thephpleague · Nyholm · Jul 19, 2016 · Jul 19, 2016
diff --git a/README.UPGRADING.md b/README.UPGRADING.md
@@ -2,6 +2,6 @@
 
 ## Upgrade Guide
 
-### Upgrading to Version 1.0.0
+### Upgrading to Version 1.5
 
-TBD
+You need to install `php-http/guzzle6-adapter` and ` php-http/message`, then use the libaray as normal.
diff --git a/README.md b/README.md
@@ -249,9 +249,17 @@ $provider = new \League\OAuth2\Client\Provider\GenericProvider([
 Via Composer
 
 ``` bash
-$ composer require league/oauth2-client
+$ composer require league/oauth2-client php-http/guzzle6-adapter php-http/message
 ```
 
+The two extra packages from `php-http` is part of the [HTTPlug](http://httplug.io/) organisation. It helps us not to 
+be coupled to Guzzle. That is why you need to install the `php-http/guzzle6-adapter` or any other library providing the virtual 
+[php-http/client-implementation](https://packagist.org/providers/php-http/client-implementation) package. The 
+`php-http/message` package contains factory classes to create Guzzle and Diactoros PSR-7 requests. 
+
+You can read more about HTTPlug and how to use it in 
+[their documentation](http://docs.php-http.org/en/latest/httplug/users.html).
+
 ## Contributing
 
 Please see [CONTRIBUTING](https://github.com/thephpleague/oauth2-client/blob/master/CONTRIBUTING.md) for details.

diff --git a/composer.json b/composer.json
@@ -4,15 +4,21 @@
     "license": "MIT",
     "require": {
         "php": ">=5.5.0",
+        "psr/http-message": "^1.0",
         "ext-curl": "*",
         "ircmaxell/random-lib": "~1.1",
-        "guzzlehttp/guzzle": "~6.0"
+        "php-http/httplug": "^1.0",
+        "php-http/client-implementation": "^1.0",
+        "php-http/message-factory": "^1.0.2",
+        "php-http/discovery": "^1.0"
     },
     "require-dev": {
         "phpunit/phpunit": "~4.0",
         "mockery/mockery": "~0.9",
         "squizlabs/php_codesniffer": "~2.0",
         "satooshi/php-coveralls": "0.6.*",
+        "php-http/message": "^1.0",
+        "php-http/guzzle6-adapter": "^1.0",
         "jakub-onderka/php-parallel-lint": "0.8.*"
     },
     "keywords": [

diff --git a/src/Provider/AbstractProvider.php b/src/Provider/AbstractProvider.php
@@ -14,9 +14,11 @@
 
 namespace League\OAuth2\Client\Provider;
 
-use GuzzleHttp\Client as HttpClient;
-use GuzzleHttp\ClientInterface as HttpClientInterface;
-use GuzzleHttp\Exception\BadResponseException;
+use GuzzleHttp\ClientInterface as GuzzleClientInterface;
+use GuzzleHttp\Client as GuzzleClient;
+use Http\Adapter\Guzzle6\Client as HttplugGuzzle6;
+use Http\Client\HttpClient;
+use Http\Discovery\HttpClientDiscovery;
 use League\OAuth2\Client\Grant\AbstractGrant;
 use League\OAuth2\Client\Grant\GrantFactory;
 use League\OAuth2\Client\Provider\Exception\IdentityProviderException;
@@ -85,7 +87,7 @@ abstract class AbstractProvider
     protected $requestFactory;
 
     /**
-     * @var HttpClientInterface
+     * @var \Http\Client\HttpClient
      */
     protected $httpClient;
 
@@ -94,6 +96,20 @@ abstract class AbstractProvider
      */
     protected $randomFactory;
 
+    /**
+     * The options given to the Guzzle6 client
+     * @var array
+     * @deprecated These are to be removed in the next major release.
+     *      These options are only used in getHttpClient to keep BC.
+     */
+    private $guzzle6Options = [];
+
+    /**
+     * @var GuzzleClientInterface
+     * @deprecated This client is only used in getHttpClient to keep BC.
+     */
+    private $guzzleClient;
+
     /**
      * Constructs an OAuth 2.0 service provider.
      *
@@ -123,14 +139,7 @@ public function __construct(array $options = [], array $collaborators = [])
         }
         $this->setRequestFactory($collaborators['requestFactory']);
 
