How to allow direct user input links the Facebook way?
You are looking for oembed, there is a Drupal module for it as well, that offers integration to media and some other modules.


  This module will allow your Drupal site to embed content from
  oEmbed-providers as well as for the site to become an oEmbed-provider
  itself so that other oEmbed-enabled websites can easily embed your
  content.


This won't give you a facebook experience out of the box, you still have to configure quiet a lot, you might want to read up on this: #2108973 Making oEmbed module work with WYSIWYG and CKeditor, which also links #2269433: Support URLs on a line by themselves in ckeditor/WYSIWYG.