Use client credentials

modules/ppcp-api-client/src/Authentication/ClientCredentials.php

@@ -0,0 +1,41 @@
+<?php
+/**
+ * The client credentials.
+ *
+ * @package WooCommerce\PayPalCommerce\ApiClient\Authentication
+ */
+
+declare(strict_types=1);
+
+namespace WooCommerce\PayPalCommerce\ApiClient\Authentication;
+
+use WooCommerce\PayPalCommerce\WcGateway\Settings\Settings;
+
+/**
+ * Class ClientCredentials
+ */
+class ClientCredentials {
+
+	/**
+	 * The settings.
+	 *
+	 * @var Settings
+	 */
+	protected $settings;
+
+	/**
+	 * ClientCredentials constructor.
+	 *
+	 * @param Settings $settings The settings.
+	 */
+	public function __construct(Settings $settings) {
+		$this->settings = $settings;
+	}
+
+	public function credentials(): string {
+		$client_id = $this->settings->has( 'client_id' ) ? $this->settings->get( 'client_id' ) : '';
+		$client_secret = $this->settings->has( 'client_secret' ) ? $this->settings->get( 'client_secret' ) : '';
+
+		return 'Basic ' . base64_encode($client_id . ':' . $client_secret);
+	}
+}