//http://localhost:51473/token
        //grant_type=password&username=admin1&password=1234561
        //application/x-www-form-urlencoded
        public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context)
        {
            IdentityUser user = null;
            using (AuthRepository _repo = new AuthRepository())
            {
                var username = context.UserName;
                if (context.UserName.Contains("@"))
                {
                    var userForEmail = await _repo.FindByEmailAsync(context.UserName);
                    if (userForEmail != null)
                    {
                        username = userForEmail.UserName;
                    }
                }
                user = await _repo.FindUser(username, context.Password);

                if (user == null)
                {
                    context.SetError("invalid_grant", "The username or password is incorrect.");
                    return;
                }

                var identity = new ClaimsIdentity(context.Options.AuthenticationType);
                identity.AddClaim(new Claim("user_name", context.UserName));

                var roleCollection = string.Empty;
                foreach (var role in user.Roles)
                {
                    var userRole = _repo.FindRole(role.RoleId);
                    roleCollection = string.IsNullOrEmpty(roleCollection) ? userRole.Name  : roleCollection + '-' + userRole.Name;
                    identity.AddClaim(new Claim(ClaimTypes.Role, userRole.Name));
                }

                AuthenticationProperties properties = CreateProperties(user.UserName, roleCollection);
                AuthenticationTicket ticket = new AuthenticationTicket(identity, properties);

                context.Validated(ticket);
            }
        }
 public AccountController()
 {
     _repo = new AuthRepository();
 }