<?php

declare(strict_types=1);

namespace Opencart\Catalog\Controller\Extension\PayAnyWay\Payment;

require_once DIR_EXTENSION . '/payanyway/catalog/library/payanyway/traits/payanyway.php';

/**
 * @property \Opencart\System\Engine\Config $config
 */
class Callback extends \Opencart\System\Engine\Controller
{
	use \Opencart\Catalog\Library\Extension\PayAnyWay\Traits\PayAnyWay;

	private const INVENTORY_ITEM_NAME_MAX_LENGTH = 128;
	private const INVENTORY_ITEM_DEFAULT_VAT_TAG = '1105';
	private const INVENTORY_ITEM_DEFAULT_PAYMENT_METHOD = 'full_payment';
	private const INVENTORY_ITEM_DEFAULT_PAYMENT_OBJECT = 'commodity';
	private const INVENTORY_ITEM_DEFAULT_MEASURE = 'unit';

	private const CANCEL_ORDER_STATUS_IDS = [7, 9, 16];

	private int $mntId;
	private string $integrityCode;
	private string $server;
	private string $vatRate;
	private string $currency;
	private int $pendingOrderStatusId;
	private int $successOrderStatusId;
	private int $errorOrderStatusId;
	private int $geoZoneId;
	private int $sortOrder;
	private string $cmsModuleVersion;

	private array $callbackData = [];
	private ?int $orderId;
	private array $orderInfo = [];

	public function __construct(\Opencart\System\Engine\Registry $registry)
	{
		parent::__construct($registry);

		if (!$this->validateOrder()) {
			$this->sendResponse('FAIL');
		}

		$this->initializeModule();
		$this->initializeCallbackData();
	}

	/** @throws \Exception */
	public function index(): void
	{
		($this->callbackData['MNT_COMMAND'] === 'CHECK')
			? $this->handleCheckCallback()
			: $this->handlePayCallback();
	}

	private function initializeCallbackData(): void
	{
		$requestData = ($_SERVER['REQUEST_METHOD'] === 'POST') ? $_POST : $_GET;

		$this->callbackData = [
			'MNT_COMMAND' => $this->getOptionalStringWithDefault($requestData, 'MNT_COMMAND'),
			'MNT_ID' => $this->getRequiredString($requestData, 'MNT_ID'),
			'MNT_TRANSACTION_ID' => $this->getRequiredString($requestData, 'MNT_TRANSACTION_ID'),
			'MNT_OPERATION_ID' => $this->getOptionalStringWithDefault($requestData, 'MNT_OPERATION_ID'),
			'MNT_AMOUNT' => $this->getOptionalStringWithDefault($requestData, 'MNT_AMOUNT'),
			'MNT_CURRENCY_CODE' => $this->getRequiredString($requestData, 'MNT_CURRENCY_CODE'),
			'MNT_SUBSCRIBER_ID' => $this->getOptionalStringWithDefault($requestData, 'MNT_SUBSCRIBER_ID'),
			'MNT_TEST_MODE' => $this->getRequiredString($requestData, 'MNT_TEST_MODE'),
			'MNT_SIGNATURE' => $this->getRequiredString($requestData, 'MNT_SIGNATURE'),
		];
	}

	private function sendResponse(string $response, int $statusCode = 200): void
	{
		http_response_code($statusCode);

		$isXml = str_starts_with($response, '<?xml') || str_contains($response, '<MNT_RESPONSE');
		header('Content-Type: ' . ($isXml ? 'application/xml' : 'text/plain; charset=UTF-8'));

		echo $response;
		exit;
	}

	/** @throws \Exception */
	private function handleCheckCallback(): void
	{
		if (!$this->checkSignature($this->callbackData)) {
			$this->sendResponse('FAIL');
		}

		$this->load->model('account/order');
		$products = $this->model_account_order->getProducts($this->orderId);
		$deliveryPrice = $this->getDeliveryPrice();

		$xmlData = [
			'MNT_ID' => $this->mntId,
			'MNT_TRANSACTION_ID' => $this->callbackData['MNT_TRANSACTION_ID'],
			'MNT_AMOUNT' => $this->formatPrice((float)($this->orderInfo['total'] ?? 0)),
			'MNT_CURRENCY_CODE' => $this->callbackData['MNT_CURRENCY_CODE'],
			'inventory' => $this->getInventoryJson($products) ?: null,
			'client' => $this->callbackData['MNT_SUBSCRIBER_ID'],
			'sno' => null,
			'delivery' => (null !== $deliveryPrice) ? $this->formatPrice($deliveryPrice) : null,
		];

		[$xmlData['MNT_RESULT_CODE'], $xmlData['MNT_DESCRIPTION']] = $this->determineCheckResult();

