Add mediator

src/backend/server/src/Todo.Api/Controllers/TodosController.cs

@@ -1,4 +1,5 @@
 using System.ComponentModel.DataAnnotations;
+using System.Security.Claims;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Todo.Core.Interfaces.Persistence;
@@ -17,8 +18,14 @@ public class TodosController : ControllerBase
     }
 
     [HttpPost]
-    public async Task<ActionResult<Core.Entities.Todo>> CreateTodo([FromBody] CreateTodoRequest request) =>
-        Ok(await _todoRepository.CreateTodoAsync(request.Title, String.Empty));
+    [Authorize]
+    public async Task<ActionResult<Core.Entities.Todo>> CreateTodo([FromBody] CreateTodoRequest request)
+    {
+        var userId = User.FindFirstValue("sub") ??
+                     throw new InvalidOperationException("Could not get user, something has gone terribly wrong");
+        
+        return Ok(await _todoRepository.CreateTodoAsync(request.Title, String.Empty, userId));
+    }
 
     [HttpGet]
     [Authorize]

src/backend/server/src/Todo.Api/Hubs/TodoHub.cs

@@ -1,11 +1,15 @@
 using System.Collections.Concurrent;
 using System.Security.Claims;
 using System.Text.Json;
+using MediatR;
 using Microsoft.AspNetCore.Authorization;
-using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.SignalR;
 using Todo.Api.Hubs.Models;
+using Todo.Core.Application.Commands.Todo;
+using Todo.Core.Application.Services.UserConnectionStore;
 using Todo.Core.Interfaces.Persistence;
+using Todo.Core.Interfaces.User;
+using Todo.Infrastructure;
 
 namespace Todo.Api.Hubs;
 
@@ -13,85 +17,59 @@ namespace Todo.Api.Hubs;
 public class TodoHub : Hub
 {
     private readonly ITodoRepository _todoRepository;
-
-    private static readonly ConcurrentDictionary<string, List<string>> ConnectedUsers = new();
+    private readonly IUserConnectionStore _userConnectionStore;
+    private readonly ICurrentUserService _currentUserService;
+    private readonly IMediator _mediator;
 
     public override Task OnConnectedAsync()
     {
-        var userId = Context.User.FindFirstValue("sub");
-
-        // Try to get a List of existing user connections from the cache
-        ConnectedUsers.TryGetValue(userId, out var existingUserConnectionIds);
-
-        // happens on the very first connection from the user
-        existingUserConnectionIds ??= new List<string>();
-
-        // First add to a List of existing user connections (i.e. multiple web browser tabs)
-        existingUserConnectionIds.Add(Context.ConnectionId);
-
-
-        // Add to the global dictionary of connected users
-        ConnectedUsers.TryAdd(userId, existingUserConnectionIds);
-
+        var userId = _currentUserService.GetUserId();
+        if (userId is not null)
+            _userConnectionStore.AddAsync(userId, Context.ConnectionId);
         return base.OnConnectedAsync();
     }
 
     public override Task OnDisconnectedAsync(Exception? exception)
     {
-        var userId = Context.User.FindFirstValue("sub");
-
-        ConnectedUsers.TryGetValue(userId, out var existingUserConnectionIds);
-
-        // remove the connection id from the List 
-        existingUserConnectionIds?.Remove(Context.ConnectionId);
-
-        // If there are no connection ids in the List, delete the user from the global cache (ConnectedUsers).
-        if (existingUserConnectionIds?.Count == 0)
-        {
-            // if there are no connections for the user,
-            // just delete the userName key from the ConnectedUsers concurent dictionary
-            ConnectedUsers.TryRemove(userId, out _);
-        }
+        var userId = _currentUserService.GetUserId();
+        if (userId is not null)
+            _userConnectionStore.RemoveAsync(userId, Context.ConnectionId);
 
         return base.OnDisconnectedAsync(exception);
     }
 
-
-    public TodoHub(ITodoRepository todoRepository)
+    public TodoHub(
+        ITodoRepository todoRepository,
+        IUserConnectionStore userConnectionStore,
+        ICurrentUserService currentUserService,
+        IMediator mediator)
     {
         _todoRepository = todoRepository;
+        _userConnectionStore = userConnectionStore;
+        _currentUserService = currentUserService;
+        _mediator = mediator;
     }
 
