<?php
/**
 * Converter
 *
 * @package RosarioSIS
 * @subpackage classes/Markdownify
 */

namespace Markdownify;

/**
 * default configuration
 */
define('MDFY_BODYWIDTH', false);
define('MDFY_KEEPHTML', true);

/**
 * HTML to Markdown converter class
 */
class Converter
{
	/**
	 * html parser object
	 *
	 * @var parseHTML
	 */
	protected $parser;

	/**
	 * markdown output
	 *
	 * @var string
	 */
	protected $output;

	/**
	 * stack with tags which where not converted to html
	 *
	 * @var array<string>
	 */
	protected $notConverted = [];

	/**
	 * skip conversion to markdown
	 *
	 * @var bool
	 */
	protected $skipConversion = false;

	/* options */

	/**
	 * keep html tags which cannot be converted to markdown
	 *
	 * @var bool
	 */
	protected $keepHTML = false;

	/**
	 * wrap output, set to 0 to skip wrapping
	 *
	 * @var int
	 */
	protected $bodyWidth = 0;

	/**
	 * minimum body width
	 *
	 * @var int
	 */
	protected $minBodyWidth = 25;

	/**
	 * position where the link reference will be displayed
	 *
	 *
	 * @var int
	 */
	protected $linkPosition;
	const LINK_AFTER_CONTENT = 0;
	const LINK_AFTER_PARAGRAPH = 1;
	const LINK_IN_PARAGRAPH = 2;

	/**
	 * stores current buffers
	 *
	 * @var array<string>
	 */
	protected $buffer = [];

	/**
	 * stores current buffers
	 *
	 * @var array<string>
	 */
	protected $footnotes = [];

	/**
	 * tags with elements which can be handled by markdown
	 *
	 * @var array<string>
	 */
	protected $isMarkdownable = [
		'p' => [],
		'ul' => [],
		'ol' => [],
		'li' => [],
		'br' => [],
		'blockquote' => [],
		'code' => [],
		'pre' => [],
		'a' => [
			'href' => 'required',
			'title' => 'optional',
		],
		'strong' => [],
		'b' => [],
		'em' => [],
		'i' => [],
		'img' => [
			'src' => 'required',
			'alt' => 'optional',
			'title' => 'optional',
		],
		'h1' => [],
		'h2' => [],
		'h3' => [],
		'h4' => [],
		'h5' => [],
		'h6' => [],
		'hr' => [],
	];

	/**
	 * html tags to be ignored (contents will be parsed)
	 *
	 * @var array<string>
	 */
	protected $ignore = [
		'html',
		'body',
	];

	/**
	 * html tags to be dropped (contents will not be parsed!)
	 *
	 * @var array<string>
	 */
	protected $drop = [
		'script',
		'head',
		'style',
		'form',
		'area',
		'object',
		'param',
		'iframe',
	];

	/**
	 * html block tags that allow inline & block children
	 *
	 * @var array<string>
	 */
	protected $allowMixedChildren = [
		'li'
	];

	/**
	 * Markdown indents which could be wrapped
	 * @note: use strings in regex format
	 *
	 * @var array<string>
	 */
	protected $wrappableIndents = [
		'\*   ', // ul
		'\d.  ', // ol
		'\d\d. ', // ol
		'> ', // blockquote
		'', // p
	];

	/**
	 * list of chars which have to be escaped in normal text
	 * @note: use strings in regex format
	 *
	 * @var array
	 *
	 * TODO: what's with block chars / sequences at the beginning of a block?
	 */
	protected $escapeInText = [
		'\*\*([^*]+)\*\*' => '\*\*$1\*\*', // strong
		'\*([^*]+)\*' => '\*$1\*', // em
		'__(?! |_)(.+)(?!<_| )__' => '\_\_$1\_\_', // strong
		'_(?! |_)(.+)(?!<_| )_' => '\_$1\_', // em
		'([-*_])([ ]{0,2}\1){2,}' => '\\\\$0', // hr
		'`' => '\`', // code
		'\[(.+)\](\s*\()' => '\[$1\]$2', // links: [text] (url) => [text\] (url)
		'\[(.+)\](\s*)\[(.*)\]' => '\[$1\]$2\[$3\]', // links: [text][id] => [text\][id\]
		'^#(#{0,5}) ' => '\#$1 ', // header
	];

	/**
	 * wether last processed node was a block tag or not
	 *
	 * @var bool
	 */
	protected $lastWasBlockTag = false;

