//+------------------------------------------------------------------+
//|                                                          RSI.mq4 |
//|                      Copyright © 2004, MetaQuotes Software Corp. |
//|                                       http://www.metaquotes.net/ |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2004, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net/"

#property indicator_separate_window
#property indicator_minimum 0
#property indicator_maximum 100
#property indicator_buffers 1
#property indicator_color1 DodgerBlue
//#property indicator_level1 30.0
//#property indicator_level2 70.0
//#property indicator_level3 50.0

//---- input parameters
extern int RSIPeriod=14;
extern int TL_bars=2;  // 1 or 2
//---- buffers
double RSIBuffer[];
double PosBuffer[];
double NegBuffer[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
string short_name;

int init()
  {
//---- 2 additional buffers are used for counting.
   IndicatorBuffers(3);
   SetIndexBuffer(1,PosBuffer);
   SetIndexBuffer(2,NegBuffer);
//---- indicator line
   SetIndexStyle(0,DRAW_LINE);
   SetIndexBuffer(0,RSIBuffer);
//---- name for DataWindow and indicator subwindow label
   short_name="RSI-TL"+DoubleToStr(TL_bars,0)+"("+RSIPeriod+")";
   IndicatorShortName(short_name);
   SetIndexLabel(0,short_name);
//----
   SetIndexDrawBegin(0,RSIPeriod);
//----
   return(0);
  }

int deinit()
{
   ObjectDelete("RSI-TL_S"+DoubleToStr(TL_bars,0));
   ObjectDelete("RSI-TL_R"+DoubleToStr(TL_bars,0));
}
//+------------------------------------------------------------------+
//| Relative Strength Index                                          |
//+------------------------------------------------------------------+
int start()
  {
   int    i,counted_bars=IndicatorCounted();
   double rel,negative,positive;
//----
   if(Bars<=RSIPeriod) return(0);
//---- initial zero
   if(counted_bars<1)
      for(i=1;i<=RSIPeriod;i++) RSIBuffer[Bars-i]=0.0;
//----
   i=Bars-RSIPeriod-1;
   if(counted_bars>=RSIPeriod) i=Bars-counted_bars-1;
   while(i>=0)
     {
      double sumn=0.0,sump=0.0;
      if(i==Bars-RSIPeriod-1)
        {
         int k=Bars-2;
         //---- initial accumulation
         while(k>=i)
           {
            rel=Close[k]-Close[k+1];
            if(rel>0) sump+=rel;
            else      sumn-=rel;
            k--;
           }
         positive=sump/RSIPeriod;
         negative=sumn/RSIPeriod;
        }
      else
        {
         //---- smoothed moving average
         rel=Close[i]-Close[i+1];
         if(rel>0) sump=rel;
         else      sumn=-rel;
         positive=(PosBuffer[i+1]*(RSIPeriod-1)+sump)/RSIPeriod;
         negative=(NegBuffer[i+1]*(RSIPeriod-1)+sumn)/RSIPeriod;
        }
      PosBuffer[i]=positive;
      NegBuffer[i]=negative;
      if(negative==0.0) RSIBuffer[i]=0.0;
      else RSIBuffer[i]=100.0-100.0/(1+positive/negative);
      i--;
     }
//----

   int h1=0, h2=0, l1=0, l2=0;

   for(i=TL_bars+1;i<Bars;i++)
   {
      if (h1==0)
      {
         if (TL_bars==1)
         {
            if ((RSIBuffer[i-1]<RSIBuffer[i]) && (RSIBuffer[i+1]<RSIBuffer[i])) { h1=i; }
         }
         if (TL_bars==2)
         {
            if ( (RSIBuffer[i-1]<RSIBuffer[i]) && (RSIBuffer[i+1]<RSIBuffer[i]) && (RSIBuffer[i-2]<RSIBuffer[i]) && (RSIBuffer[i+2]<RSIBuffer[i]) ) { h1=i; }
         }
      }
      if ((h1>0) && (h2==0))
      {
         if (TL_bars==1)
         {
            if ( (RSIBuffer[i-1]<RSIBuffer[i]) && (RSIBuffer[i+1]<RSIBuffer[i]) && (RSIBuffer[i]>RSIBuffer[h1]) ) { h2=i; }
         }
         if (TL_bars==2)
         {
            if ( (RSIBuffer[i-1]<RSIBuffer[i]) && (RSIBuffer[i+1]<RSIBuffer[i]) && (RSIBuffer[i-2]<RSIBuffer[i]) && (RSIBuffer[i+2]<RSIBuffer[i]) && (RSIBuffer[i]>RSIBuffer[h1]) ) { h2=i; }
         }
      }
      if (l1==0)
      {
         if (TL_bars==1)
         {
            if ( (RSIBuffer[i-1]>RSIBuffer[i]) && (RSIBuffer[i+1]>RSIBuffer[i]) ) { l1=i; }
         }
         if (TL_bars==2)
         {
            if ( (RSIBuffer[i-1]>RSIBuffer[i]) && (RSIBuffer[i+1]>RSIBuffer[i]) && (RSIBuffer[i-2]>RSIBuffer[i]) && (RSIBuffer[i+2]>RSIBuffer[i]) ) { l1=i; }
         }
      }
      if ((l1>0) && (l2==0))
      {
         if (TL_bars==1)
         {
            if ( (RSIBuffer[i-1]>RSIBuffer[i]) && (RSIBuffer[i+1]>RSIBuffer[i]) && (RSIBuffer[i]<RSIBuffer[l1]) ) { l2=i; }
         }
         if (TL_bars==2)
         {
            if ( (RSIBuffer[i-1]>RSIBuffer[i]) && (RSIBuffer[i+1]>RSIBuffer[i]) && (RSIBuffer[i-2]>RSIBuffer[i]) && (RSIBuffer[i+2]>RSIBuffer[i]) && (RSIBuffer[i]<RSIBuffer[l1]) ) { l2=i; }
         }
      }
      if ((h1>0) && (h2>0) && (l1>0) && (l2>0)) { break; }
   }

   if ((h1>0) && (h2>0))
   {
      DrawIndicatorTrendLine(Time[h2], Time[h1], RSIBuffer[h2], RSIBuffer[h1], Red, short_name, "RSI"+DoubleToStr(RSIPeriod,0)+"-TL_R"+DoubleToStr(TL_bars,0));
   }
   if ((l1>0) && (l2>0))
   {
      DrawIndicatorTrendLine(Time[l2], Time[l1], RSIBuffer[l2], RSIBuffer[l1], Blue, short_name, "RSI"+DoubleToStr(RSIPeriod,0)+"-TL_S"+DoubleToStr(TL_bars,0));
   }

   return(0);
  }
//+------------------------------------------------------------------+

void DrawIndicatorTrendLine(datetime x1, datetime x2, double y1, double y2, color lineColor, string IndicatorName, string label)
{
   int indicatorWindow = WindowFind(IndicatorName);
   if (indicatorWindow < 0) return;

   ObjectDelete(label);
   ObjectCreate(label, OBJ_TREND, indicatorWindow, x1, y1, x2, y2, 0, 0);

   ObjectSet(label, OBJPROP_RAY, true);
   ObjectSet(label, OBJPROP_COLOR, lineColor);
   ObjectSet(label, OBJPROP_STYLE, STYLE_SOLID);
   ObjectSet(label, OBJPROP_WIDTH, 1);
}