Question AI that creates levels

Hi, so I've been working on a small grid-based leveled game. but I rather make code than actually make the levels so my question is: is it possible to make an AI that makes level for you and give it a difficulty range (1-10)
a level that I made has "level code" that looks likes this: aaaaaaaaaaaaaaaaaaaaaaaaaaaabaaaaaaabaaaaaaabaaaaaaabaaabbbbbaaabaaaaaaabaaaaaaa
a means there has to be a cube on that position.
b means there has to be air on that position.
so this code will create a level like this:

if anyone could link me a tutorial or guide on how to make an AI that creates levels like this. That would be great!

Thanks!

 

One great piece of advice from a GDC video (

) is basically this:

Make a really good level. Ask yourself what you did to make the level good. Make your level generator do that.

The same would go for difficulty. Make the easiest level. Make the hardest level. What did you do to make the level harder?