Chaikin Money Flow in MQL

Dabbling with MQL, here is my take on Chaikin Money Flow, adapted from Forex Indicators. Happy for suggestions/ any pointers if you think this is incorrect.

#property copyright "Copyright 2019, Saveen Kumar"
#property copyright "Copyright 2019, Saveen Kumar"
#property link      "https://www.linkedin.com/in/saveenkumar/"
#property version   "1.00"
#property strict

//indicator properties
#property indicator_separate_window
#property indicator_buffers     1
#property indicator_color1      Magenta
#property indicator_level1      0
#property indicator_levelstyle  STYLE_DOT
#property indicator_levelcolor  Black

//indicator inputs
extern int    CMFPeriod = 20; //period for CMF

//buffers
double CMFLineBuffer[]; //for line, value of actual CMF

//+---------------------------------------------------+
//| Custom indicator initialization function          |
//+---------------------------------------------------+
int OnInit()
  {
   //--- check if  CMF period is acceptable
   if(CMFPeriod<2)
    {
     Print("CMF period needs to be more than 2");
      return(INIT_FAILED);
    }
  
   //set up the buffer
    IndicatorBuffers(indicator_buffers); 
    SetIndexStyle(0, DRAW_LINE); 
    SetIndexBuffer(0, CMFLineBuffer);     
   
    //show labels if wanted
    SetIndexLabel(0, "CMF"); 
    IndicatorShortName("CMF (" + 
              IntegerToString(CMFPeriod) +")");
          
    //begin drawing
    SetIndexDrawBegin(0,CMFPeriod);
   
    return(INIT_SUCCEEDED);
  }
//+-------------------------------------------------+
//| Custom indicator iteration function             |
//+-------------------------------------------------+
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
  {         
         //need minimum bars
         if(rates_total<=CMFPeriod) return(0);
                       
         //the number of bars to calculate in 
         //this iteration
         int limit=0;
      
         //if bars calculated are less than the
         //CMF period, buffer value up to the
         //period will be zero and we begin our
         //calculation of CMF after these
         //initial zero bars
         if(prev_calculated <= CMFPeriod)
         {
            for(int i=1;i<=CMFPeriod;i++) 
            {
               CMFLineBuffer[rates_total-i]=0.0;
            }
            limit=rates_total-CMFPeriod;        
         }
         //if more than CMF period bars already 
         //calculated, start after them  
         else{
            limit=rates_total-prev_calculated;
         }
        
         //main loop, where we are calculating  
         //only as many bars as are absolutely 
         //necessary        
         for(int i=0;i<=limit;i++)
         {
            double ADSum = 0.0;
            double VolSum = 0.0;
            
            for(int j=0;j0)
                  ADSum += tick_volume[i+j]*
                            (close[i+j]-open[j+i])/
                            (high[i+j]-low[i+j]);  
            }
            CMFLineBuffer[i]= ADSum/VolSum;
         }
         
      return(rates_total);   
     
      
  }