-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=64075
-- Id: 17689

--+------------------------------------------------------------------+
--|                               Copyright © 2018, Gehtsoft USA LLC |
--|                                            http://fxcodebase.com |
--+------------------------------------------------------------------+
--|                                      Developed by : Mario Jemic  |
--|                                          mario.jemic@gmail.com   |
--+------------------------------------------------------------------+
--|                                 Support our efforts by donating  |
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--+------------------------------------------------------------------+

function Init()
	indicator:name("Since Last Advanced Fractal")
	indicator:description("")
	indicator:requiredSource(core.Bar)
	indicator:type(core.Oscillator)

	indicator.parameters:addGroup("Calculation")
	indicator.parameters:addInteger("Frame", "Number of fractals (Odd)", "Number of fractals (Odd)", 5, 5, 99)

	indicator.parameters:addGroup("Style")

	indicator.parameters:addColor("Color1", "Color of Since Up", "Color of Since", 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("Color2", "Color of Since Down ", "Color of Since", 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
-- 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 first
local source = nil
local SignalUp, SignalDown
local SignalUp, SignalDown
local Up, Down
-- Routine
function Prepare(nameOnly)
	source = instance.source

	frame = instance.parameters.Frame

	if math.mod(frame, 2) ~= 0 then
		frame = frame + 1
	end

	first = source:first() + frame

	local name
	name = profile:id() .. "( " .. source:name() .. " )"
	instance:name(name)

	if (not (nameOnly)) then
		SignalUp = instance:addInternalStream(0, 0)
		SignalDown = instance:addInternalStream(0, 0)

		Up = instance:addStream("Up", core.Line, name .. ".Since Up", "Since Up", instance.parameters.Color1, source:first())
    Up:setPrecision(math.max(2, instance.source:getPrecision()));
		Up:setWidth(instance.parameters.Width1)
		Up:setStyle(instance.parameters.Style1)

		Down =
			instance:addStream(
			"Down",
			core.Line,
			name .. ".Since Down",
			"Since Down",
			instance.parameters.Color2,
			source:first()
		)
    Down:setPrecision(math.max(2, instance.source:getPrecision()));
		Down:setWidth(instance.parameters.Width2)
		Down:setStyle(instance.parameters.Style2)
	end
end

local Last
-- Indicator calculation routine
-- TODO: Add your code for calculation output values
function Update(period)
	if (period < first) then
		return
	end

	------------------------------------------------------------------------------------------------------------------

	local test = 0

	local hof = frame
	local i
	local count = 0

	for i = 1, frame, 1 do
		if hof > 1 then
			hof = hof - 2
			count = count + 1
		else
			count = count - 1
			break
		end
	end

	local x = period - count * 2

	SignalUp[period] = 0
	SignalDown[period] = 0
	SignalUp[period - count] = 0
	SignalDown[period - count] = 0

	local curr = source.high[period - count]

	for i = x, period, 1 do
		if curr > source.high[i] and i ~= (period - count) then
			test = test + 1
		end
	end

	if test == period - x then
		--  up:set(period - count, source.high[period - count], "\226");
		SignalUp[period - count] = 1
	end

	test = 0

	curr = source.low[period - count]

	for i = x, period, 1 do
		if curr < source.low[i] and i ~= (period - count) then
			test = test + 1
		end
	end

	if test == period - x then
		-- down:set(period - count, source.low[period - count], "\225");
		SignalDown[period - count] = 1
	end

	-----------------------------------------------------------------------------------------------------------------

	local P1, P2 = findLast(period)

	if P1 == nil or P2 == nil then
		return
	end

	Up[period] = period - P1
	Down[period] = period - P2

	if Last == math.max(P1, P2) then
		return
	end

	Last = math.max(P1, P2)

	ReCalculate(P1, P2, period)
end

function ReCalculate(P1, P2, End)
	for period = math.min(P1, P2), End, 1 do
		if period >= P1 then
			Up[period] = period - P1
		end
		if period >= P2 then
			Down[period] = period - P2
		end
	end
end

function findLast(Start)
	local R1 = nil
	local R2 = nil

	for period = Start, first, -1 do
		if SignalUp[period] == 1 and R1 == nil then
			R1 = period
		end

		if SignalDown[period] == 1 and R2 == nil then
			R2 = period
		end

		if R1 ~= nil and R2 ~= nil then
			break
		end
	end

	return R1, R2
end