cfnpp/app/Util/GraphNode.php

<?php

declare(strict_types=1);

namespace App\Util;

class GraphNode
{
	protected $parent;

	protected $value;

	protected $children;

	public function __construct($value = null)
	{
		$this->value = $value;
		$this->children = [];
	}

	public function __invoke()
	{
		return $this->value;
	}

	public function setValue($value): void
	{
		$this->value = $value;
	}

	public function getValue()
	{
		return $this->value;
	}

	public function setParent(GraphNode $node): void
	{
		$this->parent = $node;
	}

	public function hasParent(): bool
	{
		return isset($this->parent);
	}

	public function getParent(): GraphNode
	{
		return $this->parent;
	}

	public function countChildren(): int
	{
		return sizeof($this->children);
	}

	public function hasChildren(): bool
	{
		return sizeof($this->children) > 0;
	}

	public function getChildren(): array
	{
		return $this->children;
	}

	public function appendChild(GraphNode $child): void
	{
		$this->children[] = $child;
		$child->setParent($this);
	}

	public function replaceChild(GraphNode $original, GraphNode $new): void
	{
		for ($i = 0; $i < sizeof($this->children); $i++)
		{
			if ($this->children[$i] === $original)
			{
				$this->children[$i] = $new;
				$new->setParent($this);
				return;
			}
		}
	}

	public function clearChildren(): void
	{
		$this->children = [];
	}

	public function add($value): GraphNode
	{
		$this->children[] = new GraphNode($value);
		end($this->children)->setParent($this);
		return end($this->children);
	}

	public function walk(callable $callback)
	{
		static::walkNodes([$this], $callback);
	}

	protected static function walkNodes(array $nodes, callable $callback)
	{
		foreach ($nodes as $node)
		{
			if ($node->hasChildren())
			{
				static::walkNodes($node->getChildren(), $callback);
			}

			$callback($node);
		}
	}
}