-    public async Task CreateTodo(string todoTitle, string projectName)
+    public async Task CreateTodo(string todoTitle, string? projectName)
     {
         if (todoTitle is null)
             throw new ArgumentException("title cannot be null");
-        var _ = await _todoRepository.CreateTodoAsync(todoTitle, projectName);
 
-        var todos = await _todoRepository.GetNotDoneTodos();
-        var serializedTodos =
-            JsonSerializer.Serialize(todos
-                .Select(t => new TodoResponse { Id = t.Id, Title = t.Title, Project = t.Project })
-                .ToList());
+        //var userId = GetUserId();
 
-        await RunOnUserConnections(async (connections) =>
-            await Clients.Clients(connections).SendAsync("getInboxTodos", serializedTodos));
+        //var _ = await _todoRepository.CreateTodoAsync(todoTitle, projectName, userId);
+        await _mediator.Send(new CreateTodoCommand(todoTitle, projectName));
+
+        await GetInboxTodos();
     }
 
 
     public async Task UpdateTodo(string todoId, bool todoStatus)
     {
-        await _todoRepository.UpdateTodoStatus(todoId, todoStatus);
+        var userId = GetUserId();
+        await _todoRepository.UpdateTodoStatus(todoId, todoStatus, userId);
 
-        var todos = await _todoRepository.GetNotDoneTodos();
-        var serializedTodos =
-            JsonSerializer.Serialize(todos
-                .Select(t => new TodoResponse
-                    { Id = t.Id, Title = t.Title, Status = t.Status, Project = t.Project })
-                .ToList());
-
-        await RunOnUserConnections(async (connections) =>
-            await Clients.Clients(connections).SendAsync("getInboxTodos", serializedTodos));
+        await GetInboxTodos();
     }
 
     public async Task GetTodos()
@@ -157,17 +135,15 @@ public class TodoHub : Hub
             await Clients.Clients(connections).SendAsync("getTodo", serializedTodo));
     }
 
-    private Task RunOnUserConnections(Func<IEnumerable<string>, Task> action)
+    private async Task RunOnUserConnections(Func<IEnumerable<string>, Task> action)
     {
-        var userId = Context.User.FindFirstValue("sub");
-        if (userId is null)
-            throw new InvalidOperationException("User id was invalid. Something has gone terribly wrong");
+        var userId = GetUserId();
+        var connections = await _userConnectionStore.GetConnectionsAsync(userId);
 
-        ConnectedUsers.TryGetValue(userId, out var connections);
-
-        if (connections is not null)
-            action(connections);
-
-        return Task.CompletedTask;
+        await action(connections);
     }
+
+    private string GetUserId() =>
+        _currentUserService.GetUserId() ??
+        throw new InvalidOperationException("User id was invalid. Something has gone terribly wrong");
 }

src/backend/server/src/Todo.Api/Publishers/TodoPublisher.cs

@@ -0,0 +1,42 @@
+using System.Threading;
+using Microsoft.AspNetCore.SignalR;
+using Microsoft.Extensions.Logging;
+using Todo.Api.Hubs;
+using Todo.Core.Application.Services.UserConnectionStore;
+using Todo.Core.Interfaces.Publisher;
+using Todo.Core.Interfaces.User;
+
+namespace Todo.Api.Publishers;
+
+public class TodoPublisher : ITodoPublisher
+{
+    private readonly IHubContext<TodoHub> _hubContext;
+    private readonly ICurrentUserService _currentUserService;
+    private readonly IUserConnectionStore _userConnectionStore;
+    private readonly ILogger<TodoPublisher> _logger;
+
+    public TodoPublisher(
+        IHubContext<TodoHub> hubContext,
+            ICurrentUserService currentUserService,
+            IUserConnectionStore userConnectionStore,
+        ILogger<TodoPublisher> logger)
+    {
+        _hubContext = hubContext;
+        _currentUserService = currentUserService;
+        _userConnectionStore = userConnectionStore;
+        _logger = logger;
+    }
+    
+    public async Task Publish(string todoId, CancellationToken cancellationToken)
+    {
+            var userId = _currentUserService.GetUserId() ?? throw new InvalidOperationException("Cannot proceed without user");
+            var connections = await _userConnectionStore.GetConnectionsAsync(userId);
+            
+            await _hubContext
+                .Clients
+                .Clients(connections)
+                .SendAsync("todoCreated", todoId , cancellationToken);
+            
+            _logger.LogInformation("todo created {TodoId}", todoId);
+    }
+}

