fix: Implement session-scoped gate

NANDR_ORB_OB_EA.mq5

@@ -5,7 +5,7 @@
 //|  Based on: ORB-All-Sessions.pine + LuxAlgo Order Block Detector  |
 //+------------------------------------------------------------------+
 #property copyright "NANDR"
-#property version   "1.393"
+#property version   "1.394"
 #property strict
 
 #include <Trade\Trade.mqh>
@@ -1009,13 +1009,101 @@ int CountPendingOrders()
 }
 
 //+------------------------------------------------------------------+
-//| Single-active-entry policy                                       |
+//| Session-scoped active exposure                                   |
 //+------------------------------------------------------------------+
 bool HasActiveExposure()
 {
    return (CountOpenPositions() + CountPendingOrders()) > 0;
 }
 
+bool CommentHasSessionTag(const string comment, const string sessionName)
+{
+   if(comment == "" || sessionName == "")
+      return false;
+   return (StringFind(comment, "|" + sessionName + "|") >= 0);
+}
+
+string ResolveSessionNameForUtcTime(datetime utcTime)
+{
+   MqlDateTime t;
+   TimeToStruct(utcTime, t);
+   int nowMin = t.hour * 60 + t.min;
+
+   int bestIdx = -1;
+   int bestStart = -1;
+   for(int s = 0; s < g_SessionCount; s++)
+   {
+      if(!g_Sessions[s].enabled)
+         continue;
+
+      int startMin = g_Sessions[s].startHour * 60 + g_Sessions[s].startMin;
+      if(startMin <= nowMin && startMin >= bestStart)
+      {
+         bestStart = startMin;
+         bestIdx = s;
+      }
+   }
+
+   if(bestIdx >= 0)
+      return g_Sessions[bestIdx].name;
+
+   for(int s = 0; s < g_SessionCount; s++)
+   {
+      if(g_Sessions[s].enabled)
+         return g_Sessions[s].name;
+   }
+
+   return "";
+}
+
+int CountOpenPositionsForSession(const string sessionName)
+{
+   int count = 0;
+   for(int i = PositionsTotal() - 1; i >= 0; i--)
+   {
+      if(g_Position.SelectByIndex(i))
+      {
+         if(g_Position.Magic() == InpMagicNumber && g_Position.Symbol() == g_Symbol)
+         {
+            string comment = PositionGetString(POSITION_COMMENT);
+            if(CommentHasSessionTag(comment, sessionName))
+               count++;
+         }
+      }
+   }
+   return count;
+}
+
+int CountPendingOrdersForSession(const string sessionName)
+{
+   int count = 0;
+   for(int i = OrdersTotal() - 1; i >= 0; i--)
+   {
+      if(g_Order.SelectByIndex(i))
+      {
+         if(g_Order.Magic() == InpMagicNumber && g_Order.Symbol() == g_Symbol)
+         {
+            string comment = OrderGetString(ORDER_COMMENT);
+            if(CommentHasSessionTag(comment, sessionName))
+               count++;
+         }
+      }
+   }
+   return count;
+}
+
+bool HasActiveExposureForSession(const string sessionName)
+{
+   return (CountOpenPositionsForSession(sessionName) + CountPendingOrdersForSession(sessionName)) > 0;
+}
+
+bool HasActiveExposureForSession(int sessIdx)
+{
+   if(sessIdx < 0 || sessIdx >= g_SessionCount)
+      return false;
+   return HasActiveExposureForSession(g_Sessions[sessIdx].name);
+}
+
 double SessionMid(const SSession &sess)
 {
    return (sess.orbHigh + sess.orbLow) / 2.0;
@@ -1046,13 +1134,9 @@ void ResetLadderDirection(int sessIdx, int dir)
 
 void RefreshBreakoutEntryLocks()
 {
-   // Allow a new entry from the same breakout leg only after all managed
-   // positions/pending orders are gone (one ACTIVE entry at any time).
-   if(HasActiveExposure()) return;
-
    for(int s = 0; s < g_SessionCount; s++)
    {
-      if(g_Sessions[s].inBreakout)
+      if(g_Sessions[s].inBreakout && !HasActiveExposureForSession(s))
          g_Sessions[s].breakoutEntryTaken = false;
    }
 }
@@ -1061,7 +1145,7 @@ bool OpenLadderTrade(int sessIdx, int dir, double srcLevel, double dstLevel, con
 {
    if(g_TradingHalted) return false;
    if(g_TodayTrades >= InpMaxTradesPerDay) return false;
-   if(HasActiveExposure()) return false;
+   if(HasActiveExposureForSession(sessIdx)) return false;
    int ladderCap = GetEffectiveLadderCap(sessIdx);
    if(ladderCap > 0 && g_Sessions[sessIdx].ladderTradesThisSession >= ladderCap)
       return false;
@@ -1184,7 +1268,7 @@ bool TrySessionLadderEntry(int sessIdx,
    if(!IsLadderEnabledForSession(sessIdx)) return false;
    if(!g_Sessions[sessIdx].enabled || !g_Sessions[sessIdx].orbComplete) return false;
    if(!g_Sessions[sessIdx].inBreakout) return false;
-   if(HasActiveExposure()) return false;
+   if(HasActiveExposureForSession(sessIdx)) return false;
    if(g_Sessions[sessIdx].retestFiredThisBar) return false;
    if(InpBreakoutExpireBars > 0 && g_Sessions[sessIdx].breakoutBarsAgo >= InpBreakoutExpireBars) return false;
    int ladderCap = GetEffectiveLadderCap(sessIdx);
@@ -1278,7 +1362,7 @@ void OpenTrade(int dir, int sessIdx, double orbLevel, double obTop, double obBot
    if(g_TradingHalted) return;
    if(g_TodayTrades >= InpMaxTradesPerDay) return;
    if(g_Sessions[sessIdx].tradesThisSession >= InpMaxRetestsPerSession) return;
-   if(HasActiveExposure()) return;
+   if(HasActiveExposureForSession(sessIdx)) return;
    if(g_Sessions[sessIdx].breakoutEntryTaken) return;
 
