feat: add persistence and restoration of email template filters in UI and backend

- Extract email template handling, rendering, and sending code into `Worker.Services` project.
- Introduce `EmailTemplateService`, `EmailTemplateRenderingService`, and `SendEmailService`.
- Simplify consumer logic by delegating to scoped services.
- Update project dependencies and package references accordingly.

HrynCo.NotificationService.DAL.Abstract/Repositories/IEmailTemplateRepository.cs

@@ -4,7 +4,7 @@ namespace HrynCo.NotificationService.DAL.Abstract.Repositories;
 
 public interface IEmailTemplateRepository
 {
-    Task<IReadOnlyList<EmailTemplate>> GetAllAsync(CancellationToken ct = default);
+    Task<IReadOnlyList<EmailTemplate>> GetAllAsync(string? serviceName = null, string? key = null, CancellationToken ct = default);
     Task<IReadOnlyList<EmailTemplate>> GetByServiceAsync(string serviceName, CancellationToken ct = default);
     Task<EmailTemplate?> GetAsync(string serviceName, string key, string languageCode, CancellationToken ct = default);
     Task AddAsync(EmailTemplate template, CancellationToken ct = default);

HrynCo.NotificationService.DAL.EF/Repositories/EmailTemplateRepository.cs

@@ -13,9 +13,22 @@ internal sealed class EmailTemplateRepository
     {
     }
 
-    public async Task<IReadOnlyList<EmailTemplate>> GetAllAsync(CancellationToken ct = default)
+    public async Task<IReadOnlyList<EmailTemplate>> GetAllAsync(string? serviceName = null, string? key = null, CancellationToken ct = default)
     {
-        List<EmailTemplateEntity> entities = await EfRepository.Get()
+        IQueryable<EmailTemplateEntity> query = EfRepository.Get();
+
+        if (!string.IsNullOrWhiteSpace(serviceName))
+        {
+            query = query.Where(x => x.ServiceName == serviceName);
+        }
+
+        if (!string.IsNullOrWhiteSpace(key))
+        {
+            query = query.Where(x => x.Key == key);
+        }
+
+        List<EmailTemplateEntity> entities = await query
+            .OrderBy(x => x.ServiceName).ThenBy(x => x.Key)
             .AsNoTracking()
             .ToListAsync(ct);
         return entities.Select(MapToDomain).ToList();

HrynCo.NotificationService.Services/EmailChannels/Send/SendEmailHandler.cs

@@ -1,5 +1,6 @@
 using System.Net;
 using System.Net.Mail;
+using System.Text;
 using HrynCo.NotificationService.DAL.Abstract.Providers;
 using HrynCo.NotificationService.DAL.Abstract.Repositories;
 using HrynCo.NotificationService.Services.Core;
@@ -48,14 +49,16 @@ internal sealed class SendEmailHandler
             {
                 From = new MailAddress(smtp.FromEmail, smtp.FromName),
                 Subject = request.Subject,
-                Body = request.HtmlBody,
-                IsBodyHtml = true
+                Body = request.TextBody ?? string.Empty,
+                IsBodyHtml = false,
+                BodyEncoding = Encoding.UTF8,
+                SubjectEncoding = Encoding.UTF8
             };
 
-            if (!string.IsNullOrWhiteSpace(request.TextBody))
+            if (!string.IsNullOrWhiteSpace(request.HtmlBody))
             {
-                var plain = AlternateView.CreateAlternateViewFromString(request.TextBody, null, "text/plain");
-                mail.AlternateViews.Add(plain);
+                var html = AlternateView.CreateAlternateViewFromString(request.HtmlBody, Encoding.UTF8, "text/html");
+                mail.AlternateViews.Add(html);
             }
 
             mail.To.Add(new MailAddress(request.RecipientEmail, request.RecipientName));

HrynCo.NotificationService.Services/EmailTemplates/GetAll/GetAllEmailTemplatesHandler.cs

@@ -22,7 +22,7 @@ internal sealed class GetAllEmailTemplatesHandler
     protected override async Task<ServiceResult<IReadOnlyList<EmailTemplate>>> DoOnHandle(
         GetAllEmailTemplatesQuery request, CancellationToken cancellationToken)
     {
-        var templates = await _templates.GetAllAsync(cancellationToken);
+        var templates = await _templates.GetAllAsync(request.ServiceName, request.Key, cancellationToken);
         return Success(templates);
     }
 }

HrynCo.NotificationService.Services/EmailTemplates/GetAll/GetAllEmailTemplatesQuery.cs

@@ -4,4 +4,5 @@ using HrynCo.NotificationService.Services.Core;
 
 namespace HrynCo.NotificationService.Services.EmailTemplates.GetAll;
 
-public sealed record GetAllEmailTemplatesQuery : IRequest<ServiceResult<IReadOnlyList<EmailTemplate>>>;
+public sealed record GetAllEmailTemplatesQuery(string? ServiceName = null, string? Key = null)
+    : IRequest<ServiceResult<IReadOnlyList<EmailTemplate>>>;

HrynCo.NotificationService.Web/Controllers/Admin/AdminTemplatesController.cs

@@ -23,9 +23,12 @@ public class AdminTemplatesController : Controller
 
     // GET /admin/templates
     [HttpGet("")]
-    public async Task<IActionResult> Index(CancellationToken ct)
+    public async Task<IActionResult> Index([FromQuery] string? serviceName, [FromQuery] string? key, CancellationToken ct)
     {
-        var result = await _mediator.Send(new GetAllEmailTemplatesQuery(), ct);
+        ViewData["ServiceNameFilter"] = serviceName;
+        ViewData["KeyFilter"] = key;
+
+        var result = await _mediator.Send(new GetAllEmailTemplatesQuery(serviceName, key), ct);
         if (!result.IsSuccess)
         {
             ModelState.AddModelError("", result.Error?.Message ?? "Failed to load templates.");
@@ -37,14 +40,24 @@ public class AdminTemplatesController : Controller
 
