<?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\Parser as Rules;
class Blocks extends AbstractPass
{
/**
* @var array
*/
protected $setextLines = [];
/**
* {@inheritdoc}
*/
public function parse()
{
$this->matchSetextLines();
$blocks = [];
$blocksCnt = 0;
$codeFence = null;
$codeIndent = 4;
$codeTag = null;
$lineIsEmpty = true;
$lists = [];
$listsCnt = 0;
$newContext = false;
$textBoundary = 0;
$regexp = '/^(?:(?=[-*+\\d \\t>`~#_])((?: {0,3}>(?:(?!!)|!(?![^\\n>]*?!<)) ?)+)?([ \\t]+)?(\\* *\\* *\\*[* ]*$|- *- *-[- ]*$|_ *_ *_[_ ]*$|=+$)?((?:[-*+]|\\d+\\.)[ \\t]+(?=\\S))?[ \\t]*(#{1,6}[ \\t]+|```+[^`\\n]*$|~~~+[^~\\n]*$)?)?/m';
preg_match_all($regexp, $this->text, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER);
foreach ($matches as $m)
{
$blockDepth = 0;
$blockMarks = [];
$ignoreLen = 0;
$matchLen = strlen($m[0][0]);
$matchPos = $m[0][1];
// If the last line was empty then this is not a continuation, and vice-versa
$continuation = !$lineIsEmpty;
// Capture the position of the end of the line and determine whether the line is empty
$lfPos = $this->text->indexOf("\n", $matchPos);
$lineIsEmpty = ($lfPos === $matchPos + $matchLen && empty($m[3][0]) && empty($m[4][0]) && empty($m[5][0]));
// If the line is empty and it's the first empty line then we break current paragraph.
$breakParagraph = ($lineIsEmpty && $continuation);
// Count block marks
if (!empty($m[1][0]))
{
$blockMarks = $this->getBlockMarks($m[1][0]);
$blockDepth = count($blockMarks);
$ignoreLen = strlen($m[1][0]);
if (isset($codeTag) && $codeTag->hasAttribute('blockDepth'))
{
$blockDepth = min($blockDepth, $codeTag->getAttribute('blockDepth'));
$ignoreLen = $this->computeBlockIgnoreLen($m[1][0], $blockDepth);
}
// Overwrite block markup
$this->text->overwrite($matchPos, $ignoreLen);
}
// Close supernumerary blocks
if ($blockDepth < $blocksCnt && !$continuation)
{
$newContext = true;
do
{
$startTag = array_pop($blocks);
$this->parser->addEndTag($startTag->getName(), $textBoundary, 0)
->pairWith($startTag);
}
while ($blockDepth < --$blocksCnt);
}
// Open new blocks
if ($blockDepth > $blocksCnt && !$lineIsEmpty)
{
$newContext = true;
do
{
$tagName = ($blockMarks[$blocksCnt] === '>!') ? 'SPOILER' : 'QUOTE';
$blocks[] = $this->parser->addStartTag($tagName, $matchPos, 0, -999);
}
while ($blockDepth > ++$blocksCnt);
}
// Compute the width of the indentation
$indentWidth = 0;
$indentPos = 0;
if (!empty($m[2][0]) && !$codeFence)
{
$indentStr = $m[2][0];
$indentLen = strlen($indentStr);
do
{
if ($indentStr[$indentPos] === ' ')
{
++$indentWidth;
}
else
{
$indentWidth = ($indentWidth + 4) & ~3;
}
}
while (++$indentPos < $indentLen && $indentWidth < $codeIndent);
}
// Test whether we're out of a code block
if (isset($codeTag) && !$codeFence && $indentWidth < $codeIndent && !$lineIsEmpty)
{
$newContext = true;
}
if ($newContext)
{
$newContext = false;
// Close the code block if applicable
if (isset($codeTag))
{
if ($textBoundary > $codeTag->getPos())
{
// Overwrite the whole block
$this->text->overwrite($codeTag->getPos(), $textBoundary - $codeTag->getPos());
$codeTag->pairWith($this->parser->addEndTag('CODE', $textBoundary, 0, -1));
}
else
{
// The code block is empty
$codeTag->invalidate();
}
$codeTag = null;
$codeFence = null;
}
// Close all the lists
foreach ($lists as $list)
{
$this->closeList($list, $textBoundary);
}
$lists = [];
$listsCnt = 0;
// Mark the block boundary
if ($matchPos)
{
$this->text->markBoundary($matchPos - 1);
}
}
if ($indentWidth >= $codeIndent)
{
if (isset($codeTag) || !$continuation)
{
// Adjust the amount of text being ignored
$ignoreLen += $indentPos;
if (!isset($codeTag))
{
// Create code block
$codeTag = $this->parser->addStartTag('CODE', $matchPos + $ignoreLen, 0, -999);
}
// Clear the captures to prevent any further processing
$m = [];
}
}
elseif (!isset($codeTag))
{
$hasListItem = !empty($m[4][0]);
if (!$indentWidth && !$continuation && !$hasListItem)
