Pool System

The plugin includes an automatic protection system against applying multiple discounts to the same item. This system is called the Cart Pool.

How It Works

Initialization — At the beginning, a “pool” of all cart items is created with no discounts applied
Processing by priority — Discounts are processed according to priority (lower number = processed first)
Pool consumption — After a discount is applied, the item is removed from the pool
Next discount validation — Subsequent discounts only see the remaining items

The pool system is primarily used for:

For BOGO discounts, trigger products are also removed from the pool.

Pool at start: 10 units of product A

Phase	Pool	Applied	Remaining
Start	10 units	—	—
Discount 1 (priority 0)	10 units	3 units trigger + 1 unit discount	6 units
Discount 2 (priority 10)	6 units	2 units trigger + 1 unit discount	3 units

Discount 1 (priority 0): Buy 3 Get 1

Discount 2 (priority 10): Buy 2 Get 1

Priority determines access to the full pool. Lower priority values are processed first and have access to the complete inventory.

With 5 units of product A:

Result: Rule A is applied to 3 units, 2 units remain. Rule B needs 3 units, so it is not applied.

Set better/higher discounts with a lower priority so they are applied first:

To visualize the pool state, use the debug panel.