-        if (empty($collaborators['httpClient'])) {
-            $client_options = $this->getAllowedClientOptions($options);
-
-            $collaborators['httpClient'] = new HttpClient(
-                array_intersect_key($options, array_flip($client_options))
-            );
-        }
-        $this->setHttpClient($collaborators['httpClient']);
+        $this->setHttpClient($this->getHttpClientFromOptions($options, $collaborators));
 
         if (empty($collaborators['randomFactory'])) {
             $collaborators['randomFactory'] = new RandomFactory();
@@ -207,11 +216,44 @@ public function getRequestFactory()
     /**
      * Sets the HTTP client instance.
      *
-     * @param  HttpClientInterface $client
+     * @param  HttpClient $client
      * @return self
      */
-    public function setHttpClient(HttpClientInterface $client)
+    public function setHttpClient($client)
     {
+        if ($client instanceof GuzzleClientInterface) {
+            @trigger_error(
+                sprintf(
+                    'Passing a "%s" to "%s::setHttpClient" is deprecated. Use a "Http\Client\HttpClient" instead.',
+                    GuzzleClientInterface::class,
+                    static::class
+                ),
+                E_USER_DEPRECATED
+            );
+            if (!class_exists(HttplugGuzzle6::class)) {
+                throw new \RuntimeException(
+                    sprintf(
+                        'You must install "php-http/guzzle6-adapter" to be able to pass a "%s" to "%s::setHttpClient".',
+                        GuzzleClientInterface::class,
+                        static::class
+                    )
+                );
+            }
+            $client = new HttplugGuzzle6($client);
+        }
+
+        if (!$client instanceof HttpClient) {
+            $type = is_object($client) ? get_class($client) : gettype($client);
+            throw new \RuntimeException(
+                sprintf(
+                    'First parameter to "%s::setHttpClient" was expected to be a "%s", you provided a "%s"',
+                    static::class,
+                    HttpClient::class,
+                    $type
+                )
+            );
+        }
+
         $this->httpClient = $client;
 
         return $this;
@@ -220,13 +262,43 @@ public function setHttpClient(HttpClientInterface $client)
     /**
      * Returns the HTTP client instance.
      *
-     * @return HttpClientInterface
+     * @return HttpClient
      */
-    public function getHttpClient()
+    public function getHttplugClient()
     {
         return $this->httpClient;
     }
 
+    /**
+     * Returns the HTTP client instance.
+     *
+     * @return GuzzleClientInterface
+     */
+    public function getHttpClient()
+    {
+        @trigger_error(
+            sprintf(
+                'Using "%s::getHttpClient" is deprecated in favor for "%s::getHttplugClient".',
+                static::class,
+                static::class
+            ),
+            E_USER_DEPRECATED
+        );
+
+        if ($this->guzzleClient !== null) {
+            return $this->guzzleClient;
+        }
+
+        if (!class_exists(GuzzleClient::class)) {
+            throw new \RuntimeException(
+                'You must install "php-http/guzzle6-adapter" to be able to use "%s::getHttplugClient".',
+                static::class
+            );
+        }
+
+        return new GuzzleClient($this->guzzle6Options);
+    }
+
     /**
      * Sets the instance of the CSPRNG random generator factory.
      *
@@ -621,12 +693,7 @@ protected function createRequest($method, $url, $token, array $options)
      */
     protected function sendRequest(RequestInterface $request)
     {
-        try {
-            $response = $this->getHttpClient()->send($request);
-        } catch (BadResponseException $e) {
-            $response = $e->getResponse();
-        }
-        return $response;
+        return $this->getHttplugClient()->sendRequest($request);
     }
 
