Refactor: Remove IOutgoingEmailConsumer interface

Simplified the codebase by removing the `IOutgoingEmailConsumer` interface and directly using the `OutgoingEmailConsumer` class.

- Removed `IOutgoingEmailConsumer` from the application.
- Updated `DependencyInjection` to register `OutgoingEmailConsumer` directly.
- Modified `OutgoingEmailConsumer` to no longer implement the removed interface.
- Updated `AsyncInitWorker` to depend directly on `OutgoingEmailConsumer`.
- Simplified initialization logic for email consumer and publisher.

These changes eliminate an unnecessary abstraction layer, making the code easier to maintain while preserving functionality.

src/DigitalData.MessagingService.Infrastructure/DependencyInjection.cs

@@ -32,7 +32,7 @@ public static class DependencyInjection
         services.AddSingleton<IEncryptionService, DataProtectionEncryptionService>();
 
         // --- Email Queue (RabbitMQ) ---
-        services.AddSingleton<IOutgoingEmailConsumer, OutgoingEmailConsumer>();
+        services.AddSingleton<OutgoingEmailConsumer>();
         services.AddSingleton<IOutgoingEmailPublisher, OutgoingEmailPublisher>();
         services.AddSingleton<RabbitMqConnectionFactory>();
 

src/DigitalData.MessagingService.Infrastructure/Queue/OutgoingEmailConsumer.cs

@@ -15,7 +15,7 @@ namespace DigitalData.MessagingService.Infrastructure.Queue;
 /// Provides message persistence, scalability, and reliability.
 /// Uses Lazy<T> initialization pattern to avoid blocking constructor.
 /// </summary>
-public sealed class OutgoingEmailConsumer(IOptions<RabbitMqConfiguration> config, ILogger<OutgoingEmailConsumer> Logger, IEmailService EmailService, RabbitMqConnectionFactory CnnFactory) : IOutgoingEmailConsumer, IAsyncDisposable
+public sealed class OutgoingEmailConsumer(IOptions<RabbitMqConfiguration> config, ILogger<OutgoingEmailConsumer> Logger, IEmailService EmailService, RabbitMqConnectionFactory CnnFactory) : IAsyncDisposable
 {
     private readonly RabbitMqConfiguration _config = config.Value;
     private IChannel? _consumeChannel = null;   // Dedicated channel for consuming

src/DigitalData.MessagingService.Infrastructure/Services/Background/AsyncInitWorker.cs

@@ -10,7 +10,7 @@ namespace DigitalData.MessagingService.Infrastructure.Services.Background;
 /// Leverages a push-based, event-driven RabbitMQ consumer to eliminate polling overhead.
 /// Email account configuration is resolved exclusively from application settings; no database access is performed.
 /// </summary>
-public class AsyncInitWorker(IOutgoingEmailConsumer EmailConsumer, IOutgoingEmailPublisher EmailPublisher, RabbitMqConnectionFactory CnnFactory) : BackgroundService
+public class AsyncInitWorker(OutgoingEmailConsumer EmailConsumer, IOutgoingEmailPublisher EmailPublisher, RabbitMqConnectionFactory CnnFactory) : BackgroundService
 {
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {
@@ -18,10 +18,9 @@ public class AsyncInitWorker(IOutgoingEmailConsumer EmailConsumer, IOutgoingEmai
         // message processing is handled asynchronously via registered event callbacks.
         await CnnFactory.InitAsync(stoppingToken);
 
-        if (EmailConsumer is OutgoingEmailConsumer outgoingEmailConsumer)
-            await outgoingEmailConsumer.InitAsync();
+        await EmailConsumer.InitAsync();
 
-        if (EmailPublisher is OutgoingEmailPublisher outgoingEmailPublisher)
-            await outgoingEmailPublisher.InitAsync();
+        if (EmailPublisher is OutgoingEmailPublisher emailPublisher)
+            await emailPublisher.InitAsync();
     }
 }