-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=67459

--+------------------------------------------------------------------+
--|                               Copyright © 2019, Gehtsoft USA LLC | 
--|                                            http://fxcodebase.com |
--+------------------------------------------------------------------+
--|                                      Developed by : Mario Jemic  |                    
--|                                          mario.jemic@gmail.com   |
--+------------------------------------------------------------------+
--|                                 Support our efforts by donating  | 
--|                                    Paypal: https://goo.gl/9Rj74e |
--+------------------------------------------------------------------+
--|                                Patreon :  https://goo.gl/GdXWeN  |  
--|                    BitCoin : 15VCJTLaz12Amr7adHSBtL9v8XomURo9RF  |  
--|                BitCoin Cash: 1BEtS465S3Su438Kc58h2sqvVvHK9Mijtg  | 
--|           Ethereum : 0x8C110cD61538fb6d7A2B47858F0c0AaBd663068D  |  
--|                   LiteCoin : LLU8PSY2vsq7B9kRELLZQcKf5nJQrdeqwD  |  
--+------------------------------------------------------------------+

-- Indicator profile initialization routine
-- Defines indicator profile properties and indicator parameters
-- TODO: Add minimal and maximal value of numeric parameters and default color of the streams
function Init()
    indicator:name("On Chart Bollinger Band Difference");
    indicator:description("");
    indicator:requiredSource(core.Bar);
    indicator:type(core.Indicator);

    indicator.parameters:addGroup("Calculation"); 
    indicator.parameters:addInteger("Period", "Period", "", 20, 1, 2000);
	indicator.parameters:addDouble("Deviation", "Deviation", "", 2, 0, 100);
	
	
	indicator.parameters:addGroup("Placement");
	indicator.parameters:addString("Y", " Y Placement","" , "Top");
    indicator.parameters:addStringAlternative("Y", "Top", "Top" , "Top");
    indicator.parameters:addStringAlternative("Y", "Bottom", "Bottom" , "Bottom"); 
	
	indicator.parameters:addString("X", " X Placement","" , "Left");
    indicator.parameters:addStringAlternative("X", "Right", "Right" , "Right");
    indicator.parameters:addStringAlternative("X", "Left", "Left" , "Left"); 
    indicator.parameters:addInteger("ShiftY", "Shift","" , 0);
 
	
	indicator.parameters:addGroup("Style");
   indicator.parameters:addColor("Label", "Label Color", "", core.rgb(0, 0, 0)); 
   indicator.parameters:addInteger("Size", "Font Size", "", 20);
    indicator.parameters:addColor("color", "Line Color", "", core.rgb(255, 0, 0));
 
end

-- Indicator instance initialization routine
-- Processes indicator parameters and creates output streams
-- TODO: Refine the first period calculation for each of the output streams.
-- TODO: Calculate all constants, create instances all subsequent indicators and load all required libraries
-- Parameters block

local first;
local source = nil;
local X,Y;
local font;
local Label;
local Size;
local ShiftY;



local Period;
local Deviation; 
  
local BB;
-- Routine
 function Prepare(nameOnly)  


    Period= instance.parameters.Period;
	Deviation= instance.parameters.Deviation;
	
 
     local Parameters= Period ..  ", " .. Deviation;
 
    local name = profile:id() .. "(" ..  instance.source:name() ..  ", " ..  Parameters .. ")";
    instance:name(name); 


    if   (nameOnly) then
        return;
    end

    Y=instance.parameters.Y;
	X=instance.parameters.X;  
	ShiftY=instance.parameters.ShiftY;
    Label=instance.parameters.Label;
	Size=instance.parameters.Size;   
    source = instance.source;
    
	BB = core.indicators:create("BB", source, Period, Deviation);    
    first=BB.DATA:first();

	
	
 
    instance:ownerDrawn(true);
	
	
	
	
end

-- Indicator calculation routine
-- TODO: Add your code for calculation output values
 
function Update(period,mode)   

  
   BB:update(mode);
   
   
end
 
local init = false;
 
function Draw(stage, context)
      
	  local period= source:size()-1;
	  
 
	  if stage~= 2 
	  or BB== nil
	  or not BB.DATA:hasData(period)
	  then
	  return;
	  end
	
        if not init then
           context:createFont (1, "Arial", context:pointsToPixels (Size), context:pointsToPixels (Size), 0);
            init = true;
        end
		
		
	
	
	local 	TLBL=(BB.TL[period]-BB.BL[period])/source:pipSize();
	local   TLAL=(BB.TL[period]-BB.AL[period])/source:pipSize();
	
			
	local Text1=  "Top/Bottom : " ..   win32.formatNumber(TLBL, false, source:getPrecision());
	 
   local i=1;	 
   width, height = context:measureText (1, Text1, 0);
   context:drawText (1,  Text1, Label, -1,  iX(context,width,0,1) ,  iY(context,height,i,0) ,iX(context,width,0,2),iY(context,height,i,1), 0 );	
   
   
   local Text2=  "Top/Central : " ..   win32.formatNumber(TLAL, false, source:getPrecision());
	 
   local i=2;	 
   width, height = context:measureText (1, Text2, 0);
   context:drawText (1,  Text2, Label, -1,  iX(context,width,0,1) ,  iY(context,height,i,0) ,iX(context,width,0,2),iY(context,height,i,1), 0 );	
   
end		
 
 

function iX(context, width,Shift,x)

	if X== "Left" then
	return  context:left()+ Shift*width +  width*(x-1) ;
	else
	return context:right() - width*Shift -  width*(1-(x-1));
	end
end



function iY(context, height,Index , Line)

	if Y== "Top" then
		return context:top()+Index*height +ShiftY*height + Line *height;
	else
		if Line== 1 then
		return context:bottom()-(Index+1)*height -ShiftY*height + height;
		else
		return context:bottom()-(Index+1)*height -ShiftY*height;
		end
	end
end