	/**
	 * name of last closed tag
	 *
	 * @var string
	 */
	protected $lastClosedTag = '';

	/**
	 * number of line breaks before next inline output
	 */
	protected $lineBreaks = 0;

	/**
	 * node stack, e.g. for <a> and <abbr> tags
	 *
	 * @var array<array>
	 */
	protected $stack = [];

	/**
	 * current indentation
	 *
	 * @var string
	 */
	protected $indent = '';

	/**
	 * constructor, set options, setup parser
	 *
	 * @param int $linkPosition define the position of links
	 * @param int $bodyWidth whether or not to wrap the output to the given width
	 *             defaults to false
	 * @param bool $keepHTML whether to keep non markdownable HTML or to discard it
	 *             defaults to true (HTML will be kept)
	 * @return void
	 */
	public function __construct($linkPosition = self::LINK_AFTER_CONTENT, $bodyWidth = MDFY_BODYWIDTH, $keepHTML = MDFY_KEEPHTML)
	{
		$this->linkPosition = $linkPosition;
		$this->keepHTML = $keepHTML;

		if ($bodyWidth > $this->minBodyWidth) {
			$this->bodyWidth = intval($bodyWidth);
		} else {
			$this->bodyWidth = false;
		}

		$this->parser = new Parser;
		$this->parser->noTagsInCode = true;

		// we don't have to do this every time
		$search = [];
		$replace = [];
		foreach ($this->escapeInText as $s => $r) {
			array_push($search, '@(?<!\\\)' . $s . '@U');
			array_push($replace, $r);
		}
		$this->escapeInText = [
			'search' => $search,
			'replace' => $replace
		];
	}

	/**
	 * parse a HTML string
	 *
	 * @param string $html
	 * @return string markdown formatted
	 */
	public function parseString($html)
	{
		$this->resetState();

		$this->parser->html = $html;
		$this->parse();

		return $this->output;
	}

	/**
	 * set the position where the link reference will be displayed
	 *
	 * @param int $linkPosition
	 * @return void
	 */
	public function setLinkPosition($linkPosition)
	{
		$this->linkPosition = $linkPosition;
	}

	/**
	 * set keep HTML tags which cannot be converted to markdown
	 *
	 * @param bool $linkPosition
	 * @return void
	 */
	public function setKeepHTML($keepHTML)
	{
		$this->keepHTML = $keepHTML;
	}

	/**
	 * iterate through the nodes and decide what we
	 * shall do with the current node
	 *
	 * @param void
	 * @return void
	 */
	protected function parse()
	{
		$this->output = '';
		// drop tags
		$this->parser->html = preg_replace('#<(' . implode('|', $this->drop) . ')[^>]*>.*</\\1>#sU', '', $this->parser->html);
		while ($this->parser->nextNode()) {
			switch ($this->parser->nodeType) {
				case 'doctype':
					break;
				case 'pi':
				case 'comment':
					if ($this->keepHTML) {
						$this->flushLinebreaks();
						$this->out($this->parser->node);
						$this->setLineBreaks(2);
					}
					// else drop
					break;
				case 'text':
					$this->handleText();
					break;
				case 'tag':
					if (in_array($this->parser->tagName, $this->ignore)) {
						break;
					}
					// If the previous tag was not a block element, we simulate a paragraph tag
					if ($this->parser->isBlockElement && $this->parser->isNextToInlineContext && !in_array($this->parent(), $this->allowMixedChildren)) {
						$this->setLineBreaks(2);
					}
					if ($this->parser->isStartTag) {
						$this->flushLinebreaks();
					}
					if ($this->skipConversion) {
						$this->isMarkdownable(); // update notConverted
						$this->handleTagToText();
						break;
					}

					// block elements
					if (!$this->parser->keepWhitespace && $this->parser->isBlockElement) {
						$this->fixBlockElementSpacing();
					}

