<?php
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
namespace Magento\Framework\View\Layout\Data;

use Magento\Framework\Data\Structure as DataStructure;
use Magento\Framework\App\State;

/**
* An associative data structure, that features "nested set" parent-child relations
*
* @api
* @since 100.0.2
*/
class Structure extends DataStructure
{
/**
* Name increment counter
*
* @var array
*/
protected $_nameIncrement = [];

/**
* @var \Psr\Log\LoggerInterface
*/
protected $logger;

/**
* @var State
*/
protected $state;

/**
* Constructor
*
* @param \Psr\Log\LoggerInterface $logger
* @param State $state
* @param array $elements
*/
public function __construct(
\Psr\Log\LoggerInterface $logger,
State $state,
array $elements = null
) {
$this->logger = $logger;
$this->state = $state;
parent::__construct($elements);
}

/**
* Register an element in structure
*
* Will assign an "anonymous" name to the element, if provided with an empty name
*
* @param string $name
* @param string $type
* @param string $class
* @return string
*/
public function createStructuralElement($name, $type, $class)
{
if (empty($name)) {
$name = $this->_generateAnonymousName($class);
}
$this->createElement($name, ['type' => $type]);
return $name;
}

/**
* Generate anonymous element name for structure
*
* @param string $class
* @return string
*/
protected function _generateAnonymousName($class)
{
$position = strpos($class, '\\Block\\');
$key = $position !== false ? substr($class, $position + 7) : $class;
$key = strtolower(trim($key, '_'));

if (!isset($this->_nameIncrement[$key])) {
$this->_nameIncrement[$key] = 0;
}

do {
$name = $key . '_' . $this->_nameIncrement[$key]++;
} while ($this->hasElement($name));

return $name;
}

/**
* Reorder a child of a specified element
*
* If $offsetOrSibling is null, it will put the element to the end
* If $offsetOrSibling is numeric (integer) value, it will put the element after/before specified position
* Otherwise -- after/before specified sibling
*
* @param string $parentName
* @param string $childName
* @param string|int|null $offsetOrSibling
* @param bool $after
* @return void
*/
public function reorderChildElement($parentName, $childName, $offsetOrSibling, $after = true)
{
if (is_numeric($offsetOrSibling)) {
$offset = (int)abs($offsetOrSibling) * ($after ? 1 : -1);
$this->reorderChild($parentName, $childName, $offset);
} elseif (null === $offsetOrSibling) {
$this->reorderChild($parentName, $childName, null);
} else {
$children = array_keys($this->getChildren($parentName));
if ($this->getChildId($parentName, $offsetOrSibling) !== false) {
$offsetOrSibling = $this->getChildId($parentName, $offsetOrSibling);
}
$sibling = $this->_filterSearchMinus($offsetOrSibling, $children, $after);
if ($childName !== $sibling) {
$siblingParentName = $this->getParentId($sibling);
if ($parentName !== $siblingParentName) {
if ($this->state->getMode() === State::MODE_DEVELOPER) {
$this->logger->info(
"Broken reference: the '{$childName}' tries to reorder itself towards '{$sibling}', but " .
"their parents are different: '{$parentName}' and '{$siblingParentName}' respectively."
);
}
return;
}
$this->reorderToSibling($parentName, $childName, $sibling, $after ? 1 : -1);
}
}
}

/**
* Search for an array element using needle, but needle may be '-', which means "first" or "last" element
*
* Returns first or last element in the haystack, or the $needle argument
*
* @param string $needle
* @param array $haystack
* @param bool $isLast
* @return string
*/
protected function _filterSearchMinus($needle, array $haystack, $isLast)
{
if ('-' === $needle) {
if ($isLast) {
return array_pop($haystack);
}
return array_shift($haystack);
}
return $needle;
}
}