------------------------

//! In-memory cache for market and execution data, with optional persistent backing.
//!
//! Provides methods to load, query, and update cached data such as instruments, orders, and prices.

pub mod config;
pub mod database;
pub mod fifo;
pub mod quote;

mod index;

#[cfg(test)]
mod tests;

use std::{
    collections::VecDeque,
    fmt::{Debug, Display},
    time::{SystemTime, UNIX_EPOCH},
};

use ahash::{AHashMap, AHashSet};
use bytes::Bytes;
pub use config::CacheConfig; // Re-export
use database::{CacheDatabaseAdapter, CacheMap};
use index::CacheIndex;
use nautilus_core::{
    UUID4, UnixNanos,
    correctness::{
        check_key_not_in_map, check_predicate_false, check_slice_not_empty,
        check_valid_string_ascii,
    },
    datetime::secs_to_nanos_unchecked,
};
use nautilus_model::{
    accounts::{Account, AccountAny},
    data::{
        Bar, BarType, FundingRateUpdate, GreeksData, IndexPriceUpdate, MarkPriceUpdate, QuoteTick,
        TradeTick, YieldCurveData,
    },
    enums::{AggregationSource, OmsType, OrderSide, PositionSide, PriceType, TriggerType},
    identifiers::{
        AccountId, ClientId, ClientOrderId, ComponentId, ExecAlgorithmId, InstrumentId,
        OrderListId, PositionId, StrategyId, Venue, VenueOrderId,
    },
    instruments::{Instrument, InstrumentAny, SyntheticInstrument},
    orderbook::{
        OrderBook,
        own::{OwnOrderBook, should_handle_own_book_order},
    },
    orders::{Order, OrderAny, OrderList},
    position::Position,
    types::{Currency, Money, Price, Quantity},
};
use ustr::Ustr;

use crate::xrate::get_exchange_rate;

/// A common in-memory `Cache` for market and execution related data.
#[cfg_attr(
    feature = "python",
    pyo3::pyclass(module = "nautilus_trader.core.nautilus_pyo3.common", unsendable)
)]
pub struct Cache {
    config: CacheConfig,
    index: CacheIndex,
    database: Option<Box<dyn CacheDatabaseAdapter>>,
    general: AHashMap<String, Bytes>,
    currencies: AHashMap<Ustr, Currency>,
    instruments: AHashMap<InstrumentId, InstrumentAny>,
    synthetics: AHashMap<InstrumentId, SyntheticInstrument>,
    books: AHashMap<InstrumentId, OrderBook>,
    own_books: AHashMap<InstrumentId, OwnOrderBook>,
    quotes: AHashMap<InstrumentId, VecDeque<QuoteTick>>,
    trades: AHashMap<InstrumentId, VecDeque<TradeTick>>,
    mark_xrates: AHashMap<(Currency, Currency), f64>,
    mark_prices: AHashMap<InstrumentId, VecDeque<MarkPriceUpdate>>,
    index_prices: AHashMap<InstrumentId, VecDeque<IndexPriceUpdate>>,
    funding_rates: AHashMap<InstrumentId, VecDeque<FundingRateUpdate>>,
    bars: AHashMap<BarType, VecDeque<Bar>>,
    greeks: AHashMap<InstrumentId, GreeksData>,
    yield_curves: AHashMap<String, YieldCurveData>,
    accounts: AHashMap<AccountId, AccountAny>,
    orders: AHashMap<ClientOrderId, OrderAny>,
    order_lists: AHashMap<OrderListId, OrderList>,
    positions: AHashMap<PositionId, Position>,
    position_snapshots: AHashMap<PositionId, Bytes>,
    #[cfg(feature = "defi")]
    pub(crate) defi: crate::defi::cache::DefiCache,
}

impl Debug for Cache {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct(stringify!(Cache))
            .field("config", &self.config)
            .field("index", &self.index)
            .field("general", &self.general)
            .field("currencies", &self.currencies)
            .field("instruments", &self.instruments)
            .field("synthetics", &self.synthetics)
            .field("books", &self.books)
            .field("own_books", &self.own_books)
            .field("quotes", &self.quotes)
            .field("trades", &self.trades)
            .field("mark_xrates", &self.mark_xrates)
            .field("mark_prices", &self.mark_prices)
            .field("index_prices", &self.index_prices)
            .field("funding_rates", &self.funding_rates)
            .field("bars", &self.bars)
            .field("greeks", &self.greeks)
            .field("yield_curves", &self.yield_curves)
            .field("accounts", &self.accounts)
            .field("orders", &self.orders)
            .field("order_lists", &self.order_lists)
            .field("positions", &self.positions)
            .field("position_snapshots", &self.position_snapshots)
            .finish()
    }
}

impl Default for Cache {
    /// Creates a new default [`Cache`] instance.
    fn default() -> Self {
        Self::new(Some(CacheConfig::default()), None)
    }
}

impl Cache {
    /// Creates a new [`Cache`] instance with optional configuration and database adapter.
    #[must_use]
    /// # Note
    ///
    /// Uses provided `CacheConfig` or defaults, and optional `CacheDatabaseAdapter` for persistence.
    pub fn new(
        config: Option<CacheConfig>,
        database: Option<Box<dyn CacheDatabaseAdapter>>,
    ) -> Self {
        Self {
            config: config.unwrap_or_default(),
            index: CacheIndex::default(),
            database,
            general: AHashMap::new(),
            currencies: AHashMap::new(),
            instruments: AHashMap::new(),
            synthetics: AHashMap::new(),
            books: AHashMap::new(),
            own_books: AHashMap::new(),
            quotes: AHashMap::new(),
            trades: AHashMap::new(),
            mark_xrates: AHashMap::new(),
            mark_prices: AHashMap::new(),
            index_prices: AHashMap::new(),
            funding_rates: AHashMap::new(),
            bars: AHashMap::new(),
            greeks: AHashMap::new(),
            yield_curves: AHashMap::new(),
            accounts: AHashMap::new(),
            orders: AHashMap::new(),
            order_lists: AHashMap::new(),
            positions: AHashMap::new(),
            position_snapshots: AHashMap::new(),
            #[cfg(feature = "defi")]
            defi: crate::defi::cache::DefiCache::default(),
        }
    }

    /// Returns the cache instances memory address.
    #[must_use]
    pub fn memory_address(&self) -> String {
        format!("{:?}", std::ptr::from_ref(self))
    }

    /// Sets the cache database adapter for persistence.
    ///
    /// This allows setting or replacing the database adapter after cache construction.
    pub fn set_database(&mut self, database: Box<dyn CacheDatabaseAdapter>) {
        let type_name = std::any::type_name_of_val(&*database);
        log::info!("Cache database adapter set: {type_name}");
        self.database = Some(database);
    }

    // -- COMMANDS --------------------------------------------------------------------------------

    /// Clears and reloads general entries from the database into the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if loading general cache data fails.
    pub fn cache_general(&mut self) -> anyhow::Result<()> {
        self.general = match &mut self.database {
            Some(db) => db.load()?,
            None => AHashMap::new(),
        };

        log::info!(
            "Cached {} general object(s) from database",
            self.general.len()
        );
        Ok(())
    }

    /// Loads all core caches (currencies, instruments, accounts, orders, positions) from the database.
    ///
    /// # Errors
    ///
    /// Returns an error if loading all cache data fails.
    pub async fn cache_all(&mut self) -> anyhow::Result<()> {
        let cache_map = match &self.database {
            Some(db) => db.load_all().await?,
            None => CacheMap::default(),
        };

        self.currencies = cache_map.currencies;
        self.instruments = cache_map.instruments;
        self.synthetics = cache_map.synthetics;
        self.accounts = cache_map.accounts;
        self.orders = cache_map.orders;
        self.positions = cache_map.positions;
        Ok(())
    }

    /// Clears and reloads the currency cache from the database.
    ///
    /// # Errors
    ///
    /// Returns an error if loading currencies cache fails.
    pub async fn cache_currencies(&mut self) -> anyhow::Result<()> {
        self.currencies = match &mut self.database {
            Some(db) => db.load_currencies().await?,
            None => AHashMap::new(),
        };

        log::info!("Cached {} currencies from database", self.general.len());
        Ok(())
    }

    /// Clears and reloads the instrument cache from the database.
    ///
    /// # Errors
    ///
    /// Returns an error if loading instruments cache fails.
    pub async fn cache_instruments(&mut self) -> anyhow::Result<()> {
        self.instruments = match &mut self.database {
            Some(db) => db.load_instruments().await?,
            None => AHashMap::new(),
        };

        log::info!("Cached {} instruments from database", self.general.len());
        Ok(())
    }

    /// Clears and reloads the synthetic instrument cache from the database.
    ///
    /// # Errors
    ///
    /// Returns an error if loading synthetic instruments cache fails.
    pub async fn cache_synthetics(&mut self) -> anyhow::Result<()> {
        self.synthetics = match &mut self.database {
            Some(db) => db.load_synthetics().await?,
            None => AHashMap::new(),
        };

        log::info!(
            "Cached {} synthetic instruments from database",
            self.general.len()
        );
        Ok(())
    }

    /// Clears and reloads the account cache from the database.
    ///
    /// # Errors
    ///
    /// Returns an error if loading accounts cache fails.
    pub async fn cache_accounts(&mut self) -> anyhow::Result<()> {
        self.accounts = match &mut self.database {
            Some(db) => db.load_accounts().await?,
            None => AHashMap::new(),
        };

        log::info!(
            "Cached {} synthetic instruments from database",
            self.general.len()
        );
        Ok(())
    }

    /// Clears and reloads the order cache from the database.
    ///
    /// # Errors
    ///
    /// Returns an error if loading orders cache fails.
    pub async fn cache_orders(&mut self) -> anyhow::Result<()> {
        self.orders = match &mut self.database {
            Some(db) => db.load_orders().await?,
            None => AHashMap::new(),
        };

        log::info!("Cached {} orders from database", self.general.len());
        Ok(())
    }

    /// Clears and reloads the position cache from the database.
    ///
    /// # Errors
    ///
    /// Returns an error if loading positions cache fails.
    pub async fn cache_positions(&mut self) -> anyhow::Result<()> {
        self.positions = match &mut self.database {
            Some(db) => db.load_positions().await?,
            None => AHashMap::new(),
        };

        log::info!("Cached {} positions from database", self.general.len());
        Ok(())
    }

    /// Clears the current cache index and re-build.
    pub fn build_index(&mut self) {
        log::debug!("Building index");

        // Index accounts
        for account_id in self.accounts.keys() {
            self.index
                .venue_account
                .insert(account_id.get_issuer(), *account_id);
        }

        // Index orders
        for (client_order_id, order) in &self.orders {
            let instrument_id = order.instrument_id();
            let venue = instrument_id.venue;
            let strategy_id = order.strategy_id();

            // 1: Build index.venue_orders -> {Venue, {ClientOrderId}}
            self.index
                .venue_orders
                .entry(venue)
                .or_default()
                .insert(*client_order_id);

            // 2: Build index.order_ids -> {VenueOrderId, ClientOrderId}
            if let Some(venue_order_id) = order.venue_order_id() {
                self.index
                    .venue_order_ids
                    .insert(venue_order_id, *client_order_id);
            }

            // 3: Build index.order_position -> {ClientOrderId, PositionId}
            if let Some(position_id) = order.position_id() {
                self.index
                    .order_position
                    .insert(*client_order_id, position_id);
            }

            // 4: Build index.order_strategy -> {ClientOrderId, StrategyId}
            self.index
                .order_strategy
                .insert(*client_order_id, order.strategy_id());

            // 5: Build index.instrument_orders -> {InstrumentId, {ClientOrderId}}
            self.index
                .instrument_orders
                .entry(instrument_id)
                .or_default()
                .insert(*client_order_id);

            // 6: Build index.strategy_orders -> {StrategyId, {ClientOrderId}}
            self.index
                .strategy_orders
                .entry(strategy_id)
                .or_default()
                .insert(*client_order_id);

            // 7: Build index.account_orders -> {AccountId, {ClientOrderId}}
            if let Some(account_id) = order.account_id() {
                self.index
                    .account_orders
                    .entry(account_id)
                    .or_default()
                    .insert(*client_order_id);
            }

            // 8: Build index.exec_algorithm_orders -> {ExecAlgorithmId, {ClientOrderId}}
            if let Some(exec_algorithm_id) = order.exec_algorithm_id() {
                self.index
                    .exec_algorithm_orders
                    .entry(exec_algorithm_id)
                    .or_default()
                    .insert(*client_order_id);
            }

            // 8: Build index.exec_spawn_orders -> {ClientOrderId, {ClientOrderId}}
            if let Some(exec_spawn_id) = order.exec_spawn_id() {
                self.index
                    .exec_spawn_orders
                    .entry(exec_spawn_id)
                    .or_default()
                    .insert(*client_order_id);
            }

            // 9: Build index.orders -> {ClientOrderId}
            self.index.orders.insert(*client_order_id);