					// inline elements
					if (!$this->parser->keepWhitespace && $this->parser->isInlineContext) {
						$this->fixInlineElementSpacing();
					}

					if ($this->isMarkdownable()) {
						if ($this->parser->isBlockElement && $this->parser->isStartTag && !$this->lastWasBlockTag && !empty($this->output)) {
							if (!empty($this->buffer)) {
								$str =& $this->buffer[count($this->buffer) - 1];
							} else {
								$str =& $this->output;
							}
							if (substr($str, -strlen($this->indent) - 1) != "\n" . $this->indent) {
								$str .= "\n" . $this->indent;
							}
						}
						$func = 'handleTag_' . $this->parser->tagName;
						$this->$func();
						if ($this->linkPosition == self::LINK_AFTER_PARAGRAPH && $this->parser->isBlockElement && !$this->parser->isStartTag && empty($this->parser->openTags)) {
							$this->flushFootnotes();
						}
						if (!$this->parser->isStartTag) {
							$this->lastClosedTag = $this->parser->tagName;
						}
					} else {
						$this->handleTagToText();
						$this->lastClosedTag = '';
					}
					break;
				default:
					trigger_error('invalid node type', E_USER_ERROR);
					break;
			}
			$this->lastWasBlockTag = $this->parser->nodeType == 'tag' && $this->parser->isStartTag && $this->parser->isBlockElement;
		}
		if (!empty($this->buffer)) {
			// trigger_error('buffer was not flushed, this is a bug. please report!', E_USER_WARNING);
			while (!empty($this->buffer)) {
				$this->out($this->unbuffer());
			}
		}
		// cleanup
		$this->output = rtrim(str_replace('&amp;', '&', str_replace('&lt;', '<', str_replace('&gt;', '>', $this->output))));
		// end parsing, flush stacked tags
		$this->flushFootnotes();
		$this->stack = [];
	}

	/**
	 * check if current tag can be converted to Markdown
	 *
	 * @param void
	 * @return bool
	 */
	protected function isMarkdownable()
	{
		if (!isset($this->isMarkdownable[$this->parser->tagName])) {
			// simply not markdownable

			return false;
		}
		if ($this->parser->isStartTag) {
			$return = true;
			if ($this->keepHTML) {
				$diff = array_diff(array_keys($this->parser->tagAttributes), array_keys($this->isMarkdownable[$this->parser->tagName]));
				if (!empty($diff)) {
					// non markdownable attributes given
					$return = false;
				}
			}
			if ($return) {
				foreach ($this->isMarkdownable[$this->parser->tagName] as $attr => $type) {
					if ($type == 'required' && !isset($this->parser->tagAttributes[$attr])) {
						// required markdown attribute not given
						$return = false;
						break;
					}
				}
			}
			if (!$return) {
				array_push($this->notConverted, $this->parser->tagName . '::' . implode('/', $this->parser->openTags));
			}

			return $return;
		} else {
			if (!empty($this->notConverted) && end($this->notConverted) === $this->parser->tagName . '::' . implode('/', $this->parser->openTags)) {
				array_pop($this->notConverted);

				return false;
			}

			return true;
		}
	}

	/**
	 * output footnotes
	 *
	 * @param void
	 * @return void
	 */
	protected function flushFootnotes()
	{
		$out = false;
		foreach ($this->footnotes as $k => $tag) {
			if (!isset($tag['unstacked'])) {
				if (!$out) {
					$out = true;
					$this->out("\n\n", true);
				} else {
					$this->out("\n", true);
				}
				$this->out(' [' . $tag['linkID'] . ']: ' . $this->getLinkReference($tag), true);
				$tag['unstacked'] = true;
				$this->footnotes[$k] = $tag;
			}
		}
	}

	/**
	 * return formated link reference
	 *
	 * @param array $tag
	 * @return string link reference
	 */
	protected function getLinkReference($tag)
	{
		return $tag['href'] . (isset($tag['title']) ? ' "' . $tag['title'] . '"' : '');
	}

	/**
	 * flush enqued linebreaks
	 *
	 * @param void
	 * @return void
	 */
	protected function flushLinebreaks()
	{
		if ($this->lineBreaks && !empty($this->output)) {
			$this->out(str_repeat("\n" . $this->indent, $this->lineBreaks), true);
		}
		$this->lineBreaks = 0;
	}

	/**
	 * handle non Markdownable tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTagToText()
	{
		if (!$this->keepHTML) {
			if (!$this->parser->isStartTag && $this->parser->isBlockElement) {
				$this->setLineBreaks(2);
			}
		} else {
			// don't convert to markdown inside this tag
			/** TODO: markdown extra **/
			if (!$this->parser->isEmptyTag) {
				if ($this->parser->isStartTag) {
					if (!$this->skipConversion) {
						$this->skipConversion = $this->parser->tagName . '::' . implode('/', $this->parser->openTags);
					}
				} else {
					if ($this->skipConversion == $this->parser->tagName . '::' . implode('/', $this->parser->openTags)) {
						$this->skipConversion = false;
					}
				}
			}

