From bdc5548ec21c5b2c0272935af0776b455d0e7fd4 Mon Sep 17 00:00:00 2001
From: Chris Kaczor <chris@kaczorzoo.net>
Date: Sat, 13 Jan 2024 22:30:06 -0500
Subject: [PATCH] Add SignalR for environment service

---
 Environment/Service/MessageHandler.cs         | 34 +++++++++++++++++--
 Environment/Service/Service.csproj            |  1 +
 .../Service/appsettings.Development.json      |  4 +++
 Environment/Service/appsettings.json          |  3 ++
 4 files changed, 39 insertions(+), 3 deletions(-)

diff --git a/Environment/Service/MessageHandler.cs b/Environment/Service/MessageHandler.cs
index 61dabcc..29e361d 100644
--- a/Environment/Service/MessageHandler.cs
+++ b/Environment/Service/MessageHandler.cs
@@ -2,6 +2,8 @@
 using ChrisKaczor.HomeMonitor.Environment.Service.Data;
 using MQTTnet;
 using MQTTnet.Client;
+using Microsoft.AspNetCore.SignalR.Client;
+using System.Threading;
 
 namespace ChrisKaczor.HomeMonitor.Environment.Service;
 
@@ -10,6 +12,7 @@ public class MessageHandler : IHostedService
     private readonly IConfiguration _configuration;
     private readonly Database _database;
     private readonly IMqttClient _mqttClient;
+    private HubConnection _hubConnection;
 
     private readonly MqttFactory _mqttFactory;
     private readonly string _topic;
@@ -30,20 +33,26 @@ public class MessageHandler : IHostedService
         _mqttClient = _mqttFactory.CreateMqttClient();
 
         _mqttClient.ApplicationMessageReceivedAsync += OnApplicationMessageReceivedAsync;
+
+        _hubConnection = new HubConnectionBuilder().WithUrl(configuration["Environment:Hub:Url"] ?? string.Empty).Build();
     }
 
     public async Task StartAsync(CancellationToken cancellationToken)
     {
+        await _hubConnection.StartAsync(cancellationToken);
+
         var mqttClientOptions = new MqttClientOptionsBuilder().WithTcpServer(_configuration["Mqtt:Server"]).Build();
-        await _mqttClient.ConnectAsync(mqttClientOptions, CancellationToken.None);
+        await _mqttClient.ConnectAsync(mqttClientOptions, cancellationToken);
 
         var mqttSubscribeOptions = _mqttFactory.CreateSubscribeOptionsBuilder().WithTopicFilter($"{_topic}/#").Build();
-        await _mqttClient.SubscribeAsync(mqttSubscribeOptions, CancellationToken.None);
+        await _mqttClient.SubscribeAsync(mqttSubscribeOptions, cancellationToken);
     }
 
     public async Task StopAsync(CancellationToken cancellationToken)
     {
-        await _mqttClient.DisconnectAsync(new MqttClientDisconnectOptionsBuilder().Build(), CancellationToken.None);
+        await _mqttClient.DisconnectAsync(new MqttClientDisconnectOptionsBuilder().Build(), cancellationToken);
+
+        await _hubConnection.StopAsync(cancellationToken);
     }
 
     private async Task OnApplicationMessageReceivedAsync(MqttApplicationMessageReceivedEventArgs arg)
@@ -59,6 +68,25 @@ public class MessageHandler : IHostedService
             return;
 
         await _database.StoreMessageAsync(message);
+
+        await SendLatestReading(message);
+    }
+
+    private async Task SendLatestReading(Message message)
+    {
+        try
+        {
+            if (_hubConnection.State == HubConnectionState.Disconnected)
+                await _hubConnection.StartAsync();
+
+            var json = JsonSerializer.Serialize(message);
+
+            await _hubConnection.InvokeAsync("SendLatestReading", json);
+        }
+        catch (Exception exception)
+        {
+            WriteLog($"Hub exception: {exception}");
+        }
     }
 
     private static void WriteLog(string message)
diff --git a/Environment/Service/Service.csproj b/Environment/Service/Service.csproj
index 1d3735f..0729f44 100644
--- a/Environment/Service/Service.csproj
+++ b/Environment/Service/Service.csproj
@@ -23,6 +23,7 @@
     <PackageReference Include="Dapper" Version="2.1.28" />
     <PackageReference Include="dbup-sqlserver" Version="5.0.37" />
     <PackageReference Include="JetBrains.Annotations" Version="2023.3.0" />
+    <PackageReference Include="Microsoft.AspNetCore.SignalR.Client" Version="8.0.1" />
     <PackageReference Include="MQTTnet.AspNetCore" Version="4.3.3.952" />
   </ItemGroup>
 
diff --git a/Environment/Service/appsettings.Development.json b/Environment/Service/appsettings.Development.json
index 196c711..b51e18b 100644
--- a/Environment/Service/appsettings.Development.json
+++ b/Environment/Service/appsettings.Development.json
@@ -13,8 +13,12 @@
             "Host": "localhost",
             "User": "sa",
             "Password": "newpassword",
+            "Port": 1433,
             "Name": "Environment",
             "TrustServerCertificate": true
+        },
+        "Hub": {
+            "Url": "http://localhost:8080/environment"
         }
     }
 }
diff --git a/Environment/Service/appsettings.json b/Environment/Service/appsettings.json
index 5daebe4..4826422 100644
--- a/Environment/Service/appsettings.json
+++ b/Environment/Service/appsettings.json
@@ -18,6 +18,9 @@
             "Name": "Environment",
             "TrustServerCertificate": true,
             "Port": 1435
+        },
+        "Hub": {
+            "Url": "http://hub-server/environment"
         }
     }
 }