src/backend/server/src/Todo.Api/Services/HttpContextCurrentUserService.cs

@@ -0,0 +1,17 @@
+using System.Security.Claims;
+using Microsoft.AspNetCore.Http;
+using Todo.Core.Interfaces.User;
+
+namespace Todo.Api.Services;
+
+public class HttpContextCurrentUserService : ICurrentUserService
+{
+    private readonly IHttpContextAccessor _httpContextAccessor;
+
+    public HttpContextCurrentUserService(IHttpContextAccessor httpContextAccessor)
+    {
+        _httpContextAccessor = httpContextAccessor;
+    }
+    
+    public string? GetUserId() => _httpContextAccessor.HttpContext?.User.FindFirstValue("sub");
+}

src/backend/server/src/Todo.Api/Startup.cs

@@ -8,9 +8,14 @@ using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Hosting;
 using Microsoft.OpenApi.Models;
 using Todo.Api.Hubs;
+using Todo.Api.Publishers;
+using Todo.Api.Services;
+using Todo.Core.Interfaces.User;
 using Todo.Infrastructure;
 using Todo.Persistence;
 using Todo.Persistence.Mongo;
+using Todo.Core;
+using Todo.Core.Interfaces.Publisher;
 
 namespace Todo.Api
 {
@@ -37,6 +42,10 @@ namespace Todo.Api
                         .AllowAnyMethod());
             });
 
+            services.AddCore();
+            services.AddScoped<ICurrentUserService, HttpContextCurrentUserService>();
+            services.AddScoped<ITodoPublisher, TodoPublisher>();
+
             services.AddSwaggerGen(c =>
             {
                 c.SwaggerDoc("v1", new OpenApiInfo { Title = "Todo.Api", Version = "v1" });

src/backend/server/src/Todo.Core/Application/Commands/Todo/CreateTodoCommand.cs

@@ -0,0 +1,37 @@
+using System.Threading;
+using MediatR;
+using Todo.Core.Application.Notifications.Todo;
+using Todo.Core.Interfaces.Persistence;
+using Todo.Core.Interfaces.User;
+
+namespace Todo.Core.Application.Commands.Todo;
+
+public record CreateTodoCommand(string TodoTitle, string? TodoProject) : IRequest<string>
+{
+    internal class Handler : IRequestHandler<CreateTodoCommand, string>
+    {
+        private readonly ICurrentUserService _currentUserService;
+        private readonly ITodoRepository _todoRepository;
+        private readonly IMediator _mediator;
+
+        public Handler(ICurrentUserService currentUserService, ITodoRepository todoRepository, IMediator mediator)
+        {
+            _currentUserService = currentUserService;
+            _todoRepository = todoRepository;
+            _mediator = mediator;
+        }
+
+        public async Task<string> Handle(CreateTodoCommand request, CancellationToken cancellationToken)
+        {
+            var userId = _currentUserService.GetUserId();
+            if (userId is null)
+                throw new InvalidOperationException("User was not found");
+
+            var todo = await _todoRepository.CreateTodoAsync(request.TodoTitle, request.TodoProject, userId);
+
+            await _mediator.Publish(new TodoCreated(todo.Id), cancellationToken);
+
+            return todo.Id;
+        }
+    }
+}

src/backend/server/src/Todo.Core/Application/Notifications/Todo/TodoCreated.cs

@@ -0,0 +1,28 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using System.Threading;
+using MediatR;
+using Microsoft.AspNetCore.SignalR;
+using Todo.Core.Application.Services.UserConnectionStore;
+using Todo.Core.Interfaces.Publisher;
+using Todo.Core.Interfaces.User;
+
+namespace Todo.Core.Application.Notifications.Todo;
+
+public record TodoCreated([property: JsonPropertyName("todoId")] string TodoId) : INotification
+{
+    internal class Handler : INotificationHandler<TodoCreated>
+    {
+        private readonly ITodoPublisher _todoPublisher;
+
+        public Handler(ITodoPublisher todoPublisher)
+        {
+            _todoPublisher = todoPublisher;
+        }
+
+        public async Task Handle(TodoCreated notification, CancellationToken cancellationToken)
+        {
+            await _todoPublisher.Publish(JsonSerializer.Serialize(notification), cancellationToken);
+        }
+    }
+}

src/backend/server/src/Todo.Core/Application/Publisher/ITodoPublisher.cs

@@ -0,0 +1,8 @@
+using System.Threading;
+
+namespace Todo.Core.Interfaces.Publisher;
+
+public interface ITodoPublisher
+{
+    Task Publish(string todoId, CancellationToken cancellationToken = new ());
+}

src/backend/server/src/Todo.Core/Application/Services/UserConnectionStore/IUserConnectionStore.cs

