<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');

/**

 * CodeIgniter

 *

 * An open source application development framework for PHP 5.1.6 or newer

 *

 * @package		CodeIgniter

 * @author		ExpressionEngine Dev Team

 * @copyright	Copyright (c) 2008 - 2011, EllisLab, Inc.

 * @license		http://codeigniter.com/user_guide/license.html

 * @link		http://codeigniter.com

 * @since		Version 1.0

 * @filesource

 */



// ------------------------------------------------------------------------



/**

 * Typography Class

 *

 *

 * @access		private

 * @category	Helpers

 * @author		ExpressionEngine Dev Team

 * @link		http://codeigniter.com/user_guide/helpers/

 */

class CI_Typography {



	// Block level elements that should not be wrapped inside <p> tags

	var $block_elements = 'address|blockquote|div|dl|fieldset|form|h\d|hr|noscript|object|ol|p|pre|script|table|ul';



	// Elements that should not have <p> and <br /> tags within them.

	var $skip_elements	= 'p|pre|ol|ul|dl|object|table|h\d';



	// Tags we want the parser to completely ignore when splitting the string.

	var $inline_elements = 'a|abbr|acronym|b|bdo|big|br|button|cite|code|del|dfn|em|i|img|ins|input|label|map|kbd|q|samp|select|small|span|strong|sub|sup|textarea|tt|var';



	// array of block level elements that require inner content to be within another block level element

	var $inner_block_required = array('blockquote');



	// the last block element parsed

	var $last_block_element = '';



	// whether or not to protect quotes within { curly braces }

	var $protect_braced_quotes = FALSE;



	/**

	 * Auto Typography

	 *

	 * This function converts text, making it typographically correct:

	 *	- Converts double spaces into paragraphs.

	 *	- Converts single line breaks into <br /> tags

	 *	- Converts single and double quotes into correctly facing curly quote entities.

	 *	- Converts three dots into ellipsis.

	 *	- Converts double dashes into em-dashes.

	 *  - Converts two spaces into entities

	 *

	 * @access	public

	 * @param	string

	 * @param	bool	whether to reduce more then two consecutive newlines to two

	 * @return	string

	 */

	function auto_typography($str, $reduce_linebreaks = FALSE)

	{

		if ($str == '')

		{

			return '';

		}



		// Standardize Newlines to make matching easier

		if (strpos($str, "\r") !== FALSE)

		{

			$str = str_replace(array("\r\n", "\r"), "\n", $str);

		}



		// Reduce line breaks.  If there are more than two consecutive linebreaks

		// we'll compress them down to a maximum of two since there's no benefit to more.

		if ($reduce_linebreaks === TRUE)

		{

			$str = preg_replace("/\n\n+/", "\n\n", $str);

		}



		// HTML comment tags don't conform to patterns of normal tags, so pull them out separately, only if needed

		$html_comments = array();

		if (strpos($str, '<!--') !== FALSE)

		{

			if (preg_match_all("#(<!\-\-.*?\-\->)#s", $str, $matches))

			{

				for ($i = 0, $total = count($matches[0]); $i < $total; $i++)

				{

					$html_comments[] = $matches[0][$i];

					$str = str_replace($matches[0][$i], '{@HC'.$i.'}', $str);

				}

			}

		}



		// match and yank <pre> tags if they exist.  It's cheaper to do this separately since most content will

		// not contain <pre> tags, and it keeps the PCRE patterns below simpler and faster

		if (strpos($str, '<pre') !== FALSE)

		{

			$str = preg_replace_callback("#<pre.*?>.*?</pre>#si", array($this, '_protect_characters'), $str);

		}



		// Convert quotes within tags to temporary markers.

		$str = preg_replace_callback("#<.+?>#si", array($this, '_protect_characters'), $str);



		// Do the same with braces if necessary

		if ($this->protect_braced_quotes === TRUE)

		{

			$str = preg_replace_callback("#\{.+?\}#si", array($this, '_protect_characters'), $str);

		}



		// Convert "ignore" tags to temporary marker.  The parser splits out the string at every tag

		// it encounters.  Certain inline tags, like image tags, links, span tags, etc. will be

		// adversely affected if they are split out so we'll convert the opening bracket < temporarily to: {@TAG}

		$str = preg_replace("#<(/*)(".$this->inline_elements.")([ >])#i", "{@TAG}\\1\\2\\3", $str);



		// Split the string at every tag.  This expression creates an array with this prototype:

		//

		//	[array]

		//	{

		//		[0] = <opening tag>

		//		[1] = Content...

		//		[2] = <closing tag>

		//		Etc...

