CREATE INDEX ix_products_performance1 ON products (
    parent_product_id
);

CREATE INDEX ix_products_performance2 ON products (
    CASE WHEN parent_product_id IS NULL THEN id ELSE parent_product_id END,
    active
);

CREATE INDEX ix_stock_performance1 ON stock (
    product_id,
    open,
    best_before_date,
    amount
);

DROP VIEW products_resolved;
CREATE VIEW products_resolved
AS
SELECT
    CASE
        WHEN p.parent_product_id IS NULL THEN
            p.id
        ELSE
            p.parent_product_id
    END AS parent_product_id,
    p.id as sub_product_id
FROM products p
WHERE p.active = 1;

DROP VIEW stock_missing_products_including_opened;
CREATE VIEW stock_missing_products_including_opened
AS

/* This is basically the same view as stock_missing_products, but the column "amount_missing" includes opened amounts */

-- Products WITHOUT sub products where the amount of the sub products SHOULD NOT be cumulated
SELECT
	p.id,
	MAX(p.name) AS name,
	p.min_stock_amount - (IFNULL(SUM(s.amount), 0) - IFNULL(SUM(s.amount_opened), 0)) AS amount_missing,
	CASE WHEN IFNULL(SUM(s.amount), 0) > 0 THEN 1 ELSE 0 END AS is_partly_in_stock
FROM products_view p
LEFT JOIN stock_current s
	ON p.id = s.product_id
WHERE p.min_stock_amount != 0
	AND p.cumulate_min_stock_amount_of_sub_products = 0
	AND p.has_sub_products = 0
	AND p.parent_product_id IS NULL
GROUP BY p.id
HAVING IFNULL(SUM(s.amount), 0) - IFNULL(SUM(s.amount_opened), 0) < p.min_stock_amount

UNION

-- Parent products WITH sub products where the amount of the sub products SHOULD be cumulated
SELECT
	p.id,
	MAX(p.name) AS name,
	SUM(sub_p.min_stock_amount) - (IFNULL(SUM(s.amount_aggregated), 0) - IFNULL(SUM(s.amount_opened_aggregated), 0)) AS amount_missing,
	CASE WHEN IFNULL(SUM(s.amount), 0) > 0 THEN 1 ELSE 0 END AS is_partly_in_stock
FROM products_view p
JOIN products_resolved pr
	ON p.id = pr.parent_product_id
JOIN products sub_p
	ON pr.sub_product_id = sub_p.id
LEFT JOIN stock_current s
	ON pr.sub_product_id = s.product_id
WHERE sub_p.min_stock_amount != 0
	AND p.cumulate_min_stock_amount_of_sub_products = 1
GROUP BY p.id
HAVING IFNULL(SUM(s.amount_aggregated), 0) - IFNULL(SUM(s.amount_opened_aggregated), 0) < SUM(sub_p.min_stock_amount)

UNION

-- Sub products where the amount SHOULD NOT be cumulated into the parent product
SELECT
	sub_p.id,
	MAX(sub_p.name) AS name,
	SUM(sub_p.min_stock_amount) - (IFNULL(SUM(s.amount), 0) - IFNULL(SUM(s.amount_opened), 0)) AS amount_missing,
	CASE WHEN IFNULL(SUM(s.amount), 0) > 0 THEN 1 ELSE 0 END AS is_partly_in_stock
FROM products p
JOIN products_resolved pr
	ON p.id = pr.parent_product_id
JOIN products sub_p
	ON pr.sub_product_id = sub_p.id
LEFT JOIN stock_current s
	ON pr.sub_product_id = s.product_id
WHERE sub_p.min_stock_amount != 0
	AND p.cumulate_min_stock_amount_of_sub_products = 0
GROUP BY sub_p.id
HAVING IFNULL(SUM(s.amount), 0) - IFNULL(SUM(s.amount_opened), 0) < sub_p.min_stock_amount;