Refactor: Per-strategy isolated balance and PnL

lib/paper/engine.js

@@ -2,54 +2,92 @@ import { db } from '../db.js';
 import { notify } from '../notify.js';
 
 /**
- * Paper Trading Engine.
+ * Per-Strategy Paper Trading Engine.
- * Executes virtual trades, tracks PnL, stores in SurrealDB.
+ * Each strategy gets its own isolated balance, PnL, and trade history.
  */
-export class PaperEngine {
+class StrategyPaperAccount {
-  constructor(initialBalance = 1000) {
+  constructor(strategyName, initialBalance = 1000) {
+    this.strategyName = strategyName;
     this.balance = initialBalance;
+    this.initialBalance = initialBalance;
     this.openPositions = new Map(); // ticker -> [positions]
-    this.tradeHistory = [];
     this.totalPnL = 0;
     this.wins = 0;
     this.losses = 0;
   }
 
+  getStats() {
+    const openPositionsList = [];
+    for (const [, positions] of this.openPositions) {
+      openPositionsList.push(...positions);
+    }
+    return {
+      strategy: this.strategyName,
+      balance: parseFloat(this.balance.toFixed(2)),
+      initialBalance: this.initialBalance,
+      totalPnL: parseFloat(this.totalPnL.toFixed(2)),
+      wins: this.wins,
+      losses: this.losses,
+      winRate: this.wins + this.losses > 0
+        ? parseFloat(((this.wins / (this.wins + this.losses)) * 100).toFixed(1))
+        : 0,
+      openPositions: openPositionsList,
+      totalTrades: this.wins + this.losses
+    };
+  }
+}
+
+export class PaperEngine {
+  constructor(initialBalancePerStrategy = 1000) {
+    this.initialBalancePerStrategy = initialBalancePerStrategy;
+    this.accounts = new Map(); // strategyName -> StrategyPaperAccount
+  }
+
+  _getAccount(strategyName) {
+    if (!this.accounts.has(strategyName)) {
+      this.accounts.set(strategyName, new StrategyPaperAccount(strategyName, this.initialBalancePerStrategy));
+    }
+    return this.accounts.get(strategyName);
+  }
+
   async init() {
-    // Load state from SurrealDB
     try {
-      const state = await db.query('SELECT * FROM paper_state ORDER BY timestamp DESC LIMIT 1');
+      // Load saved per-strategy states
-      const saved = state[0]?.[0];
+      const states = await db.query('SELECT * FROM paper_strategy_state ORDER BY timestamp DESC');
-      if (saved) {
+      const rows = states[0] || [];
-        this.balance = saved.balance;
+      const seen = new Set();
-        this.totalPnL = saved.totalPnL;
+      for (const saved of rows) {
-        this.wins = saved.wins;
+        if (!saved.strategyName || seen.has(saved.strategyName)) continue;
-        this.losses = saved.losses;
+        seen.add(saved.strategyName);
-        console.log(`[Paper] Restored state: $${this.balance.toFixed(2)} balance, ${this.wins}W/${this.losses}L`);
+        const acct = this._getAccount(saved.strategyName);
+        acct.balance = saved.balance;
+        acct.totalPnL = saved.totalPnL;
+        acct.wins = saved.wins;
+        acct.losses = saved.losses;
+        console.log(`[Paper:${saved.strategyName}] Restored: $${acct.balance.toFixed(2)}, ${acct.wins}W/${acct.losses}L`);
       }
 
       // Load open positions
       const positions = await db.query('SELECT * FROM paper_positions WHERE settled = false');
       if (positions[0]) {
         for (const pos of positions[0]) {
-          const list = this.openPositions.get(pos.ticker) || [];
+          const acct = this._getAccount(pos.strategy);
+          const list = acct.openPositions.get(pos.ticker) || [];
           list.push(pos);
-          this.openPositions.set(pos.ticker, list);
+          acct.openPositions.set(pos.ticker, list);
         }
-        console.log(`[Paper] Restored ${this.openPositions.size} open position(s)`);
       }
     } catch (e) {
       console.error('[Paper] Init error (fresh start):', e.message);
     }
   }
 
