I've installed haskell-mode and some others from the package manager.

Yet I have no auto-completion, no go-to-definition, no overview, no function lookup/search.

I use Eclipse for Java, and it works out of the box.

The lack of an easy-to-setup IDE is something I really miss in "Haskell environment".

How much time would it take to setup emacs as an IDE for Haskell?

Considering I'm pretty newby as emacs.