[FA-10] Adds user service and authentication service

FictionArchive.Service.AuthenticationService/Controllers/AuthenticationWebhookController.cs

@@ -0,0 +1,36 @@
+using FictionArchive.Service.AuthenticationService.Models.Requests;
+using FictionArchive.Service.AuthenticationService.Models.IntegrationEvents;
+using FictionArchive.Service.Shared.Services.EventBus;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Mvc;
+
+namespace FictionArchive.Service.AuthenticationService.Controllers
+{
+    [Route("api/[controller]")]
+    [ApiController]
+    public class AuthenticationWebhookController : ControllerBase
+    {
+        private readonly IEventBus _eventBus;
+
+        public AuthenticationWebhookController(IEventBus eventBus)
+        {
+            _eventBus = eventBus;
+        }
+
+        [HttpPost(nameof(UserRegistered))]
+        public async Task<ActionResult> UserRegistered([FromBody] UserRegisteredWebhookPayload payload)
+        {
+            var authUserAddedEvent = new AuthUserAddedEvent
+            {
+                OAuthProviderId = payload.OAuthProviderId,
+                InviterOAuthProviderId = payload.InviterOAuthProviderId,
+                EventUserEmail = payload.EventUserEmail,
+                EventUserUsername = payload.EventUserUsername
+            };
+
+            await _eventBus.Publish(authUserAddedEvent);
+
+            return Ok();
+        }
+    }
+}

FictionArchive.Service.AuthenticationService/Dockerfile

@@ -0,0 +1,23 @@
+FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS base
+USER $APP_UID
+WORKDIR /app
+EXPOSE 8080
+EXPOSE 8081
+
+FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
+ARG BUILD_CONFIGURATION=Release
+WORKDIR /src
+COPY ["FictionArchive.Service.AuthenticationService/FictionArchive.Service.AuthenticationService.csproj", "FictionArchive.Service.AuthenticationService/"]
+RUN dotnet restore "FictionArchive.Service.AuthenticationService/FictionArchive.Service.AuthenticationService.csproj"
+COPY . .
+WORKDIR "/src/FictionArchive.Service.AuthenticationService"
+RUN dotnet build "./FictionArchive.Service.AuthenticationService.csproj" -c $BUILD_CONFIGURATION -o /app/build
+
+FROM build AS publish
+ARG BUILD_CONFIGURATION=Release
+RUN dotnet publish "./FictionArchive.Service.AuthenticationService.csproj" -c $BUILD_CONFIGURATION -o /app/publish /p:UseAppHost=false
+
+FROM base AS final
+WORKDIR /app
+COPY --from=publish /app/publish .
+ENTRYPOINT ["dotnet", "FictionArchive.Service.AuthenticationService.dll"]

FictionArchive.Service.AuthenticationService/FictionArchive.Service.AuthenticationService.csproj

@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+    <PropertyGroup>
+        <TargetFramework>net8.0</TargetFramework>
+        <Nullable>enable</Nullable>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <DockerDefaultTargetOS>Linux</DockerDefaultTargetOS>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="8.0.7" />
+        <PackageReference Include="Swashbuckle.AspNetCore" Version="6.6.2"/>
+    </ItemGroup>
+
+    <ItemGroup>
+      <Content Include="..\.dockerignore">
+        <Link>.dockerignore</Link>
+      </Content>
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\FictionArchive.Service.Shared\FictionArchive.Service.Shared.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <Folder Include="Controllers\" />
+    </ItemGroup>
+
+</Project>

FictionArchive.Service.AuthenticationService/FictionArchive.Service.AuthenticationService.http

@@ -0,0 +1,6 @@
+@FictionArchive.Service.AuthenticationService_HostAddress = http://localhost:5091
+
+GET {{FictionArchive.Service.AuthenticationService_HostAddress}}/weatherforecast/
+Accept: application/json
+
+###

FictionArchive.Service.AuthenticationService/Models/IntegrationEvents/AuthUserAddedEvent.cs

@@ -0,0 +1,16 @@
+using FictionArchive.Service.Shared.Services.EventBus;
+
+namespace FictionArchive.Service.AuthenticationService.Models.IntegrationEvents;
+
+public class AuthUserAddedEvent : IIntegrationEvent
+{
+    public string OAuthProviderId { get; set; }
+    
+    public string InviterOAuthProviderId { get; set; }
+
+    // The email of the user that created the event
+    public string EventUserEmail { get; set; }
+
+    // The username of the user that created the event
+    public string EventUserUsername { get; set; }
+}