		//	}

		$chunks = preg_split('/(<(?:[^<>]+(?:"[^"]*"|\'[^\']*\')?)+>)/', $str, -1, PREG_SPLIT_DELIM_CAPTURE|PREG_SPLIT_NO_EMPTY);



		// Build our finalized string.  We cycle through the array, skipping tags, and processing the contained text

		$str = '';

		$process = TRUE;

		$paragraph = FALSE;

		$current_chunk = 0;

		$total_chunks = count($chunks);



		foreach ($chunks as $chunk)

		{

			$current_chunk++;



			// Are we dealing with a tag? If so, we'll skip the processing for this cycle.

			// Well also set the "process" flag which allows us to skip <pre> tags and a few other things.

			if (preg_match("#<(/*)(".$this->block_elements.").*?>#", $chunk, $match))

			{

				if (preg_match("#".$this->skip_elements."#", $match[2]))

				{

					$process =  ($match[1] == '/') ? TRUE : FALSE;

				}



				if ($match[1] == '')

				{

					$this->last_block_element = $match[2];

				}



				$str .= $chunk;

				continue;

			}



			if ($process == FALSE)

			{

				$str .= $chunk;

				continue;

			}



			//  Force a newline to make sure end tags get processed by _format_newlines()

			if ($current_chunk == $total_chunks)

			{

				$chunk .= "\n";

			}



			//  Convert Newlines into <p> and <br /> tags

			$str .= $this->_format_newlines($chunk);

		}



		// No opening block level tag?  Add it if needed.

		if ( ! preg_match("/^\s*<(?:".$this->block_elements.")/i", $str))

		{

			$str = preg_replace("/^(.*?)<(".$this->block_elements.")/i", '<p>$1</p><$2', $str);

		}



		// Convert quotes, elipsis, em-dashes, non-breaking spaces, and ampersands

		$str = $this->format_characters($str);



		// restore HTML comments

		for ($i = 0, $total = count($html_comments); $i < $total; $i++)

		{

			// remove surrounding paragraph tags, but only if there's an opening paragraph tag

			// otherwise HTML comments at the ends of paragraphs will have the closing tag removed

			// if '<p>{@HC1}' then replace <p>{@HC1}</p> with the comment, else replace only {@HC1} with the comment

			$str = preg_replace('#(?(?=<p>\{@HC'.$i.'\})<p>\{@HC'.$i.'\}(\s*</p>)|\{@HC'.$i.'\})#s', $html_comments[$i], $str);

		}



		// Final clean up

		$table = array(



						// If the user submitted their own paragraph tags within the text

						// we will retain them instead of using our tags.

						'/(<p[^>*?]>)<p>/'	=> '$1', // <?php BBEdit syntax coloring bug fix



						// Reduce multiple instances of opening/closing paragraph tags to a single one

						'#(</p>)+#'			=> '</p>',

						'/(<p>\W*<p>)+/'	=> '<p>',



						// Clean up stray paragraph tags that appear before block level elements

						'#<p></p><('.$this->block_elements.')#'	=> '<$1',



						// Clean up stray non-breaking spaces preceeding block elements

						'#(&nbsp;\s*)+<('.$this->block_elements.')#'	=> '  <$2',



						// Replace the temporary markers we added earlier

						'/\{@TAG\}/'		=> '<',

						'/\{@DQ\}/'			=> '"',

						'/\{@SQ\}/'			=> "'",

						'/\{@DD\}/'			=> '--',

						'/\{@NBS\}/'		=> '  ',



						// An unintended consequence of the _format_newlines function is that

						// some of the newlines get truncated, resulting in <p> tags

						// starting immediately after <block> tags on the same line.

						// This forces a newline after such occurrences, which looks much nicer.

						"/><p>\n/"			=> ">\n<p>",



						// Similarly, there might be cases where a closing </block> will follow

						// a closing </p> tag, so we'll correct it by adding a newline in between

						"#</p></#"			=> "</p>\n</"

						);



		// Do we need to reduce empty lines?

		if ($reduce_linebreaks === TRUE)

		{

			$table['#<p>\n*</p>#'] = '';

		}

		else

		{

			// If we have empty paragraph tags we add a non-breaking space

			// otherwise most browsers won't treat them as true paragraphs

			$table['#<p></p>#'] = '<p>&nbsp;</p>';

		}



		return preg_replace(array_keys($table), $table, $str);



	}



	// --------------------------------------------------------------------



	/**

	 * Format Characters

	 *

	 * This function mainly converts double and single quotes

	 * to curly entities, but it also converts em-dashes,

	 * double spaces, and ampersands

	 *

	 * @access	public

	 * @param	string

	 * @return	string

	 */

	function format_characters($str)

	{

		static $table;



		if ( ! isset($table))

		{

			$table = array(

							// nested smart quotes, opening and closing

							// note that rules for grammar (English) allow only for two levels deep

							// and that single quotes are _supposed_ to always be on the outside

							// but we'll accommodate both

							// Note that in all cases, whitespace is the primary determining factor

							// on which direction to curl, with non-word characters like punctuation

							// being a secondary factor only after whitespace is addressed.

