<?php
/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\authclient;

use yii\base\Action;
use yii\base\Exception;
use yii\base\InvalidConfigException;
use yii\base\NotSupportedException;
use yii\web\Response;
use yii\web\HttpException;
use yii\web\NotFoundHttpException;
use Yii;

/**
 * AuthAction performs authentication via different auth clients.
 * It supports [[OpenId]], [[OAuth1] and [[OAuth2]] client types.
 *
 * Usage:
 * ~~~
 * class SiteController extends Controller
 * {
 *     public function actions()
 *     {
 *         return [
 *             'auth' => [
 *                 'class' => 'yii\authclient\AuthAction',
 *                 'successCallback' => [$this, 'successCallback'],
 *             ],
 *         ]
 *     }
 *
 *     public function successCallback($client)
 *     {
 *         $atributes = $client->getUserAttributes();
 *         // user login or signup comes here
 *     }
 * }
 * ~~~
 *
 * Usually authentication via external services is performed inside the popup window.
 * This action handles the redirection and closing of popup window correctly.
 *
 * @see Collection
 * @see \yii\authclient\widgets\Choice
 *
 * @author Paul Klimov <klimov.paul@gmail.com>
 * @since 2.0
 */
class AuthAction extends Action
{
	/**
	 * @var string name of the auth client collection application component.
	 * It should point to [[Collection]] instance.
	 */
	public $clientCollection = 'authClientCollection';
	/**
	 * @var string name of the GET param, which is used to passed auth client id to this action.
	 * Note: watch for the naming, make sure you do not choose name used in some auth protocol.
	 */
	public $clientIdGetParamName = 'authclient';
	/**
	 * @var callable PHP callback, which should be triggered in case of successful authentication.
	 * This callback should accept [[ClientInterface]] instance as an argument.
	 * For example:
	 *
	 * ~~~
	 * public function onAuthSuccess($client)
	 * {
	 *     $atributes = $client->getUserAttributes();
	 *     // user login or signup comes here
	 * }
	 * ~~~
	 *
	 * If this callback returns [[Response]] instance, it will be used as action response,
	 * otherwise redirection to [[successUrl]] will be performed.
	 *
	 */
	public $successCallback;
	/**
	 * @var string the redirect url after successful authorization.
	 */
	private $_successUrl = '';
	/**
	 * @var string the redirect url after unsuccessful authorization (e.g. user canceled).
	 */
	private $_cancelUrl = '';
	/**
	 * @var string name or alias of the view file, which should be rendered in order to perform redirection.
	 * If not set default one will be used.
	 */
	public $redirectView;

	/**
	 * @param string $url successful URL.
	 */
	public function setSuccessUrl($url)
	{
		$this->_successUrl = $url;
	}

	/**
	 * @return string successful URL.
	 */
	public function getSuccessUrl()
	{
		if (empty($this->_successUrl)) {
			$this->_successUrl = $this->defaultSuccessUrl();
		}
		return $this->_successUrl;
	}

	/**
	 * @param string $url cancel URL.
	 */
	public function setCancelUrl($url)
	{
		$this->_cancelUrl = $url;
	}

	/**
	 * @return string cancel URL.
	 */
	public function getCancelUrl()
	{
		if (empty($this->_cancelUrl)) {
			$this->_cancelUrl = $this->defaultCancelUrl();
		}
		return $this->_cancelUrl;
	}

	/**
	 * Creates default {@link successUrl} value.
	 * @return string success URL value.
	 */
	protected function defaultSuccessUrl()
	{
		return Yii::$app->getUser()->getReturnUrl();
	}

	/**
	 * Creates default {@link cancelUrl} value.
	 * @return string cancel URL value.
	 */
	protected function defaultCancelUrl()
	{
		return Yii::$app->getRequest()->getAbsoluteUrl();
	}

	/**
	 * Runs the action.
	 */
	public function run()
	{
		if (!empty($_GET[$this->clientIdGetParamName])) {
			$clientId = $_GET[$this->clientIdGetParamName];
			/** @var \yii\authclient\Collection $collection */
			$collection = Yii::$app->getComponent($this->clientCollection);
			if (!$collection->hasClient($clientId)) {
				throw new NotFoundHttpException("Unknown auth client '{$clientId}'");
			}
			$client = $collection->getClient($clientId);
			return $this->auth($client);
		} else {
			throw new NotFoundHttpException();
		}
	}

	/**
	 * @param mixed $client auth client instance.
	 * @return Response response instance.
	 * @throws \yii\base\NotSupportedException on invalid client.
	 */
	protected function auth($client)
	{
		if ($client instanceof OpenId) {
			return $this->authOpenId($client);
		} elseif ($client instanceof OAuth2) {
			return $this->authOAuth2($client);
		} elseif ($client instanceof OAuth1) {
			return $this->authOAuth1($client);
		} else {
			throw new NotSupportedException('Provider "' . get_class($client) . '" is not supported.');
		}
	}

