-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=65141

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-- 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("Session change");
    indicator:description("");
    indicator:requiredSource(core.Bar);
    indicator:type(core.Indicator);

    indicator.parameters:addDouble("From", "Session Start Time", "Session Start Time", 0); 

    indicator.parameters:addString("Type", "Type", "", "Percent");
    indicator.parameters:addStringAlternative("Type", "Percent", "", "Percent");
    indicator.parameters:addStringAlternative("Type", "Pip", "", "Pip");	
	indicator.parameters:addStringAlternative("Type", "Both", "", "Both");	
	
	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","" , "Right");
    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("Up", "Up Label Color", "", core.rgb(0, 255, 0)); 
   indicator.parameters:addColor("Down", "Down Label Color", "", core.rgb(255, 0, 0)); 
   indicator.parameters:addInteger("Size", "Font Size", "", 20);
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 Change;
local first;
local source = nil;
local X,Y;
local font;
local Up,Down;
local Size;
local ShiftY;
local From;
local Type;
-- Routine
function Prepare(nameOnly)  
    Y=instance.parameters.Y;
	X=instance.parameters.X;  
	From=instance.parameters.From;
	ShiftY=instance.parameters.ShiftY;
    Up=instance.parameters.Up;
	Down=instance.parameters.Down;
	Size=instance.parameters.Size; 
    Type=instance.parameters.Type;	
    source = instance.source;
    first=source:first();
	
	
	if   (nameOnly) then
        return;
    end
	
    local name = profile:id() .. "(" .. source:name() .. ")";
    instance:name(name);
   	
    instance:ownerDrawn(true);
end




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

  
 
  
end
 
local init = false;
 
function Draw(stage, context)
 
	  if stage~= 2 
	  then
	  return;
	  end
	
        if not init then
           context:createFont (1, "Arial", context:pointsToPixels (Size), context:pointsToPixels (Size), 0);
            init = true;
        end
	
	local p= GetDate()

	if p==0 then
	return;
    end
 
   local Text1;
   
   if Type == "Percent" then
   Change= (source.close[source.close:size()-1]- source.close[p])/(source.close[p]/100);		
   Text1=  "Change : " ..win32.formatNumber(Change, false, 2) .. "%"
   elseif Type == "Pip" then
    Change= (source.close[source.close:size()-1]- source.close[p])/(source:pipSize());		
   Text1=  "Change : " ..win32.formatNumber(Change, false, 2) .. "Pips"
   else
   
    Change1= (source.close[source.close:size()-1]- source.close[p])/(source.close[p]/100);
	Change2= (source.close[source.close:size()-1]- source.close[p])/(source:pipSize());		
   
   Text1=  "Change : " ..win32.formatNumber(Change1, false, 2) .. "%"
   Text2=       "Change : " ..win32.formatNumber(Change2, false, 2) .. "Pips"
   end
 
	 
   local i=1;	 
   width, height = context:measureText (1, Text1, 0);
   
   if  Type ~= "Both" then
   
   if Change > 0 then
   context:drawText (1,  Text1, Up, -1,  iX(context,width,0,1) ,  iY(context,height,i,0) ,iX(context,width,0,2),iY(context,height,i,1), 0 );	
   else
   context:drawText (1,  Text1, Down, -1,  iX(context,width,0,1) ,  iY(context,height,i,0) ,iX(context,width,0,2),iY(context,height,i,1), 0 );	
   end
   else
   
       if Change1 > 0 then
	   context:drawText (1,  Text1, Up, -1,  iX(context,width,0,1) ,  iY(context,height,i,0) ,iX(context,width,0,2),iY(context,height,i,1), 0 );	
	   else
	   context:drawText (1,  Text1, Down, -1,  iX(context,width,0,1) ,  iY(context,height,i,0) ,iX(context,width,0,2),iY(context,height,i,1), 0 );	
	   end
	   
	     if Change2 > 0 then
	   context:drawText (1,  Text2, Up, -1,  iX(context,width,0,1) ,  iY(context,height,i+1,0) ,iX(context,width,0,2),iY(context,height,i+1,1), 0 );	
	   else
	   context:drawText (1,  Text2, Down, -1,  iX(context,width,0,1) ,  iY(context,height,i+1,0) ,iX(context,width,0,2),iY(context,height,i+1,1), 0 );	
	   end
   
   
   end
   
   

end		

function GetDate()

local olddate = source:date(source:size()-1);       -- bar date;
  
local table = core.dateToTable (olddate);
 local newdate=core.datetime (table.year, table.month, table.day, From, 0, 0);
 
 if newdate> source:date(source:size()-1) then
 newdate=newdate-1;
 end
 
 
 local p = core.findDate (source, newdate, false);

 if p== -1 then
 return 0;
 else
 return p;
 end
	
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