Is there a good calendar (gem) for Rails for multiple users?

I would like to implement a calendar with authorizations in Rails. My application has two sort of users: administrators and customers. The specification of the calendar would be as follows:

• an administrator can add / delete / edit events
• events added by the administrators could be tagged either as visible to all (i.e. admins and customers) or to administrators only
• a customer can add / delete / edit their own events
• the events added by a customer can be seen by that customer (and not other customers) as well as all the administrators
• events added by customers can be edited and deleted by administrators (triggering an email to the customer)

I looked around but found mainly nice calendars with no authorization concept. Would you have any pointer, if not to a ready-made solution at least to something I could build upon ?

Any idea would be greatly appreciated :)

I ended up using fullcalendar with Vue for front-end and Rails for backend. The learning curve was... interesting, but I got what I needed and even more.