void OnReceiveMessage(MqttApplicationMessage e)
{
Log.Instance.Debug($"Received MQTT message on topic {e.Topic}");
// todo: add some validation to ensure the message is proper
if (e.Topic.StartsWith("pair"))
{
// read json to get identifier
var data = JObject.Parse(Encoding.UTF8.GetString(e.Payload));
UserIdentifier = data["data"].ToObject <string>();
// save settings for future use
Configuration.Set("user_identifier", UserIdentifier);
Configuration.Save();
// subscribe to messages
Log.Instance.Info($"Subscribing to events for user identifier {UserIdentifier}");
MQTTClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(
string.IsNullOrWhiteSpace(TopicPrefix) ? $"{UserIdentifier}/event" : $"{TopicPrefix}/{UserIdentifier}/event"
).Build());
State = MQTTMessageState.Listening;
}
else if (e.Topic.StartsWith(UserIdentifier))
{
var data = Encoding.UTF8.GetString(e.Payload);
RouteMessage(JsonMessage.Parse(data));
}
else
{
Log.Instance.Warning("Unexpected MQTT message");
}
}
// presently this is only configured to connect to MQTT over secure websockets
public async void Initialize(string server, string username = null, string password = null)
{
// configure client
var factory = new MqttFactory();
MQTTClient = factory.CreateMqttClient();
// load server config -- currently exoects MQTT over secure websockets
var options = new MqttClientOptionsBuilder()
.WithWebSocketServer(server)
.WithTls();
// add authentication options if applicable
if (!string.IsNullOrWhiteSpace(username))
{
options = options.WithCredentials(username, password);
}
// setup handlers to add after connecting
MQTTClient.UseConnectedHandler(async e => {
Log.Instance.Debug("Connected to MQTT server");
if (!string.IsNullOrWhiteSpace(UserIdentifier))
{
Log.Instance.Info($"Subscribing to events for user identifier {UserIdentifier}");
await MQTTClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(
string.IsNullOrWhiteSpace(TopicPrefix) ? $"{UserIdentifier}/event" : $"{TopicPrefix}/{UserIdentifier}/event"
).Build());
State = MQTTMessageState.Listening;
}
else
{
Log.Instance.Info($"No user identifier provided; subscribing to pairing events with pairing key {PairingKey}");
await MQTTClient.SubscribeAsync(new TopicFilterBuilder().WithTopic(
string.IsNullOrWhiteSpace(TopicPrefix) ? $"pair/{PairingKey}" : $"{TopicPrefix}/pair/{PairingKey}"
).Build());
State = MQTTMessageState.Pairing;
}
});
// add handler
MQTTClient.UseApplicationMessageReceivedHandler(e => { OnReceiveMessage(e.ApplicationMessage); });
// connect
await MQTTClient.ConnectAsync(options.Build(), CancellationToken.None);
}
public MQTTMessageProvider(ISimulator Simulator) : base(Simulator)
{
State = MQTTMessageState.Offline;
PairingKey = NNumber.Generate();
}
