<?php
/**
* Mirasvit
*
* This source file is subject to the Mirasvit Software License, which is available at https://mirasvit.com/license/.
* Do not edit or add to this file if you wish to upgrade the to newer versions in the future.
* If you wish to customize this module for your needs.
* Please refer to http://www.magentocommerce.com for more information.
*
* @category Mirasvit
* @package mirasvit/module-search-ultimate
* @version 2.3.2
* @copyright Copyright (C) 2024 Mirasvit (https://mirasvit.com/)
*/



declare(strict_types=1);

namespace Mirasvit\Misspell\Adapter\Elasticsearch;

use Mirasvit\Misspell\Api\Data\SuggestInterface;
use Magento\Elasticsearch\SearchAdapter\ConnectionManager;
use Magento\Elasticsearch\SearchAdapter\SearchIndexNameResolver;
use Magento\Store\Model\StoreManagerInterface;

class Suggester implements SuggestInterface
{
private $connectionManager;

private $searchIndexNameResolver;

private $storeManager;

private $indexName = null;

public function __construct(
ConnectionManager $connectionManager,
SearchIndexNameResolver $searchIndexNameResolver,
StoreManagerInterface $storeManager
) {
$this->connectionManager = $connectionManager;
$this->searchIndexNameResolver = $searchIndexNameResolver;
$this->storeManager = $storeManager;
}

public function suggest(string $query): ?string
{
$query = preg_split('/[\s]+/', $query);
/** @var \Magento\Elasticsearch7\Model\Client\Elasticsearch $connection */
$connection = $this->connectionManager->getConnection();

if (!$connection->indexExists($this->getIndexName())) {
return null;
}

$response = [];

if (!is_array($query)) {
$query = [$query];
}

foreach ($query as $term) {
$result = $connection->query($this->prepareTermSuggestQuery($term));

$processedResponse = $this->processResponse($result);

if (empty($processedResponse)) {
$result = $connection->query($this->preparePhraseSuggestQuery($term));
$processedResponse = $this->processResponse($result);
}

$response[] = $processedResponse;
}

$response = array_filter($response);
$response = array_unique($response);

if (empty($response)) {
return null;
}

return implode(' ', $response);
}

private function prepareTermSuggestQuery(string $query): array
{
return [
'index' => $this->getIndexName(),
'body' => [
'suggest' => [
'suggestion' => [
'text' => $query,
'term' => [
'field' => 'keyword',
'size' => 1,
'prefix_length' => 0,
],
],
],
],
];
}

private function preparePhraseSuggestQuery(string $query): array
{
return [
'index' => $this->getIndexName(),
'body' => [
'suggest' => [
'text' => $query,
'suggestion' => [
'phrase' => [
'field' => 'keyword.trigram',
'size' => 1,
'gram_size' => 3,
'max_errors' => 100,
'direct_generator' => [
[
'field' => 'keyword.trigram',
'suggest_mode' => 'always',
],
],
],
],
],
],
];
}

private function getIndexName(): string
{
if ($this->indexName === null) {
$this->indexName = $this->searchIndexNameResolver->getIndexName(
$this->storeManager->getStore()->getId(),
'mst_misspell_index'
);
}

return $this->indexName;
}

private function processResponse(array $response): ?string
{
$result = null;
if (isset($response['suggest']['suggestion'][0]['options'][0]['text'])) {
$result = $response['suggest']['suggestion'][0]['options'][0]['text'];
} else if (isset($response['suggest']['suggestion'][0]['text'])) {
$result = $response['suggest']['suggestion'][0]['text'];
}

return $result;
}
}