local flash_pin = 3    --> GPIO0

function debounce_button (func)
   local last = 0
   local delay = 50000 -- 50ms * 1000 as tmr.now() has μs resolution

   return function (...)
      local now = tmr.now()
      local delta = now - last
      if delta < 0 then delta = delta + 2147483647 end; -- proposed because of delta rolling over, https://github.com/hackhitchin/esp8266-co-uk/issues/2
      if delta < delay then return end;

      last = now
      return func(...)
   end
end

function read_button ()
   if gpio.read(flash_pin) == 0 then
      print("Rebooting back to original wifi configuration mode...")
      file.remove('config.lc')
      node.restart()
   end
end

led_pin = 4            --> GPIO2
value = gpio.HIGH
-- value = gpio.LOW
duration = 50    --> 1 second

function toggleLED ()
   if value == gpio.LOW then
       value = gpio.HIGH
   else
       value = gpio.LOW
   end

   gpio.write(led_pin, value)
end

gpio.mode(led_pin, gpio.OUTPUT)
gpio.write(led_pin, value)

sda = 2
scl = 3
alt=330 -- altitude of the measurement place

function read_bme280()
   mode = nil
   mode = bme280.init(sda, scl)
   -- print('mode=',mode,'\n')

   tmr.create():alarm(1000, tmr.ALARM_SINGLE, function()
      H, T = bme280.humi()
      h = H / 1000
      D = bme280.dewpoint(H, T)

      P = bme280.baro()
      QNH = bme280.qfe2qnh(P, alt)
      curAlt = bme280.altitude(P, QNH)
      P, T = bme280.baro()

      h = H / 1000
      t = T / 100
      d = D / 100
      p = P / 10000
      q = QNH / 10000
      a = curAlt

      tf = (t*9/5+32)
      df = (d*9/5+32)
      pi = (p*0.2953)
      qi = (q*0.2953)
   end)

   gpio.mode(flash_pin, gpio.INT, gpio.PULLUP)
   gpio.trig(flash_pin, 'both', debounce_button(read_button))

end

function upload_data()
   read_bme280()

   -- print("Temperature:" .. string.format("%.3f", t) .. " °C")
   -- print("Humidity:" .. string.format("%.3f", h) .. " %")
   -- print("Pressure:" .. string.format("%.3f", q) .. " KPa")
   -- print("Dewpoint:" .. string.format("%.3f", d) .. " °C\n")

   value = gpio.LOW
   gpio.write(led_pin, value)

   if (tsapikey ~= nil) then
      -- push to ThingSpeak
      host = "api.thingspeak.com"
      param =	'/update?key=' .. tsapikey ..
      '&field1=' .. string.format("%.3f", t) ..
      '&field2=' .. string.format("%.3f", h) ..
      '&field3=' .. string.format("%.3f", q) ..
      '&field4=' .. string.format("%.3f", d) 

      -- print(host .. param)
      port = 80
      -- print('Sending to ThingSpeak')
      send_request(host, port, param)
   end

   if (wuapiid ~= nil and wuapikey ~= nil) then
      -- push to WUnderground
      host = "rtupdate.wunderground.com"
      param = "/weatherstation/updateweatherstation.php?ID="..wuapiid.."&PASSWORD=".. wuapikey ..
      "&dateutc=now&tempf="..string.format("%.1f",tf).."&baromin="..string.format("%.3f",qi) ..
      "&humidity="..string.format("%.1f",h).."&dewptf="..string.format("%.1f",df) ..
      "&softwaretype=NodeMCU%20version%20.01&action=updateraw&realtime=1&rtfreq=2.5"

      -- print(host .. param)
      port = 80
      -- print('Sending to Wunderground')
      send_request(host, port, param)
   end

   value = gpio.HIGH
   gpio.write(led_pin, value)
end

function send_request(host, port, param)
   conn = nil
   conn = net.createConnection(net.TCP, 0)
   conn:on("receive", function (conn, payload)
      -- print("Posted")
      -- print(payload)
   end)

