<?php
/*
Copyright 2017 Ziadin Givan

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

https://github.com/givanz/VvvebJs
*/

require_once('../../../config.php');

require_login();
require_capability('moodle/site:config', context_system::instance());

$chave = required_param('chave', PARAM_TEXT);
$lang = required_param('lang', PARAM_TEXT);

define('MAX_FILE_LIMIT', 1024 * 1024 * 2);//2 Megabytes max html file size
define('ALLOW_PHP', false);//check if saved html contains php tag and don't save if not allowed
define('ALLOWED_OEMBED_DOMAINS', [
    'https://www.youtube.com/',
    'https://www.vimeo.com/',
    'https://www.x.com/',
    'https://x.com/',
    'https://publish.twitter.com/',
    'https://www.twitter.com/',
    'https://www.reddit.com/',
]);//load urls only from allowed websites for oembed

function sanitizeFileName($file, $allowedExtension = 'html') {
    $basename = basename($file);
    $disallow = ['.htaccess', 'passwd'];
    if (in_array($basename, $disallow)) {
        showError('Filename not allowed!');
        return '';
    }

    //sanitize, remove double dot .. and remove get parameters if any
    $file = preg_replace('@\?.*$@', '', preg_replace('@\.{2,}@', '', preg_replace('@[^\/\\a-zA-Z0-9\-\._]@', '', $file)));

    if ($file) {
        $file = __DIR__ . DIRECTORY_SEPARATOR . $file;
    } else {
        return '';
    }

    //allow only .html extension
    if ($allowedExtension) {
        $file = preg_replace('/\.[^.]+$/', '', $file) . ".$allowedExtension";
    }
    return $file;
}

function showError($error) {
    header($_SERVER['SERVER_PROTOCOL'] . ' 404', true, 500);
    die($error);
}

function validOembedUrl($url) {
    foreach (ALLOWED_OEMBED_DOMAINS as $domain) {
        if (strpos($url, $domain) === 0) {
            return true;
        }
    }

    return false;
}

$html = '';
$file = '';
$action = '';

if (isset($_POST['startTemplateUrl']) && !empty($_POST['startTemplateUrl'])) {
    $startTemplateUrl = sanitizeFileName($_POST['startTemplateUrl']);
    $html = '';
    if ($startTemplateUrl) {
        $html = file_get_contents($startTemplateUrl);
    }
} else if (isset($_POST['html'])) {
    $html = substr($_POST['html'], 0, MAX_FILE_LIMIT);
    if (!ALLOW_PHP) {
        //if (strpos($html, '<?php') !== false) {
        if (preg_match('@<\?php|<\? |<\?=|<\s*script\s*language\s*=\s*"\s*php\s*"\s*>@', $html)) {
            showError('PHP not allowed!');
        }
    }
}
$html = preg_replace('/<.*?vvveb-remove.*?>/si', '', $html);

if (isset($_POST['file'])) {
    $file = sanitizeFileName($_POST['file']);
}

if (isset($_GET['action'])) {
    $action = htmlspecialchars(strip_tags($_GET['action']));
}

\cache::make("theme_boost_magnific", "layout_cache")->purge();
\cache::make("theme_boost_magnific", "css_cache")->purge();
\cache::make("theme_boost_magnific", "logo_cache")->purge();

if ($action) {
    //file manager actions, delete and rename
    switch ($action) {
        case 'delete':
            $return =[
                "success" => 1,
                "message" => "Deleted successfully",
            ];

            $json = file_get_contents('php://input');
            $data = json_decode($json);
            preg_match('/pluginfile.php\/(\d+)\/theme_boost_magnific\/(editor_\w+)\/(\d+)\/(.*)/', $data->file, $filePartes);

            if (isset($filePartes[4])) {
                $contextid = $filePartes[1];
                $component = "theme_boost_magnific";
                $filearea = $filePartes[2];
                $itemid = $filePartes[3];
                $filename = $filePartes[4];

                $return['$contextid'] = $contextid;
                $return['$component'] = $component;
                $return['$filearea'] = $filearea;
                $return['$itemid'] = $itemid;

                $fs = get_file_storage();
                $fs->delete_area_files($contextid, $component, $filearea, $itemid);
            }

            header('Content-Type: application/json');
            echo json_encode($return);
            break;
        case 'save':
            set_config("{$chave}_htmleditor_{$lang}", $html, "theme_boost_magnific");
            echo json_encode([
                "success" => 1,
                "message" => "Saved successfully",
            ]);
            break;
        case 'oembedProxy':
            $url = $_GET['url'] ?? '';
            if (validOembedUrl($url)) {
                $options = array(
                    'http' => array(
                        'method' => "GET",
                        'header' => 'User-Agent: ' . $_SERVER['HTTP_USER_AGENT'] . "\r\n"
                    )
                );
                $context = stream_context_create($options);
                header('Content-Type: application/json');
                echo file_get_contents($url, false, $context);
            } else {
                showError('Invalid url!');
            }
            break;
        default:
            showError("Invalid action '$action'!");
    }
} else {
    echo json_encode([
        "success" => 0,
        "message" => "Ops...",
    ]);
}
