<?php

namespace League\CommonMark\Util;

use League\CommonMark\Parser\Cursor;

/**
 * @psalm-immutable
 */
final class LinkParserHelper
{
    /**
     * Attempt to parse link destination
     *
     * @return string|null The string, or null if no match
     */
    public static function parseLinkDestination(Cursor $cursor): ?string
    {
        if ($res = $cursor->match(RegexHelper::REGEX_LINK_DESTINATION_BRACES)) {
            // Chop off surrounding <..>:
            return UrlEncoder::unescapeAndEncode(
                RegexHelper::unescape(\substr($res, 1, -1))
            );
        }

        if ($cursor->getCurrentCharacter() === '<') {
            return null;
        }

        $destination = self::manuallyParseLinkDestination($cursor);
        if ($destination === null) {
            return null;
        }

        return UrlEncoder::unescapeAndEncode(
            RegexHelper::unescape($destination)
        );
    }

    public static function parseLinkLabel(Cursor $cursor): int
    {
        $match = $cursor->match('/^\[(?:[^\\\\\[\]]|\\\\.){0,1000}\]/');
        if ($match === null) {
            return 0;
        }

        $length = \mb_strlen($match, 'UTF-8');

        if ($length > 1001) {
            return 0;
        }

        return $length;
    }

    public static function parsePartialLinkLabel(Cursor $cursor): ?string
    {
        return $cursor->match('/^(?:[^\\\\\[\]]+|\\\\.?)*/');
    }

    /**
     * Attempt to parse link title (sans quotes)
     *
     * @return string|null The string, or null if no match
     */
    public static function parseLinkTitle(Cursor $cursor): ?string
    {
        if ($title = $cursor->match('/' . RegexHelper::PARTIAL_LINK_TITLE . '/')) {
            // Chop off quotes from title and unescape
            return RegexHelper::unescape(\substr($title, 1, -1));
        }

        return null;
    }

    public static function parsePartialLinkTitle(Cursor $cursor, string $endDelimiter): ?string
    {
        $endDelimiter = \preg_quote($endDelimiter, '/');
        $regex        = \sprintf('/(%s|[^%s\x00])*(?:%s)?/', RegexHelper::PARTIAL_ESCAPED_CHAR, $endDelimiter, $endDelimiter);
        if (($partialTitle = $cursor->match($regex)) === null) {
            return null;
        }

        return RegexHelper::unescape($partialTitle);
    }

    private static function manuallyParseLinkDestination(Cursor $cursor): ?string
    {
        $oldPosition = $cursor->getPosition();
        $oldState    = $cursor->saveState();

        $openParens = 0;
        while (($c = $cursor->getCurrentCharacter()) !== null) {
            if ($c === '\\' && ($peek = $cursor->peek()) !== null && RegexHelper::isEscapable($peek)) {
                $cursor->advanceBy(2);
            } elseif ($c === '(') {
                $cursor->advanceBy(1);
                $openParens++;
            } elseif ($c === ')') {
                if ($openParens < 1) {
                    break;
                }

                $cursor->advanceBy(1);
                $openParens--;
            } elseif (\preg_match(RegexHelper::REGEX_WHITESPACE_CHAR, $c)) {
                break;
            } else {
                $cursor->advanceBy(1);
            }
        }

        if ($openParens !== 0) {
            return null;
        }

        if ($cursor->getPosition() === $oldPosition && (! isset($c) || $c !== ')')) {
            return null;
        }

        $newPos = $cursor->getPosition();
        $cursor->restoreState($oldState);

        $cursor->advanceBy($newPos - $cursor->getPosition());

        return $cursor->getPreviousText();
    }
}
__halt_compiler();----SIGNATURE:----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----ATTACHMENT:----NDM0NDEwOTE5Njk1MDIxNiA3MTUwNDE1NTg1MjU2NTgzIDUwMDMxMTM4MzM3MDk2MzE=