     // GET /admin/templates/create
     [HttpGet("create")]
-    public IActionResult Create()
+    public IActionResult Create([FromQuery] string? serviceNameFilter, [FromQuery] string? keyFilter)
     {
-        return View("Edit", new EmailTemplateEditViewModel());
+        return View("Edit", new EmailTemplateEditViewModel
+        {
+            ServiceNameFilter = serviceNameFilter,
+            KeyFilter = keyFilter
+        });
     }
 
     // GET /admin/templates/{serviceName}/{key}/{languageCode}
     [HttpGet("{serviceName}/{key}/{languageCode}")]
-    public async Task<IActionResult> Edit(string serviceName, string key, string languageCode, CancellationToken ct)
+    public async Task<IActionResult> Edit(
+        string serviceName,
+        string key,
+        string languageCode,
+        [FromQuery] string? serviceNameFilter,
+        [FromQuery] string? keyFilter,
+        CancellationToken ct)
     {
         var result = await _mediator.Send(new GetEmailTemplateQuery(serviceName, key, languageCode), ct);
         if (!result.IsSuccess || result.Result is null)
@@ -60,7 +73,9 @@ public class AdminTemplatesController : Controller
             Subject = template.Subject,
             HtmlBody = template.HtmlBody,
             TextBody = template.TextBody,
-            VariablesJson = JsonSerializer.Serialize(template.Variables)
+            VariablesJson = JsonSerializer.Serialize(template.Variables),
+            ServiceNameFilter = serviceNameFilter,
+            KeyFilter = keyFilter
         };
 
         return View(vm);
@@ -124,15 +139,21 @@ public class AdminTemplatesController : Controller
             }
         }
 
-        return RedirectToAction(nameof(Index));
+        return RedirectToAction(nameof(Index), new { serviceName = model.ServiceNameFilter, key = model.KeyFilter });
     }
 
     // POST /admin/templates/{serviceName}/{key}/{languageCode}/delete
     [HttpPost("{serviceName}/{key}/{languageCode}/delete")]
     [ValidateAntiForgeryToken]
-    public async Task<IActionResult> Delete(string serviceName, string key, string languageCode, CancellationToken ct)
+    public async Task<IActionResult> Delete(
+        string serviceName,
+        string key,
+        string languageCode,
+        [FromForm] string? serviceNameFilter,
+        [FromForm] string? keyFilter,
+        CancellationToken ct)
     {
         await _mediator.Send(new DeleteEmailTemplateCommand(serviceName, key, languageCode), ct);
-        return RedirectToAction(nameof(Index));
+        return RedirectToAction(nameof(Index), new { serviceName = serviceNameFilter, key = keyFilter });
     }
 }

HrynCo.NotificationService.Web/Controllers/Admin/ViewModels/EmailTemplateEditViewModel.cs

@@ -25,6 +25,8 @@ public class EmailTemplateEditViewModel
 
     // JSON array: [{"name":"UserName","required":true}, ...]
     public string VariablesJson { get; set; } = "[]";
+    public string? ServiceNameFilter { get; set; }
+    public string? KeyFilter { get; set; }
 
     public bool IsNew => Id == null;
     public string PageTitle => IsNew ? "Create Email Template" : "Edit Email Template";

HrynCo.NotificationService.Web/Controllers/Api/EmailTemplates/EmailTemplatesController.cs

@@ -1,6 +1,7 @@
 using HrynCo.NotificationService.Web.Infrastructure;
 using HrynCo.NotificationService.Services.EmailTemplates.Create;
 using HrynCo.NotificationService.Services.EmailTemplates.Delete;
+using HrynCo.NotificationService.Services.EmailTemplates.GetAll;
 using HrynCo.NotificationService.Services.EmailTemplates.Get;
 using HrynCo.NotificationService.Services.EmailTemplates.GetByService;
 using HrynCo.NotificationService.Services.EmailTemplates.Update;
@@ -15,9 +16,9 @@ public sealed class EmailTemplatesController : ApiControllerBase
     public EmailTemplatesController(IMediator mediator) : base(mediator) { }
 
     [HttpGet]
-    public async Task<IActionResult> GetAll([FromQuery] string serviceName, CancellationToken cancellationToken)
+    public async Task<IActionResult> GetAll([FromQuery] string? serviceName, [FromQuery] string? key, CancellationToken cancellationToken)
     {
-        var result = await Mediator.Send(new GetEmailTemplatesQuery(serviceName), cancellationToken);
+        var result = await Mediator.Send(new GetAllEmailTemplatesQuery(serviceName, key), cancellationToken);
         return FromServiceResult(result);
     }
 

HrynCo.NotificationService.Web/Program.cs

@@ -3,11 +3,11 @@ using HrynCo.NotificationService.DAL.EF;
 using HrynCo.NotificationService.Services;
 using Scalar.AspNetCore;
 
-var builder = WebApplication.CreateBuilder(args);
+WebApplicationBuilder builder = WebApplication.CreateBuilder(args);
 
 builder.AddSerilog();
 
-var appSettings = builder.Configuration
+AppSettings appSettings = builder.Configuration
     .GetSection(AppSettings.SectionName)
     .Get<AppSettings>() ?? throw new InvalidOperationException("App settings are not configured.");
 
