/**
* Gets the total discount from $order
* inkl. and excl. tax
* Data is returned as a Varien_Object with these data-keys set:
* - discount_incl_tax
* - discount_excl_tax
*
* @param Mage_Sales_Model_Order $order
*
* @return Varien_Object
*/
public function getOrderDiscountData(Mage_Sales_Model_Order $order)
{
// if catalog-prices includes tax
$CatPriceIncl = Mage::getStoreConfig(Mage_Tax_Model_Config::CONFIG_XML_PATH_PRICE_INCLUDES_TAX, $order->getStore());
$discountIncl = 0;
$discountExcl = 0;
// find discount on the items
foreach ($order->getItemsCollection() as $item) {
/** @var Mage_Sales_Model_Quote_Item $item */
if (!$CatPriceIncl) {
$discountExcl += $item->getDiscountAmount();
$discountIncl += $item->getDiscountAmount() * ($item->getTaxPercent() / 100 + 1);
} else {
$discountExcl += $item->getDiscountAmount() / ($item->getTaxPercent() / 100 + 1);
$discountIncl += $item->getDiscountAmount();
}
}
// find out tax-rate for the shipping
if ((double) $order->getShippingInclTax() && (double) $order->getShippingAmount()) {
$shippingTaxRate = $order->getShippingInclTax() / $order->getShippingAmount();
} else {
$shippingTaxRate = 1;
}
// get discount amount for shipping
$shippingDiscount = (double) $order->getShippingDiscountAmount();
// apply/remove tax to shipping-discount
if (!$CatPriceIncl) {
$discountIncl += $shippingDiscount * $shippingTaxRate;
$discountExcl += $shippingDiscount;
} else {
$discountIncl += $shippingDiscount;
$discountExcl += $shippingDiscount / $shippingTaxRate;
}
$return = new Varien_Object();
return $return->setDiscountInclTax($discountIncl)->setDiscountExclTax($discountExcl);
}
