<?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-misspell
* @version 1.0.38
* @copyright Copyright (C) 2020 Mirasvit (https://mirasvit.com/)
*/


namespace Mirasvit\Misspell\Helper;

use Magento\Framework\App\Helper\AbstractHelper;

class Text extends AbstractHelper
{
const ICONV_CHARSET = 'UTF-8';
/**
* Minimum allowed fulltext gram
*
* @return int
*/
public function getGram()
{
return 4;
}

/**
* Clean string (remove not utf chars)
*
* @param string $string
* @return string
*/
public function cleanString($string)
{
$string = $this->toUTF8($string);

$string = preg_replace('/[^\p{L}0-9\-]/u', ' ', $string);
$string = trim(preg_replace('/\s+/', ' ', $string));

return $string;
}

/**
* Split string to words
*
* @param string $string
* @return array
*/
public function splitWords($string)
{
$split = preg_split('#\s#siu', $string, null, PREG_SPLIT_NO_EMPTY);

$result = [];

foreach ($split as $word) {
$result[$word] = $word;
}

return array_values($result);
}

/**
* Split string to trigrams
*
* @param string $keyword
* @return string
*/
public function getTrigram($keyword)
{
$keyword = $this->toUTF8($keyword);

$trigram = [];

$len = mb_strlen($keyword);

for ($i = 1; $i < $len + $this->getGram(); $i++) {
$trig = '';
for ($j = $i - $this->getGram(); $j < $i; $j++) {
if ($j >= 0 && $j < $len) {
$trig .= mb_substr($keyword, $j, 1);
} else {
$trig .= '_';
}
}

$trigram[] = $trig;
}

return implode(' ', $trigram);
}

/**
* String length
*
* @param string $string
* @return int
*/
public function strlen($string)
{
return mb_strlen($this->toUTF8($string));
}

/**
* Sub string
*
* @param string $string
* @param int $offset
* @param null $length
* @return string
*/
public function substr($string, $offset, $length = null)
{
$string = $this->cleanString($string);
if (is_null($length)) {
$length = $this->strlen($string) - $offset;
}
return iconv_substr($string, $offset, $length, self::ICONV_CHARSET);
}

/**
* Convert string to lower registry
*
* @param string $string
* @return string
*/
public function strtolower($string)
{
return mb_strtolower($string);
}

/**
* Convert string to UTF8
*
* @param string $string
* @return string
*/
public function toUTF8($string)
{
$newString = false;
try {
$newString = iconv("UTF-8", "UTF-8//IGNORE", $string);
} catch (\LogicException $e) {
$e->getMessage();
}

if ($newString === false) {
return $string;
}

return $newString;
}

/**
* Highlight difference between 2 string using html tag
*
* @param string $new
* @param string $old
* @param string $tag
* @return string
*/
public function htmlDiff($new, $old, $tag)
{
$ret = '';
$diff = $this->diff(explode(' ', $old), explode(' ', $new));
foreach ($diff as $k) {
if (is_array($k)) {
$ret .= !empty($k['i']) ? "<" . $tag . ">" . implode(' ', $k['i']) . "</" . $tag . "> " : '';
} else {
$ret .= $k . ' ';
}
}

return $ret;
}

/**
* Find difference
*
* @param array<string> $old
* @param array<string> $new
* @return array
*/
protected function diff($old, $new)
{
$maxLen = $oldMax = $newMax = 0;
foreach ($old as $oldIndex => $oldChar) {
$keys = array_keys($new, $oldChar);
foreach ($keys as $newIndex) {
$matrix[$oldIndex][$newIndex] = isset($matrix[$oldIndex - 1][$newIndex - 1]) ?
$matrix[$oldIndex - 1][$newIndex - 1] + 1 : 1;
if ($matrix[$oldIndex][$newIndex] > $maxLen) {
$maxLen = $matrix[$oldIndex][$newIndex];
$oldMax = $oldIndex + 1 - $maxLen;
$newMax = $newIndex + 1 - $maxLen;
}
}
}

if ($maxLen == 0) {
return [['d' => $old, 'i' => $new]];
}

return array_merge(
$this->diff(array_slice($old, 0, $oldMax), array_slice($new, 0, $newMax)),
array_slice($new, $newMax, $maxLen),
$this->diff(array_slice($old, $oldMax + $maxLen), array_slice($new, $newMax + $maxLen))
);
}
}