OpenCart 🇺🇦

if (isset($this->session->data['reward'])) {
	$this->language->load('total/reward');

	$points = $this->customer->getRewardPoints();

	if ($this->session->data['reward'] <= $points) {
		$discount_total = 0;

		$points_total = 0;

		foreach ($this->cart->getProducts() as $product) {
			if ($product['points']) {
				$points_total += $product['points'];
			}
		}	

		$points = min($points, $points_total);

		foreach ($this->cart->getProducts() as $product) {
			$discount = 0;

			if ($product['points']) {
				$discount = $product['total'] * ($this->session->data['reward'] / $points_total);

				if ($product['tax_class_id']) {
					$tax_rates = $this->tax->getRates($product['total'] - ($product['total'] - $discount), $product['tax_class_id']);

					foreach ($tax_rates as $tax_rate) {
						if ($tax_rate['type'] == 'P') {
							$taxes[$tax_rate['tax_rate_id']] -= $tax_rate['amount'];
						}
					}	
				}
			}

			$discount_total += $discount;
		}

		$total_data[] = array(
			'code'       => 'reward',
			'title'      => sprintf($this->language->get('text_reward'), $this->session->data['reward']),
			'text'       => $this->currency->format(-$discount_total),
			'value'      => -$discount_total,
			'sort_order' => $this->config->get('reward_sort_order')
		);

		$total -= $discount_total;
	} 
}