Postgres, "JOIN table if execute condition" in single query

postgres_join_if_condition.sql

set session my.vars.user_id = 0; -- not entered
set session my.vars.user_id = 1;-- entered, user.id=1

select
	*
from 
	services sv
	
-- favorite, (join only if user.id > 0)
LEFT JOIN
	suser_customuser_favorite_services suf	
ON 		(sv.service_id = suf.service_id AND    (    	
-- не авторизирован    	
(current_setting('my.vars.user_id')::int = 0 and suf.id=0)    OR    	

-- авторизирован    	
(current_setting('my.vars.user_id')::int > 0 and suf.customuser_id = current_setting('my.vars.user_id')::int)    ))