-  /**
-   * Execute a paper trade from a strategy signal.
-   */
   async executeTrade(signal, marketState) {
-    const cost = signal.size; // Each contract costs signal.price cents, but we simplify: $1 per contract unit
+    const acct = this._getAccount(signal.strategy);
-    if (this.balance < cost) {
+    const cost = signal.size;
-      console.log(`[Paper] Insufficient balance ($${this.balance.toFixed(2)}) for $${cost} trade`);
+
+    if (acct.balance < cost) {
+      console.log(`[Paper:${signal.strategy}] Insufficient balance ($${acct.balance.toFixed(2)}) for $${cost} trade`);
       return null;
     }
 
@@ -58,7 +96,7 @@ export class PaperEngine {
       strategy: signal.strategy,
       ticker: signal.ticker,
       side: signal.side,
-      price: signal.price, // Entry price in cents
+      price: signal.price,
       size: signal.size,
       cost,
       reason: signal.reason,
@@ -74,40 +112,37 @@ export class PaperEngine {
       }
     };
 
-    this.balance -= cost;
+    acct.balance -= cost;
 
-    const list = this.openPositions.get(trade.ticker) || [];
+    const list = acct.openPositions.get(trade.ticker) || [];
     list.push(trade);
-    this.openPositions.set(trade.ticker, list);
+    acct.openPositions.set(trade.ticker, list);
 
-    // Store in SurrealDB
     try {
       await db.create('paper_positions', trade);
-      await this._saveState();
+      await this._saveState(acct);
     } catch (e) {
       console.error('[Paper] DB write error:', e.message);
     }
 
-    const msg = `📝 PAPER ${trade.side.toUpperCase()} @ ${trade.price}¢ ($${cost}) | ${trade.strategy} | ${trade.reason}`;
+    const msg = `📝 PAPER [${trade.strategy}] ${trade.side.toUpperCase()} @ ${trade.price}¢ ($${cost}) | ${trade.reason}`;
     console.log(`[Paper] ${msg}`);
-    await notify(msg, 'Paper Trade');
+    await notify(msg, `Paper: ${trade.strategy}`);
 
     return trade;
   }
 
-  /**
-   * Settle all positions for a ticker when the market resolves.
-   */
   async settle(ticker, result) {
-    const positions = this.openPositions.get(ticker);
+    const allSettled = [];
-    if (!positions || positions.length === 0) return;
 
-    console.log(`[Paper] Settling ${positions.length} position(s) for ${ticker}, result: ${result}`);
+    for (const [strategyName, acct] of this.accounts) {
+      const positions = acct.openPositions.get(ticker);
+      if (!positions || positions.length === 0) continue;
+
+      console.log(`[Paper:${strategyName}] Settling ${positions.length} position(s) for ${ticker}, result: ${result}`);
 
       for (const pos of positions) {
         const won = pos.side === result;
-      // Payout: if won, pay out at $1 per contract (100¢), minus cost
-      // If lost, lose the cost
         const payout = won ? (100 / pos.price) * pos.cost : 0;
         const pnl = payout - pos.cost;
 
@@ -116,62 +151,87 @@ export class PaperEngine {
         pos.pnl = parseFloat(pnl.toFixed(2));
         pos.settleTime = Date.now();
 
-      this.balance += payout;
+        acct.balance += payout;
-      this.totalPnL += pnl;
+        acct.totalPnL += pnl;
 
-      if (won) this.wins++;
+        if (won) acct.wins++;
-      else this.losses++;
+        else acct.losses++;
 
