S2-B3/S3-05: PortfolioRiskManager, connection loss recovery, long-only lock

src/NT8.Core/Risk/PortfolioRiskManager.cs

@@ -0,0 +1,265 @@
+// File: PortfolioRiskManager.cs
+using System;
+using System.Collections.Generic;
+using NT8.Core.Common.Models;
+using NT8.Core.Logging;
+
+namespace NT8.Core.Risk
+{
+    /// <summary>
+    /// Portfolio-level risk coordinator. Singleton. Enforces cross-strategy
+    /// daily loss limits, maximum open contract caps, and a portfolio kill switch.
+    /// Must be registered by each strategy on init and unregistered on terminate.
+    /// Thread-safe via a single lock object.
+    /// </summary>
+    public class PortfolioRiskManager
+    {
+        private static readonly object _instanceLock = new object();
+        private static PortfolioRiskManager _instance;
+
+        /// <summary>
+        /// Gets the singleton instance of PortfolioRiskManager.
+        /// </summary>
+        public static PortfolioRiskManager Instance
+        {
+            get
+            {
+                if (_instance == null)
+                {
+                    lock (_instanceLock)
+                    {
+                        if (_instance == null)
+                            _instance = new PortfolioRiskManager();
+                    }
+                }
+                return _instance;
+            }
+        }
+
+        private readonly object _lock = new object();
+        private readonly Dictionary<string, RiskConfig> _registeredStrategies;
+        private readonly Dictionary<string, double> _strategyPnL;
+        private readonly Dictionary<string, int> _strategyOpenContracts;
+
+        /// <summary>
+        /// Maximum combined daily loss across all registered strategies before all trading halts.
+        /// Default: 2000.0
+        /// </summary>
+        public double PortfolioDailyLossLimit { get; set; }
+
+        /// <summary>
+        /// Maximum total open contracts across all registered strategies simultaneously.
+        /// Default: 6
+        /// </summary>
+        public int MaxTotalOpenContracts { get; set; }
+
+        /// <summary>
+        /// When true, all new orders across all strategies are blocked immediately.
+        /// Set to true to perform an emergency halt of the entire portfolio.
+        /// </summary>
+        public bool PortfolioKillSwitch { get; set; }
+
+        private PortfolioRiskManager()
+        {
+            _registeredStrategies = new Dictionary<string, RiskConfig>();
+            _strategyPnL = new Dictionary<string, double>();
+            _strategyOpenContracts = new Dictionary<string, int>();
+            PortfolioDailyLossLimit = 2000.0;
+            MaxTotalOpenContracts = 6;
+            PortfolioKillSwitch = false;
+        }
+
+        /// <summary>
+        /// Registers a strategy with the portfolio manager. Called from
+        /// NT8StrategyBase.InitializeSdkComponents() during State.DataLoaded.
+        /// </summary>
+        /// <param name="strategyId">Unique strategy identifier (use Name from NT8StrategyBase).</param>
+        /// <param name="config">The strategy's risk configuration.</param>
+        /// <exception cref="ArgumentNullException">strategyId or config is null.</exception>
+        public void RegisterStrategy(string strategyId, RiskConfig config)
+        {
+            if (string.IsNullOrEmpty(strategyId)) throw new ArgumentNullException("strategyId");
+            if (config == null) throw new ArgumentNullException("config");
+
+            lock (_lock)
+            {
+                _registeredStrategies[strategyId] = config;
+                if (!_strategyPnL.ContainsKey(strategyId))
+                    _strategyPnL[strategyId] = 0.0;
+                if (!_strategyOpenContracts.ContainsKey(strategyId))
+                    _strategyOpenContracts[strategyId] = 0;
+            }
+        }
+
+        /// <summary>
+        /// Unregisters a strategy. Called from NT8StrategyBase during State.Terminated.
+        /// </summary>
+        /// <param name="strategyId">Strategy identifier to unregister.</param>
+        public void UnregisterStrategy(string strategyId)
+        {
+            if (string.IsNullOrEmpty(strategyId)) return;
+
+            lock (_lock)
+            {
+                _registeredStrategies.Remove(strategyId);
+                _strategyPnL.Remove(strategyId);
+                _strategyOpenContracts.Remove(strategyId);
+            }
+        }
+
+        /// <summary>
+        /// Validates a new order intent against portfolio-level risk limits.
+        /// Called before per-strategy risk validation in ProcessStrategyIntent().
