getting all roles who specific user {id} don't have

here is table structure i know ec_users and user_id is wrong but i don't have permission to change -

ec_users
- user_id
- name
- email

roles
- id
- name

model_has_roles
- role_id
- model_type
- model_id

i know is something like that but i don't know how to add relationship

$userId = 1;  

$roles = Role::whereDoesntHave('users', function ($query) use ($userId) {
    $query->where('users.id', $userId);
})->get();