#property indicator_separate_window

#property indicator_buffers 3

#property indicator_color1 White
#property indicator_color2 Red
#property indicator_color3 Blue

#define STRING_ID "MACD_DivergenceLine"

extern int Fast = 9;
extern int Slow = 21;
extern int Signal = 5;

extern int Depth = 1;
extern int ShowHidden = 0;

extern int DrawGraphics = 1;

double Value[];
double Sell[];
double Buy[];

int      Tops[];
int      Bottoms[];
double   Prices[];

string IndicatorName;
datetime LastTime;

int init()
{
   SetIndexBuffer(0, Value);

   SetIndexBuffer(1, Sell);
   SetIndexBuffer(2, Buy);
   
   SetIndexStyle(1, DRAW_HISTOGRAM);
   SetIndexStyle(2, DRAW_HISTOGRAM);

   IndicatorName = "Divergence(" + Fast + ", " + Slow + ", " + Signal + ")";
   IndicatorShortName(IndicatorName);
   
   LastTime = 0;
   
   ArrayResize(Tops, Depth + 1);
   ArrayResize(Bottoms, Depth + 1);
   ArrayResize(Prices, Depth + 1);

   return(0);
}

int deinit()
{
   for(int i = ObjectsTotal() - 1; i >= 0; i--)
   {
      string label = ObjectName(i);
      if(StringFind(label, STRING_ID) != -1)
      {
         ObjectDelete(label);
      }
   }
   
   return(0);
}

int start()
{
   if (LastTime == Time[0]) return (0);
   LastTime = Time[0];

   int toCount = Bars - IndicatorCounted();
   
   for(int i = toCount - 1; i >= 0; i--)
   {
      Value[i] = iMACD(NULL, 0, Fast, Slow, Signal, PRICE_CLOSE, 1, i);
   }
      
   for(i = toCount - 1; i >= 0; i--)
   {
      if (Sell[i + 2] != EMPTY_VALUE)
      {
         Sell[i + 1] = Value[i + 1];
      }

      if (Buy[i + 2] != EMPTY_VALUE)
      {
         Buy[i + 1] = Value[i + 1];
      }
      
      CatchBullishDivergence(i + 2);
      CatchBearishDivergence(i + 2);
   }              
   
   return(0);
}

void CatchBullishDivergence(int shift)
{
   if(!IsBottom(shift)) return;
   
   Sell[shift - 1] = EMPTY_VALUE;
   
   Bottoms[0] = shift;
   Prices[0] = Low[shift];
   
   for (int i = 1; i <= Depth; i++)
   {
      Bottoms[i] = GetLastBottom(Bottoms[i - 1]);
      Prices[i] = Low[Bottoms[i]];
   }
   
   bool gotSignal = false;
   
   for (i = 1; i <= Depth; i++)
   {
      if (Bottoms[i] == -1) return;
      if (Prices[i] == 0 || Prices[i] == EMPTY_VALUE) return;

      if(Value[Bottoms[0]] < Value[Bottoms[i]] && 
         Prices[0] > Prices[i])
      {
         gotSignal = true;
      }
      
      if(Value[Bottoms[0]] > Value[Bottoms[i]] && 
         Prices[0] < Prices[i] &&
         ShowHidden == 1)
      {
         gotSignal = true;
      }
      
      if (gotSignal)      
      {
         DrawPriceTrendLine(
               Time[Bottoms[0]], 
               Time[Bottoms[i]], 
               Prices[0],
               Prices[i],
               Blue, 
               STYLE_SOLID);
            
         DrawIndicatorTrendLine(
               Time[Bottoms[0]], 
               Time[Bottoms[i]], 
               Value[Bottoms[0]],
               Value[Bottoms[i]],
               Blue, 
               STYLE_SOLID);

         Buy[shift - 1] = Value[shift - 1];
         return;
      }
   }
}

void CatchBearishDivergence(int shift)
{
   if(!IsTop(shift)) return;
   
