--
-- lua function to turn off/on SF SD Logs
--

--
--  variables for demo
--
local lastActive = 0													-- for demo: toggles SD Logs on/off every 5s
local interval = 500													
local enable = 0															

--
-- internal variables for SF SD Logs enable/disable function 
--
local nSF = 64																-- 64 SFs to consider
local logsSFIndex = nil												-- index of SF SD Logs
local logsTable = nil													-- copy of SF SD Logs data
local period = 10															-- default log period 10*100ms = 1.0s

-- init function
local function init()													

	-- init fuction for SD Logs enable/disable function
	local function initSDLogEnable()						-- initializes the SF SD Logs enable/disable function
		local createSF = false
		
		for i = 0, nSF-1 do												-- go through all SFs
			local cf = model.getCustomFunction(i)		-- get SF at index i

			if cf ~= nil then
				if cf.func == FUNC_LOGS then 					-- check if SF is SF SD Logs
					logsTable = cf											-- copy entry
					logsSFIndex = i											-- memorize index
					createSF = false										-- no need to create SF
					break																-- exit search loop
				end
				
				if logsSFIndex == nil and 						-- search for first free index
					 cf.switch == 0 then									
					logsSFIndex = i											-- memorize index
					createSF = true										  -- need to create the SF
				end
			end
		end
				
		if createSF == true then
			logsTable = { 
				["switch"] = getSwitchIndex('ON'),		-- trigger permanently ON 
				["func"] = FUNC_LOGS,									-- SD Logs
				["value"] = period,										-- 1.0s
				["active"] = 0 												-- disabled
			} 
		end
	end
	
	-- main init function
	initSDLogEnable()														-- Initialize the SF SD Logs enable/disable function
end

-- run function
local function run()
	local function SDLogsEnable(enable)					-- function to enable/disable SD Logs
		if logsTable ~= nil then
			logsTable.active = enable								-- enable/disable SD Logs SF
			model.setCustomFunction(logsSFIndex, logsTable)
		end
	end
	
	-- demo function to toggle disabled/enabled status
	local function demoSDLogsOnOff()
		local now = getTime()
	
		if now >= (lastActive + interval) then
			lastActive = now	
				
			if enable == 0 then
				enable = 1
			else
				enable = 0
			end

			SDLogsEnable(enable)
		end
	end
	
	-- main run function
	demoSDLogsOnOff()
end

return { init = init, run = run }