/// <summary>
/// Adds the disconnected handler and the reconnect functionality to the client.
/// </summary>
/// <param name="options">The configuration option.</param>
private void AddDisconnectedHandler(SparkplugDeviceOptions options)
{
this.Client.UseDisconnectedHandler(
async e =>
{
// Wait until the disconnect interval is reached
await Task.Delay(options.ReconnectInterval);
// Connect, subscribe to incoming messages and send a state message
await this.ConnectInternal(options);
await this.SubscribeInternal(options);
await this.PublishInternal(options);
});
}
/// <summary>
/// Loads the messages used by the the Sparkplug device.
/// </summary>
/// <param name="options">The configuration option.</param>
private void LoadMessages(SparkplugDeviceOptions options)
{
this.willMessage = this.MessageGenerator.CreateSparkplugMessage(
this.NameSpace,
options.GroupIdentifier,
SparkplugMessageType.DeviceDeath,
options.EdgeNodeIdentifier,
options.DeviceIdentifier);
this.deviceOnlineMessage = this.MessageGenerator.CreateSparkplugMessage(
this.NameSpace,
options.GroupIdentifier,
SparkplugMessageType.DeviceBirth,
options.EdgeNodeIdentifier,
null);
}
/// <summary>
/// Starts the Sparkplug device.
/// </summary>
/// <param name="options">The configuration option.</param>
/// <returns>A <see cref="Task"/> representing any asynchronous operation.</returns>
public async Task Start(SparkplugDeviceOptions options)
{
// Load messages
this.LoadMessages(options);
// Add handlers
this.AddDisconnectedHandler(options);
this.AddMessageReceivedHandler();
// Connect, subscribe to incoming messages and send a state message
await this.ConnectInternal(options);
await this.SubscribeInternal(options);
await this.PublishInternal(options);
}
/// <summary>
/// Connects the Sparkplug device to the MQTT broker.
/// </summary>
/// <param name="options">The configuration option.</param>
/// <returns>A <see cref="Task"/> representing any asynchronous operation.</returns>
private async Task ConnectInternal(SparkplugDeviceOptions options)
{
options.CancellationToken ??= CancellationToken.None;
var builder = new MqttClientOptionsBuilder()
.WithClientId(options.ClientId)
.WithCredentials(options.UserName, options.Password)
.WithCleanSession(false)
.WithProtocolVersion(MqttProtocolVersion.V311);
if (options.UseTls)
{
builder.WithTls();
}
if (options.WebSocketParameters is null)
{
builder.WithTcpServer(options.BrokerAddress, options.Port);
}
else
{
builder.WithWebSocketServer(options.BrokerAddress, options.WebSocketParameters);
}
if (options.ProxyOptions != null)
{
builder.WithProxy(
options.ProxyOptions.Address,
options.ProxyOptions.Username,
options.ProxyOptions.Password,
options.ProxyOptions.Domain,
options.ProxyOptions.BypassOnLocal);
}
if (this.willMessage != null)
{
builder.WithWillMessage(this.willMessage);
}
this.ClientOptions = builder.Build();
await this.Client.ConnectAsync(this.ClientOptions, options.CancellationToken.Value);
}
/// <summary>
/// Subscribes the client to the device subscribe topic.
/// </summary>
/// <param name="options">The configuration option.</param>
/// <returns>A <see cref="Task"/> representing any asynchronous operation.</returns>
private async Task SubscribeInternal(SparkplugDeviceOptions options)
{
var deviceCommandSubscribeTopic = this.TopicGenerator.GetDeviceCommandSubscribeTopic(this.NameSpace, options.GroupIdentifier, options.EdgeNodeIdentifier, options.DeviceIdentifier);
await this.Client.SubscribeAsync(deviceCommandSubscribeTopic, MqttQualityOfServiceLevel.AtLeastOnce);
}
/// <summary>
/// Publishes data to the MQTT broker.
/// </summary>
/// <param name="options">The configuration option.</param>
/// <returns>A <see cref="Task"/> representing any asynchronous operation.</returns>
private async Task PublishInternal(SparkplugDeviceOptions options)
{
options.CancellationToken ??= CancellationToken.None;
await this.Client.PublishAsync(this.deviceOnlineMessage, options.CancellationToken.Value);
}