//+------------------------------------------------------------------+
//|                                                   MTBalancer.mqh |
//|                        Copyright 2018, MetaQuotes Software Corp. |
//|                                             https://www.mql5.com |
//+------------------------------------------------------------------+
#property version "1.3.2"
#include "MTUtils.mqh"

enum BalancerTrigger
  {
   mtb_position = 0,
   mtb_volume = 1
  };

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
class MTBalancer
  {
public:
   BalancerTrigger   balancer_type;
   int               positions_trigger;
   double            volume_difference;
   bool              enable_trade_on_limit;

protected:
   double            base_volume;
   double            balancing_volume;

public:
   void              setBaseVolume(double ibase_volume=0.1) {base_volume = ibase_volume;}
   void              setBalancingVolume(double balance) {balancing_volume = balance;};
   void              doBalancing(double ask,double bid,int take_profit);
   void              doBalancingByPositions(double ask,double bid,int take_profit);
   void              doBalancingByVolume(double ask,double bid,double take_profit);


  };

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void MTBalancer::doBalancing(double ask, double bid, int take_profit)
  {
//uint count_pos = PositionsTotal();
//if(count_pos == 0)
//  {
//   /*This is a safeguard for not "early stage" trading sessions */
//   return;
//  }

   switch(balancer_type)
     {
      case mtb_volume:
         if(GetVolumeDifference() >= volume_difference)
           {
            doBalancingByVolume(ask,bid,take_profit);
           }
         break;
      case mtb_position:
         if(PositionDifferenceByType() > positions_trigger)
           {
            doBalancingByPositions(ask,bid,take_profit);
           }
         break;
      default:
         break;

     }

  }

//+------------------------------------------------------------------+

//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void MTBalancer::doBalancingByVolume(double ask,double bid,double take_profit)
  {
   double top_edge = GetHigestPositionOpenPrice(); /*This needs to be check for error (-1)*/
   double bottom_edge = GetLowestPositionOpenPrice(); /*This needs to be check for error (-1)*/
   
   if(((ask >= top_edge) || (!enable_trade_on_limit)) && (GetVolumeDifference(true) < 0))
     {
      int current_difference = fabs(GetVolumeDifference()/base_volume);
      int unbalancer_value = fabs(balancing_volume/base_volume);
      place_a_long(ask, take_profit, current_difference + unbalancer_value);
     }


   if(((bid <= bottom_edge) || (!enable_trade_on_limit)) && (GetVolumeDifference(true) > 0))
     {
      int current_difference = fabs(GetVolumeDifference()/base_volume);
      int unbalancer_value = fabs(balancing_volume/base_volume);
      place_a_short(bid,take_profit, current_difference + unbalancer_value);
     }


  }


//+------------------------------------------------------------------+


//+------------------------------------------------------------------+
//|                                                                  |
//+------------------------------------------------------------------+
void MTBalancer::doBalancingByPositions(double ask,double bid,int take_profit)
  {
   double top_edge = GetHigestPositionOpenPrice();
   double bottom_edge = GetLowestPositionOpenPrice();
   int position_difference = PositionDifferenceByType(true);

   if((ask >= top_edge) && (position_difference>0))
     {
      place_a_long(ASK, take_profit);
     }
   else
      if((bid <= bottom_edge) && (position_difference < 0))
        {
         place_a_short(BID, take_profit);
        }
  }
//+------------------------------------------------------------------+