Online Booking Clinics/Presets/Appt Types

I want to restrict the types of appointments that can be booked online eg; when our books are open on a Sunday, I want patients to ONLY be able to book a "Sunday Emergency" appt with a specific booking fee.
This would also extend to New Patient appointments eg; rather than booking out our whole day with low value New Patient appointments, I want to reserve mornings for high-value treatments like Crowns/Implants & only allow New Patient appointments to be booked online into Calendar "events/presets/clinics" that I have made available for a specific appointment type.
This is a feature that is readily available in all of your competitors practice management software ie Exact.
How quickly could this code be written & implemented please?