<?php

## PhpPatcher class

# @author legolas558

# @version 0.1.1

# Licensed under GNU General Public License (GPL)

#

# Facility to merge unified diff files

# First use Merge() and then ApplyPatch() to commit changes

# files will be created, updated and/or deleted



define('_PHPP_INVALID_INPUT', 'Invalid input');

define('_PHPP_UNEXPECTED_EOF', 'Unexpected end of file');

define('_PHPP_UNEXPECTED_ADD_LINE', 'Unexpected add line at line %d');

define('_PHPP_UNEXPECTED_REMOVE_LINE', 'Unexpected remove line at line %d');

define('_PHPP_INVALID_DIFF', 'Invalid unified diff block');

define('_PHPP_FAILED_VERIFY', 'Failed source verification of file %s at line %d');



class _patch {

	var $root;

	var $msg;

	var $sources = array();

	var $destinations = array();

	var $removals = array();

	var $newline = "\n";

	

	function __construct($root_path) {

		// if you specify a root path all paths will be intended as relative to it (and not written, too)

		$this->root = $root_path;

	}

	

	function &_get_source($src) {

		if (isset($this->sources[$src]))

			return $this->sources[$src];

		if (!is_readable($src)) {

			$n = null;

			return $n;

		}

		$this->sources[$src] = $this->_linesplit(file_get_contents($src));

		return $this->sources[$src];

	}

	

	function &_get_destin($dst, $src) {

		if (isset($this->destinations[$dst]))

			return $this->destinations[$dst];

		$this->destinations[$dst] = $this->_get_source($src);

		return $this->destinations[$dst];

	}



	// separate CR or CRLF lines

	function &_linesplit(&$data) {

		$lines = preg_split('/(\r\n)|(\r)|(\n)/', $data);

		return $lines;

	}

	

	function merge($udiff) {

		// (1) Separate the input into lines

		$lines = $this->_linesplit($udiff);

		if (!isset($lines)) {

			$this->msg = _PHPP_INVALID_INPUT;

			return false;

		}

		unset($udiff);

	

		$line = current($lines);

		do {

			if (strlen($line)<5)

				continue;

			// start recognition when a new diff block is found

			if (substr($line, 0, 4)!='--- ')

				continue;

			$p = strpos($line, "\t", 4);

			if ($p===false)	$p = strlen($line);

			$src = $this->root.substr($line, 4, $p-4);

			$line = next($lines);

			if (!isset($line)) {

				$this->msg = _PHPP_UNEXPECTED_EOF;

				return false;

			}

			if (substr($line, 0, 4)!='+++ ') {

				$this->msg = _PHPP_INVALID_DIFF;

				return false;

			}

			$p = strpos($line, "\t", 4);

			if ($p===false)	$p = strlen($line);

			$dst = $this->root.substr($line, 4, $p-4);

			

			$line = next($lines);

			if (!isset($line)) {

				$this->msg = _PHPP_UNEXPECTED_EOF;

				return false;

			}

			

			$done=0;

			while (preg_match('/@@ -(\\d+)(,(\\d+))?\\s+\\+(\\d+)(,(\\d+))?\\s+@@($)/A', $line, $m)) {

			

				if ($m[3]==='')

					$src_size = 1;

				else $src_size = (int)$m[3];

				if ($m[6]==='')

					$dst_size = 1;

				else $dst_size = (int)$m[6];

				if (!$this->_apply_diff($lines, $src, $dst,

									(int)$m[1], $src_size, (int)$m[4],

									$dst_size))

					return false;

				$done++;

				$line = next($lines);

				if ($line === FALSE)

					break 2;

			}

			if ($done==0) {

				$this->msg = _PHPP_INVALID_DIFF;

				return false;

			}

			

		} while (FALSE !== ($line = next($lines)));

		

		//NOTE: previously opened files are still cached

		return true;

	}

	

	function clearCache() {

		$this->sources = array();

		$this->destinations = array();

		$this->removals = array();

	}

	

	function applyPatch() {

		if (empty($this->destinations))

			return 0;

		$done = 0;

		$files = array_keys($this->destinations);

		foreach($files as $file) {

			$f = @fopen($file, 'w');

			if ($f===null)

				continue;

			fwrite($f, implode($this->newline, $this->destinations[$file]));

			fclose($f);

			$done++;

		}

		foreach($this->removals as $file) {

			if (@unlink($file))

				$done++;

			if (isset($this->sources[$file]))

				unset($this->sources[$file]);

		}

		$this->destinations = array(); // clear the destinations cache

		$this->removals = array();

		return $done;

	}

	

	function _apply_diff(&$lines, $src, $dst, $src_line, $src_size, $dst_line, $dst_size) {

		$src_line--;

		$dst_line--;

		$line = next($lines);

		if ($line === false) {

			$this->msg = _PHPP_UNEXPECTED_EOF;

			return false;

		}

		$source = array();		// source lines (old file)

		$destin = array();		// new lines (new file)

		$src_left = $src_size;

		$dst_left = $dst_size;

		do {

			if (!isset($line{0})) {

				$source[] = '';

				$destin[] = '';

				$src_left--;

				$dst_left--;

				continue;

			}

			if ($line{0}=='-') {

				if ($src_left==0) {

					$this->msg = sprintf(_PHPP_UNEXPECTED_REMOVE_LINE, key($lines));

					return false;

				}

				$source[] = substr($line, 1);

				$src_left--;

			} else if ($line{0}=='+') {

				if ($dst_left==0) {

					$this->msg = sprintf(_PHPP_UNEXPECTED_ADD_LINE, key($lines));

					return false;

				}

				$destin[] = substr($line, 1);

				$dst_left--;

			} else {

				if (!isset($line{1}))

					$line = '';

				else if ($line{0}=='\\') {

					if ($line=='\\ No newline at end of file')

						continue;

				} else

					$line = substr($line, 1);

				$source[] = $line;

				$destin[] = $line;

				$src_left--;

				$dst_left--;

			}

			

			if (($src_left==0) && ($dst_left==0)) {

				// now apply the patch, finally!

				if ($src_size>0) {

					$src_lines =& $this->_get_source($src);

					if (!isset($src_lines))

						return false;

				}

				if ($dst_size>0) {

					if ($src_size>0) {

						$dst_lines =& $this->_get_destin($dst, $src);

						if (!isset($dst_lines))

							return false;

						$src_bottom=$src_line+count($source);

						$dst_bottom=$dst_line+count($destin);

						

						for ($l=$src_line;$l<$src_bottom;$l++) {

							if ($src_lines[$l]!=$source[$l-$src_line]) {

								$this->msg = sprintf(_PHPP_FAILED_VERIFY, $src, $l);

								return false;

							}

						}

						array_splice($dst_lines, $dst_line, count($source), $destin);

					} else

						$this->destinations[$dst] = $destin;

				} else

					$this->removals[] = $src;

				

				return true;

			}

		} while (FALSE !== ($line = next($lines)));



		$this->msg = _PHPP_UNEXPECTED_EOF;

		return false;

	}

	

	function diff(&$latest, &$udiff) {

		$this->msg = 'Not available';

		return false;

	}



}



?>