FictionArchive.Service.AuthenticationService/Models/Requests/UserRegisteredWebhookPayload.cs

@@ -0,0 +1,17 @@
+namespace FictionArchive.Service.AuthenticationService.Models.Requests;
+
+public class UserRegisteredWebhookPayload
+{
+    // The body of the notification message
+    public string Body { get; set; }
+    
+    public string OAuthProviderId { get; set; }
+    
+    public string InviterOAuthProviderId { get; set; }
+
+    // The email of the user that created the event
+    public string EventUserEmail { get; set; }
+
+    // The username of the user that created the event
+    public string EventUserUsername { get; set; }
+}

FictionArchive.Service.AuthenticationService/Program.cs

@@ -0,0 +1,49 @@
+using FictionArchive.Service.Shared;
+using FictionArchive.Service.Shared.Services.EventBus.Implementations;
+
+namespace FictionArchive.Service.AuthenticationService;
+
+public class Program
+{
+    public static void Main(string[] args)
+    {
+        var builder = WebApplication.CreateBuilder(args);
+
+        // Add services to the container.
+
+        builder.Services.AddControllers();
+        // Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
+        builder.Services.AddEndpointsApiExplorer();
+        builder.Services.AddSwaggerGen();
+
+        #region Event Bus
+
+        builder.Services.AddRabbitMQ(opt =>
+        {
+            builder.Configuration.GetSection("RabbitMQ").Bind(opt);
+        });
+        
+        #endregion
+
+        builder.Services.AddHealthChecks();
+        
+        var app = builder.Build();
+
+        // Configure the HTTP request pipeline.
+        if (app.Environment.IsDevelopment())
+        {
+            app.UseSwagger();
+            app.UseSwaggerUI();
+        }
+
+        app.UseHttpsRedirection();
+
+        app.MapHealthChecks("/healthz");
+        
+        app.UseAuthorization();
+        
+        app.MapControllers();
+
+        app.Run();
+    }
+}

FictionArchive.Service.AuthenticationService/Properties/launchSettings.json

@@ -0,0 +1,41 @@
+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:23522",
+      "sslPort": 44397
+    }
+  },
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "applicationUrl": "http://localhost:5091",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "applicationUrl": "https://localhost:7223;http://localhost:5091",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "launchUrl": "swagger",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

FictionArchive.Service.AuthenticationService/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

FictionArchive.Service.AuthenticationService/appsettings.json

@@ -0,0 +1,13 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "RabbitMQ": {
+    "ConnectionString": "amqp://localhost",
+    "ClientIdentifier": "AuthenticationService"
+  },
+  "AllowedHosts": "*"
+}

FictionArchive.Service.NovelService/Models/IntegrationEvents/ChapterPullRequestedEvent.cs

@@ -2,7 +2,7 @@ using FictionArchive.Service.Shared.Services.EventBus;
 
 namespace FictionArchive.Service.NovelService.Models.IntegrationEvents;
 
-public class ChapterPullRequestedEvent : IntegrationEvent
+public class ChapterPullRequestedEvent : IIntegrationEvent
 {
     public uint NovelId { get; set; }
     public uint ChapterNumber { get; set; }

FictionArchive.Service.NovelService/Models/IntegrationEvents/NovelUpdateRequestedEvent.cs

@@ -2,7 +2,7 @@ using FictionArchive.Service.Shared.Services.EventBus;
 
 namespace FictionArchive.Service.NovelService.Models.IntegrationEvents;
 
-public class NovelUpdateRequestedEvent : IntegrationEvent
+public class NovelUpdateRequestedEvent : IIntegrationEvent
 {
     public string NovelUrl { get; set; }
 }

FictionArchive.Service.NovelService/Models/IntegrationEvents/TranslationRequestCompletedEvent.cs

@@ -3,7 +3,7 @@ using FictionArchive.Service.Shared.Services.EventBus;
 
 namespace FictionArchive.Service.NovelService.Models.IntegrationEvents;
 
-public class TranslationRequestCompletedEvent : IntegrationEvent
+public class TranslationRequestCompletedEvent : IIntegrationEvent
 {
     /// <summary>
     /// Maps this event back to a triggering request.

