❔ SignalR

 public async Task SetUserIdentifier(string userIdentifier)
        {
            try
            {
                Console.WriteLine($"Setting user identifier to {userIdentifier}");

                var user = await _dbContext.Users.FirstOrDefaultAsync(u => u.UserName == userIdentifier);

                if (user == null)
                {
                    user = new User { UserName = userIdentifier };
                    await _dbContext.Users.AddAsync(user);
                    await _dbContext.SaveChangesAsync();
                }                              

                await Groups.RemoveFromGroupAsync(Context.ConnectionId, user.Id);
                await Groups.AddToGroupAsync(Context.ConnectionId, user.Id);
                await Clients.Caller.SendAsync("UserIdentifierSet", user.Id);

            }
            catch (Exception ex)
            {
                Console.WriteLine($"Exception: {ex.Message}");
            }
        }

builder.Services.AddDbContext<ApplicationDBContext>(options =>
{
    options.UseInMemoryDatabase(databaseName: "MyDatabase");
});
builder.Services.AddIdentity<User, IdentityRole>()
    .AddEntityFrameworkStores<ApplicationDBContext>()
    .AddDefaultTokenProviders();
builder.Services.AddSingleton<IUserIdProvider, CustomUserIdProvider>();

 public string GetUserId(HubConnectionContext connection)
    {
        // Get the authenticated user's ID from the ClaimsPrincipal
        var userIdClaim = connection.User?.FindFirst(ClaimTypes.NameIdentifier);

        if (userIdClaim != null)
        {
            return userIdClaim.Value;
        }

        // If the user is not authenticated or the NameIdentifier claim is not present, return null
        return null;
    }

  public async Task SetUserIdentifier(string userIdentifier)
        {
            try
            {
                Console.WriteLine($"Setting user identifier to {userIdentifier}");

                var user = await _dbContext.Users.FirstOrDefaultAsync(u => u.UserName == userIdentifier);

                if (user == null)
                {
                    user = new User { UserName = userIdentifier };
                    await _dbContext.Users.AddAsync(user);
                    await _dbContext.SaveChangesAsync();
                }

                var claims = new List<Claim>
        {
            new Claim(ClaimTypes.Name, user.UserName)
        };
                var userIdentity = new ClaimsIdentity(claims, "login");
                var userPrincipal = new ClaimsPrincipal(userIdentity);


                await Groups.RemoveFromGroupAsync(Context.ConnectionId, user.Id);
                await Groups.AddToGroupAsync(Context.ConnectionId, user.Id);
                await Clients.Caller.SendAsync("UserIdentifierSet", user.Id);

            }
            catch (Exception ex)
            {
                Console.WriteLine($"Exception: {ex.Message}");
            }
        }