struct AuthenticationBackend {
  virtual User Authenticate(const std::string& user, const std:string& pass) = 0;
}

struct MySQLAuthenticationBackend {
  virtual User* Authenticate(const std::string& userName, const std:string& pass)
  {
    Result result = externalDBConnection->Query("SELECT user, pass FROM accounts WHERE user=? AND pass=HASH(?)", userName, pass);
    if (result->Size() == 1)
    {
      if (psEngine->HasUser(userName))
      {
         return psEngine->GetUser(userName);
      }
      else
      {
         return psEngine->CreateUser(userName, pass);
      }

    }
    return 0;
  }
}