Attachment – Modifying Permalink Rewrites

Attachment – Modifying Permalink Rewrites

Good day! I cannot find any documentation regarding this matter. I would like to modify my attachment permalink. Instead of pointing to domain.com/post_slug/attachment_slug/ to domain.com/attachment/attachment_slug/. Is this possible?

/* add new rewrite rule */
function attachment_rewrite( $wp_rewrite ) {
    $rule = array(
        'media/(.+)' => 'index.php?attachment=' . $wp_rewrite->preg_index(1)
    );

    $wp_rewrite->rules = $rule + $wp_rewrite->rules;
}
add_filter( 'generate_rewrite_rules', 'attachment_rewrite' );

/* redirect standard wordpress attachments urls to new format */
function redirect_old_attachment() {
    global $wp;

    if( !preg_match( '/^media\/(.*)/', $wp->request ) && isset( $wp->query_vars['attachment'] ) ) {
        wp_redirect( site_url( '/media/' . $wp->query_vars['attachment'] ) , 301 );
    }
}
add_filter( 'template_redirect', 'redirect_old_attachment' );

I already have this but the problem is. There are two ways to visit an attachment page.

Like for example:
domain.com/this-is-a-post/this-is-an-attachment/ – When you visit this link you will be redirected to the link below. I want this to be disabled and I want it to point to this link rather domain.com/media/this-is-an-attachment/.

I read this is possible in the hook of attachment_link but I don’t have any idea. To be honest, my knowledge for permalink rewrites is limited. I really need your help guys.

Thanks and God Bless!