+        /// </summary>
+        /// <param name="strategyId">The strategy requesting the order.</param>
+        /// <param name="intent">The trade intent to validate.</param>
+        /// <returns>RiskDecision indicating whether the order is allowed.</returns>
+        public RiskDecision ValidatePortfolioRisk(string strategyId, StrategyIntent intent)
+        {
+            if (string.IsNullOrEmpty(strategyId)) throw new ArgumentNullException("strategyId");
+            if (intent == null) throw new ArgumentNullException("intent");
+
+            lock (_lock)
+            {
+                // Kill switch — blocks everything immediately
+                if (PortfolioKillSwitch)
+                {
+                    var ksMetrics = new Dictionary<string, object>();
+                    ksMetrics.Add("kill_switch", true);
+                    return new RiskDecision(
+                        allow: false,
+                        rejectReason: "Portfolio kill switch is active — all trading halted",
+                        modifiedIntent: null,
+                        riskLevel: RiskLevel.Critical,
+                        riskMetrics: ksMetrics);
+                }
+
+                // Portfolio daily loss limit
+                double totalPnL = 0.0;
+                foreach (var kvp in _strategyPnL)
+                    totalPnL += kvp.Value;
+
+                if (totalPnL <= -PortfolioDailyLossLimit)
+                {
+                    var pnlMetrics = new Dictionary<string, object>();
+                    pnlMetrics.Add("portfolio_pnl", totalPnL);
+                    pnlMetrics.Add("limit", PortfolioDailyLossLimit);
+                    return new RiskDecision(
+                        allow: false,
+                        rejectReason: String.Format(
+                            "Portfolio daily loss limit breached: {0:C} <= -{1:C}",
+                            totalPnL, PortfolioDailyLossLimit),
+                        modifiedIntent: null,
+                        riskLevel: RiskLevel.Critical,
+                        riskMetrics: pnlMetrics);
+                }
+
+                // Total open contract cap
+                int totalContracts = 0;
+                foreach (var kvp in _strategyOpenContracts)
+                    totalContracts += kvp.Value;
+
+                if (totalContracts >= MaxTotalOpenContracts)
+                {
+                    var contractMetrics = new Dictionary<string, object>();
+                    contractMetrics.Add("total_contracts", totalContracts);
+                    contractMetrics.Add("limit", MaxTotalOpenContracts);
+                    return new RiskDecision(
+                        allow: false,
+                        rejectReason: String.Format(
+                            "Portfolio contract cap reached: {0} >= {1}",
+                            totalContracts, MaxTotalOpenContracts),
+                        modifiedIntent: null,
+                        riskLevel: RiskLevel.High,
+                        riskMetrics: contractMetrics);
+                }
+
+                // All portfolio checks passed
+                var okMetrics = new Dictionary<string, object>();
+                okMetrics.Add("portfolio_pnl", totalPnL);
+                okMetrics.Add("total_contracts", totalContracts);
+                return new RiskDecision(
+                    allow: true,
+                    rejectReason: null,
+                    modifiedIntent: null,
+                    riskLevel: RiskLevel.Low,
+                    riskMetrics: okMetrics);
+            }
+        }
+
+        /// <summary>
+        /// Reports a fill to the portfolio manager. Updates open contract count for the strategy.
+        /// Called from NT8StrategyBase.OnExecutionUpdate() after each fill.
+        /// </summary>
+        /// <param name="strategyId">Strategy that received the fill.</param>
+        /// <param name="fill">Fill details.</param>
+        public void ReportFill(string strategyId, OrderFill fill)
+        {
+            if (string.IsNullOrEmpty(strategyId) || fill == null) return;
+
+            lock (_lock)
+            {
+                if (!_strategyOpenContracts.ContainsKey(strategyId))
+                    _strategyOpenContracts[strategyId] = 0;
+
+                _strategyOpenContracts[strategyId] += fill.Quantity;
+                if (_strategyOpenContracts[strategyId] < 0)
+                    _strategyOpenContracts[strategyId] = 0;
+            }
+        }
+
+        /// <summary>
+        /// Reports a P&L update for a strategy. Called from NT8StrategyBase
+        /// whenever the strategy's realized P&L changes (typically on position close).
+        /// </summary>
+        /// <param name="strategyId">Strategy reporting P&L.</param>
+        /// <param name="pnl">Current cumulative day P&L for this strategy.</param>
+        public void ReportPnL(string strategyId, double pnl)
+        {
+            if (string.IsNullOrEmpty(strategyId)) return;
+
+            lock (_lock)
+            {
+                _strategyPnL[strategyId] = pnl;
+            }
+        }
+
+        /// <summary>
+        /// Resets daily P&L accumulators for all strategies. Does not clear registrations
+        /// or open contract counts. Typically called at the start of a new trading day.
+        /// </summary>
+        public void ResetDaily()
+        {
+            lock (_lock)
+            {
+                var keys = new List<string>(_strategyPnL.Keys);
+                foreach (var key in keys)
+                    _strategyPnL[key] = 0.0;
+            }
+        }
+
+        /// <summary>
+        /// Returns a snapshot of current portfolio state for diagnostics.
+        /// </summary>
+        public string GetStatusSnapshot()
+        {
+            lock (_lock)
+            {
+                double totalPnL = 0.0;
+                foreach (var kvp in _strategyPnL)
+                    totalPnL += kvp.Value;
+
+                int totalContracts = 0;
+                foreach (var kvp in _strategyOpenContracts)
+                    totalContracts += kvp.Value;
+
+                return String.Format(
+                    "Portfolio: strategies={0} totalPnL={1:C} totalContracts={2} killSwitch={3}",
+                    _registeredStrategies.Count,
+                    totalPnL,
+                    totalContracts,
+                    PortfolioKillSwitch);
+            }
+        }
+    }
+}