I’m trying to make a Social App like Facebook where you can add people as friends.
Now, I want to add a “People you may know section” in which all application users appears except your friends.
I Made a Model “ApplicationUser” that have a self Many-to-Many relationship so that a user can have multiple friends. Here’s the Definition of “ApplicationUser” Model :

public class ApplicationUser : IdentityUser
{
    public string Fullname { get; set; }

    public DateOnly BirthDate { get; set; }

    public string? ProfilePicUrl { get; set; }

    public string Bio {  get; set; }

    public ICollection<User_Friend> Users { get; set; }
    public ICollection<User_Friend> Friends { get; set; }
}

And here’s the Definition of “User_Friend” Model that maps the M-N relation :

public class User_Friend
{
    public int Id { get; set; }

    public string UserId { get; set; }

    public ApplicationUser User { get; set; }

    public string FriendId { get; set; }

    public ApplicationUser Friend { get; set; }

    public DateTime FriendsSince { get; set; }

}

here’s my code , it’s working as expected but it looks like there must be a better or cleaner way

public IActionResult Index()
{
    var claim = (ClaimsIdentity)User.Identity;
    var user = claim.FindFirst(ClaimTypes.NameIdentifier);

    //everyone ids except me
    List<string> AllIds  = _context.applicationUsers.Where(u => u.Id != user.Value).Select(x=>x.Id).ToList();
    // friends ids
    List<string> friendsIds = _context.user_Friends.Where(u => u.UserId == user.Value).Select(x=>x.FriendId).ToList();
    // non-friends ids
    List<string> nonFriendsIds = AllIds.Except(friendsIds).ToList();

    List<ApplicationUser> nonFriends = new List<ApplicationUser>();
    
    if (user != null)
    {
        foreach (var x in nonFriendsIds)
        {
            nonFriends.Add(_context.applicationUsers.FirstOrDefault(u => u.Id == x));
        }
    }

    return View(nonFriends);
}