	/**
	 * This method is invoked in case of successful authentication via auth client.
	 * @param ClientInterface $client auth client instance.
	 * @throws InvalidConfigException on invalid success callback.
	 * @return Response response instance.
	 */
	protected function authSuccess($client)
	{
		if (!is_callable($this->successCallback)) {
			throw new InvalidConfigException('"' . get_class($this) . '::successCallback" should be a valid callback.');
		}
		$response = call_user_func($this->successCallback, $client);
		if ($response instanceof Response) {
			return $response;
		}
		return $this->redirectSuccess();
	}

	/**
	 * Redirect to the given URL or simply close the popup window.
	 * @param mixed $url URL to redirect, could be a string or array config to generate a valid URL.
	 * @param boolean $enforceRedirect indicates if redirect should be performed even in case of popup window.
	 * @return \yii\web\Response response instance.
	 */
	public function redirect($url, $enforceRedirect = true)
	{
		$viewFile = $this->redirectView;
		if ($viewFile === null) {
			$viewFile = __DIR__ . DIRECTORY_SEPARATOR . 'views' . DIRECTORY_SEPARATOR . 'redirect.php';
		} else {
			$viewFile = Yii::getAlias($viewFile);
		}
		$viewData = [
			'url' => $url,
			'enforceRedirect' => $enforceRedirect,
		];
		$response = Yii::$app->getResponse();
		$response->content = Yii::$app->getView()->renderFile($viewFile, $viewData);
		return $response;
	}

	/**
	 * Redirect to the URL. If URL is null, {@link successUrl} will be used.
	 * @param string $url URL to redirect.
	 * @return \yii\web\Response response instance.
	 */
	public function redirectSuccess($url = null)
	{
		if ($url === null) {
			$url = $this->getSuccessUrl();
		}
		return $this->redirect($url);
	}

	/**
	 * Redirect to the {@link cancelUrl} or simply close the popup window.
	 * @param string $url URL to redirect.
	 * @return \yii\web\Response response instance.
	 */
	public function redirectCancel($url = null)
	{
		if ($url === null) {
			$url = $this->getCancelUrl();
		}
		return $this->redirect($url, false);
	}

	/**
	 * Performs OpenID auth flow.
	 * @param OpenId $client auth client instance.
	 * @return Response action response.
	 * @throws Exception on failure.
	 * @throws HttpException on failure.
	 */
	protected function authOpenId($client)
	{
		if (!empty($_REQUEST['openid_mode'])) {
			switch ($_REQUEST['openid_mode']) {
				case 'id_res':
					if ($client->validate()) {
						return $this->authSuccess($client);
					} else {
						throw new HttpException(400, 'Unable to complete the authentication because the required data was not received.');
					}
					break;
				case 'cancel':
					$this->redirectCancel();
					break;
				default:
					throw new HttpException(400);
					break;
			}
		} else {
			$url = $client->buildAuthUrl();
			return Yii::$app->getResponse()->redirect($url);
		}
		return $this->redirectCancel();
	}

	/**
	 * Performs OAuth1 auth flow.
	 * @param OAuth1 $client auth client instance.
	 * @return Response action response.
	 */
	protected function authOAuth1($client)
	{
		// user denied error
		if (isset($_GET['denied'])) {
			return $this->redirectCancel();
		}

		if (isset($_REQUEST['oauth_token'])) {
			$oauthToken = $_REQUEST['oauth_token'];
		}

		if (!isset($oauthToken)) {
			// Get request token.
			$requestToken = $client->fetchRequestToken();
			// Get authorization URL.
			$url = $client->buildAuthUrl($requestToken);
			// Redirect to authorization URL.
			return Yii::$app->getResponse()->redirect($url);
		} else {
			// Upgrade to access token.
			$accessToken = $client->fetchAccessToken();
			return $this->authSuccess($client);
		}
	}

	/**
	 * Performs OAuth2 auth flow.
	 * @param OAuth2 $client auth client instance.
	 * @return Response action response.
	 * @throws \yii\base\Exception on failure.
	 */
	protected function authOAuth2($client)
	{
		if (isset($_GET['error'])) {
			if ($_GET['error'] == 'access_denied') {
				// user denied error
				return $this->redirectCancel();
			} else {
				// request error
				if (isset($_GET['error_description'])) {
					$errorMessage = $_GET['error_description'];
				} elseif (isset($_GET['error_message'])) {
					$errorMessage = $_GET['error_message'];
				} else {
					$errorMessage = http_build_query($_GET);
				}
				throw new Exception('Auth error: ' . $errorMessage);
			}
		}

		// Get the access_token and save them to the session.
		if (isset($_GET['code'])) {
			$code = $_GET['code'];
			$token = $client->fetchAccessToken($code);
			if (!empty($token)) {
				return $this->authSuccess($client);
			} else {
				return $this->redirectCancel();
			}
		} else {
			$url = $client->buildAuthUrl();
			return Yii::$app->getResponse()->redirect($url);
		}
	}
}