diff --git a/Include/MyIncludes/AD_Calculator.mqh b/Include/MyIncludes/AD_Calculator.mqh
new file mode 100644
index 0000000..0a13797
--- /dev/null
+++ b/Include/MyIncludes/AD_Calculator.mqh
@@ -0,0 +1,125 @@
+//+------------------------------------------------------------------+
+//|                                                AD_Calculator.mqh |
+//|         Calculation engine for Standard and Heikin Ashi A/D.     |
+//|                                        Copyright 2025, xxxxxxxx  |
+//+------------------------------------------------------------------+
+#property copyright "Copyright 2025, xxxxxxxx"
+
+#include <MyIncludes\HeikinAshi_Tools.mqh>
+
+//+==================================================================+
+//|                                                                  |
+//|             CLASS 1: CADCalculator (Base Class)                  |
+//|                                                                  |
+//+==================================================================+
+class CADCalculator
+  {
+protected:
+   //--- Internal buffers for the selected candle data
+   double            m_high[];
+   double            m_low[];
+   double            m_close[];
+
+   //--- Virtual method for preparing the candle data. Base class handles standard candles.
+   //--- CORRECTED: Added 'open' array to the signature for consistency with derived class.
+   virtual bool      PrepareCandleData(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[]);
+
+public:
+                     CADCalculator(void) {};
+   virtual          ~CADCalculator(void) {};
+
+   //--- Public calculation method
+   //--- CORRECTED: Added 'open' array to the signature.
+   void              Calculate(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[],
+                               const long &tick_volume[], const long &volume[], ENUM_APPLIED_VOLUME volume_type, double &ad_buffer[]);
+  };
+
+//+------------------------------------------------------------------+
+//| CADCalculator: Main Calculation Method (Shared Logic)            |
+//+------------------------------------------------------------------+
+void CADCalculator::Calculate(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[],
+                              const long &tick_volume[], const long &volume[], ENUM_APPLIED_VOLUME volume_type, double &ad_buffer[])
+  {
+   if(rates_total < 1)
+      return;
+
+//--- STEP 1: Prepare the source candle arrays (delegated to virtual method)
+   if(!PrepareCandleData(rates_total, open, high, low, close))
+      return;
+
+//--- STEP 2: Core A/D calculation using the prepared m_high[], m_low[], m_close[] arrays
+   for(int i = 0; i < rates_total; i++)
+     {
+      double mfm = 0; // Money Flow Multiplier
+      double range = m_high[i] - m_low[i];
+
+      if(range > 0)
+        {
+         mfm = ((m_close[i] - m_low[i]) - (m_high[i] - m_close[i])) / range;
+        }
+
+      long current_volume = (volume_type == VOLUME_TICK) ? tick_volume[i] : volume[i];
+      double mfv = mfm * current_volume; // Money Flow Volume
+
+      if(i > 0)
+         ad_buffer[i] = ad_buffer[i-1] + mfv;
+      else
+         ad_buffer[i] = mfv; // First value
+     }
+  }
+
+//+------------------------------------------------------------------+
+//| CADCalculator: Prepares the standard candle data series.         |
+//+------------------------------------------------------------------+
+bool CADCalculator::PrepareCandleData(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[])
+  {
+//--- CORRECTED: Use ArrayCopy for robust data handling instead of invalid pointer assignment.
+   ArrayResize(m_high, rates_total);
+   ArrayResize(m_low, rates_total);
+   ArrayResize(m_close, rates_total);
+
+   ArrayCopy(m_high, high, 0, 0, rates_total);
+   ArrayCopy(m_low, low, 0, 0, rates_total);
+   ArrayCopy(m_close, close, 0, 0, rates_total);
+
+   return true;
+  }
+
+//+==================================================================+
+//|                                                                  |
+//|             CLASS 2: CADCalculator_HA (Heikin Ashi)              |
+//|                                                                  |
+//+==================================================================+
+class CADCalculator_HA : public CADCalculator
+  {
+private:
+   CHeikinAshi_Calculator m_ha_calculator; // Instance of the HA calculator tool
+
+protected:
+   //--- Overridden method to prepare Heikin Ashi candle data
+   //--- CORRECTED: Signature now matches the base class, including 'open'.
+   virtual bool      PrepareCandleData(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[]) override;
+  };
+
+//+------------------------------------------------------------------+
+//| CADCalculator_HA: Prepares the Heikin Ashi candle data series.   |
+//+------------------------------------------------------------------+
+bool CADCalculator_HA::PrepareCandleData(int rates_total, const double &open[], const double &high[], const double &low[], const double &close[])
+  {
+//--- For the HA calculator, we must calculate and store the HA values.
+   ArrayResize(m_high, rates_total);
+   ArrayResize(m_low, rates_total);
+   ArrayResize(m_close, rates_total);
+
+//--- We need a temporary ha_open buffer for the calculation
+   double ha_open[];
+   ArrayResize(ha_open, rates_total);
+
+//--- Calculate the HA candles into our member arrays
+//--- CORRECTED: Removed invalid GetPointer() calls.
+   m_ha_calculator.Calculate(rates_total, open, high, low, close, ha_open, m_high, m_low, m_close);
+
+   return true;
+  }
+//+------------------------------------------------------------------+
+//+------------------------------------------------------------------+