local tmr = tmr
local wifi = wifi
local sta = wifi.sta
local eventmon = wifi.eventmon

local function Log (message, ...)
	if #arg > 0 then
		message = message:format(unpack(arg))
	end
	print (("%.6f %s"):format (tmr.now()/1000000, message))
end

local ip      = "192.168.2.73"	-- my IP (esp-07i)
local gateway = "192.168.2.7"	-- server IP
local netmask = "255.255.255.0"

local startup_delay = 50	-- ms
local sleep_time    = 2		-- seconds
local retry_max     = 1
local busy_time     = 1000	-- millis

local timeout = tmr.create()

local function dosleep()
	Log("deep sleep %ss\n", sleep_time)
	node.dsleep (sleep_time*1000000, 1, 1)	-- wakeup with WiFi, sleep immediately
end

local function have_connection()
	Log("have connection sta.status=%d sta.getip=%s/%s", sta.status(), sta.getip())
	dosleep()
end

local retry_count = 0

local function retry()
	if retry_count >= retry_max then
		Log ("retry failed")
		dosleep()
		return
	end
	retry_count = retry_count + 1
	Log ("retry %d", retry_count)

end

local function delay(ms)
	Log("busy delay %dms", ms)

	tmr.delay(ms*1000)

	Log("delay done")
end

local function wifi_setup()
	sta.setip({ip=ip, netmask=netmask, gateway=gateway})
	Log("sta.status=%d sta.getip=%s/%s", sta.status(), sta.getip())
end

local function dowifi()

	delay(busy_time)

	Log ("registering eventmons")
	eventmon.register(eventmon.STA_GOT_IP, function(T)
		Log("STA_GOT_IP")
		have_connection()
	end)

	eventmon.register(eventmon.STA_CONNECTED, function(T)
		Log("STA_CONNECTED")
	end)

	eventmon.register(eventmon.STA_DISCONNECTED, function(T)
		Log("DISCONNECTED reason %d", T.reason)
		retry()
	end)

	eventmon.register(eventmon.STA_AUTHMODE_CHANGE, function(T)
		Log("AUTHMODE_CHANGE")
	end)

	-- this is not expected - we do not use dhcp
	eventmon.register(eventmon.STA_DHCP_TIMEOUT, function(T)
		Log("STA_DHCP_TIMEOUT")
		retry()
	end)

	-- in case we were too late and missed the STA_GOT_IP event
	if wifi.STA_GOTIP == sta.status() then
		Log ("already connected")
		have_connection()
		return
	end
end

local function show_reason()
	local _, reset_reason, EXCCAUSE, EPC1, EPC2, EPC3, EXCVADDR, depc = node.bootreason()
	if (reset_reason ~= 0 and reset_reason ~= 5 and reset_reason ~= 6) then
		if (reset_reason == 2) then
			print(string.format("\treset_reason:%i EXCCAUSE:%i EPC1:%X EPC2:%X EPC3:%X EXCVADDR:%X DEPC:%i", reset_reason, EXCCAUSE, EPC1, EPC2, EPC3, EXCVADDR, depc))
		else
			print(string.format("\treset_reason:%i", reset_reason))
		end
	end  
end

local magic_pin = 1	-- gpio5 or D1

gpio.mode (magic_pin, gpio.INPUT, gpio.PULLUP)
if 0 == gpio.read (magic_pin) then
	Log ("aborting by magic")
else
	show_reason()
	wifi_setup()
	Log ("startup delayed %dms", startup_delay)
	timeout:alarm(startup_delay, tmr.ALARM_SINGLE, dowifi)
end