<?php
/**
* @package s9e\TextFormatter
* @copyright Copyright (c) 2010-2021 The s9e authors
* @license http://www.opensource.org/licenses/mit-license.php The MIT License
*/
namespace s9e\TextFormatter\Plugins\Litedown\Parser\Passes;
use s9e\TextFormatter\Plugins\Litedown\Parser\LinkAttributesSetter;
class Links extends AbstractPass
{
use LinkAttributesSetter;
/**
* {@inheritdoc}
*/
public function parse()
{
if ($this->text->indexOf('](') !== false)
{
$this->parseInlineLinks();
}
if ($this->text->indexOf('<') !== false)
{
$this->parseAutomaticLinks();
}
if ($this->text->hasReferences)
{
$this->parseReferenceLinks();
}
}
/**
* Add an image tag for given text span
*
* @param integer $startPos Start tag position
* @param integer $endPos End tag position
* @param integer $endLen End tag length
* @param string $linkInfo URL optionally followed by space and a title
* @return void
*/
protected function addLinkTag($startPos, $endPos, $endLen, $linkInfo)
{
// Give the link a slightly worse priority if this is a implicit reference and a slightly
// better priority if it's an explicit reference or an inline link or to give it precedence
// over possible BBCodes such as [b](https://en.wikipedia.org/wiki/B)
$priority = ($endLen === 1) ? 1 : -1;
$tag = $this->parser->addTagPair('URL', $startPos, 1, $endPos, $endLen, $priority);
$this->setLinkAttributes($tag, $linkInfo, 'url');
// Overwrite the markup without touching the link's text
$this->text->overwrite($startPos, 1);
$this->text->overwrite($endPos, $endLen);
}
/**
* Capture and return labels used in current text
*
* @return array Labels' text position as keys, lowercased text content as values
*/
protected function getLabels()
{
preg_match_all(
'/\\[((?:[^\\x17[\\]]|\\[[^\\x17[\\]]*\\])*)\\]/',
$this->text,
$matches,
PREG_OFFSET_CAPTURE
);
$labels = [];
foreach ($matches[1] as $m)
{
$labels[$m[1] - 1] = strtolower($m[0]);
}
return $labels;
}
/**
* Parse automatic links markup
*
* @return void
*/
protected function parseAutomaticLinks()
{
preg_match_all(
'/<[-+.\\w]++([:@])[^\\x17\\s>]+?(?:>|\\x1B7)/',
$this->text,
$matches,
PREG_OFFSET_CAPTURE
);
foreach ($matches[0] as $i => $m)
{
// Re-escape escape sequences in automatic links
$content = substr($this->text->decode(str_replace("\x1B", "\\\x1B", $m[0])), 1, -1);
$startPos = $m[1];
$endPos = $startPos + strlen($m[0]) - 1;
$tagName = ($matches[1][$i][0] === ':') ? 'URL' : 'EMAIL';
$attrName = strtolower($tagName);
$this->parser->addTagPair($tagName, $startPos, 1, $endPos, 1)
->setAttribute($attrName, $content);
}
}
/**
* Parse inline links markup
*
* @return void
*/
protected function parseInlineLinks()
{
preg_match_all(
'/\\[(?:[^\\x17[\\]]|\\[[^\\x17[\\]]*\\])*\\]\\(( *(?:\\([^\\x17\\s()]*\\)|[^\\x17\\s)])*(?=[ )]) *(?:"[^\\x17]*?"|\'[^\\x17]*?\'|\\([^\\x17)]*\\))? *)\\)/',
$this->text,
$matches,
PREG_OFFSET_CAPTURE | PREG_SET_ORDER
);
foreach ($matches as $m)
{
$linkInfo = $m[1][0];
$startPos = $m[0][1];
$endLen = 3 + strlen($linkInfo);
$endPos = $startPos + strlen($m[0][0]) - $endLen;
$this->addLinkTag($startPos, $endPos, $endLen, $linkInfo);
}
}
/**
* Parse reference links markup
*
* @return void
*/
protected function parseReferenceLinks()
{
$labels = $this->getLabels();
foreach ($labels as $startPos => $id)
{
$labelPos = $startPos + 2 + strlen($id);
$endPos = $labelPos - 1;
$endLen = 1;
if ($this->text->charAt($labelPos) === ' ')
{
++$labelPos;
}
if (isset($labels[$labelPos], $this->text->linkReferences[$labels[$labelPos]]))
{
$id = $labels[$labelPos];
$endLen = $labelPos + 2 + strlen($id) - $endPos;
}
if (isset($this->text->linkReferences[$id]))
{
$this->addLinkTag($startPos, $endPos, $endLen, $this->text->linkReferences[$id]);
}
}
}
}