Agent-Device Communications

comms.agent.nut

// Agent Globals

locationLong <- 999
locationLat <- 999
dummyValue <- 0


// Weather functions

function getForecast()
{
	local apikey = "YOUR API KEY HERE"
	local request = http.get("https://api.forecast.io/forecast/" + apikey + "/" + locationLong.tostring() + "," + locationLat.tostring())
	request.sendasync(forecastHandler)
}

function forecastHandler(response)
{
	// Decode the JSON (error thrown if invalid)
		
	local forecast = http.jsondecode(a_response.body)
 
	if ("hourly" in forecast) 
	{
      		if ("data" in forecast.hourly)
      		{
            		// Get second item in array: weather one hour hence
            
            		local weather = forecast.hourly.data[1]
            		device.send("set.forecast", weather.icon)
            	}
	}
}

// Location determination functions

function addColons(bssid)
{
	local result = bssid.slice(0, 2)
	
	for (local i = 2 ; i < 12 ; i += 2)
	{
		result += ":" + bssid.slice(i, (i + 2))
	}
	
	return result
}

function getLocation(networks)
{
	// Passes the results of the device's WiFi scan to Google to triangulate the device's location
	
	local url = "https://maps.googleapis.com/maps/api/browserlocation/json?browser=electric-imp&sensor=false"
	
	foreach (network in networks) 
	{
		url += ("&wifi=mac:" + addColons(network.bssid) + "|ss:" + network.rssi)
	}

    if (url.len() > 356) url.slice(0, 356)
	local request = http.get(url)
	local response = request.sendsync()
    
    if (response.statuscode == 200) 
	{
		local data = http.jsondecode(response.body)
		if ("location" in data)
		{
		    locationLat = data.location.lat
		    locationLong = data.location.lng
		}
		
		// Now we have a location, check the weather
		// Note: this is function is omitted for clarity, but
		// it is envisaged that it returns a value representing
		// the next hour's weather
		
		forecast = getForecast()
	}
}

function locationLookup(dummy)
{
	// This message triggers an action on the part of the device but
	// we still need to send a value (even though it will be ignored) 
	
	if (locationLong == 999 && locationLat == 999)
	{
		device.send("get.networks", dummyValue)
	}
	else
	{
		getForecast()
	}
}


// Register device event triggers

device.on("get.forecast", locationLookup)
device.on("set.location", getLocation)