League\CommonMark\Parser\InlineParserEngine

Complexity

Total Complexity

20

Size/Duplication

Total Lines	144
Duplicated Lines	0 %

Test Coverage

Coverage

100%

Importance

Changes	1
Bugs	0	Features	0

4 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	10	2
A	addPlainText()	0	7	3
B	matchParsers()	0	31	7
B	parse()	0	53	8

<?php

declare(strict_types=1);

/*
 * This file is part of the league/commonmark package.
 *
 * (c) Colin O'Dell <colinodell@gmail.com>
 *
 * Original code based on the CommonMark JS reference parser (https://bitly.com/commonmark-js)
 *  - (c) John MacFarlane
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace League\CommonMark\Parser;

use League\CommonMark\Environment\EnvironmentInterface;
use League\CommonMark\Node\Block\AbstractBlock;
use League\CommonMark\Node\Inline\AdjacentTextMerger;
use League\CommonMark\Node\Inline\Text;
use League\CommonMark\Node\Node;
use League\CommonMark\Parser\Inline\InlineParserInterface;
use League\CommonMark\Reference\ReferenceMapInterface;

/**
 * @internal
 */
final class InlineParserEngine implements InlineParserEngineInterface
{
    /**
     * @var EnvironmentInterface
     *
     * @psalm-readonly
     */
    private $environment;

    /**
     * @var ReferenceMapInterface
     *
     * @psalm-readonly
     */
    private $referenceMap;

    /**
     * @var array<int, InlineParserInterface|string|bool>
     * @psalm-var list<array{0: InlineParserInterface, 1: string, 2: bool}>
     * @phpstan-var array<int, array{0: InlineParserInterface, 1: string, 2: bool}>
     */
    private $parsers;

    public function __construct(EnvironmentInterface $environment, ReferenceMapInterface $referenceMap)
    {
        $this->environment  = $environment;
        $this->referenceMap = $referenceMap;

        foreach ($environment->getInlineParsers() as $parser) {
            \assert($parser instanceof InlineParserInterface);
            $regex = $parser->getMatchDefinition()->getRegex();

            $this->parsers[] = [$parser, $regex, \strlen($regex) !== \mb_strlen($regex)];
        }
    }

    public function parse(string $contents, AbstractBlock $block): void
    {
        $contents = \trim($contents);
        $cursor   = new Cursor($contents);

        $inlineParserContext = new InlineParserContext($cursor, $block, $this->referenceMap);

        // Have all parsers look at the line to determine what they might want to parse and what positions they exist at
        foreach ($this->matchParsers($contents) as $matchPosition => $parsers) {
            $currentPosition = $cursor->getPosition();
            // We've already gone past this point
            if ($currentPosition > $matchPosition) {
                continue;
            }

            // We've skipped over some uninteresting text that should be added as a plain text node
            if ($currentPosition < $matchPosition) {
                $cursor->advanceBy($matchPosition - $currentPosition);
                $this->addPlainText($cursor->getPreviousText(), $block);
            }

            // We're now at a potential start - see which of the current parsers can handle it
            $parsed = false;
            foreach ($parsers as [$parser, $match]) {
                \assert($parser instanceof InlineParserInterface);
                if ($parser->parse($match, $inlineParserContext)) {
                    // A parser has successfully handled the text at the given position; don't consider any others at this position
                    $parsed = true;
                    break;
                }
            }

            if ($parsed) {
                continue;
            }

            // Despite potentially being interested, nothing actually parsed text here, so add the current character and continue onwards
            $this->addPlainText((string) $cursor->getCharacter(), $block);
            $cursor->advance();
        }

        // Add any remaining text that wasn't parsed
        if (! $cursor->isAtEnd()) {
            $this->addPlainText($cursor->getRemainder(), $block);
        }

        // Process any delimiters that were found
        $delimiterStack = $inlineParserContext->getDelimiterStack();
        $delimiterStack->processDelimiters(null, $this->environment->getDelimiterProcessors());
        $delimiterStack->removeAll();

        // Combine adjacent text notes into one
        AdjacentTextMerger::mergeChildNodes($block);
    }

    private function addPlainText(string $text, Node $container): void
    {
        $lastInline = $container->lastChild();
        if ($lastInline instanceof Text && ! isset($lastInline->data['delim'])) {
            $lastInline->append($text);
        } else {
            $container->appendChild(new Text($text));
        }
    }

    /**
     * Given the current line, ask all the parsers which parts of the text they would be interested in parsing.
     *
     * The resulting array provides a list of character positions, which parsers are interested in trying to parse
     * the text at those points, and (for convenience/optimization) what the matching text happened to be.
     *
     * @return array<array<int, InlineParserInterface|string>>
     *
     * @psalm-return array<int, list<array{0: InlineParserInterface, 1: string}>>
     *
     * @phpstan-return array<int, array<int, array{0: InlineParserInterface, 1: string}>>
     */
    private function matchParsers(string $contents): array
    {
        $contents    = \trim($contents);
        $isMultibyte = \mb_strlen($contents) !== \strlen($contents);

        $ret = [];

        foreach ($this->parsers as [$parser, $regex, $isRegexMultibyte]) {
            if ($isMultibyte || $isRegexMultibyte) {
                $regex .= 'u';
            }

            if (! \preg_match_all($regex, $contents, $matches, \PREG_OFFSET_CAPTURE | \PREG_SET_ORDER)) {
                continue;
            }

            foreach ($matches as $match) {
                if ($isMultibyte) {
                    // PREG_OFFSET_CAPTURE always returns the byte offset, not the char offset, which is annoying
                    $offset = \mb_strlen(\substr($contents, 0, $match[0][1]), 'UTF-8');
                } else {
                    $offset = (int) $match[0][1];
                }

                $ret[$offset][] = [$parser, (string) $match[0][0]];
            }
        }

        \ksort($ret);

        return $ret;
    }
}