Integrating the Easy Credit payment method for Heidelpay

$config[OmsConstants::PROCESS_LOCATION] = [
	...
	APPLICATION_ROOT_DIR . '/vendor/spryker-eco/heidelpay/config/Zed/Oms',
];
$config[OmsConstants::ACTIVE_PROCESSES] = [
	...
	'HeidelpayEasyCredit01',
];
$config[SalesConstants::PAYMENT_METHOD_STATEMACHINE_MAPPING] = [
	...
	HeidelpayConfig::PAYMENT_METHOD_EASY_CREDIT => 'HeidelpayEasyCredit01',
];

<?php

namespace Pyz\Yves\CheckoutPage\Process;

use Pyz\Yves\CheckoutPage\CheckoutPageDependencyProvider;
use Pyz\Yves\CheckoutPage\Plugin\Provider\CheckoutPageControllerProvider;
use Spryker\Yves\StepEngine\Process\StepCollection;
use SprykerEco\Client\Heidelpay\HeidelpayClientInterface;
use SprykerEco\Yves\Heidelpay\CheckoutPage\Process\Steps\HeidelpayEasycreditInitializeStep;
use SprykerEco\Yves\Heidelpay\CheckoutPage\Process\Steps\HeidelpayEasycreditStep;
use SprykerShop\Yves\CheckoutPage\Process\StepFactory as BaseStepFactory;
use SprykerShop\Yves\HomePage\Plugin\Provider\HomePageControllerProvider;

/**
 * @method \SprykerShop\Yves\CheckoutPage\CheckoutPageConfig getConfig()
 */
class StepFactory extends BaseStepFactory
{
	/**
	 * @return \Spryker\Yves\StepEngine\Process\StepCollectionInterface
	 */
	public function createStepCollection()
	{
		$stepCollection = new StepCollection(
			$this->getUrlGenerator(),
			CheckoutPageControllerProvider::CHECKOUT_ERROR
		);

		$stepCollection
			->addStep($this->createEntryStep())
			->addStep($this->createCustomerStep())
			->addStep($this->createAddressStep())
			->addStep($this->createShipmentStep())
			->addStep($this->createHeidelpayEasyCreditInitializeStep())
			->addStep($this->createPaymentStep())
			->addStep($this->createHeidelpayEasyCreditStep())
			->addStep($this->createSummaryStep())
			->addStep($this->createPlaceOrderStep())
			->addStep($this->createSuccessStep());

		return $stepCollection;
	}

	/**
	 * @return \SprykerEco\Yves\Heidelpay\CheckoutPage\Process\Steps\HeidelpayEasycreditInitializeStep
	 */
	public function createHeidelpayEasyCreditInitializeStep(): HeidelpayEasycreditInitializeStep
	{
		return new HeidelpayEasycreditInitializeStep(
			CheckoutPageControllerProvider::CHECKOUT_EASYCREDIT_INITIALIZE,
			HomePageControllerProvider::ROUTE_HOME,
			$this->getHeidelpayClient()
		);
	}

	/**
	 * @return \SprykerEco\Yves\Heidelpay\CheckoutPage\Process\Steps\HeidelpayEasycreditStep
	 */
	public function createHeidelpayEasyCreditStep(): HeidelpayEasycreditStep
	{
		return new HeidelpayEasycreditStep(
			CheckoutPageControllerProvider::CHECKOUT_EASYCREDIT,
			HomePageControllerProvider::ROUTE_HOME
		);
	}

	/**
	 * @return \SprykerEco\Client\Heidelpay\HeidelpayClientInterface
	 */
	public function getHeidelpayClient(): HeidelpayClientInterface
	{
		return $this->getProvidedDependency(CheckoutPageDependencyProvider::CLIENT_HEIDELPAY);
	}
}

<?php

namespace Pyz\Yves\CheckoutPage;

use Pyz\Yves\CheckoutPage\Process\StepFactory;
use SprykerShop\Yves\CheckoutPage\CheckoutPageFactory as SprykerShopCheckoutPageFactory;

class CheckoutPageFactory extends SprykerShopCheckoutPageFactory
{
	/**
	 * @return \Pyz\Yves\CheckoutPage\Process\StepFactory
	 */
	public function createStepFactory()
	{
		return new StepFactory();
	}
}

<?php

namespace Pyz\Yves\CheckoutPage\Controller;

use SprykerShop\Yves\CheckoutPage\Controller\CheckoutController as BaseCheckoutController;
use Symfony\Component\HttpFoundation\Request;

/**
 * @method \SprykerShop\Yves\CheckoutPage\CheckoutPageFactory getFactory()
 */
class CheckoutController extends BaseCheckoutController
{
	/**
	 * @param \Symfony\Component\HttpFoundation\Request $request
	 *
	 * @return array|\Symfony\Component\HttpFoundation\RedirectResponse
	 */
	public function easyCreditAction(Request $request)
	{
		return $this->createStepProcess()->process($request);
	}
}

<?php

namespace Pyz\Yves\CheckoutPage\Plugin\Provider;

use Spryker\Yves\Router\Route\RouteCollection;
use SprykerShop\Yves\CheckoutPage\Plugin\Router\CheckoutPageRouteProviderPlugin as SprykerShopCheckoutPageRouteProviderPlugin;

class CheckoutPageRouteProviderPlugin extends SprykerShopCheckoutPageRouteProviderPlugin
{
    public const ROUTE_NAME_CHECKOUT_EASYCREDIT = 'checkout-easycredit';
    public const ROUTE_NAME_CHECKOUT_EASYCREDIT_INITIALIZE = 'checkout-easycredit-initialize';

    /**
     * Specification:
     * - Adds Routes to the RouteCollection.
     *
     * @api
     *
     * @param \Spryker\Yves\Router\Route\RouteCollection $routeCollection
     *
     * @return \Spryker\Yves\Router\Route\RouteCollection
     */
    public function addRoutes(RouteCollection $routeCollection): RouteCollection
    {
	$route = $this->buildRoute('/checkout/easycredit', 'CheckoutPage', 'Checkout', 'easyCreditAction');
        $routeCollection->add(static::ROUTE_NAME_CHECKOUT_EASYCREDIT, $route);

	$route = $this->buildRoute('/checkout/easycredit-initialize', 'CheckoutPage', 'Checkout', 'easyCreditAction');
        $routeCollection->add(static::ROUTE_NAME_CHECKOUT_EASYCREDIT_INITIALIZE, $route);

        return $routeCollection;
    }
}

<?php

namespace Pyz\Yves\CheckoutPage;

...
use SprykerEco\Yves\Heidelpay\Plugin\Subform\HeidelpayEasyCreditSubFormPlugin;
...

class CheckoutPageDependencyProvider extends SprykerShopCheckoutPageDependencyProvider
{
	public const CLIENT_HEIDELPAY = 'CLIENT_HEIDELPAY';

	/**
	 * @param \Spryker\Yves\Kernel\Container $container
	 *
	 * @return \Spryker\Yves\Kernel\Container
	 */
	public function provideDependencies(Container $container)
	{
		$container = parent::provideDependencies($container);
		$container = $this->addHeidelpayClient($container);

		return $container;
	}

	/**
	 * @param \Spryker\Yves\Kernel\Container $container
	 *
	 * @return \Spryker\Yves\Kernel\Container
	 */
	protected function addSubFormPluginCollection(Container $container): Container
	{
		$container[self::PAYMENT_SUB_FORMS] = function () {
			$subFormPluginCollection = new SubFormPluginCollection();
			...
			$subFormPluginCollection->add(new HeidelpayEasyCreditSubFormPlugin());

			return $subFormPluginCollection;
		};

		return $container;
	}

	/**
	 * @param \Spryker\Yves\Kernel\Container $container
	 *
	 * @return \Spryker\Yves\Kernel\Container
	 */
	protected function addPaymentMethodHandlerPluginCollection(Container $container): Container
	{
		$container[self::PAYMENT_METHOD_HANDLER] = function () {
			$stepHandlerPluginCollection = new StepHandlerPluginCollection();
			...
			$stepHandlerPluginCollection->add(new HeidelpayHandlerPlugin(), PaymentTransfer::HEIDELPAY_EASY_CREDIT);

			return $stepHandlerPluginCollection;
		};

		return $container;
	}

	/**
	 * @param \Spryker\Yves\Kernel\Container $container
	 *
	 * @return \Spryker\Yves\Kernel\Container
	 */
	protected function addHeidelpayClient(Container $container): Container
	{
		$container[static::CLIENT_HEIDELPAY] = function () use ($container) {
			return $container->getLocator()->heidelpay()->client();
		};

		return $container;
	}
}