-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=6486

--+------------------------------------------------------------------+
--|                               Copyright © 2018, Gehtsoft USA LLC |
--|                                            http://fxcodebase.com |
--+------------------------------------------------------------------+
--|                                 Support our efforts by donating  |
--|                                    Paypal: https://goo.gl/9Rj74e |
--|                    BitCoin : 15VCJTLaz12Amr7adHSBtL9v8XomURo9RF  |
--|                BitCoin Cash: 1BEtS465S3Su438Kc58h2sqvVvHK9Mijtg  |
--|           Ethereum : 0x8C110cD61538fb6d7A2B47858F0c0AaBd663068D  |
--|                   LiteCoin : LLU8PSY2vsq7B9kRELLZQcKf5nJQrdeqwD  |
--+------------------------------------------------------------------+

function Init()
    indicator:name("CCI gradient indicator");
    indicator:description("CCI gradient indicator");
    indicator:requiredSource(core.Bar);
    indicator:type(core.Indicator);

    indicator.parameters:addGroup("Calculation");
    indicator.parameters:addInteger("Period", "Period", "", 14);

    indicator.parameters:addGroup("Style");
    indicator.parameters:addString("UPclr", "UP color", "", "Green");
    indicator.parameters:addStringAlternative("UPclr", "Red", "", "Red");
    indicator.parameters:addStringAlternative("UPclr", "Green", "", "Green");
    indicator.parameters:addStringAlternative("UPclr", "Blue", "", "Blue");
    indicator.parameters:addString("DNclr", "DN color", "", "Red");
    indicator.parameters:addStringAlternative("DNclr", "Red", "", "Red");
    indicator.parameters:addStringAlternative("DNclr", "Green", "", "Green");
    indicator.parameters:addStringAlternative("DNclr", "Blue", "", "Blue");
    indicator.parameters:addDouble("Depth", "Depth", "", 0.005);
end

local first;
local source = nil;
local Period;
local UPclr;
local DNclr;
local Depth;
local CCI;
local open=nil;
local close=nil;
local high=nil;
local low=nil;

function Prepare(nameOnly)
    source = instance.source;
    Period=instance.parameters.Period;
    UPclr=instance.parameters.UPclr;
    DNclr=instance.parameters.DNclr;
    Depth=instance.parameters.Depth;
  
    local name = profile:id() .. "(" .. source:name() .. ", " .. instance.parameters.Period .. ")";
    instance:name(name);
    if nameOnly then
        return;
    end
  
    CCI = core.indicators:create("CCI", source, Period);
    first = CCI.DATA:first();
    open = instance:addStream("open", core.Line, name, "open", core.rgb(0, 0, 0), first)
    high = instance:addStream("high", core.Line, name, "high", core.rgb(0, 0, 0), first)
    low = instance:addStream("low", core.Line, name, "low", core.rgb(0, 0, 0), first)
    close = instance:addStream("close", core.Line, name, "close", core.rgb(0, 0, 0), first)
    instance:createCandleGroup("CCI color candle", "", open, high, low, close);
end

function Update(period, mode)
   if (period>first) then
    CCI:update(mode);
    open[period]=source.open[period];
    close[period]=source.close[period];
    high[period]=source.high[period];
    low[period]=source.low[period];
    local R=0;
    local G=0;
    local B=0;
    local CCIvalue=CCI.DATA[period];
    if CCIvalue>0 then
     if UPclr=="Red" then
      R=math.min(CCIvalue*Depth*255,255);
     elseif UPclr=="Green" then
      G=math.min(CCIvalue*Depth*255,255);
     else
      B=math.min(CCIvalue*Depth*255,255);
     end
    else
     if DNclr=="Red" then
      R=math.min(-CCIvalue*Depth*255,255);
     elseif DNclr=="Green" then
      G=math.min(-CCIvalue*Depth*255,255);
     else
      B=math.min(-CCIvalue*Depth*255,255);
     end
    end
    open:setColor(period,core.rgb(R,G,B));
   end 
end