   Buy[shift - 1] = EMPTY_VALUE;
   
   Tops[0] = shift;
   Prices[0] = High[shift];
   
   for (int i = 1; i <= Depth; i++)
   {
      Tops[i] = GetLastTop(Tops[i - 1]);
      Prices[i] = High[Tops[i]];
   }
   
   bool gotSignal = false;
   
   for (i = 1; i <= Depth; i++)
   {
      if (Tops[i] == -1) return;
      if (Prices[i] == 0 || Tops[i] == EMPTY_VALUE) return;

      if(Value[Tops[0]] > Value[Tops[i]] && 
         Prices[0] < Prices[i])
      {
         gotSignal = true;
      }
      
      if(Value[Tops[0]] < Value[Tops[i]] && 
         Prices[0] > Prices[i] &&
         ShowHidden == 1)
      {
         gotSignal = true;
      }
      
      if (gotSignal)      
      {
         DrawPriceTrendLine(
               Time[Tops[0]], 
               Time[Tops[i]], 
               Prices[0],
               Prices[i],
               Red, 
               STYLE_SOLID);
            
         DrawIndicatorTrendLine(
               Time[Tops[0]], 
               Time[Tops[i]], 
               Value[Tops[0]],
               Value[Tops[i]],
               Red, 
               STYLE_SOLID);

         Sell[shift - 1] = Value[shift - 1];
         return;
      }
   }
}

bool IsTop(int i)
{
   return (
      Value[i - 1] != EMPTY_VALUE &&
      Value[i    ] != EMPTY_VALUE &&
      Value[i + 1] != EMPTY_VALUE &&
      Value[i + 1] < Value[i] && 
      Value[i - 1] < Value[i]);
}

bool IsBottom(int i)
{
   return (
      Value[i - 1] != EMPTY_VALUE &&
      Value[i    ] != EMPTY_VALUE &&
      Value[i + 1] != EMPTY_VALUE &&
      Value[i + 1] > Value[i] && 
      Value[i - 1] > Value[i]);
}

int GetLastTop(int shift)
{
   for(int i = shift + 1; i < Bars; i++)
   {
      if (IsTop(i)) return (i);
   }

   return(-1);
}

int GetLastBottom(int shift)
{
   for(int i = shift + 1; i < Bars; i++)
   {
      if (IsBottom(i)) return (i);
   }

   return(-1);
}

void DrawPriceTrendLine(datetime x1, datetime x2, double y1, 
                        double y2, color lineColor, double style)
{
   if (DrawGraphics == 0) return;
   string label = STRING_ID + "_Price" + DoubleToStr(x1, 0) + DoubleToStr(x2, 0);
   
   ObjectDelete(label);
   ObjectCreate(label, OBJ_TREND, 0, x1, y1, x2, y2, 0, 0);
   
   ObjectSet(label, OBJPROP_RAY, 0);
   ObjectSet(label, OBJPROP_COLOR, lineColor);
   ObjectSet(label, OBJPROP_STYLE, style);
   ObjectSet(label, OBJPROP_WIDTH, 2);
}

void DrawIndicatorTrendLine(datetime x1, datetime x2, double y1, 
                            double y2, color lineColor, double style)
{
   if (DrawGraphics == 0) return;
   int indicatorWindow = WindowFind(IndicatorName);
   if (indicatorWindow < 0) return;
   
   string label = STRING_ID + "_Value" + DoubleToStr(x1, 0) + DoubleToStr(x2, 0);
   
   ObjectDelete(label);
   ObjectCreate(label, OBJ_TREND, indicatorWindow, x1, y1, x2, y2, 0, 0);
   
   ObjectSet(label, OBJPROP_RAY, 0);
   ObjectSet(label, OBJPROP_COLOR, lineColor);
   ObjectSet(label, OBJPROP_STYLE, style);
   ObjectSet(label, OBJPROP_WIDTH, 2);
}