Hjdcti

I am adding custom discount to my cart but it seems it is adding 2 times in the cart.

Here is my model file code.

$discount = 10;
$baseDiscount = 10;

$total->addTotalAmount('plandiscount', -$discount);
$total->addBaseTotalAmount('plandiscount', -$baseDiscount);
$total->setPlanDiscount(-$discount);
$total->setBasePlanDiscount(-$baseDiscount);
$quote->setGrandTotal($total->getGrandTotal() - $discount);
$quote->setBaseGrandTotal($total->getBaseGrandTotal() - $baseDiscount);

$quote->setPlanDiscount(-$discount);
$quote->setBasePlanDiscount(-$baseDiscount);

It is really strange that if the value is positive, it is working fine but in case of negative, it is adding 2 times.

Please try this way to applied custom discount

$discountAmount ="-10";
$appliedCartDiscount = $total->getDiscountAmount();

 $total->setDiscountAmount($discountAmount);
 $total->setBaseDiscountAmount($discountAmount);
 $total->setSubtotalWithDiscount($total->getSubtotal() + $discountAmount);
 $total->setBaseSubtotalWithDiscount($total->getBaseSubtotal() + $discountAmount);

 if(isset($appliedCartDiscount))
 
 $total->addTotalAmount('plandiscount', $discountAmount - $appliedCartDiscount);
 $total->addBaseTotalAmount('plandiscount', $discountAmount - $appliedCartDiscount);
 
 else 
 
 $total->addTotalAmount('plandiscount', $discountAmount);
 $total->addBaseTotalAmount('plandiscount', $discountAmount);