multiple conflict targets

if I read https://www.postgresql.org/docs/9.6/static/sql-insert.html correctly there can be only one conflict target or none at all.

What if I have a table with 3 unique constraints? If the first one is violated by the insert I want to do nothing. If the 2nd is violated some fields should be updated. And violation of the 3rd one should raise an error.

Can that be expressed?

Thanks,

Torsten