Removed support to Facebook.

<?php

/*

 * This file is part of rap

 * Copyright (C) 2021 Istituto Nazionale di Astrofisica

 * SPDX-License-Identifier: GPL-3.0-or-later

 */

namespace RAP;

class FacebookLogin extends LoginHandler {

    public function __construct(Locator $locator) {

        parent::__construct($locator);

    }

    public function login(): string {

        // Retrieve Facebook configuration

        $Facebook = $this->locator->config->authenticationMethods->Facebook;

        $fb = new \Facebook\Facebook([

            'app_id' => $Facebook->id,

            'app_secret' => $Facebook->secret,

            'default_graph_version' => $Facebook->version,

        ]);

        $helper = $fb->getRedirectLoginHelper();

        $permissions = ['email']; // Optional permissions: we need user email

        $loginUrl = $helper->getLoginUrl($this->locator->getBasePath() . $Facebook->callback, $permissions);

        return $loginUrl;

    }

    public function retrieveToken(): string {

        // Retrieve Facebook configuration

        $Facebook = $this->locator->config->authenticationMethods->Facebook;

        $fb = new \Facebook\Facebook([

            'app_id' => $Facebook->id,

            'app_secret' => $Facebook->secret,

            'default_graph_version' => $Facebook->version,

        ]);

        $helper = $fb->getRedirectLoginHelper();

        if (isset($_GET['state'])) {

            $helper->getPersistentDataHandler()->set('state', $_GET['state']);

        }

        // obtaining current URL without query string

        $accessToken = $helper->getAccessToken($this->locator->getBasePath() . $Facebook->callback);

        if (!isset($accessToken)) {

            if ($helper->getError()) {

                $errorMessage = "Error: " . $helper->getError() . "<br>";

                $errorMessage = $errorMessage . "Error Code: " . $helper->getErrorCode() . "<br>";

                $errorMessage = $errorMessage . "Error Reason: " . $helper->getErrorReason() . "<br>";

                $errorMessage = $errorMessage . "Error Description: " . $helper->getErrorDescription();

                throw new ServerErrorException($errorMessage);

            } else {

                throw new BadRequestException("Unable to obtain access token");

            }

        }

        // Returns a `Facebook\FacebookResponse` object

        $response = $fb->get('/me?fields=id,first_name,last_name,email', $accessToken);

        $_SESSION['fb_access_token'] = (string) $accessToken;

        $fbUser = $response->getGraphUser();

        $identity = new Identity(Identity::FACEBOOK);

        $identity->typedId = $fbUser["id"];

        $identity->email = $fbUser["email"];

        $identity->name = $fbUser["first_name"];

        $identity->surname = $fbUser["last_name"];

        return $this->onIdentityDataReceived($identity);

    }

}