class.ilLTIConsumerLaunch.php

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<?php

declare(strict_types=1);

use ceLTIc\LTI\OAuth\OAuthConsumer;
use ceLTIc\LTI\OAuth\OAuthRequest;
use ceLTIc\LTI\OAuth\OAuthSignatureMethod_HMAC_SHA1;

class ilLTIConsumerLaunch
{
    private ?array $context = null;
    protected int $ref_id;

    public function __construct(int $a_ref_id)
    {
        $this->ref_id = $a_ref_id;
    }

    public function getContext(?array $a_valid_types = array('crs', 'grp', 'cat', 'root')): ?array
    {
        global $DIC; /* @var \ILIAS\DI\Container $DIC */
        $tree = $DIC->repositoryTree();

        if (!isset($this->context)) {
            $this->context = array();

            // check fromm inner to outer
            $path = array_reverse($tree->getPathFull($this->ref_id));
            foreach ($path as $row) {
                if (in_array($row['type'], $a_valid_types)) {
                    // take an existing inner context outside a course
                    if (in_array($row['type'], array('cat', 'root')) && !empty($this->context)) {
                        break;
                    }

                    $this->context['id'] = $row['child'];
                    $this->context['title'] = $row['title'];
                    $this->context['type'] = $row['type'];

                    // don't break to get the most outer course or group
                }
            }
        }
        return $this->context;
    }




    public static function getLTIContextType(string $a_type): string
    {
        switch ($a_type) {
            case "crs":
                return "http://purl.imsglobal.org/vocab/lis/v2/course#CourseOffering";
            case "grp":
                return "http://purl.imsglobal.org/vocab/lis/v2/course#Group";
            case "root":
                return "http://purl.imsglobal.org/vocab/lis/v2/course#CourseOffering";
            case "cat":
            default:
                return "http://purl.imsglobal.org/vocab/lis/v2/course#CourseOffering";
        }
    }


    public static function signOAuth(array $a_params): array
    {
        switch ($a_params['sign_method']) {
            case "HMAC_SHA1":
                $method = new OAuthSignatureMethod_HMAC_SHA1();
                break;
            default:
                throw new Exception("Unknown signature method: " . $a_params['sign_method']);
        }

        $consumer = new OAuthConsumer($a_params["key"], $a_params["secret"], $a_params["callback"]);
        $request = OAuthRequest::from_consumer_and_token($consumer, $a_params["token"], $a_params["http_method"], $a_params["url"], $a_params["data"]);
        $request->sign_request($method, $consumer, $a_params["token"]);

        // Pass this back up "out of band" for debugging
        //        self::$last_oauth_base_string = $request->get_signature_base_string();
        // die(self::$last_oauth_base_string);

        return $request->get_parameters();
    }
}