Notification audit package - log sent notifications

README.md

@@ -18,6 +18,7 @@ This repository offers a wide collection of .NET packages for use in microservic
 - [Kubernetes Health Checks](#Health-Checks)
 - [NHibernate](#NHibernate)
 - [Notifications](#Notifications)
+- [Notifications Audit](#Notifications-Audit)
 
 ## RabbitMQ
 
@@ -319,4 +320,21 @@ public class YourNotificationRequestHandler(IEmailSender sender) : IRequestHandl
 ```
 
 > [!NOTE]
-> Note that attachment will be inlined only if its 'Inline' field is true and its name is referred as image source in message body.
+> Attachment will be added to notification only if:
+> - it is not inlined
+> - it is inlined and referred by name as image source in notification text
+
+### Notifications Audit
+
+To audit sent notifications, first install the [NuGet package](https://www.nuget.org/packages/Luxoft.Bss.Platform.Notifications.Audit):
+```shell
+dotnet add package Luxoft.Bss.Platform.Notifications.Audit
+```
+
+Then register notifications service in DI with provided sql connection
+```C#
+services
+    .AddPlatformNotificationsAudit(o => o.ConnectionString = builder.Configuration.GetConnectionString("DefaultConnection")!);
+```
+
+Thats all - db schema and tables will be generated on application start (you can customize schema and table names on DI step).

src/Bss.Platform.Api.Documentation/DependencyInjection.cs

@@ -6,6 +6,8 @@
 using Microsoft.Extensions.Hosting;
 using Microsoft.OpenApi.Models;
 
+using Swashbuckle.AspNetCore.SwaggerGen;
+
 namespace Bss.Platform.Api.Documentation;
 
 public static class DependencyInjection
@@ -15,7 +17,8 @@ public static class DependencyInjection
     public static IServiceCollection AddPlatformApiDocumentation(
         this IServiceCollection services,
         IWebHostEnvironment hostEnvironment,
-        string title = "API")
+        string title = "API",
+        Action<SwaggerGenOptions>? setupAction = null)
     {
         if (hostEnvironment.IsProduction())
         {
@@ -27,8 +30,8 @@ public static IServiceCollection AddPlatformApiDocumentation(
                .AddSwaggerGen(
                    x =>
                    {
-                       x.SchemaFilter<XEnumNamesSchemaFilter>();
                        x.SwaggerDoc("api", new OpenApiInfo { Title = title });
+                       x.SchemaFilter<XEnumNamesSchemaFilter>();
 
                        x.AddSecurityDefinition(
                            AuthorizationScheme,
@@ -52,6 +55,8 @@ public static IServiceCollection AddPlatformApiDocumentation(
                                    new List<string>()
                                }
                            });
+
+                       setupAction?.Invoke(x);
                    });
     }
 

src/Bss.Platform.Notifications.Audit/Bss.Platform.Notifications.Audit.csproj

@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk">
+    <PropertyGroup>
+        <PackageId>Luxoft.Bss.Platform.Notifications.Audit</PackageId>
+    </PropertyGroup>
+    <ItemGroup>
+        <ProjectReference Include="..\Bss.Platform.Notifications\Bss.Platform.Notifications.csproj"/>
+    </ItemGroup>
+    <ItemGroup>
+        <PackageReference Include="Dapper"/>
+        <PackageReference Include="Microsoft.SqlServer.SqlManagementObjects"/>
+    </ItemGroup>
+</Project>

src/Bss.Platform.Notifications.Audit/DependencyInjection.cs

@@ -0,0 +1,24 @@
+using Bss.Platform.Notifications.Audit.Models;
+using Bss.Platform.Notifications.Audit.Services;
+using Bss.Platform.Notifications.Interfaces;
+
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Options;
+
+namespace Bss.Platform.Notifications.Audit;
+
+public static class DependencyInjection
+{
+    public static IServiceCollection AddPlatformNotificationsAudit(
+        this IServiceCollection services,
+        Action<NotificationAuditOptions>? setup = null)
+    {
+        var settings = new NotificationAuditOptions();
+        setup?.Invoke(settings);
+
+        return services
+               .AddHostedService<AuditSchemaMigrationService>()
+               .AddScoped<IAuditService, AuditService>()
+               .AddSingleton<IOptions<NotificationAuditOptions>>(_ => Options.Create(settings));
+    }
+}

src/Bss.Platform.Notifications.Audit/Models/NotificationAuditOptions.cs

@@ -0,0 +1,10 @@
+namespace Bss.Platform.Notifications.Audit.Models;
+
+public class NotificationAuditOptions
+{
+    public string Schema { get; set; } = "notifications";
+
+    public string Table { get; set; } = "SentMessages";
+
+    public string ConnectionString { get; set; } = default!;
+}

src/Bss.Platform.Notifications.Audit/Services/AuditSchemaMigrationService.cs

@@ -0,0 +1,65 @@
+using Bss.Platform.Notifications.Audit.Models;
+
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using Microsoft.SqlServer.Management.Common;
+using Microsoft.SqlServer.Management.Smo;
