<?php
// WebSVN - Subversion repository viewing via the web using PHP
// Copyright (C) 2004-2006 Tim Armes
//
// This program 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.
//
// This program 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.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
//
// --
//
// comp.php
//
// Compare two paths using `svn diff`
//

require_once 'include/setup.php';
require_once 'include/svnlook.php';
require_once 'include/utils.php';
require_once 'include/template.php';

function checkRevision($rev) 
{
	if (is_numeric($rev) && ((int)$rev > 0)) 
	{
		return $rev;
	}
	return 'HEAD';
}

// Make sure that we have a repository
if (!$rep)
{
	renderTemplate404('compare','NOREP');
}

$svnrep = new SVNRepository($rep);

// Retrieve the request information
$path1 = @$_REQUEST['compare'][0];
$path2 = @$_REQUEST['compare'][1];
$rev1 = (int)@$_REQUEST['compare_rev'][0];
$rev2 = (int)@$_REQUEST['compare_rev'][1];
$manualorder = (@$_REQUEST['manualorder'] == 1);
$ignoreWhitespace = $config->getIgnoreWhitespacesInDiff();

if (array_key_exists('ignorews', $_REQUEST)) 
{
	$ignoreWhitespace = (bool)$_REQUEST['ignorews'];
}

// Some page links put the revision with the path...
if (strpos($path1, '@')) 
{
	list($path1, $rev1) = explode('@', $path1);
}
else if (strpos($path1, '@') === 0) 
{
	// Something went wrong. The path is missing.
	$rev1 = substr($path1, 1);
	$path1 = '/';
}

if (strpos($path2, '@')) 
{
	list($path2, $rev2) = explode('@', $path2);
}
else if (strpos($path2, '@') === 0) 
{
	$rev2 = substr($path2, 1);
	$path2 = '/';
}

$rev1 = checkRevision($rev1);
$rev2 = checkRevision($rev2);

// Choose a sensible comparison order unless told not to

if (!$manualorder && is_numeric($rev1) && is_numeric($rev2) && $rev1 > $rev2) 
{
	$temppath = $path1;
	$path1 = $path2;
	$path2 = $temppath;

	$temprev = $rev1;
	$rev1 = $rev2;
	$rev2 = $temprev;
}

$vars['rev1url'] = $config->getURL($rep, $path1, 'dir').createRevAndPegString($rev1, $rev1);
$vars['rev2url'] = $config->getURL($rep, $path2, 'dir').createRevAndPegString($rev2, $rev2);

$url = $config->getURL($rep, '', 'comp');
$vars['reverselink'] = '<a href="'.$url.'compare%5B%5D='.urlencode($path2).'@'.$rev2.'&amp;compare%5B%5D='.urlencode($path1).'@'.$rev1.'&amp;manualorder=1'.($ignoreWhitespace ? '&amp;ignorews=1' : '').'">'.$lang['REVCOMP'].'</a>';
$toggleIgnoreWhitespace = '';

if ($ignoreWhitespace == $config->getIgnoreWhitespacesInDiff()) 
{
	$toggleIgnoreWhitespace = '&amp;ignorews='.($ignoreWhitespace ? '0' : '1');
}

if (!$ignoreWhitespace) 
{
	$vars['ignorewhitespacelink'] = '<a href="'.$url.'compare%5B%5D='.urlencode($path1).'@'.$rev1.'&amp;compare%5B%5D='.urlencode($path2).'@'.$rev2.($manualorder ? '&amp;manualorder=1' : '').$toggleIgnoreWhitespace.'">'.$lang['IGNOREWHITESPACE'].'</a>';
}
else 
{
	$vars['regardwhitespacelink'] = '<a href="'.$url.'compare%5B%5D='.urlencode($path1).'@'.$rev1.'&amp;compare%5B%5D='.urlencode($path2).'@'.$rev2.($manualorder ? '&amp;manualorder=1' : '').$toggleIgnoreWhitespace.'">'.$lang['REGARDWHITESPACE'].'</a>';
}

if ($rev1 == 0) $rev1 = 'HEAD';
if ($rev2 == 0) $rev2 = 'HEAD';

$vars['repname'] = escape($rep->getDisplayName());
$vars['action'] = $lang['PATHCOMPARISON'];

