IF and AND Function with 3 possibilities

Hi, please help

I need an excel formula for one cell that combines the following for a cell A3 (official working hours). This is to create a template for calculating working hours and overtime based on the type of day, with cell A1 stating the type of day and A2 listing their Time-In
(WD=work day, or REST day or PH=Public Holiday or include MC=Medical Leave, UPL=Unpaid Leave, AL=Annual Leave, CCL=Childcare Leave, OL=Other Leaves)


IF A2 is blank, then cell A3 would be blank
- This is if they are on leaves or "REST" or "PH" and do not come back for work, therefore I do not want the cell to be filled at all

IF A1=not "WD" AND A2 is not blank, then cell A3 would be "0"
- This would count for days they are on "REST" or "PH" but come back to work, therefore official working hours cell A3 is "0"

IF A1="WD" and A2 is not blank, then cell A3 would be "8"
- This is for official working days and with Time-in filled