@@ -18,17 +18,14 @@ builder.Services.AddControllersWithViews()
 builder.Services.AddNotificationDataAccess(appSettings.ConnectionString);
 builder.Services.AddNotificationServices();
 
-var app = builder.Build();
+WebApplication app = builder.Build();
 
-if (app.Environment.IsDevelopment())
+app.MapOpenApi();
+app.MapScalarApiReference(options =>
 {
-    app.MapOpenApi();
-    app.MapScalarApiReference(options =>
-    {
     options.Title = "HrynCo Notification Service";
     options.Theme = ScalarTheme.DeepSpace;
-    });
-}
+});
 
 app.UseStaticFiles();
 app.UseHttpsRedirection();

HrynCo.NotificationService.Web/Views/AdminTemplates/Edit.cshtml

@@ -10,6 +10,8 @@
     @Html.AntiForgeryToken()
     <input asp-for="Id" type="hidden" />
     <input type="hidden" name="IsNew" value="@Model.IsNew" />
+    <input asp-for="ServiceNameFilter" type="hidden" />
+    <input asp-for="KeyFilter" type="hidden" />
 
     @if (!ViewData.ModelState.IsValid)
     {
@@ -116,7 +118,7 @@
         <button type="submit" form="templateForm" class="btn btn-primary">
             <i class="bi bi-floppy me-1"></i> Save
         </button>
-        <a href="/admin/templates" class="btn btn-secondary">
+        <a href="/admin/templates@(string.IsNullOrWhiteSpace(Model.ServiceNameFilter) && string.IsNullOrWhiteSpace(Model.KeyFilter) ? string.Empty : $"?serviceName={Uri.EscapeDataString(Model.ServiceNameFilter ?? string.Empty)}&key={Uri.EscapeDataString(Model.KeyFilter ?? string.Empty)}")" class="btn btn-secondary">
             <i class="bi bi-x-lg me-1"></i> Cancel
         </a>
     }

HrynCo.NotificationService.Web/Views/AdminTemplates/Index.cshtml

@@ -2,15 +2,50 @@
 @model IReadOnlyList<EmailTemplate>
 @{
     ViewData["Title"] = "Email Templates";
+    var serviceNameFilter = ViewData["ServiceNameFilter"] as string ?? string.Empty;
+    var keyFilter = ViewData["KeyFilter"] as string ?? string.Empty;
+    var filterQuery = string.IsNullOrWhiteSpace(serviceNameFilter) && string.IsNullOrWhiteSpace(keyFilter)
+        ? string.Empty
+        : $"?serviceNameFilter={Uri.EscapeDataString(serviceNameFilter)}&keyFilter={Uri.EscapeDataString(keyFilter)}";
+    var listQuery = string.IsNullOrWhiteSpace(serviceNameFilter) && string.IsNullOrWhiteSpace(keyFilter)
+        ? string.Empty
+        : $"?serviceName={Uri.EscapeDataString(serviceNameFilter)}&key={Uri.EscapeDataString(keyFilter)}";
 }
 
 <div class="page-header">
     <h2><i class="bi bi-envelope-paper"></i> Email Templates</h2>
-    <a href="/admin/templates/create" class="btn btn-primary btn-sm">
+    <a href="/admin/templates/create@filterQuery" class="btn btn-primary btn-sm">
         <i class="bi bi-plus-lg me-1"></i> Create New Template
     </a>
 </div>
 
+<div class="card shadow-sm mb-3">
+    <div class="card-body">
+        <form id="templateFiltersForm" method="get" action="/admin/templates" class="row g-2 align-items-end">
+            <div class="col-12 col-md-5">
+                <label class="form-label fw-semibold" for="serviceName">Service Name</label>
+                <input id="serviceName"
+                       name="serviceName"
+                       value="@serviceNameFilter"
+                       class="form-control"
+                       placeholder="Filter by service name" />
+            </div>
+            <div class="col-12 col-md-5">
+                <label class="form-label fw-semibold" for="key">Key</label>
+                <input id="key"
+                       name="key"
+                       value="@keyFilter"
+                       class="form-control"
+                       placeholder="Filter by key" />
+            </div>
+            <div class="col-12 col-md-2 d-flex gap-2">
+                <button type="submit" class="btn btn-primary w-100">Filter</button>
+                <a id="clearTemplateFilters" href="/admin/templates" class="btn btn-outline-secondary w-100">Clear</a>
+            </div>
+        </form>
+    </div>
+</div>
+
 @if (!ViewData.ModelState.IsValid)
 {
     <div class="alert alert-danger">
@@ -21,6 +56,61 @@
     </div>
 }
 
