[EP-underground] Integrating full text to eprints

Has anyone tried truly integrating full text search into the eprints software? By integration I mean a common search interface, with both metadata AND full text search at once. (All the full text search I found was two separate searches and of course the results list didn't use the metadata, but some excerpt from the text.)

One (apparently) easy way to do this would be to use an already existing search engine (like ht://dig), and pass the results (eprint ID is in the URL of the documents) to the eprints software, and combine the id search with the metadata search from the original search form. I know that some information would be lost (relevence ordering of the full text search, for example) but this seems to be a good start. Now this works in theory, but I have no idea how difficult it is to implement this. 

Any suggestions? Thanks, 

Tamas Dombos