//+------------------------------------------------------------------+
//|                                                    C_Chapter2.mqh|
//+------------------------------------------------------------------+
#property copyright "Copyright 2025, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"

#include "AbstractChapter.mqh"
input int ba = 3;
class C_Chapter2 : public CAbstractChapter {

private:
   //========================
   // Bull state
   //========================
   int bosHigh, bosHigh0, noBosHigh;
   int bosHighbreakIndex, bosHighbreakIndex0;
   string protectedLowText;

   //========================
   // Bear state
   //========================
   int bosLow, bosLow0, noBosLow;
   int bosLowbreakIndex, bosLowbreakIndex0;
   string protectedHighText;

   //========================
   // Gates (independent engines)
   //========================
   int bullStartFrom;
   int bearStartFrom;
   
   int protectedHighIndex;
   int protectedLowIndex;
   //========================
   // Keys
   //========================
   string K_B_NoBosHigh() {
      return "CH2_B_NoBosHigh";
   }
   string K_B_BosHigh()   {
      return "CH2_B_BosHigh";
   }
   string K_B_BosHigh0()  {
      return "CH2_B_BosHigh0";
   }
   string K_B_ConfLow()   {
      return "CH2_B_ConfLow";
   }
   string K_B_ProtLow()   {
      return "CH2_B_ProtLow";
   }

   string K_S_NoBosLow()  {
      return "CH2_S_NoBosLow";
   }
   string K_S_BosLow()    {
      return "CH2_S_BosLow";
   }
   string K_S_BosLow0()   {
      return "CH2_S_BosLow0";
   }
   string K_S_ConfHigh()  {
      return "CH2_S_ConfHigh";
   }
   string K_S_ProtHigh()  {
      return "CH2_S_ProtHigh";
   }

   //========================
   // Draw
   //========================
   void DrawLine(string key, int fromIndex, int toIndex, double price, string text, color col = clrChartreuse, int style = 1) {
      if(fromIndex < 0 || toIndex < 0) return;
      if(fromIndex >= bar.Size() || toIndex >= bar.Size()) return;

      debug.LineWithCenteredText(
         key,
         bar.Time(fromIndex), price,
         bar.Time(toIndex),   price,
         text,
         style, col
      );
   }

   //========================
   // Breaks
   //========================
   bool BreakAbove(int refIndex, int barIndex) {
      return bar.Close(barIndex) > bar.High(refIndex);
   }
   bool BreakBelow(int refIndex, int barIndex) {
      return bar.Close(barIndex) < bar.Low(refIndex);
   }

   //========================
   // Extremes between points
   //========================
   int findLowest(int fromIndex, int toIndex) {
      int lowestIndex = -1;
      for(int i = fromIndex + 1; i < toIndex; i++) {
         if(lowestIndex == -1 || bar.Low(i) < bar.Low(lowestIndex))
            lowestIndex = i;
      }
      return lowestIndex;
   }

   int findHighest(int fromIndex, int toIndex) {
      int highestIndex = -1;
      for(int i = fromIndex + 1; i < toIndex; i++) {
         if(highestIndex == -1 || bar.High(i) > bar.High(highestIndex))
            highestIndex = i;
      }
      return highestIndex;
   }

   //========================
   // Find Nth previous VALID swing from an anchor (inclusive)
   // n=0 -> current if valid, n=1 -> 1 swing before, n=2 -> 2 swings before
   //========================
   int PrevSwingHighIndex(int anchor, int n) {
      int count = -1;
      for(int i = anchor; i >= 0; i--) {
         if(swing.IsValidValue(swing.HighAt(i))) {
            count++;
            if(count == n) return i;
          
         }
      }
      return -1;
   }

   int PrevSwingLowIndex(int anchor, int n) {
      int count = -1;
      for(int i = anchor; i >= 0; i--) {
         if(swing.IsValidValue(swing.LowAt(i))) {
            count++;
            if(count == n) return i;
         }
      }
      return -1;
   }

