//+------------------------------------------------------------------+
//|                                                    Bollinger.mqh |
//|                                  Copyright 2021, MetaQuotes Ltd. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property copyright "Copyright 2021, MetaQuotes Ltd."
#property link      "https://www.mql5.com"
#property version   "1.00"

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
class CBollingerBands
  {
private:
   int               InitHandle(string symbol, ENUM_TIMEFRAMES period, int bbPeriod, int maShift, double bbDev, ENUM_APPLIED_PRICE appliedPrice, bool displayAtChart);
   int               bollingerRange;

public:
                     CBollingerBands();
                     CBollingerBands(string symbol, ENUM_TIMEFRAMES period, int bbPeriod, int maShift, double bbDeviation, ENUM_APPLIED_PRICE bollingerAppliedPrice, bool displayAtChart, int bbRange);
                    ~CBollingerBands();

   bool              BollingerOpenBuySignal(int openBuyCount, double Ask);
   bool              BollingerOpenSellSignal(int openSellCount, double Bid);
   bool              BollingerCloseBuySignal(int openBuyCount, double Ask);
   bool              BollingerCloseSellSignal(int openSellCount, double Bid);

   double            upBand[];
   double            downBand[];
   double            mediumBand[];
   
   int               handle;
   
   void              FillBuffer(int BBHandle);
  };
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
CBollingerBands::CBollingerBands()
  {
   this.handle = InitHandle(_Symbol, PERIOD_CURRENT, 30, 0, 1, PRICE_CLOSE, true);
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
CBollingerBands::CBollingerBands(string symbol, ENUM_TIMEFRAMES period, int bbPeriod, int maShift, double bbDeviation, ENUM_APPLIED_PRICE bollingerAppliedPrice, bool displayAtChart, int bbRange)
  {
   this.handle = InitHandle(symbol, period, bbPeriod, maShift, bbDeviation, bollingerAppliedPrice, displayAtChart);
   this.bollingerRange = bbRange;
  }
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
CBollingerBands::~CBollingerBands()
  {
  }
//+------------------------------------------------------------------+

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
bool CBollingerBands::BollingerOpenBuySignal(int openBuyCount, double Ask)
  {
   double diff_Bollinger = upBand[0] - downBand[0];   // Разница между верхним и нижним Bollinger
   if(openBuyCount == 0 && Ask <= downBand[0] && diff_Bollinger > bollingerRange * _Point)
      return true;
   return false;
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
bool CBollingerBands::BollingerOpenSellSignal(int openSellCount, double Bid)
  {
   double diff_Bollinger = upBand[0] - downBand[0];
   if(openSellCount == 0 && Bid >= upBand[0] && diff_Bollinger > bollingerRange * _Point)
      return true;
   return false;
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
bool CBollingerBands::BollingerCloseBuySignal(int openBuyCount, double Ask)
  {
   if(openBuyCount > 0 && Ask >= upBand[0])
      return true;
   return false;
  }

//+------------------------------------------------------------------+
bool CBollingerBands::BollingerCloseSellSignal(int openSellCount, double Bid)
  {
   if(openSellCount > 0 && Bid <= downBand[0])
      return true;
   return false;
  }
  
//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
int CBollingerBands::InitHandle(string symbol, ENUM_TIMEFRAMES period, int bbPeriod, int maShift, double bbDev, ENUM_APPLIED_PRICE appliedPrice, bool displayAtChart)
  {
  Print(displayAtChart);
   int BBHandle = iBands(symbol, period, bbPeriod, maShift, bbDev, appliedPrice);
   if(BBHandle < 0)
     {
      Print("Ошибка при создании BBHandle - № ошибки: ", _LastError, "!!");
      return -1;
     }
   if (displayAtChart) ChartIndicatorAdd(ChartID(), 0, BBHandle);
   return BBHandle;
  }

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void CBollingerBands:: FillBuffer(int bollingerHandle)
  {
   ArraySetAsSeries(upBand, true);
   ArraySetAsSeries(downBand, true);
   ArraySetAsSeries(mediumBand, true);
   
   ArrayResize(upBand, 5);
   ArrayResize(downBand, 5);
   ArrayResize(mediumBand, 5);

   int bbands_up = CopyBuffer(bollingerHandle, 1, 0, 5, upBand);
   int bbands_dn = CopyBuffer(bollingerHandle, 2, 0, 5, downBand);
   int bbands_bs = CopyBuffer(bollingerHandle, 0, 0, 5, mediumBand);

   if(bbands_bs < 0 || bbands_up < 0 || bbands_dn < 0)
     {
      Print("Данные Bollinger bands  не загрузились", _LastError);
      SendMail(_Symbol + "Ошибка загрузки данных индикатора Bollinger bands  ", _Symbol + " Ошибка загрузки данных индикаторов");
      return;
     }
  }