FictionArchive.Service.NovelService/Models/IntegrationEvents/TranslationRequestCreatedEvent.cs

@@ -3,7 +3,7 @@ using FictionArchive.Service.Shared.Services.EventBus;
 
 namespace FictionArchive.Service.NovelService.Models.IntegrationEvents;
 
-public class TranslationRequestCreatedEvent : IntegrationEvent
+public class TranslationRequestCreatedEvent : IIntegrationEvent
 {
     public Guid TranslationRequestId { get; set; }
     public Language From { get; set; }

FictionArchive.Service.Shared/Services/EventBus/EventBusBuilder.cs

@@ -16,7 +16,7 @@ public class EventBusBuilder<TEventBus> where TEventBus : class, IEventBus
         _services.AddSingleton<SubscriptionManager>(_subscriptionManager);
     }
 
-    public EventBusBuilder<TEventBus> Subscribe<TEvent, TEventHandler>() where TEvent : IntegrationEvent where TEventHandler : class, IIntegrationEventHandler<TEvent>
+    public EventBusBuilder<TEventBus> Subscribe<TEvent, TEventHandler>() where TEvent : IIntegrationEvent where TEventHandler : class, IIntegrationEventHandler<TEvent>
     {
         _services.AddKeyedTransient<IIntegrationEventHandler, TEventHandler>(typeof(TEvent).Name);
         _subscriptionManager.RegisterSubscription<TEvent>();

FictionArchive.Service.Shared/Services/EventBus/IEventBus.cs

@@ -2,6 +2,6 @@ namespace FictionArchive.Service.Shared.Services.EventBus;
 
 public interface IEventBus
 {
-    Task Publish<TEvent>(TEvent integrationEvent) where TEvent : IntegrationEvent;
+    Task Publish<TEvent>(TEvent integrationEvent) where TEvent : IIntegrationEvent;
     Task Publish(object integrationEvent, string eventType);
 }

FictionArchive.Service.Shared/Services/EventBus/IIntegrationEvent.cs

@@ -0,0 +1,7 @@
+using NodaTime;
+
+namespace FictionArchive.Service.Shared.Services.EventBus;
+
+public interface IIntegrationEvent
+{
+}

FictionArchive.Service.Shared/Services/EventBus/IIntegrationEventHandler.cs

@@ -1,12 +1,12 @@
 namespace FictionArchive.Service.Shared.Services.EventBus;
 
-public interface IIntegrationEventHandler<in TEvent> : IIntegrationEventHandler where TEvent : IntegrationEvent
+public interface IIntegrationEventHandler<in TEvent> : IIntegrationEventHandler where TEvent : IIntegrationEvent
 {
     Task Handle(TEvent @event);
-    Task IIntegrationEventHandler.Handle(IntegrationEvent @event) => Handle((TEvent)@event);
+    Task IIntegrationEventHandler.Handle(IIntegrationEvent @event) => Handle((TEvent)@event);
 }
 
 public interface IIntegrationEventHandler
 {
-    Task Handle(IntegrationEvent @event);
+    Task Handle(IIntegrationEvent @event);
 }

FictionArchive.Service.Shared/Services/EventBus/Implementations/RabbitMQEventBus.cs

@@ -22,6 +22,8 @@ public class RabbitMQEventBus : IEventBus, IHostedService
     private readonly JsonSerializerSettings _jsonSerializerSettings;
 
     private const string ExchangeName = "fiction-archive-event-bus";
+    private const string CreatedAtHeader = "X-Created-At";
+    private const string EventIdHeader = "X-Event-Id";
 
     public RabbitMQEventBus(IServiceScopeFactory serviceScopeFactory, RabbitMQConnectionProvider connectionProvider, IOptions<RabbitMQOptions> options, SubscriptionManager subscriptionManager, ILogger<RabbitMQEventBus> logger)
     {
@@ -33,14 +35,10 @@ public class RabbitMQEventBus : IEventBus, IHostedService
         _jsonSerializerSettings = new JsonSerializerSettings().ConfigureForNodaTime(DateTimeZoneProviders.Tzdb);
     }
 
-    public async Task Publish<TEvent>(TEvent integrationEvent) where TEvent : IntegrationEvent
+    public async Task Publish<TEvent>(TEvent integrationEvent) where TEvent : IIntegrationEvent
     {
         var routingKey = typeof(TEvent).Name;
         
-        // Set integration event values
-        integrationEvent.CreatedAt = Instant.FromDateTimeUtc(DateTime.UtcNow);
-        integrationEvent.EventId = Guid.NewGuid();
-        
         await Publish(integrationEvent, routingKey);
     }
 