@@ -0,0 +1,8 @@
+namespace Todo.Core.Application.Services.UserConnectionStore;
+
+public interface IUserConnectionStore
+{
+    Task AddAsync(string userId, string connectionId);
+    Task RemoveAsync(string userId, string connectionId);
+    Task<IEnumerable<string>> GetConnectionsAsync(string userId);
+}

src/backend/server/src/Todo.Core/DependencyInjection.cs

@@ -2,9 +2,13 @@ global using System;
 global using System.Linq;
 global using System.Threading.Tasks;
 global using System.Collections.Generic;
+using System.Reflection;
+using MediatR;
+using Microsoft.Extensions.DependencyInjection;
 
 namespace Todo.Core;
 
 public static class DependencyInjection
 {
+    public static IServiceCollection AddCore(this IServiceCollection services) => services.AddMediatR(Assembly.GetExecutingAssembly());
 }

src/backend/server/src/Todo.Core/Interfaces/Persistence/ITodoRepository.cs

@@ -3,9 +3,9 @@ namespace Todo.Core.Interfaces.Persistence;
 
 public interface ITodoRepository
 {
-    Task<Entities.Todo> CreateTodoAsync(string title, string projectName);
+    Task<Entities.Todo> CreateTodoAsync(string title, string projectName, string userId);
     Task<IEnumerable<Entities.Todo>> GetTodosAsync();
-    Task UpdateTodoStatus(string todoId, bool todoStatus);
+    Task UpdateTodoStatus(string todoId, bool todoStatus, string userId);
     Task<IEnumerable<Entities.Todo>> GetNotDoneTodos();
     Task<Entities.Todo> GetTodoByIdAsync(string todoId);
     Task<Entities.Todo> UpdateTodoAsync(Entities.Todo todo);

src/backend/server/src/Todo.Core/Interfaces/Persistence/IUserRepository.cs

@@ -4,5 +4,5 @@ namespace Todo.Core.Interfaces.Persistence;
 
 public interface IUserRepository
 {
-    Task<User> Register(string email, string password);
+    Task<Entities.User> Register(string email, string password);
 }

src/backend/server/src/Todo.Core/Interfaces/User/ICurrentUserService.cs

@@ -0,0 +1,6 @@
+namespace Todo.Core.Interfaces.User;
+
+public interface ICurrentUserService
+{
+    string? GetUserId();
+}

src/backend/server/src/Todo.Core/Todo.Core.csproj

@@ -2,6 +2,20 @@
 
     <PropertyGroup>
         <TargetFramework>net6.0</TargetFramework>
+        <Nullable>enable</Nullable>
     </PropertyGroup>
     
+    <ItemGroup>
+        <FrameworkReference Include="Microsoft.AspNetCore.App" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <Folder Include="Application\Services" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <PackageReference Include="Mediatr" Version="9.0.0" />
+      <PackageReference Include="Mediatr.Extensions.Microsoft.DependencyInjection" Version="9.0.0" />
+    </ItemGroup>
+
 </Project>

src/backend/server/src/Todo.Infrastructure/DependencyInjection.cs

@@ -3,7 +3,8 @@ using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
-using Microsoft.IdentityModel.Protocols.OpenIdConnect;
+using Todo.Core.Application.Services.UserConnectionStore;
+using Todo.Infrastructure.UserConnectionStore;
 
 namespace Todo.Infrastructure;
 
@@ -20,6 +21,7 @@ public static class DependencyInjection
             .Bind(giteaOptions)
             .ValidateDataAnnotations();
 
+        services.AddSingleton<IUserConnectionStore, InMemoryUserConnectionStore>();
 
         return services.AddAuthentication(options =>
             {

src/backend/server/src/Todo.Infrastructure/Todo.Infrastructure.csproj

@@ -14,4 +14,8 @@
         <PackageReference Include="Microsoft.AspNetCore.Authentication.OpenIdConnect" Version="6.0.0" />
     </ItemGroup>
     
+    <ItemGroup>
+      <ProjectReference Include="..\Todo.Core\Todo.Core.csproj" />
+    </ItemGroup>
+
 </Project>

src/backend/server/src/Todo.Infrastructure/UserConnectionStore/InMemoryUserConnectionStore.cs