     /**
@@ -840,4 +907,62 @@ public function getHeaders($token = null)
 
         return $this->getDefaultHeaders();
     }
+
+    /**
+     * Get a HttpClient from constructor options
+     *
+     * @param array $options
+     * @param array $collaborators
+     *
+     * @return HttpClient
+     */
+    private function getHttpClientFromOptions(array $options, array $collaborators)
+    {
+        if (!empty($collaborators['httplugClient'])) {
+            // Use provided client
+            return $collaborators['httplugClient'];
+        }
+
+        if (empty($collaborators['httpClient'])) {
+            $client_options = $this->getAllowedClientOptions($options);
+            $guzzle6Options = array_intersect_key($options, array_flip($client_options));
+
+            if (empty($guzzle6Options)) {
+                return HttpClientDiscovery::find();
+            } else {
+                @trigger_error(
+                    'Passing options to Guzzle6 client is deprecated. Use "httplugClient" instead',
+                    E_USER_DEPRECATED
+                );
+                if (!class_exists(HttplugGuzzle6::class)) {
+                    throw new \RuntimeException(
+                        'You must install "php-http/guzzle6-adapter" to be able to pass options to the Guzzle6 client.'
+                    );
+                }
+                $this->guzzle6Options = $guzzle6Options;
+
+                return HttplugGuzzle6::createWithConfig($guzzle6Options);
+            }
+        }
+
+        @trigger_error('The "httpClient" option is deprecated. Use "httplugClient" instead', E_USER_DEPRECATED);
+        $client = $collaborators['httpClient'];
+        if (!$client instanceof GuzzleClientInterface) {
+            throw new \RuntimeException(
+                sprintf(
+                    'The value provided with option "HttpClient" must be instance of "%s".',
+                    GuzzleClientInterface::class
+                )
+            );
+        }
+
+        if (!class_exists(HttplugGuzzle6::class)) {
+            throw new \RuntimeException(
+                'You must install "php-http/guzzle6-adapter" to pass a Guzzle6 client with the "httpClient" option.'
+            );
+        }
+
+        $this->guzzleClient = $client;
+        return new HttplugGuzzle6($client);
+    }
 }
diff --git a/src/Tool/RequestFactory.php b/src/Tool/RequestFactory.php
@@ -14,7 +14,9 @@
 
 namespace League\OAuth2\Client\Tool;
 
-use GuzzleHttp\Psr7\Request;
+use Http\Discovery\MessageFactoryDiscovery;
+use Psr\Http\Message\RequestInterface;
+use Psr\Http\Message\StreamInterface;
 
 /**
  * Used to produce PSR-7 Request instances.
@@ -23,6 +25,11 @@
  */
 class RequestFactory
 {
+    /**
+     * @var \Http\Message\RequestFactory
+     */
+    private $factory;
+
     /**
      * Creates a PSR-7 Request instance.
      *
@@ -32,7 +39,7 @@ class RequestFactory
      * @param  string|resource|StreamInterface $body Message body.
      * @param  string $version HTTP protocol version.
      *
-     * @return Request
+     * @return RequestInterface
      */
     public function getRequest(
         $method,
@@ -41,7 +48,11 @@ public function getRequest(
         $body = null,
         $version = '1.1'
     ) {
-        return new Request($method, $uri, $headers, $body, $version);
+        if (!$this->factory) {
+            $this->factory = MessageFactoryDiscovery::find();
+        }
+
+        return $this->factory->createRequest($method, $uri, $headers, $body, $version);
     }
 
     /**
@@ -70,7 +81,7 @@ protected function parseOptions(array $options)
      * @param  null|string $uri
      * @param  array $options
      *
-     * @return Request
+     * @return RequestInterface
      */
     public function getRequestWithOptions($method, $uri, array $options = [])
     {

diff --git a/test/src/Grant/GrantTestCase.php b/test/src/Grant/GrantTestCase.php
@@ -2,7 +2,7 @@
 
 namespace League\OAuth2\Client\Test\Grant;
 
-use GuzzleHttp\ClientInterface;
+use Http\Client\HttpClient;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\StreamInterface;
 use League\OAuth2\Client\Token\AccessToken;
@@ -44,7 +44,7 @@ abstract public function providerGetAccessToken();
     /**
      * Callback to test access token request parameters.
      *
-     * @return Closure
+     * @return \Closure
      */
     abstract protected function getParamExpectation();
 
@@ -64,8 +64,8 @@ public function testGetAccessToken($grant, array $params = [])
 
         $paramCheck = $this->getParamExpectation();
 
-        $client = m::mock(ClientInterface::class);
-        $client->shouldReceive('send')->with(
+        $client = m::mock(HttpClient::class);
+        $client->shouldReceive('sendRequest')->with(
             $request = m::on(function ($request) use ($paramCheck) {
                 parse_str((string) $request->getBody(), $body);
                 return $paramCheck($body);