[PM-17562] Refactor existing RabbitMq implementation (#5357)

* [PM-17562] Refactor existing RabbitMq implementation

* Fixed issues noted in PR review

src/Core/Services/EventLoggingListenerService.cs

@@ -0,0 +1,13 @@
+using Microsoft.Extensions.Hosting;
+
+namespace Bit.Core.Services;
+
+public abstract class EventLoggingListenerService : BackgroundService
+{
+    protected readonly IEventMessageHandler _handler;
+
+    protected EventLoggingListenerService(IEventMessageHandler handler)
+    {
+        _handler = handler ?? throw new ArgumentNullException(nameof(handler));
+    }
+}

src/Core/Services/Implementations/RabbitMqEventListenerService.cs

@@ -0,0 +1,92 @@
+using System.Text.Json;
+using Bit.Core.Models.Data;
+using Bit.Core.Settings;
+using Microsoft.Extensions.Logging;
+using RabbitMQ.Client;
+using RabbitMQ.Client.Events;
+
+namespace Bit.Core.Services;
+
+public class RabbitMqEventListenerService : EventLoggingListenerService
+{
+    private IChannel _channel;
+    private IConnection _connection;
+    private readonly string _exchangeName;
+    private readonly ConnectionFactory _factory;
+    private readonly ILogger<RabbitMqEventListenerService> _logger;
+    private readonly string _queueName;
+
+    public RabbitMqEventListenerService(
+        IEventMessageHandler handler,
+        ILogger<RabbitMqEventListenerService> logger,
+        GlobalSettings globalSettings,
+        string queueName) : base(handler)
+    {
+        _factory = new ConnectionFactory
+        {
+            HostName = globalSettings.EventLogging.RabbitMq.HostName,
+            UserName = globalSettings.EventLogging.RabbitMq.Username,
+            Password = globalSettings.EventLogging.RabbitMq.Password
+        };
+        _exchangeName = globalSettings.EventLogging.RabbitMq.ExchangeName;
+        _logger = logger;
+        _queueName = queueName;
+    }
+
+    public override async Task StartAsync(CancellationToken cancellationToken)
+    {
+        _connection = await _factory.CreateConnectionAsync(cancellationToken);
+        _channel = await _connection.CreateChannelAsync(cancellationToken: cancellationToken);
+
+        await _channel.ExchangeDeclareAsync(exchange: _exchangeName, type: ExchangeType.Fanout, durable: true);
+        await _channel.QueueDeclareAsync(queue: _queueName,
+                                         durable: true,
+                                         exclusive: false,
+                                         autoDelete: false,
+                                         arguments: null,
+                                         cancellationToken: cancellationToken);
+        await _channel.QueueBindAsync(queue: _queueName,
+                                      exchange: _exchangeName,
+                                      routingKey: string.Empty,
+                                      cancellationToken: cancellationToken);
+        await base.StartAsync(cancellationToken);
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        var consumer = new AsyncEventingBasicConsumer(_channel);
+        consumer.ReceivedAsync += async (_, eventArgs) =>
+        {
+            try
+            {
+                var eventMessage = JsonSerializer.Deserialize<EventMessage>(eventArgs.Body.Span);
+                await _handler.HandleEventAsync(eventMessage);
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "An error occurred while processing the message");
+            }
+        };
+
+        await _channel.BasicConsumeAsync(_queueName, autoAck: true, consumer: consumer, cancellationToken: stoppingToken);
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            await Task.Delay(1_000, stoppingToken);
+        }
+    }
+
+    public override async Task StopAsync(CancellationToken cancellationToken)
+    {
+        await _channel.CloseAsync();
+        await _connection.CloseAsync();
+        await base.StopAsync(cancellationToken);
+    }
+
+    public override void Dispose()
+    {
+        _channel.Dispose();
+        _connection.Dispose();
+        base.Dispose();
+    }
+}