OpenCart 🇺🇦

$this->language->load('checkout/cart');

$json = array();

if (isset($this->request->post['product_id'])) {
	$product_id = $this->request->post['product_id'];
} else {
	$product_id = 0;
}

$this->load->model('catalog/product');

$product_info = $this->model_catalog_product->getProduct($product_id);

if ($product_info) {			
	if (isset($this->request->post['quantity'])) {
		$quantity = $this->request->post['quantity'];
	} else {
		$quantity = 1;
	}

	if (isset($this->request->post['option'])) {
		$option = array_filter($this->request->post['option']);
	} else {
		$option = array();	
	}

	if (isset($this->request->post['profile_id'])) {
		$profile_id = $this->request->post['profile_id'];
	} else {
		$profile_id = 0;
	}

	$product_options = $this->model_catalog_product->getProductOptions($this->request->post['product_id']);

	foreach ($product_options as $product_option) {
		if ($product_option['required'] && empty($option[$product_option['product_option_id']])) {
			$json['error']['option'][$product_option['product_option_id']] = sprintf($this->language->get('error_required'), $product_option['name']);
		}
	}

	$profiles = $this->model_catalog_product->getProfiles($product_info['product_id']);

	if ($profiles) {
		$profile_ids = array();

		foreach ($profiles as $profile) {
			$profile_ids[] = $profile['profile_id'];
		}

		if (!in_array($profile_id, $profile_ids)) {
			$json['error']['profile'] = $this->language->get('error_profile_required');
		}
	}

	if (!$json) {
		$this->cart->add($this->request->post['product_id'], $quantity, $option, $profile_id);

		$json['success'] = sprintf($this->language->get('text_success'), $this->url->link('product/product', 'product_id=' . $this->request->post['product_id']), $product_info['name'], $this->url->link('checkout/cart'));

		unset($this->session->data['shipping_method']);
		unset($this->session->data['shipping_methods']);
		unset($this->session->data['payment_method']);
		unset($this->session->data['payment_methods']);

		// Totals
		$this->load->model('setting/extension');

		$total_data = array();					
		$total = 0;
		$taxes = $this->cart->getTaxes();

		// Display prices
		if (($this->config->get('config_customer_price') && $this->customer->isLogged()) || !$this->config->get('config_customer_price')) {
			$sort_order = array(); 

			$results = $this->model_setting_extension->getExtensions('total');

			foreach ($results as $key => $value) {
				$sort_order[$key] = $this->config->get($value['code'] . '_sort_order');
			}

			array_multisort($sort_order, SORT_ASC, $results);

			foreach ($results as $result) {
				if ($this->config->get($result['code'] . '_status')) {
					$this->load->model('total/' . $result['code']);

					$this->{'model_total_' . $result['code']}->getTotal($total_data, $total, $taxes);
				}

				$sort_order = array(); 

				foreach ($total_data as $key => $value) {
					$sort_order[$key] = $value['sort_order'];
				}

				array_multisort($sort_order, SORT_ASC, $total_data);			
			}
		}

		$json['total'] = sprintf($this->language->get('text_items'), $this->cart->countProducts() + (isset($this->session->data['vouchers']) ? count($this->session->data['vouchers']) : 0), $this->currency->format($total));
	} else {
		$json['redirect'] = str_replace('&', '&', $this->url->link('product/product', 'product_id=' . $this->request->post['product_id']));
	}
}

$this->response->setOutput(json_encode($json));