+
+namespace Bss.Platform.Notifications.Audit.Services;
+
+public class AuditSchemaMigrationService(ILogger<AuditSchemaMigrationService> logger, IOptions<NotificationAuditOptions> settings)
+    : BackgroundService
+{
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        try
+        {
+            await using var connection = new SqlConnection(settings.Value.ConnectionString);
+            await connection.OpenAsync(stoppingToken);
+
+            var server = new Server(new ServerConnection(connection));
+            var catalog = server.ConnectionContext.CurrentDatabase;
+
+            if (string.IsNullOrWhiteSpace(catalog) || !server.Databases.Contains(catalog))
+            {
+                throw new ArgumentException("Initial catalog not provided or does not exist");
+            }
+
+            var database = server.Databases[catalog];
+
+            if (!database.Tables.Contains(settings.Value.Table, settings.Value.Schema))
+            {
+                if (!database.Schemas.Contains(settings.Value.Schema))
+                {
+                    logger.LogInformation("Creating schema [{Schema}] ...", settings.Value.Schema);
+                    server.ConnectionContext.ExecuteNonQuery($"CREATE SCHEMA [{settings.Value.Schema}]");
+                }
+
+                logger.LogInformation("Creating table [{Table}] ...", settings.Value.Table);
+                server.ConnectionContext.ExecuteNonQuery(
+                    $"""
+                     CREATE TABLE [{settings.Value.Schema}].[{settings.Value.Table}] (
+                                     [id] [uniqueidentifier] NOT NULL PRIMARY KEY,
+                                     [from] [nvarchar](255) NOT NULL,
+                                     [to] [nvarchar](max) NULL,
+                                     [copy] [nvarchar](max) NULL,
+                                     [replyTo] [nvarchar](max) NULL,
+                                     [subject] [nvarchar](max) NULL,
+                                     [message] [nvarchar](max) NULL,
+                                     [timestamp] [datetime2](7) NOT NULL)
+                     """);
+            }
+
+            await connection.CloseAsync();
+
+            logger.LogInformation("Schema migration successfully complete");
+        }
+        catch (Exception e)
+        {
+            logger.LogError(e, "Schema migration was failed");
+            throw;
+        }
+    }
+}

src/Bss.Platform.Notifications.Audit/Services/AuditService.cs

@@ -0,0 +1,47 @@
+using System.Net.Mail;
+
+using Bss.Platform.Notifications.Audit.Models;
+using Bss.Platform.Notifications.Interfaces;
+
+using Dapper;
+
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Bss.Platform.Notifications.Audit.Services;
+
+public class AuditService(ILogger<AuditService> logger, IOptions<NotificationAuditOptions> settings) : IAuditService
+{
+    private const string Sql = """
+                                   insert into [{0}].[{1}]
+                                       ([id], [from], [to], [copy], [replyTo], [subject], [message], [timestamp])
+                                   values
+                                       (newid(), @from, @to, @copy, @replyTo, @subject, @message, getdate())
+                               """;
+
+    public async Task LogAsync(MailMessage message, CancellationToken token)
+    {
+        try
+        {
+            await using var db = new SqlConnection(settings.Value.ConnectionString);
+            await db.OpenAsync(token);
+
+            await db.ExecuteAsync(
+                string.Format(Sql, settings.Value.Schema, settings.Value.Table),
+                new
+                {
+                    from = message.From!.Address,
+                    to = string.Join(";", message.To.Select(x => x.Address)),
+                    copy = string.Join(";", message.CC.Select(x => x.Address)),
+                    replyTo = string.Join(";", message.ReplyToList.Select(x => x.Address)),
+                    subject = message.Subject,
+                    message = message.Body
+                });
+        }
+        catch (Exception e)
+        {
+            logger.LogError(e, "Failed to log sent message");
+        }
+    }
+}

src/Bss.Platform.Notifications/DependencyInjection.cs

@@ -17,28 +17,27 @@ public static IServiceCollection AddPlatformNotifications(
     {
         var settings = configuration.GetSection(NotificationSenderOptions.SectionName).Get<NotificationSenderOptions>()!;
 
-        return AddTestEnvironmentRedirection(services, hostEnvironment, settings)
-               .AddMailMessageSenders(settings)
-               .Configure<NotificationSenderOptions>(configuration.GetSection(NotificationSenderOptions.SectionName))
-               .AddScoped<IEmailSender, EmailSender>();
+        return services.AddEmailSender(hostEnvironment, settings)
