parsing `git cat-file tag <tag-id>`

Hello, I need to parse output of `git cat-file tag <tag-id>` in bash
to get information from the (annotated) tag like author, email, date,
subject, body. Everyone has ever done something similar?

What would be the recommended tool in bash?

Originally, my problem is that I have tag-id and I would like to
directly from tag-id by calling a git command the individual fields
from the tag content. I don't want any <tag-id> to <tag-name>
translation first and i cannot use for-each-ref --points-at=<tag-id>
because it's not in older versions of git. Thank you very much!

clime