			if ($this->parser->isBlockElement) {
				if ($this->parser->isStartTag) {
					// looks like ins or del are block elements now
					if (in_array($this->parent(), ['ins', 'del'])) {
						$this->out("\n", true);
						$this->indent('  ');
					}
					// don't indent inside <pre> tags
					if ($this->parser->tagName == 'pre') {
						$this->out($this->parser->node);
						static $indent;
						$indent = $this->indent;
						$this->indent = '';
					} else {
						$this->out($this->parser->node . "\n" . $this->indent);
						if (!$this->parser->isEmptyTag) {
							$this->indent('  ');
						} else {
							$this->setLineBreaks(1);
						}
						$this->parser->html = ltrim($this->parser->html);
					}
				} else {
					if (!$this->parser->keepWhitespace) {
						$this->output = rtrim($this->output);
					}
					if ($this->parser->tagName != 'pre') {
						$this->indent('  ');
						$this->out("\n" . $this->indent . $this->parser->node);
					} else {
						// reset indentation
						$this->out($this->parser->node);
						static $indent;
						$this->indent = $indent;
					}

					if (in_array($this->parent(), ['ins', 'del'])) {
						// ins or del was block element
						$this->out("\n");
						$this->indent('  ');
					}
					if ($this->parser->tagName == 'li') {
						$this->setLineBreaks(1);
					} else {
						$this->setLineBreaks(2);
					}
				}
			} else {
				$this->out($this->parser->node);
			}
			if (in_array($this->parser->tagName, ['code', 'pre'])) {
				if ($this->parser->isStartTag) {
					$this->buffer();
				} else {
					// add stuff so cleanup just reverses this
					$this->out(str_replace('&lt;', '&amp;lt;', str_replace('&gt;', '&amp;gt;', $this->unbuffer())));
				}
			}
		}
	}

	/**
	 * handle plain text
	 *
	 * @param void
	 * @return void
	 */
	protected function handleText()
	{
		if ($this->hasParent('pre') && strpos($this->parser->node, "\n") !== false) {
			$this->parser->node = str_replace("\n", "\n" . $this->indent, $this->parser->node);
		}
		if (!$this->hasParent('code') && !$this->hasParent('pre')) {
			// entity decode
			$this->parser->node = $this->decode($this->parser->node);
			if (!$this->skipConversion) {
				// escape some chars in normal Text
				$this->parser->node = preg_replace($this->escapeInText['search'], $this->escapeInText['replace'], $this->parser->node);
			}
		} else {
			$this->parser->node = str_replace(['&quot;', '&apos'], ['"', '\''], $this->parser->node);
		}
		$this->out($this->parser->node);
		$this->lastClosedTag = '';
	}

	/**
	 * handle <em> and <i> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_em()
	{
		$this->out('_', true);
	}

	protected function handleTag_i()
	{
		$this->handleTag_em();
	}

	/**
	 * handle <strong> and <b> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_strong()
	{
		$this->out('**', true);
	}

	protected function handleTag_b()
	{
		$this->handleTag_strong();
	}

	/**
	 * handle <h1> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_h1()
	{
		$this->handleHeader(1);
	}

	/**
	 * handle <h2> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_h2()
	{
		$this->handleHeader(2);
	}

	/**
	 * handle <h3> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_h3()
	{
		$this->handleHeader(3);
	}

	/**
	 * handle <h4> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_h4()
	{
		$this->handleHeader(4);
	}

	/**
	 * handle <h5> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_h5()
	{
		$this->handleHeader(5);
	}

	/**
	 * handle <h6> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_h6()
	{
		$this->handleHeader(6);
	}

	/**
	 * handle header tags (<h1> - <h6>)
	 *
	 * @param int $level 1-6
	 * @return void
	 */
	protected function handleHeader($level)
	{
		if ($this->parser->isStartTag) {
			$this->out(str_repeat('#', $level) . ' ', true);
		} else {
			$this->setLineBreaks(2);
		}
	}

	/**
	 * handle <p> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_p()
	{
		if (!$this->parser->isStartTag) {
			$this->setLineBreaks(2);
		}
	}

	/**
	 * handle <a> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_a()
	{
		if ($this->parser->isStartTag) {
			$this->buffer();
			$this->handleTag_a_parser();
			$this->stack();
		} else {
			$tag = $this->unstack();
			$buffer = $this->unbuffer();
			$this->handleTag_a_converter($tag, $buffer);
			$this->out($this->handleTag_a_converter($tag, $buffer), true);
		}
	}

