refactor: modularize email processing logic and improve service structure

- 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.
2026-05-14 22:15:15 +03:00
parent 0861e18cec
commit 25fb48ccf0
18 changed files with 394 additions and 174 deletions
@@ -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();
+    }
+}
@@ -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}'.");
+    }
+}
@@ -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);
+}
@@ -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);
+}
@@ -0,0 +1,8 @@
+using HrynCo.NotificationService.Contracts.Messages;
+
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+public interface ISendEmailService
+{
+    Task ProcessAsync(SendEmailMessage message, CancellationToken cancellationToken);
+}
@@ -0,0 +1,3 @@
+namespace HrynCo.NotificationService.Worker.Services.EmailProcessing;
+
+public record RenderedEmail(string Subject, string HtmlBody, string TextBody);
@@ -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);
+        }
+    }
+}
@@ -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>
@@ -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;
+    }
+}