Convert serial reader from console to web API

Weather/SerialReader/SerialReader.cs

@@ -0,0 +1,170 @@
+using ChrisKaczor.HomeMonitor.Weather.Models;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Hosting;
+using Newtonsoft.Json;
+using RabbitMQ.Client;
+using System;
+using System.IO.Ports;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace ChrisKaczor.HomeMonitor.Weather.SerialReader
+{
+    public class SerialReader : IHostedService
+    {
+        private readonly IConfiguration _configuration;
+
+        public static bool BoardStarted { get; private set; }
+        public static DateTimeOffset LastReading { get; private set; }
+
+        private CancellationToken _cancellationToken;
+
+        public SerialReader(IConfiguration configuration)
+        {
+            _configuration = configuration;
+        }
+
+        public Task StartAsync(CancellationToken cancellationToken)
+        {
+            _cancellationToken = cancellationToken;
+
+            Task.Run(Execute, cancellationToken);
+
+            return Task.CompletedTask;
+        }
+
+        private void Execute()
+        {
+            var baudRate = int.Parse(_configuration["Weather:Port:BaudRate"]);
+
+            while (!_cancellationToken.IsCancellationRequested)
+            {
+                try
+                {
+                    WriteLog("Starting main loop");
+
+                    Thread.Sleep(1000);
+
+                    var port = GetPort();
+
+                    if (port == null)
+                        continue;
+
+                    using var serialPort = new SerialPort(port, baudRate) { NewLine = "\r\n" };
+
+                    WriteLog("Opening serial port");
+
+                    serialPort.Open();
+
+                    BoardStarted = false;
+
+                    var factory = new ConnectionFactory
+                    {
+                        HostName = _configuration["Weather:Queue:Host"],
+                        UserName = _configuration["Weather:Queue:User"],
+                        Password = _configuration["Weather:Queue:Password"]
+                    };
+
+                    WriteLog("Connecting to queue server");
+
+                    using var connection = factory.CreateConnection();
+                    using var model = connection.CreateModel();
+
+                    WriteLog("Declaring queue");
+
+                    model.QueueDeclare(_configuration["Weather:Queue:Name"], true, false, false, null);
+
+                    WriteLog("Starting serial read loop");
+
+                    ReadSerial(serialPort, model);
+                }
+                catch (Exception exception)
+                {
+                    WriteLog($"Exception: {exception}");
+                }
+            }
+        }
+
+        private void ReadSerial(SerialPort serialPort, IModel model)
+        {
+            while (!_cancellationToken.IsCancellationRequested)
+            {
+                try
+                {
+                    var message = serialPort.ReadLine();
+
+                    if (!BoardStarted)
+                    {
+                        BoardStarted = message.Contains("Board started");
+
+                        if (BoardStarted)
+                            WriteLog("Board started");
+                    }
+
+                    if (!BoardStarted)
+                    {
+                        WriteLog($"Message received but board not started: {message}");
+                        continue;
+                    }
+
+                    LastReading = DateTimeOffset.UtcNow;
+
+                    WriteLog($"Message received: {message}");
+
+                    var weatherMessage = WeatherMessage.Parse(message);
+
+                    var messageString = JsonConvert.SerializeObject(weatherMessage);
+
+                    var body = Encoding.UTF8.GetBytes(messageString);
+
+                    var properties = model.CreateBasicProperties();
+
+                    properties.Persistent = true;
+
+                    model.BasicPublish(string.Empty, _configuration["Weather:Queue:Name"], properties, body);
+                }
+                catch (TimeoutException)
+                {
+                    WriteLog("Serial port read timeout");
+                }
+            }
+        }
+
+        private string GetPort()
+        {
+            var portPrefix = _configuration["Weather:Port:Prefix"];
+
+            while (!_cancellationToken.IsCancellationRequested)
+            {
+                WriteLog($"Checking for port starting with: {portPrefix}");
+
+                var ports = SerialPort.GetPortNames();
+
+                var port = Array.Find(ports, p => p.StartsWith(portPrefix));
+
+                if (port != null)
+                {
+                    WriteLog($"Port found: {port}");
+                    return port;
+                }
+
+                WriteLog("Port not found - waiting");
+
+                Thread.Sleep(1000);
+            }
+
+            return null;
+        }
+
+        private static void WriteLog(string message)
+        {
+            Console.WriteLine(message);
+        }
+
+        public Task StopAsync(CancellationToken cancellationToken)
+        {
+            return Task.CompletedTask;
+        }
+    }
+}