Refactor: Rename OutgoingEmail to SendingEmail

This commit renames and refactors all instances of `OutgoingEmail` to `SendingEmail` across the codebase to improve terminology consistency and align with domain language.

- Renamed classes, interfaces, and records (e.g., `OutgoingEmailPublisher` → `SendingEmailPublisher`, `OutgoingEmailEvent` → `SendingEmailEvent`).
- Updated method signatures, parameters, and return types to use `SendingEmail`.
- Adjusted dependency injection registrations to reflect the new naming.
- Updated mappings in `EmailMappingProfile` to map `SendEmailCommand` to `SendingEmailEvent`.
- Refactored `SendEmailCommand` and its handler to work with `SendingEmailEvent`.
- Updated `EmailsController` to use `SendingEmailEvent` in the `SendEmail` action.
- Refactored integration tests to test `SendingEmailPublisher` and updated test data accordingly.
- Updated log messages, error handling, and comments to reflect the new terminology.
- Revised documentation and utility methods to use `SendingEmailEvent`.

This refactor ensures consistency, improves readability, and reduces ambiguity in the codebase.

src/core/DigitalData.MessagingService.Abstraction/IOutgoingEmailPublisher.cs

@@ -3,9 +3,9 @@ namespace DigitalData.MessagingService.Abstraction;
 /// <summary>
 /// Email queue interface for outgoing emails.
 /// </summary>
-public interface IOutgoingEmailPublisher
+public interface ISendingEmailPublisher
 {
-    Task EnqueueAsync(OutgoingEmailEvent outgoingEmailEvent, CancellationToken cancellationToken = default);
+    Task EnqueueAsync(SendingEmailEvent sendingEmailEvent, CancellationToken cancellationToken = default);
 
     Task<int> GetQueueDepthAsync(CancellationToken cancellationToken = default);
 }

src/core/DigitalData.MessagingService.Abstraction/OutgoingEmailCreateDto.cs

@@ -1,6 +1,6 @@
 namespace DigitalData.MessagingService.Abstraction;
 
-public record OutgoingEmailCreateDto
+public record SendingEmailCreateDto
 {
     /// <summary>
     /// Recipient email address

src/core/DigitalData.MessagingService.Abstraction/OutgoingEmailEvent.cs

@@ -1,6 +1,6 @@
 namespace DigitalData.MessagingService.Abstraction;
 
-public record OutgoingEmailEvent
+public record SendingEmailEvent
 {
     public Guid Id { get; set; }
 

src/core/DigitalData.MessagingService.Application/Common/Mappings/EmailMappingProfile.cs

@@ -11,9 +11,9 @@ public class EmailMappingProfile : Profile
 {
     public EmailMappingProfile()
     {
-        // SendEmailCommand -> OutgoingEmailEvent
+        // SendEmailCommand -> SendingEmailEvent
         // Sender is resolved via MediatR in the handler and set separately after mapping.
-        CreateMap<SendEmailCommand, OutgoingEmailEvent>()
+        CreateMap<SendEmailCommand, SendingEmailEvent>()
             .ForMember(dest => dest.Id, opt => opt.MapFrom(_ => Guid.NewGuid()))
             .ForMember(dest => dest.QueuedAt, opt => opt.MapFrom(_ => DateTime.Now))
             .ForMember(dest => dest.Sender, opt => opt.Ignore());

src/core/DigitalData.MessagingService.Application/EmailSending/Commands/SendEmailCommand.cs

@@ -9,7 +9,7 @@ namespace DigitalData.MessagingService.Application.EmailSending.Commands;
 /// <summary>
 /// Command to send an email (enqueue to RabbitMQ)
 /// </summary>
-public record SendEmailCommand : IRequest<OutgoingEmailEvent>
+public record SendEmailCommand : IRequest<SendingEmailEvent>
 {
     public required GetSenderQuery Sender { get; init; }
 
@@ -36,23 +36,23 @@ public record SendEmailCommand : IRequest<OutgoingEmailEvent>
 
 /// <summary>
 /// Handler for SendEmailCommand
-/// Resolves the sender account via MediatR, maps to OutgoingEmailEvent and enqueues to RabbitMQ
+/// Resolves the sender account via MediatR, maps to SendingEmailEvent and enqueues to RabbitMQ
 /// </summary>
 public class SendEmailCommandHandler(
 ISender Sender,
-IOutgoingEmailPublisher Publisher,
-IMapper Mapper) : IRequestHandler<SendEmailCommand, OutgoingEmailEvent>
+ISendingEmailPublisher Publisher,
+IMapper Mapper) : IRequestHandler<SendEmailCommand, SendingEmailEvent>
 {
-    public async Task<OutgoingEmailEvent> Handle(SendEmailCommand request, CancellationToken cancellationToken)
+    public async Task<SendingEmailEvent> Handle(SendEmailCommand request, CancellationToken cancellationToken)
     {
         var senderAccount = await Sender.Send(request.Sender, cancellationToken)
             ?? throw new NotFoundException(
                 $"No email account found for the given sender criteria (Id: {request.Sender.Id}, Username: {request.Sender.Username}).");
 