@@ -0,0 +1,50 @@
+using System.Collections.Concurrent;
+using Todo.Core.Application.Services.UserConnectionStore;
+
+namespace Todo.Infrastructure.UserConnectionStore;
+
+class InMemoryUserConnectionStore : IUserConnectionStore
+{
+    private static readonly ConcurrentDictionary<string, List<string>> ConnectedUsers = new();
+
+    public Task AddAsync(string userId, string connectionId)
+    {
+        // Try to get a List of existing user connections from the cache
+        ConnectedUsers.TryGetValue(userId, out var existingUserConnectionIds);
+
+        // happens on the very first connection from the user
+        existingUserConnectionIds ??= new List<string>();
+
+        // First add to a List of existing user connections (i.e. multiple web browser tabs)
+        existingUserConnectionIds.Add(connectionId);
+
+        // Add to the global dictionary of connected users
+        ConnectedUsers.TryAdd(userId, existingUserConnectionIds);
+
+        return Task.CompletedTask;
+    }
+
+    public Task<IEnumerable<string>> GetConnectionsAsync(string userId)
+    {
+        ConnectedUsers.TryGetValue(userId, out var connections);
+        return Task.FromResult(connections is null ? new List<string>().AsEnumerable() : connections.AsEnumerable());
+    }
+
+    public Task RemoveAsync(string userId, string connectionId)
+    {
+        ConnectedUsers.TryGetValue(userId, out var existingUserConnectionIds);
+
+        // remove the connection id from the List 
+        existingUserConnectionIds?.Remove(connectionId);
+
+        // If there are no connection ids in the List, delete the user from the global cache (ConnectedUsers).
+        if (existingUserConnectionIds?.Count == 0)
+        {
+            // if there are no connections for the user,
+            // just delete the userName key from the ConnectedUsers concurent dictionary
+            ConnectedUsers.TryRemove(userId, out _);
+        }
+
+        return Task.CompletedTask;
+    }
+}

src/backend/server/src/Todo.Persistence/Mongo/Repositories/Dtos/MongoTodo.cs

@@ -12,4 +12,5 @@ public record MongoTodo
     [BsonRequired] public string Title { get; init; }
     [BsonRequired] public bool Status { get; set; }
     public string ProjectName { get; set; } = String.Empty;
+    public string AuthorId { get; set; }
 }

src/backend/server/src/Todo.Persistence/Mongo/Repositories/TodoRepository.cs

@@ -15,9 +15,9 @@ public class TodoRepository : ITodoRepository
         _todosCollection = database.GetCollection<MongoTodo>("todos");
     }
 
-    public async Task<Core.Entities.Todo> CreateTodoAsync(string title, string projectName)
+    public async Task<Core.Entities.Todo> CreateTodoAsync(string title, string projectName, string userId)
     {
-        var todo = new MongoTodo() { Title = title, ProjectName = projectName };
+        var todo = new MongoTodo() { Title = title, ProjectName = projectName, AuthorId = userId };
         await _todosCollection.InsertOneAsync(todo);
         return new Core.Entities.Todo()
             { Id = todo.Id, Title = todo.Title, Status = false, Project = todo.ProjectName };
@@ -32,10 +32,10 @@ public class TodoRepository : ITodoRepository
                 new Core.Entities.Todo() { Id = t.Id, Title = t.Title, Status = t.Status, Project = t.ProjectName });
     }
 
-    public async Task UpdateTodoStatus(string todoId, bool todoStatus)
+    public async Task UpdateTodoStatus(string todoId, bool todoStatus, string userId)
     {
         await _todosCollection
-            .UpdateOneAsync(t => t.Id == todoId,
+            .UpdateOneAsync(t => t.Id == todoId && t.AuthorId == userId,
                 Builders<MongoTodo>.Update.Set(t => t.Status, todoStatus));
     }
 

src/client/src/components/todos/todoCheckmark.tsx

@@ -11,7 +11,7 @@ export const TodoCheckmark: FC<TodoCheckmarkProps> = (props) => (
     onClick={() =>
       props.updateTodo({ ...props.todo, status: !props.todo.status })
     }
-    className={`todo-checkmark h-5 w-5 rounded-full border dark:border-gray-500  ${
+    className={`todo-checkmark h-5 w-5 rounded-full border dark:border-gray-500 cursor-pointer  ${
       props.todo.status === StatusState.done
         ? "bg-gray-300 dark:bg-gray-500"
         : "hover:bg-gray-200 hover:dark:bg-gray-600"