            // 10: Build index.orders_open -> {ClientOrderId}
            if order.is_open() {
                self.index.orders_open.insert(*client_order_id);
            }

            // 11: Build index.orders_closed -> {ClientOrderId}
            if order.is_closed() {
                self.index.orders_closed.insert(*client_order_id);
            }

            // 12: Build index.orders_emulated -> {ClientOrderId}
            if let Some(emulation_trigger) = order.emulation_trigger()
                && emulation_trigger != TriggerType::NoTrigger
                && !order.is_closed()
            {
                self.index.orders_emulated.insert(*client_order_id);
            }

            // 13: Build index.orders_inflight -> {ClientOrderId}
            if order.is_inflight() {
                self.index.orders_inflight.insert(*client_order_id);
            }

            // 14: Build index.strategies -> {StrategyId}
            self.index.strategies.insert(strategy_id);

            // 15: Build index.strategies -> {ExecAlgorithmId}
            if let Some(exec_algorithm_id) = order.exec_algorithm_id() {
                self.index.exec_algorithms.insert(exec_algorithm_id);
            }
        }

        // Index positions
        for (position_id, position) in &self.positions {
            let instrument_id = position.instrument_id;
            let venue = instrument_id.venue;
            let strategy_id = position.strategy_id;

            // 1: Build index.venue_positions -> {Venue, {PositionId}}
            self.index
                .venue_positions
                .entry(venue)
                .or_default()
                .insert(*position_id);

            // 2: Build index.position_strategy -> {PositionId, StrategyId}
            self.index
                .position_strategy
                .insert(*position_id, position.strategy_id);

            // 3: Build index.position_orders -> {PositionId, {ClientOrderId}}
            self.index
                .position_orders
                .entry(*position_id)
                .or_default()
                .extend(position.client_order_ids().into_iter());

            // 4: Build index.instrument_positions -> {InstrumentId, {PositionId}}
            self.index
                .instrument_positions
                .entry(instrument_id)
                .or_default()
                .insert(*position_id);

            // 5: Build index.strategy_positions -> {StrategyId, {PositionId}}
            self.index
                .strategy_positions
                .entry(strategy_id)
                .or_default()
                .insert(*position_id);

            // 6: Build index.account_positions -> {AccountId, {PositionId}}
            self.index
                .account_positions
                .entry(position.account_id)
                .or_default()
                .insert(*position_id);

            // 7: Build index.positions -> {PositionId}
            self.index.positions.insert(*position_id);

            // 8: Build index.positions_open -> {PositionId}
            if position.is_open() {
                self.index.positions_open.insert(*position_id);
            }

            // 9: Build index.positions_closed -> {PositionId}
            if position.is_closed() {
                self.index.positions_closed.insert(*position_id);
            }

            // 10: Build index.strategies -> {StrategyId}
            self.index.strategies.insert(strategy_id);
        }
    }

    /// Returns whether the cache has a backing database.
    #[must_use]
    pub const fn has_backing(&self) -> bool {
        self.config.database.is_some()
    }

    // Calculate the unrealized profit and loss (PnL) for `position`.
    #[must_use]
    pub fn calculate_unrealized_pnl(&self, position: &Position) -> Option<Money> {
        let quote = if let Some(quote) = self.quote(&position.instrument_id) {
            quote
        } else {
            log::warn!(
                "Cannot calculate unrealized PnL for {}, no quotes for {}",
                position.id,
                position.instrument_id
            );
            return None;
        };

        // Use exit price for mark-to-market: longs exit at bid, shorts exit at ask
        let last = match position.side {
            PositionSide::Flat | PositionSide::NoPositionSide => {
                return Some(Money::new(0.0, position.settlement_currency));
            }
            PositionSide::Long => quote.bid_price,
            PositionSide::Short => quote.ask_price,
        };

        Some(position.unrealized_pnl(last))
    }

    /// Checks integrity of data within the cache.
    ///
    /// All data should be loaded from the database prior to this call.
    /// If an error is found then a log error message will also be produced.
    ///
    /// # Panics
    ///
    /// Panics if failure calling system clock.
    #[must_use]
    pub fn check_integrity(&mut self) -> bool {
        let mut error_count = 0;
        let failure = "Integrity failure";

        // Get current timestamp in microseconds
        let timestamp_us = SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .expect("Time went backwards")
            .as_micros();

        log::info!("Checking data integrity");

        // Check object caches
        for account_id in self.accounts.keys() {
            if !self
                .index
                .venue_account
                .contains_key(&account_id.get_issuer())
            {
                log::error!(
                    "{failure} in accounts: {account_id} not found in `self.index.venue_account`",
                );
                error_count += 1;
            }
        }

        for (client_order_id, order) in &self.orders {
            if !self.index.order_strategy.contains_key(client_order_id) {
                log::error!(
                    "{failure} in orders: {client_order_id} not found in `self.index.order_strategy`"
                );
                error_count += 1;
            }

            if !self.index.orders.contains(client_order_id) {
                log::error!(
                    "{failure} in orders: {client_order_id} not found in `self.index.orders`",
                );
                error_count += 1;
            }

            if order.is_inflight() && !self.index.orders_inflight.contains(client_order_id) {
                log::error!(
                    "{failure} in orders: {client_order_id} not found in `self.index.orders_inflight`",
                );
                error_count += 1;
            }

            if order.is_open() && !self.index.orders_open.contains(client_order_id) {
                log::error!(
                    "{failure} in orders: {client_order_id} not found in `self.index.orders_open`",
                );
                error_count += 1;
            }

            if order.is_closed() && !self.index.orders_closed.contains(client_order_id) {
                log::error!(
                    "{failure} in orders: {client_order_id} not found in `self.index.orders_closed`",
                );
                error_count += 1;
            }

            if let Some(exec_algorithm_id) = order.exec_algorithm_id() {
                if !self
                    .index
                    .exec_algorithm_orders
                    .contains_key(&exec_algorithm_id)
                {
                    log::error!(
                        "{failure} in orders: {client_order_id} not found in `self.index.exec_algorithm_orders`",
                    );
                    error_count += 1;
                }

                if order.exec_spawn_id().is_none()
                    && !self.index.exec_spawn_orders.contains_key(client_order_id)
                {
                    log::error!(
                        "{failure} in orders: {client_order_id} not found in `self.index.exec_spawn_orders`",
                    );
                    error_count += 1;
                }
            }
        }

        for (position_id, position) in &self.positions {
            if !self.index.position_strategy.contains_key(position_id) {
                log::error!(
                    "{failure} in positions: {position_id} not found in `self.index.position_strategy`",
                );
                error_count += 1;
            }

            if !self.index.position_orders.contains_key(position_id) {
                log::error!(
                    "{failure} in positions: {position_id} not found in `self.index.position_orders`",
                );
                error_count += 1;
            }

            if !self.index.positions.contains(position_id) {
                log::error!(
                    "{failure} in positions: {position_id} not found in `self.index.positions`",
                );
                error_count += 1;
            }

            if position.is_open() && !self.index.positions_open.contains(position_id) {
                log::error!(
                    "{failure} in positions: {position_id} not found in `self.index.positions_open`",
                );
                error_count += 1;
            }

            if position.is_closed() && !self.index.positions_closed.contains(position_id) {
                log::error!(
                    "{failure} in positions: {position_id} not found in `self.index.positions_closed`",
                );
                error_count += 1;
            }
        }

        // Check indexes
        for account_id in self.index.venue_account.values() {
            if !self.accounts.contains_key(account_id) {
                log::error!(
                    "{failure} in `index.venue_account`: {account_id} not found in `self.accounts`",
                );
                error_count += 1;
            }
        }

        for client_order_id in self.index.venue_order_ids.values() {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.venue_order_ids`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        for client_order_id in self.index.client_order_ids.keys() {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.client_order_ids`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        for client_order_id in self.index.order_position.keys() {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.order_position`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        // Check indexes
        for client_order_id in self.index.order_strategy.keys() {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.order_strategy`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        for position_id in self.index.position_strategy.keys() {
            if !self.positions.contains_key(position_id) {
                log::error!(
                    "{failure} in `index.position_strategy`: {position_id} not found in `self.positions`",
                );
                error_count += 1;
            }
        }

        for position_id in self.index.position_orders.keys() {
            if !self.positions.contains_key(position_id) {
                log::error!(
                    "{failure} in `index.position_orders`: {position_id} not found in `self.positions`",
                );
                error_count += 1;
            }
        }

        for (instrument_id, client_order_ids) in &self.index.instrument_orders {
            for client_order_id in client_order_ids {
                if !self.orders.contains_key(client_order_id) {
                    log::error!(
                        "{failure} in `index.instrument_orders`: {instrument_id} not found in `self.orders`",
                    );
                    error_count += 1;
                }
            }
        }

        for instrument_id in self.index.instrument_positions.keys() {
            if !self.index.instrument_orders.contains_key(instrument_id) {
                log::error!(
                    "{failure} in `index.instrument_positions`: {instrument_id} not found in `index.instrument_orders`",
                );
                error_count += 1;
            }
        }

        for client_order_ids in self.index.strategy_orders.values() {
            for client_order_id in client_order_ids {
                if !self.orders.contains_key(client_order_id) {
                    log::error!(
                        "{failure} in `index.strategy_orders`: {client_order_id} not found in `self.orders`",
                    );
                    error_count += 1;
                }
            }
        }

        for position_ids in self.index.strategy_positions.values() {
            for position_id in position_ids {
                if !self.positions.contains_key(position_id) {
                    log::error!(
                        "{failure} in `index.strategy_positions`: {position_id} not found in `self.positions`",
                    );
                    error_count += 1;
                }
            }
        }

        for client_order_id in &self.index.orders {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.orders`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        for client_order_id in &self.index.orders_emulated {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.orders_emulated`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        for client_order_id in &self.index.orders_inflight {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.orders_inflight`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        for client_order_id in &self.index.orders_open {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.orders_open`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        for client_order_id in &self.index.orders_closed {
            if !self.orders.contains_key(client_order_id) {
                log::error!(
                    "{failure} in `index.orders_closed`: {client_order_id} not found in `self.orders`",
                );
                error_count += 1;
            }
        }

        for position_id in &self.index.positions {
            if !self.positions.contains_key(position_id) {
                log::error!(
                    "{failure} in `index.positions`: {position_id} not found in `self.positions`",
                );
                error_count += 1;
            }
        }

        for position_id in &self.index.positions_open {
            if !self.positions.contains_key(position_id) {
                log::error!(
                    "{failure} in `index.positions_open`: {position_id} not found in `self.positions`",
                );
                error_count += 1;
            }
        }

        for position_id in &self.index.positions_closed {
            if !self.positions.contains_key(position_id) {
                log::error!(
                    "{failure} in `index.positions_closed`: {position_id} not found in `self.positions`",
                );
                error_count += 1;
            }
        }

        for strategy_id in &self.index.strategies {
            if !self.index.strategy_orders.contains_key(strategy_id) {
                log::error!(
                    "{failure} in `index.strategies`: {strategy_id} not found in `index.strategy_orders`",
                );
                error_count += 1;
            }
        }

        for exec_algorithm_id in &self.index.exec_algorithms {
            if !self
                .index
                .exec_algorithm_orders
                .contains_key(exec_algorithm_id)
            {
                log::error!(
                    "{failure} in `index.exec_algorithms`: {exec_algorithm_id} not found in `index.exec_algorithm_orders`",
                );
                error_count += 1;
            }
        }

        let total_us = SystemTime::now()
            .duration_since(UNIX_EPOCH)
            .expect("Time went backwards")
            .as_micros()
            - timestamp_us;

        if error_count == 0 {
            log::info!("Integrity check passed in {total_us}μs");
            true
        } else {
            log::error!(
                "Integrity check failed with {error_count} error{} in {total_us}μs",
                if error_count == 1 { "" } else { "s" },
            );
            false
        }
    }

    /// Checks for any residual open state and log warnings if any are found.
    ///
    ///'Open state' is considered to be open orders and open positions.
    #[must_use]
    pub fn check_residuals(&self) -> bool {
        log::debug!("Checking residuals");

        let mut residuals = false;

        // Check for any open orders
        for order in self.orders_open(None, None, None, None, None) {
            residuals = true;
            log::warn!("Residual {order}");
        }

        // Check for any open positions
        for position in self.positions_open(None, None, None, None, None) {
            residuals = true;
            log::warn!("Residual {position}");
        }

        residuals
    }

    /// Purges all closed orders from the cache that are older than `buffer_secs`.
    ///
    ///
    /// Only orders that have been closed for at least this amount of time will be purged.
    /// A value of 0 means purge all closed orders regardless of when they were closed.
    pub fn purge_closed_orders(&mut self, ts_now: UnixNanos, buffer_secs: u64) {
        log::debug!(
            "Purging closed orders{}",
            if buffer_secs > 0 {
                format!(" with buffer_secs={buffer_secs}")
            } else {
                String::new()
            }
        );

        let buffer_ns = secs_to_nanos_unchecked(buffer_secs as f64);

        let mut affected_order_list_ids: AHashSet<OrderListId> = AHashSet::new();

