-- Id: 21521
-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=9673


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--|                                                                   Developed by : Mario Jemic   |                    
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--|BitCoin Address            : 15VCJTLaz12Amr7adHSBtL9v8XomURo9RF                                 |
--|Ethereum Address           : 0x8C110cD61538fb6d7A2B47858F0c0AaBd663068D                         |
--|Cardano/ADA                : addr1v868jza77crzdc87khzpppecmhmrg224qyumud6utqf6f4s99fvqv         |  
--|Dogecoin Address           : DNDTFfmVa2Gjts5YvSKEYaiih6cums2L6C                                 |
--|Binance(ERC20 & BSC only)  : 0xe84751063de8ade7c5fbff5e73f6502f02af4e2c                         |                                                  |   
--+------------------------------------------------------------------------------------------------+

function Init()
	indicator:name("Generic Dow Jones Index")
	indicator:description("")
	indicator:requiredSource(core.Bar)
	indicator:type(core.Oscillator)

	indicator.parameters:addInteger("Base", "Price Type", "", 1)
	indicator.parameters:addIntegerAlternative("Base", "USD", "", 1)
	indicator.parameters:addIntegerAlternative("Base", "JPY", "", 2)

	indicator.parameters:addGroup("Display")
	indicator.parameters:addColor("color", "Index Color", "", core.rgb(255, 0, 0))
	indicator.parameters:addInteger("width", "Line width", "", 1, 1, 5)
	indicator.parameters:addInteger("style", "Line style", "", core.LINE_SOLID)
	indicator.parameters:setFlag("style", core.FLAG_LINE_STYLE)
end

local source
local Instrument = {}
Instrument[1] = {"EUR/USD", "USD/JPY", "GBP/USD", "AUD/USD"}
Instrument[2] = {"USD/JPY", "EUR/JPY", "AUD/JPY", "NZD/JPY"}
local usdx
local loading = {}
local Source = {}
local dayoffset
local weekoffset
local Weight = {}
Weight[1] = {7479, 812150, 6410, 9787}
Weight[2] = {123, 92, 121, 158}
local Base
local BaseLabel = {"USD", "JPY"}

local Inverse = {}
local pattern = "(%a%a%a)/(%a%a%a)"

local MyFirst=false;
-- prepare the indicator
function Prepare(nameOnly)
	source = instance.source

	local name = profile:id()
	instance:name(name)
	if nameOnly then
		return
	end

	local First, Second

	Base = instance.parameters.Base

	dayoffset = core.host:execute("getTradingDayOffset")
	weekoffset = core.host:execute("getTradingWeekOffset")

	for i = 1, 4, 1 do
		InstrumentFlag = core.host:findTable("offers"):find("Instrument", Instrument[Base][i])
		assert(InstrumentFlag ~= nil, "Subscribed to " .. Instrument[Base][i])

		Source[i] =
			core.host:execute("getSyncHistory", Instrument[Base][i], source:barSize(), source:isBid(), 0, 100 + i, 200 + i)
		loading[i] = true

		First, Second = string.match(Instrument[Base][i], pattern)
		if First == BaseLabel[Base] then
			Inverse[i] = true
		else
			Inverse[i] = false
		end
	end

	Index = instance:addStream(BaseLabel[Base], core.Line, BaseLabel[Base], BaseLabel[Base], instance.parameters.color, 0)
	Index:setPrecision(math.max(2, instance.source:getPrecision()))
	Index:setWidth(instance.parameters.width)
	Index:setStyle(instance.parameters.style)
	MyFirst=false
end

-- the function which is called to calculate the period
function Update(period)
	local Flag = true
	local p = {}

	for i = 1, 4, 1 do
		if loading[i] then
			Flag = false
		end
	end

	if not Flag then
		return
	end

	Flag = true

	for i = 1, 4, 1 do
		p[i] = Initialization(i, period)
		if p[i] == false then
			Flag = false
		end
	end

	if not Flag then
		return
	end

	--[$80,000–(EURUSD × €7,479)–(GBPUSD × £6,410) – (¥812,150 / USDJPY)–(AUDUSD × AU$9,787)]/4
	local x = 0
	for i = 1, 4, 1 do
		if Inverse[i] then
			x = x + (20000 - Weight[Base][i] / Source[i].close[p[i]])
		else
			x = x + (20000 - Source[i].close[p[i]] * Weight[Base][i])
		end
	end
	Index[period] = x / 4
end

function Initialization(id, period)
	local Candle
	Candle = core.getcandle(source:barSize(), source:date(period), dayoffset, weekoffset)

	if loading[id] or Source[id]:size() == 0 then
		return false
	end

	if period < source:first() then
		return false
	end

	local p = core.findDate(Source[id], Candle, false)

	-- candle is not found
	if p < 0 then
		return false
	else
		return p
	end
end

-- the function is called when the async operation is finished
function AsyncOperationFinished(cookie)
	local Flag = true

	for i = 1, 4, 1 do
		if cookie == 100 + i then
			loading[i] = false
		elseif cookie == 200 + i then
			loading[i] = true
			Flag = false
		end
	end

	if Flag then
		instance:updateFrom(0)
	end

	return core.ASYNC_REDRAW
end