<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\UX\TwigComponent;

/**
 * @author Ryan Weaver <ryan@symfonycasts.com>
 *
 * @internal
 */
class ComponentStack implements \IteratorAggregate
{
    /**
     * @var MountedComponent[]
     */
    private array $components = [];

    public function push(MountedComponent $components)
    {
        $this->components[] = $components;
    }

    public function pop(): ?MountedComponent
    {
        if (!$this->components) {
            return null;
        }

        return array_pop($this->components);
    }

    /**
     * The current component being rendered.
     */
    public function getCurrentComponent(): ?MountedComponent
    {
        return end($this->components) ?: null;
    }

    /**
     * The parent of the current component being rendered.
     */
    public function getParentComponent(): ?MountedComponent
    {
        $components = $this->components;
        array_pop($components);

        return array_pop($components);
    }

    public function hasParentComponent(): bool
    {
        return (bool) $this->getParentComponent();
    }

    /**
     * @return MountedComponent[]|\ArrayIterator
     */
    public function getIterator(): \Traversable
    {
        return new \ArrayIterator(array_reverse($this->components));
    }
}