        'outer: for client_order_id in self.index.orders_closed.clone() {
            if let Some(order) = self.orders.get(&client_order_id)
                && order.is_closed()
                && let Some(ts_closed) = order.ts_closed()
                && ts_closed + buffer_ns <= ts_now
            {
                // Check any linked orders (contingency orders)
                if let Some(linked_order_ids) = order.linked_order_ids() {
                    for linked_order_id in linked_order_ids {
                        if let Some(linked_order) = self.orders.get(linked_order_id)
                            && linked_order.is_open()
                        {
                            // Do not purge if linked order still open
                            continue 'outer;
                        }
                    }
                }

                if let Some(order_list_id) = order.order_list_id() {
                    affected_order_list_ids.insert(order_list_id);
                }

                self.purge_order(client_order_id);
            }
        }

        for order_list_id in affected_order_list_ids {
            if let Some(order_list) = self.order_lists.get(&order_list_id) {
                let all_purged = order_list
                    .client_order_ids
                    .iter()
                    .all(|id| !self.orders.contains_key(id));

                if all_purged {
                    self.order_lists.remove(&order_list_id);
                    log::info!("Purged {order_list_id}");
                }
            }
        }
    }

    /// Purges all closed positions from the cache that are older than `buffer_secs`.
    pub fn purge_closed_positions(&mut self, ts_now: UnixNanos, buffer_secs: u64) {
        log::debug!(
            "Purging closed positions{}",
            if buffer_secs > 0 {
                format!(" with buffer_secs={buffer_secs}")
            } else {
                String::new()
            }
        );

        let buffer_ns = secs_to_nanos_unchecked(buffer_secs as f64);

        for position_id in self.index.positions_closed.clone() {
            if let Some(position) = self.positions.get(&position_id)
                && position.is_closed()
                && let Some(ts_closed) = position.ts_closed
                && ts_closed + buffer_ns <= ts_now
            {
                self.purge_position(position_id);
            }
        }
    }

    /// Purges the order with the `client_order_id` from the cache (if found).
    ///
    /// For safety, an order is prevented from being purged if it's open.
    pub fn purge_order(&mut self, client_order_id: ClientOrderId) {
        // Check if order exists and is safe to purge before removing
        let order = self.orders.get(&client_order_id).cloned();

        // Prevent purging open orders
        if let Some(ref ord) = order
            && ord.is_open()
        {
            log::warn!("Order {client_order_id} found open when purging, skipping purge");
            return;
        }

        // If order exists in cache, remove it and clean up order-specific indices
        if let Some(ref ord) = order {
            // Safe to purge
            self.orders.remove(&client_order_id);

            // Remove order from venue index
            if let Some(venue_orders) = self.index.venue_orders.get_mut(&ord.instrument_id().venue)
            {
                venue_orders.remove(&client_order_id);
            }

            // Remove venue order ID index if exists
            if let Some(venue_order_id) = ord.venue_order_id() {
                self.index.venue_order_ids.remove(&venue_order_id);
            }

            // Remove from instrument orders index
            if let Some(instrument_orders) =
                self.index.instrument_orders.get_mut(&ord.instrument_id())
            {
                instrument_orders.remove(&client_order_id);
            }

            // Remove from position orders index if associated with a position
            if let Some(position_id) = ord.position_id()
                && let Some(position_orders) = self.index.position_orders.get_mut(&position_id)
            {
                position_orders.remove(&client_order_id);
            }

            // Remove from exec algorithm orders index if it has an exec algorithm
            if let Some(exec_algorithm_id) = ord.exec_algorithm_id()
                && let Some(exec_algorithm_orders) =
                    self.index.exec_algorithm_orders.get_mut(&exec_algorithm_id)
            {
                exec_algorithm_orders.remove(&client_order_id);
            }

            // Clean up strategy orders reverse index
            if let Some(strategy_orders) = self.index.strategy_orders.get_mut(&ord.strategy_id()) {
                strategy_orders.remove(&client_order_id);
                if strategy_orders.is_empty() {
                    self.index.strategy_orders.remove(&ord.strategy_id());
                }
            }

            // Clean up account orders index
            if let Some(account_id) = ord.account_id()
                && let Some(account_orders) = self.index.account_orders.get_mut(&account_id)
            {
                account_orders.remove(&client_order_id);
                if account_orders.is_empty() {
                    self.index.account_orders.remove(&account_id);
                }
            }

            // Clean up exec spawn reverse index (if this order is a spawned child)
            if let Some(exec_spawn_id) = ord.exec_spawn_id()
                && let Some(spawn_orders) = self.index.exec_spawn_orders.get_mut(&exec_spawn_id)
            {
                spawn_orders.remove(&client_order_id);
                if spawn_orders.is_empty() {
                    self.index.exec_spawn_orders.remove(&exec_spawn_id);
                }
            }

            log::info!("Purged order {client_order_id}");
        } else {
            log::warn!("Order {client_order_id} not found when purging");
        }

        // Always clean up order indices (even if order was not in cache)
        self.index.order_position.remove(&client_order_id);
        let strategy_id = self.index.order_strategy.remove(&client_order_id);
        self.index.order_client.remove(&client_order_id);
        self.index.client_order_ids.remove(&client_order_id);

        // Clean up reverse index when order not in cache (using forward index)
        if let Some(strategy_id) = strategy_id
            && let Some(strategy_orders) = self.index.strategy_orders.get_mut(&strategy_id)
        {
            strategy_orders.remove(&client_order_id);
            if strategy_orders.is_empty() {
                self.index.strategy_orders.remove(&strategy_id);
            }
        }

        // Remove spawn parent entry if this order was a spawn root
        self.index.exec_spawn_orders.remove(&client_order_id);

        self.index.orders.remove(&client_order_id);
        self.index.orders_open.remove(&client_order_id);
        self.index.orders_closed.remove(&client_order_id);
        self.index.orders_emulated.remove(&client_order_id);
        self.index.orders_inflight.remove(&client_order_id);
        self.index.orders_pending_cancel.remove(&client_order_id);
    }

    /// Purges the position with the `position_id` from the cache (if found).
    ///
    /// For safety, a position is prevented from being purged if it's open.
    pub fn purge_position(&mut self, position_id: PositionId) {
        // Check if position exists and is safe to purge before removing
        let position = self.positions.get(&position_id).cloned();

        // Prevent purging open positions
        if let Some(ref pos) = position
            && pos.is_open()
        {
            log::warn!("Position {position_id} found open when purging, skipping purge");
            return;
        }

        // If position exists in cache, remove it and clean up position-specific indices
        if let Some(ref pos) = position {
            self.positions.remove(&position_id);

            // Remove from venue positions index
            if let Some(venue_positions) =
                self.index.venue_positions.get_mut(&pos.instrument_id.venue)
            {
                venue_positions.remove(&position_id);
            }

            // Remove from instrument positions index
            if let Some(instrument_positions) =
                self.index.instrument_positions.get_mut(&pos.instrument_id)
            {
                instrument_positions.remove(&position_id);
            }

            // Remove from strategy positions index
            if let Some(strategy_positions) =
                self.index.strategy_positions.get_mut(&pos.strategy_id)
            {
                strategy_positions.remove(&position_id);
            }

            // Remove from account positions index
            if let Some(account_positions) = self.index.account_positions.get_mut(&pos.account_id) {
                account_positions.remove(&position_id);
                if account_positions.is_empty() {
                    self.index.account_positions.remove(&pos.account_id);
                }
            }

            // Remove position ID from orders that reference it
            for client_order_id in pos.client_order_ids() {
                self.index.order_position.remove(&client_order_id);
            }

            log::info!("Purged position {position_id}");
        } else {
            log::warn!("Position {position_id} not found when purging");
        }

        // Always clean up position indices (even if position not in cache)
        self.index.position_strategy.remove(&position_id);
        self.index.position_orders.remove(&position_id);
        self.index.positions.remove(&position_id);
        self.index.positions_open.remove(&position_id);
        self.index.positions_closed.remove(&position_id);

        // Always clean up position snapshots (even if position not in cache)
        self.position_snapshots.remove(&position_id);
    }

    /// Purges all account state events which are outside the lookback window.
    ///
    /// Only events which are outside the lookback window will be purged.
    /// A value of 0 means purge all account state events.
    pub fn purge_account_events(&mut self, ts_now: UnixNanos, lookback_secs: u64) {
        log::debug!(
            "Purging account events{}",
            if lookback_secs > 0 {
                format!(" with lookback_secs={lookback_secs}")
            } else {
                String::new()
            }
        );

        for account in self.accounts.values_mut() {
            let event_count = account.event_count();
            account.purge_account_events(ts_now, lookback_secs);
            let count_diff = event_count - account.event_count();
            if count_diff > 0 {
                log::info!(
                    "Purged {} event(s) from account {}",
                    count_diff,
                    account.id()
                );
            }
        }
    }

    /// Clears the caches index.
    pub fn clear_index(&mut self) {
        self.index.clear();
        log::debug!("Cleared index");
    }

    /// Resets the cache.
    ///
    /// All stateful fields are reset to their initial value.
    pub fn reset(&mut self) {
        log::debug!("Resetting cache");

        self.general.clear();
        self.currencies.clear();
        self.instruments.clear();
        self.synthetics.clear();
        self.books.clear();
        self.own_books.clear();
        self.quotes.clear();
        self.trades.clear();
        self.mark_xrates.clear();
        self.mark_prices.clear();
        self.index_prices.clear();
        self.funding_rates.clear();
        self.bars.clear();
        self.accounts.clear();
        self.orders.clear();
        self.order_lists.clear();
        self.positions.clear();
        self.position_snapshots.clear();
        self.greeks.clear();
        self.yield_curves.clear();

        #[cfg(feature = "defi")]
        {
            self.defi.pools.clear();
            self.defi.pool_profilers.clear();
        }

        self.clear_index();

        log::info!("Reset cache");
    }

    /// Dispose of the cache which will close any underlying database adapter.
    ///
    /// If closing the database connection fails, an error is logged.
    pub fn dispose(&mut self) {
        if let Some(database) = &mut self.database
            && let Err(e) = database.close()
        {
            log::error!("Failed to close database during dispose: {e}");
        }
    }

    /// Flushes the caches database which permanently removes all persisted data.
    ///
    /// If flushing the database connection fails, an error is logged.
    pub fn flush_db(&mut self) {
        if let Some(database) = &mut self.database
            && let Err(e) = database.flush()
        {
            log::error!("Failed to flush database: {e}");
        }
    }

    /// Adds a raw bytes `value` to the cache under the `key`.
    ///
    /// The cache stores only raw bytes; interpretation is the caller's responsibility.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the entry to the backing database fails.
    pub fn add(&mut self, key: &str, value: Bytes) -> anyhow::Result<()> {
        check_valid_string_ascii(key, stringify!(key))?;
        check_predicate_false(value.is_empty(), stringify!(value))?;

        log::debug!("Adding general {key}");
        self.general.insert(key.to_string(), value.clone());

        if let Some(database) = &mut self.database {
            database.add(key.to_string(), value)?;
        }
        Ok(())
    }

    /// Adds an `OrderBook` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the order book to the backing database fails.
    pub fn add_order_book(&mut self, book: OrderBook) -> anyhow::Result<()> {
        log::debug!("Adding `OrderBook` {}", book.instrument_id);

        if self.config.save_market_data
            && let Some(database) = &mut self.database
        {
            database.add_order_book(&book)?;
        }

        self.books.insert(book.instrument_id, book);
        Ok(())
    }

    /// Adds an `OwnOrderBook` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the own order book fails.
    pub fn add_own_order_book(&mut self, own_book: OwnOrderBook) -> anyhow::Result<()> {
        log::debug!("Adding `OwnOrderBook` {}", own_book.instrument_id);

        self.own_books.insert(own_book.instrument_id, own_book);
        Ok(())
    }

    /// Adds the `mark_price` update to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the mark price to the backing database fails.
    pub fn add_mark_price(&mut self, mark_price: MarkPriceUpdate) -> anyhow::Result<()> {
        log::debug!("Adding `MarkPriceUpdate` for {}", mark_price.instrument_id);

        if self.config.save_market_data {
            // TODO: Placeholder and return Result for consistency
        }

        let mark_prices_deque = self
            .mark_prices
            .entry(mark_price.instrument_id)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));
        mark_prices_deque.push_front(mark_price);
        Ok(())
    }

    /// Adds the `index_price` update to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the index price to the backing database fails.
    pub fn add_index_price(&mut self, index_price: IndexPriceUpdate) -> anyhow::Result<()> {
        log::debug!(
            "Adding `IndexPriceUpdate` for {}",
            index_price.instrument_id
        );

        if self.config.save_market_data {
            // TODO: Placeholder and return Result for consistency
        }

        let index_prices_deque = self
            .index_prices
            .entry(index_price.instrument_id)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));
        index_prices_deque.push_front(index_price);
        Ok(())
    }

