Redirect images to parent post but not Googlebot & Hotlink Protection

Hello !!

On my blog, I’ve more than 2000 images indexed on Google and no more than 1000 posts. Images has (normally) 1st position on Image Search Results.

I want to to this:
– Redirect user to the parent post when clic to access directly the image (www.mysite.com/2014/01/02/my-image.jpg). Parent post is the 1st post where the image is attached.
– Don’t redirect Googlebot. Google bot can continue indexing directly my images.
– Don’t redirect when I attach the image on my post.
– Prevent others to embed my images on their sites.

I think that it could be possible with a combination of htaccess rules and WordPress code on functions.php but I need some help.

Can anyone help me, pleas?

Thanks! ??