//description : This mql4 script will send email and make alert on ema crossover
//+------------------------------------------------------------------+
//|                                           MA-Crossover_Alert.mq4 |
//|         Copyright © 2005, Jason Robinson (jnrtrading)            |
//|                   http://www.jnrtading.co.uk                     |
//| Modified by Robert Hill to add LSMA and alert or send email      |
//| Added Global LastAlert to try to have alert only on new cross    |
//| but does not seem to work. So indicator does alert every bar     |
//+------------------------------------------------------------------+

/*
  +------------------------------------------------------------------+
  | Allows you to enter two ma periods and it will then show you at  |
  | Which point they crossed over. It is more usful on the shorter   |
  | periods that get obscured by the bars / candlesticks and when    |
  | the zoom level is out. Also allows you then to remove the  mas   |
  | from the chart. (emas are initially set at 5 and 6)              |
  +------------------------------------------------------------------+
*/   
#property copyright "Copyright © 2005, Jason Robinson (jnrtrading)"
#property link      "http://www.jnrtrading.co.uk"

#property indicator_chart_window
#property indicator_buffers 2
#property indicator_color1 LawnGreen
#property indicator_width1 2
#property indicator_color2 Red
#property indicator_width2 2

extern bool SoundON=true;
extern bool EmailON=false;

extern int FastMA_Mode = 1; //0=sma, 1=ema, 2=smma, 3=lwma, 4=lsma
extern int FastMA_Period =   5;
extern int FastPriceMode = 0;//0=close, 1=open, 2=high, 3=low, 4=median(high+low)/2, 5=typical(high+low+close)/3, 6=weighted(high+low+close+close)/4
extern int SlowMA_Mode = 1; //0=sma, 1=ema, 2=smma, 3=lwma, 4=lsma
extern int SlowMA_Period =   6;
extern int SlowPriceMode = 0;//0=close, 1=open, 2=high, 3=low, 4=median(high+low)/2, 5=typical(high+low+close)/3, 6=weighted(high+low+close+close)/4
double CrossUp[];
double CrossDown[];
int flagval1 = 0;
int flagval2 = 0;

//int    weights[]; // Array uses by TMA
//double divisor;   // Used by TMA

//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
 
//---- indicators
//   IndicatorBuffers(3);
   SetIndexStyle(0, DRAW_ARROW, EMPTY);
   SetIndexArrow(0, 233);
   SetIndexBuffer(0, CrossUp);
   SetIndexStyle(1, DRAW_ARROW, EMPTY);
   SetIndexArrow(1, 234);
   SetIndexBuffer(1, CrossDown);
//----

   return(0);
  }
//+------------------------------------------------------------------+
//| Custom indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
//---- 

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

//+------------------------------------------------------------------+
//| LSMA with PriceMode                                              |
//| PrMode  0=close, 1=open, 2=high, 3=low, 4=median(high+low)/2,    |
//| 5=typical(high+low+close)/3, 6=weighted(high+low+close+close)/4  |
//+------------------------------------------------------------------+

double LSMA(int Rperiod, int prMode, int shift)
{
   int i;
   double sum, pr;
   int length;
   double lengthvar;
   double tmp;
   double wt;

   length = Rperiod;
 
   sum = 0;
   for(i = length; i >= 1  ; i--)
   {
     lengthvar = length + 1;
     lengthvar /= 3;
     tmp = 0;
     switch (prMode)
     {
     case 0: pr = Close[length-i+shift];break;
     case 1: pr = Open[length-i+shift];break;
     case 2: pr = High[length-i+shift];break;
     case 3: pr = Low[length-i+shift];break;
     case 4: pr = (High[length-i+shift] + Low[length-i+shift])/2;break;
     case 5: pr = (High[length-i+shift] + Low[length-i+shift] + Close[length-i+shift])/3;break;
     case 6: pr = (High[length-i+shift] + Low[length-i+shift] + Close[length-i+shift] + Close[length-i+shift])/4;break;
     }
     tmp = ( i - lengthvar)*pr;
     sum+=tmp;
    }
    wt = sum*6/(length*(length+1));
    
    return(wt);
}

/*//====================================================================
// TMA coded as function from indicator code to save time on backtest
//====================================================================
double TMA(int Periods,int AppliedPrice,int shift)
{

  int i,j;
  double dPeriods = Periods;
  int to=MathCeil(dPeriods/2.0);
  
  //Calculate weigths
  ArrayResize(weights,Periods);

  for(i=0; i<to; i++)
  {
    weights[i]            = i+1;
    weights[Periods-1-i]  = i+1;
  }

  divisor = 0.0;
  
  for(j=0; j<Periods; j++)
    divisor += weights[j];
    
  double tma_val = 0.0;
  for(j=0; j<Periods; j++)
  {
      double price = getPrice(AppliedPrice, Periods-j);
      tma_val += price*weights[j];
  }

  return( tma_val/divisor);
}

//===================
// Used by TMA
//===================
double getPrice(int priceType, int index)
{
  double price = 0.0;
  
  switch(priceType)
  {
    case PRICE_OPEN    : price = Open[index];
                         break;
  
    case PRICE_HIGH    : price = High[index];
                         break;
  
    case PRICE_LOW     : price = Low[index];
                         break;
  
    case PRICE_MEDIAN  : price = (High[index]+Low[index])/2.0;
                         break;
  
    case PRICE_TYPICAL : price = (High[index]+Low[index]+Close[index])/3.0;
                         break;

    case PRICE_WEIGHTED: price = (High[index]+Low[index]+2*Close[index])/4.0;
                         break;

    
    case PRICE_CLOSE   : 
    default            : price = Close[index];
                         break;

