TransactionPayment.php

<?php
/**
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 *
 * Adyen Payment module (https://www.adyen.com/)
 *
 * Copyright (c) 2015 Adyen BV (https://www.adyen.com/)
 * See LICENSE.txt for license details.
 *
 * Author: Adyen <magento@adyen.com>
 */

namespace Adyen\Payment\Gateway\Http\Client;

use Magento\Payment\Gateway\Http\ClientInterface;
use Adyen\Payment\Model\ApplicationInfo;

/**
 * Class TransactionPayment
 */
class TransactionPayment implements ClientInterface
{

    /**
     * @var \Adyen\Payment\Helper\Data
     */
    private $adyenHelper;

    /**
     * @var ApplicationInfo
     */
    private $applicationInfo;

    /**
     * TransactionPayment constructor.
     * @param \Adyen\Payment\Helper\Data $adyenHelper
     * @param ApplicationInfo $applicationInfo
     */
    public function __construct(
        \Adyen\Payment\Helper\Data $adyenHelper,
        \Adyen\Payment\Model\ApplicationInfo $applicationInfo
    ) {
        $this->adyenHelper = $adyenHelper;
        $this->applicationInfo = $applicationInfo;
    }

    /**
     * @param \Magento\Payment\Gateway\Http\TransferInterface $transferObject
     * @return array|mixed|string
     * @throws \Adyen\AdyenException
     */
    public function placeRequest(\Magento\Payment\Gateway\Http\TransferInterface $transferObject)
    {
        $request = $transferObject->getBody();
        $headers = $transferObject->getHeaders();

        // If the payments call is already done return the request
        if (!empty($request['resultCode'])) {
            //Initiate has already a response
            return $request;
        }

        $client = $this->adyenHelper->initializeAdyenClient();

        $service = new \Adyen\Service\Checkout($client);

        $requestOptions = [];

        if (!empty($headers['idempotencyKey'])) {
            $requestOptions['idempotencyKey'] = $headers['idempotencyKey'];
        }

        $request = $this->applicationInfo->addMerchantApplicationIntoRequest($request);

        try {
            $response = $service->payments($request, $requestOptions);
        } catch (\Adyen\AdyenException $e) {
            $response['error'] = $e->getMessage();
        }

        return $response;
    }
}