$hidden = '<input type="hidden" name="manualorder" value="1" />';

if ($config->multiViews) 
{
	$hidden .= '<input type="hidden" name="op" value="comp"/>';
}
else
{
	$hidden .= '<input type="hidden" name="repname" value="'.$repname.'" />';
}

$vars['compare_form'] = '<form method="get" action="'.$url.'" id="compare">'.$hidden;
$vars['compare_path1input'] = '<input type="text" size="40" name="compare[0]" value="'.escape($path1).'" />';
$vars['compare_path2input'] = '<input type="text" size="40" name="compare[1]" value="'.escape($path2).'" />';
$vars['compare_rev1input'] = '<input type="text" size="5" name="compare_rev[0]" value="'.$rev1.'" />';
$vars['compare_rev2input'] = '<input type="text" size="5" name="compare_rev[1]" value="'.$rev2.'" />';
$vars['compare_submit'] = '<input name="comparesubmit" type="submit" value="'.$lang['COMPAREPATHS'].'" />';
$vars['compare_endform'] = '</form>';

// safe paths are a hack for fixing XSS exploit
$vars['path1'] = escape($path1);
$vars['safepath1'] = escape($path1);
$vars['path2'] = escape($path2);
$vars['safepath2'] = escape($path2);

$vars['rev1'] = $rev1;
$vars['rev2'] = $rev2;

$history1 = $svnrep->getLog($path1, $rev1, 0, false, 1);
if (!$history1) 
{
	renderTemplate404('compare','NOPATH');
}
else
{
	$history2 = $svnrep->getLog($path2, $rev2, 0, false, 1);

	if (!$history2) 
	{
		renderTemplate404('compare','NOPATH');
	}
}

// Set variables used for the more recent of the two revisions
$history = ($rev1 >= $rev2 ? $history1 : $history2);
if ($history && $history->curEntry) 
{
	$logEntry = $history->curEntry;
	$vars['rev'] = $logEntry->rev;
	$vars['peg'] = $peg;
	$vars['date'] = $logEntry->date;
	$vars['age'] = datetimeFormatDuration(time() - strtotime($logEntry->date));
	$vars['author'] = $logEntry->author;
	$vars['log'] = xml_entities($logEntry->msg);
}
else
{
	$vars['warning'] = 'Problem with comparison.';
}

$noinput = empty($path1) || empty($path2);

// Generate the diff listing

$relativePath1 = $path1;
$relativePath2 = $path2;

$svnpath1 = encodepath($svnrep->getSvnPath(str_replace(DIRECTORY_SEPARATOR, '/', $path1)));
$svnpath2 = encodepath($svnrep->getSvnPath(str_replace(DIRECTORY_SEPARATOR, '/', $path2)));

$debug = false;

if (!$noinput) 
{
	$cmd = $config->getSvnCommand().$rep->svnCredentials().' diff '.($ignoreWhitespace ? '-x "-w --ignore-eol-style" ' : '').quote($svnpath1.'@'.$rev1).' '.quote($svnpath2.'@'.$rev2);
}

function clearVars() 
{
	global $ignoreWhitespace, $listing, $index;

	if ($ignoreWhitespace && $index > 1) 
	{
		$endBlock = false;
		$previous = $index - 1;
		if ($listing[$previous]['endpath']) $endBlock = 'newpath';
		else if ($listing[$previous]['enddifflines']) $endBlock = 'difflines';

		if ($endBlock !== false) 
		{
			// check if block ending at previous contains real diff data
			$i = $previous;
			$containsOnlyEqualDiff = true;
			$addedLines = array();
			$removedLines = array();
			while ($i >= 0 && !$listing[$i - 1][$endBlock]) 
			{
				$diffclass = $listing[$i - 1]['diffclass'];

				if ($diffclass !== 'diffadded' && $diffclass !== 'diffdeleted') 
				{
					if ($addedLines !== $removedLines) 
					{
						$containsOnlyEqualDiff = false;
						break;
					}
				}

				if (count($addedLines) > 0 && $addedLines === $removedLines) 
				{
					$addedLines = array();
					$removedLines = array();
				}

				if ($diffclass === 'diff') 
				{
					$i--;
					continue;
				}

				if ($diffclass === null) 
				{
					$containsOnlyEqualDiff = false;
					break;;
				}

