Issue #3243548 by valic: Add support for OpenExchangeRate

<?php

namespace Drupal\commerce_exchanger\Plugin\Commerce\ExchangerProvider;

use Drupal\Component\Serialization\Json;

/**

 * Provides the Open Exchange Rates API integration.

 *

 * @CommerceExchangerProvider(

 *   id = "open_exchange_rates",

 *   label = "Open Exchange Rates",

 *   display_label = "Open Exchange Rates",

 *   historical_rates = TRUE,

 *   enterprise = TRUE,

 *   api_key= TRUE,

 * )

 */

class OpenExchangeRatesExchanger extends ExchangerProviderRemoteBase {

  /**

   * {@inheritdoc}

   */

  public function apiUrl() {

    return 'https://openexchangerates.org/api/latest.json';

  }

  /**

   * {@inheritdoc}

   */

  public function getRemoteData($base_currency = NULL) {

    $data = NULL;

    $options = [

      'query' => ['app_id' => $this->getApiKey()],

    ];

    // Add base currency if we use enterprise model.

    if (!empty($base_currency) && $this->isEnterprise()) {

      $options['query']['base'] = $base_currency;

    }

    $request = $this->apiClient($options);

    if ($request) {

      $json = Json::decode($request);

      if (!empty($json['rates'])) {

        unset($json['timestamp'], $json['license'], $json['disclaimer']);

        // This structure is what we need.

        $data = $json;

      }

    }

    return $data;

  }

}