  }
  
  return(price);
}
*/

//+------------------------------------------------------------------+
//| Custom indicator iteration function                              |
//+------------------------------------------------------------------+
int start() {
   int limit, i, counter;
   double tmp=0;
   double fastMAnow, slowMAnow, fastMAprevious, slowMAprevious;
   double Range, AvgRange;
   int counted_bars=IndicatorCounted();
//---- check for possible errors
   if(counted_bars<0) return(-1);
//---- last counted bar will be recounted
   if(counted_bars>0) counted_bars--;

   limit=Bars-counted_bars;
   
   for(i = 0; i <= limit; i++) {
   
      counter=i;
      Range=0;
      AvgRange=0;
      for (counter=i ;counter<=i+9;counter++)
      {
         AvgRange=AvgRange+MathAbs(High[counter]-Low[counter]);
      }
      Range=AvgRange/10;
       
      switch(FastMA_Mode)
      {
        case 4 :
        {
         fastMAnow = LSMA(FastMA_Period, FastPriceMode, i);
         fastMAprevious = LSMA(FastMA_Period, FastPriceMode,  i+1);
         break;
        }
        case 5 :
        {
   fastMAnow = iCustom(Symbol(),0,"TMA",FastMA_Period,0,i);
   fastMAprevious = iCustom(Symbol(),0,"TMA",FastMA_Period,0,i+1);
//         fastMAnow = TMA(FastMA_Period, FastPriceMode, i);
//         fastMAprevious = TMA(FastMA_Period, FastPriceMode, i+1);
         break;
        }
      
        default :
        {
         fastMAnow = iMA(NULL, 0, FastMA_Period, 0, FastMA_Mode, FastPriceMode, i);
         fastMAprevious = iMA(NULL, 0, FastMA_Period, 0, FastMA_Mode, FastPriceMode, i+1);
        }
      }

      switch(SlowMA_Mode)
      {
        case 4 :
        {
         slowMAnow = LSMA( SlowMA_Period, SlowPriceMode, i);
         slowMAprevious = LSMA( SlowMA_Period, SlowPriceMode, i+1);
        }
        case 5 :
        {
   slowMAnow = iCustom(Symbol(),0,"TMA",SlowMA_Period,0,i);
   slowMAprevious = iCustom(Symbol(),0,"TMA",SlowMA_Period,0,i+1);
//         slowMAnow = TMA(SlowMA_Period, SlowPriceMode, i);
//         slowMAprevious = TMA(SlowMA_Period, SlowPriceMode, i+1);
         break;
        }
        
        default :
        {
         slowMAnow = iMA(NULL, 0, SlowMA_Period, 0, SlowMA_Mode, SlowPriceMode, i);
         slowMAprevious = iMA(NULL, 0, SlowMA_Period, 0, SlowMA_Mode, SlowPriceMode, i+1);
        }
      }
      
      if ((fastMAnow > slowMAnow) && (fastMAprevious < slowMAprevious))
      {
         if (i == 1 && flagval1==0)
         {
           flagval1=1;
           flagval2=0;
           if (SoundON) Alert("BUY signal at Ask=",Ask,"\n Bid=",Bid,"\n Time=",TimeToStr(CurTime(),TIME_DATE)," ",TimeHour(CurTime()),":",TimeMinute(CurTime()),"\n Symbol=",Symbol()," Period=",Period());
           if (EmailON) SendMail("BUY signal alert","BUY signal at Ask="+DoubleToStr(Ask,4)+", Bid="+DoubleToStr(Bid,4)+", Date="+TimeToStr(CurTime(),TIME_DATE)+" "+TimeHour(CurTime())+":"+TimeMinute(CurTime())+" Symbol="+Symbol()+" Period="+Period());
         }
         CrossUp[i] = Low[i] - Range*0.75;
      }
      else if ((fastMAnow < slowMAnow) && (fastMAprevious > slowMAprevious))
      {
         if (i == 1 && flagval2==0)
         {
           flagval2=1;
           flagval1=0;
           if (SoundON) Alert("SELL signal at Ask=",Ask,"\n Bid=",Bid,"\n Date=",TimeToStr(CurTime(),TIME_DATE)," ",TimeHour(CurTime()),":",TimeMinute(CurTime()),"\n Symbol=",Symbol()," Period=",Period());
           if (EmailON) SendMail("SELL signal alert","SELL signal at Ask="+DoubleToStr(Ask,4)+", Bid="+DoubleToStr(Bid,4)+", Date="+TimeToStr(CurTime(),TIME_DATE)+" "+TimeHour(CurTime())+":"+TimeMinute(CurTime())+" Symbol="+Symbol()+" Period="+Period());
         }
         CrossDown[i] = High[i] + Range*0.75;
      }
   }

   return(0);
}