Customize Jomsocial - Appointments Addon -- 2

Specification requirements I need a customization of an add-on to Jomsocial called jomsocialappointments. The problem is that: Appointments for JomSocial was created and designed as a "Personal Appointment" for users to be used with their friends only. The status of each calendar for each member is "Private". User must login to the system in order to see and use the appointment (if you don't login, you won't be able to use or see the system). And I need the users or guests to be able to see the calendar and the invitations that are “open”, and not closed. I need an online appointment calendar, which is already implemented on the profile login, but this calendar should be public and placed on the frontpage. Every new visitor should be able to look at the appointments, and "apply" for each appointment on the calendar. And all registered users should be able to make “open” invitations, that guests can apply to. The website is based on Joomla, and PHP. Thus, this customization should be made in php. Testing of your work: 1) Registered user should be able to make an “appointment”, which is in fact an invitation to other users to join. This registered user, should get an notification if a guest or another registered user wants to join his appointment. 2) The registered user should be able to refuse or accept the other registered user / or guest. The other registered user / or guest will receive notification of the refusal or acceptance. 3) The calendar is public. But the users should be able to make their appointment “non-public”. 4) This customization should be based on the module “Jomsocial Appointments” which is already installed. Please ask if you have any questions.