from rest_framework.permissions import BasePermission, SAFE_METHODS


class IsActiveUser(BasePermission):

    def has_permission(self, request, view):
        return request.user and request.user.is_active 


class IsSuperAdmin(BasePermission):
    """
    Allows access to super admins and admins with full panel privileges.
    """
    def has_permission(self, request, view):
        return (
            request.user and
            request.user.is_authenticated and
            (request.user.is_super_admin_panel_user() or request.user.is_admin_panel_user())
        )


class IsPanelUser(BasePermission):
    """
    Allows access to super admins, admins, and professors.
    """
    def has_permission(self, request, view):
        return (
            request.user and
            request.user.is_authenticated and
            request.user.can_access_admin_panel()
        )


class IsSuperAdminOrReadOnlyForProfessor(BasePermission):
    """
    Allows full read-write access to super admins and admins,
    but only read-only (GET, HEAD, OPTIONS) access to professors.
    """
    def has_permission(self, request, view):
        if not request.user or not request.user.is_authenticated or not request.user.is_active:
            return False
        
        # Super admin / admin can do everything
        if request.user.is_super_admin_panel_user() or request.user.is_admin_panel_user():
            return True
            
        # Professor has read-only access
        if request.user.is_professor_panel_user():
            return request.method in SAFE_METHODS
            
        return False