{
// Start of a new context
$listIndex = -1;
}
elseif ($continuation && !$hasListItem)
{
// Continuation of current list item or paragraph
$listIndex = $listsCnt - 1;
}
elseif (!$listsCnt)
{
// We're not inside of a list already, we can start one if there's a list item
$listIndex = ($hasListItem) ? 0 : -1;
}
else
{
// We're inside of a list but we need to compute the depth
$listIndex = 0;
while ($listIndex < $listsCnt && $indentWidth > $lists[$listIndex]['maxIndent'])
{
++$listIndex;
}
}
// Close deeper lists
while ($listIndex < $listsCnt - 1)
{
$this->closeList(array_pop($lists), $textBoundary);
--$listsCnt;
}
// If there's no list item at current index, we'll need to either create one or
// drop down to previous index, in which case we have to adjust maxIndent
if ($listIndex === $listsCnt && !$hasListItem)
{
--$listIndex;
}
if ($hasListItem && $listIndex >= 0)
{
$breakParagraph = true;
// Compute the position and amount of text consumed by the item tag
$tagPos = $matchPos + $ignoreLen + $indentPos;
$tagLen = strlen($m[4][0]);
// Create a LI tag that consumes its markup
$itemTag = $this->parser->addStartTag('LI', $tagPos, $tagLen);
// Overwrite the markup
$this->text->overwrite($tagPos, $tagLen);
// If the list index is within current lists count it means this is not a new
// list and we have to close the last item. Otherwise, it's a new list that we
// have to create
if ($listIndex < $listsCnt)
{
$this->parser->addEndTag('LI', $textBoundary, 0)
->pairWith($lists[$listIndex]['itemTag']);
// Record the item in the list
$lists[$listIndex]['itemTag'] = $itemTag;
$lists[$listIndex]['itemTags'][] = $itemTag;
}
else
{
++$listsCnt;
if ($listIndex)
{
$minIndent = $lists[$listIndex - 1]['maxIndent'] + 1;
$maxIndent = max($minIndent, $listIndex * 4);
}
else
{
$minIndent = 0;
$maxIndent = $indentWidth;
}
// Create a 0-width LIST tag right before the item tag LI
$listTag = $this->parser->addStartTag('LIST', $tagPos, 0);
// Test whether the list item ends with a dot, as in "1."
if (strpos($m[4][0], '.') !== false)
{
$listTag->setAttribute('type', 'decimal');
$start = (int) $m[4][0];
if ($start !== 1)
{
$listTag->setAttribute('start', $start);
}
}
// Record the new list depth
$lists[] = [
'listTag' => $listTag,
'itemTag' => $itemTag,
'itemTags' => [$itemTag],
'minIndent' => $minIndent,
'maxIndent' => $maxIndent,
'tight' => true
];
}
}
// If we're in a list, on a non-empty line preceded with a blank line...
if ($listsCnt && !$continuation && !$lineIsEmpty)
{
// ...and this is not the first item of the list...
if (count($lists[0]['itemTags']) > 1 || !$hasListItem)
{
// ...every list that is currently open becomes loose
foreach ($lists as &$list)
{
$list['tight'] = false;
}
unset($list);
}
}
$codeIndent = ($listsCnt + 1) * 4;
}
if (isset($m[5]))
{
// Headers
if ($m[5][0][0] === '#')
{
$startLen = strlen($m[5][0]);
$startPos = $matchPos + $matchLen - $startLen;
$endLen = $this->getAtxHeaderEndTagLen($matchPos + $matchLen, $lfPos);
$endPos = $lfPos - $endLen;
$this->parser->addTagPair('H' . strspn($m[5][0], '#', 0, 6), $startPos, $startLen, $endPos, $endLen);
// Mark the start and the end of the header as boundaries
$this->text->markBoundary($startPos);
$this->text->markBoundary($lfPos);
if ($continuation)
{
$breakParagraph = true;
}
}
// Code fence
elseif ($m[5][0][0] === '`' || $m[5][0][0] === '~')
{
$tagPos = $matchPos + $ignoreLen;
$tagLen = $lfPos - $tagPos;
if (isset($codeTag) && $m[5][0] === $codeFence)
{
$codeTag->pairWith($this->parser->addEndTag('CODE', $tagPos, $tagLen, -1));
$this->parser->addIgnoreTag($textBoundary, $tagPos - $textBoundary);
// Overwrite the whole block
$this->text->overwrite($codeTag->getPos(), $tagPos + $tagLen - $codeTag->getPos());
$codeTag = null;
$codeFence = null;
}
elseif (!isset($codeTag))
{
// Create code block
$codeTag = $this->parser->addStartTag('CODE', $tagPos, $tagLen);
$codeFence = substr($m[5][0], 0, strspn($m[5][0], '`~'));