    /// Adds the `funding_rate` update to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the funding rate update to the backing database fails.
    pub fn add_funding_rate(&mut self, funding_rate: FundingRateUpdate) -> anyhow::Result<()> {
        log::debug!(
            "Adding `FundingRateUpdate` for {}",
            funding_rate.instrument_id
        );

        if self.config.save_market_data {
            // TODO: Placeholder and return Result for consistency
        }

        let funding_rates_deque = self
            .funding_rates
            .entry(funding_rate.instrument_id)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));
        funding_rates_deque.push_front(funding_rate);
        Ok(())
    }

    /// Adds the given `funding rates` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the trade ticks to the backing database fails.
    pub fn add_funding_rates(&mut self, funding_rates: &[FundingRateUpdate]) -> anyhow::Result<()> {
        check_slice_not_empty(funding_rates, stringify!(funding_rates))?;

        let instrument_id = funding_rates[0].instrument_id;
        log::debug!(
            "Adding `FundingRateUpdate`[{}] {instrument_id}",
            funding_rates.len()
        );

        if self.config.save_market_data
            && let Some(database) = &mut self.database
        {
            for funding_rate in funding_rates {
                database.add_funding_rate(funding_rate)?;
            }
        }

        let funding_rate_deque = self
            .funding_rates
            .entry(instrument_id)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));

        for funding_rate in funding_rates {
            funding_rate_deque.push_front(*funding_rate);
        }
        Ok(())
    }

    /// Adds the `quote` tick to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the quote tick to the backing database fails.
    pub fn add_quote(&mut self, quote: QuoteTick) -> anyhow::Result<()> {
        log::debug!("Adding `QuoteTick` {}", quote.instrument_id);

        if self.config.save_market_data
            && let Some(database) = &mut self.database
        {
            database.add_quote(&quote)?;
        }

        let quotes_deque = self
            .quotes
            .entry(quote.instrument_id)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));
        quotes_deque.push_front(quote);
        Ok(())
    }

    /// Adds the `quotes` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the quote ticks to the backing database fails.
    pub fn add_quotes(&mut self, quotes: &[QuoteTick]) -> anyhow::Result<()> {
        check_slice_not_empty(quotes, stringify!(quotes))?;

        let instrument_id = quotes[0].instrument_id;
        log::debug!("Adding `QuoteTick`[{}] {instrument_id}", quotes.len());

        if self.config.save_market_data
            && let Some(database) = &mut self.database
        {
            for quote in quotes {
                database.add_quote(quote)?;
            }
        }

        let quotes_deque = self
            .quotes
            .entry(instrument_id)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));

        for quote in quotes {
            quotes_deque.push_front(*quote);
        }
        Ok(())
    }

    /// Adds the `trade` tick to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the trade tick to the backing database fails.
    pub fn add_trade(&mut self, trade: TradeTick) -> anyhow::Result<()> {
        log::debug!("Adding `TradeTick` {}", trade.instrument_id);

        if self.config.save_market_data
            && let Some(database) = &mut self.database
        {
            database.add_trade(&trade)?;
        }

        let trades_deque = self
            .trades
            .entry(trade.instrument_id)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));
        trades_deque.push_front(trade);
        Ok(())
    }

    /// Adds the give `trades` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the trade ticks to the backing database fails.
    pub fn add_trades(&mut self, trades: &[TradeTick]) -> anyhow::Result<()> {
        check_slice_not_empty(trades, stringify!(trades))?;

        let instrument_id = trades[0].instrument_id;
        log::debug!("Adding `TradeTick`[{}] {instrument_id}", trades.len());

        if self.config.save_market_data
            && let Some(database) = &mut self.database
        {
            for trade in trades {
                database.add_trade(trade)?;
            }
        }

        let trades_deque = self
            .trades
            .entry(instrument_id)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));

        for trade in trades {
            trades_deque.push_front(*trade);
        }
        Ok(())
    }

    /// Adds the `bar` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the bar to the backing database fails.
    pub fn add_bar(&mut self, bar: Bar) -> anyhow::Result<()> {
        log::debug!("Adding `Bar` {}", bar.bar_type);

        if self.config.save_market_data
            && let Some(database) = &mut self.database
        {
            database.add_bar(&bar)?;
        }

        let bars = self
            .bars
            .entry(bar.bar_type)
            .or_insert_with(|| VecDeque::with_capacity(self.config.bar_capacity));
        bars.push_front(bar);
        Ok(())
    }

    /// Adds the `bars` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the bars to the backing database fails.
    pub fn add_bars(&mut self, bars: &[Bar]) -> anyhow::Result<()> {
        check_slice_not_empty(bars, stringify!(bars))?;

        let bar_type = bars[0].bar_type;
        log::debug!("Adding `Bar`[{}] {bar_type}", bars.len());

        if self.config.save_market_data
            && let Some(database) = &mut self.database
        {
            for bar in bars {
                database.add_bar(bar)?;
            }
        }

        let bars_deque = self
            .bars
            .entry(bar_type)
            .or_insert_with(|| VecDeque::with_capacity(self.config.tick_capacity));

        for bar in bars {
            bars_deque.push_front(*bar);
        }
        Ok(())
    }

    /// Adds the `greeks` data to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the greeks data to the backing database fails.
    pub fn add_greeks(&mut self, greeks: GreeksData) -> anyhow::Result<()> {
        log::debug!("Adding `GreeksData` {}", greeks.instrument_id);

        if self.config.save_market_data
            && let Some(_database) = &mut self.database
        {
            // TODO: Implement database.add_greeks(&greeks) when database adapter is updated
        }

        self.greeks.insert(greeks.instrument_id, greeks);
        Ok(())
    }

    /// Gets the greeks data for the `instrument_id`.
    pub fn greeks(&self, instrument_id: &InstrumentId) -> Option<GreeksData> {
        self.greeks.get(instrument_id).cloned()
    }

    /// Adds the `yield_curve` data to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the yield curve data to the backing database fails.
    pub fn add_yield_curve(&mut self, yield_curve: YieldCurveData) -> anyhow::Result<()> {
        log::debug!("Adding `YieldCurveData` {}", yield_curve.curve_name);

        if self.config.save_market_data
            && let Some(_database) = &mut self.database
        {
            // TODO: Implement database.add_yield_curve(&yield_curve) when database adapter is updated
        }

        self.yield_curves
            .insert(yield_curve.curve_name.clone(), yield_curve);
        Ok(())
    }

    /// Gets the yield curve for the `key`.
    pub fn yield_curve(&self, key: &str) -> Option<Box<dyn Fn(f64) -> f64>> {
        self.yield_curves.get(key).map(|curve| {
            let curve_clone = curve.clone();
            Box::new(move |expiry_in_years: f64| curve_clone.get_rate(expiry_in_years))
                as Box<dyn Fn(f64) -> f64>
        })
    }

    /// Adds the `currency` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the currency to the backing database fails.
    pub fn add_currency(&mut self, currency: Currency) -> anyhow::Result<()> {
        if self.currencies.contains_key(&currency.code) {
            return Ok(());
        }
        log::debug!("Adding `Currency` {}", currency.code);

        if let Some(database) = &mut self.database {
            database.add_currency(&currency)?;
        }

        self.currencies.insert(currency.code, currency);
        Ok(())
    }

    /// Adds the `instrument` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the instrument to the backing database fails.
    pub fn add_instrument(&mut self, instrument: InstrumentAny) -> anyhow::Result<()> {
        log::debug!("Adding `Instrument` {}", instrument.id());

        // Ensure currencies exist in cache - safe to call repeatedly as add_currency is idempotent
        if let Some(base_currency) = instrument.base_currency() {
            self.add_currency(base_currency)?;
        }
        self.add_currency(instrument.quote_currency())?;
        self.add_currency(instrument.settlement_currency())?;

        if let Some(database) = &mut self.database {
            database.add_instrument(&instrument)?;
        }

        self.instruments.insert(instrument.id(), instrument);
        Ok(())
    }

    /// Adds the `synthetic` instrument to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the synthetic instrument to the backing database fails.
    pub fn add_synthetic(&mut self, synthetic: SyntheticInstrument) -> anyhow::Result<()> {
        log::debug!("Adding `SyntheticInstrument` {}", synthetic.id);

        if let Some(database) = &mut self.database {
            database.add_synthetic(&synthetic)?;
        }

        self.synthetics.insert(synthetic.id, synthetic);
        Ok(())
    }

    /// Adds the `account` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the account to the backing database fails.
    pub fn add_account(&mut self, account: AccountAny) -> anyhow::Result<()> {
        log::debug!("Adding `Account` {}", account.id());

        if let Some(database) = &mut self.database {
            database.add_account(&account)?;
        }

        let account_id = account.id();
        self.accounts.insert(account_id, account);
        self.index
            .venue_account
            .insert(account_id.get_issuer(), account_id);
        Ok(())
    }

    /// Indexes the `client_order_id` with the `venue_order_id`.
    ///
    /// The `overwrite` parameter determines whether to overwrite any existing cached identifier.
    ///
    /// # Errors
    ///
    /// Returns an error if the existing venue order ID conflicts and overwrite is false.
    pub fn add_venue_order_id(
        &mut self,
        client_order_id: &ClientOrderId,
        venue_order_id: &VenueOrderId,
        overwrite: bool,
    ) -> anyhow::Result<()> {
        if let Some(existing_venue_order_id) = self.index.client_order_ids.get(client_order_id)
            && !overwrite
            && existing_venue_order_id != venue_order_id
        {
            anyhow::bail!(
                "Existing {existing_venue_order_id} for {client_order_id}
                    did not match the given {venue_order_id}.
                    If you are writing a test then try a different `venue_order_id`,
                    otherwise this is probably a bug."
            );
        }

        self.index
            .client_order_ids
            .insert(*client_order_id, *venue_order_id);
        self.index
            .venue_order_ids
            .insert(*venue_order_id, *client_order_id);

        Ok(())
    }

    /// Adds the `order` to the cache indexed with any given identifiers.
    ///
    /// # Parameters
    ///
    /// `override_existing`: If the added order should 'override' any existing order and replace
    /// it in the cache. This is currently used for emulated orders which are
    /// being released and transformed into another type.
    ///
    /// # Errors
    ///
    /// Returns an error if not `replace_existing` and the `order.client_order_id` is already contained in the cache.
    pub fn add_order(
        &mut self,
        order: OrderAny,
        position_id: Option<PositionId>,
        client_id: Option<ClientId>,
        replace_existing: bool,
    ) -> anyhow::Result<()> {
        let instrument_id = order.instrument_id();
        let venue = instrument_id.venue;
        let client_order_id = order.client_order_id();
        let strategy_id = order.strategy_id();
        let exec_algorithm_id = order.exec_algorithm_id();
        let exec_spawn_id = order.exec_spawn_id();

        if !replace_existing {
            check_key_not_in_map(
                &client_order_id,
                &self.orders,
                stringify!(client_order_id),
                stringify!(orders),
            )?;
        }

        log::debug!("Adding {order:?}");

        self.index.orders.insert(client_order_id);
        self.index
            .order_strategy
            .insert(client_order_id, strategy_id);
        self.index.strategies.insert(strategy_id);

        // Update venue -> orders index
        self.index
            .venue_orders
            .entry(venue)
            .or_default()
            .insert(client_order_id);

        // Update instrument -> orders index
        self.index
            .instrument_orders
            .entry(instrument_id)
            .or_default()
            .insert(client_order_id);

        // Update strategy -> orders index
        self.index
            .strategy_orders
            .entry(strategy_id)
            .or_default()
            .insert(client_order_id);

        // Update account -> orders index (if account_id known at creation)
        if let Some(account_id) = order.account_id() {
            self.index
                .account_orders
                .entry(account_id)
                .or_default()
                .insert(client_order_id);
        }

        // Update exec_algorithm -> orders index
        if let Some(exec_algorithm_id) = exec_algorithm_id {
            self.index.exec_algorithms.insert(exec_algorithm_id);

            self.index
                .exec_algorithm_orders
                .entry(exec_algorithm_id)
                .or_default()
                .insert(client_order_id);
        }

        // Update exec_spawn -> orders index
        if let Some(exec_spawn_id) = exec_spawn_id {
            self.index
                .exec_spawn_orders
                .entry(exec_spawn_id)
                .or_default()
                .insert(client_order_id);
        }

        // Update emulation index
        if let Some(emulation_trigger) = order.emulation_trigger()
            && emulation_trigger != TriggerType::NoTrigger
        {
            self.index.orders_emulated.insert(client_order_id);
        }

        // Index position ID if provided
        if let Some(position_id) = position_id {
            self.add_position_id(
                &position_id,
                &order.instrument_id().venue,
                &client_order_id,
                &strategy_id,
            )?;
        }

        // Index client ID if provided
        if let Some(client_id) = client_id {
            self.index.order_client.insert(client_order_id, client_id);
            log::debug!("Indexed {client_id:?}");
        }

        if let Some(database) = &mut self.database {
            database.add_order(&order, client_id)?;
            // TODO: Implement
            // if self.config.snapshot_orders {
            //     database.snapshot_order_state(order)?;
            // }
        }

        self.orders.insert(client_order_id, order);