+<script>
+    (() => {
+        const storageKey = 'hrynco.notificationService.adminTemplates.filters';
+        const form = document.getElementById('templateFiltersForm');
+        const serviceNameInput = document.getElementById('serviceName');
+        const keyInput = document.getElementById('key');
+        const clearLink = document.getElementById('clearTemplateFilters');
+
+        if (!form || !serviceNameInput || !keyInput || !clearLink) {
+            return;
+        }
+
+        const saveState = () => {
+            const state = {
+                serviceName: serviceNameInput.value ?? '',
+                key: keyInput.value ?? ''
+            };
+
+            localStorage.setItem(storageKey, JSON.stringify(state));
+        };
+
+        const restoreState = () => {
+            const raw = localStorage.getItem(storageKey);
+            if (!raw) {
+                return false;
+            }
+
+            try {
+                const state = JSON.parse(raw);
+                const serviceName = typeof state.serviceName === 'string' ? state.serviceName : '';
+                const key = typeof state.key === 'string' ? state.key : '';
+
+                serviceNameInput.value = serviceName;
+                keyInput.value = key;
+
+                return serviceName.length > 0 || key.length > 0;
+            } catch {
+                localStorage.removeItem(storageKey);
+                return false;
+            }
+        };
+
+        form.addEventListener('submit', saveState);
+        clearLink.addEventListener('click', () => localStorage.removeItem(storageKey));
+
+        const hasQueryParams = new URLSearchParams(window.location.search).toString().length > 0;
+        if (!hasQueryParams && restoreState()) {
+            form.requestSubmit();
+            return;
+        }
+
+        saveState();
+    })();
+</script>
+
 @if (Model is null || Model.Count == 0)
 {
     <div class="card shadow-sm table-card">
@@ -56,13 +146,15 @@ else
                             <td>@t.LanguageCode</td>
                             <td>@t.Subject</td>
                             <td class="text-end">
-                                <a href="/admin/templates/@t.ServiceName/@t.Key/@t.LanguageCode"
+                                <a href="/admin/templates/@t.ServiceName/@t.Key/@t.LanguageCode@filterQuery"
                                    class="btn btn-sm btn-outline-primary me-1">
                                     <i class="bi bi-pencil"></i> Edit
                                 </a>
                                 <form method="post"
                                       action="/admin/templates/@t.ServiceName/@t.Key/@t.LanguageCode/delete"
                                       class="d-inline">
+                                    <input type="hidden" name="serviceNameFilter" value="@serviceNameFilter" />
+                                    <input type="hidden" name="keyFilter" value="@keyFilter" />
                                     @Html.AntiForgeryToken()
                                     <button type="submit"
                                             class="btn btn-sm btn-outline-danger"

HrynCo.NotificationService.Worker.Services/EmailProcessing/EmailTemplateRenderingService.cs

@@ -0,0 +1,24 @@
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+using System.Text;
+using HrynCo.NotificationService.Contracts.Messages;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+
+internal sealed class EmailTemplateRenderingService : IEmailTemplateRenderingService
+{
+    public RenderedEmail Render(EmailTemplate template, SendEmailMessageData data)
+    {
+        return new RenderedEmail(
+            Interpolate(template.Subject, data.Variables),
+            Interpolate(template.HtmlBody, data.Variables),
+            Interpolate(template.TextBody, data.Variables));
+    }
+
+    private static string Interpolate(string text, IReadOnlyDictionary<string, string> variables)
+    {
+        var sb = new StringBuilder(text);
+        foreach (var (key, value) in variables)
+            sb.Replace($"{{{{{key}}}}}", value);
+        return sb.ToString();
+    }
+}

HrynCo.NotificationService.Worker.Services/EmailProcessing/EmailTemplateService.cs

@@ -0,0 +1,31 @@
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+using HrynCo.NotificationService.DAL.Abstract.Repositories;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+
+internal sealed class EmailTemplateService : IEmailTemplateService
+{
+    private readonly IEmailTemplateRepository _templateRepository;
+
+    public EmailTemplateService(IEmailTemplateRepository templateRepository)
+    {
+        _templateRepository = templateRepository;
+    }
+
+    public async Task<EmailTemplate> GetAsync(
+        string serviceName,
+        string templateKey,
+        string? languageCode,
+        CancellationToken cancellationToken)
+    {
+        var lang = string.IsNullOrWhiteSpace(languageCode) ? "en" : languageCode;
+        var template = await _templateRepository.GetAsync(serviceName, templateKey, lang, cancellationToken);
+
+        if (template is null && lang != "en")
+            template = await _templateRepository.GetAsync(serviceName, templateKey, "en", cancellationToken);
+
+        return template
+            ?? throw new InvalidOperationException(
+                $"Template not found: service='{serviceName}' key='{templateKey}' language='{lang}'.");
+    }
+}

HrynCo.NotificationService.Worker.Services/EmailProcessing/IEmailTemplateRenderingService.cs

@@ -0,0 +1,9 @@
+using HrynCo.NotificationService.Contracts.Messages;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+public interface IEmailTemplateRenderingService
+{
+    RenderedEmail Render(EmailTemplate template, SendEmailMessageData data);
+}

HrynCo.NotificationService.Worker.Services/EmailProcessing/IEmailTemplateService.cs

@@ -0,0 +1,12 @@
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+public interface IEmailTemplateService
+{
+    Task<EmailTemplate> GetAsync(
+        string serviceName,
+        string templateKey,
+        string? languageCode,
+        CancellationToken cancellationToken);
+}

HrynCo.NotificationService.Worker.Services/EmailProcessing/ISendEmailService.cs

@@ -0,0 +1,8 @@
+using HrynCo.NotificationService.Contracts.Messages;
+
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+public interface ISendEmailService
+{
+    Task ProcessAsync(SendEmailMessage message, CancellationToken cancellationToken);
+}

HrynCo.NotificationService.Worker.Services/EmailProcessing/RenderedEmail.cs

@@ -1,3 +1,3 @@
-namespace HrynCo.NotificationService.Worker;
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
 
 public record RenderedEmail(string Subject, string HtmlBody, string TextBody);

