<?php
/***************************************************************
*  Copyright notice
*
*  (c) 1999-2006 Kasper Skaarhoj (kasperYYYY@typo3.com)
*  All rights reserved
*
*  This script is part of the TYPO3 project. The TYPO3 project is
*  free software; you can redistribute it and/or modify
*  it under the terms of the GNU General Public License as published by
*  the Free Software Foundation; either version 2 of the License, or
*  (at your option) any later version.
*
*  The GNU General Public License can be found at
*  http://www.gnu.org/copyleft/gpl.html.
*  A copy is found in the textfile GPL.txt and important notices to the license
*  from the author is found in LICENSE.txt distributed with these scripts.
*
*
*  This script is distributed in the hope that it will be useful,
*  but WITHOUT ANY WARRANTY; without even the implied warranty of
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*  GNU General Public License for more details.
*
*  This copyright notice MUST APPEAR in all copies of the script!
***************************************************************/
/**
 * Contains class which has functions that generates a difference output of a content string
 *
 * $Id$
 * Revised for TYPO3 3.6 November/2003 by Kasper Skaarhoj
 * XHTML Compliant
 *
 * @author	Kasper Skaarhoj <kasperYYYY@typo3.com>
 */
/**
 * [CLASS/FUNCTION INDEX of SCRIPT]
 *
 *
 *
 *   66: class t3lib_diff
 *   86:     function makeDiffDisplay($str1,$str2,$wrapTag='span')
 *  163:     function getDiff($str1,$str2)
 *  189:     function addClearBuffer($clearBuffer,$last=0)
 *  205:     function explodeStringIntoWords($str)
 *  226:     function tagSpace($str,$rev=0)
 *
 * TOTAL FUNCTIONS: 5
 * (This index is automatically created/updated by the extension "extdeveval")
 *
 */


/**
 * This class has functions which generates a difference output of a content string
 *
 * @author	Kasper Skaarhoj <kasperYYYY@typo3.com>
 * @package TYPO3
 * @subpackage t3lib
 */
class t3lib_diff {

		// External, static:
	var $stripTags = 0;			// If set, the HTML tags are stripped from the input strings first.
	var $diffOptions = '';		// Diff options. eg "--unified=3"

		// Internal, dynamic:
	var $clearBufferIdx=0;		// This indicates the number of times the function addClearBuffer has been called - and used to detect the very first call...
	var $differenceLgd=0;


	/**
	 * This will produce a color-marked-up diff output in HTML from the input strings.
	 *
	 * @param	string		String 1
	 * @param	string		String 2
	 * @param	string		Setting the wrapping tag name
	 * @return	string		Formatted output.
	 */
	function makeDiffDisplay($str1,$str2,$wrapTag='span')	{
		if ($this->stripTags)	{
			$str1 = strip_tags($str1);
			$str2 = strip_tags($str2);
		} else {
			$str1 = $this->tagSpace($str1);
			$str2 = $this->tagSpace($str2);
		}
		$str1Lines = $this->explodeStringIntoWords($str1);
		$str2Lines = $this->explodeStringIntoWords($str2);

		$diffRes = $this->getDiff(implode(chr(10),$str1Lines).chr(10),implode(chr(10),$str2Lines).chr(10));

		if (is_array($diffRes))	{
			reset($diffRes);
			$c=0;
			$diffResArray=array();
			$differenceStr = '';
			while(list(,$lValue)=each($diffRes))	{
				if (intval($lValue))	{
					$c=intval($lValue);
					$diffResArray[$c]['changeInfo']=$lValue;
				}
				if (substr($lValue,0,1)=='<')	{
					$differenceStr.= $diffResArray[$c]['old'][] = substr($lValue,2);
				}
				if (substr($lValue,0,1)=='>')	{
					$differenceStr.= $diffResArray[$c]['new'][] = substr($lValue,2);
				}
			}

			$this->differenceLgd = strlen($differenceStr);

			$outString='';
			$clearBuffer='';
			for ($a=-1;$a<count($str1Lines);$a++)	{
				if (is_array($diffResArray[$a+1]))	{
					if (strstr($diffResArray[$a+1]['changeInfo'],'a'))	{	// a=Add, c=change, d=delete: If a, then the content is Added after the entry and we must insert the line content as well.
						$clearBuffer.=htmlspecialchars($str1Lines[$a]).' ';
					}

