-- Deploy numerus:invoice_amount to pg
-- requires: schema_numerus
-- requires: invoice_product
-- requires: invoice_tax_amount

begin;

set search_path to numerus, public;

create or replace view invoice_amount as
with taxable as (
	select invoice_id
	     , sum(round(price * quantity * (1 - discount_rate))::integer)::integer as subtotal
	from invoice_product
	group by invoice_id
), taxes as (
	select invoice_id
	     , sum(amount)::integer as tax_amount 
	from invoice_tax_amount
	group by invoice_id
)
select invoice_id
     , subtotal
     , subtotal + coalesce(tax_amount, 0) as total
from taxable
left join taxes using (invoice_id)
;

grant select on table invoice_amount to invoicer;
grant select on table invoice_amount to admin;

commit;