@@ -48,7 +46,16 @@ public class RabbitMQEventBus : IEventBus, IHostedService
     {
         var channel = await _connectionProvider.GetDefaultChannelAsync();
         var body = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(integrationEvent));
-        await channel.BasicPublishAsync(ExchangeName, eventType, true, body);
+        
+        // headers
+        var props = new BasicProperties();
+        props.Headers = new Dictionary<string, object?>()
+        {
+            { CreatedAtHeader, Instant.FromDateTimeUtc(DateTime.UtcNow).ToString() },
+            { EventIdHeader, Guid.NewGuid().ToString() }
+        };
+        
+        await channel.BasicPublishAsync(ExchangeName, eventType, true, props, body);
         _logger.LogInformation("Published event {EventName}", eventType);
     }
 
@@ -70,6 +77,8 @@ public class RabbitMQEventBus : IEventBus, IHostedService
                     return OnReceivedEvent(sender, @event, channel);
                 };
                 
+                await channel.BasicConsumeAsync(_options.ClientIdentifier, false, consumer, cancellationToken: cancellationToken);
+                
                 foreach (var subscription in _subscriptionManager.Subscriptions)
                 {
                     await channel.QueueBindAsync(_options.ClientIdentifier, ExchangeName, subscription.Key,
@@ -77,8 +86,6 @@ public class RabbitMQEventBus : IEventBus, IHostedService
                     _logger.LogInformation("Subscribed to {SubscriptionKey}", subscription.Key);
                 }
 
-                await channel.BasicConsumeAsync(_options.ClientIdentifier, false, consumer, cancellationToken: cancellationToken);
-
                 _logger.LogInformation("RabbitMQ EventBus started.");
             }
             catch (Exception e)
@@ -106,7 +113,7 @@ public class RabbitMQEventBus : IEventBus, IHostedService
             }
             
             var eventBody = Encoding.UTF8.GetString(@event.Body.Span);
-            var eventObject = JsonConvert.DeserializeObject(eventBody, _subscriptionManager.Subscriptions[eventName], _jsonSerializerSettings) as IntegrationEvent;
+            var eventObject = JsonConvert.DeserializeObject(eventBody, _subscriptionManager.Subscriptions[eventName], _jsonSerializerSettings) as IIntegrationEvent;
             
             using var scope = _serviceScopeFactory.CreateScope();
 

FictionArchive.Service.Shared/Services/EventBus/IntegrationEvent.cs

@@ -1,9 +0,0 @@
-using NodaTime;
-
-namespace FictionArchive.Service.Shared.Services.EventBus;
-
-public abstract class IntegrationEvent
-{
-    public Guid EventId { get; set; }
-    public Instant CreatedAt { get; set; }
-}

FictionArchive.Service.TranslationService/Models/IntegrationEvents/TranslationRequestCompletedEvent.cs

@@ -4,7 +4,7 @@ using FictionArchive.Service.TranslationService.Models.Enums;
 
 namespace FictionArchive.Service.TranslationService.Models.IntegrationEvents;
 
-public class TranslationRequestCompletedEvent : IntegrationEvent
+public class TranslationRequestCompletedEvent : IIntegrationEvent
 {
     /// <summary>
     /// Maps this event back to a triggering request.

FictionArchive.Service.TranslationService/Models/IntegrationEvents/TranslationRequestCreatedEvent.cs

@@ -3,7 +3,7 @@ using FictionArchive.Service.Shared.Services.EventBus;
 
 namespace FictionArchive.Service.TranslationService.Models.IntegrationEvents;
 
-public class TranslationRequestCreatedEvent : IntegrationEvent
+public class TranslationRequestCreatedEvent : IIntegrationEvent
 {
     public Guid TranslationRequestId { get; set; }
     public Language From { get; set; }

FictionArchive.Service.UserService/Dockerfile

@@ -0,0 +1,23 @@
+FROM mcr.microsoft.com/dotnet/aspnet:8.0 AS base
+USER $APP_UID
+WORKDIR /app
+EXPOSE 8080
+EXPOSE 8081
+
+FROM mcr.microsoft.com/dotnet/sdk:8.0 AS build
+ARG BUILD_CONFIGURATION=Release
+WORKDIR /src
+COPY ["FictionArchive.Service.UserService/FictionArchive.Service.UserService.csproj", "FictionArchive.Service.UserService/"]
+RUN dotnet restore "FictionArchive.Service.UserService/FictionArchive.Service.UserService.csproj"
+COPY . .
+WORKDIR "/src/FictionArchive.Service.UserService"
+RUN dotnet build "./FictionArchive.Service.UserService.csproj" -c $BUILD_CONFIGURATION -o /app/build
+
+FROM build AS publish
+ARG BUILD_CONFIGURATION=Release
+RUN dotnet publish "./FictionArchive.Service.UserService.csproj" -c $BUILD_CONFIGURATION -o /app/publish /p:UseAppHost=false
+
+FROM base AS final
+WORKDIR /app
+COPY --from=publish /app/publish .
+ENTRYPOINT ["dotnet", "FictionArchive.Service.UserService.dll"]

