-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=63114


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function Init()
    indicator:name("Key Reversal");
    indicator:description("Key Reversal");
    indicator:requiredSource(core.Bar);
    indicator:type(core.Indicator);	   
 
	indicator.parameters:addBoolean("Trend", "Use Trend Filter", "", true);
	indicator.parameters:addInteger("Period", "Trend Period", "", 2);
    indicator.parameters:addInteger("Size", "Font Size", "", 10);
	indicator.parameters:addColor("Up", "Up Color", "", core.rgb(0, 255, 0));
    indicator.parameters:addColor("Down", "Down Color", "", core.rgb(255, 0, 0));
end

local ArrowSize;
local source;
local Up, Down;
local font, Size;
local Trend;
 function Prepare(nameOnly)   
    Up=instance.parameters.Up;
	Down=instance.parameters.Down;
	Size=instance.parameters.Size;
	Trend=instance.parameters.Trend;
	Period=instance.parameters.Period;
    local name =  profile:id() .. ","  .. instance.source:name() .. ","  .. Period;
	instance:name(name);	
	
	if   (nameOnly) then
        return;
    end
	
	font = core.host:execute("createFont", "Wingdings", Size, false, false);

	
    source = instance.source;
	first= source:first(); 	 
end

function ReleaseInstance()
       core.host:execute("deleteFont", font);
end
	   
 

function Update(period)
    
	core.host:execute ("removeLabel", source:serial(period))
	
    if    period  < first then
    return;
    end	
	
          if Verification(period) == 1 then
          core.host:execute("drawLabel1", source:serial(period), source:date(period), core.CR_CHART, source.low[period], core.CR_CHART, core.H_Center, core.V_Bottom, font, Up, "\225");
		  end
          if  Verification(period) == -1 then
          core.host:execute("drawLabel1", source:serial(period), source:date(period), core.CR_CHART, source.high[period], core.CR_CHART, core.H_Center, core.V_Top,font, Down, "\226");
          end  
		
end
 
function Verification(period)

 
  
  local Signal=0;
  if  source.close[period]> source.high[period-1]  then
  Signal=1;
  end
  
  if  source.close[period]< source.low[period-1]  then
  Signal=-1;
  end
   
  
  if not Trend then
  return Signal;
  end
  
  for i= 1, Period, 1 do
	  if Signal == 1
	  and source.close[period-i] > source.open[period-i] then
      Signal=0;
	  break;
	  end
	  
	  if Signal == -1
	  and source.close[period-i] < source.open[period-i] then
	  Signal=0;
	  break;
	  end
  end
  
  
  
  return Signal;
  
end