							'/\'"(\s|$)/'					=> '&#8217;&#8221;$1',

							'/(^|\s|<p>)\'"/'				=> '$1&#8216;&#8220;',

							'/\'"(\W)/'						=> '&#8217;&#8221;$1',

							'/(\W)\'"/'						=> '$1&#8216;&#8220;',

							'/"\'(\s|$)/'					=> '&#8221;&#8217;$1',

							'/(^|\s|<p>)"\'/'				=> '$1&#8220;&#8216;',

							'/"\'(\W)/'						=> '&#8221;&#8217;$1',

							'/(\W)"\'/'						=> '$1&#8220;&#8216;',



							// single quote smart quotes

							'/\'(\s|$)/'					=> '&#8217;$1',

							'/(^|\s|<p>)\'/'				=> '$1&#8216;',

							'/\'(\W)/'						=> '&#8217;$1',

							'/(\W)\'/'						=> '$1&#8216;',



							// double quote smart quotes

							'/"(\s|$)/'						=> '&#8221;$1',

							'/(^|\s|<p>)"/'					=> '$1&#8220;',

							'/"(\W)/'						=> '&#8221;$1',

							'/(\W)"/'						=> '$1&#8220;',



							// apostrophes

							"/(\w)'(\w)/"					=> '$1&#8217;$2',



							// Em dash and ellipses dots

							'/\s?\-\-\s?/'					=> '&#8212;',

							'/(\w)\.{3}/'					=> '$1&#8230;',



							// double space after sentences

							'/(\W)  /'						=> '$1&nbsp; ',



							// ampersands, if not a character entity

							'/&(?!#?[a-zA-Z0-9]{2,};)/'		=> '&amp;'

						);

		}



		return preg_replace(array_keys($table), $table, $str);

	}



	// --------------------------------------------------------------------



	/**

	 * Format Newlines

	 *

	 * Converts newline characters into either <p> tags or <br />

	 *

	 * @access	public

	 * @param	string

	 * @return	string

	 */

	function _format_newlines($str)

	{

		if ($str == '')

		{

			return $str;

		}



		if (strpos($str, "\n") === FALSE  && ! in_array($this->last_block_element, $this->inner_block_required))

		{

			return $str;

		}



		// Convert two consecutive newlines to paragraphs

		$str = str_replace("\n\n", "</p>\n\n<p>", $str);



		// Convert single spaces to <br /> tags

		$str = preg_replace("/([^\n])(\n)([^\n])/", "\\1<br />\\2\\3", $str);



		// Wrap the whole enchilada in enclosing paragraphs

		if ($str != "\n")

		{

			// We trim off the right-side new line so that the closing </p> tag

			// will be positioned immediately following the string, matching

			// the behavior of the opening <p> tag

			$str =  '<p>'.rtrim($str).'</p>';

		}



		// Remove empty paragraphs if they are on the first line, as this

		// is a potential unintended consequence of the previous code

		$str = preg_replace("/<p><\/p>(.*)/", "\\1", $str, 1);



		return $str;

	}



	// ------------------------------------------------------------------------



	/**

	 * Protect Characters

	 *

	 * Protects special characters from being formatted later

	 * We don't want quotes converted within tags so we'll temporarily convert them to {@DQ} and {@SQ}

	 * and we don't want double dashes converted to emdash entities, so they are marked with {@DD}

	 * likewise double spaces are converted to {@NBS} to prevent entity conversion

	 *

	 * @access	public

	 * @param	array

	 * @return	string

	 */

	function _protect_characters($match)

	{

		return str_replace(array("'",'"','--','  '), array('{@SQ}', '{@DQ}', '{@DD}', '{@NBS}'), $match[0]);

	}



	// --------------------------------------------------------------------



	/**

	 * Convert newlines to HTML line breaks except within PRE tags

	 *

	 * @access	public

	 * @param	string

	 * @return	string

	 */

	function nl2br_except_pre($str)

	{

		$ex = explode("pre>",$str);

		$ct = count($ex);



		$newstr = "";

		for ($i = 0; $i < $ct; $i++)

		{

			if (($i % 2) == 0)

			{

				$newstr .= nl2br($ex[$i]);

			}

			else

			{

				$newstr .= $ex[$i];

			}



			if ($ct - 1 != $i)

				$newstr .= "pre>";

		}



		return $newstr;

	}



}

// END Typography Class



/* End of file Typography.php */

/* Location: ./system/libraries/Typography.php */