Semi automated migration tool to Drupal from arbitration HTML

I've got a few old websites built with static HTML files and want to migrate them all to Drupal. All sites are multilingual (meaning, I need to the import tool to support that too).

My idea is to write a script that would spider the existing site, build the corresponding Drupal page for each static file and patch all internal links and embedded objects.
I'll have to add some markers to each page (HTML comments) that would tell the script what part of the page to copy (so that I don't include menus and repeating stuff in each page). These markers would also include the language information.

To run it, the script will log into Drupal and remotely create the new contents. I recon that some manual fixup work would still be required, but all the HTML, images and other stuff will be there.

1. Is there anything out there that can do this?
2. If you would be writing such tool, how would you go about it?
3. Do you think it's a good idea to write as a Drupal module and not an offline script?