shgxtzcjhoudaosaomadayinwpf/RIZO_Application/Modules/RIZO_Application.Modules.ModuleName/ViewModels/MqttControlViewModel.cs

using System;
using System.Collections.Generic;
using System.Text.Json;
using System.Threading.Tasks;
using System.Windows;
using MQTTnet.Client;
using Prism.Events;
using Prism.Regions;
using RIZO_Application.Core;
using RIZO_Application.Core.Mvvm;
using RIZO_Application.Infrastructure.Model;
using RIZO_Helper.Tools;

namespace RIZO_Application.Modules.ModuleName.ViewModels
{
    public class MqttControlViewModel : RegionViewModelBase
    {
        private readonly IEventAggregator _eventAggregator;
        private MqttHelper? _mqttHelper;
        private SubscriptionToken _token;
        
        public MqttControlViewModel(
            IRegionManager regionManager,
            IEventAggregator eventAggregator)
            : base(regionManager)
        {
            _eventAggregator = eventAggregator;
            _token = _eventAggregator.GetEvent<ScanEvent>().Subscribe(OnScanEventReceived, ThreadOption.UIThread, true);
            InitializeMqttAsync().ConfigureAwait(false);
        }

        private async Task InitializeMqttAsync()
        {
            try
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"Mqtt初始化……");

                string serverUrl = GetMqttConfigValue(MqttConfigs.Current?.ServerUrl);
                string clientId = GetMqttConfigValue(MqttConfigs.Current?.ClientId) + Guid.NewGuid().ToString("N");

                _mqttHelper = new MqttHelper(serverUrl, 1883, clientId);
                _mqttHelper.MessageReceived += HandleMqttMessage;
                _mqttHelper.ConnectionFailed += HandleMqttConnectionFailed;
                _mqttHelper.Disconnected += Publish;
                if (await ConnectMqttAsync())
                {
                    await SubscribeToTopicsAsync();
                    await PublishInitialMessageAsync();
                }

                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"Mqtt初始化完成");
            }
            catch (Exception ex)
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"Mqtt初始化失败: {ex.Message}");
            }
        }

        private string GetMqttConfigValue(string? configValue)
        {
            return configValue ?? "noConfig";
        }

        private async Task<bool> ConnectMqttAsync()
        {
            if (_mqttHelper == null) return false;

            bool isConnected = await _mqttHelper.ConnectAsync();
            if (!isConnected)
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"MQTT连接失败");
            }
            return isConnected;
        }

        private async Task SubscribeToTopicsAsync()
        {
            if (_mqttHelper == null || MqttConfigs.Current == null || SiteConfigs.Current == null) return;

            string printTopic = $"{MqttConfigs.Current.Topic}/print/{SiteConfigs.Current.SiteName}";
            if (await _mqttHelper.SubscribeAsync(printTopic))
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"订阅:{printTopic}");
            }
            
        }

        private async Task PublishInitialMessageAsync()
        {
            if (_mqttHelper == null || MqttConfigs.Current == null || SiteConfigs.Current == null) return;

            string connectTopic = $"{MqttConfigs.Current.Topic}/connect/{SiteConfigs.Current.SiteName}";
            if (await _mqttHelper.PublishAsync(connectTopic, "已连接"))
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"发布连接消息到: {connectTopic}");
            }
        }

        public void HandleMqttMessage(object sender, MqttApplicationMessageReceivedEventArgs e)
        {
            try
            {
                string topic = e.ApplicationMessage.Topic;
                string payload = System.Text.Encoding.UTF8.GetString(e.ApplicationMessage.Payload);
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"收到信息'{topic}': {payload}");

                if (MqttConfigs.Current == null || SiteConfigs.Current == null) return;
                // 处理mqtt打印消息
                if (topic == $"{MqttConfigs.Current.Topic}/print/{SiteConfigs.Current.SiteName}")
                {
                    var printMessage = ParsePrintMessage(payload);
                    if (printMessage != null)
                    {
                        _eventAggregator.GetEvent<PrintEvent>().Publish(printMessage);
                    }
                }
            }
            catch (Exception ex)
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"处理MQTT消息时出错: {ex.Message}");
            }
        }

        private PrintDto? ParsePrintMessage(string payload)
        {
            try
            {
                var jsonData = JsonSerializer.Deserialize<PrintDto>(payload);
                return jsonData;
            }
            catch (JsonException ex)
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"JSON 解析错误: {ex.Message}");
                return null;
            }
        }

        private void HandleMqttConnectionFailed(object sender, Exception ex)
        {
            _eventAggregator.GetEvent<SystemLogEvent>().Publish($"MQTT连接失败: {ex.Message}");
        }

        private async void OnScanEventReceived(string message)
        {
            if (_mqttHelper == null || MqttConfigs.Current == null || SiteConfigs.Current == null || SerialConfigs.Current == null) return;

            try
            {
                var jsonObject = new
                {
                    SiteNo = SiteConfigs.Current.SiteName,
                    ComNo = SerialConfigs.Current.ComName,
                    Time = DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"),
                    LabelCode = message
                };

                string jsonMessage = JsonSerializer.Serialize(jsonObject);
                string topic = $"{MqttConfigs.Current.Topic}/SiteComLabelCode";

                if (await _mqttHelper.PublishAsync(topic, jsonMessage))
                {
                    _eventAggregator.GetEvent<SystemLogEvent>().Publish($"发布扫描消息到: {topic}");
                }
            }
            catch (Exception ex)
            {
                _eventAggregator.GetEvent<SystemLogEvent>().Publish($"发布扫描消息时出错: {ex.Message}");
            }
        }
        public void Publish(string message, int retries, int maxRetries)
        {
            _eventAggregator.GetEvent<SystemLogEvent>().Publish(message);
            if (retries>=maxRetries)
            {
                MessageBox.Show("MQTT服务器已掉线，请停止扫码并重启系统");
            }
        }
        public async void Destroy()
        {
            _token?.Dispose();

            if (_mqttHelper != null)
            {
                await _mqttHelper.DisconnectAsync();
                _mqttHelper.Dispose();
            }
        }
    }
}