A very special mask

Hello everybody !

So i've a very specific request.

I need a mask that do these thing:

- the password is 8 chars uppercase (ok i know that: ?u?u?u?u?u?u?u?u).
- The passwork have max two time the same letter.
- if the password contain two time the same letter, they are never next to the other.
- the password nerver have the same 2 or more letter sequency (ABCDEFAB doesn't work because AB is repeted).

If someone here can do something like that (without hundreds lines of code) then this is a genius.

Thank you everybody.
R4ms3s.