+                       .AddMailMessageSenders(settings)
+                       .Configure<NotificationSenderOptions>(configuration.GetSection(NotificationSenderOptions.SectionName));
     }
 
-    private static IServiceCollection AddTestEnvironmentRedirection(
+    private static IServiceCollection AddEmailSender(
         this IServiceCollection services,
         IHostEnvironment hostEnvironment,
         NotificationSenderOptions settings)
     {
         if (hostEnvironment.IsProduction())
         {
-            return services;
+            return services.AddScoped<IEmailSender, EmailSender>();
         }
 
         if (settings.RedirectTo?.Length == 0)
         {
             throw new ArgumentException("Test email address is not provided");
         }
 
-        return services.AddScoped<IRedirectService, RedirectService>();
+        return services.AddScoped<IEmailSender, EmailSenderTest>();
     }
 
     private static IServiceCollection AddMailMessageSenders(this IServiceCollection services, NotificationSenderOptions settings)

src/Bss.Platform.Notifications/Interfaces/IAuditService.cs

@@ -0,0 +1,8 @@
+using System.Net.Mail;
+
+namespace Bss.Platform.Notifications.Interfaces;
+
+public interface IAuditService
+{
+    Task LogAsync(MailMessage message, CancellationToken token);
+}

src/Bss.Platform.Notifications/Services/EmailSender.cs

@@ -6,23 +6,26 @@
 
 namespace Bss.Platform.Notifications.Services;
 
-internal class EmailSender(IEnumerable<IMailMessageSender> senders, IRedirectService? redirectService = null) : IEmailSender
+internal class EmailSender(IEnumerable<IMailMessageSender> senders, IAuditService? auditService = null) : IEmailSender
 {
-    public async Task<MailMessage> SendAsync(EmailModel model, CancellationToken token)
+    public async Task<MailMessage> SendAsync(EmailModel emailModel, CancellationToken token)
     {
-        var message = Convert(model);
-
-        redirectService?.Redirect(message);
+        var message = this.Convert(emailModel);
 
         foreach (var sender in senders)
         {
             await sender.SendAsync(message, token);
         }
 
+        if (auditService is not null)
+        {
+            await auditService.LogAsync(message, token);
+        }
+
         return message;
     }
 
-    private static MailMessage Convert(EmailModel model)
+    protected virtual MailMessage Convert(EmailModel model)
     {
         var mailMessage = new MailMessage { Subject = model.Subject, Body = model.Body, From = model.From, IsBodyHtml = true };
 
@@ -50,9 +53,9 @@ private static void SetAttachments(Attachment[] attachments, MailMessage mailMes
     {
         foreach (var attachment in attachments)
         {
-            mailMessage.Attachments.Add(attachment);
             if (!attachment.ContentDisposition!.Inline)
             {
+                mailMessage.Attachments.Add(attachment);
                 continue;
             }
 
@@ -63,6 +66,7 @@ private static void SetAttachments(Attachment[] attachments, MailMessage mailMes
             }
 
             mailMessage.Body = Regex.Replace(mailMessage.Body, srcRegex, $"src=\"cid:{attachment.ContentId}\"", RegexOptions.IgnoreCase);
+            mailMessage.Attachments.Add(attachment);
         }
     }
 

src/Bss.Platform.Notifications/Services/RedirectService.cs → src/Bss.Platform.Notifications/Services/EmailSenderTest.cs

@@ -7,9 +7,21 @@
 
 namespace Bss.Platform.Notifications.Services;
 
-internal class RedirectService(IOptions<NotificationSenderOptions> settings) : IRedirectService
+internal class EmailSenderTest(
+    IEnumerable<IMailMessageSender> senders,
+    IOptions<NotificationSenderOptions> settings,
+    IAuditService? auditService = null)
+    : EmailSender(senders, auditService)
 {
-    public void Redirect(MailMessage message)
+    protected override MailMessage Convert(EmailModel model)
+    {
+        var message = base.Convert(model);
+        this.ChangeRecipients(message);
+
+        return message;
+    }
+
+    private void ChangeRecipients(MailMessage message)
     {
         AddRecipientsToBody(message);
 
@@ -21,14 +33,6 @@ public void Redirect(MailMessage message)
         }
     }
 
-    private static void ClearRecipients(MailMessage message)
-    {
-        message.To.Clear();
-        message.CC.Clear();
-        message.Bcc.Clear();
-        message.ReplyToList.Clear();
-    }
-
     private static void AddRecipientsToBody(MailMessage message)
     {
         var originalRecipients =
@@ -39,4 +43,12 @@ private static void AddRecipientsToBody(MailMessage message)
 
         message.Body = $"{originalRecipients}{message.Body}";
     }
+
+    private static void ClearRecipients(MailMessage message)
+    {
+        message.To.Clear();
+        message.CC.Clear();
+        message.Bcc.Clear();
+        message.ReplyToList.Clear();
+    }
 }