	/**
	 * handle <a> tags parsing
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_a_parser()
	{
		if (isset($this->parser->tagAttributes['title'])) {
			$this->parser->tagAttributes['title'] = $this->decode($this->parser->tagAttributes['title']);
		} else {
			$this->parser->tagAttributes['title'] = null;
		}
		$this->parser->tagAttributes['href'] = $this->decode(trim($this->parser->tagAttributes['href']));
	}

	/**
	 * handle <a> tags conversion
	 *
	 * @param array $tag
	 * @param string $buffer
	 * @return string The markdownified link
	 */
	protected function handleTag_a_converter($tag, $buffer)
	{
		if (empty($tag['href']) && empty($tag['title'])) {
			// empty links... testcase mania, who would possibly do anything like that?!
			return '[' . $buffer . ']()';
		}

		if ($buffer == $tag['href'] && empty($tag['title'])) {
			// <http://example.com>
			return '<' . $buffer . '>';
		}

		$bufferDecoded = $this->decode(trim($buffer));
		if (substr($tag['href'], 0, 7) == 'mailto:' && 'mailto:' . $bufferDecoded == $tag['href']) {
			if (is_null($tag['title'])) {
				// <mail@example.com>
				return '<' . $bufferDecoded . '>';
			}
			// [mail@example.com][1]
			// ...
			//  [1]: mailto:mail@example.com Title
			$tag['href'] = 'mailto:' . $bufferDecoded;
		}

		if ($this->linkPosition == self::LINK_IN_PARAGRAPH) {
			return '[' . $buffer . '](' . $this->getLinkReference($tag) . ')';
		}

		// [This link][id]
		foreach ($this->footnotes as $tag2) {
			if ($tag2['href'] == $tag['href'] && $tag2['title'] === $tag['title']) {
				$tag['linkID'] = $tag2['linkID'];
				break;
			}
		}
		if (!isset($tag['linkID'])) {
			$tag['linkID'] = count($this->footnotes) + 1;
			array_push($this->footnotes, $tag);
		}

		return '[' . $buffer . '][' . $tag['linkID'] . ']';
	}

	/**
	 * handle <img /> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_img()
	{
		if (!$this->parser->isStartTag) {
			return; // just to be sure this is really an empty tag...
		}

		if (isset($this->parser->tagAttributes['title'])) {
			$this->parser->tagAttributes['title'] = $this->decode($this->parser->tagAttributes['title']);
		} else {
			$this->parser->tagAttributes['title'] = null;
		}
		if (isset($this->parser->tagAttributes['alt'])) {
			$this->parser->tagAttributes['alt'] = $this->decode($this->parser->tagAttributes['alt']);
		} else {
			$this->parser->tagAttributes['alt'] = null;
		}

		if (empty($this->parser->tagAttributes['src'])) {
			// support for "empty" images... dunno if this is really needed
			// but there are some test cases which do that...
			if (!empty($this->parser->tagAttributes['title'])) {
				$this->parser->tagAttributes['title'] = ' ' . $this->parser->tagAttributes['title'] . ' ';
			}
			$this->out('![' . $this->parser->tagAttributes['alt'] . '](' . $this->parser->tagAttributes['title'] . ')', true);

			return;
		} else {
			$this->parser->tagAttributes['src'] = $this->decode($this->parser->tagAttributes['src']);
		}

		$out = '![' . $this->parser->tagAttributes['alt'] . ']';
		if ($this->linkPosition == self::LINK_IN_PARAGRAPH) {
			$out .= '(' . $this->parser->tagAttributes['src'];
			if ($this->parser->tagAttributes['title']) {
				$out .= ' "' . $this->parser->tagAttributes['title'] . '"';
			}
			$out .= ')';
			$this->out($out, true);
			return;
		}

		// ![This image][id]
		$link_id = false;
		if (!empty($this->footnotes)) {
			foreach ($this->footnotes as $tag) {
				if ($tag['href'] == $this->parser->tagAttributes['src']
					&& $tag['title'] === $this->parser->tagAttributes['title']
				) {
					$link_id = $tag['linkID'];
					break;
				}
			}
		}
		if (!$link_id) {
			$link_id = count($this->footnotes) + 1;
			$tag = [
				'href' => $this->parser->tagAttributes['src'],
				'linkID' => $link_id,
				'title' => $this->parser->tagAttributes['title']
			];
			array_push($this->footnotes, $tag);
		}
		$out .= '[' . $link_id . ']';

