+ sufficient_perms = case action
+ when :manage
+ ['can_manage']
+ when :write
+ ['can_manage', 'can_write']
+ when :read
+ ['can_manage', 'can_write', 'can_read']
+ else
+ # (Skip this kind of permission opportunity
+ # if action is an unknown permission type)
+ end
+ if sufficient_perms
+ # Check permission links with head_uuid pointing directly at
+ # the target object. If target is a Group, this is redundant
+ # and will fail except [a] if permission caching is broken or
+ # [b] during a race condition, where a permission link has
+ # *just* been added.
+ if Link.where(link_class: 'permission',
+ name: sufficient_perms,
+ tail_uuid: groups_i_can(action) + [self.uuid],
+ head_uuid: target_uuid).any?
+ next
+ end
+ end