-- More information about this indicator can be found at:
-- http://fxcodebase.com/code/viewtopic.php?f=17&t=60738
-- Id: 11810

--+------------------------------------------------------------------+
--|                               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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--+------------------------------------------------------------------+

-- 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("Market Sessions ")
	indicator:description("Market Sessions ")
	indicator:requiredSource(core.Bar)
	indicator:type(core.Indicator)

	Add(1, "Sidney", -7, 9, core.rgb(255, 0, 0))
	Add(2, "Tokyo", -5, 9, core.rgb(0, 255, 0))
	Add(3, "London", 3, 9, core.rgb(0, 0, 255))
	Add(4, "New York", 8, 9, core.rgb(128, 128, 128))
	indicator.parameters:addGroup("Style")
	indicator.parameters:addInteger("Size", "Font Size", "Font Size", 10)
	indicator.parameters:addInteger("Transparency", "Fill Transparency", "0 - opaque, 100 - transparent", 50, 0, 100)
	indicator.parameters:addColor("Label", "label Color", "Label Color", core.rgb(0, 0, 0))
	indicator.parameters:addString("Placing", "Placing", "Placing", "Bottom")
	indicator.parameters:addStringAlternative("Placing", "Bottom", "Bottom", "Bottom")
	indicator.parameters:addStringAlternative("Placing", "Top", "Top", "Top")
end

function Add(id, Name, From, Length, Color)
	indicator.parameters:addGroup(id .. ". Session")

	indicator.parameters:addBoolean("On" .. id, "Show  This Session", "", true)
	indicator.parameters:addString("Name" .. id, "Session Name", "Session Name", Name)
	indicator.parameters:addDouble("From" .. id, "Session Start Time", "Session Start Time", From)
	indicator.parameters:addDouble("Length" .. id, "Session Length", "Session Length", Length)
	indicator.parameters:addColor("Color" .. id, "Session Color", "Session Color", Color)
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 Name = {}
local From = {}
local Length = {}
local first
local Transparency
local source = nil
--local ShowPriceTarget;
local Color = {}
local Count
local points
local Size
local Label
local Placing
-- Routine
function Prepare(nameOnly)
	source = instance.source
	first = source:first()
	Size = instance.parameters.Size
	Label = instance.parameters.Label
	Placing = instance.parameters.Placing

	Count = 0
	local i

	for i = 1, 4, 1 do
		if instance.parameters:getBoolean("On" .. i) then
			Count = Count + 1
			Color[Count] = instance.parameters:getDouble("Color" .. i)
			Name[Count] = instance.parameters:getString("Name" .. i)
			From[Count] = instance.parameters:getDouble("From" .. i)
			Length[Count] = instance.parameters:getDouble("Length" .. i)
		end
	end
	local name = profile:id() .. "(" .. source:name() .. ")"
	instance:name(name)
	if nameOnly then
		return
	end

	local s, e
	s, e = core.getcandle(source:barSize(), 0, 0, 0)
	s = math.floor(s * 86400 + 0.5) -- >>in seconds
	e = math.floor(e * 86400 + 0.5) -- >>in seconds

	local Flag
	if (e - s) <= 3600 then
		Flag = true
		core.host:execute("setStatus", " ")
	else
		Flag = false
		core.host:execute("setStatus", "Time Frame should be smaller than 1 hour ")
	end

	instance:ownerDrawn(Flag)
end

local init = false

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

	if not init then
		Transparency = context:convertTransparency(instance.parameters.Transparency / 2)
		init = true
		points = context:pixelsToPoints(Size)
		context:createFont(2, "Arial", points, points, 0)
	end

	context:setClipRectangle(context:left(), context:top(), context:right(), context:bottom())

	local first = math.max(first, context:firstBar())
	local last = math.min(context:lastBar(), source:size() - 1)

	local Start, End, Step

	if Placing == "Top" then
		Start = 1
		Stop = Count
		Step = 1
	else
		Start = Count
		Stop = 1
		Step = -1
	end

	for period = first, last, 1 do
		for session = Start, Stop, Step do
			DrawSession(session, context, period)
		end
	end
end

function Process(session, context, period)
	local date = source:date(period) -- bar date;

	local sfrom, sto

	-- 1) calculate the session to which the specified date belongs
	local t
	t = math.floor(date * 86400 + 0.5) -- date/time in seconds

	-- shift the date so it is in the virtual time zone in which 0:00 is the begin of the session
	t = t - From[session] * 3600
	-- truncate to the day only.
	t = math.floor(t / 86400 + 0.5) * 86400
	-- and shift it back to est time zone
	t = t + From[session] * 3600

	sfrom = t -- begin of the session
	sto = sfrom + Length[session] * 3600 -- end of the session

	sfrom = sfrom / 86400
	sto = sto / 86400

	if not (sto == date or sfrom == date) then
		return 0, 0
	end

	local p1 = core.findDate(source, sfrom, false)
	local p2 = core.findDate(source, sto, false)
	if p1 ~= -1 and p2 ~= -1 then
		local x1, x = context:positionOfBar(p1)
		local x2, x = context:positionOfBar(p2)
		return x1, x2
	else
		return 0, 0
	end
end

function DrawSession(session, context, period)
	local x1, x2 = Process(session, context, period)

	if x1 == 0 or x2 == 0 then
		return
	end
	context:createPen(1, 1, 1, Color[session])
	context:createSolidBrush(2, Color[session])
	local width, height = context:measureText(3, Name[session], context.LEFT)

	if Placing == "Top" then
		y1 = context:top() + height + (session - 1) * height
		y2 = context:top() + height + (session) * height
	else
		y1 = context:bottom() - height - (session) * height
		y2 = context:bottom() - height - (session - 1) * height
	end

	context:drawRectangle(1, 2, x1, y1, x2, y2, Transparency)
	context:drawText(3, Name[session], Label, -1, x1, y1, x2, y2, context.LEFT)
end

function Update(period)
end