        Ok(())
    }

    /// Adds the `order_list` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if the order list ID is already contained in the cache.
    pub fn add_order_list(&mut self, order_list: OrderList) -> anyhow::Result<()> {
        let order_list_id = order_list.id;
        check_key_not_in_map(
            &order_list_id,
            &self.order_lists,
            stringify!(order_list_id),
            stringify!(order_lists),
        )?;

        log::debug!("Adding {order_list:?}");
        self.order_lists.insert(order_list_id, order_list);
        Ok(())
    }

    /// Indexes the `position_id` with the other given IDs.
    ///
    /// # Errors
    ///
    /// Returns an error if indexing position ID in the backing database fails.
    pub fn add_position_id(
        &mut self,
        position_id: &PositionId,
        venue: &Venue,
        client_order_id: &ClientOrderId,
        strategy_id: &StrategyId,
    ) -> anyhow::Result<()> {
        self.index
            .order_position
            .insert(*client_order_id, *position_id);

        // Index: ClientOrderId -> PositionId
        if let Some(database) = &mut self.database {
            database.index_order_position(*client_order_id, *position_id)?;
        }

        // Index: PositionId -> StrategyId
        self.index
            .position_strategy
            .insert(*position_id, *strategy_id);

        // Index: PositionId -> set[ClientOrderId]
        self.index
            .position_orders
            .entry(*position_id)
            .or_default()
            .insert(*client_order_id);

        // Index: StrategyId -> set[PositionId]
        self.index
            .strategy_positions
            .entry(*strategy_id)
            .or_default()
            .insert(*position_id);

        // Index: Venue -> set[PositionId]
        self.index
            .venue_positions
            .entry(*venue)
            .or_default()
            .insert(*position_id);

        Ok(())
    }

    /// Adds the `position` to the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if persisting the position to the backing database fails.
    pub fn add_position(&mut self, position: Position, _oms_type: OmsType) -> anyhow::Result<()> {
        self.positions.insert(position.id, position.clone());
        self.index.positions.insert(position.id);
        self.index.positions_open.insert(position.id);
        self.index.positions_closed.remove(&position.id); // Cleanup for NETTING reopen

        log::debug!("Adding {position}");

        self.add_position_id(
            &position.id,
            &position.instrument_id.venue,
            &position.opening_order_id,
            &position.strategy_id,
        )?;

        let venue = position.instrument_id.venue;
        let venue_positions = self.index.venue_positions.entry(venue).or_default();
        venue_positions.insert(position.id);

        // Index: InstrumentId -> AHashSet
        let instrument_id = position.instrument_id;
        let instrument_positions = self
            .index
            .instrument_positions
            .entry(instrument_id)
            .or_default();
        instrument_positions.insert(position.id);

        // Index: AccountId -> AHashSet<PositionId>
        self.index
            .account_positions
            .entry(position.account_id)
            .or_default()
            .insert(position.id);

        if let Some(database) = &mut self.database {
            database.add_position(&position)?;
            // TODO: Implement position snapshots
            // if self.snapshot_positions {
            //     database.snapshot_position_state(
            //         position,
            //         position.ts_last,
            //         self.calculate_unrealized_pnl(&position),
            //     )?;
            // }
        }

        Ok(())
    }

    /// Updates the `account` in the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if updating the account in the database fails.
    pub fn update_account(&mut self, account: AccountAny) -> anyhow::Result<()> {
        let account_id = account.id();
        self.accounts.insert(account_id, account.clone());

        if let Some(database) = &mut self.database {
            database.update_account(&account)?;
        }
        Ok(())
    }

    /// Updates the `order` in the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if updating the order in the database fails.
    pub fn update_order(&mut self, order: &OrderAny) -> anyhow::Result<()> {
        let client_order_id = order.client_order_id();

        // Update venue order ID
        if let Some(venue_order_id) = order.venue_order_id() {
            // If the order is being modified then we allow a changing `VenueOrderId` to accommodate
            // venues which use a cancel+replace update strategy.
            if !self.index.venue_order_ids.contains_key(&venue_order_id) {
                // TODO: If the last event was `OrderUpdated` then overwrite should be true
                self.add_venue_order_id(&order.client_order_id(), &venue_order_id, false)?;
            }
        }

        // Update in-flight state
        if order.is_inflight() {
            self.index.orders_inflight.insert(client_order_id);
        } else {
            self.index.orders_inflight.remove(&client_order_id);
        }

        // Update open/closed state
        if order.is_open() {
            self.index.orders_closed.remove(&client_order_id);
            self.index.orders_open.insert(client_order_id);
        } else if order.is_closed() {
            self.index.orders_open.remove(&client_order_id);
            self.index.orders_pending_cancel.remove(&client_order_id);
            self.index.orders_closed.insert(client_order_id);
        }

        // Update emulation index
        if let Some(emulation_trigger) = order.emulation_trigger()
            && emulation_trigger != TriggerType::NoTrigger
            && !order.is_closed()
        {
            self.index.orders_emulated.insert(client_order_id);
        } else {
            self.index.orders_emulated.remove(&client_order_id);
        }

        // Update account orders index when account_id becomes available
        if let Some(account_id) = order.account_id() {
            self.index
                .account_orders
                .entry(account_id)
                .or_default()
                .insert(client_order_id);
        }

        // Update own book
        if self.own_order_book(&order.instrument_id()).is_some()
            && should_handle_own_book_order(order)
        {
            self.update_own_order_book(order);
        }

        if let Some(database) = &mut self.database {
            database.update_order(order.last_event())?;
            // TODO: Implement order snapshots
            // if self.snapshot_orders {
            //     database.snapshot_order_state(order)?;
            // }
        }

        // update the order in the cache
        self.orders.insert(client_order_id, order.clone());

        Ok(())
    }

    /// Updates the `order` as pending cancel locally.
    pub fn update_order_pending_cancel_local(&mut self, order: &OrderAny) {
        self.index
            .orders_pending_cancel
            .insert(order.client_order_id());
    }

    /// Updates the `position` in the cache.
    ///
    /// # Errors
    ///
    /// Returns an error if updating the position in the database fails.
    pub fn update_position(&mut self, position: &Position) -> anyhow::Result<()> {
        // Update open/closed state

        if position.is_open() {
            self.index.positions_open.insert(position.id);
            self.index.positions_closed.remove(&position.id);
        } else {
            self.index.positions_closed.insert(position.id);
            self.index.positions_open.remove(&position.id);
        }

        if let Some(database) = &mut self.database {
            database.update_position(position)?;
            // TODO: Implement order snapshots
            // if self.snapshot_orders {
            //     database.snapshot_order_state(order)?;
            // }
        }

        self.positions.insert(position.id, position.clone());

        Ok(())
    }

    /// Creates a snapshot of the `position` by cloning it, assigning a new ID,
    /// serializing it, and storing it in the position snapshots.
    ///
    /// # Errors
    ///
    /// Returns an error if serializing or storing the position snapshot fails.
    pub fn snapshot_position(&mut self, position: &Position) -> anyhow::Result<()> {
        let position_id = position.id;

        let mut copied_position = position.clone();
        let new_id = format!("{}-{}", position_id.as_str(), UUID4::new());
        copied_position.id = PositionId::new(new_id);

        // Serialize the position (TODO: temporarily just to JSON to remove a dependency)
        let position_serialized = serde_json::to_vec(&copied_position)?;

        let snapshots: Option<&Bytes> = self.position_snapshots.get(&position_id);
        let new_snapshots = match snapshots {
            Some(existing_snapshots) => {
                let mut combined = existing_snapshots.to_vec();
                combined.extend(position_serialized);
                Bytes::from(combined)
            }
            None => Bytes::from(position_serialized),
        };
        self.position_snapshots.insert(position_id, new_snapshots);

        log::debug!("Snapshot {copied_position}");
        Ok(())
    }

    /// Creates a snapshot of the `position` state in the database.
    ///
    /// # Errors
    ///
    /// Returns an error if snapshotting the position state fails.
    pub fn snapshot_position_state(
        &mut self,
        position: &Position,
        // ts_snapshot: u64,
        // unrealized_pnl: Option<Money>,
        open_only: Option<bool>,
    ) -> anyhow::Result<()> {
        let open_only = open_only.unwrap_or(true);

        if open_only && !position.is_open() {
            return Ok(());
        }

        if let Some(database) = &mut self.database {
            database.snapshot_position_state(position).map_err(|e| {
                log::error!(
                    "Failed to snapshot position state for {}: {e:?}",
                    position.id
                );
                e
            })?;
        } else {
            log::warn!(
                "Cannot snapshot position state for {} (no database configured)",
                position.id
            );
        }

        // Ok(())
        todo!()
    }

    /// Gets the OMS type for the `position_id`.
    #[must_use]
    pub fn oms_type(&self, position_id: &PositionId) -> Option<OmsType> {
        // Get OMS type from the index
        if self.index.position_strategy.contains_key(position_id) {
            // For now, we'll default to NETTING
            // TODO: Store and retrieve actual OMS type per position
            Some(OmsType::Netting)
        } else {
            None
        }
    }

    /// Gets position snapshot bytes for the `position_id`.
    #[must_use]
    pub fn position_snapshot_bytes(&self, position_id: &PositionId) -> Option<Vec<u8>> {
        self.position_snapshots.get(position_id).map(|b| b.to_vec())
    }

    /// Gets position snapshot IDs for the `instrument_id`.
    #[must_use]
    pub fn position_snapshot_ids(&self, instrument_id: &InstrumentId) -> AHashSet<PositionId> {
        // Get snapshot position IDs that match the instrument
        let mut result = AHashSet::new();
        for (position_id, _) in &self.position_snapshots {
            // Check if this position is for the requested instrument
            if let Some(position) = self.positions.get(position_id)
                && position.instrument_id == *instrument_id
            {
                result.insert(*position_id);
            }
        }
        result
    }

    /// Snapshots the `order` state in the database.
    ///
    /// # Errors
    ///
    /// Returns an error if snapshotting the order state fails.
    pub fn snapshot_order_state(&self, order: &OrderAny) -> anyhow::Result<()> {
        let database = if let Some(database) = &self.database {
            database
        } else {
            log::warn!(
                "Cannot snapshot order state for {} (no database configured)",
                order.client_order_id()
            );
            return Ok(());
        };

        database.snapshot_order_state(order)
    }

    // -- IDENTIFIER QUERIES ----------------------------------------------------------------------

    fn build_order_query_filter_set(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> Option<AHashSet<ClientOrderId>> {
        let mut query: Option<AHashSet<ClientOrderId>> = None;

        if let Some(venue) = venue {
            query = Some(
                self.index
                    .venue_orders
                    .get(venue)
                    .cloned()
                    .unwrap_or_default(),
            );
        }

        if let Some(instrument_id) = instrument_id {
            let instrument_orders = self
                .index
                .instrument_orders
                .get(instrument_id)
                .cloned()
                .unwrap_or_default();

            if let Some(existing_query) = &mut query {
                *existing_query = existing_query
                    .intersection(&instrument_orders)
                    .copied()
                    .collect();
            } else {
                query = Some(instrument_orders);
            }
        }

        if let Some(strategy_id) = strategy_id {
            let strategy_orders = self
                .index
                .strategy_orders
                .get(strategy_id)
                .cloned()
                .unwrap_or_default();

            if let Some(existing_query) = &mut query {
                *existing_query = existing_query
                    .intersection(&strategy_orders)
                    .copied()
                    .collect();
            } else {
                query = Some(strategy_orders);
            }
        }

        if let Some(account_id) = account_id {
            let account_orders = self
                .index
                .account_orders
                .get(account_id)
                .cloned()
                .unwrap_or_default();

            if let Some(existing_query) = &mut query {
                *existing_query = existing_query
                    .intersection(&account_orders)
                    .copied()
                    .collect();
            } else {
                query = Some(account_orders);
            }
        }

        query
    }

    fn build_position_query_filter_set(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> Option<AHashSet<PositionId>> {
        let mut query: Option<AHashSet<PositionId>> = None;

        if let Some(venue) = venue {
            query = Some(
                self.index
                    .venue_positions
                    .get(venue)
                    .cloned()
                    .unwrap_or_default(),
            );
        }

        if let Some(instrument_id) = instrument_id {
            let instrument_positions = self
                .index
                .instrument_positions
                .get(instrument_id)
                .cloned()
                .unwrap_or_default();

            if let Some(existing_query) = query {
                query = Some(
                    existing_query
                        .intersection(&instrument_positions)
                        .copied()
                        .collect(),
                );
            } else {
                query = Some(instrument_positions);
            }
        }

        if let Some(strategy_id) = strategy_id {
            let strategy_positions = self
                .index
                .strategy_positions
                .get(strategy_id)
                .cloned()
                .unwrap_or_default();

            if let Some(existing_query) = query {
                query = Some(
                    existing_query
                        .intersection(&strategy_positions)
                        .copied()
                        .collect(),
                );
            } else {
                query = Some(strategy_positions);
            }
        }

