station_cfg = {}
dofile("wifi.lua")
mqtt_host = "mqtt.derf0.net"

chip_id = string.format("%06X", node.chipid())
device_id = "esp8266_" .. chip_id
mqtt_prefix = "sensor/" .. device_id
mqttclient = mqtt.Client(device_id, 120)
sleep_time = 800

adc_mul = 467
adc_div = 104

influx_url = 'http://192.168.0.200:8086/write?db=sensors'
influx_attr = string.format(",area=hm17_,location=%s", device_id)

print("https://wiki.chaosdorf.de/Sensorium")
print("ESP8266 " .. chip_id)

gpio.mode(6, gpio.OUTPUT)
gpio.mode(5, gpio.OUTPUT)
gpio.write(6, 1)
gpio.write(5, 1)
i2c.setup(0, 1, 2, i2c.SLOW)

if not bme280.setup() then
	print("BME280 setup failed")
end

function get_battery_mv()
	return adc.read(0) * adc_mul / adc_div
end

function get_battery_percent(bat_mv)
	if bat_mv > 4160 then
		return 100
	end
	if bat_mv < 3360 then
		return 0
	end
	return (bat_mv - 3360) / 8
end

function connect_mqtt()
	print("IP address: " .. wifi.sta.getip())
	print("Connecting to MQTT " .. mqtt_host)
	mqttclient:on("connect", hass_register)
	mqttclient:connect(mqtt_host)
end

function connect_wifi()
	print("WiFi MAC: " .. wifi.sta.getmac())
	print("Connecting to ESSID " .. station_cfg.ssid)
	wifi.eventmon.register(wifi.eventmon.STA_GOT_IP, connect_mqtt)
	wifi.setmode(wifi.STATION)
	wifi.sta.config(station_cfg)
	wifi.sta.connect()
end

function publish_reading()
	local T, P, H, QNH = bme280.read(120)
	local bat_mv = get_battery_mv()
	local bat_percent = get_battery_percent(bat_mv)
	local rssi = wifi.sta.getrssi()

	if bat_mv > 4150 then
		sleep_time = 30
	elseif bat_mv < 3600 then
		sleep_time = 1600
	elseif bat_mv < 3900 then
		sleep_time = 800
	elseif bat_mv < 4060 then
		sleep_time = 400
	end

	if T == nil then
		print("BME280 readout failed")
		local json_str = string.format('{"battery_mv":%d,"battery_percent":%d,"rssi_dbm":%d}', bat_mv, bat_percent, rssi)
		mqttclient:publish(mqtt_prefix .. "/data", json_str, 0, 0, function(client)
			naptime()
		end)
		return
	end

	local Tsgn = (T < 0 and -1 or 1)
	T = Tsgn*T
	local temp = string.format("%s%d.%02d", Tsgn<0 and "-" or "", T/100, T%100)
	local humi = string.format("%d.%03d", H/1000, H%1000)
	local pressure = string.format("%d.%03d", P/1000, P%1000)
	local sealevel = string.format("%d.%03d", QNH/1000, QNH%1000)

	local json_str = string.format('{"temperature_celsius":%s,"humidity_relpercent":%s,"pressure_hpa":%s,"pressure_sealevel_hpa":%s,"battery_mv":%d,"battery_percent":%d,"rssi_dbm":%d}', temp, humi, pressure, sealevel, bat_mv, bat_percent, rssi)
	mqttclient:publish(mqtt_prefix .. "/data", json_str, 0, 0, function(client)
		if influx_url and influx_attr then
			publish_influx(temp, humi, pressure, rssi, bat_mv)
		else
			naptime()
		end
	end)
end

function publish_influx(temp, humi, pressure, rssi_dbm, bat_mv)
	http.post(influx_url, nil, string.format("bme280%s temperature_celsius=%s,humidity_relpercent=%s,pressure_hpa=%s", influx_attr, temp, humi, pressure), function(code, data)
		http.post(influx_url, nil, string.format("esp8266%s rssi_dbm=%d,battery_mv=%d", influx_attr, rssi_dbm, bat_mv), function(code, data)
			naptime()
		end)
	end)
end

function hass_register()
	local hass_device = string.format('{"connections":[["mac","%s"]],"identifiers":["%s"],"model":"ESP8266","name":"Sensorium %s","manufacturer":"derf"}', wifi.sta.getmac(), device_id, chip_id)
	local hass_entity_base = string.format('"device":%s,"state_topic":"%s/data","expire_after":1800', hass_device, mqtt_prefix, mqtt_prefix)
	local hass_temperature = string.format('{%s,"name":"Temperature","object_id":"%s_temperature","unique_id":"%s_temperature","device_class":"temperature","unit_of_measurement":"°c","value_template":"{{value_json.temperature_celsius}}"}', hass_entity_base, device_id, device_id)
	local hass_humidity = string.format('{%s,"name":"Humidity","object_id":"%s_humidity","unique_id":"%s_humidity","device_class":"humidity","unit_of_measurement":"%%","value_template":"{{value_json.humidity_relpercent}}"}', hass_entity_base, device_id, device_id)
	local hass_pressure = string.format('{%s,"name":"Pressure","object_id":"%s_pressure","unique_id":"%s_pressure","device_class":"pressure","unit_of_measurement":"hPa","value_template":"{{value_json.pressure_hpa}}"}', hass_entity_base, device_id, device_id)
	local hass_battery = string.format('{%s,"name":"Battery","object_id":"%s_battery","unique_id":"%s_battery","device_class":"battery","unit_of_measurement":"%%","value_template":"{{value_json.battery_percent}}","entity_category":"diagnostic"}', hass_entity_base, device_id, device_id)
	mqttclient:publish("homeassistant/sensor/" .. device_id .. "/temperature/config", hass_temperature, 0, 1, function(client)
		mqttclient:publish("homeassistant/sensor/" .. device_id .. "/humidity/config", hass_humidity, 0, 1, function(client)
			mqttclient:publish("homeassistant/sensor/" .. device_id .. "/pressure/config", hass_pressure, 0, 1, function(client)
				mqttclient:publish("homeassistant/sensor/" .. device_id .. "/battery/config", hass_battery, 0, 1, function(client)
					publish_reading()
				end)
			end)
		end)
	end)
end

function naptime()
	if sleep_time < 40 then
		print("Waiting")
		go_to_sleep:start(true)
		local next_reading = tmr.create()
		next_reading:register(sleep_time * 1000, tmr.ALARM_SINGLE, publish_reading)
		next_reading:start()
	else
		print("Naptime")
		gpio.write(5, 0)
		gpio.write(6, 0)
		rtctime.dsleep(sleep_time * 1000000)
	end
end

go_to_sleep = tmr.create()
go_to_sleep:register(40 * 1000, tmr.ALARM_SEMI, naptime)
go_to_sleep:start()

connect_wifi()