FictionArchive.Service.UserService/FictionArchive.Service.UserService.csproj

@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+    <PropertyGroup>
+        <TargetFramework>net8.0</TargetFramework>
+        <Nullable>enable</Nullable>
+        <ImplicitUsings>enable</ImplicitUsings>
+        <DockerDefaultTargetOS>Linux</DockerDefaultTargetOS>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <Content Include="..\.dockerignore">
+        <Link>.dockerignore</Link>
+      </Content>
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\FictionArchive.Service.Shared\FictionArchive.Service.Shared.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="Microsoft.EntityFrameworkCore.Design" Version="9.0.11">
+        <PrivateAssets>all</PrivateAssets>
+        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      </PackageReference>
+    </ItemGroup>
+
+</Project>

FictionArchive.Service.UserService/GraphQL/Mutation.cs

@@ -0,0 +1,13 @@
+using FictionArchive.Service.UserService.Models.Database;
+using FictionArchive.Service.UserService.Services;
+
+namespace FictionArchive.Service.UserService.GraphQL;
+
+public class Mutation
+{
+    public async Task<User> RegisterUser(string username, string email, string oAuthProviderId,
+        string? inviterOAuthProviderId, UserManagementService userManagementService)
+    {
+        return await userManagementService.RegisterUser(username, email, oAuthProviderId, inviterOAuthProviderId);
+    }
+}

FictionArchive.Service.UserService/GraphQL/Query.cs

@@ -0,0 +1,12 @@
+using FictionArchive.Service.UserService.Models.Database;
+using FictionArchive.Service.UserService.Services;
+
+namespace FictionArchive.Service.UserService.GraphQL;
+
+public class Query
+{
+    public async Task<IQueryable<User>> GetUsers(UserManagementService userManagementService)
+    {
+        return userManagementService.GetUsers();
+    }
+}

FictionArchive.Service.UserService/Migrations/20251122034145_Initial.Designer.cs

@@ -0,0 +1,77 @@
+// <auto-generated />
+using System;
+using FictionArchive.Service.UserService.Services;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using NodaTime;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace FictionArchive.Service.UserService.Migrations
+{
+    [DbContext(typeof(UserServiceDbContext))]
+    [Migration("20251122034145_Initial")]
+    partial class Initial
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "9.0.11")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("FictionArchive.Service.UserService.Models.Database.User", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<Instant>("CreatedTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<bool>("Disabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("Email")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<Guid?>("InviterId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Instant>("LastUpdatedTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("OAuthProviderId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("InviterId");
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("FictionArchive.Service.UserService.Models.Database.User", b =>
+                {
+                    b.HasOne("FictionArchive.Service.UserService.Models.Database.User", "Inviter")
+                        .WithMany()
+                        .HasForeignKey("InviterId");
+
+                    b.Navigation("Inviter");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

FictionArchive.Service.UserService/Migrations/20251122034145_Initial.cs

@@ -0,0 +1,51 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+using NodaTime;
+
+#nullable disable
+
+namespace FictionArchive.Service.UserService.Migrations
+{
+    /// <inheritdoc />
+    public partial class Initial : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "Users",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "uuid", nullable: false),
+                    Username = table.Column<string>(type: "text", nullable: false),
+                    Email = table.Column<string>(type: "text", nullable: false),
+                    OAuthProviderId = table.Column<string>(type: "text", nullable: false),
+                    Disabled = table.Column<bool>(type: "boolean", nullable: false),
+                    InviterId = table.Column<Guid>(type: "uuid", nullable: true),
+                    CreatedTime = table.Column<Instant>(type: "timestamp with time zone", nullable: false),
+                    LastUpdatedTime = table.Column<Instant>(type: "timestamp with time zone", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_Users", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_Users_Users_InviterId",
+                        column: x => x.InviterId,
+                        principalTable: "Users",
+                        principalColumn: "Id");
+                });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_Users_InviterId",
+                table: "Users",
+                column: "InviterId");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "Users");
+        }
+    }
+}