-        var outgoingEmailEvent = Mapper.Map<OutgoingEmailEvent>(request) with { Sender = senderAccount };
+        var sendingEmailEvent = Mapper.Map<SendingEmailEvent>(request) with { Sender = senderAccount };
 
         // Enqueue to RabbitMQ
-        await Publisher.EnqueueAsync(outgoingEmailEvent, cancellationToken);
-        return outgoingEmailEvent;
+        await Publisher.EnqueueAsync(sendingEmailEvent, cancellationToken);
+        return sendingEmailEvent;
     }
 }

src/infrastructure/DigitalData.MessagingService.Infrastructure/DependencyInjection.cs

@@ -33,7 +33,7 @@ public static class DependencyInjection
         services.AddSingleton<IEncryptionService, DataProtectionEncryptionService>();
 
         // --- Email Queue (RabbitMQ) ---
-        services.AddSingleton<OutgoingEmailConsumer>();
+        services.AddSingleton<SendingEmailConsumer>();
         services.AddMessagingServicePublisher();
 
         // --- RabbitMQ Configuration ---

src/infrastructure/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 : IAsyncDisposable
+public sealed class SendingEmailConsumer : IAsyncDisposable
 {
     private readonly RabbitMqConfiguration _config;
 
@@ -23,9 +23,9 @@ public sealed class OutgoingEmailConsumer : IAsyncDisposable
 
     private readonly Lazy<Task> _lazyInit;
 
-    private readonly ILogger<OutgoingEmailConsumer>? _logger;
+    private readonly ILogger<SendingEmailConsumer>? _logger;
 
-    public OutgoingEmailConsumer(IOptions<RabbitMqConfiguration> config, IEmailService EmailService, RabbitMqConnectionFactory CnnFactory, ILogger<OutgoingEmailConsumer>? logger = null)
+    public SendingEmailConsumer(IOptions<RabbitMqConfiguration> config, IEmailService EmailService, RabbitMqConnectionFactory CnnFactory, ILogger<SendingEmailConsumer>? logger = null)
     {
         _logger = logger;
         _config = config.Value;
@@ -38,11 +38,11 @@ public sealed class OutgoingEmailConsumer : IAsyncDisposable
 
             consumer.ReceivedAsync += async (sender, args) =>
             {
-                OutgoingEmailEvent? oMailEvent = null;
+                SendingEmailEvent? oMailEvent = null;
                 try
                 {
                     var json = Encoding.UTF8.GetString(args.Body.ToArray());
-                    oMailEvent = JsonSerializer.Deserialize<OutgoingEmailEvent>(json);
+                    oMailEvent = JsonSerializer.Deserialize<SendingEmailEvent>(json);
 
                     if (oMailEvent is not null)
                     {
@@ -69,7 +69,7 @@ public sealed class OutgoingEmailConsumer : IAsyncDisposable
 
                     // TODO: Error Reporting Strategy
                     // Option 1: Separate RabbitMQ Queue (emailprofiler.errors)
-                    //   - Create EmailErrorReport entity { OutgoingEmailEventId, Exception, StackTrace, Timestamp, RetryAttempt }
+                    //   - Create EmailErrorReport entity { SendingEmailEventId, Exception, StackTrace, Timestamp, RetryAttempt }
                     //   - Publish to error queue: await _errorQueue.EnqueueAsync(errorReport)
                     //   - Separate worker processes error queue → Log to DB/File/External monitoring
                     //
@@ -111,7 +111,7 @@ public sealed class OutgoingEmailConsumer : IAsyncDisposable
     public async Task InitAsync()
     {
         if (_lazyInit.IsValueCreated)
-            _logger?.LogWarning("OutgoingEmailConsumer already initialized. InitAsync() called multiple times.");
+            _logger?.LogWarning("SendingEmailConsumer already initialized. InitAsync() called multiple times.");
 
         await _lazyInit.Value;
     }

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

@@ -9,7 +9,7 @@ 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(OutgoingEmailConsumer EmailConsumer) : BackgroundService
+public class AsyncInitWorker(SendingEmailConsumer EmailConsumer) : BackgroundService
 {
     protected override async Task ExecuteAsync(CancellationToken stoppingToken)
     {

src/infrastructure/DigitalData.MessagingService.Publisher/DependencyInjection.cs

@@ -13,7 +13,7 @@ public static class DependencyInjection
             services.AddRabbitMqConnectionFactory(configure);
 
         // --- Email Queue (RabbitMQ) ---
-        services.AddSingleton<IOutgoingEmailPublisher, OutgoingEmailPublisher>();
+        services.AddSingleton<ISendingEmailPublisher, SendingEmailPublisher>();
 
         return services;
     }

src/infrastructure/DigitalData.MessagingService.Publisher/OutgoingEmailPublisher.cs