		$this->out($out, true);
	}

	/**
	 * handle <code> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_code()
	{
		if ($this->hasParent('pre')) {
			// ignore code blocks inside <pre>

			return;
		}
		if ($this->parser->isStartTag) {
			$this->buffer();
		} else {
			$buffer = $this->unbuffer();
			// use as many backticks as needed
			preg_match_all('#`+#', $buffer, $matches);
			if (!empty($matches[0])) {
				rsort($matches[0]);

				$ticks = '`';
				while (true) {
					if (!in_array($ticks, $matches[0])) {
						break;
					}
					$ticks .= '`';
				}
			} else {
				$ticks = '`';
			}
			if ($buffer[0] == '`' || substr($buffer, -1) == '`') {
				$buffer = ' ' . $buffer . ' ';
			}
			$this->out($ticks . $buffer . $ticks, true);
		}
	}

	/**
	 * handle <pre> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_pre()
	{
		if ($this->keepHTML && $this->parser->isStartTag) {
			// check if a simple <code> follows
			if (!preg_match('#^\s*<code\s*>#Us', $this->parser->html)) {
				// this is no standard markdown code block
				$this->handleTagToText();

				return;
			}
		}
		$this->indent('    ');
		if (!$this->parser->isStartTag) {
			$this->setLineBreaks(2);
		} else {
			$this->parser->html = ltrim($this->parser->html);
		}
	}

	/**
	 * handle <blockquote> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_blockquote()
	{
		$this->indent('> ');
	}

	/**
	 * handle <ul> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_ul()
	{
		if ($this->parser->isStartTag) {
			$this->stack();
			if (!$this->keepHTML && $this->lastClosedTag == $this->parser->tagName) {
				$this->out("\n" . $this->indent . '<!-- -->' . "\n" . $this->indent . "\n" . $this->indent);
			}
		} else {
			$this->unstack();
			if ($this->parent() != 'li' || preg_match('#^\s*(</li\s*>\s*<li\s*>\s*)?<(p|blockquote)\s*>#sU', $this->parser->html)) {
				// don't make Markdown add unneeded paragraphs
				$this->setLineBreaks(2);
			}
		}
	}

	/**
	 * handle <ol> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_ol()
	{
		// same as above
		$this->parser->tagAttributes['num'] = 0;
		$this->handleTag_ul();
	}

	/**
	 * handle <li> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_li()
	{
		if ($this->parent() == 'ol') {
			$parent =& $this->getStacked('ol');
			if ($this->parser->isStartTag) {
				$parent['num']++;
				$this->out(str_repeat(' ', 3 - strlen($parent['num'])) . $parent['num'] . '. ', true);
			}
		} else {
			if ($this->parser->isStartTag) {
				$this->out('  * ', true);
			}
		}
		$this->indent('    ', false);
		if (!$this->parser->isStartTag) {
			$this->setLineBreaks(1);
		}
	}

	/**
	 * handle <hr /> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_hr()
	{
		if (!$this->parser->isStartTag) {
			return; // just to be sure this really is an empty tag
		}
		$this->out('* * *', true);
		$this->setLineBreaks(2);
	}

	/**
	 * handle <br /> tags
	 *
	 * @param void
	 * @return void
	 */
	protected function handleTag_br()
	{
		// FJ remove two spaces before line break.
		// @link https://github.com/Elephant418/Markdownify/issues/45
		// Will work because $Parsedown->setBreaksEnabled( true ) + marked.setOptions({ breaks: true })
		//$this->out("  \n" . $this->indent, true);
		$this->out("\n" . $this->indent, true);
		$this->parser->html = ltrim($this->parser->html);
	}

	/**
	 * add current node to the stack
	 * this only stores the attributes
	 *
	 * @param void
	 * @return void
	 */
	protected function stack()
	{
		if (!isset($this->stack[$this->parser->tagName])) {
			$this->stack[$this->parser->tagName] = [];
		}
		array_push($this->stack[$this->parser->tagName], $this->parser->tagAttributes);
	}

	/**
	 * remove current tag from stack
	 *
	 * @param void
	 * @return array
	 */
	protected function unstack()
	{
		if (!isset($this->stack[$this->parser->tagName]) || !is_array($this->stack[$this->parser->tagName])) {
			trigger_error('Trying to unstack from empty stack. This must not happen.', E_USER_ERROR);
		}

		return array_pop($this->stack[$this->parser->tagName]);
	}

	/**
	 * get last stacked element of type $tagName
	 *
	 * @param string $tagName
	 * @return array
	 */
	protected function &getStacked($tagName)
	{
		// no end() so it can be referenced
		return $this->stack[$tagName][count($this->stack[$tagName]) - 1];
	}

