print("-----OWFS TIME-----")
-- OWFS path
OWFS_PATH = "/mnt/1wire/"
OWFS_TEMP_HUM_DEVICES = {	['26.160592010000'] = 'Krypgrund_SO',
									['26.740592010000'] = 'Krypgrund_SV',
									['26.802692010000'] = 'Krypgrund_NO',
									['26.1851E2010000'] = 'Ute' }

OWFS_TEMP_DEVICES = {	['28.1C3D99030000'] = "Avfuktare_Tilluft_Temp2",
								['28.87917A060000'] = "Avfuktare_Avluft_Temp2",
								['28.A9807B060000'] = "Avfuktare_Processluft_Temp2",
								['28.DC2E7A060000'] = "Avfuktare_Uteluft_Temp2" }

-- Onewire hub file
ONEWIRE_HUB_CONFIG_FILE       = "/mnt/1wire/uncached/EF.117120150000/hub/branch.BYTE"
ONEWIRE_HUB_PORT_CONFIG_VALUE = "15"
-- Cache file dir
OWFS_CACHEPATH = '/tmp'

-- Set how many readings in buffer
OWFS_BUFFERSIZE = 10

-- FUNCTIONS START --

--integer converts a float into an integer
function integer(x)
    return x<0 and math.ceil(x) or math.floor(x)
end

 -- deviceToTime returns a device time string in a format which can be used by the os.difftime function
function deviceToTime(time)
   return os.time { year  = string.sub(time, 1, 4),
                    month = string.sub(time, 6, 7),
                    day   = string.sub(time, 9, 10),
                    hour  = string.sub(time, 12, 13),
                    min   = string.sub(time, 15, 16),
                    sec   = string.sub(time, 18, 19) }
end

local function ReadFile(path)
    local file = io.open(path, "rb") -- r read mode and b binary mode
    if not file then
      return nil
    end
    local content = file:read "*a" -- *a or *all reads the whole file
    file:close()
    return content
end

local function WriteFile(path, content)
    local file = io.open(path, "wb") -- w write mode and b binary mode
    if not file then
      return nil
    end
    file:write(content)
    file:close()
end

local function ReadOWFS(device, filename, UseCache)
	if (UseCache == false) then
		path = OWFS_PATH.."uncached/"
	else
		path = OWFS_PATH
	end

   value = ReadFile(string.format("%s/%s/%s", path, device, filename))
   if (value ~= nil) then
         return value
   else
		-- Check if hub is configured with uncorrect value
		fileContent = ReadFile(ONEWIRE_HUB_CONFIG_FILE)
		if (fileContent ~= ONEWIRE_HUB_PORT_CONFIG_VALUE) then
			WriteFile(ONEWIRE_HUB_CONFIG_FILE, ONEWIRE_HUB_PORT_CONFIG_VALUE)
			print("-------------------")
			print("Onewire hub reconfigured")
		end
	end
	return nil
end

-- calcDeHumidLevel calucates the RF level for a certain temperature
-- If the RF is higher then returned value, dehumidification shall be done
-- A safety margin of five percent is added
function calcDeHumidLevel(temp)
		local humidityThreshold
      if (temp < 0) then
			humidityThreshold = 100
		elseif (temp > 22) then
         humidityThreshold = 79 - 5
      else
         humidityThreshold = integer(-0.0015 * temp ^ 3+0.1193 * temp ^ 2 - 2.9878 * temp + 102.96) - 5

			if (humidityThreshold > 100) then
				humidityThreshold = 100
			elseif (humidityThreshold < 0) then
				humidityThreshold = 0
			end

		end

		return humidityThreshold
end


-- secsToClock return a string representing seconds as HH:MM:SS
function secsToClock(seconds)
   if ((seconds == 0) or (seconds == nil) ) then
      return "00:00:00"
   else
      days  = integer(seconds / (60 * 60 * 24))
      hours = integer((seconds - days * 60 * 60 * 24) / (60 * 60))
      mins  = integer((seconds - days * 60 * 60 * 24 - hours * 60 * 60) / 60)
      secs  = seconds - days * 60 * 60 * 24 - hours * 60 * 60 - mins * 60;

      if (days > 99) then
         return string.format("%03d:%02d:%02d:%02d (DDD:HH:MM:SS)", days, hours, mins, secs)
      elseif (days > 0) then
         return string.format("%02d:%02d:%02d:%02d (DD:HH:MM:SS)", days, hours, mins, secs)
      else
         return string.format("%02d:%02d:%02d (HH:MM:SS)", hours, mins, secs)
      end
   end
end

-- Implode a string into a table using delimiter
function ImplodeTable(delimiter, list)
  local len = #list
  if len == 0 then
    return ""
  end
  local string = list[1]
  for i = 2, len do
    string = string .. delimiter .. list[i]
  end
  return string
end

-- Explode a table content into a string, separate fields with a delimiter
function ExplodeTable(delimiter, text, numElements)
   local list = {}; local pos = 1
   local el = 0
   while (el < numElements) do
      el = el + 1
      local first, last = string.find(text, delimiter, pos)
      if (first) then
         table.insert(list, string.sub(text, pos, first-1))
         pos = last+1
      else
         table.insert(list, string.sub(text, pos))
      break
      end
   end
   return list
end

-- Get the mean value of a table
function CalcMeanOnTable(t)
   local sum = 0
   local count= 0
   for k,v in pairs(t) do
      if (type(v) ~= 'number') then
         v = tonumber(v)
      end
      if (type(v) == 'number') then
         sum = sum + v
         count = count + 1
      end
  end
  return (sum/count)
end

