Components are never or rarely associated with a site.
Normally, include the component in the site's global file (eg: require 'components/datetime.php';). You could just throw all the JS and CSS arrays in the component file you're requiring.
If you want, PHP, CSS and JS; you could probably have a global file (asset) which invokes the component. You would have to do some SQL with the asset_x_comp table. Make a function for this in case want to use again.