Add user registration emails + email infrastructure (#150)

* Add email functionality

* Add email template project and rendering service

* Update email template dir structure

* Add email header and footer components for user registration template

* update example env

* Refactor email templates namespace and components

* Format email dir

src/Core/API/API.Core/API.Core.csproj

@@ -20,7 +20,12 @@
   <ItemGroup>
     <ProjectReference Include="..\..\Domain.Entities\Domain.Entities.csproj" />
     <ProjectReference Include="..\..\Domain.Exceptions\Domain.Exceptions.csproj" />
-    <ProjectReference Include="..\..\Infrastructure\Infrastructure.Repository\Infrastructure.Repository.csproj" />
+    <ProjectReference
+      Include="..\..\Infrastructure\Infrastructure.Email\Infrastructure.Email.csproj" />
+    <ProjectReference
+      Include="..\..\Infrastructure\Infrastructure.Email.Templates\Infrastructure.Email.Templates.csproj" />
+    <ProjectReference
+      Include="..\..\Infrastructure\Infrastructure.Repository\Infrastructure.Repository.csproj" />
     <ProjectReference Include="..\..\Infrastructure\Infrastructure.Jwt\Infrastructure.Jwt.csproj" />
     <ProjectReference Include="..\..\Service\Service.Auth\Service.Auth.csproj" />
     <ProjectReference Include="..\..\Service\Service.UserManagement\Service.UserManagement.csproj" />

src/Core/API/API.Core/Dockerfile

@@ -14,6 +14,7 @@ COPY ["Domain.Exceptions/Domain.Exceptions.csproj", "Domain.Exceptions/"]
 COPY ["Infrastructure/Infrastructure.Repository/Infrastructure.Repository.csproj", "Infrastructure/Infrastructure.Repository/"]
 COPY ["Infrastructure/Infrastructure.Jwt/Infrastructure.Jwt.csproj", "Infrastructure/Infrastructure.Jwt/"]
 COPY ["Infrastructure/Infrastructure.PasswordHashing/Infrastructure.PasswordHashing.csproj", "Infrastructure/Infrastructure.PasswordHashing/"]
+COPY ["Infrastructure/Infrastructure.Email/Infrastructure.Email.csproj", "Infrastructure/Infrastructure.Email/"]
 COPY ["Service/Service.Auth/Service.Auth.csproj", "Service/Service.Auth/"]
 COPY ["Service/Service.UserManagement/Service.UserManagement.csproj", "Service/Service.UserManagement/"]
 RUN dotnet restore "API/API.Core/API.Core.csproj"

src/Core/API/API.Core/Program.cs

@@ -12,6 +12,9 @@ using Microsoft.AspNetCore.Mvc.Filters;
 using Service.Auth.Auth;
 using Service.UserManagement.User;
 using API.Core.Contracts.Common;
+using Infrastructure.Email;
+using Infrastructure.Email.Templates;
+using Infrastructure.Email.Templates.Rendering;
 
 var builder = WebApplication.CreateBuilder(args);
 
@@ -53,6 +56,8 @@ builder.Services.AddScoped<IRegisterService, RegisterService>();
 
 builder.Services.AddScoped<ITokenInfrastructure, JwtInfrastructure>();
 builder.Services.AddScoped<IPasswordInfrastructure, Argon2Infrastructure>();
+builder.Services.AddScoped<IEmailProvider, SmtpEmailProvider>();
+builder.Services.AddScoped<IEmailTemplateProvider, EmailTemplateProvider>();
 
 // Register the exception filter
 builder.Services.AddScoped<GlobalExceptionFilter>();

src/Core/API/API.Specs/API.Specs.csproj

@@ -17,7 +17,8 @@
     <!-- Reqnroll core, xUnit adapter and code-behind generator -->
     <PackageReference Include="Reqnroll" Version="3.3.3" />
     <PackageReference Include="Reqnroll.xUnit" Version="3.3.3" />
-    <PackageReference Include="Reqnroll.Tools.MsBuild.Generation" Version="3.3.3" PrivateAssets="all" />
+    <PackageReference Include="Reqnroll.Tools.MsBuild.Generation" Version="3.3.3"
+      PrivateAssets="all" />
 