	/**
	 * set number of line breaks before next start tag
	 *
	 * @param int $number
	 * @return void
	 */
	protected function setLineBreaks($number)
	{
		if ($this->lineBreaks < $number) {
			$this->lineBreaks = $number;
		}
	}

	/**
	 * buffer next parser output until unbuffer() is called
	 *
	 * @param void
	 * @return void
	 */
	protected function buffer()
	{
		array_push($this->buffer, '');
	}

	/**
	 * end current buffer and return buffered output
	 *
	 * @param void
	 * @return string
	 */
	protected function unbuffer()
	{
		return array_pop($this->buffer);
	}

	/**
	 * append string to the correct var, either
	 * directly to $this->output or to the current
	 * buffers
	 *
	 * @param string $put
	 * @param boolean $nowrap
	 * @return void
	 */
	protected function out($put, $nowrap = false)
	{
		if (empty($put)) {
			return;
		}
		if (!empty($this->buffer)) {
			$this->buffer[count($this->buffer) - 1] .= $put;
		} else {
			if ($this->bodyWidth && !$this->parser->keepWhitespace) { // wrap lines
				// get last line
				$pos = strrpos($this->output, "\n");
				if ($pos === false) {
					$line = $this->output;
				} else {
					$line = substr($this->output, $pos);
				}

				if ($nowrap) {
					if ($put[0] != "\n" && $this->strlen($line) + $this->strlen($put) > $this->bodyWidth) {
						$this->output .= "\n" . $this->indent . $put;
					} else {
						$this->output .= $put;
					}

					return;
				} else {
					$put .= "\n"; // make sure we get all lines in the while below
					$lineLen = $this->strlen($line);
					while ($pos = strpos($put, "\n")) {
						$putLine = substr($put, 0, $pos + 1);
						$put = substr($put, $pos + 1);
						$putLen = $this->strlen($putLine);
						if ($lineLen + $putLen < $this->bodyWidth) {
							$this->output .= $putLine;
							$lineLen = $putLen;
						} else {
							$split = preg_split('#^(.{0,' . ($this->bodyWidth - $lineLen) . '})\b#', $putLine, 2, PREG_SPLIT_OFFSET_CAPTURE | PREG_SPLIT_DELIM_CAPTURE);
							$this->output .= rtrim($split[1][0]) . "\n" . $this->indent . $this->wordwrap(ltrim($split[2][0]), $this->bodyWidth, "\n" . $this->indent, false);
						}
					}
					$this->output = substr($this->output, 0, -1);

					return;
				}
			} else {
				$this->output .= $put;
			}
		}
	}

	/**
	 * indent next output (start tag) or unindent (end tag)
	 *
	 * @param string $str indentation
	 * @param bool $output add indendation to output
	 * @return void
	 */
	protected function indent($str, $output = true)
	{
		if ($this->parser->isStartTag) {
			$this->indent .= $str;
			if ($output) {
				$this->out($str, true);
			}
		} else {
			$this->indent = substr($this->indent, 0, -strlen($str));
		}
	}

	/**
	 * decode email addresses
	 *
	 * @author derernst@gmx.ch <http://www.php.net/manual/en/function.html-entity-decode.php#68536>
	 * @author Milian Wolff <http://milianw.de>
	 */
	protected function decode($text, $quote_style = ENT_QUOTES)
	{
		return htmlspecialchars_decode($text, $quote_style);
	}

	/**
	 * callback for decode() which converts a hexadecimal entity to UTF-8
	 *
	 * @param array $matches
	 * @return string UTF-8 encoded
	 */
	protected function _decode_hex($matches)
	{
		return $this->unichr(hexdec($matches[1]));
	}

	/**
	 * callback for decode() which converts a numerical entity to UTF-8
	 *
	 * @param array $matches
	 * @return string UTF-8 encoded
	 */
	protected function _decode_numeric($matches)
	{
		return $this->unichr($matches[1]);
	}

