-- Магазин: списки и покупки.

CREATE OR REPLACE FUNCTION bot.get_titles_list()
    RETURNS TABLE(i integer, n character varying, p bigint)
    LANGUAGE plpgsql
AS $$
BEGIN
    RETURN QUERY
        SELECT id_title, title, price
        FROM bot.titles
        WHERE visible = true
        ORDER BY price DESC;
END;
$$;

CREATE OR REPLACE FUNCTION bot.get_donats_list()
    RETURNS TABLE(i integer, n character varying, p bigint)
    LANGUAGE plpgsql
AS $$
BEGIN
    RETURN QUERY
        SELECT id_donat, title, price
        FROM bot.donats
        WHERE visible = true
        ORDER BY price DESC;
END;
$$;

CREATE OR REPLACE FUNCTION bot.buy_title(p_id_user bigint, p_id_title integer)
    RETURNS integer
    LANGUAGE plpgsql
AS $$
DECLARE
    v_money bigint;
    v_price bigint;
BEGIN
    SELECT sum(amount) INTO v_money FROM bot.money WHERE id_user = p_id_user;
    SELECT price INTO v_price FROM bot.titles WHERE id_title = p_id_title;

    IF v_money IS NULL OR v_money < v_price THEN
        RETURN -1;
    END IF;

    CALL bot.money_action(p_id_user, -1 * v_price, 2);
    UPDATE bot.de_users SET id_title = p_id_title WHERE id_user = p_id_user;
    RETURN 1;
END;
$$;

CREATE OR REPLACE FUNCTION bot.buy_donat(p_id_user bigint, p_id_donat integer)
    RETURNS character varying
    LANGUAGE plpgsql
AS $$
DECLARE
    v_money bigint;
    v_price bigint;
    v_promo varchar;
BEGIN
    SELECT sum(amount) INTO v_money FROM bot.money WHERE id_user = p_id_user;
    SELECT price INTO v_price FROM bot.donats WHERE id_donat = p_id_donat;

    IF v_money IS NULL OR v_money < v_price THEN
        RETURN '-1';
    END IF;

    CALL bot.money_action(p_id_user, -1 * v_price, 2);
    v_promo := md5(random()::text);

    INSERT INTO bot.user_donats (id_user, id_donat, promo, stat)
    VALUES (p_id_user, p_id_donat, v_promo, false);

    RETURN v_promo;
END;
$$;