     <!-- ASP.NET Core integration testing -->
     <PackageReference Include="Microsoft.AspNetCore.Mvc.Testing" Version="9.0.1" />
@@ -34,5 +35,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\API.Core\API.Core.csproj" />
+    <ProjectReference
+      Include="..\..\Infrastructure\Infrastructure.Email\Infrastructure.Email.csproj" />
   </ItemGroup>
 </Project>

src/Core/API/API.Specs/Dockerfile

@@ -8,6 +8,7 @@ COPY ["Domain.Exceptions/Domain.Exceptions.csproj", "Domain.Exceptions/"]
 COPY ["Infrastructure/Infrastructure.Repository/Infrastructure.Repository.csproj", "Infrastructure/Infrastructure.Repository/"]
 COPY ["Infrastructure/Infrastructure.Jwt/Infrastructure.Jwt.csproj", "Infrastructure/Infrastructure.Jwt/"]
 COPY ["Infrastructure/Infrastructure.PasswordHashing/Infrastructure.PasswordHashing.csproj", "Infrastructure/Infrastructure.PasswordHashing/"]
+COPY ["Infrastructure/Infrastructure.Email/Infrastructure.Email.csproj", "Infrastructure/Infrastructure.Email/"]
 COPY ["Service/Service.Auth/Service.Auth.csproj", "Service/Service.Auth/"]
 COPY ["Service/Service.UserManagement/Service.UserManagement.csproj", "Service/Service.UserManagement/"]
 RUN dotnet restore "API/API.Specs/API.Specs.csproj"

src/Core/API/API.Specs/Mocks/MockEmailService.cs

@@ -0,0 +1,54 @@
+using Infrastructure.Email;
+
+namespace API.Specs.Mocks;
+
+/// <summary>
+/// Mock email service for testing that doesn't actually send emails.
+/// Tracks sent emails for verification in tests if needed.
+/// </summary>
+public class MockEmailProvider : IEmailProvider
+{
+   public List<SentEmail> SentEmails { get; } = new();
+
+   public Task SendAsync(string to, string subject, string body, bool isHtml = true)
+   {
+      SentEmails.Add(new SentEmail
+      {
+         To = [to],
+         Subject = subject,
+         Body = body,
+         IsHtml = isHtml,
+         SentAt = DateTime.UtcNow
+      });
+
+      return Task.CompletedTask;
+   }
+
+   public Task SendAsync(IEnumerable<string> to, string subject, string body, bool isHtml = true)
+   {
+      SentEmails.Add(new SentEmail
+      {
+         To = to.ToList(),
+         Subject = subject,
+         Body = body,
+         IsHtml = isHtml,
+         SentAt = DateTime.UtcNow
+      });
+
+      return Task.CompletedTask;
+   }
+
+   public void Clear()
+   {
+      SentEmails.Clear();
+   }
+
+   public class SentEmail
+   {
+      public List<string> To { get; init; } = new();
+      public string Subject { get; init; } = string.Empty;
+      public string Body { get; init; } = string.Empty;
+      public bool IsHtml { get; init; }
+      public DateTime SentAt { get; init; }
+   }
+}

src/Core/API/API.Specs/TestApiFactory.cs

@@ -1,7 +1,10 @@
 using System.Collections.Generic;
+using API.Specs.Mocks;
+using Infrastructure.Email;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Mvc.Testing;
 using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace API.Specs
 {
@@ -10,6 +13,20 @@ namespace API.Specs
         protected override void ConfigureWebHost(IWebHostBuilder builder)
         {
             builder.UseEnvironment("Testing");
+
+            builder.ConfigureServices(services =>
+            {
+                // Replace the real email service with mock for testing
+                var descriptor = services.SingleOrDefault(
+                    d => d.ServiceType == typeof(IEmailProvider));
+
+                if (descriptor != null)
+                {
+                    services.Remove(descriptor);
+                }
+
+                services.AddScoped<IEmailProvider, MockEmailProvider>();
+            });
         }
     }
 }