adding app/library/OAuth/Adapter classes (interface and League adapter)

app/library/OAuth/Adapter/League.php

@@ -0,0 +1,73 @@
+<?php
+
+namespace Httpcb\OAuth\Adapter;
+
+use League\OAuth2\Client\Provider\AbstractProvider,
+    League\OAuth2\Client\Token\AccessToken;
+
+class League implements AdapterInterface
+{
+    /**
+     * @var AbstractProvider
+     */
+    protected $_provider;
+
+    /**
+     * @var AccessToken
+     */
+    protected $_accessToken;
+
+    /**
+     * {@inheritDoc}
+     * @throws Exception
+     */
+    public function __construct($provider_name, $options)
+    {
+        $provider_name = ucfirst($provider_name);
+
+        $className = 'League\OAuth2\Client\Provider\\' . $provider_name;
+        $provider = new $className($options);
+
+        if (!($provider instanceof AbstractProvider)) {
+            // TODO: Throw a better exception class :)
+            throw new Exception("Provider object must be an instance of League\\OAuth2\\Client\\Provider\\AbstractProvider");
+        }
+
+        $this->_provider = $provider;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getProviderName()
+    {
+        return (new \ReflectionClass($this->_provider))->getShortName();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getAuthorizationUrl()
+    {
+        return $this->_provider->getAuthorizationUrl();
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function fetchAccessToken($code)
+    {
+        $this->_accessToken = $this->_provider->getAccessToken('authorization_code', [
+            'code' => $code
+        ]);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    public function getResourceData()
+    {
+        $resource = $this->_provider->getResourceOwner($this->_accessToken);
+        return $resource->toArray();
+    }
+}