HrynCo.NotificationService.Worker.Services/EmailProcessing/SendEmailService.cs

@@ -0,0 +1,198 @@
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+using System.Net;
+using System.Net.Mail;
+using System.Text;
+using HrynCo.NotificationService.Contracts.Messages;
+using HrynCo.NotificationService.DAL.Abstract.Providers;
+using HrynCo.NotificationService.DAL.Abstract.Repositories;
+using HrynCo.NotificationService.DAL.Abstract.Templates;
+using Hrynco.RabbitMq;
+using Microsoft.Extensions.Logging;
+
+internal sealed class SendEmailService : ISendEmailService
+{
+    private readonly IEmailChannelRepository _channelRepository;
+    private readonly IEmailChannelUsageRepository _usageRepository;
+    private readonly IEmailTemplateService _templateService;
+    private readonly IEmailTemplateRenderingService _templateRenderingService;
+    private readonly IRabbitMqPublisher _publisher;
+    private readonly ILogger<SendEmailService> _logger;
+
+    public SendEmailService(
+        IEmailChannelRepository channelRepository,
+        IEmailChannelUsageRepository usageRepository,
+        IEmailTemplateService templateService,
+        IEmailTemplateRenderingService templateRenderingService,
+        IRabbitMqPublisher publisher,
+        ILogger<SendEmailService> logger)
+    {
+        _channelRepository = channelRepository;
+        _usageRepository = usageRepository;
+        _templateService = templateService;
+        _templateRenderingService = templateRenderingService;
+        _publisher = publisher;
+        _logger = logger;
+    }
+
+    public async Task ProcessAsync(SendEmailMessage message, CancellationToken cancellationToken)
+    {
+        SendEmailMessageData data = message.Data;
+
+        _logger.LogInformation(
+            "Processing SendEmail for service={Service} template={Template} recipient={Recipient} [CorrelationId={CorrelationId}]",
+            data.ServiceName, data.TemplateKey, data.RecipientEmail, message.CorrelationContext?.CorrelationId);
+
+        EmailChannel channel = await ResolveChannelAsync(data.ServiceName, cancellationToken);
+        EmailTemplate template = await GetTemplateAsync(data, cancellationToken);
+
+        await EnforceLimitsAsync(channel, cancellationToken);
+
+        RenderedEmail rendered = _templateRenderingService.Render(template, data);
+
+        SmtpChannelSettings smtpChannel = channel.Settings as SmtpChannelSettings
+                                          ?? throw new InvalidOperationException(
+                                              $"Channel type '{channel.EmailChannelType}' is not supported for sending.");
+
+        try
+        {
+            using var client = new SmtpClient(smtpChannel.Host, smtpChannel.Port)
+            {
+                EnableSsl = smtpChannel.UseSsl,
+                Credentials = string.IsNullOrWhiteSpace(smtpChannel.Username)
+                    ? null
+                    : new NetworkCredential(smtpChannel.Username, smtpChannel.Password)
+            };
+
+            using var mail = new MailMessage
+            {
+                From = new MailAddress(smtpChannel.FromEmail, smtpChannel.FromName),
+                Subject = rendered.Subject,
+                Body = rendered.TextBody,
+                IsBodyHtml = false,
+                BodyEncoding = Encoding.UTF8,
+                SubjectEncoding = Encoding.UTF8
+            };
+
+            if (!string.IsNullOrWhiteSpace(rendered.HtmlBody))
+            {
+                var html = AlternateView.CreateAlternateViewFromString(
+                    rendered.HtmlBody, Encoding.UTF8, "text/html");
+                mail.AlternateViews.Add(html);
+            }
+
+            mail.To.Add(new MailAddress(data.RecipientEmail, data.RecipientName));
+
+            await client.SendMailAsync(mail, cancellationToken);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "SMTP send failed for channel {ChannelId}", channel.Id);
+            throw;
+        }
+
+        await _usageRepository.IncrementUsageAsync(
+            channel.Id,
+            DateOnly.FromDateTime(DateTime.UtcNow),
+            cancellationToken);
+
+        _logger.LogInformation(
+            "Email sent successfully service={Service} template={Template} recipient={Recipient}",
+            data.ServiceName, data.TemplateKey, data.RecipientEmail);
+
+        await PublishResultAsync(message.CorrelationContext, data, null, cancellationToken);
+    }
+
+    private async Task<EmailTemplate> GetTemplateAsync(SendEmailMessageData data, CancellationToken cancellationToken)
+    {
+        return await _templateService.GetAsync(
+            data.ServiceName,
+            data.TemplateKey,
+            data.LanguageCode,
+            cancellationToken);
+    }
+
+    private async Task<EmailChannel> ResolveChannelAsync(string serviceName, CancellationToken ct)
+    {
+        var channels = await _channelRepository.GetByServiceAsync(serviceName, ct);
+
+        return channels
+                   .Where(c => c.IsActive)
+                   .OrderBy(c => c.Priority)
+                   .FirstOrDefault()
+               ?? throw new InvalidOperationException(
+                   $"No active email channel found for service '{serviceName}'.");
+    }
+
+    private async Task EnforceLimitsAsync(EmailChannel channel, CancellationToken ct)
+    {
+        DateOnly today = DateOnly.FromDateTime(DateTime.UtcNow);
+
+        if (channel.DailyLimit.HasValue)
+        {
+            int daily = await _usageRepository.GetDailyCountAsync(channel.Id, today, ct);
+
+            if (daily >= channel.DailyLimit.Value)
+            {
+                throw new InvalidOperationException(
+                    $"Channel '{channel.Id}' daily limit of {channel.DailyLimit.Value} reached ({daily} sent today).");
+            }
+        }
+
+        if (channel.MonthlyLimit.HasValue)
+        {
+            int monthly = await _usageRepository.GetMonthlyCountAsync(channel.Id, today.Year, today.Month, ct);
+
+            if (monthly >= channel.MonthlyLimit.Value)
+            {
+                throw new InvalidOperationException(
+                    $"Channel '{channel.Id}' monthly limit of {channel.MonthlyLimit.Value} reached ({monthly} sent this month).");
+            }
+        }
+    }
+
+    private async Task PublishResultAsync(
+        CorrelationContext? correlationContext,
+        SendEmailMessageData data,
+        string? errorMessage,
+        CancellationToken ct)
+    {
+        string? replyTo = correlationContext?.ReplyTo;
+
+        if (string.IsNullOrWhiteSpace(replyTo))
+        {
+            return;
+        }
+
+        try
+        {
+            var result = new NotificationResultMessage
+            {
+                CorrelationContext = (correlationContext ?? new CorrelationContext
+                    {
+                        CorrelationId = Guid.NewGuid().ToString()
+                    }) with
+                    {
+                        ReplyTo = null
+                    },
+                Data = new NotificationResultData
+                {
+                    ServiceName = data.ServiceName,
+                    RecipientEmail = data.RecipientEmail,
+                    TemplateKey = data.TemplateKey,
+                    Timestamp = DateTimeOffset.UtcNow,
+                    ErrorMessage = errorMessage
+                }
+            };
+
+            await _publisher.PublishAsync(replyTo, result, ct);
+
+            _logger.LogDebug("Result published to reply queue '{Queue}' [CorrelationId={CorrelationId}]",
+                replyTo, correlationContext?.CorrelationId);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "Failed to publish notification result to reply queue '{Queue}'", replyTo);
+        }
+    }
+}

