Add user avatar and profile feature, consolidate Auth and UserManagement features (#257)

web/backend/Features/Features.Users/Commands/Authentication/RegisterUser/RegisterUserHandler.cs

@@ -0,0 +1,90 @@
+using Domain.Entities;
+using Domain.Exceptions;
+using Features.Auth.Commands.Profile.CreateUserProfile;
+using Features.Auth.Dtos;
+using Features.Auth.Identity;
+using Features.Auth.Services;
+using MediatR;
+using Microsoft.AspNetCore.Identity;
+using Shared.Application.Emails;
+
+namespace Features.Auth.Commands.Authentication.RegisterUser;
+
+/// <summary>
+///     Handles <see cref="RegisterUserCommand" />: creates the user via <see cref="UserManager{TUser}" />
+///     (which validates uniqueness and hashes the password), issues access/refresh/confirmation tokens, and
+///     attempts to send the registration confirmation email via Features.Emails.
+/// </summary>
+public class RegisterUserHandler(
+    UserManager<ApplicationUser> userManager,
+    ITokenService tokenService,
+    IMediator mediator
+) : IRequestHandler<RegisterUserCommand, RegistrationPayload>
+{
+    /// <exception cref="ConflictException">
+    ///     Thrown when an existing account already has the same username or email address, or when user
+    ///     creation otherwise fails.
+    /// </exception>
+    public async Task<RegistrationPayload> Handle(
+        RegisterUserCommand request,
+        CancellationToken cancellationToken
+    )
+    {
+        ApplicationUser user = new UserAccount
+        {
+            Username = request.Username,
+            Email = request.Email,
+            FirstName = request.FirstName,
+            LastName = request.LastName,
+            DateOfBirth = request.DateOfBirth,
+        }.ToApplicationUser();
+
+        IdentityResult result = await userManager.CreateAsync(user, request.Password);
+        if (!result.Succeeded)
+        {
+            if (result.Errors.Any(e => e.Code is "DuplicateUserName" or "DuplicateEmail"))
+                throw new ConflictException("Username or email already exists");
+            throw new ConflictException(
+                string.Join("; ", result.Errors.Select(e => e.Description))
+            );
+        }
+
+        await mediator.Send(new CreateUserProfileCommand(user.Id, string.Empty), cancellationToken);
+
+        string accessToken = tokenService.GenerateAccessToken(user.Id, user.UserName);
+        string refreshToken = tokenService.GenerateRefreshToken(user.Id, user.UserName);
+        string confirmationToken = tokenService.GenerateConfirmationToken(user.Id, user.UserName);
+
+        if (string.IsNullOrEmpty(accessToken) || string.IsNullOrEmpty(refreshToken))
+            return new RegistrationPayload(
+                user.Id,
+                user.UserName,
+                string.Empty,
+                string.Empty,
+                false
+            );
+
+        bool emailSent = false;
+        try
+        {
+            await mediator.Send(
+                new SendRegistrationEmailCommand(user.FirstName, user.Email, confirmationToken),
+                cancellationToken
+            );
+            emailSent = true;
+        }
+        catch (Exception ex)
+        {
+            await Console.Error.WriteLineAsync(ex.Message);
+            Console.WriteLine("Could not send email.");
+        }
+
+        return new RegistrationPayload(
+            user.Id,
+            user.UserName,
+            refreshToken,
+            accessToken,
+            emailSent
+        );
+    }
+}