-- Id: 12110
-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=3846

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function Init()
    indicator:name("Indicator Divergence");
    indicator:description("");
    indicator:requiredSource(core.Bar);
	indicator:setTag("AllowAllSources", "y");
    indicator:type(core.Oscillator);

    indicator.parameters:addString("IN", "Indicator", "", "");
    indicator.parameters:setFlag("IN",core.FLAG_INDICATOR);
    indicator.parameters:addInteger("Stream", "Stream Number", "Stream Numbers", 1);
	
	indicator.parameters:addString("Price", "Price", "", "close");
    indicator.parameters:addStringAlternative("Price", "close", "", "close");
    indicator.parameters:addStringAlternative("Price", "open", "", "open");
    indicator.parameters:addStringAlternative("Price", "high", "", "high");
    indicator.parameters:addStringAlternative("Price", "low", "", "low");
    indicator.parameters:addStringAlternative("Price", "median", "", "median");
    indicator.parameters:addStringAlternative("Price", "typical", "", "typical");
    indicator.parameters:addStringAlternative("Price", "weighted", "", "weighted");
    indicator.parameters:addInteger("Frames", "Frames", "Frames", 5);
	
	
    indicator.parameters:addBoolean("I", "Indicator mode", "Keep true value to display labels and lines. Set this parameter to false when the indicator is used in another indicator.", true);
    indicator.parameters:addColor("D_color", "Color of Divergence line", "", core.rgb(0, 155, 255));
    indicator.parameters:addColor("UP_color", "Color of Uptrend", "", core.rgb(255, 0, 0));
    indicator.parameters:addColor("DN_color", "Color of Downtend", "", core.rgb(0, 255, 0));
end

-- Indicator instance initialization routine
-- Processes indicator parameters and creates output streams
-- Parameters block
local I;
local DD;
local UP_color;
local DN_color;
local Price;
local Frames;

local first;
local source = nil;

-- Streams block
local D = nil;
local UP = nil;
local DN = nil;
local Ind = nil;
local lineid = nil;
 
local Stream;
-- Routine
function Prepare(nameOnly)
    I = instance.parameters.I;
    DD = instance.parameters.DD;
    Price = instance.parameters.Price;
    UP_color = instance.parameters.UP_color;
    DN_color = instance.parameters.DN_color;
    Frames = instance.parameters.Frames;	
    source = instance.source;
    local name = profile:id() .. "(" .. source:name() .. ", " .. instance.parameters.IN .. ")";
    instance:name(name);
    if nameOnly then
        return;
    end
    local ind_ = core.indicators:findIndicator(instance.parameters:getString("IN"));
    local params = instance.parameters:getCustomParameters("IN");
    if  ind_:requiredSource() == core.Tick  and source:isBar() then
			 if Price=="close" then
			  Ind = ind_:createInstance(source.close, params);
			 elseif Price=="open" then
			  Ind = ind_:createInstance(source.open, params);
			 elseif Price=="high" then
			  Ind = ind_:createInstance(source.high, params);
			 elseif Price=="low" then
			  Ind = ind_:createInstance(source.low, params);
			 elseif Price=="median" then
			  Ind = ind_:createInstance(source.median, params);
			 elseif Price=="typical" then
			  Ind = ind_:createInstance(source.typical, params);
			 else
			  Ind = ind_:createInstance(source.weighted, params);
			 end
    elseif       source:isBar()  or   ( ind_:requiredSource() == core.Tick and not  source:isBar() ) then
     Ind = ind_:createInstance(source, params);
	
    end 
   
    
    if Ind~= nil then
	
	
	 
	if instance.parameters.Stream > Ind:getStreamCount () then
	Stream=1;
	else
	Stream=instance.parameters.Stream;
	end
	
	first = Ind:getStream(Stream-1):first(); 
	