    double ask = SymbolInfoDouble(g_Symbol, SYMBOL_ASK);
@@ -1318,7 +1402,7 @@ void OpenTrade(int dir, int sessIdx, double orbLevel, double obTop, double obBot
       // Do NOT clear inBreakout — the ORB level remains valid for subsequent retests
       // until the breakout expires, fails, or the daily reset. This allows the EA to
       // take multiple retest entries on the same level (e.g. 18:45 AND 20:45 retests).
-      // Re-entry is naturally gated by CountOpenPositions() checked at the top of OpenTrade.
+      // Re-entry is naturally gated by session-scoped exposure checks at the top of OpenTrade.
       PrintFormat("NANDR EA: Trade opened. Dir=%s Lots=%.2f Entry=%.2f SL=%.2f TP=%.2f Session=%s",
                   (dir > 0 ? "BUY" : "SELL"), lots, entry, sl, tp, g_Sessions[sessIdx].name);
       if(InpShowTradeLabels)
@@ -1351,6 +1435,7 @@ void CheckRetestEntriesTick()
    double ask   = SymbolInfoDouble(g_Symbol, SYMBOL_ASK);
    double bid   = SymbolInfoDouble(g_Symbol, SYMBOL_BID);
    double tol   = PipsToPrice(1.0);
+   string obSessionName = ResolveSessionNameForUtcTime(TimeCurrent() - g_ServerUtcOffsetSec);
 
    // ── ORB Session Retest Entries ──────────────────────────────────
    if(InpWaitForRetest)
@@ -1361,8 +1446,8 @@ void CheckRetestEntriesTick()
          if(!g_Sessions[s].enabled || !g_Sessions[s].orbComplete) continue;
          if(!g_Sessions[s].inBreakout) continue;
 
-         // --- Gate 2: no active exposure (one trade at a time) ---
+         // --- Gate 2: no active exposure for this session ---
-         if(HasActiveExposure()) continue;
+         if(HasActiveExposureForSession(s)) continue;
 
          // --- Gate 3: entry already taken and not yet released ---
          if(g_Sessions[s].breakoutEntryTaken) continue;
@@ -1417,7 +1502,7 @@ void CheckRetestEntriesTick()
    }
 
    // ── Session Level Ladder (fallback, only when no ORB entry taken this tick) ──
-   if(InpUseSessionLevelLadder && !HasActiveExposure())
+   if(InpUseSessionLevelLadder)
    {
       for(int s = 0; s < g_SessionCount; s++)
       {
@@ -1435,9 +1520,11 @@ void CheckRetestEntriesTick()
    for(int i = 0; i < g_BearOBCount; i++)
    {
       if(!g_BearOBs[i].active || g_BearOBs[i].traded) continue;
-      if(HasActiveExposure()) break;
       if(g_TodayTrades >= InpMaxTradesPerDay) break;
 
+      if(obSessionName == "") continue;
+      if(HasActiveExposureForSession(obSessionName)) continue;
+
       double obBottom = g_BearOBs[i].bottom;
       double obTop2   = g_BearOBs[i].top;
 
@@ -1453,7 +1540,7 @@ void CheckRetestEntriesTick()
       double lots   = CalcLotSize(slPips);
 
       bool result = g_Trade.Sell(lots, g_Symbol, 0, sl, tp,
-                                 StringFormat("NANDR|OBRetest|SELL|%.2f", obBottom));
+                                 StringFormat("NANDR|%s|OBRetest|SELL|%.2f", obSessionName, obBottom));
       if(result)
       {
          g_TodayTrades++;
@@ -1474,9 +1561,11 @@ void CheckRetestEntriesTick()
    for(int i = 0; i < g_BullOBCount; i++)
    {
       if(!g_BullOBs[i].active || g_BullOBs[i].traded) continue;
-      if(HasActiveExposure()) break;
       if(g_TodayTrades >= InpMaxTradesPerDay) break;
 
+      if(obSessionName == "") continue;
+      if(HasActiveExposureForSession(obSessionName)) continue;
+
       double obTop3    = g_BullOBs[i].top;
       double obBottom2 = g_BullOBs[i].bottom;
 
@@ -1492,7 +1581,7 @@ void CheckRetestEntriesTick()
       double lots   = CalcLotSize(slPips);
 
       bool result = g_Trade.Buy(lots, g_Symbol, 0, sl, tp,
-                                StringFormat("NANDR|OBRetest|BUY|%.2f", obTop3));
+                                StringFormat("NANDR|%s|OBRetest|BUY|%.2f", obSessionName, obTop3));
       if(result)
       {
          g_TodayTrades++;

README.md

@@ -24,6 +24,8 @@ A MetaTrader 5 Expert Advisor for scalping **XAUUSD (Gold/USD)** on **M15** (als
 
 Entry is taken when the ORB retest aligns with a nearby Order Block (optional — configurable).
 
+Active exposure is session-scoped: one open trade is allowed per session, and different sessions may each hold one trade on the same day.
+
 ### Session Level Ladder (New)
 - After a confirmed session breakout direction, the EA can trade between that session's ORB levels:
 - Bullish ladder: `Low -> Mid`, then `Mid -> High`