src/Middleware/MiddlewarePipeline.php


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<?php

declare(strict_types=1);

namespace BrettParson\MiniRoute\Middleware;

use BrettParson\MiniRoute\Http\RequestInterface;
use BrettParson\MiniRoute\Http\ResponseInterface;

final class MiddlewarePipeline
{
    /**
     * Wrap a core handler with an ordered list of middleware instances.
     *
     * The first middleware in $middleware becomes the outermost layer, so a
     * request flows through it first and its response post-processing runs
     * last.
     *
     * @param list<MiddlewareInterface> $middleware
     * @param callable(RequestInterface): ResponseInterface $core
     * @return callable(RequestInterface): ResponseInterface
     */
    public static function compose(array $middleware, callable $core): callable
    {
        foreach (array_reverse($middleware) as $middlewareInstance) {
            $next = $core;

            $core = static function (RequestInterface $request) use ($middlewareInstance, $next): ResponseInterface {
                return $middlewareInstance->handle($request, $next);
            };
        }

        return $core;
    }
}