<?php declare(strict_types=1);
/*
 * This file is part of sebastian/diff.
 *
 * (c) Sebastian Bergmann <sebastian@phpunit.de>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace SebastianBergmann\Diff;

use const PHP_INT_SIZE;
use const PREG_SPLIT_DELIM_CAPTURE;
use const PREG_SPLIT_NO_EMPTY;
use function array_shift;
use function array_unshift;
use function array_values;
use function count;
use function current;
use function end;
use function is_string;
use function key;
use function min;
use function preg_split;
use function prev;
use function reset;
use function str_ends_with;
use function substr;
use SebastianBergmann\Diff\Output\DiffOutputBuilderInterface;

final class Differ
{
    public const OLD                     = 0;
    public const ADDED                   = 1;
    public const REMOVED                 = 2;
    public const DIFF_LINE_END_WARNING   = 3;
    public const NO_LINE_END_EOF_WARNING = 4;
    private DiffOutputBuilderInterface $outputBuilder;

    public function __construct(DiffOutputBuilderInterface $outputBuilder)
    {
        $this->outputBuilder = $outputBuilder;
    }

    public function diff(array|string $from, array|string $to, ?LongestCommonSubsequenceCalculator $lcs = null): string
    {
        $diff = $this->diffToArray($from, $to, $lcs);

        return $this->outputBuilder->getDiff($diff);
    }

    public function diffToArray(array|string $from, array|string $to, ?LongestCommonSubsequenceCalculator $lcs = null): array
    {
        if (is_string($from)) {
            $from = $this->splitStringByLines($from);
        }

        if (is_string($to)) {
            $to = $this->splitStringByLines($to);
        }

        [$from, $to, $start, $end] = self::getArrayDiffParted($from, $to);

        if ($lcs === null) {
            $lcs = $this->selectLcsImplementation($from, $to);
        }

        $common = $lcs->calculate(array_values($from), array_values($to));
        $diff   = [];

        foreach ($start as $token) {
            $diff[] = [$token, self::OLD];
        }

        reset($from);
        reset($to);

        foreach ($common as $token) {
            while (($fromToken = reset($from)) !== $token) {
                $diff[] = [array_shift($from), self::REMOVED];
            }

            while (($toToken = reset($to)) !== $token) {
                $diff[] = [array_shift($to), self::ADDED];
            }

            $diff[] = [$token, self::OLD];

            array_shift($from);
            array_shift($to);
        }

        while (($token = array_shift($from)) !== null) {
            $diff[] = [$token, self::REMOVED];
        }

        while (($token = array_shift($to)) !== null) {
            $diff[] = [$token, self::ADDED];
        }

        foreach ($end as $token) {
            $diff[] = [$token, self::OLD];
        }

        if ($this->detectUnmatchedLineEndings($diff)) {
            array_unshift($diff, ["#Warning: Strings contain different line endings!\n", self::DIFF_LINE_END_WARNING]);
        }

        return $diff;
    }

    private function splitStringByLines(string $input): array
    {
        return preg_split('/(.*\R)/', $input, -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
    }

    private function selectLcsImplementation(array $from, array $to): LongestCommonSubsequenceCalculator
    {
        // We do not want to use the time-efficient implementation if its memory
        // footprint will probably exceed this value. Note that the footprint
        // calculation is only an estimation for the matrix and the LCS method
        // will typically allocate a bit more memory than this.
        $memoryLimit = 100 * 1024 * 1024;

        if ($this->calculateEstimatedFootprint($from, $to) > $memoryLimit) {
            return new MemoryEfficientLongestCommonSubsequenceCalculator;
        }

        return new TimeEfficientLongestCommonSubsequenceCalculator;
    }

    private function calculateEstimatedFootprint(array $from, array $to): float|int
    {
        $itemSize = PHP_INT_SIZE === 4 ? 76 : 144;

        return $itemSize * min(count($from), count($to)) ** 2;
    }

    private function detectUnmatchedLineEndings(array $diff): bool
    {
        $newLineBreaks = ['' => true];
        $oldLineBreaks = ['' => true];

        foreach ($diff as $entry) {
            if (self::OLD === $entry[1]) {
                $ln                 = $this->getLinebreak($entry[0]);
                $oldLineBreaks[$ln] = true;
                $newLineBreaks[$ln] = true;
            } elseif (self::ADDED === $entry[1]) {
                $newLineBreaks[$this->getLinebreak($entry[0])] = true;
            } elseif (self::REMOVED === $entry[1]) {
                $oldLineBreaks[$this->getLinebreak($entry[0])] = true;
            }
        }

