public SsmlOutputSpeech HandleNearbyAircraftIntent(IntentRequest intentRequest)
{
// build the speech response
var speech = new Alexa.NET.Response.SsmlOutputSpeech();
Slot distanceSlot = null;
Slot distanceUnitsSlot = null;
intentRequest.Intent.Slots?.TryGetValue("distance", out distanceSlot);
intentRequest.Intent.Slots?.TryGetValue("distanceUnits", out distanceUnitsSlot);
double distanceValue = distanceSlot != null?Convert.ToDouble(distanceSlot.Value) : 20;
string distanceUnitsValue = distanceUnitsSlot != null ? distanceUnitsSlot.Value : "kilometres";
var distance = Distance.FromKilometres(distanceValue);
var location = new GeoLocation(52.041808, 1.208131);
var north = GeoLocation.FindPointAtDistanceFrom(location, Angle.FromDegrees(0), distance);
var south = GeoLocation.FindPointAtDistanceFrom(location, Angle.FromDegrees(180), distance);
var east = GeoLocation.FindPointAtDistanceFrom(location, Angle.FromDegrees(90), distance);
var west = GeoLocation.FindPointAtDistanceFrom(location, Angle.FromDegrees(270), distance);
var flights = FlightRadar24.GetFlights(north.Latitude, south.Latitude, east.Longitude, west.Longitude);
if (flights == null)
{
speech.Ssml = "I'm unable to contact Flight Radar.";
return(speech);
}
var withinRangeOrderedByClosest = (from sighting in flights.Sightings
let d = GeoLocation.DistanceBetween(sighting.Location, location)
where d.Kilometres < distance.Kilometres
orderby d.Kilometres descending
select new { sighting, d }).ToArray();
if (withinRangeOrderedByClosest.Length == 0)
{
speech.Ssml = "There are no flights within {distanceValue} {distanceUnitsValue}.";
return(speech);
}
var closest = withinRangeOrderedByClosest.First();
var bearing = GeoLocation.RhumbBearing(location, closest.sighting.Location).Degrees;
var id = AddIndefiniteArticle(closest.sighting.AircraftType) + (closest.sighting.FlightNumber != null
? $", flight {closest.sighting.FlightNumber}"
: "");
var destination = closest.sighting.Arrving != null ? $"to {closest.sighting.Arrving}" : "";
var callsign = closest.sighting.CallSign != null? $"{closest.sighting.CallSign}":"";
speech.Ssml = $"<speak>There {GetIsOrAre(withinRangeOrderedByClosest.Length)} {withinRangeOrderedByClosest.Length} aircraft within {distanceValue:N0} {distanceUnitsValue}. The closest is {callsign} {destination}, range {closest.d.Kilometres:N0} kilometres, bearing {bearing:N0}, travelling at {closest.sighting.GroundSpeedKts} knots and altitude {Distance.FromFeet(closest.sighting.AltitudeFt).Metres:N0} metres.</speak>";
return(speech);
}