FictionArchive.Service.UserService/Migrations/20251122040724_UniqueOAuthProviderId.Designer.cs

@@ -0,0 +1,80 @@
+// <auto-generated />
+using System;
+using FictionArchive.Service.UserService.Services;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using NodaTime;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace FictionArchive.Service.UserService.Migrations
+{
+    [DbContext(typeof(UserServiceDbContext))]
+    [Migration("20251122040724_UniqueOAuthProviderId")]
+    partial class UniqueOAuthProviderId
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "9.0.11")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("FictionArchive.Service.UserService.Models.Database.User", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<Instant>("CreatedTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<bool>("Disabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("Email")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<Guid?>("InviterId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Instant>("LastUpdatedTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("OAuthProviderId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("InviterId");
+
+                    b.HasIndex("OAuthProviderId")
+                        .IsUnique();
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("FictionArchive.Service.UserService.Models.Database.User", b =>
+                {
+                    b.HasOne("FictionArchive.Service.UserService.Models.Database.User", "Inviter")
+                        .WithMany()
+                        .HasForeignKey("InviterId");
+
+                    b.Navigation("Inviter");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

FictionArchive.Service.UserService/Migrations/20251122040724_UniqueOAuthProviderId.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace FictionArchive.Service.UserService.Migrations
+{
+    /// <inheritdoc />
+    public partial class UniqueOAuthProviderId : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateIndex(
+                name: "IX_Users_OAuthProviderId",
+                table: "Users",
+                column: "OAuthProviderId",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropIndex(
+                name: "IX_Users_OAuthProviderId",
+                table: "Users");
+        }
+    }
+}

FictionArchive.Service.UserService/Migrations/UserServiceDbContextModelSnapshot.cs

@@ -0,0 +1,77 @@
+// <auto-generated />
+using System;
+using FictionArchive.Service.UserService.Services;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using NodaTime;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace FictionArchive.Service.UserService.Migrations
+{
+    [DbContext(typeof(UserServiceDbContext))]
+    partial class UserServiceDbContextModelSnapshot : ModelSnapshot
+    {
+        protected override void BuildModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "9.0.11")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("FictionArchive.Service.UserService.Models.Database.User", b =>
+                {
+                    b.Property<Guid>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("uuid");
+
+                    b.Property<Instant>("CreatedTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<bool>("Disabled")
+                        .HasColumnType("boolean");
+
+                    b.Property<string>("Email")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<Guid?>("InviterId")
+                        .HasColumnType("uuid");
+
+                    b.Property<Instant>("LastUpdatedTime")
+                        .HasColumnType("timestamp with time zone");
+
+                    b.Property<string>("OAuthProviderId")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasColumnType("text");
+
+                    b.HasKey("Id");
+
+                    b.HasIndex("InviterId");
+
+                    b.HasIndex("OAuthProviderId")
+                        .IsUnique();
+
+                    b.ToTable("Users");
+                });
+
+            modelBuilder.Entity("FictionArchive.Service.UserService.Models.Database.User", b =>
+                {
+                    b.HasOne("FictionArchive.Service.UserService.Models.Database.User", "Inviter")
+                        .WithMany()
+                        .HasForeignKey("InviterId");
+
+                    b.Navigation("Inviter");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

FictionArchive.Service.UserService/Models/Database/User.cs

@@ -0,0 +1,20 @@
+using FictionArchive.Service.Shared.Models;
+using Microsoft.EntityFrameworkCore;
+
+namespace FictionArchive.Service.UserService.Models.Database;
+
+[Index(nameof(OAuthProviderId), IsUnique = true)]
+public class User : BaseEntity<Guid>
+{
+    public string Username { get; set; }
+    public string Email { get; set; }
+    public string OAuthProviderId { get; set; }
+    
+    
+    public bool Disabled { get; set; }
+    
+    /// <summary>
+    /// The user that generated an invite used by this user.
+    /// </summary>
+    public User? Inviter { get; set; }
+}

FictionArchive.Service.UserService/Models/IntegrationEvents/AuthUserAddedEvent.cs

@@ -0,0 +1,16 @@
+using FictionArchive.Service.Shared.Services.EventBus;
+
+namespace FictionArchive.Service.UserService.Models.IntegrationEvents;
+
+public class AuthUserAddedEvent : IIntegrationEvent
+{
+    public string OAuthProviderId { get; set; }
+    
+    public string InviterOAuthProviderId { get; set; }
+
+    // The email of the user that created the event
+    public string EventUserEmail { get; set; }
+
+    // The username of the user that created the event
+    public string EventUserUsername { get; set; }
+}

