Requested WoW macro

I'm looking for a macro that will allow me to toggle forms back into caster if a travel form is already selected. So essentially:

Use aquatic if swimming,
Otherwise use flight form if not in combat and flyable,
Otherwise use travel form if in combat or not flyable,
Otherwise use cat form if indoors,
go back to caster form (drop all auras) if any of these auras are already in effect, even if in flight.

Thanks.