mycorerepository/MyCore/Extensions/MqttClientService.cs

using MQTTnet;
using MQTTnet.Client;
using MQTTnet.Client.Connecting;
using MQTTnet.Client.Disconnecting;
using MQTTnet.Client.Options;
using MyCore.Interfaces.Models;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Mqtt.Client.AspNetCore.Services
{
    public class MqttClientService : IMqttClientService
    {
        private static IMqttClient mqttClient;
        private IMqttClientOptions options;
        public static List<Zigbee2MqttDevice> devices = new List<Zigbee2MqttDevice>();


        public MqttClientService(IMqttClientOptions options)
        {
            this.options = options;
            this.options = new MqttClientOptionsBuilder()
                    .WithClientId("ApiService")
                    .WithTcpServer("192.168.31.140") // TODO replace by localhost
                    .WithCredentials("mqtt", "mqtt")
                    .WithCleanSession()
                    .Build();
            mqttClient = new MqttFactory().CreateMqttClient();
            ConfigureMqttClient();
        }

        private void ConfigureMqttClient()
        {
            mqttClient.ConnectedHandler = this;
            mqttClient.DisconnectedHandler = this;
            mqttClient.ApplicationMessageReceivedHandler = this;
        }

        public Task HandleApplicationMessageReceivedAsync(MqttApplicationMessageReceivedEventArgs e)
        {
            Console.WriteLine("### RECEIVED APPLICATION MESSAGE ###");
            Console.WriteLine($"+ Topic = {e.ApplicationMessage.Topic}");
            var payload = "";
            if (e.ApplicationMessage.Payload != null)
            {
                Console.WriteLine($"+ Payload = {Encoding.UTF8.GetString(e.ApplicationMessage.Payload)}");
                payload = Encoding.UTF8.GetString(e.ApplicationMessage.Payload);
            }


            Console.WriteLine($"+ QoS = {e.ApplicationMessage.QualityOfServiceLevel}");
            Console.WriteLine($"+ Retain = {e.ApplicationMessage.Retain}");
            Console.WriteLine();

            var topic = e.ApplicationMessage.Topic;

            switch (topic)
            {
                case "zigbee2mqtt/bridge/config/devices":
                    try
                    {
                        var test = JsonConvert.DeserializeObject<List<Zigbee2MqttDevice>>(payload);
                        devices = test;

                        // TODO Update in DB, current devices state
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine($"Error during retrieving devices ! Exception: {ex}");
                    }
                    break;
            }

            //return new Task(null);
            // TODO check what to do
            //await PublishMessage("test", "teeest");
            return null;
        }

        public async Task HandleConnectedAsync(MqttClientConnectedEventArgs eventArgs)
        {
            System.Console.WriteLine("connected");
            //await mqttClient.SubscribeAsync("hello/world");
            await mqttClient.SubscribeAsync("#");
            await PublishMessage("zigbee2mqtt/bridge/config/devices/get", "");
        }

        public async Task HandleDisconnectedAsync(MqttClientDisconnectedEventArgs eventArgs)
        {
            if (!mqttClient.IsConnected)
            {
                await mqttClient.ReconnectAsync();
            }
            //throw new System.NotImplementedException();
        }

        public async Task StartAsync(CancellationToken cancellationToken)
        {
            await mqttClient.ConnectAsync(options);
            if (!mqttClient.IsConnected)
            {
                await mqttClient.ReconnectAsync();
            }
        }

        public async Task StopAsync(CancellationToken cancellationToken)
        {
            if(cancellationToken.IsCancellationRequested)
            {
                var disconnectOption = new MqttClientDisconnectOptions
                {
                    ReasonCode = MqttClientDisconnectReason.NormalDisconnection,
                    ReasonString = "NormalDiconnection"
                };
                await mqttClient.DisconnectAsync(disconnectOption, cancellationToken);
            }
            await mqttClient.DisconnectAsync();
        }

        public static async Task PublishMessage(string topic, string message)
        {
            var mqttMessage = new MqttApplicationMessageBuilder()
                .WithTopic(topic)
                .WithPayload(message)
                .WithExactlyOnceQoS()
                .WithRetainFlag()
                .Build();

            if (mqttClient.IsConnected)
                await mqttClient.PublishAsync(mqttMessage);
        }

        public static List<Zigbee2MqttDevice> GetDevices()
        {
            return devices;
        }
    }
}