roles and permissions

[kerolloz]

when a problem_setter wants to delete or update a problem, we must check if he is the same setter of the problem so a problem_setter can't delete or update a problem created by another problem_setter. but the question is what about the admin? should he be able to update or delete any problem whether he is the setter or not? this also leads to another question... if an admin creates a problem (or a contest) should any other admin be able to update or delete it!
@amrsalama please check this.

[kerolloz]

I suggest one of the 2 following approaches:

• an admin can update or delete any problem (or contest) whether it's made by another admin or a problem_setter.
• the setter(an admin or a problem setter) of the problem(or contest) is the only one allowed to update or delete it.

NOTICE: a problem_setter can only create problems. a problem_setter is NOT allowed to create contests -- creating contests is only allowed for admins.

so what do you think?