How do I set up AI?

So guys, I have looked up but can't seem to find it. How exactly do I make a enemy, which patrols back and forth. Then, when i come within an area it turns and (it stands still) shoots at me. I couldn't seem to figure it out myself. Thanks in advance.

Here you find a capx with different AI types (including on sight)

https://www.scirra.com/tutorials/1270/b ... latformers

the code is a little bit messy, but you can figure out the basic AI stuff.

Thanks a lot! never saw this in my search!

You might want to try line of sight behavior as well as using alot of invisible sprite helper.