wikimedia/mediawiki-extensions-Wikibase

<?php declare( strict_types=1 );

namespace Wikibase\Repo\RestApi\RouteHandlers\Middleware;

use MediaWiki\Rest\Handler;
use MediaWiki\Rest\Response;

/**
 * @license GPL-2.0-or-later
 */
class PreconditionMiddleware implements Middleware {

    private RequestPreconditionCheck $preconditionCheck;

    public function __construct( RequestPreconditionCheck $preconditionCheck ) {
        $this->preconditionCheck = $preconditionCheck;
    }

    public function run( Handler $routeHandler, callable $runNext ): Response {
        $preconditionCheckResult = $this->preconditionCheck->checkPreconditions( $routeHandler->getRequest() );
        switch ( $preconditionCheckResult->getStatusCode() ) {
            case 304:
                $notModifiedResponse = $routeHandler->getResponseFactory()->createNotModified();
                $notModifiedResponse->setHeader( 'ETag', '"' . $preconditionCheckResult->getRevisionId() . '"' );

                return $notModifiedResponse;
            case 412:
                $response = $routeHandler->getResponseFactory()->createNoContent();
                $response->setStatus( 412 );

                return $response;
            default:
                return $runNext();
        }
    }
}