   //========================
   // Engines (pure updates, independent)
   //========================
   void UpdateBullFrom(int start) {
      for(int i = start; i < bar.Size() - 1; i++) {

         double up = swing.HighAt(i);

         if(swing.IsValidValue(up)) {
            if(bosHigh >= 0) {
               if(up > bar.High(bosHigh) && (noBosHigh < 0 || up > bar.High(noBosHigh)))
                  noBosHigh = i;
            } else {
               if(noBosHigh < 0 || up > bar.High(noBosHigh))
                  noBosHigh = i;
            }
         }

         if(noBosHigh != -1) {
            if(BreakAbove(noBosHigh, i) && swing.IsValidValue(swing.HighAt(noBosHigh))) {
               bosHigh0 = bosHigh;
               bosHighbreakIndex0 = bosHighbreakIndex;

               bosHigh = noBosHigh;
               bosHighbreakIndex = i;

               noBosHigh = i;
            }
         }

         if(noBosHigh >= 0 && !swing.IsValidValue(swing.HighAt(noBosHigh))) {
            if(bar.High(i) > bar.High(noBosHigh))
               noBosHigh = i;
         }
      }
   }

   void UpdateBearFrom(int start) {
      for(int i = start; i < bar.Size() - 1; i++) {

         double dn = swing.LowAt(i);

         if(swing.IsValidValue(dn)) {
            if(bosLow >= 0) {
               if(dn < bar.Low(bosLow) && (noBosLow < 0 || dn < bar.Low(noBosLow)))
                  noBosLow = i;
            } else {
               if(noBosLow < 0 || dn < bar.Low(noBosLow))
                  noBosLow = i;
            }
         }

         if(noBosLow != -1) {
            if(BreakBelow(noBosLow, i) && swing.IsValidValue(swing.LowAt(noBosLow))) {
               bosLow0 = bosLow;
               bosLowbreakIndex0 = bosLowbreakIndex;

               bosLow = noBosLow;
               bosLowbreakIndex = i;

               noBosLow = i;
            }
         }

         if(noBosLow >= 0 && !swing.IsValidValue(swing.LowAt(noBosLow))) {
            if(bar.Low(i) < bar.Low(noBosLow))
               noBosLow = i;
         }
      }
   }

   //========================
   // Pipelines (draw + detect reversal)
   //========================
   void confirmedLowChoch(int pNoBosHigh, int pBosHighBreak) {
      DrawLine(K_B_BosHigh(), pNoBosHigh, pBosHighBreak, bar.High(pNoBosHigh), "BOS", clrChartreuse, 1);

      int confirmedLow = findLowest(pNoBosHigh, pBosHighBreak);
      int breakBar = bar.Size() - 1;
      string text = "Confirmed Low";

      for(int i = confirmedLow; i < bar.Size() - 1; i++) {
         if(BreakBelow(confirmedLow, i)) {
            text = "CHOCH";
            protectedLowText = "Protected Low";
            breakBar = i;
            break;
         } else {
            protectedLowText = "Confirmed Low";
         }
      }

      DrawLine(K_B_ConfLow(), confirmedLow, breakBar, bar.Low(confirmedLow), text, clrChartreuse, 1);
   }

   // returns: START INDEX = 2 swings before the break (low side)
   int protectedLowBos(int pBosHigh, int pBosHighBreak) {

      DrawLine(K_B_BosHigh0(), pBosHigh, pBosHighBreak, bar.High(pBosHigh), "BOS", clrChartreuse, 1);

      int protectedLow = findLowest(pBosHigh, pBosHighBreak);
      int breakBar = bar.Size() - 1;
      string text = protectedLowText;

      for(int i = protectedLow; i < bar.Size() - 1; i++) {
         if(BreakBelow(protectedLow, i)) {
            text = "BOS REVERSAL";
            breakBar = i;
            break;
         }
      }
      protectedLowIndex=protectedLow;

      DrawLine(K_B_ProtLow(), protectedLow, breakBar, bar.Low(protectedLow), text, clrChartreuse, 1);

      if(text == "BOS REVERSAL") {
         // anchor at breakBar, take 2 swing lows before break
         return PrevSwingLowIndex(breakBar, ba);
      }

      return -1;
   }

   void confirmedHighChoch(int pNoBosLow, int pBosLowBreak) {
      DrawLine(K_S_BosLow(), pNoBosLow, pBosLowBreak, bar.Low(pNoBosLow), "BOS", clrTomato, 1);

      int confirmedHigh = findHighest(pNoBosLow, pBosLowBreak);
      int breakBar = bar.Size() - 1;
      string text = "Confirmed High";

      for(int i = confirmedHigh; i < bar.Size() - 1; i++) {
         if(BreakAbove(confirmedHigh, i)) {
            text = "CHOCH";
            protectedHighText = "Protected High";
            breakBar = i;
            break;
         } else {
            protectedHighText = "Confirmed High";
         }
      }

      DrawLine(K_S_ConfHigh(), confirmedHigh, breakBar, bar.High(confirmedHigh), text, clrTomato, 1);
   }

   // returns: START INDEX = 2 swings before the break (high side)
   int protectedHighBos(int pBosLow, int pBosLowBreak) {

