How to set up salvo fire in unit lua file

Hi, I need some help if anyone knows how to do this.

I have a unit that can fire 4 missiles in quick succession then needs to reload then it can fire again, it has 12 missiles total, and after that it should not get more.

So the sequence I want to get to it is:

fire-2sec- fire-2sec-fire-2sec-fire-2sec-60sec

fire-2sec- fire-2sec-fire-2sec-fire-2sec-60sec

fire-2sec- fire-2sec-fire-2sec-fire-2sec-empty

I played around with the variables:

reactionTime

launch_delay

shot_delay

ammo_capacity

portionAmmoCapacity

reload_time

But I'm not entirely sure what I'm doing. Is there any kind of documentation about this somewhere?

Bonus:

Also I want to make this same system with 2 missile types, but on ammo change there need to be a 60 sec delay as well.