		$xmlData['MNT_SIGNATURE'] = md5(
			$xmlData['MNT_RESULT_CODE'] .
			$xmlData['MNT_ID'] .
			$xmlData['MNT_TRANSACTION_ID'] .
			$this->integrityCode,
		);

		$this->sendResponse($this->buildXMLResponse($xmlData));
	}

	/** @throws \Exception */
	private function determineCheckResult(): array
	{
		$orderStatusId = isset($this->orderInfo['order_status_id']) ? (int)$this->orderInfo['order_status_id'] : null;
		if (null === $orderStatusId) {
			return [500, "Order status not set"];
		}
		$orderStatus = $this->getOrderStatusById($orderStatusId);

		if (empty($this->callbackData['MNT_AMOUNT'])) {
			return [100, "Order status is '{$orderStatus}'"];
		}

		if ($this->successOrderStatusId === $orderStatusId) {
			return [200, 'Order Paid'];
		}

		if (in_array($orderStatusId, self::CANCEL_ORDER_STATUS_IDS, true)) {
			return [500, "Order status is '{$orderStatus}'"];
		}

		return [402, 'Order created, but not paid'];
	}

	/** @throws \Exception */
	private function handlePayCallback(): void
	{
		$shopData = [
			'MNT_ID' => $this->mntId,
			'MNT_TRANSACTION_ID' => $this->callbackData['MNT_TRANSACTION_ID'],
			'MNT_OPERATION_ID' => $this->callbackData['MNT_OPERATION_ID'],
			'MNT_AMOUNT' => $this->formatPrice((float)$this->orderInfo['total']),
			'MNT_CURRENCY_CODE' => $this->orderInfo['currency_code'],
			'MNT_SUBSCRIBER_ID' => $this->callbackData['MNT_SUBSCRIBER_ID'],
			'MNT_TEST_MODE' => $this->callbackData['MNT_TEST_MODE'],
		];

		if (!$this->checkSignature($shopData)) {
			$this->sendResponse('FAIL');
		}

		$isPayedOrder = $this->isOrderPaid();
		$resultCode = 200;

		$this->load->model('account/order');
		$products = $this->model_account_order->getProducts($this->orderId);
		$deliveryPrice = $this->getDeliveryPrice();

		$xmlData = [
			'MNT_ID' => $this->mntId,
			'MNT_TRANSACTION_ID' => $this->callbackData['MNT_TRANSACTION_ID'],
			'MNT_RESULT_CODE' => $resultCode,
			'MNT_SIGNATURE' => md5($resultCode . $this->mntId . $this->callbackData['MNT_TRANSACTION_ID'] . $this->integrityCode),
			'MNT_AMOUNT' => $this->callbackData['MNT_AMOUNT'],
			'MNT_CURRENCY_CODE' => $this->callbackData['MNT_CURRENCY_CODE'],
			'MNT_DESCRIPTION' => $isPayedOrder ? 'Order already paid' : 'Order success paid',
			'inventory' => $this->getInventoryJson($products),
			'client' => $this->callbackData['MNT_SUBSCRIBER_ID'],
			'sno' => null,
			'delivery' => $deliveryPrice !== null ? $this->formatPrice($deliveryPrice) : null,
		];

		if (!$isPayedOrder) {
			$this->load->language('extension/payanyway/payment/payanyway');
			$this->addOrderHistory($this->orderId, $this->successOrderStatusId, $this->language->get('text_payment_completed'),);
		}

		$this->sendResponse($this->buildXMLResponse($xmlData));
	}

	private function isOrderPaid(): bool
	{
		return $this->successOrderStatusId === (int)$this->orderInfo['order_status_id'];
	}

	/** @param array<string, mixed> $data */
	private function checkSignature(array $data): bool
	{
		$baseFields = [
			'MNT_ID',
			'MNT_TRANSACTION_ID',
			'MNT_OPERATION_ID',
			'MNT_AMOUNT',
			'MNT_CURRENCY_CODE',
			'MNT_SUBSCRIBER_ID',
			'MNT_TEST_MODE',
		];

		$fields = isset($data['MNT_COMMAND']) && ('CHECK' === $data['MNT_COMMAND'])
			? array_merge(['MNT_COMMAND'], $baseFields)
			: $baseFields;

