<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def generate_username_and_redirect(self, request, user, profile, client):
 """ Generate a username and then redirect the user to the correct place. This method is called when ``SOCIALREGISTRATION_GENERATE_USERNAME`` is set. :param request: The current request object :param user: The unsaved user object :param profile: The unsaved profile object :param client: The API client """

        func = self.get_username_function()
        
        user.username = func(user, profile, client)
        user.set_unusable_password()
        user.save()
        
        profile.user = user
        profile.save()
        
        user = profile.authenticate()
        
        self.send_connect_signal(request, user, profile, client)
        
        self.login(request, user)
        
        self.send_login_signal(request, user, profile, client)
        
        self.delete_session_data(request)
        
        return HttpResponseRedirect(self.get_next(request))