-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=70510
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-- Available @ http://fxcodebase.com/code/viewtopic.php?f=17&t=70510

-- Indicator profile initialization routine
-- Defines indicator profile properties and indicator parameters
-- TODO: Add minimal and maximal value of numeric parameters and default color of the streams
function Init()
	indicator:name("Line")
	indicator:description("Line")
	indicator:requiredSource(core.Tick)
	indicator:type(core.Indicator)
	indicator.parameters:addGroup("Calculation")

	indicator.parameters:addString("Method", "Method", "Method", "Shift")
	indicator.parameters:addStringAlternative("Method", "Shift", "Shift", "Shift")
	indicator.parameters:addStringAlternative("Method", "Date", "Date", "Date")

	indicator.parameters:addInteger("Period", "Shift Period", "Period", 10)

	indicator.parameters:addInteger("lines", "Number of lines above/below", "", 10);
	indicator.parameters:addDouble("distance", "Distance between lines, pips", "", 2);

	indicator.parameters:addDate("Date", "Date", "Date", 0)
	indicator.parameters:setFlag("Date", core.FLAG_DATETIME)

	indicator.parameters:addGroup("Style")
	indicator.parameters:addColor("color", "Line Color", "Line Color", core.rgb(255, 0, 0))
	indicator.parameters:addColor("label", "Label Color", "Label Color", core.rgb(255, 0, 0))
	indicator.parameters:addInteger("size", "Font Size", "Font Size", 10)
	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)

	indicator.parameters:addBoolean("Show", "Show Label", "", true)
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 Period
local Method
local Hour
local first
local source = nil
local Date
-- Streams block
local Line = nil
local color
local extend
local label
local size
local Show, lines, distance
-- Routine
function Prepare(nameOnly)
	lines = instance.parameters.lines;
	distance = instance.parameters.distance;
	Period = instance.parameters.Period
	Method = instance.parameters.Method
	Date = instance.parameters.Date
	Hour = instance.parameters.Hour
	color = instance.parameters.color
	extend = instance.parameters.extend
	label = instance.parameters.label
	size = instance.parameters.size
	Show = instance.parameters.Show
	source = instance.source
	first = source:first()

	local name
	if Method == "Shift" then
		name = profile:id() .. "(" .. source:name() .. ", " .. tostring(Method) .. ", " .. tostring(Period) .. ")"
	else
		local ttime = core.dateToTable(core.host:execute("convertTime", 1, 4, Date))
		local dateDescr = string.format("%02i/%02i %02i:%02i", ttime.month, ttime.day, ttime.hour, ttime.min)

		name = profile:id() .. "(" .. source:name() .. ", " .. tostring(Method) .. ", " .. tostring(dateDescr) .. ")"
	end

	if (nameOnly) then
		return
	end

	instance:name(name)
	instance:ownerDrawn(true)
end

-- Indicator calculation routine
-- TODO: Add your code for calculation output values
function Update(period)
end

local init = false

function DrawLine(context, from, to, last)
	visible, y1 = context:pointOfPrice(from)
	visible, y2 = context:pointOfPrice(to)
	x1, x, x = context:positionOfBar(last)
	x2, x, x = context:positionOfBar(source:size() - 1)
	context:drawLine(1, x1, y1, x2, y2)
	Value = string.format("%." .. source:getPrecision() .. "f", from)

	if Show then
		width, height = context:measureText(3, Value, 0)
		context:drawText(3, Value, label, -1, x + width / 4, y2 - height, x + width + width / 4, y2, 0)
	end
	return Value;
end

function Draw(stage, context)
	if stage ~= 2 then
		return
	end

	if not init then
		context:createPen(1, context:convertPenStyle(instance.parameters.style), instance.parameters.width, color)
		context:createPen(2, context.DASH, instance.parameters.width, color)
		context:createFont(3, "Arial", context:pointsToPixels(size), context:pointsToPixels(size), 0)

		init = true
	end

	local Last = source:size() - 1
	local last
	local from, to;
	if Method == "Shift" then
		last = source:size() - 1 - Period
		if last < first then
			last = first
		end
	else
		last = core.findDate(source, Date, false)
		if last < first then
			last = first
		end
		if last > Last then
			last = Last
		end
	end
	Value = DrawLine(context, source[last], source[last], last);
	core.host:execute("setStatus", Value)
	for i = 1, lines, 1 do
		DrawLine(context, source[last] + distance * source:pipSize() * i, source[last] + distance * source:pipSize() * i, last);
		DrawLine(context, source[last] - distance * source:pipSize() * i, source[last] - distance * source:pipSize() * i, last);
	end
end