					$outString.=$this->addClearBuffer($clearBuffer);
					$clearBuffer='';
					if (is_array($diffResArray[$a+1]['old']))	{
						$outString.='<'.$wrapTag.' class="diff-r">'.htmlspecialchars(implode(' ',$diffResArray[$a+1]['old'])).'</'.$wrapTag.'> ';
					}
					if (is_array($diffResArray[$a+1]['new']))	{
						$outString.='<'.$wrapTag.' class="diff-g">'.htmlspecialchars(implode(' ',$diffResArray[$a+1]['new'])).'</'.$wrapTag.'> ';
					}
					$chInfParts = explode(',',$diffResArray[$a+1]['changeInfo']);
					if (!strcmp($chInfParts[0],$a+1))	{
						$newLine = intval($chInfParts[1])-1;
						if ($newLine>$a)	$a=$newLine;	// Security that $a is not set lower than current for some reason...
					}
				} else {
					$clearBuffer.=htmlspecialchars($str1Lines[$a]).' ';
				}
			}
			$outString.=$this->addClearBuffer($clearBuffer,1);

			$outString = str_replace('  ',chr(10),$outString);
			if (!$this->stripTags)	{
				$outString = $this->tagSpace($outString,1);
			}
			return $outString;
		}
	}

	/**
	 * Produce a diff (using the "diff" application) between two strings
	 * The function will write the two input strings to temporary files, then execute the diff program, delete the temp files and return the result.
	 *
	 * @param	string		String 1
	 * @param	string		String 2
	 * @return	array		The result from the exec() function call.
	 * @access private
	 */
	function getDiff($str1,$str2)	{
			// Create file 1 and write string
		$file1 = t3lib_div::tempnam('diff1_');
		t3lib_div::writeFile($file1,$str1);
			// Create file 2 and write string
		$file2 = t3lib_div::tempnam('diff2_');
		t3lib_div::writeFile($file2,$str2);
			// Perform diff.
		$cmd = $GLOBALS['TYPO3_CONF_VARS']['BE']['diff_path'].' '.$this->diffOptions.' '.$file1.' '.$file2;
		$res = array();
		exec($cmd,$res);

		unlink($file1);
		unlink($file2);

		return $res;
	}

	/**
	 * Will bring down the length of strings to < 150 chars if they were longer than 200 chars. This done by preserving the 70 first and last chars and concatenate those strings with "..." and a number indicating the string length
	 *
	 * @param	string		The input string.
	 * @param	boolean		If set, it indicates that the string should just end with ... (thus no "complete" ending)
	 * @return	string		Processed string.
	 * @access private
	 */
	function addClearBuffer($clearBuffer,$last=0)	{
		if (strlen($clearBuffer)>200)	{
			$clearBuffer=($this->clearBufferIdx?t3lib_div::fixed_lgd_cs($clearBuffer,70):'').'['.strlen($clearBuffer).']'.(!$last?t3lib_div::fixed_lgd_cs($clearBuffer,-70):'');
		}
		$this->clearBufferIdx++;
		return $clearBuffer;
	}

	/**
	 * Explodes the input string into words.
	 * This is done by splitting first by lines, then by space char. Each word will be in stored as a value in an array. Lines will be indicated by two subsequent empty values.
	 *
	 * @param	string		The string input
	 * @return	array		Array with words.
	 * @access private
	 */
	function explodeStringIntoWords($str)	{
		$strArr = t3lib_div::trimExplode(chr(10),$str);
		$outArray=array();
		reset($strArr);
		while(list(,$lineOfWords)=each($strArr))	{
			$allWords = t3lib_div::trimExplode(' ',$lineOfWords,1);
			$outArray = array_merge($outArray,$allWords);
			$outArray[]='';
			$outArray[]='';
		}
		return $outArray;
	}

	/**
	 * Adds a space character before and after HTML tags (more precisely any found < or >)
	 *
	 * @param	string		String to process
	 * @param	boolean		If set, the < > searched for will be &lt; and &gt;
	 * @return	string		Processed string
	 * @access private
	 */
	function tagSpace($str,$rev=0)	{
		if ($rev)	{
			return str_replace(' &lt;','&lt;',str_replace('&gt; ','&gt;',$str));
		} else {
			return str_replace('<',' <',str_replace('>','> ',$str));
		}
	}
}

if (defined('TYPO3_MODE') && $TYPO3_CONF_VARS[TYPO3_MODE]['XCLASS']['t3lib/class.t3lib_diff.php'])	{
	include_once($TYPO3_CONF_VARS[TYPO3_MODE]['XCLASS']['t3lib/class.t3lib_diff.php']);
}
?>