HrynCo.NotificationService.Worker.Services/HrynCo.NotificationService.Worker.Services.csproj

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net10.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <RootNamespace>HrynCo.NotificationService.Worker.Services</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="HrynCo.RabbitMq" />
+    <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" />
+    <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\HrynCo.NotificationService.Contracts\HrynCo.NotificationService.Contracts.csproj" />
+    <ProjectReference Include="..\HrynCo.NotificationService.DAL.Abstract\HrynCo.NotificationService.DAL.Abstract.csproj" />
+  </ItemGroup>
+
+</Project>

HrynCo.NotificationService.Worker.Services/ServiceCollectionExtensions.cs

@@ -0,0 +1,17 @@
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
+using Hrynco.RabbitMq;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace HrynCo.NotificationService.Worker.Services;
+
+public static class ServiceCollectionExtensions
+{
+    public static IServiceCollection AddNotificationWorkerServices(this IServiceCollection services)
+    {
+        services.AddSingleton<IRabbitMqPublisher, RabbitMqPublisher>();
+        services.AddScoped<IEmailTemplateService, EmailTemplateService>();
+        services.AddScoped<IEmailTemplateRenderingService, EmailTemplateRenderingService>();
+        services.AddScoped<ISendEmailService, SendEmailService>();
+        return services;
+    }
+}

HrynCo.NotificationService.Worker/Dockerfile

@@ -11,7 +11,7 @@ COPY ["Directory.Build.props", "."]
 COPY ["Directory.Packages.props", "."]
 COPY ["HrynCo.NotificationService.DAL.Abstract/HrynCo.NotificationService.DAL.Abstract.csproj", "HrynCo.NotificationService.DAL.Abstract/"]
 COPY ["HrynCo.NotificationService.DAL.EF/HrynCo.NotificationService.DAL.EF.csproj", "HrynCo.NotificationService.DAL.EF/"]
-COPY ["HrynCo.NotificationService.Services/HrynCo.NotificationService.Services.csproj", "HrynCo.NotificationService.Services/"]
+COPY ["HrynCo.NotificationService.Worker.Services/HrynCo.NotificationService.Worker.Services.csproj", "HrynCo.NotificationService.Worker.Services/"]
 COPY ["HrynCo.NotificationService.Worker/HrynCo.NotificationService.Worker.csproj", "HrynCo.NotificationService.Worker/"]
 
 RUN dotnet restore "HrynCo.NotificationService.Worker/HrynCo.NotificationService.Worker.csproj"

HrynCo.NotificationService.Worker/HrynCo.NotificationService.Worker.csproj

@@ -10,7 +10,6 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Hosting" />
     <PackageReference Include="HrynCo.RabbitMq" />
-    <PackageReference Include="MediatR" />
     <PackageReference Include="Serilog.Extensions.Hosting" />
     <PackageReference Include="Serilog.Settings.Configuration" />
     <PackageReference Include="Serilog.Sinks.Console" />
@@ -19,7 +18,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\HrynCo.NotificationService.Contracts\HrynCo.NotificationService.Contracts.csproj" />
-    <ProjectReference Include="..\HrynCo.NotificationService.Services\HrynCo.NotificationService.Services.csproj" />
     <ProjectReference Include="..\HrynCo.NotificationService.DAL.EF\HrynCo.NotificationService.DAL.EF.csproj" />
+    <ProjectReference Include="..\HrynCo.NotificationService.Worker.Services\HrynCo.NotificationService.Worker.Services.csproj" />
   </ItemGroup>
 </Project>

HrynCo.NotificationService.Worker/Program.cs

@@ -1,8 +1,7 @@
 using HrynCo.NotificationService.DAL.EF;
-using HrynCo.NotificationService.Services;
 using HrynCo.NotificationService.Worker;
+using HrynCo.NotificationService.Worker.Services;
 using Hrynco.RabbitMq;
-using Microsoft.Extensions.Options;
 
 var builder = Host.CreateApplicationBuilder(args);
 
@@ -14,7 +13,7 @@ var appSettings = builder.Configuration
 
 builder.Services.AddSingleton(appSettings);
 builder.Services.AddNotificationDataAccess(appSettings.ConnectionString);
-builder.Services.AddNotificationServices();
+builder.Services.AddNotificationWorkerServices();
 
 builder.Services.Configure<RabbitMqSettings>(
     builder.Configuration.GetSection($"{AppSettings.SectionName}:RabbitMq"));

