This has nothing to do with the noai option. What you are experiencing, is a little trouble copy-pasting a load of text _with existing indents_ to vim.
What I usually do (I have this 'problem' a lot), is bind F4 to invpaste and then, before I paste stuff into vim, hit that key. It makes the problem go away.
nnoremap
Read more about this using
:help paste
inside vim