From 1c9af0e56059ed5eef85a6bfc6f05f540f504f7a Mon Sep 17 00:00:00 2001
From: TekH <h.tek@digitaldata.works>
Date: Thu, 13 Aug 2026 12:07:20 +0200
Subject: [PATCH] Remove caching from LimilabsImapEmailService

Simplified the `LimilabsImapEmailService` by removing the dependency on `IMemoryCache` and eliminating all caching logic. The constructor no longer accepts an `IMemoryCache` parameter, and the static `CacheKeyPrefix` field has been removed.

Replaced the caching mechanism with direct email fetching using `imap.GetMessageByUIDAsync`. Refactored the logic for processing attachments and visuals into `EmailAttachmentDto` objects, and streamlined the construction of `ReceivedEmailDto` to include metadata directly from the fetched email data.

These changes reduce complexity, improve maintainability, and ensure the service always retrieves the latest email data from the IMAP server.
---
 .../Services/LimilabsImapEmailService.cs      | 95 ++++++++-----------
 1 file changed, 42 insertions(+), 53 deletions(-)

diff --git a/src/infrastructure/DigitalData.MessagingService.Infrastructure/Services/LimilabsImapEmailService.cs b/src/infrastructure/DigitalData.MessagingService.Infrastructure/Services/LimilabsImapEmailService.cs
index cd7a81b..1fc0e05 100644
--- a/src/infrastructure/DigitalData.MessagingService.Infrastructure/Services/LimilabsImapEmailService.cs
+++ b/src/infrastructure/DigitalData.MessagingService.Infrastructure/Services/LimilabsImapEmailService.cs
@@ -6,7 +6,6 @@ using DigitalData.MessagingService.Domain.Exceptions;
 using DigitalData.MessagingService.Infrastructure.Services.Extensions;
 using Limilabs.Client.IMAP;
 using Limilabs.Mail;
-using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Logging;
 using System.Text;
 
@@ -16,10 +15,8 @@ namespace DigitalData.MessagingService.Infrastructure.Services;
 /// IMAP email service using Limilabs Mail.dll.
 /// Opens a fresh connection per call — stateless and thread-safe.
 /// </summary>
-public class LimilabsImapEmailService(ILogger<LimilabsImapEmailService> Logger, IMemoryCache Cache) : IImapEmailService
+public class LimilabsImapEmailService(ILogger<LimilabsImapEmailService> Logger) : IImapEmailService
 {
-    private static readonly string CacheKeyPrefix = Guid.NewGuid().ToString();
-
     static LimilabsImapEmailService()
     {
         Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
@@ -67,58 +64,50 @@ public class LimilabsImapEmailService(ILogger<LimilabsImapEmailService> Logger,
                 try
                 {
                     #region Read email
-                    var email = await Cache.GetOrCreateAsync(
-                        CacheKeyPrefix + uid,
-                        async entry =>
+                    var eml = await imap.GetMessageByUIDAsync(uid, cancel);
+                    var mail = new MailBuilder().CreateFromEml(eml);
+                    var flags = await imap.GetFlagsByUIDAsync(uid, cancel);
+
+                    var attachments = new List<EmailAttachmentDto>();
+
+                    foreach (var att in mail.Attachments)
+                    {
+                        attachments.Add(new EmailAttachmentDto
                         {
-                            var eml = await imap.GetMessageByUIDAsync(uid, cancel);
-                            var mail = new MailBuilder().CreateFromEml(eml);
-                            var flags = await imap.GetFlagsByUIDAsync(uid, cancel);
-
-                            var attachments = new List<EmailAttachmentDto>();
-
-                            foreach (var att in mail.Attachments)
-                            {
-                                attachments.Add(new EmailAttachmentDto
-                                {
-                                    FileName = att.FileName ?? "attachment",
-                                    Content = att.Data,
-                                    ContentType = att.ContentType?.ToString() ?? "application/octet-stream",
-                                    IsInline = false,
-                                    ContentId = att.ContentId
-                                });
-                            }
-
-                            foreach (var vis in mail.Visuals)
-                            {
-                                attachments.Add(new EmailAttachmentDto
-                                {
-                                    FileName = vis.FileName ?? "inline",
-                                    Content = vis.Data,
-                                    ContentType = vis.ContentType?.ToString() ?? "application/octet-stream",
-                                    IsInline = true,
-                                    ContentId = vis.ContentId
-                                });
-                            }
-
-                            return new ReceivedEmailDto
-                            {
-                                Uid = uid,
-                                From = mail.From.FirstOrDefault()?.Address ?? string.Empty,
-                                To = [.. mail.To.SelectMany(m => m.GetMailboxes()).Select(mb => mb.Address)],
-                                Cc = [.. mail.Cc.SelectMany(m => m.GetMailboxes()).Select(mb => mb.Address)],
-                                Subject = mail.Subject ?? string.Empty,
-                                TextBody = mail.Text ?? string.Empty,
-                                HtmlBody = mail.Html ?? string.Empty,
-                                Date = mail.Date ?? DateTime.MinValue,
-                                IsSeen = flags.Contains(Flag.Seen),
-                                Attachments = attachments,
-                            };
+                            FileName = att.FileName ?? "attachment",
+                            Content = att.Data,
+                            ContentType = att.ContentType?.ToString() ?? "application/octet-stream",
+                            IsInline = false,
+                            ContentId = att.ContentId
                         });
-                    #endregion Read email
+                    }
 
-                    if (email is null)
-                        continue;
+                    foreach (var vis in mail.Visuals)
+                    {
+                        attachments.Add(new EmailAttachmentDto
+                        {
+                            FileName = vis.FileName ?? "inline",
+                            Content = vis.Data,
+                            ContentType = vis.ContentType?.ToString() ?? "application/octet-stream",
+                            IsInline = true,
+                            ContentId = vis.ContentId
+                        });
+                    }
+
+                    var email = new ReceivedEmailDto
+                    {
+                        Uid = uid,
+                        From = mail.From.FirstOrDefault()?.Address ?? string.Empty,
+                        To = [.. mail.To.SelectMany(m => m.GetMailboxes()).Select(mb => mb.Address)],
+                        Cc = [.. mail.Cc.SelectMany(m => m.GetMailboxes()).Select(mb => mb.Address)],
+                        Subject = mail.Subject ?? string.Empty,
+                        TextBody = mail.Text ?? string.Empty,
+                        HtmlBody = mail.Html ?? string.Empty,
+                        Date = mail.Date ?? DateTime.MinValue,
+                        IsSeen = flags.Contains(Flag.Seen),
+                        Attachments = attachments,
+                    };
+                    #endregion Read email
 
                     if (filter.UnseenOnly && email.IsSeen)
                         continue;