HrynCo.NotificationService.Worker/SendEmailConsumer.cs

@@ -1,174 +1,32 @@
 namespace HrynCo.NotificationService.Worker;
 
-using System.Text;
-using System.Text.Json;
 using HrynCo.NotificationService.Contracts.Messages;
-using HrynCo.NotificationService.DAL.Abstract.Providers;
-using HrynCo.NotificationService.DAL.Abstract.Repositories;
-using HrynCo.NotificationService.DAL.Abstract.Templates;
-using HrynCo.NotificationService.Services.EmailChannels.Send;
 using Hrynco.RabbitMq;
-using MediatR;
+using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Options;
-using RabbitMQ.Client;
+using HrynCo.NotificationService.Worker.Services.EmailProcessing;
 
-public sealed class SendEmailConsumer(
-    IOptionsMonitor<RabbitMqSettings> options,
-    IEmailChannelRepository channelRepository,
-    IEmailTemplateRepository templateRepository,
-    IEmailChannelUsageRepository usageRepository,
-    IMediator mediator,
-    AppSettings appSettings,
-    ILogger<SendEmailConsumer> logger)
-    : RabbitMqConsumerBase<SendEmailMessage, SendEmailMessageData>(options, logger)
+public sealed class SendEmailConsumer : RabbitMqConsumerBase<SendEmailMessage, SendEmailMessageData>
 {
+    private readonly IServiceScopeFactory _scopeFactory;
+
+    public SendEmailConsumer(
+        IOptionsMonitor<RabbitMqSettings> options,
+        IServiceScopeFactory scopeFactory,
+        ILogger<SendEmailConsumer> logger)
+        : base(options, logger)
+    {
+        _scopeFactory = scopeFactory;
+    }
+
     private const string IncomingQueue = "notification.send-email";
 
     protected override string QueueName => IncomingQueue;
 
     protected override async Task HandleMessageAsync(SendEmailMessage message, CancellationToken cancellationToken)
     {
-        var data = message.Data;
-
-        logger.LogInformation(
-            "Processing SendEmail for service={Service} template={Template} recipient={Recipient} [CorrelationId={CorrelationId}]",
-            data.ServiceName, data.TemplateKey, data.RecipientEmail, message.CorrelationContext?.CorrelationId);
-
-        var channel = await ResolveChannelAsync(data.ServiceName, cancellationToken);
-        var template = await ResolveTemplateAsync(data.ServiceName, data.TemplateKey, data.LanguageCode, cancellationToken);
-
-        await EnforceLimitsAsync(channel, cancellationToken);
-
-        var rendered = RenderTemplate(template, data);
-
-        var sendResult = await mediator.Send(
-            new SendEmailCommand(channel.Id, data.RecipientEmail, data.RecipientName,
-                rendered.Subject, rendered.HtmlBody, rendered.TextBody),
-            cancellationToken);
-
-        if (!sendResult.IsSuccess)
-            throw new InvalidOperationException(sendResult.Error?.Message ?? "Send failed.");
-
-        logger.LogInformation(
-            "Email sent successfully service={Service} template={Template} recipient={Recipient}",
-            data.ServiceName, data.TemplateKey, data.RecipientEmail);
-
-        await PublishResultAsync(message.CorrelationContext, data, errorMessage: null, cancellationToken);
-    }
-
-    private async Task<EmailChannel> ResolveChannelAsync(string serviceName, CancellationToken ct)
-    {
-        var channels = await channelRepository.GetByServiceAsync(serviceName, ct);
-
-        return channels
-            .Where(c => c.IsActive)
-            .OrderBy(c => c.Priority)
-            .FirstOrDefault()
-            ?? throw new InvalidOperationException(
-                $"No active email channel found for service '{serviceName}'.");
-    }
-
-    private async Task<EmailTemplate> ResolveTemplateAsync(
-        string serviceName, string templateKey, string? languageCode, CancellationToken ct)
-    {
-        var lang = string.IsNullOrWhiteSpace(languageCode) ? "en" : languageCode;
-        var template = await templateRepository.GetAsync(serviceName, templateKey, lang, ct);
-
-        if (template is null && lang != "en")
-            template = await templateRepository.GetAsync(serviceName, templateKey, "en", ct);
-
-        return template
-            ?? throw new InvalidOperationException(
-                $"Template not found: service='{serviceName}' key='{templateKey}' language='{lang}'.");
-    }
-
-    private async Task EnforceLimitsAsync(EmailChannel channel, CancellationToken ct)
-    {
-        var today = DateOnly.FromDateTime(DateTime.UtcNow);
-
-        if (channel.DailyLimit.HasValue)
-        {
-            var daily = await usageRepository.GetDailyCountAsync(channel.Id, today, ct);
-            if (daily >= channel.DailyLimit.Value)
-                throw new InvalidOperationException(
-                    $"Channel '{channel.Id}' daily limit of {channel.DailyLimit.Value} reached ({daily} sent today).");
-        }
-
-        if (channel.MonthlyLimit.HasValue)
-        {
-            var monthly = await usageRepository.GetMonthlyCountAsync(channel.Id, today.Year, today.Month, ct);
-            if (monthly >= channel.MonthlyLimit.Value)
-                throw new InvalidOperationException(
-                    $"Channel '{channel.Id}' monthly limit of {channel.MonthlyLimit.Value} reached ({monthly} sent this month).");
-        }
-    }
-
-    private static RenderedEmail RenderTemplate(EmailTemplate template, SendEmailMessageData data)
-    {
-        return new RenderedEmail(
-            Interpolate(template.Subject, data.Variables),
-            Interpolate(template.HtmlBody, data.Variables),
-            Interpolate(template.TextBody, data.Variables));
-    }
-
-    private static string Interpolate(string text, IReadOnlyDictionary<string, string> variables)
-    {
-        var sb = new StringBuilder(text);
-        foreach (var (key, value) in variables)
-            sb.Replace($"{{{{{key}}}}}", value);
-        return sb.ToString();
-    }
-
-    private async Task PublishResultAsync(
-        CorrelationContext? correlationContext,
-        SendEmailMessageData data,
-        string? errorMessage,
-        CancellationToken ct)
-    {
-        var replyTo = correlationContext?.ReplyTo;
-        if (string.IsNullOrWhiteSpace(replyTo))
-            return;
-
-        try
-        {
-            var result = new NotificationResultMessage
-            {
-                CorrelationContext = (correlationContext ?? new CorrelationContext { CorrelationId = Guid.NewGuid().ToString() }) with { ReplyTo = null },
-                Data = new NotificationResultData
-                {
-                    ServiceName = data.ServiceName,
-                    RecipientEmail = data.RecipientEmail,
-                    TemplateKey = data.TemplateKey,
-                    Timestamp = DateTimeOffset.UtcNow,
-                    ErrorMessage = errorMessage
-                }
-            };
-
-            byte[] body = Encoding.UTF8.GetBytes(JsonSerializer.Serialize(result));
-
-            var factory = new ConnectionFactory
-            {
-                HostName = appSettings.RabbitMq.Host,
-                Port = appSettings.RabbitMq.Port,
-                UserName = appSettings.RabbitMq.User,
-                Password = appSettings.RabbitMq.Password,
-                VirtualHost = appSettings.RabbitMq.VirtualHost
-            };
-
-            await using var conn = await factory.CreateConnectionAsync(ct);
-            await using var ch = await conn.CreateChannelAsync(cancellationToken: ct);
-
-            await ch.QueueDeclareAsync(replyTo, durable: true, exclusive: false, autoDelete: false,
-                cancellationToken: ct);
-            await ch.BasicPublishAsync(exchange: string.Empty, routingKey: replyTo, body: body,
-                cancellationToken: ct);
-
-            logger.LogDebug("Result published to reply queue '{Queue}' [CorrelationId={CorrelationId}]",
-                replyTo, correlationContext?.CorrelationId);
-        }
-        catch (Exception ex)
-        {
-            logger.LogWarning(ex, "Failed to publish notification result to reply queue '{Queue}'", replyTo);
-        }
+        using var scope = _scopeFactory.CreateScope();
+        var service = scope.ServiceProvider.GetRequiredService<ISendEmailService>();
+        await service.ProcessAsync(message, cancellationToken);
     }
 }