	/**
	 * UTF-8 chr() which supports numeric entities
	 *
	 * @author grey - greywyvern - com <http://www.php.net/manual/en/function.chr.php#55978>
	 * @param array $matches
	 * @return string UTF-8 encoded
	 */
	protected function unichr($dec)
	{
		if ($dec < 128) {
			$utf = chr($dec);
		} elseif ($dec < 2048) {
			$utf = chr(192 + (($dec - ($dec % 64)) / 64));
			$utf .= chr(128 + ($dec % 64));
		} else {
			$utf = chr(224 + (($dec - ($dec % 4096)) / 4096));
			$utf .= chr(128 + ((($dec % 4096) - ($dec % 64)) / 64));
			$utf .= chr(128 + ($dec % 64));
		}

		return $utf;
	}

	/**
	 * UTF-8 strlen()
	 *
	 * @param string $str
	 * @return int
	 *
	 * @author dtorop 932 at hotmail dot com <http://www.php.net/manual/en/function.strlen.php#37975>
	 * @author Milian Wolff <http://milianw.de>
	 */
	protected function strlen($str)
	{
		if (function_exists('mb_strlen')) {
			return mb_strlen($str, 'UTF-8');
		} else {
			return preg_match_all('/[\x00-\x7F\xC0-\xFD]/', $str, $var_empty);
		}
	}

	/**
	 * wordwrap for utf8 encoded strings
	 *
	 * @param string $str
	 * @param integer $len
	 * @param string $what
	 * @return string
	 */
	protected function wordwrap($str, $width, $break, $cut = false)
	{
		if (!$cut) {
			$regexp = '#^(?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){1,' . $width . '}\b#';
		} else {
			$regexp = '#^(?:[\x00-\x7F]|[\xC0-\xFF][\x80-\xBF]+){' . $width . '}#';
		}
		$return = '';
		while (preg_match($regexp, $str, $matches)) {
			$string = $matches[0];
			$str = ltrim(substr($str, strlen($string)));
			if (!$cut && isset($str[0]) && in_array($str[0], ['.', '!', ';', ':', '?', ','])) {
				$string .= $str[0];
				$str = ltrim(substr($str, 1));
			}
			$return .= $string . $break;
		}

		return $return . ltrim($str);
	}

	/**
	 * check if current node has a $tagName as parent (somewhere, not only the direct parent)
	 *
	 * @param string $tagName
	 * @return bool
	 */
	protected function hasParent($tagName)
	{
		return in_array($tagName, $this->parser->openTags);
	}

	/**
	 * get tagName of direct parent tag
	 *
	 * @param void
	 * @return string $tagName
	 */
	protected function parent()
	{
		return end($this->parser->openTags);
	}

	/**
	 * Trims whitespace in block-level elements, on the left side.
	 */
	protected function fixBlockElementSpacing()
	{
		if ($this->parser->isStartTag) {
			$this->parser->html = ltrim($this->parser->html);
		}
	}

	/**
	 * Moves leading/trailing whitespace from inline elements outside of the
	 * element. This is to fix cases like `<strong> Text</strong>`, which if
	 * converted to `** strong**` would be incorrect Markdown.
	 *
	 * Examples:
	 *
	 *   * leading: `<strong> Text</strong>` becomes ` <strong>Text</strong>`
	 *   * trailing: `<strong>Text </strong>` becomes `<strong>Text</strong> `
	 */
	protected function fixInlineElementSpacing()
	{
		if ($this->parser->isStartTag && !$this->parser->isEmptyTag) {
			// move spaces after the start element to before the element
			if (preg_match('~^(\s+)~', $this->parser->html, $matches)) {
				$this->out($matches[1]);
				$this->parser->html = ltrim($this->parser->html, " \t\0\x0B");
			}
		} else {
			if (!empty($this->buffer)) {
				$str =& $this->buffer[count($this->buffer) - 1];
			} else {
				$str =& $this->output;
			}

			// move spaces before the end element to after the element
			if (preg_match('~(\s+)$~', $str, $matches)) {
				$str = rtrim($str, " \t\0\x0B");
				$this->parser->html = $matches[1] . $this->parser->html;
			}
		}
	}

	/**
	 * Resetting the state forces the instance to behave as a fresh instance.
	 * Ideal for running within a loop where you want to maintain a single instance.
	 */
	protected function resetState()
	{
		$this->notConverted = [];
		$this->skipConversion = false;
		$this->buffer = [];
		$this->indent = '';
		$this->stack = [];
		$this->lineBreaks = 0;
		$this->lastClosedTag = '';
		$this->lastWasBlockTag = false;
		$this->footnotes = [];
	}
}
