Macro conditionals are basically if/then/else, but you are limited to the conditionals that are allowed in macros. (So, things like if your target/mouseover/focus is friendly/alive and such.)
So, for example, here’s a Spirit Mend macro I use:
#showtooltip
/cast [@mouseover, help,nodead][@player] Spirit Mend
That breaks down to:
If whatever is under my mouse is friendly and alive
Then cast Spirit Mend on what my mouse is over
Else
Then cast Spirit Mend on me
There are no conditionals to tell if a spell is on cooldown (or to see if buff/debuffs are active) so nothing that will do what you’re looking for in your example. There’s a sticky at the top of this forum with more details on what can be done with macros.