      DrawLine(K_S_BosLow0(), pBosLow, pBosLowBreak, bar.Low(pBosLow), "BOS", clrTomato, 1);

      int protectedHigh = findHighest(pBosLow, pBosLowBreak);
      int breakBar = bar.Size() - 1;
      string text = protectedHighText;

      for(int i = protectedHigh; i < bar.Size() - 1; i++) {
         if(BreakAbove(protectedHigh, i)) {
            text = "BOS REVERSAL";
            breakBar = i;
            break;
         }
      }
     protectedHighIndex = protectedHigh;

      DrawLine(K_S_ProtHigh(), protectedHigh, breakBar, bar.High(protectedHigh), text, clrTomato, 1);

      if(text == "BOS REVERSAL") {
         // anchor at breakBar, take 2 swing highs before break
         return PrevSwingHighIndex(breakBar, ba);
      }

      return -1;
   }

   //========================
   // Relationship switches (start from 2 swings before break)
   //========================
   void SwitchToBearFromBull(int startSwingLow) {
      bearStartFrom = (startSwingLow >= 0 ? startSwingLow : bearStartFrom);

      bosLow = -1;
      bosLow0 = -1;
      bosLowbreakIndex = -1;
      bosLowbreakIndex0 = -1;
      protectedHighText = "";

      noBosLow = startSwingLow;
   }

   void SwitchToBullFromBear(int startSwingHigh) {
      bullStartFrom = (startSwingHigh >= 0 ? startSwingHigh : bullStartFrom);

      bosHigh = -1;
      bosHigh0 = -1;
      bosHighbreakIndex = -1;
      bosHighbreakIndex0 = -1;
      protectedLowText = "";

      noBosHigh = startSwingHigh;
   }

public:
   C_Chapter2();
   ~C_Chapter2();
   void OnCalculate();
   
     // >>> getters for Chapter 3 wiring
   int GetProtectedHighIndex() { return protectedHighIndex; }
   int GetProtectedLowIndex()  { return protectedLowIndex;  }


};

//+------------------------------------------------------------------+
C_Chapter2::C_Chapter2() {

   bosHigh = -1;
   bosHigh0 = -1;
   noBosHigh = -1;
   bosHighbreakIndex = -1;
   bosHighbreakIndex0 = -1;
   protectedLowText = "";

   bosLow = -1;
   bosLow0 = -1;
   noBosLow = -1;
   bosLowbreakIndex = -1;
   bosLowbreakIndex0 = -1;
   protectedHighText = "";

   bullStartFrom = 0;
   bearStartFrom = 0;
}

C_Chapter2::~C_Chapter2() {}

//+------------------------------------------------------------------+
void C_Chapter2::OnCalculate() {

   if(OnNewBar())
      return;

   bar.UpdateFromMonthsBack(symbol, timeframe, 3);

   // Update both engines every time (independent)
   UpdateBullFrom(bullStartFrom);
   UpdateBearFrom(bearStartFrom);

   // Draw CHOCH legs
   if(bosHigh >= 0 && bosHighbreakIndex >= 0)
      confirmedLowChoch(bosHigh, bosHighbreakIndex);

   if(bosLow >= 0 && bosLowbreakIndex >= 0)
      confirmedHighChoch(bosLow, bosLowbreakIndex);

   // Detect reversals: start opposite engine from 2 swings before break
   int startBearFromSwingLow = -1;
   int startBullFromSwingHigh = -1;

   if(bosHigh0 >= 0 && bosHighbreakIndex0 >= 0)
      startBearFromSwingLow = protectedLowBos(bosHigh0, bosHighbreakIndex0);

   if(bosLow0 >= 0 && bosLowbreakIndex0 >= 0)
      startBullFromSwingHigh = protectedHighBos(bosLow0, bosLowbreakIndex0);

   if(startBearFromSwingLow >= 0) {
      SwitchToBearFromBull(startBearFromSwingLow);
      UpdateBearFrom(bearStartFrom);
   }

   if(startBullFromSwingHigh >= 0) {
      SwitchToBullFromBear(startBullFromSwingHigh);
      UpdateBullFrom(bullStartFrom);
   }

   // NoBOS lines
   if(noBosHigh >= 0)
      DrawLine(K_B_NoBosHigh(), noBosHigh, bar.GetBarCount() - 1, bar.High(noBosHigh), "NO BOS", clrChartreuse, 1);

   if(noBosLow >= 0)
      DrawLine(K_S_NoBosLow(), noBosLow, bar.GetBarCount() - 1, bar.Low(noBosLow), "NO BOS", clrTomato, 1);
}
//+------------------------------------------------------------------+