-- Get the standard deviation of a table
function CalcStandardDeviationOnTable(t)
   local m
   local vm
   local sum = 0
   local count = 0
   local result

   m = CalcMeanOnTable(t)

   for k,v in pairs(t) do
      if (type(v) ~= 'number') then
         v = tonumber(v)
      end
      if (type(v) == 'number') then
         vm = v - m
         sum = sum + (vm * vm)
         count = count + 1
      end
   end

   return math.sqrt(sum / (count-1))
end


-- Calulates values from OWFS taking care of spikes in OWFS values.
-- Using an file buffer and calculation of mean and standard deviation.
-- If the value to be inserted deviates more than the standard deviation from mean value,
-- the standard deviation from the mean value from the buffer is returned instead of the actual value.
-- The actual value is stored in buffer

function getValue(device, value)
   local cache, arr, mean, deviation, allowedDeviation, newValue, elementsInBuffer

   -- Read history from cached file content
   cache = ReadFile(string.format("%s/%s", OWFS_CACHEPATH, device))

   -- If no file found
   if (cache == nil) then
      cache = ";"
   end

   -- Explode the file content into array elements
   arr = ExplodeTable(";", cache, OWFS_BUFFERSIZE)

   -- Calculate
   deviation = tonumber(CalcStandardDeviationOnTable(arr))
   mean      = tonumber(CalcMeanOnTable(arr))

   -- The allowed deviation shall not be too small
   if (deviation < 0.75) then
      allowedDeviation = 0.75
   else
      allowedDeviation = deviation
   end

   -- Limit the changes in the buffer
   if (value > (mean + allowedDeviation)) then
      newValue = mean + allowedDeviation
   elseif (value < (mean - allowedDeviation)) then
      newValue = mean - allowedDeviation
   else
      newValue = value
   end

   -- Insert calulated value last in buffer
   table.insert(arr, newValue)

   elementsInBuffer = # arr

   -- Remove values in front of buffer if buffer size is too big
   if ((elementsInBuffer) > OWFS_BUFFERSIZE) then
      table.remove(arr,1)
      elementsInBuffer = elementsInBuffer - 1
   end

   -- Write the array into file
   WriteFile(string.format("%s/%s", OWFS_CACHEPATH, device), ImplodeTable(";", arr))

   return elementsInBuffer, deviation, mean, tonumber(CalcMeanOnTable(arr))
end

-- END OF FUNCTIONS --

commandArray = {}

i = 0
for OWFS_device, name in pairs(OWFS_TEMP_HUM_DEVICES) do

   -- Read temp and humidity from OWFS
   OWFS_temp = ReadOWFS(OWFS_device, "temperature", false)
   OWFS_hum  = ReadOWFS(OWFS_device, "humidity", false)

   if ((OWFS_temp ~= nil) and (OWFS_hum ~= nil)) then

      OWFS_temp = tonumber(OWFS_temp)
      OWFS_hum  = tonumber(OWFS_hum)

      -- Correct OWFS value
      bufferSize, deviationTemp, meanTemp, tempValue = getValue(string.format("%s_%s", name, "temp"), OWFS_temp)

      print(string.format("%s:temp Bufsize = %3d, Deviation = %-3.2f, Mean = %-3.2f, OWFS =  %-3.2f, Used = %-3.2f, Diff = %-3.2f", name, bufferSize, deviationTemp, meanTemp, OWFS_temp, tempValue, math.abs(OWFS_temp - tempValue)))

      -- Correct OWFS value
      bufferSize, deviationHum, meanHum, humValue = getValue(string.format("%s_%s", name, "hum"), OWFS_hum)

      print(string.format("%s:humi Bufsize = %3d, Deviation = %-3.2f, Mean = %-3.2f, OWFS =  %-3.2f, Used = %-3.2f, Diff = %-3.2f", name, bufferSize, deviationHum, meanHum, OWFS_hum, humValue, math.abs(OWFS_hum - humValue)))

      -- Calculate the wet level
      startDehumidify = calcDeHumidLevel(tempValue)
      if (humValue > startDehumidify) then
         wet = 3
      elseif (humValue > startDehumidify * 0.8) then
         wet = 0
      else
         wet = 2
      end

      -- Insert values into Domoticz device
		if (otherdevices_idx[name] ~= nil) then
			commandArray[i] = { ['UpdateDevice'] = string.format("%s|0|%3.2f;%3.2f;%d", otherdevices_idx[name], tempValue, humValue, wet) }
			i = i + 1
		else
			print(string.format("Cannot find id number for device %s", name))
		end
   else
      print(string.format("No OWFS readings from device %s, %s: %s:%s", name, OWFS_device, OWFS_temp, OWFS_hum))
   end
end
for OWFS_device, name in pairs(OWFS_TEMP_DEVICES) do

   -- Read temp and humidity from OWFS
   OWFS_temp = ReadOWFS(OWFS_device, "temperature", true)

   if (OWFS_temp ~= nil) then

      OWFS_temp = tonumber(OWFS_temp)
      print(string.format("%s: temp = %3.2f", name, OWFS_temp))

      -- Insert values into Domoticz device
		if (otherdevices_idx[name] ~= nil) then
			commandArray[i] = { ['UpdateDevice'] = string.format("%s|0|%3.2f", otherdevices_idx[name], OWFS_temp) }
			i = i + 1
		else
			print(string.format("Cannot find id number for device %s", name))
		end
   else
      print(string.format("No OWFS readings from device %s, %s: %s:%s", name, OWFS_device, OWFS_temp, OWFS_hum))
   end
end

return commandArray