        if let Some(account_id) = account_id {
            let account_positions = self
                .index
                .account_positions
                .get(account_id)
                .cloned()
                .unwrap_or_default();

            if let Some(existing_query) = query {
                query = Some(
                    existing_query
                        .intersection(&account_positions)
                        .copied()
                        .collect(),
                );
            } else {
                query = Some(account_positions);
            }
        }

        query
    }

    /// Retrieves orders corresponding to the `client_order_ids`, optionally filtering by `side`.
    ///
    /// # Panics
    ///
    /// Panics if any `client_order_id` in the set is not found in the cache.
    fn get_orders_for_ids(
        &self,
        client_order_ids: &AHashSet<ClientOrderId>,
        side: Option<OrderSide>,
    ) -> Vec<&OrderAny> {
        let side = side.unwrap_or(OrderSide::NoOrderSide);
        let mut orders = Vec::new();

        for client_order_id in client_order_ids {
            let order = self
                .orders
                .get(client_order_id)
                .unwrap_or_else(|| panic!("Order {client_order_id} not found"));

            if side == OrderSide::NoOrderSide || side == order.order_side() {
                orders.push(order);
            }
        }

        orders
    }

    /// Retrieves positions corresponding to the `position_ids`, optionally filtering by `side`.
    ///
    /// # Panics
    ///
    /// Panics if any `position_id` in the set is not found in the cache.
    fn get_positions_for_ids(
        &self,
        position_ids: &AHashSet<PositionId>,
        side: Option<PositionSide>,
    ) -> Vec<&Position> {
        let side = side.unwrap_or(PositionSide::NoPositionSide);
        let mut positions = Vec::new();

        for position_id in position_ids {
            let position = self
                .positions
                .get(position_id)
                .unwrap_or_else(|| panic!("Position {position_id} not found"));

            if side == PositionSide::NoPositionSide || side == position.side {
                positions.push(position);
            }
        }

        positions
    }

    /// Returns the `ClientOrderId`s of all orders.
    #[must_use]
    pub fn client_order_ids(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> AHashSet<ClientOrderId> {
        let query =
            self.build_order_query_filter_set(venue, instrument_id, strategy_id, account_id);
        match query {
            Some(query) => self.index.orders.intersection(&query).copied().collect(),
            None => self.index.orders.clone(),
        }
    }

    /// Returns the `ClientOrderId`s of all open orders.
    #[must_use]
    pub fn client_order_ids_open(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> AHashSet<ClientOrderId> {
        let query =
            self.build_order_query_filter_set(venue, instrument_id, strategy_id, account_id);
        match query {
            Some(query) => self
                .index
                .orders_open
                .intersection(&query)
                .copied()
                .collect(),
            None => self.index.orders_open.clone(),
        }
    }

    /// Returns the `ClientOrderId`s of all closed orders.
    #[must_use]
    pub fn client_order_ids_closed(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> AHashSet<ClientOrderId> {
        let query =
            self.build_order_query_filter_set(venue, instrument_id, strategy_id, account_id);
        match query {
            Some(query) => self
                .index
                .orders_closed
                .intersection(&query)
                .copied()
                .collect(),
            None => self.index.orders_closed.clone(),
        }
    }

    /// Returns the `ClientOrderId`s of all emulated orders.
    #[must_use]
    pub fn client_order_ids_emulated(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> AHashSet<ClientOrderId> {
        let query =
            self.build_order_query_filter_set(venue, instrument_id, strategy_id, account_id);
        match query {
            Some(query) => self
                .index
                .orders_emulated
                .intersection(&query)
                .copied()
                .collect(),
            None => self.index.orders_emulated.clone(),
        }
    }

    /// Returns the `ClientOrderId`s of all in-flight orders.
    #[must_use]
    pub fn client_order_ids_inflight(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> AHashSet<ClientOrderId> {
        let query =
            self.build_order_query_filter_set(venue, instrument_id, strategy_id, account_id);
        match query {
            Some(query) => self
                .index
                .orders_inflight
                .intersection(&query)
                .copied()
                .collect(),
            None => self.index.orders_inflight.clone(),
        }
    }

    /// Returns `PositionId`s of all positions.
    #[must_use]
    pub fn position_ids(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> AHashSet<PositionId> {
        let query =
            self.build_position_query_filter_set(venue, instrument_id, strategy_id, account_id);
        match query {
            Some(query) => self.index.positions.intersection(&query).copied().collect(),
            None => self.index.positions.clone(),
        }
    }

    /// Returns the `PositionId`s of all open positions.
    #[must_use]
    pub fn position_open_ids(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> AHashSet<PositionId> {
        let query =
            self.build_position_query_filter_set(venue, instrument_id, strategy_id, account_id);
        match query {
            Some(query) => self
                .index
                .positions_open
                .intersection(&query)
                .copied()
                .collect(),
            None => self.index.positions_open.clone(),
        }
    }

    /// Returns the `PositionId`s of all closed positions.
    #[must_use]
    pub fn position_closed_ids(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> AHashSet<PositionId> {
        let query =
            self.build_position_query_filter_set(venue, instrument_id, strategy_id, account_id);
        match query {
            Some(query) => self
                .index
                .positions_closed
                .intersection(&query)
                .copied()
                .collect(),
            None => self.index.positions_closed.clone(),
        }
    }

    /// Returns the `ComponentId`s of all actors.
    #[must_use]
    pub fn actor_ids(&self) -> AHashSet<ComponentId> {
        self.index.actors.clone()
    }

    /// Returns the `StrategyId`s of all strategies.
    #[must_use]
    pub fn strategy_ids(&self) -> AHashSet<StrategyId> {
        self.index.strategies.clone()
    }

    /// Returns the `ExecAlgorithmId`s of all execution algorithms.
    #[must_use]
    pub fn exec_algorithm_ids(&self) -> AHashSet<ExecAlgorithmId> {
        self.index.exec_algorithms.clone()
    }

    // -- ORDER QUERIES ---------------------------------------------------------------------------

    /// Gets a reference to the order with the `client_order_id` (if found).
    #[must_use]
    pub fn order(&self, client_order_id: &ClientOrderId) -> Option<&OrderAny> {
        self.orders.get(client_order_id)
    }

    /// Gets cloned orders for the given `client_order_ids`, logging an error for any missing.
    #[must_use]
    pub fn orders_for_ids(
        &self,
        client_order_ids: &[ClientOrderId],
        context: &dyn Display,
    ) -> Vec<OrderAny> {
        let mut orders = Vec::with_capacity(client_order_ids.len());
        for id in client_order_ids {
            match self.orders.get(id) {
                Some(order) => orders.push(order.clone()),
                None => log::error!("Order {id} not found in cache for {context}"),
            }
        }
        orders
    }

    /// Gets a reference to the order with the `client_order_id` (if found).
    #[must_use]
    pub fn mut_order(&mut self, client_order_id: &ClientOrderId) -> Option<&mut OrderAny> {
        self.orders.get_mut(client_order_id)
    }

    /// Gets a reference to the client order ID for the `venue_order_id` (if found).
    #[must_use]
    pub fn client_order_id(&self, venue_order_id: &VenueOrderId) -> Option<&ClientOrderId> {
        self.index.venue_order_ids.get(venue_order_id)
    }

    /// Gets a reference to the venue order ID for the `client_order_id` (if found).
    #[must_use]
    pub fn venue_order_id(&self, client_order_id: &ClientOrderId) -> Option<&VenueOrderId> {
        self.index.client_order_ids.get(client_order_id)
    }

    /// Gets a reference to the client ID indexed for then `client_order_id` (if found).
    #[must_use]
    pub fn client_id(&self, client_order_id: &ClientOrderId) -> Option<&ClientId> {
        self.index.order_client.get(client_order_id)
    }

    /// Returns references to all orders matching the optional filter parameters.
    #[must_use]
    pub fn orders(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> Vec<&OrderAny> {
        let client_order_ids = self.client_order_ids(venue, instrument_id, strategy_id, account_id);
        self.get_orders_for_ids(&client_order_ids, side)
    }

    /// Returns references to all open orders matching the optional filter parameters.
    #[must_use]
    pub fn orders_open(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> Vec<&OrderAny> {
        let client_order_ids =
            self.client_order_ids_open(venue, instrument_id, strategy_id, account_id);
        self.get_orders_for_ids(&client_order_ids, side)
    }

    /// Returns references to all closed orders matching the optional filter parameters.
    #[must_use]
    pub fn orders_closed(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> Vec<&OrderAny> {
        let client_order_ids =
            self.client_order_ids_closed(venue, instrument_id, strategy_id, account_id);
        self.get_orders_for_ids(&client_order_ids, side)
    }

    /// Returns references to all emulated orders matching the optional filter parameters.
    #[must_use]
    pub fn orders_emulated(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> Vec<&OrderAny> {
        let client_order_ids =
            self.client_order_ids_emulated(venue, instrument_id, strategy_id, account_id);
        self.get_orders_for_ids(&client_order_ids, side)
    }

    /// Returns references to all in-flight orders matching the optional filter parameters.
    #[must_use]
    pub fn orders_inflight(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> Vec<&OrderAny> {
        let client_order_ids =
            self.client_order_ids_inflight(venue, instrument_id, strategy_id, account_id);
        self.get_orders_for_ids(&client_order_ids, side)
    }

    /// Returns references to all orders for the `position_id`.
    #[must_use]
    pub fn orders_for_position(&self, position_id: &PositionId) -> Vec<&OrderAny> {
        let client_order_ids = self.index.position_orders.get(position_id);
        match client_order_ids {
            Some(client_order_ids) => {
                self.get_orders_for_ids(&client_order_ids.iter().copied().collect(), None)
            }
            None => Vec::new(),
        }
    }

    /// Returns whether an order with the `client_order_id` exists.
    #[must_use]
    pub fn order_exists(&self, client_order_id: &ClientOrderId) -> bool {
        self.index.orders.contains(client_order_id)
    }

    /// Returns whether an order with the `client_order_id` is open.
    #[must_use]
    pub fn is_order_open(&self, client_order_id: &ClientOrderId) -> bool {
        self.index.orders_open.contains(client_order_id)
    }

    /// Returns whether an order with the `client_order_id` is closed.
    #[must_use]
    pub fn is_order_closed(&self, client_order_id: &ClientOrderId) -> bool {
        self.index.orders_closed.contains(client_order_id)
    }

    /// Returns whether an order with the `client_order_id` is emulated.
    #[must_use]
    pub fn is_order_emulated(&self, client_order_id: &ClientOrderId) -> bool {
        self.index.orders_emulated.contains(client_order_id)
    }

    /// Returns whether an order with the `client_order_id` is in-flight.
    #[must_use]
    pub fn is_order_inflight(&self, client_order_id: &ClientOrderId) -> bool {
        self.index.orders_inflight.contains(client_order_id)
    }

    /// Returns whether an order with the `client_order_id` is `PENDING_CANCEL` locally.
    #[must_use]
    pub fn is_order_pending_cancel_local(&self, client_order_id: &ClientOrderId) -> bool {
        self.index.orders_pending_cancel.contains(client_order_id)
    }

    /// Returns the count of all open orders.
    #[must_use]
    pub fn orders_open_count(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> usize {
        self.orders_open(venue, instrument_id, strategy_id, account_id, side)
            .len()
    }

    /// Returns the count of all closed orders.
    #[must_use]
    pub fn orders_closed_count(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> usize {
        self.orders_closed(venue, instrument_id, strategy_id, account_id, side)
            .len()
    }

    /// Returns the count of all emulated orders.
    #[must_use]
    pub fn orders_emulated_count(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> usize {
        self.orders_emulated(venue, instrument_id, strategy_id, account_id, side)
            .len()
    }

    /// Returns the count of all in-flight orders.
    #[must_use]
    pub fn orders_inflight_count(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> usize {
        self.orders_inflight(venue, instrument_id, strategy_id, account_id, side)
            .len()
    }

    /// Returns the count of all orders.
    #[must_use]
    pub fn orders_total_count(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> usize {
        self.orders(venue, instrument_id, strategy_id, account_id, side)
            .len()
    }

    /// Returns the order list for the `order_list_id`.
    #[must_use]
    pub fn order_list(&self, order_list_id: &OrderListId) -> Option<&OrderList> {
        self.order_lists.get(order_list_id)
    }

    /// Returns all order lists matching the optional filter parameters.
    #[must_use]
    pub fn order_lists(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
    ) -> Vec<&OrderList> {
        let mut order_lists = self.order_lists.values().collect::<Vec<&OrderList>>();

        if let Some(venue) = venue {
            order_lists.retain(|ol| &ol.instrument_id.venue == venue);
        }

        if let Some(instrument_id) = instrument_id {
            order_lists.retain(|ol| &ol.instrument_id == instrument_id);
        }

        if let Some(strategy_id) = strategy_id {
            order_lists.retain(|ol| &ol.strategy_id == strategy_id);
        }

        if let Some(account_id) = account_id {
            order_lists.retain(|ol| {
                ol.client_order_ids.iter().any(|client_order_id| {
                    self.orders
                        .get(client_order_id)
                        .is_some_and(|order| order.account_id().as_ref() == Some(account_id))
                })
            });
        }

        order_lists
    }

    /// Returns whether an order list with the `order_list_id` exists.
    #[must_use]
    pub fn order_list_exists(&self, order_list_id: &OrderListId) -> bool {
        self.order_lists.contains_key(order_list_id)
    }