	else first = source:first() end

    D = instance:addStream(instance.parameters.IN, core.Line, name .. "." .. instance.parameters.IN, instance.parameters.IN, instance.parameters.D_color, first, -1);
    D:setPrecision(math.max(2, instance.source:getPrecision()));
    if I then
        UP = instance:createTextOutput ("Up", "Up", "Wingdings", 10, core.H_Center, core.V_Top, instance.parameters.UP_color, -1);
        DN = instance:createTextOutput ("Dn", "Dn", "Wingdings", 10, core.H_Center, core.V_Bottom, instance.parameters.DN_color, -1);
    else
        UP = instance:addStream("UP", core.Bar, name .. ".UP", "UP", instance.parameters.D_color, first, -1);
    UP:setPrecision(math.max(2, instance.source:getPrecision()));
        DN = instance:addStream("DN", core.Bar, name .. ".DN", "DN", instance.parameters.D_color, first, -1);
    DN:setPrecision(math.max(2, instance.source:getPrecision()));
    end
end

local pperiod = nil;
local pperiod1 = nil;
local line_id = 0;

-- Indicator calculation routine
function Update(period, mode)
    period = period - 1;

	  -- if recaclulation started - remove all
    if pperiod ~= nil and pperiod > period then
        core.host:execute("removeAll");
    end
    pperiod = period;
    -- process only candles which are already closed closed.
    if pperiod1 ~= nil and pperiod1 == source:serial(period) then
        return ;
    end
    pperiod1 = source:serial(period)
   

	if Ind== nil then
    return;
    end
	
    Ind:update(mode);
	
    if period >= first then
        D[period] = Ind:getStream(Stream-1)[period];
        if period >= first + 2 then
            processBullish(period - 2);
            processBearish(period - 2);
        end
    end
 
end

function processBullish(period)
    if isTrough(period) then
        local curr, prev;
        curr = period;
        prev = prevTrough(period);
        if prev ~= nil then
		
		if source:isBar() then
            if Ind:getStream(Stream-1)[curr] > Ind:getStream(Stream-1)[prev] and source.low[curr] < source.low[prev] then
                if I then
                    DN:set(curr, Ind:getStream(Stream-1)[curr], "\225", "Classic bullish");
                    line_id = line_id + 1;
                    core.host:execute("drawLine", line_id, source:date(prev), Ind:getStream(Stream-1)[prev], source:date(curr), Ind:getStream(Stream-1)[curr], DN_color);
                else
                    DN[period] = curr - prev;
                end
            elseif Ind:getStream(Stream-1)[curr] < Ind:getStream(Stream-1)[prev] and source.low[curr] > source.low[prev] then
                if I then
                    DN:set(curr, Ind:getStream(Stream-1)[curr], "\225", "Reversal bullish");
                    line_id = line_id + 1;
                    core.host:execute("drawLine", line_id, source:date(prev), Ind:getStream(Stream-1)[prev], source:date(curr), Ind:getStream(Stream-1)[curr], DN_color);
                else
                    DN[period] = -(curr - prev);
                end
            end
		else
		if Ind:getStream(Stream-1)[curr] > Ind:getStream(Stream-1)[prev] and source[curr] < source[prev] then
                if I then
                    DN:set(curr, Ind:getStream(Stream-1)[curr], "\225", "Classic bullish");
                    line_id = line_id + 1;
                    core.host:execute("drawLine", line_id, source:date(prev), Ind:getStream(Stream-1)[prev], source:date(curr), Ind:getStream(Stream-1)[curr], DN_color);
                else
                    DN[period] = curr - prev;
                end
            elseif Ind:getStream(Stream-1)[curr] < Ind:getStream(Stream-1)[prev] and source[curr] > source[prev] then
                if I then
                    DN:set(curr, Ind:getStream(Stream-1)[curr], "\225", "Reversal bullish");
                    line_id = line_id + 1;
                    core.host:execute("drawLine", line_id, source:date(prev), Ind:getStream(Stream-1)[prev], source:date(curr), Ind:getStream(Stream-1)[curr], DN_color);
                else
                    DN[period] = -(curr - prev);
                end
            end
        end		
        end

    end
end

function isTrough(period)
    local i;
    if Ind:getStream(Stream-1)[period] < Ind:getStream(Stream-1)[period - 1] and Ind:getStream(Stream-1)[period] < Ind:getStream(Stream-1)[period + 1] then
        for i = period - 1, period-Frames, -1 do
            if i<=first then
             return true;
            end
            if Ind:getStream(Stream-1)[period]>Ind:getStream(Stream-1)[i] then
             return false;
            end
        end
        return true;
    end
    return false;
end

