Rename EmailsController to EmailController

Updated the class name from EmailsController to EmailController to follow a singular naming convention for controller classes. The namespace and constructor signature remain unchanged. This change improves consistency and readability in the codebase without introducing any functional modifications.

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

@@ -0,0 +1,132 @@
+using DigitalData.MessagingService.Application.EmailSending.Commands;
+using DigitalData.MessagingService.Application.EmailReceiving.Queries;
+using DigitalData.MessagingService.Application.EmailReceiving.Commands;
+using DigitalData.MessagingService.Application.EmailAccount.Queries;
+using DigitalData.MessagingService.Abstraction;
+using MediatR;
+using Microsoft.AspNetCore.Mvc;
+
+namespace DigitalData.MessagingService.API.Controllers;
+
+/// <summary>
+/// Email sending API controller.
+/// Enqueues outgoing emails to RabbitMQ for async processing.
+/// </summary>
+[ApiController]
+[Route("api/[controller]")]
+public class EmailController(IMediator mediator) : ControllerBase
+{
+    #region Send
+    /// <summary>
+    /// Send an email, optionally with file attachments.
+    /// Omit the <c>attachments</c> field for a plain send.
+    /// </summary>
+    /// <param name="command">Email fields as form values</param>
+    /// <param name="attachments">Optional uploaded files</param>
+    /// <param name="cancellationToken">Cancellation token</param>
+    /// <returns>HTTP 202 Accepted with the queued event ID</returns>
+    [HttpPost]
+    [Consumes("multipart/form-data")]
+    [ProducesResponseType(StatusCodes.Status202Accepted)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    public async Task<IActionResult> SendEmail(
+        [FromForm] PublishEmailCommand command,
+        IFormFileCollection? attachments,
+        CancellationToken cancellationToken)
+    {
+        var commandWithAttachments = command.WithAttachments(
+            await BuildAttachmentsAsync(attachments, cancellationToken));
+
+        var eventId = await mediator.Send(commandWithAttachments, cancellationToken);
+        return Accepted(new { Id = eventId });
+    }
+
+    private static async Task<IEnumerable<EmailAttachmentContext>> BuildAttachmentsAsync(
+        IFormFileCollection? files,
+        CancellationToken cancellationToken)
+    {
+        if (files is null || files.Count == 0)
+            return [];
+
+        var result = new List<EmailAttachmentContext>(files.Count);
+
+        foreach (var file in files)
+        {
+            using var ms = new MemoryStream();
+            await file.CopyToAsync(ms, cancellationToken);
+
+            result.Add(new EmailAttachmentContext
+            {
+                FileName    = file.FileName,
+                Content     = ms.ToArray(),
+                ContentType = file.ContentType
+            });
+        }
+
+        return result;
+    }
+    #endregion Send
+
+    #region Receive
+    /// <summary>
+    /// Fetch emails from an IMAP mailbox.
+    /// </summary>
+    /// <param name="accountId">Id of the email account (must have ImapServer configured).</param>
+    /// <param name="folder">Mailbox folder to read (default: INBOX).</param>
+    /// <param name="unseenOnly">Return only unread messages.</param>
+    /// <param name="maxCount">Maximum number of messages to return (most-recent first, default: 50).</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>HTTP 200 with list of received emails.</returns>
+    [HttpGet]
+    [ProducesResponseType(StatusCodes.Status200OK)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<IActionResult> FetchEmails(
+        [FromQuery] int accountId,
+        [FromQuery] string folder = "INBOX",
+        [FromQuery] bool unseenOnly = false,
+        [FromQuery] int maxCount = 50,
+        CancellationToken cancellationToken = default)
+    {
+        var query = new FetchEmailsQuery
+        {
+            Account = new GetSenderQuery { Id = accountId },
+            Folder = folder,
+            UnseenOnly = unseenOnly,
+            MaxCount = maxCount
+        };
+
+        var emails = await mediator.Send(query, cancellationToken);
+        return Ok(emails);
+    }
+
+    /// <summary>
+    /// Mark a single IMAP message as seen (read).
+    /// </summary>
+    /// <param name="accountId">Id of the email account.</param>
+    /// <param name="uid">UID of the message on the IMAP server.</param>
+    /// <param name="folder">Mailbox folder the message resides in (default: INBOX).</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>HTTP 204 No Content.</returns>
+    [HttpPatch("{uid}/seen")]
+    [ProducesResponseType(StatusCodes.Status204NoContent)]
+    [ProducesResponseType(StatusCodes.Status400BadRequest)]
+    [ProducesResponseType(StatusCodes.Status404NotFound)]
+    public async Task<IActionResult> MarkAsSeen(
+        [FromRoute] long uid,
+        [FromQuery] int accountId,
+        [FromQuery] string folder = "INBOX",
+        CancellationToken cancellationToken = default)
+    {
+        var command = new MarkEmailAsSeenCommand
+        {
+            Account = new GetSenderQuery { Id = accountId },
+            Uid = uid,
+            Folder = folder
+        };
+
+        await mediator.Send(command, cancellationToken);
+        return NoContent();
+    }
+    #endregion Receive
+}