I'm building a website to help a friend who schedules piano lessons. They use Google Calendar to track lessons, and I'm building a website for them to manage students, lesson packages, etc.
The customer-facing portion of the site can use a read-only embedded Google Calendar (which I already know how to find). I would like to embed the fully-functional Google Calendar to their admin pages, however, so they can manage their schedule through the same web interface, as could other people on their team who are logged in to the admin portion of their website.
Is there any way to do this without re-building Google Calendar from scratch using the APIs? (I keep considering doing that, with just the core "credit/edit/delete events" functionality, but I feel like I'm reinventing the wheel for no reason.)