-- Id: 214
-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=451

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-- Indicator profile initialization routine
-- Defines indicator profile properties and indicator parameters
function Init()
    indicator:name("Stochastic RSI");
    indicator:description("");
    indicator:requiredSource(core.Tick);
    indicator:type(core.Oscillator);

	indicator.parameters:addGroup("Calculation");
    indicator.parameters:addInteger("N", "Number of periods for RSI", "", 14, 1, 200);
    indicator.parameters:addInteger("K", "%K Stochastic Periods", "", 14, 1, 200);
    indicator.parameters:addInteger("KS", "%K Slowing Periods", "", 5, 1, 200);
    indicator.parameters:addInteger("D", "%D Slowing Stochastic Periods", "", 3, 1, 200);
	
	indicator.parameters:addGroup("Calculation");
    indicator.parameters:addColor("K_color", "Color of K", "Color of K", core.rgb(0, 255, 0));
	indicator.parameters:addInteger("width1", "Line width", "", 1, 1, 5);
	indicator.parameters:addInteger("style1", "Line style", "", core.LINE_SOLID);
	indicator.parameters:setFlag("style1", core.FLAG_LINE_STYLE);
    indicator.parameters:addColor("D_color", "Color of D", "Color of D", core.rgb(255, 0, 0));
	indicator.parameters:addInteger("width2", "Line width", "", 1, 1, 5);
	indicator.parameters:addInteger("style2", "Line style", "", core.LINE_SOLID);
	indicator.parameters:setFlag("style2", core.FLAG_LINE_STYLE);
end

-- Indicator instance initialization routine

-- Parameters block
local N;
local K;
local KS;
local D;

local firstSKI;
local firstK;
local firstD;
local source = nil;

-- Streams block
local SKI = nil;
local SK = nil;
local SD = nil;
local RSI = nil;
local MVA1 = nil;
local MVA2 = nil;

-- Routine
function Prepare(nameOnly)
    N = instance.parameters.N;
    K = instance.parameters.K;
    KS = instance.parameters.KS;
    D = instance.parameters.D;
    source = instance.source;
    first = source:first();

    local name = profile:id() .. "(" .. source:name() .. ", " .. N .. ", " .. K .. ", " .. KS ..", " .. D .. ")";
    instance:name(name);
    if nameOnly then
        return;
    end
    RSI = core.indicators:create("RSI", source, N);
    firstSKI = RSI.DATA:first() + K;
    SKI = instance:addInternalStream(firstSKI, 0);
    MVA1 = core.indicators:create("MVA", SKI, KS);
    firstK = MVA1.DATA:first();
    SK = instance:addStream("K", core.Line, name .. ".K", "K", instance.parameters.K_color, firstK);
    SK:setPrecision(math.max(2, instance.source:getPrecision()));
	SK:setWidth(instance.parameters.width1);
    SK:setStyle(instance.parameters.style1);
    SK:addLevel(20);
    SK:addLevel(50);
    SK:addLevel(80);
    MVA2 = core.indicators:create("MVA", SK, D);
    firstD = MVA2.DATA:first();
    SD = instance:addStream("D", core.Dot, name .. ".D", "D", instance.parameters.D_color, firstD);
    SD:setPrecision(math.max(2, instance.source:getPrecision()));
	SD:setWidth(instance.parameters.width2);
    SD:setStyle(instance.parameters.style2);
end

-- Indicator calculation routine
function Update(period, mode)
    RSI:update(mode);

    if (period >= firstSKI) then
        local min, max;
        --local range;
       -- range = core.rangeTo(period, K);
        min,max = mathex.minmax(RSI.DATA, period-K+1, period);
 
        if (min == max) then
            SKI[period] = 100;
        else
            SKI[period] = (RSI.DATA[period] - min) / (max - min) * 100;
        end
    end

    MVA1:update(mode);

    if period >= firstK then
        SK[period] = MVA1.DATA[period];
    end

    MVA2:update(mode);

    if (period >= firstD) then
        SD[period] = MVA2.DATA[period];
    end
end