		$signatureString = array_reduce($fields, static function ($carry, $field) use ($data) {
				return $carry . $data[$field];
			}, '') . $this->integrityCode;

		return hash_equals(md5($signatureString), $this->callbackData['MNT_SIGNATURE']);
	}

	private function getDeliveryPrice(): ?float
	{
		$this->load->model('account/order');
		foreach ($this->model_account_order->getTotals($this->orderId) as $orderTotal) {
			if (($orderTotal['code'] ?? '') === 'shipping') {
				$deliveryPrice = (float)($orderTotal['value'] ?? 0);
				return $deliveryPrice !== 0.0 ? $deliveryPrice : null;
			}
		}

		return null;
	}

	/**
	 * @param array<string, mixed> $products
	 * @return false|string
	 */
	private function getInventoryJson(array $products): false|string
	{
		$inventory = [];
		foreach ($products as $product) {
			$inventory[] = [
				'name' => $this->validateString($product['name'] ?? '', self::INVENTORY_ITEM_NAME_MAX_LENGTH),
				'price' => $this->formatPrice((float)($product['price'] ?? 0)),
				'quantity' => $this->formatQuantity((string)($product['quantity'] ?? '0')),
				'vatTag' => $this->vatRate,
				'pm' => self::INVENTORY_ITEM_DEFAULT_PAYMENT_METHOD,
				'po' => self::INVENTORY_ITEM_DEFAULT_PAYMENT_OBJECT,
				'measure' => self::INVENTORY_ITEM_DEFAULT_MEASURE,
			];
		}

		return json_encode($inventory, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
	}

	/**
	 * @param int $orderStatusId
	 * @return string
	 * @throws \Exception
	 */
	public function getOrderStatusById(int $orderStatusId): string
	{
		$this->load->model('localisation/order_status');
		/**@var array<int, array{order_status_id: string, name: string}> $orderStatuses */
		$orderStatuses = $this->model_localisation_order_status->getOrderStatuses();

		$orderStatus = 'unknown';
		foreach ($orderStatuses as $orderStatus) {
			$statusId = isset($orderStatus['order_status_id']) ? (int)$orderStatus['order_status_id'] : null;
			if ($statusId === $orderStatusId) {
				$orderStatus = $orderStatus['name'];
				break;
			}
		}

		return $orderStatus;
	}

	private function formatQuantity(string $quantity): string
	{
		$quantity = str_replace(',', '.', $quantity);

		if (!str_contains($quantity, '.') && ctype_digit($quantity)) {
			return (string)(int)$quantity;
		}

		return number_format((float)$quantity, 3, '.', '');
	}

	/**
	 * @param array<string, mixed> $data
	 * @throws \Exception
	 */
	private function buildXMLResponse(array $data): false|string
	{
		$dom = new \DOMDocument('1.0', 'UTF-8');
		$dom->formatOutput = false;

		$root = $dom->createElement('MNT_RESPONSE');
		$dom->appendChild($root);

		$requiredFields = [
			'MNT_ID',
			'MNT_TRANSACTION_ID',
			'MNT_RESULT_CODE',
			'MNT_DESCRIPTION',
			'MNT_AMOUNT',
			'MNT_CURRENCY_CODE',
			'MNT_SIGNATURE',
		];

		foreach ($requiredFields as $field) {
			if (isset($data[$field]) && ($data[$field] !== '')) {
				$root->appendChild($dom->createElement($field, (string)$data[$field]));
			}
		}

		$attributes = $dom->createElement('MNT_ATTRIBUTES');
		$root->appendChild($attributes);

		$attributeMap = [
			'INVENTORY' => $data['inventory'] ?? null,
			'CLIENT' => $data['client'] ?? null,
			'SNO' => $data['sno'] ?? null,
			'DELIVERY' => $data['delivery'] ?? null,
		];

		foreach ($attributeMap as $key => $value) {
			if (!empty($value)) {
				$attrElement = $dom->createElement('ATTRIBUTE');
				$attrElement->appendChild($dom->createElement('KEY', $key));
				$attrElement->appendChild($dom->createElement('VALUE', (string)$value));
				$attributes->appendChild($attrElement);
			}
		}

		return $dom->saveXML();
	}

	/** @param array<string, mixed> $params */
	private function getOptionalStringWithDefault(array $params, string $key, string $default = ''): string
	{
		return $this->getOptionalString($params, $key) ?? $default;
	}

	/** @param array<string, mixed> $params */
	private function getOptionalString(array $params, string $key): ?string
	{
		$value = $params[$key] ?? null;
		if (!is_string($value) || trim($value) === '') {
			return null;
		}

		return $value;
	}

	/**
	 * @param array<string, mixed> $params
	 * @throws \InvalidArgumentException
	 */
	private function getRequiredString(array $params, string $key): string
	{
		if (!isset($params[$key])) {
			throw new \InvalidArgumentException('Missing required field: ' . $key);
		}

		$value = $params[$key];
		if (!is_string($value)) {
			throw new \InvalidArgumentException(
				sprintf('Field "%s" must be a string, %s given', $key, gettype($value)),
			);
		}

		if ('' === $value) {
			throw new \InvalidArgumentException(sprintf('Field "%s" must be a non-empty string', $key));
		}

		return $value;
	}
}