Would it be reasonably easy to adapt this Vera script to HA?

It seems like it wouldn’t be too hard, but my coding ability is pretty novice so I can’t really tell just by looking at it.

You mean something like ? : -

the environmental trigger is not really what I am asking about in this case.

It’s more the detailed manner in which the light brightness is controlled via scripting

Okay, I can’t help you then because I’m not familiar with vera, investigating your link is not germaine to HA and would therefore be of little use to me.
But given that you think “it wouldn’t be too hard” then when you’ve gained enough experience in HA / AppDaemon / NodeRed then you can sort it out and educate the rest of us.
Simulating light levels is a bit ambiguous as “Ideally” you’d need to acertain maximum sun elevation and declination and operate brightness on a sinusoid between those two points. I’m just not sure that’s a usable light (getting those two points is also difficult as the sun’s procession through the year changes these values, and the sun component evaluates elevation live. Perhaps Phil’s Sun2 component could make those available in advance, I don’t know, I don’t use it).
You could take an arbitrary maximum and minimum but again by what algorythm to apply it and again whether that would be a usefull light.
Good Luck

Everything you’ve written here is not related

Then why the hell report my post?

I was replying to the other guy @nickrout . misclicked on your post

The circadian component looks interesting, thanks

Sorry, I misunderstood your requirement