-      // Update in SurrealDB
         try {
-        await db.query(`UPDATE paper_positions SET settled = true, result = $result, pnl = $pnl, settleTime = $settleTime WHERE id = $id`, {
+          await db.query(
-          id: pos.id,
+            `UPDATE paper_positions SET settled = true, result = $result, pnl = $pnl, settleTime = $settleTime WHERE id = $id`,
-          result,
+            { id: pos.id, result, pnl: pos.pnl, settleTime: pos.settleTime }
-          pnl: pos.pnl,
+          );
-          settleTime: pos.settleTime
-        });
         } catch (e) {
           console.error('[Paper] Settle DB error:', e.message);
         }
 
         const emoji = won ? '✅' : '❌';
-      const msg = `${emoji} ${pos.strategy} ${pos.side.toUpperCase()} ${won ? 'WON' : 'LOST'} | PnL: $${pnl.toFixed(2)} | Balance: $${this.balance.toFixed(2)}`;
+        const msg = `${emoji} [${strategyName}] ${pos.side.toUpperCase()} ${won ? 'WON' : 'LOST'} | PnL: $${pnl.toFixed(2)} | Bal: $${acct.balance.toFixed(2)}`;
         console.log(`[Paper] ${msg}`);
-      await notify(msg, won ? 'Paper Win!' : 'Paper Loss');
+        await notify(msg, won ? `${strategyName} Win!` : `${strategyName} Loss`);
+
+        allSettled.push(pos);
       }
 
-    this.openPositions.delete(ticker);
+      acct.openPositions.delete(ticker);
-    await this._saveState();
+      await this._saveState(acct);
-
-    return positions;
     }
 
+    return allSettled.length > 0 ? allSettled : null;
+  }
+
+  /**
+   * Get combined stats (backward compat) — aggregates all strategies.
+   */
   getStats() {
-    const openPositionsList = [];
+    const allOpen = [];
-    for (const [ticker, positions] of this.openPositions) {
+    let totalBalance = 0;
-      openPositionsList.push(...positions);
+    let totalPnL = 0;
+    let totalWins = 0;
+    let totalLosses = 0;
+
+    for (const [, acct] of this.accounts) {
+      const s = acct.getStats();
+      totalBalance += s.balance;
+      totalPnL += s.totalPnL;
+      totalWins += s.wins;
+      totalLosses += s.losses;
+      allOpen.push(...s.openPositions);
     }
 
     return {
-      balance: parseFloat(this.balance.toFixed(2)),
+      balance: parseFloat(totalBalance.toFixed(2)),
-      totalPnL: parseFloat(this.totalPnL.toFixed(2)),
+      totalPnL: parseFloat(totalPnL.toFixed(2)),
-      wins: this.wins,
+      wins: totalWins,
-      losses: this.losses,
+      losses: totalLosses,
-      winRate: this.wins + this.losses > 0
+      winRate: totalWins + totalLosses > 0
-        ? parseFloat(((this.wins / (this.wins + this.losses)) * 100).toFixed(1))
+        ? parseFloat(((totalWins / (totalWins + totalLosses)) * 100).toFixed(1))
         : 0,
-      openPositions: openPositionsList,
+      openPositions: allOpen,
-      totalTrades: this.wins + this.losses
+      totalTrades: totalWins + totalLosses
     };
   }
 
-  async _saveState() {
+  /**
+   * Get per-strategy stats for the paper dashboard.
+   */
+  getPerStrategyStats() {
+    const result = {};
+    for (const [name, acct] of this.accounts) {
+      result[name] = acct.getStats();
+    }
+    return result;
+  }
+
+  async _saveState(acct) {
     try {
-      await db.create('paper_state', {
+      await db.create('paper_strategy_state', {
-        balance: this.balance,
+        strategyName: acct.strategyName,
-        totalPnL: this.totalPnL,
+        balance: acct.balance,
-        wins: this.wins,
+        totalPnL: acct.totalPnL,
-        losses: this.losses,
+        wins: acct.wins,
+        losses: acct.losses,
         timestamp: Date.now()
       });
     } catch (e) {