Is Automator suitable for complex folder based workflows? I have a rather puzzling scenario for you, one that I would like to solve with Automator:

We're a startup that creates HD music video content that is streamed online; we've got a custom-programmed Linux/Unix backend that takes HD videos from a folder, processes them for streaming, and throws them up in a Web format so that they can be viewed/streamed/downloaded from our site. Let us call that folder Folder D for the sake of this problem.

When a video editor has a completed project, he or she adds their project to Folder A, Folder B, or Folder C, each of which is a folder on a volume on our SAN. The SAN has 3 volumes, any of which can be mounted RW on one machine at a time, so at any time up to 3 people can be adding content to A, B or C.

What I'd like to do in Automator, if possible:


Watch folders A, B &amp; C for new videos.
When a video is dropped into one of those folders, copy it to Folder D.
Our backend system works on D and then deletes the file from D.
The tricky part is making sure that once the file is deleted from D, it isn't re-added from A, B or C.
Because of the SAN's limited RW access, assume that A, B and C cannot be written to from the machine where Folder D is located.


I am basically unsure of how to specify something like "once this video has shown up once in Folder D, ignore it if it ever shows up again" and don't know a way to do that without somehow accessing the originals on A, B &amp; C and renaming them
There is a similar workflow kit at http://forums.macrumors.com/showthread.php?t=805573 that takes disc images (dvd, bluray, etc.) and converts them to various formats.  There are a number of actions you could copy for file movement, etc., and attach them as folder actions to A, B, and C.

It should also be a simple matter to pick and choose which actions and workflows you would require for this.

Even better, the underlying technology for these actions are just shell scripts.  If you can write a shell, ruby, python, etc. script, you can create your own Automator action.  You could easily store state regarding files in A, B, and C that have already been copied to D and only copy them again if certain criteria are met, such as a change in file size, modify date, or md5 hash.