Query suggestion multi fields + raw field and with results new created boosted

we are trying to query 3 fields for a given text.
3 fields are
body, title and raw-body (not analyzed). title is of the most importance
and then the body and raw-body. if thing matches exactly with raw-body
we want it to be ranked higher. Also if matches are identical in 2
documents we want to use decay function for promotion of fresh content.

Can you please give me some idea how we can write this complicated query?

Thanks in advance.