@@ -13,14 +13,14 @@ namespace DigitalData.MessagingService.Publisher;
 /// Provides message persistence, scalability, and reliability.
 /// Uses Lazy<T> initialization pattern to avoid blocking constructor.
 /// </summary>
-public sealed class OutgoingEmailPublisher : IOutgoingEmailPublisher, IAsyncDisposable
+public sealed class SendingEmailPublisher : ISendingEmailPublisher, IAsyncDisposable
 {
     private readonly RabbitMqConfiguration _config;
-    private readonly ILogger<OutgoingEmailPublisher> _logger;
+    private readonly ILogger<SendingEmailPublisher> _logger;
     private readonly RabbitMqConnectionFactory _cnnFactory;
     private readonly Lazy<Task<IChannel>> _lazyChannel;
 
-    public OutgoingEmailPublisher(IOptions<RabbitMqConfiguration> config, ILogger<OutgoingEmailPublisher> logger, RabbitMqConnectionFactory cnnFactory)
+    public SendingEmailPublisher(IOptions<RabbitMqConfiguration> config, ILogger<SendingEmailPublisher> logger, RabbitMqConnectionFactory cnnFactory)
     {
         _config = config.Value;
         _logger = logger;
@@ -66,9 +66,9 @@ public sealed class OutgoingEmailPublisher : IOutgoingEmailPublisher, IAsyncDisp
         return channel;
     }
     
-    public async Task EnqueueAsync(OutgoingEmailEvent outgoingEmailEvent, CancellationToken cancellationToken = default)
+    public async Task EnqueueAsync(SendingEmailEvent sendingEmailEvent, CancellationToken cancellationToken = default)
     {
-        var json = JsonSerializer.Serialize(outgoingEmailEvent);
+        var json = JsonSerializer.Serialize(sendingEmailEvent);
         var body = Encoding.UTF8.GetBytes(json);
 
         var properties = new BasicProperties

src/presentation/DigitalData.MessagingService.API/Controllers/EmailsController.cs

@@ -23,11 +23,11 @@ public class EmailsController(IMediator mediator) : ControllerBase
     [ProducesResponseType(StatusCodes.Status400BadRequest)]
     public async Task<IActionResult> SendEmail([FromBody] SendEmailCommand command, CancellationToken cancellationToken)
     {
-        var outgoingEmailEvent = await mediator.Send(command, cancellationToken);
+        var sendingEmailEvent = await mediator.Send(command, cancellationToken);
 
         return Accepted(new
         {
-            outgoingEmailEvent.Id,
+            sendingEmailEvent.Id,
         });
     }
 }

src/presentation/DigitalData.MessagingService.Client/Email.cs

@@ -28,12 +28,12 @@ public record Email
     public bool IsHtml { get; set; } = true;
 
     /// <summary>
-    /// Converts this <see cref="Email"/> instance to an <see cref="OutgoingEmailEvent"/>.
+    /// Converts this <see cref="Email"/> instance to an <see cref="SendingEmailEvent"/>.
     /// </summary>
-    /// <returns>A new <see cref="OutgoingEmailEvent"/> representing this email.</returns>
-    internal OutgoingEmailEvent ToEvent()
+    /// <returns>A new <see cref="SendingEmailEvent"/> representing this email.</returns>
+    internal SendingEmailEvent ToEvent()
     {
-        return new OutgoingEmailEvent
+        return new SendingEmailEvent
         {
             Id = Guid.NewGuid(),
             Recipients = Recipients,

src/presentation/DigitalData.MessagingService.Client/EmailSender.cs

@@ -113,8 +113,8 @@ public static class EmailSender
     /// Thrown when <see cref="ConnectRabbitMq(Action{RabbitMqConfiguration}, OnReconnect)"/> has not been called prior to sending.
     /// </exception>
     /// <remarks>
-    /// This method maps <see cref="Email"/> to <see cref="OutgoingEmailEvent"/>,
-    /// then resolves <see cref="IOutgoingEmailPublisher"/> from the internal
+    /// This method maps <see cref="Email"/> to <see cref="SendingEmailEvent"/>,
+    /// then resolves <see cref="ISendingEmailPublisher"/> from the internal
     /// service provider and calls <c>EnqueueAsync</c> in a fire-and-forget manner.
     /// Ensure that any unhandled exceptions from the async operation are handled
     /// at the publisher level.
@@ -124,7 +124,7 @@ public static class EmailSender
         if(!IsConnected)
             throw new InvalidOperationException("Messaging service is not connected. Call ConnectRabbitMq first.");
 
-        var publisher = LazyProvider.Value.GetRequiredService<IOutgoingEmailPublisher>();
+        var publisher = LazyProvider.Value.GetRequiredService<ISendingEmailPublisher>();
         publisher.EnqueueAsync(email.ToEvent());
     }
 }