function prevTrough(period)
    local i;
    for i = period - 5, first, -1 do
        if Ind:getStream(Stream-1)[i] <= Ind:getStream(Stream-1)[i - 1] and Ind:getStream(Stream-1)[i] < Ind:getStream(Stream-1)[i - 2] and
           Ind:getStream(Stream-1)[i] <= Ind:getStream(Stream-1)[i + 1] and Ind:getStream(Stream-1)[i] < Ind:getStream(Stream-1)[i + 2] then
           return i;
        end
    end
    return nil;
end

function processBearish(period)
    if isPeak(period) then
        local curr, prev;
        curr = period;
        prev = prevPeak(period);
        if prev ~= nil then
		
		   if source:isBar() then
            if Ind:getStream(Stream-1)[curr] < Ind:getStream(Stream-1)[prev] and source.high[curr] > source.high[prev] then
                if I then
                    UP:set(curr, Ind:getStream(Stream-1)[curr], "\226", "Classic bearish");
                    line_id = line_id + 1;
                    core.host:execute("drawLine", line_id, source:date(prev), Ind:getStream(Stream-1)[prev], source:date(curr), Ind:getStream(Stream-1)[curr], UP_color);
                else
                    UP[period] = curr - prev;
                end
            elseif Ind:getStream(Stream-1)[curr] > Ind:getStream(Stream-1)[prev] and source.high[curr] < source.high[prev] then
                if I then
                    UP:set(curr, Ind:getStream(Stream-1)[curr], "\226", "Reversal bearish");
                    line_id = line_id + 1;
                    core.host:execute("drawLine", line_id, source:date(prev), Ind:getStream(Stream-1)[prev], source:date(curr), Ind:getStream(Stream-1)[curr], UP_color);
                else
                    UP[period] = -(curr - prev);
                end
            end
		else
		    if Ind:getStream(Stream-1)[curr] < Ind:getStream(Stream-1)[prev] and source [curr] > source [prev] then
                if I then
                    UP:set(curr, Ind:getStream(Stream-1)[curr], "\226", "Classic bearish");
                    line_id = line_id + 1;
                    core.host:execute("drawLine", line_id, source:date(prev), Ind:getStream(Stream-1)[prev], source:date(curr), Ind:getStream(Stream-1)[curr], UP_color);
                else
                    UP[period] = curr - prev;
                end
            elseif Ind:getStream(Stream-1)[curr] > Ind:getStream(Stream-1)[prev] and source [curr] < source [prev] then
                if I then
                    UP:set(curr, Ind:getStream(Stream-1)[curr], "\226", "Reversal bearish");
                    line_id = line_id + 1;
                    core.host:execute("drawLine", line_id, source:date(prev), Ind:getStream(Stream-1)[prev], source:date(curr), Ind:getStream(Stream-1)[curr], UP_color);
                else
                    UP[period] = -(curr - prev);
                end
            end
		    
        end		
        end

    end
end

function isPeak(period)
    local i;
    if Ind:getStream(Stream-1)[period] > Ind:getStream(Stream-1)[period - 1] and Ind:getStream(Stream-1)[period] > Ind:getStream(Stream-1)[period + 1] then
        for i = period - 1, period-Frames, -1 do
            if i<=first then
             return true;
            end
            if Ind:getStream(Stream-1)[period]<Ind:getStream(Stream-1)[i] then
             return false;
            end
        end
        return true;
    end
    return false;
end

function prevPeak(period)
    local i;
    for i = period - 5, first, -1 do
        if Ind:getStream(Stream-1)[i] >= Ind:getStream(Stream-1)[i - 1] and Ind:getStream(Stream-1)[i] > Ind:getStream(Stream-1)[i - 2] and
           Ind:getStream(Stream-1)[i] >= Ind:getStream(Stream-1)[i + 1] and Ind:getStream(Stream-1)[i] > Ind:getStream(Stream-1)[i + 2] then
           return i;
        end
    end
    return nil;
end