   -- once connected, request page
   conn:on ("connection", function(conn, payload)
      -- print("Connected")
      if port == 80 then
	  conn:send("GET " .. param.. " HTTP/1.1\r\nHost: " ..host.. " Connection: close\r\nAccept: */*\r\n User-Agent: Mozilla/5.1 (compatible; esp8266 Lua; Windows NT 5.1)\r\n\r\n")
      else
	  conn:send(param)
      end
   end)

   conn:on("disconnection", function(conn, payload) 
      -- print("Disconnected")
   end)

   conn:connect(port, host)

   -- release connection objects
   conn = nil
   payload = nil
end

local unescape = function (s)
   s = string.gsub(s, "+", " ")
   s = string.gsub(s, "%%(%x%x)", function (h)
         return string.char(tonumber(h, 16))
      end)
   return s
end

-- First reading data
read_bme280()
-- Periodic reading of the sensor
tmr.alarm(1, 20000, 1, function() upload_data() end)

srv=net.createServer(net.TCP)
srv:listen(wsport,
   function(conn)
      conn:on("receive",function(conn,payload) 

	 local _, _, method, path, vars = string.find(payload, "([A-Z]+) (.+)?(.+) HTTP")
	 if(method == nil)then
	     _, _, method, path = string.find(payload, "([A-Z]+) (.+) HTTP")
	 end

	 local _GET = {}
	 if (vars ~= nil)then
	     for k, v in string.gmatch(vars, "(%w+)=([^%&]+)&*") do
		 _GET[k] = unescape(v)
	     end
	 end

	 if (_GET.pin == "reboot") then
	    print("Reboot!")
            node.restart()
	 end

	 if (_GET.pin == "reconfigure") then
	    print("Reconfigure!")
	    file.remove('config.lc')
	    node.restart()
	 end

	 read_bme280()
	 -- print("Connection to webserver!")
	 --print(payload)
	 if string.match(payload, "machine") then
	    conn:send("\"Temperature\": \""..temp.."\", \"Humidity\": \""..humi.."\", \"Pressure\": \""..q.."\"")
	 else
	    buf = "HTTP/1.1 200 OK\r\nContent-Type: text/html\r\n\r\n<!DOCTYPE HTML>\r\n<html>"
	    buf = buf .. "<html><head><meta content='text/html;charset=utf-8'>"
	    buf = buf .. "<meta name='viewport' content='width=device-width, initial-scale=1'>"
	    buf = buf .. "<title>DareWeather BME280-Sensor ESP8266-Based Mini Weather Station</title></head>"
	    buf = buf .. "<body bgcolor='#ffffff'>"
	    buf = buf .. "<table border='1'>"
	    buf = buf .. "<tr bgcolor='#808080'><td colspan='2'><font color='#ffffff'>DareWeather Station</font></td></tr>"
	    buf = buf .. "<tr><td>Temperature</td><td>"..string.format('%.1f', t).."&deg;C</td></tr>"
	    buf = buf .. "<tr><td>Humidity</td><td>"..string.format('%.1f', h).."%</td></tr>"
	    buf = buf .. "<tr><td>Dewpoint</td><td>"..string.format('%.1f', d).."&deg;C</td></tr>"
	    buf = buf .. "<tr><td>Pressure</td><td>"..string.format('%.1f', q).."kPa</td></tr>"

            if (tschanid ~= nil and tsapikey ~= nil) then
               buf = buf .. "<tr><td>ThingSpeak</td><td><a href='https://thingspeak.com/channels/"..tschanid.."/private_show'>"..tschanid.."</a></td></tr>"
            end

            if (wuapiid ~= nil and wuapikey ~= nil) then
               buf = buf .. "<tr><td>Wunderground</td><td><a href='https://www.wunderground.com/personal-weather-station/dashboard?ID="..wuapiid.."'>"..wuapiid.."</a></td></tr>"
            end

            -- buf = buf .. "<tr><td><center><a href=\"?pin=reboot\"><button style='width:100%'>Reboot</button></a></td>"
            -- buf = buf .. "<td><a href=\"?pin=reconfigure\"><button>Reconfigure</button style='width:100%'></a></center></td></tr>"
	    buf = buf .. "</table>"
            buf = buf .. "</body></html>"

	    conn:send(buf)
	    conn:close()
	    collectgarbage()
	 end
		
      conn:on("sent",function(conn) conn:close() end) 
      conn = nil     
   end)
end)