agrobot_base/AgroBase/AgroBase/Services/MqttService.cs

using AgroBase.Forms;
using AgroBase.Models;
using AgroBase.Services;
using MQTTnet;
using MQTTnet.Client;
using MQTTnet.Client.Options;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

public class MqttService
{
    private IMqttClient _client;
    private IMqttClientOptions _options;
    private Timer tmrCheck = new Timer() { Interval = 1000 };

    public List<MqttTopicosModel> Topicos = new List<MqttTopicosModel>()
    {
        new MqttTopicosModel()
        {
            Topico = MapasVariaveisModel.TopicoCoordenadasGPS, 
            Mensagens = new List<MqttTopicosMensagensModel>(), 
            Inscrever = false
        }, 
        new MqttTopicosModel()
        {
            Topico = MapasVariaveisModel.TopicoSelecaoRuasMapa, 
            Mensagens = new List < MqttTopicosMensagensModel>(), 
            Inscrever = true
        },
        new MqttTopicosModel()
        {
            Topico = MapasVariaveisModel.TopicoTrajetoriaDinamica,
            Mensagens = new List<MqttTopicosMensagensModel>(),
            Inscrever = false
        },
    };

    public MqttService(string brokerAddress, int brokerPort)
    {
        var factory = new MqttFactory();
        _client = factory.CreateMqttClient();

        _options = new MqttClientOptionsBuilder()
            .WithTcpServer(brokerAddress, brokerPort)
            .WithCleanSession()
            .Build();

        _client.UseConnectedHandler(async e =>
        {
            Console.WriteLine("Connected to MQTT Broker.");
            // Exemplo de inscrição em um tópico
            foreach (var topic in Topicos)
            {
                await SubscribeAsync(topic);
            }
        });

        _client.UseDisconnectedHandler(e =>
        {
            Console.WriteLine("Disconnected from MQTT Broker.");
        });

        _client.UseApplicationMessageReceivedHandler(e =>
        {
            string message = Encoding.UTF8.GetString(e.ApplicationMessage.Payload);
            //Console.WriteLine($"Message received on topic {e.ApplicationMessage.Topic}");
            // Aqui você pode adicionar o código para lidar com a mensagem recebida

            var topico = Topicos.FirstOrDefault(x => x.Topico == e.ApplicationMessage.Topic);
            if (topico != null)
            {
                topico.Mensagens.Add(new MqttTopicosMensagensModel()
                {
                    Momento = DateTime.Now,
                    Cliente = e.ClientId,
                    Mensagem = message
                });

                if (topico.Topico == MapasVariaveisModel.TopicoSelecaoRuasMapa)
                {
                    Variaveis.OperacaoEmAndamento.OpMapaGPS.AtualizarRuasSelecionadas();
                }
            }
        });

        tmrCheck.Tick += TmrCheck_Tick;
        tmrCheck.Start();
    }

    private void TmrCheck_Tick(object sender, EventArgs e)
    {
        if (!_client.IsConnected)
        {
            ConnectAsync().ConfigureAwait(false);
        }
        frmInstancial.frmPrincipal.lblStripMqtt.Text = "MQTT: " + (_client.IsConnected ? "Conectado" : "Desconectado");
    }

    public bool StatusConexao()
    {
        return _client.IsConnected;
    }

    public async Task ConnectAsync()
    {
        try
        {
            await _client.ConnectAsync(_options);
        }
        catch (Exception ex)
        {
            Console.WriteLine("Erro ao tentar se conectar ao MQTT Broker: " + ex.Message);
        }
    }

    public async Task DisconnectAsync()
    {
        await _client.DisconnectAsync();
    }

    public async Task PublishAsync(MqttTopicosModel topic, string message, bool Forcar = false)
    {
        if (topic.Inscrever && !Forcar)
        {
            return;
        }

        var payload = Encoding.UTF8.GetBytes(message);
        var mqttMessage = new MqttApplicationMessageBuilder()
            .WithTopic(topic.Topico)
            .WithPayload(payload)
            .Build();

        await _client.PublishAsync(mqttMessage);
    }

    public async Task SubscribeAsync(MqttTopicosModel topic)
    {
        if (!topic.Inscrever)
        {
            return;
        }
        try
        {
            if (!_client.IsConnected)
            {
                await ConnectAsync();
            }
            await _client.SubscribeAsync(new TopicFilterBuilder().WithTopic(topic.Topico).Build());
            Console.WriteLine("Subscribed to topic: " + topic.Topico);
        }
        catch (Exception ex)
        {
            Console.WriteLine($"An error occurred while subscribing from the topic: {ex.Message}");
        }
    }

    public async Task UnsubscribeAsync(MqttTopicosModel topic)
    {
        if (topic == null || !topic.Inscrever)
        {
            return;
        }
        try
        {
            if (!_client.IsConnected)
            {
                await ConnectAsync();
            }
            await _client.UnsubscribeAsync(new string[] { topic.Topico });
            Console.WriteLine("Unsubscribed from topic: " + topic.Topico);
        }
        catch (Exception ex)
        {
            Console.WriteLine($"An error occurred while unsubscribing from the topic: {ex.Message}");
        }
    }


    public class MqttTopicosModel
    {
        public string Topico { get; set; }
        public List<MqttTopicosMensagensModel> Mensagens { get; set; }
        public bool Inscrever { get; set; }
    }

    public class MqttTopicosMensagensModel
    {
        public DateTime Momento { get; set; }
        public string Cliente { get; set; }
        public string Mensagem { get; set; }
    }
}