--
-- 0024-find-rates-fix.sql
--
-- #23 - fix stored functions find_buy_rate and find_sell_rate
--
-- ISC License
--
-- Copyright 2023-2025 Brmlab, z.s.
-- TMA <tma+hs@jikos.cz>
--
-- Permission to use, copy, modify, and/or distribute this software
-- for any purpose with or without fee is hereby granted, provided
-- that the above copyright notice and this permission notice appear
-- in all copies.
--
-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
-- WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
-- WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
-- AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
-- CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
-- OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
-- NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
-- CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
--

-- To require fully-qualified names
SELECT pg_catalog.set_config('search_path', '', false);

DO $upgrade_block$
BEGIN

IF brmbar_privileged.has_exact_schema_version(23) THEN

DROP FUNCTION IF EXISTS public.find_buy_rate(integer,integer);
DROP FUNCTION IF EXISTS public.find_sell_rate(integer,integer);

CREATE OR REPLACE FUNCTION public.find_buy_rate(
	IN i_item_currency_id public.accounts.id%TYPE,
	IN i_other_currency_id public.accounts.id%TYPE
) RETURNS NUMERIC
LANGUAGE plpgsql
AS $$
DECLARE
	v_rate public.exchange_rates.rate%TYPE;
	v_rate_dir public.exchange_rates.rate_dir%TYPE;
BEGIN
        SELECT rate, rate_dir INTO STRICT v_rate, v_rate_dir FROM public.exchange_rates WHERE target = i_item_currency_id AND source = i_other_currency_id AND valid_since <= NOW() ORDER BY valid_since DESC LIMIT 1;
	IF v_rate_dir = 'target_to_source'::public.exchange_rate_direction THEN
		RETURN v_rate;
	ELSE
		RETURN 1/v_rate;
	END IF;
	/* propagate error
EXCEPTION
	WHEN NO_DATA_FOUND THEN
		RETURN -1;
	*/
END;
$$;

-- return negative number on rate not found
CREATE OR REPLACE FUNCTION public.find_sell_rate(
	IN i_item_currency_id public.accounts.id%TYPE,
	IN i_other_currency_id public.accounts.id%TYPE
) RETURNS NUMERIC
LANGUAGE plpgsql
AS $$
DECLARE
	v_rate public.exchange_rates.rate%TYPE;
	v_rate_dir public.exchange_rates.rate_dir%TYPE;
BEGIN
        SELECT rate, rate_dir INTO STRICT v_rate, v_rate_dir FROM public.exchange_rates WHERE target = i_other_currency_id AND source = i_item_currency_id AND valid_since <= NOW() ORDER BY valid_since DESC LIMIT 1;
	IF v_rate_dir = 'source_to_target'::public.exchange_rate_direction THEN
		RETURN v_rate;
	ELSE
		RETURN 1/v_rate;
	END IF;
	/* propagate error
EXCEPTION
	WHEN NO_DATA_FOUND THEN
		RETURN -1;
	*/
END;
$$;

PERFORM brmbar_privileged.upgrade_schema_version_to(24);
END IF;

END;
$upgrade_block$;

-- vim: set ft=plsql :