How do i know the current post type when on post.php in admin?

add_action( 'admin_init', 'do_something_152677' );
function do_something_152677 () {
    // Global object containing current admin page
    global $pagenow;

    // If current page is post.php and post isset than query for its post type 
    // if the post type is 'event' do something
    if ( 'post.php' === $pagenow && isset($_GET['post']) && 'post' === get_post_type( $_GET['post'] ) )
        // Do something
    }
}