FictionArchive.Service.UserService/Program.cs

@@ -0,0 +1,52 @@
+using FictionArchive.Service.Shared.Extensions;
+using FictionArchive.Service.Shared.Services.EventBus.Implementations;
+using FictionArchive.Service.UserService.GraphQL;
+using FictionArchive.Service.UserService.Models.IntegrationEvents;
+using FictionArchive.Service.UserService.Services;
+using FictionArchive.Service.UserService.Services.EventHandlers;
+
+namespace FictionArchive.Service.UserService;
+
+public class Program
+{
+    public static void Main(string[] args)
+    {
+        var builder = WebApplication.CreateBuilder(args);
+        
+        #region Event Bus
+
+        builder.Services.AddRabbitMQ(opt =>
+        {
+            builder.Configuration.GetSection("RabbitMQ").Bind(opt);
+        })
+        .Subscribe<AuthUserAddedEvent, AuthUserAddedEventHandler>();
+        
+        #endregion
+        
+        #region GraphQL
+        
+        builder.Services.AddDefaultGraphQl<Query, Mutation>();
+        
+        #endregion
+        
+        builder.Services.RegisterDbContext<UserServiceDbContext>(builder.Configuration.GetConnectionString("DefaultConnection"));
+        builder.Services.AddTransient<UserManagementService>();
+
+        builder.Services.AddHealthChecks();
+        
+        var app = builder.Build();
+        
+        // Update database
+        using (var scope = app.Services.CreateScope())
+        {
+            var dbContext = scope.ServiceProvider.GetRequiredService<UserServiceDbContext>();
+            dbContext.UpdateDatabase();
+        }
+        
+        app.MapGraphQL();
+        
+        app.MapHealthChecks("/healthz");
+
+        app.Run();
+    }
+}

FictionArchive.Service.UserService/Properties/launchSettings.json

@@ -0,0 +1,39 @@
+{
+  "$schema": "http://json.schemastore.org/launchsettings.json",
+  "iisSettings": {
+    "windowsAuthentication": false,
+    "anonymousAuthentication": true,
+    "iisExpress": {
+      "applicationUrl": "http://localhost:20480",
+      "sslPort": 44309
+    }
+  },
+  "profiles": {
+    "http": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "applicationUrl": "http://localhost:5145",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "https": {
+      "commandName": "Project",
+      "dotnetRunMessages": true,
+      "launchBrowser": true,
+      "launchUrl": "graphql",
+      "applicationUrl": "https://localhost:7157;http://localhost:5145",
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    },
+    "IIS Express": {
+      "commandName": "IISExpress",
+      "launchBrowser": true,
+      "environmentVariables": {
+        "ASPNETCORE_ENVIRONMENT": "Development"
+      }
+    }
+  }
+}

FictionArchive.Service.UserService/Services/EventHandlers/AuthUserAddedEventHandler.cs

@@ -0,0 +1,23 @@
+using FictionArchive.Service.Shared.Services.EventBus;
+using FictionArchive.Service.UserService.Models.IntegrationEvents;
+using FictionArchive.Service.UserService.Models.Database;
+using Microsoft.EntityFrameworkCore; // Add this line to include the UserModel
+
+namespace FictionArchive.Service.UserService.Services.EventHandlers;
+
+public class AuthUserAddedEventHandler : IIntegrationEventHandler<AuthUserAddedEvent>
+{
+    private readonly UserManagementService _userManagementService;
+    private readonly ILogger<AuthUserAddedEventHandler> _logger;
+
+    public AuthUserAddedEventHandler(UserServiceDbContext dbContext, ILogger<AuthUserAddedEventHandler> logger, UserManagementService userManagementService)
+    {
+        _logger = logger;
+        _userManagementService = userManagementService;
+    }
+
+    public async Task Handle(AuthUserAddedEvent @event)
+    {
+        await _userManagementService.RegisterUser(@event.EventUserUsername, @event.EventUserEmail, @event.OAuthProviderId, @event.InviterOAuthProviderId);
+    }
+}