HrynCo.NotificationService.Worker/appsettings.Development.json

@@ -1,4 +1,14 @@
 {
+  "App": {
+    "ConnectionString": "Host=192.168.2.121;Port=55435;Database=hrynco_ns_prod;Username=ns_user;Password=HAwS0c4A1QmH",
+    "RabbitMq": {
+      "Host": "192.168.2.121",
+      "Port": 5675,
+      "User": "ns_user",
+      "Password": "LN22mEWYdfCy",
+      "VirtualHost": "/"
+    }
+  },
   "Serilog": {
     "MinimumLevel": {
       "Default": "Debug",
@@ -7,6 +17,20 @@
         "Microsoft.EntityFrameworkCore": "Information",
         "Microsoft.AspNetCore": "Information"
       }
+    },
+    "WriteTo": [
+      { "Name": "Console" },
+      {
+        "Name": "Seq",
+        "Args": {
+          "serverUrl": "http://192.168.2.121:5341"
+        }
+      }
+    ],
+    "Enrich": [ "FromLogContext" ],
+    "Properties": {
+      "Application": "hrynco-notification-service-worker",
+      "Environment": "Development"
     }
   }
 }

HrynCo.NotificationService.slnx

@@ -20,5 +20,6 @@
   <Project Path="HrynCo.NotificationService.DAL.EF/HrynCo.NotificationService.DAL.EF.csproj" />
   <Project Path="HrynCo.NotificationService.Services.Tests/HrynCo.NotificationService.Services.Tests.csproj" />
   <Project Path="HrynCo.NotificationService.Services/HrynCo.NotificationService.Services.csproj" />
+  <Project Path="HrynCo.NotificationService.Worker.Services/HrynCo.NotificationService.Worker.Services.csproj" />
   <Project Path="HrynCo.NotificationService.Worker/HrynCo.NotificationService.Worker.csproj" />
 </Solution>

NuGet.Config

@@ -1,8 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <configuration>
-  <config>
-    <add key="globalPackagesFolder" value="%USERPROFILE%\.nuget\packages" />
-  </config>
   <packageSources>
     <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
   </packageSources>

README.md

@@ -1 +1,17 @@
 # hrynco-notification-service
+
+## Notification worker flow
+
+```mermaid
+flowchart TD
+    A[Worker host starts] --> B[Load config and register services]
+    B --> C[Start SendEmailConsumer]
+    C --> D[Receive message from notification.send-email]
+    D --> E[Resolve SendEmailService]
+    E --> F[Pick channel and template]
+    F --> G[Render email content]
+    G --> H[Send via SMTP]
+    H --> I[Update usage counters]
+    I --> J[Optionally publish result to reply queue]
+    H -. failure .-> K[Log and rethrow]
+```