public function __construct(\OrderItem $item)
{
$this->item = $item;
$this->quantity = $item->Quantity;
$originalprice = method_exists($item, "DiscountableAmount") ? $item->DiscountableAmount() : $item->UnitPrice();
parent::__construct($originalprice);
}
/**
* Work out the discount for a given order.
*
* @param Order $order
* @return double - discount amount
*/
public function calculate()
{
$total = 0;
// clear any existing linked discounts
$this->modifier->Discounts()->removeAll();
// work out all item-level discounts, and load into infoitems
$infoitems = $this->createPriceInfoList($this->order->Items());
foreach ($this->getItemDiscounts() as $discount) {
// item discounts will update info items
$action = $discount->Type === "Percent" ? new \ItemPercentDiscount($infoitems, $discount) : new \ItemFixedDiscount($infoitems, $discount);
$action->perform();
}
// select best item-level discounts
foreach ($infoitems as $infoitem) {
$bestadjustment = $infoitem->getBestAdjustment();
if (!$bestadjustment) {
continue;
}
$amount = $bestadjustment->getValue();
// prevent discounting more than original price
if ($amount > $infoitem->getOriginalTotal()) {
$amount = $infoitem->getOriginalTotal();
}
$total += $amount;
// remove any existing linked discounts
$infoitem->getItem()->Discounts()->removeAll();
$infoitem->getItem()->Discounts()->add($bestadjustment->getAdjuster(), array('DiscountAmount' => $amount));
$this->logDiscountAmount("Item", $amount, $bestadjustment->getAdjuster());
}
// work out all cart-level discounts, and load into cartpriceinfo
$cartpriceinfo = new PriceInfo($this->order->SubTotal());
foreach ($this->getCartDiscounts() as $discount) {
$action = new \SubtotalDiscountAction($this->getDiscountableAmount($discount), $discount);
$action->reduceRemaining($this->discountSubtotal($discount));
$adjust = new Adjustment($action->perform(), $discount);
$cartpriceinfo->adjustPrice($adjust);
}
$cartremainder = $cartpriceinfo->getOriginalPrice() - $total;
// keep remainder sane, i.e above 0
$cartremainder = $cartremainder < 0 ? 0 : $cartremainder;
// select best cart-level discount
if ($bestadjustment = $cartpriceinfo->getBestAdjustment()) {
$discount = $bestadjustment->getAdjuster();
$amount = $bestadjustment->getValue();
// don't let amount be greater than remainder
$amount = $amount > $cartremainder ? $cartremainder : $amount;
$total += $amount;
$this->modifier->Discounts()->add($discount, array('DiscountAmount' => $amount));
$this->logDiscountAmount("Cart", $amount, $discount);
}
if (class_exists('ShippingFrameworkModifier') && ($shipping = $this->order->getModifier("ShippingFrameworkModifier"))) {
// work out all shipping-level discounts, and load into shippingpriceinfo
$shippingpriceinfo = new PriceInfo($shipping->Amount);
foreach ($this->getShippingDiscounts() as $discount) {
$action = new \SubtotalDiscountAction($shipping->Amount, $discount);
$action->reduceRemaining($this->discountSubtotal($discount));
$shippingpriceinfo->adjustPrice(new Adjustment($action->perform(), $discount));
}
//select best shipping-level disount
if ($bestadjustment = $shippingpriceinfo->getBestAdjustment()) {
$discount = $bestadjustment->getAdjuster();
$amount = $bestadjustment->getValue();
//don't let amount be greater than remainder
$total += $amount;
$this->modifier->Discounts()->add($discount, array('DiscountAmount' => $amount));
$this->logDiscountAmount("Shipping", $amount, $discount);
}
}
return $total;
}