<?php
/**
* Copyright © Magento, Inc. All rights reserved.
* See COPYING.txt for license details.
*/
declare(strict_types=1);

namespace Magento\Framework\GraphQl\Query;

use GraphQL\Validator\DocumentValidator;
use GraphQL\Validator\Rules\DisableIntrospection;
use GraphQL\Validator\Rules\QueryDepth;
use GraphQL\Validator\Rules\QueryComplexity;

/**
* QueryComplexityLimiter
*
* Sets limits for query complexity. A single GraphQL query can potentially
* generate thousands of database operations so, the very complex queries
* should be filtered and rejected.
*
* https://github.com/webonyx/graphql-php/blob/master/docs/security.md#query-complexity-analysis
*/
class QueryComplexityLimiter
{
/**
* @var int
*/
private $queryDepth;

/**
* @var int
*/
private $queryComplexity;

/**
* @var IntrospectionConfiguration
*/
private $introspectionConfig;

/**
* @param int $queryDepth
* @param int $queryComplexity
* @param IntrospectionConfiguration $introspectionConfig
*/
public function __construct(
int $queryDepth,
int $queryComplexity,
IntrospectionConfiguration $introspectionConfig
) {
$this->queryDepth = $queryDepth;
$this->queryComplexity = $queryComplexity;
$this->introspectionConfig = $introspectionConfig;
}

/**
* Sets limits for query complexity
*
* @return void
*/
public function execute(): void
{
DocumentValidator::addRule(new QueryComplexity($this->queryComplexity));
DocumentValidator::addRule(
new DisableIntrospection((int) $this->introspectionConfig->isIntrospectionDisabled())
);
DocumentValidator::addRule(new QueryDepth($this->queryDepth));
}
}