Middleware Args

middleware_args.php

<?php
/**
 *
 */

namespace Mvc5\Service;

use Mvc5\Arg;
use Mvc5\Signal;

trait Middleware
{
    /**
     * @var Service
     */
    protected $service;

    /**
     * @var array|\Iterator
     */
    protected $config;

    /**
     * @param Service $service
     * @param array|\Iterator $config
     */
    function __construct(Service $service, $config = [])
    {
        $this->service = $service;
        $this->config = $config;
    }

    /**
     * @param array $argv
     * @return array
     */
    protected function args(array $argv)
    {
        return is_string(key($argv)) ? [Arg::NEXT => $this->delegate()] + $argv : array_merge($argv, [$this->delegate()]);
    }

    /**
     * @param $middleware
     * @param array $args
     * @return mixed
     */
    protected function call($middleware, $args)
    {
        return $middleware ? $this->service->call($middleware, $this->args(Signal::args($args))) : $this->end(Signal::args($args));
    }

    /**
     * @return mixed
     */
    protected function delegate()
    {
        return function(...$argv) {
            return $this->call($this->next(), $argv);
        };
    }

    /**
     * @param array $args
     * @return mixed|null
     */
    protected function end(array $args)
    {
        return $args ? end($args) : null;
    }

    /**
     * @return mixed
     */
    protected function next()
    {
        if ($this->config instanceof \Iterator) {
            $this->config->next();
            return $this->config->current();
        }

        return next($this->config);
    }

    /**
     * @return mixed
     */
    protected function rewind()
    {
        if ($this->config instanceof \Iterator) {
            $this->config->rewind();
            return $this->config->current();
        }

        return reset($this->config);
    }

    /**
     * @param array ...$argv
     * @return mixed
     */
    function __invoke(...$argv)
    {
        return $this->call($this->rewind(), $argv);
    }
}