        // if either input or output is a single line without breaks than no warning should be raised
        if (['' => true] === $newLineBreaks || ['' => true] === $oldLineBreaks) {
            return false;
        }

        // two-way compare
        foreach ($newLineBreaks as $break => $set) {
            if (!isset($oldLineBreaks[$break])) {
                return true;
            }
        }

        foreach ($oldLineBreaks as $break => $set) {
            if (!isset($newLineBreaks[$break])) {
                return true;
            }
        }

        return false;
    }

    private function getLinebreak($line): string
    {
        if (!is_string($line)) {
            return '';
        }

        $lc = substr($line, -1);

        if ("\r" === $lc) {
            return "\r";
        }

        if ("\n" !== $lc) {
            return '';
        }

        if (str_ends_with($line, "\r\n")) {
            return "\r\n";
        }

        return "\n";
    }

    private static function getArrayDiffParted(array &$from, array &$to): array
    {
        $start = [];
        $end   = [];

        reset($to);

        foreach ($from as $k => $v) {
            $toK = key($to);

            if ($toK === $k && $v === $to[$k]) {
                $start[$k] = $v;

                unset($from[$k], $to[$k]);
            } else {
                break;
            }
        }

        end($from);
        end($to);

        do {
            $fromK = key($from);
            $toK   = key($to);

            if (null === $fromK || null === $toK || current($from) !== current($to)) {
                break;
            }

            prev($from);
            prev($to);

            $end = [$fromK => $from[$fromK]] + $end;
            unset($from[$fromK], $to[$toK]);
        } while (true);

        return [$from, $to, $start, $end];
    }
}

• [D] Exception
• [D] Output
• [F] Chunk.php
  Delete
• [F] Diff.php
  Delete
• [F] Differ.php
  Delete
• [F] Line.php
  Delete
• [F] LongestCommonSubsequenceCalculator.php
  Delete
• [F] MemoryEfficientLongestCommonSubsequenceCalculator.php
  Delete
• [F] Parser.php
  Delete
• [F] TimeEfficientLongestCommonSubsequenceCalculator.php
  Delete

CUSTOMER COMPLAINT FORM

Please use this form to give us suggestions, compliments or complaints.
Click here to check complaint status.
Click here to show Term of Business Agreement

• Config option 1
• Config option 2

Salutation *

-- Please Choose -- Mr. Mrs. Ms. PT. CV. UD.

Name *

E-mail *

Account Type *

-- Please Choose -- Individual Company

Company Name *

Reference Number of Type Document *

-- Please Choose -- Policy Contract Invoice Number

*

About *

-- Please Choose -- Claim Service System

Risk *

-- Please Choose --

Subject *

Details *

Attachment

Add Attachment

Notes: *.png, *.jpg, *.jpeg, *.pdf, *.doc, *.docx, *.xls, *.xlsx, *.ppt, *.pptx, *.eml are allowed, and size must be smaller than 5Mb.

   Disclaimer :

• The information filled in form is true and valid. PT Howden Insurance Brokers Indonesia is not liable to any lawful obligations arising from any false or invalid information in this application form whatsoever, all the false or invalid information will not be processed.
• The client hereby agree to render PT Howden Insurance Brokers Indonesia a right to handle complaint including but not limited to grab data from records, emails, documents, confidential data, and others, liaise with relatable Parties e.g. (Insurer, Adjuster, Legal Advisor, etc) to settled complaint.
• The client hereby released PT Howden Insurance Brokers Indonesia from any material or immaterial damages if eventually, there is no evidence of damages caused by PT Howden Insurance Brokers Indonesia.

* is required

Clear Submit

Copyright © 2026 PT. Howden Insurance Brokers Indonesia. All rights reserved.
Authorised and regulated by Otoritas Jasa Keuangan (OJK).
Member of The Association of Indonesian Insurance & Reinsurance Brokers (APPARINDO).