Add Google authentication

vendor/OAuth/OAuth2/Service/ServiceInterface.php

@@ -0,0 +1,37 @@
+<?php
+
+namespace OAuth\OAuth2\Service;
+
+use OAuth\Common\Consumer\CredentialsInterface;
+use OAuth\Common\Storage\TokenStorageInterface;
+use OAuth\Common\Token\TokenInterface;
+use OAuth\Common\Http\Client\ClientInterface;
+use OAuth\Common\Http\Exception\TokenResponseException;
+use OAuth\Common\Service\ServiceInterface as BaseServiceInterface;
+use OAuth\Common\Http\Uri\UriInterface;
+
+/**
+ * Defines the common methods across OAuth 2 services.
+ */
+interface ServiceInterface extends BaseServiceInterface
+{
+    /**
+     * Authorization methods for various services
+     */
+    const AUTHORIZATION_METHOD_HEADER_OAUTH    = 0;
+    const AUTHORIZATION_METHOD_HEADER_BEARER   = 1;
+    const AUTHORIZATION_METHOD_QUERY_STRING    = 2;
+    const AUTHORIZATION_METHOD_QUERY_STRING_V2 = 3;
+    const AUTHORIZATION_METHOD_QUERY_STRING_V3 = 4;
+
+    /**
+     * Retrieves and stores/returns the OAuth2 access token after a successful authorization.
+     *
+     * @param string $code The access code from the callback.
+     *
+     * @return TokenInterface $token
+     *
+     * @throws TokenResponseException
+     */
+    public function requestAccessToken($code);
+}