FictionArchive.Service.UserService/Services/UserManagementService.cs

@@ -0,0 +1,45 @@
+using FictionArchive.Service.UserService.Models.Database;
+using Microsoft.EntityFrameworkCore;
+
+namespace FictionArchive.Service.UserService.Services;
+
+public class UserManagementService
+{
+    private readonly ILogger<UserManagementService> _logger;
+    private readonly UserServiceDbContext _dbContext;
+
+    public UserManagementService(UserServiceDbContext dbContext, ILogger<UserManagementService> logger)
+    {
+        _dbContext = dbContext;
+        _logger = logger;
+    }
+
+    public async Task<User> RegisterUser(string username, string email, string oAuthProviderId,
+        string? inviterOAuthProviderId)
+    {
+        var newUser = new User();
+        User? inviter =
+            await _dbContext.Users.FirstOrDefaultAsync(user => user.OAuthProviderId == inviterOAuthProviderId);
+        if (inviter == null && inviterOAuthProviderId != null)
+        {
+            _logger.LogCritical(
+                "A user with OAuthProviderId {OAuthProviderId} was marked as having inviter with OAuthProviderId {inviterOAuthProviderId}, but no user was found with that value.",
+                inviterOAuthProviderId, inviterOAuthProviderId);
+            newUser.Disabled = true;
+        }
+
+        newUser.Username = username;
+        newUser.Email = email;
+        newUser.OAuthProviderId = oAuthProviderId;
+
+        _dbContext.Users.Add(newUser); // Add the new user to the DbContext
+        await _dbContext.SaveChangesAsync(); // Save changes to the database
+        
+        return newUser;
+    }
+
+    public IQueryable<User> GetUsers()
+    {
+        return _dbContext.Users.AsQueryable();
+    }
+}

FictionArchive.Service.UserService/Services/UserServiceDbContext.cs

@@ -0,0 +1,14 @@
+using FictionArchive.Service.Shared.Services.Database;
+using FictionArchive.Service.UserService.Models.Database;
+using Microsoft.EntityFrameworkCore;
+
+namespace FictionArchive.Service.UserService.Services;
+
+public class UserServiceDbContext : FictionArchiveDbContext
+{
+    public DbSet<User> Users { get; set; }
+    
+    public UserServiceDbContext(DbContextOptions options, ILogger<UserServiceDbContext> logger) : base(options, logger)
+    {
+    }
+}

FictionArchive.Service.UserService/appsettings.Development.json

@@ -0,0 +1,8 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  }
+}

FictionArchive.Service.UserService/appsettings.json

@@ -0,0 +1,16 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Information",
+      "Microsoft.AspNetCore": "Warning"
+    }
+  },
+  "ConnectionStrings": {
+    "DefaultConnection": "Host=localhost;Database=FictionArchive_UserService;Username=postgres;password=postgres"
+  },
+  "RabbitMQ": {
+    "ConnectionString": "amqp://localhost",
+    "ClientIdentifier": "UserService"
+  },
+  "AllowedHosts": "*"
+}

FictionArchive.sln

@@ -12,6 +12,15 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FictionArchive.Service.Shar
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FictionArchive.Service.SchedulerService", "FictionArchive.Service.SchedulerService\FictionArchive.Service.SchedulerService.csproj", "{6813A8AD-A071-4F86-B227-BC4A5BCD7F3C}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FictionArchive.Service.UserService", "FictionArchive.Service.UserService\FictionArchive.Service.UserService.csproj", "{EE4D4795-2F79-4614-886D-AF8DA77120AC}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "FictionArchive.Service.AuthenticationService", "FictionArchive.Service.AuthenticationService\FictionArchive.Service.AuthenticationService.csproj", "{70C4AE82-B01E-421D-B590-C0F47E63CD0C}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{35C67E32-A17F-4EAB-B141-88AFCE11FF9C}"
+	ProjectSection(SolutionItems) = preProject
+		compose.yaml = compose.yaml
+	EndProjectSection
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -42,5 +51,13 @@ Global
 		{6813A8AD-A071-4F86-B227-BC4A5BCD7F3C}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{6813A8AD-A071-4F86-B227-BC4A5BCD7F3C}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{6813A8AD-A071-4F86-B227-BC4A5BCD7F3C}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EE4D4795-2F79-4614-886D-AF8DA77120AC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EE4D4795-2F79-4614-886D-AF8DA77120AC}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EE4D4795-2F79-4614-886D-AF8DA77120AC}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EE4D4795-2F79-4614-886D-AF8DA77120AC}.Release|Any CPU.Build.0 = Release|Any CPU
+		{70C4AE82-B01E-421D-B590-C0F47E63CD0C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{70C4AE82-B01E-421D-B590-C0F47E63CD0C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{70C4AE82-B01E-421D-B590-C0F47E63CD0C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{70C4AE82-B01E-421D-B590-C0F47E63CD0C}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal