Added complete purchase and purchase response

Author: vuongxuongminh

src/Message/CompletePurchaseResponse.php

@@ -0,0 +1,18 @@
+<?php
+/**
+ * @link https://github.com/phpviet/omnipay-onepay
+ *
+ * @copyright (c) PHP Viet
+ * @license [MIT](https://opensource.org/licenses/MIT)
+ */
+
+namespace Omnipay\OnePay\Message;
+
+/**
+ * @author Vuong Minh <[email protected]>
+ * @since 1.0.0
+ */
+class CompletePurchaseResponse extends AbstractSignatureResponse
+{
+
+}

src/Message/PurchaseResponse.php

@@ -0,0 +1,50 @@
+<?php
+/**
+ * @link https://github.com/phpviet/omnipay-onepay
+ *
+ * @copyright (c) PHP Viet
+ * @license [MIT](https://opensource.org/licenses/MIT)
+ */
+
+namespace Omnipay\OnePay\Message;
+
+use Omnipay\Common\Message\RedirectResponseInterface;
+
+/**
+ * @author Vuong Minh <[email protected]>
+ * @since 1.0.0
+ */
+class PurchaseResponse extends AbstractResponse implements RedirectResponseInterface
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function isSuccessful(): bool
+    {
+        return false;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getRedirectUrl(): string
+    {
+        return $this->data['redirect_url'];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function isRedirect(): bool
+    {
+        return true;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getTransactionId(): string
+    {
+        return $this->data['vpc_MerchTxnRef'];
+    }
+}