    // -- EXEC ALGORITHM QUERIES ------------------------------------------------------------------

    /// Returns references to all orders associated with the `exec_algorithm_id` matching the
    /// optional filter parameters.
    #[must_use]
    pub fn orders_for_exec_algorithm(
        &self,
        exec_algorithm_id: &ExecAlgorithmId,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<OrderSide>,
    ) -> Vec<&OrderAny> {
        let query =
            self.build_order_query_filter_set(venue, instrument_id, strategy_id, account_id);
        let exec_algorithm_order_ids = self.index.exec_algorithm_orders.get(exec_algorithm_id);

        if let Some(query) = query
            && let Some(exec_algorithm_order_ids) = exec_algorithm_order_ids
        {
            let _exec_algorithm_order_ids = exec_algorithm_order_ids.intersection(&query);
        }

        if let Some(exec_algorithm_order_ids) = exec_algorithm_order_ids {
            self.get_orders_for_ids(exec_algorithm_order_ids, side)
        } else {
            Vec::new()
        }
    }

    /// Returns references to all orders with the `exec_spawn_id`.
    #[must_use]
    pub fn orders_for_exec_spawn(&self, exec_spawn_id: &ClientOrderId) -> Vec<&OrderAny> {
        self.get_orders_for_ids(
            self.index
                .exec_spawn_orders
                .get(exec_spawn_id)
                .unwrap_or(&AHashSet::new()),
            None,
        )
    }

    /// Returns the total order quantity for the `exec_spawn_id`.
    #[must_use]
    pub fn exec_spawn_total_quantity(
        &self,
        exec_spawn_id: &ClientOrderId,
        active_only: bool,
    ) -> Option<Quantity> {
        let exec_spawn_orders = self.orders_for_exec_spawn(exec_spawn_id);

        let mut total_quantity: Option<Quantity> = None;

        for spawn_order in exec_spawn_orders {
            if active_only && spawn_order.is_closed() {
                continue;
            }

            match total_quantity.as_mut() {
                Some(total) => *total = *total + spawn_order.quantity(),
                None => total_quantity = Some(spawn_order.quantity()),
            }
        }

        total_quantity
    }

    /// Returns the total filled quantity for all orders with the `exec_spawn_id`.
    #[must_use]
    pub fn exec_spawn_total_filled_qty(
        &self,
        exec_spawn_id: &ClientOrderId,
        active_only: bool,
    ) -> Option<Quantity> {
        let exec_spawn_orders = self.orders_for_exec_spawn(exec_spawn_id);

        let mut total_quantity: Option<Quantity> = None;

        for spawn_order in exec_spawn_orders {
            if active_only && spawn_order.is_closed() {
                continue;
            }

            match total_quantity.as_mut() {
                Some(total) => *total = *total + spawn_order.filled_qty(),
                None => total_quantity = Some(spawn_order.filled_qty()),
            }
        }

        total_quantity
    }

    /// Returns the total leaves quantity for all orders with the `exec_spawn_id`.
    #[must_use]
    pub fn exec_spawn_total_leaves_qty(
        &self,
        exec_spawn_id: &ClientOrderId,
        active_only: bool,
    ) -> Option<Quantity> {
        let exec_spawn_orders = self.orders_for_exec_spawn(exec_spawn_id);

        let mut total_quantity: Option<Quantity> = None;

        for spawn_order in exec_spawn_orders {
            if active_only && spawn_order.is_closed() {
                continue;
            }

            match total_quantity.as_mut() {
                Some(total) => *total = *total + spawn_order.leaves_qty(),
                None => total_quantity = Some(spawn_order.leaves_qty()),
            }
        }

        total_quantity
    }

    // -- POSITION QUERIES ------------------------------------------------------------------------

    /// Returns a reference to the position with the `position_id` (if found).
    #[must_use]
    pub fn position(&self, position_id: &PositionId) -> Option<&Position> {
        self.positions.get(position_id)
    }

    /// Returns a reference to the position for the `client_order_id` (if found).
    #[must_use]
    pub fn position_for_order(&self, client_order_id: &ClientOrderId) -> Option<&Position> {
        self.index
            .order_position
            .get(client_order_id)
            .and_then(|position_id| self.positions.get(position_id))
    }

    /// Returns a reference to the position ID for the `client_order_id` (if found).
    #[must_use]
    pub fn position_id(&self, client_order_id: &ClientOrderId) -> Option<&PositionId> {
        self.index.order_position.get(client_order_id)
    }

    /// Returns a reference to all positions matching the optional filter parameters.
    #[must_use]
    pub fn positions(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<PositionSide>,
    ) -> Vec<&Position> {
        let position_ids = self.position_ids(venue, instrument_id, strategy_id, account_id);
        self.get_positions_for_ids(&position_ids, side)
    }

    /// Returns a reference to all open positions matching the optional filter parameters.
    #[must_use]
    pub fn positions_open(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<PositionSide>,
    ) -> Vec<&Position> {
        let position_ids = self.position_open_ids(venue, instrument_id, strategy_id, account_id);
        self.get_positions_for_ids(&position_ids, side)
    }

    /// Returns a reference to all closed positions matching the optional filter parameters.
    #[must_use]
    pub fn positions_closed(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<PositionSide>,
    ) -> Vec<&Position> {
        let position_ids = self.position_closed_ids(venue, instrument_id, strategy_id, account_id);
        self.get_positions_for_ids(&position_ids, side)
    }

    /// Returns whether a position with the `position_id` exists.
    #[must_use]
    pub fn position_exists(&self, position_id: &PositionId) -> bool {
        self.index.positions.contains(position_id)
    }

    /// Returns whether a position with the `position_id` is open.
    #[must_use]
    pub fn is_position_open(&self, position_id: &PositionId) -> bool {
        self.index.positions_open.contains(position_id)
    }

    /// Returns whether a position with the `position_id` is closed.
    #[must_use]
    pub fn is_position_closed(&self, position_id: &PositionId) -> bool {
        self.index.positions_closed.contains(position_id)
    }

    /// Returns the count of all open positions.
    #[must_use]
    pub fn positions_open_count(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<PositionSide>,
    ) -> usize {
        self.positions_open(venue, instrument_id, strategy_id, account_id, side)
            .len()
    }

    /// Returns the count of all closed positions.
    #[must_use]
    pub fn positions_closed_count(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<PositionSide>,
    ) -> usize {
        self.positions_closed(venue, instrument_id, strategy_id, account_id, side)
            .len()
    }

    /// Returns the count of all positions.
    #[must_use]
    pub fn positions_total_count(
        &self,
        venue: Option<&Venue>,
        instrument_id: Option<&InstrumentId>,
        strategy_id: Option<&StrategyId>,
        account_id: Option<&AccountId>,
        side: Option<PositionSide>,
    ) -> usize {
        self.positions(venue, instrument_id, strategy_id, account_id, side)
            .len()
    }

    // -- STRATEGY QUERIES ------------------------------------------------------------------------

    /// Gets a reference to the strategy ID for the `client_order_id` (if found).
    #[must_use]
    pub fn strategy_id_for_order(&self, client_order_id: &ClientOrderId) -> Option<&StrategyId> {
        self.index.order_strategy.get(client_order_id)
    }

    /// Gets a reference to the strategy ID for the `position_id` (if found).
    #[must_use]
    pub fn strategy_id_for_position(&self, position_id: &PositionId) -> Option<&StrategyId> {
        self.index.position_strategy.get(position_id)
    }

    // -- GENERAL ---------------------------------------------------------------------------------

    /// Gets a reference to the general value for the `key` (if found).
    ///
    /// # Errors
    ///
    /// Returns an error if the `key` is invalid.
    pub fn get(&self, key: &str) -> anyhow::Result<Option<&Bytes>> {
        check_valid_string_ascii(key, stringify!(key))?;

        Ok(self.general.get(key))
    }

    // -- DATA QUERIES ----------------------------------------------------------------------------

    /// Returns the price for the `instrument_id` and `price_type` (if found).
    #[must_use]
    pub fn price(&self, instrument_id: &InstrumentId, price_type: PriceType) -> Option<Price> {
        match price_type {
            PriceType::Bid => self
                .quotes
                .get(instrument_id)
                .and_then(|quotes| quotes.front().map(|quote| quote.bid_price)),
            PriceType::Ask => self
                .quotes
                .get(instrument_id)
                .and_then(|quotes| quotes.front().map(|quote| quote.ask_price)),
            PriceType::Mid => self.quotes.get(instrument_id).and_then(|quotes| {
                quotes.front().map(|quote| {
                    Price::new(
                        f64::midpoint(quote.ask_price.as_f64(), quote.bid_price.as_f64()),
                        quote.bid_price.precision + 1,
                    )
                })
            }),
            PriceType::Last => self
                .trades
                .get(instrument_id)
                .and_then(|trades| trades.front().map(|trade| trade.price)),
            PriceType::Mark => self
                .mark_prices
                .get(instrument_id)
                .and_then(|marks| marks.front().map(|mark| mark.value)),
        }
    }

    /// Gets all quotes for the `instrument_id`.
    #[must_use]
    pub fn quotes(&self, instrument_id: &InstrumentId) -> Option<Vec<QuoteTick>> {
        self.quotes
            .get(instrument_id)
            .map(|quotes| quotes.iter().copied().collect())
    }

    /// Gets all trades for the `instrument_id`.
    #[must_use]
    pub fn trades(&self, instrument_id: &InstrumentId) -> Option<Vec<TradeTick>> {
        self.trades
            .get(instrument_id)
            .map(|trades| trades.iter().copied().collect())
    }

    /// Gets all mark price updates for the `instrument_id`.
    #[must_use]
    pub fn mark_prices(&self, instrument_id: &InstrumentId) -> Option<Vec<MarkPriceUpdate>> {
        self.mark_prices
            .get(instrument_id)
            .map(|mark_prices| mark_prices.iter().copied().collect())
    }

    /// Gets all index price updates for the `instrument_id`.
    #[must_use]
    pub fn index_prices(&self, instrument_id: &InstrumentId) -> Option<Vec<IndexPriceUpdate>> {
        self.index_prices
            .get(instrument_id)
            .map(|index_prices| index_prices.iter().copied().collect())
    }

    /// Gets all funding rate updates for the `instrument_id`.
    #[must_use]
    pub fn funding_rates(&self, instrument_id: &InstrumentId) -> Option<Vec<FundingRateUpdate>> {
        self.funding_rates
            .get(instrument_id)
            .map(|funding_rates| funding_rates.iter().copied().collect())
    }

    /// Gets all bars for the `bar_type`.
    #[must_use]
    pub fn bars(&self, bar_type: &BarType) -> Option<Vec<Bar>> {
        self.bars
            .get(bar_type)
            .map(|bars| bars.iter().copied().collect())
    }

    /// Gets a reference to the order book for the `instrument_id`.
    #[must_use]
    pub fn order_book(&self, instrument_id: &InstrumentId) -> Option<&OrderBook> {
        self.books.get(instrument_id)
    }

    /// Gets a reference to the order book for the `instrument_id`.
    #[must_use]
    pub fn order_book_mut(&mut self, instrument_id: &InstrumentId) -> Option<&mut OrderBook> {
        self.books.get_mut(instrument_id)
    }

    /// Gets a reference to the own order book for the `instrument_id`.
    #[must_use]
    pub fn own_order_book(&self, instrument_id: &InstrumentId) -> Option<&OwnOrderBook> {
        self.own_books.get(instrument_id)
    }

    /// Gets a reference to the own order book for the `instrument_id`.
    #[must_use]
    pub fn own_order_book_mut(
        &mut self,
        instrument_id: &InstrumentId,
    ) -> Option<&mut OwnOrderBook> {
        self.own_books.get_mut(instrument_id)
    }

    /// Gets a reference to the latest quote for the `instrument_id`.
    #[must_use]
    pub fn quote(&self, instrument_id: &InstrumentId) -> Option<&QuoteTick> {
        self.quotes
            .get(instrument_id)
            .and_then(|quotes| quotes.front())
    }

    /// Gets a reference to the latest trade for the `instrument_id`.
    #[must_use]
    pub fn trade(&self, instrument_id: &InstrumentId) -> Option<&TradeTick> {
        self.trades
            .get(instrument_id)
            .and_then(|trades| trades.front())
    }

    /// Gets a reference to the latest mark price update for the `instrument_id`.
    #[must_use]
    pub fn mark_price(&self, instrument_id: &InstrumentId) -> Option<&MarkPriceUpdate> {
        self.mark_prices
            .get(instrument_id)
            .and_then(|mark_prices| mark_prices.front())
    }