$codeTag->setAttribute('blockDepth', $blockDepth);
// Ignore the next character, which should be a newline
$this->parser->addIgnoreTag($tagPos + $tagLen, 1);
// Add the language if present, e.g. ```php
$lang = trim(trim($m[5][0], '`~'));
if ($lang !== '')
{
$codeTag->setAttribute('lang', $lang);
}
}
}
}
elseif (!empty($m[3][0]) && !$listsCnt && $this->text->charAt($matchPos + $matchLen) !== "\x17")
{
// Horizontal rule
$this->parser->addSelfClosingTag('HR', $matchPos + $ignoreLen, $matchLen - $ignoreLen);
$breakParagraph = true;
// Mark the end of the line as a boundary
$this->text->markBoundary($lfPos);
}
elseif (isset($this->setextLines[$lfPos]) && $this->setextLines[$lfPos]['blockDepth'] === $blockDepth && !$lineIsEmpty && !$listsCnt && !isset($codeTag))
{
// Setext-style header
$this->parser->addTagPair(
$this->setextLines[$lfPos]['tagName'],
$matchPos + $ignoreLen,
0,
$this->setextLines[$lfPos]['endPos'],
$this->setextLines[$lfPos]['endLen']
);
// Mark the end of the Setext line
$this->text->markBoundary($this->setextLines[$lfPos]['endPos'] + $this->setextLines[$lfPos]['endLen']);
}
if ($breakParagraph)
{
$this->parser->addParagraphBreak($textBoundary);
$this->text->markBoundary($textBoundary);
}
if (!$lineIsEmpty)
{
$textBoundary = $lfPos;
}
if ($ignoreLen)
{
$this->parser->addIgnoreTag($matchPos, $ignoreLen, 1000);
}
}
}
/**
* Close a list at given offset
*
* @param array $list
* @param integer $textBoundary
* @return void
*/
protected function closeList(array $list, $textBoundary)
{
$this->parser->addEndTag('LIST', $textBoundary, 0)->pairWith($list['listTag']);
$this->parser->addEndTag('LI', $textBoundary, 0)->pairWith($list['itemTag']);
if ($list['tight'])
{
foreach ($list['itemTags'] as $itemTag)
{
$itemTag->removeFlags(Rules::RULE_CREATE_PARAGRAPHS);
}
}
}
/**
* Compute the amount of text to ignore at the start of a block line
*
* @param string $str Original block markup
* @param integer $maxBlockDepth Maximum block depth
* @return integer Number of characters to ignore
*/
protected function computeBlockIgnoreLen($str, $maxBlockDepth)
{
$remaining = $str;
while (--$maxBlockDepth >= 0)
{
$remaining = preg_replace('/^ *>!? ?/', '', $remaining);
}
return strlen($str) - strlen($remaining);
}
/**
* Return the length of the markup at the end of an ATX header
*
* @param integer $startPos Start of the header's text
* @param integer $endPos End of the header's text
* @return integer
*/
protected function getAtxHeaderEndTagLen($startPos, $endPos)
{
$content = substr($this->text, $startPos, $endPos - $startPos);
preg_match('/[ \\t]*#*[ \\t]*$/', $content, $m);
return strlen($m[0]);
}
/**
* Capture and return block marks from given string
*
* @param string $str Block markup, composed of ">", "!" and whitespace
* @return string[]
*/
protected function getBlockMarks($str)
{
preg_match_all('(>!?)', $str, $m);
return $m[0];
}
/**
* Capture and store lines that contain a Setext-tyle header
*
* @return void
*/
protected function matchSetextLines()
{
if ($this->text->indexOf('-') === false && $this->text->indexOf('=') === false)
{
return;
}
// Capture the any series of - or = alone on a line, optionally preceded with the
// angle brackets notation used in block markup
$regexp = '/^(?=[-=>])(?:>!? ?)*(?=[-=])(?:-+|=+) *$/m';
if (!preg_match_all($regexp, $this->text, $matches, PREG_OFFSET_CAPTURE))
{
return;
}
foreach ($matches[0] as list($match, $matchPos))
{
// Compute the position of the end tag. We start on the LF character before the
// match and keep rewinding until we find a non-space character
$endPos = $matchPos - 1;
while ($endPos > 0 && $this->text->charAt($endPos - 1) === ' ')
{
--$endPos;
}
// Store at the offset of the LF character
$this->setextLines[$matchPos - 1] = [
'endLen' => $matchPos + strlen($match) - $endPos,
'endPos' => $endPos,
'blockDepth' => substr_count($match, '>'),
'tagName' => ($match[0] === '=') ? 'H1' : 'H2'
];
}
}
}