    /// Gets a reference to the latest index price update for the `instrument_id`.
    #[must_use]
    pub fn index_price(&self, instrument_id: &InstrumentId) -> Option<&IndexPriceUpdate> {
        self.index_prices
            .get(instrument_id)
            .and_then(|index_prices| index_prices.front())
    }

    /// Gets a reference to the latest funding rate update for the `instrument_id`.
    #[must_use]
    pub fn funding_rate(&self, instrument_id: &InstrumentId) -> Option<&FundingRateUpdate> {
        self.funding_rates
            .get(instrument_id)
            .and_then(|funding_rates| funding_rates.front())
    }

    /// Gets a reference to the latest bar for the `bar_type`.
    #[must_use]
    pub fn bar(&self, bar_type: &BarType) -> Option<&Bar> {
        self.bars.get(bar_type).and_then(|bars| bars.front())
    }

    /// Gets the order book update count for the `instrument_id`.
    #[must_use]
    pub fn book_update_count(&self, instrument_id: &InstrumentId) -> usize {
        self.books
            .get(instrument_id)
            .map_or(0, |book| book.update_count) as usize
    }

    /// Gets the quote tick count for the `instrument_id`.
    #[must_use]
    pub fn quote_count(&self, instrument_id: &InstrumentId) -> usize {
        self.quotes
            .get(instrument_id)
            .map_or(0, std::collections::VecDeque::len)
    }

    /// Gets the trade tick count for the `instrument_id`.
    #[must_use]
    pub fn trade_count(&self, instrument_id: &InstrumentId) -> usize {
        self.trades
            .get(instrument_id)
            .map_or(0, std::collections::VecDeque::len)
    }

    /// Gets the bar count for the `instrument_id`.
    #[must_use]
    pub fn bar_count(&self, bar_type: &BarType) -> usize {
        self.bars
            .get(bar_type)
            .map_or(0, std::collections::VecDeque::len)
    }

    /// Returns whether the cache contains an order book for the `instrument_id`.
    #[must_use]
    pub fn has_order_book(&self, instrument_id: &InstrumentId) -> bool {
        self.books.contains_key(instrument_id)
    }

    /// Returns whether the cache contains quotes for the `instrument_id`.
    #[must_use]
    pub fn has_quote_ticks(&self, instrument_id: &InstrumentId) -> bool {
        self.quote_count(instrument_id) > 0
    }

    /// Returns whether the cache contains trades for the `instrument_id`.
    #[must_use]
    pub fn has_trade_ticks(&self, instrument_id: &InstrumentId) -> bool {
        self.trade_count(instrument_id) > 0
    }

    /// Returns whether the cache contains bars for the `bar_type`.
    #[must_use]
    pub fn has_bars(&self, bar_type: &BarType) -> bool {
        self.bar_count(bar_type) > 0
    }

    #[must_use]
    pub fn get_xrate(
        &self,
        venue: Venue,
        from_currency: Currency,
        to_currency: Currency,
        price_type: PriceType,
    ) -> Option<f64> {
        if from_currency == to_currency {
            // When the source and target currencies are identical,
            // no conversion is needed; return an exchange rate of 1.0.
            return Some(1.0);
        }

        let (bid_quote, ask_quote) = self.build_quote_table(&venue);

        match get_exchange_rate(
            from_currency.code,
            to_currency.code,
            price_type,
            bid_quote,
            ask_quote,
        ) {
            Ok(rate) => rate,
            Err(e) => {
                log::error!("Failed to calculate xrate: {e}");
                None
            }
        }
    }

    fn build_quote_table(&self, venue: &Venue) -> (AHashMap<String, f64>, AHashMap<String, f64>) {
        let mut bid_quotes = AHashMap::new();
        let mut ask_quotes = AHashMap::new();

        for instrument_id in self.instruments.keys() {
            if instrument_id.venue != *venue {
                continue;
            }

            let (bid_price, ask_price) = if let Some(ticks) = self.quotes.get(instrument_id) {
                if let Some(tick) = ticks.front() {
                    (tick.bid_price, tick.ask_price)
                } else {
                    continue; // Empty ticks vector
                }
            } else {
                let bid_bar = self
                    .bars
                    .iter()
                    .find(|(k, _)| {
                        k.instrument_id() == *instrument_id
                            && matches!(k.spec().price_type, PriceType::Bid)
                    })
                    .map(|(_, v)| v);

                let ask_bar = self
                    .bars
                    .iter()
                    .find(|(k, _)| {
                        k.instrument_id() == *instrument_id
                            && matches!(k.spec().price_type, PriceType::Ask)
                    })
                    .map(|(_, v)| v);

                match (bid_bar, ask_bar) {
                    (Some(bid), Some(ask)) => {
                        match (bid.front(), ask.front()) {
                            (Some(bid_bar), Some(ask_bar)) => (bid_bar.close, ask_bar.close),
                            _ => {
                                // Empty bar VecDeques
                                continue;
                            }
                        }
                    }
                    _ => continue,
                }
            };

            bid_quotes.insert(instrument_id.symbol.to_string(), bid_price.as_f64());
            ask_quotes.insert(instrument_id.symbol.to_string(), ask_price.as_f64());
        }

        (bid_quotes, ask_quotes)
    }

    /// Returns the mark exchange rate for the given currency pair, or `None` if not set.
    #[must_use]
    pub fn get_mark_xrate(&self, from_currency: Currency, to_currency: Currency) -> Option<f64> {
        self.mark_xrates.get(&(from_currency, to_currency)).copied()
    }

    /// Sets the mark exchange rate for the given currency pair and automatically sets the inverse rate.
    ///
    /// # Panics
    ///
    /// Panics if `xrate` is not positive.
    pub fn set_mark_xrate(&mut self, from_currency: Currency, to_currency: Currency, xrate: f64) {
        assert!(xrate > 0.0, "xrate was zero");
        self.mark_xrates.insert((from_currency, to_currency), xrate);
        self.mark_xrates
            .insert((to_currency, from_currency), 1.0 / xrate);
    }

    /// Clears the mark exchange rate for the given currency pair.
    pub fn clear_mark_xrate(&mut self, from_currency: Currency, to_currency: Currency) {
        let _ = self.mark_xrates.remove(&(from_currency, to_currency));
    }

    /// Clears all mark exchange rates.
    pub fn clear_mark_xrates(&mut self) {
        self.mark_xrates.clear();
    }

    // -- INSTRUMENT QUERIES ----------------------------------------------------------------------

    /// Returns a reference to the instrument for the `instrument_id` (if found).
    #[must_use]
    pub fn instrument(&self, instrument_id: &InstrumentId) -> Option<&InstrumentAny> {
        self.instruments.get(instrument_id)
    }

    /// Returns references to all instrument IDs for the `venue`.
    #[must_use]
    pub fn instrument_ids(&self, venue: Option<&Venue>) -> Vec<&InstrumentId> {
        match venue {
            Some(v) => self.instruments.keys().filter(|i| &i.venue == v).collect(),
            None => self.instruments.keys().collect(),
        }
    }

    /// Returns references to all instruments for the `venue`.
    #[must_use]
    pub fn instruments(&self, venue: &Venue, underlying: Option<&Ustr>) -> Vec<&InstrumentAny> {
        self.instruments
            .values()
            .filter(|i| &i.id().venue == venue)
            .filter(|i| underlying.is_none_or(|u| i.underlying() == Some(*u)))
            .collect()
    }

    /// Returns references to all bar types contained in the cache.
    #[must_use]
    pub fn bar_types(
        &self,
        instrument_id: Option<&InstrumentId>,
        price_type: Option<&PriceType>,
        aggregation_source: AggregationSource,
    ) -> Vec<&BarType> {
        let mut bar_types = self
            .bars
            .keys()
            .filter(|bar_type| bar_type.aggregation_source() == aggregation_source)
            .collect::<Vec<&BarType>>();

        if let Some(instrument_id) = instrument_id {
            bar_types.retain(|bar_type| bar_type.instrument_id() == *instrument_id);
        }

        if let Some(price_type) = price_type {
            bar_types.retain(|bar_type| &bar_type.spec().price_type == price_type);
        }

        bar_types
    }

    // -- SYNTHETIC QUERIES -----------------------------------------------------------------------

    /// Returns a reference to the synthetic instrument for the `instrument_id` (if found).
    #[must_use]
    pub fn synthetic(&self, instrument_id: &InstrumentId) -> Option<&SyntheticInstrument> {
        self.synthetics.get(instrument_id)
    }

    /// Returns references to instrument IDs for all synthetic instruments contained in the cache.
    #[must_use]
    pub fn synthetic_ids(&self) -> Vec<&InstrumentId> {
        self.synthetics.keys().collect()
    }

    /// Returns references to all synthetic instruments contained in the cache.
    #[must_use]
    pub fn synthetics(&self) -> Vec<&SyntheticInstrument> {
        self.synthetics.values().collect()
    }

    // -- ACCOUNT QUERIES -----------------------------------------------------------------------

    /// Returns a reference to the account for the `account_id` (if found).
    #[must_use]
    pub fn account(&self, account_id: &AccountId) -> Option<&AccountAny> {
        self.accounts.get(account_id)
    }

    /// Returns a reference to the account for the `venue` (if found).
    #[must_use]
    pub fn account_for_venue(&self, venue: &Venue) -> Option<&AccountAny> {
        self.index
            .venue_account
            .get(venue)
            .and_then(|account_id| self.accounts.get(account_id))
    }

    /// Returns a reference to the account ID for the `venue` (if found).
    #[must_use]
    pub fn account_id(&self, venue: &Venue) -> Option<&AccountId> {
        self.index.venue_account.get(venue)
    }

    /// Returns references to all accounts for the `account_id`.
    #[must_use]
    pub fn accounts(&self, account_id: &AccountId) -> Vec<&AccountAny> {
        self.accounts
            .values()
            .filter(|account| &account.id() == account_id)
            .collect()
    }

    /// Updates the own order book with an order.
    ///
    /// This method adds, updates, or removes an order from the own order book
    /// based on the order's current state.
    ///
    /// Orders without prices (MARKET, etc.) are skipped as they cannot be
    /// represented in own books.
    pub fn update_own_order_book(&mut self, order: &OrderAny) {
        if !order.has_price() {
            return;
        }

        let instrument_id = order.instrument_id();

        let own_book = self
            .own_books
            .entry(instrument_id)
            .or_insert_with(|| OwnOrderBook::new(instrument_id));

        let own_book_order = order.to_own_book_order();

        if order.is_closed() {
            if let Err(e) = own_book.delete(own_book_order) {
                log::debug!(
                    "Failed to delete order {} from own book: {e}",
                    order.client_order_id(),
                );
            } else {
                log::debug!("Deleted order {} from own book", order.client_order_id());
            }
        } else {
            // Add or update the order in the own book
            if let Err(e) = own_book.update(own_book_order) {
                log::debug!(
                    "Failed to update order {} in own book: {e}; inserting instead",
                    order.client_order_id(),
                );
                own_book.add(own_book_order);
            }
            log::debug!("Updated order {} in own book", order.client_order_id());
        }
    }

    /// Force removal of an order from own order books and clean up all indexes.
    ///
    /// This method is used when order event application fails and we need to ensure
    /// terminal orders are properly cleaned up from own books and all relevant indexes.
    /// Replicates the index cleanup that update_order performs for closed orders.
    pub fn force_remove_from_own_order_book(&mut self, client_order_id: &ClientOrderId) {
        let order = match self.orders.get(client_order_id) {
            Some(order) => order,
            None => return,
        };

        self.index.orders_open.remove(client_order_id);
        self.index.orders_pending_cancel.remove(client_order_id);
        self.index.orders_inflight.remove(client_order_id);
        self.index.orders_emulated.remove(client_order_id);

        if let Some(own_book) = self.own_books.get_mut(&order.instrument_id())
            && order.has_price()
        {
            let own_book_order = order.to_own_book_order();
            if let Err(e) = own_book.delete(own_book_order) {
                log::debug!("Could not force delete {client_order_id} from own book: {e}");
            } else {
                log::debug!("Force deleted {client_order_id} from own book");
            }
        }

        self.index.orders_closed.insert(*client_order_id);
    }

    /// Audit all own order books against open and inflight order indexes.
    ///
    /// Ensures closed orders are removed from own order books. This includes both
    /// orders tracked in `orders_open` (ACCEPTED, TRIGGERED, PENDING_*, PARTIALLY_FILLED)
    /// and `orders_inflight` (INITIALIZED, SUBMITTED) to prevent false positives
    /// during venue latency windows.
    pub fn audit_own_order_books(&mut self) {
        log::debug!("Starting own books audit");
        let start = std::time::Instant::now();

        // Build union of open and inflight orders for audit,
        // this prevents false positives for SUBMITTED orders during venue latency.
        let valid_order_ids: AHashSet<ClientOrderId> = self
            .index
            .orders_open
            .union(&self.index.orders_inflight)
            .copied()
            .collect();

        for own_book in self.own_books.values_mut() {
            own_book.audit_open_orders(&valid_order_ids);
        }

        log::debug!("Completed own books audit in {:?}", start.elapsed());
    }
}