				if ($diffclass === 'diffdeleted') 
				{
					if (count($addedLines) <= count($removedLines)) 
					{
						$containsOnlyEqualDiff = false;
						break;;
					}

					array_unshift($removedLines, $listing[$i - 1]['line']);
					$i--;
					continue;
				}

				if ($diffclass === 'diffadded') 
				{
					if (count($removedLines) > 0) 
					{
						$containsOnlyEqualDiff = false;
						break;;
					}

					array_unshift($addedLines, $listing[$i - 1]['line']);
					$i--;
					continue;
				}

				assert(false);
			}

			if ($containsOnlyEqualDiff) 
			{
				$containsOnlyEqualDiff = $addedLines === $removedLines;
			}

			// remove blocks which only contain diffclass=diff and equal removes and adds
			if ($containsOnlyEqualDiff) 
			{
				for ($j = $i - 1; $j < $index; $j++) 
				{
					unset($listing[$j]);
				}

				$index = $i - 1;
			}
		}
	}

	$listvar = &$listing[$index];
	$listvar['newpath'] = null;
	$listvar['endpath'] = null;
	$listvar['info'] = null;
	$listvar['diffclass'] = null;
	$listvar['difflines'] = null;
	$listvar['enddifflines'] = null;
	$listvar['properties'] = null;
}

$vars['success'] = false;

if (!$noinput) 
{
	// TODO: Report warning/error if comparison encounters any problems
	if ($diff = popenCommand($cmd, 'r')) 
	{
		$listing = array();
		$index = 0;
		$indiff = false;
		$indiffproper = false;
		$getLine = true;
		$node = null;
		$bufferedLine = false;

		$vars['success'] = true;

		while (!feof($diff)) 
		{
			if ($getLine) 
			{
				if ($bufferedLine === false) 
				{
					$bufferedLine = rtrim(fgets($diff), "\r\n");
				}

				$newlineR = strpos($bufferedLine, "\r");
				$newlineN = strpos($bufferedLine, "\n");
				if ($newlineR === false && $newlineN === false) 
				{
					$line = $bufferedLine;
					$bufferedLine = false;
				}
				else 
				{
					$newline = ($newlineR < $newlineN ? $newlineR : $newlineN);
					$line = substr($bufferedLine, 0, $newline);
					$bufferedLine = substr($bufferedLine, $newline + 1);
				}
			}

			clearVars();
			$getLine = true;
			if ($debug) print 'Line = "'.$line.'"<br />';
			if ($indiff) 
			{
				// If we're in a diff proper, just set up the line
				if ($indiffproper) 
				{
					if (strlen($line) > 0 && ($line[0] == ' ' || $line[0] == '+' || $line[0] == '-')) 
					{
						$subline = escape(toOutputEncoding(substr($line, 1)));
						$subline = rtrim($subline, "\n\r");
						$subline = ($subline) ? expandTabs($subline) : '&nbsp;';
						$listvar = &$listing[$index];
						$listvar['line'] = $subline;

						switch ($line[0]) 
						{
							case ' ':
								$listvar['diffclass'] = 'diff';
								if ($debug) print 'Including as diff: '.$subline.'<br />';
								break;

							case '+':
								$listvar['diffclass'] = 'diffadded';
								if ($debug) print 'Including as added: '.$subline.'<br />';
								break;

							case '-':
								$listvar['diffclass'] = 'diffdeleted';
								if ($debug) print 'Including as removed: '.$subline.'<br />';
								break;
						}
						$index++;
					} 
					else if ($line != '\ No newline at end of file') 
					{
						$indiffproper = false;
						$listing[$index++]['enddifflines'] = true;
						$getLine = false;
						if ($debug) print 'Ending lines<br />';
					}
					continue;
				}

				// Check for the start of a new diff area
				if (!strncmp($line, '@@', 2)) 
				{
					$pos = strpos($line, '+');
					$posline = substr($line, $pos);
					$sline = 0;
					$eline = 0;
					sscanf($posline, '+%d,%d', $sline, $eline);

					if ($debug) print 'sline = "'.$sline.'", eline = "'.$eline.'"<br />';

					// Check that this isn't a file deletion
					if ($sline == 0 && $eline == 0) 
					{
						$line = fgets($diff);
						if ($debug) print 'Ignoring: "'.$line.'"<br />';

						while ($line[0] == ' ' || $line[0] == '+' || $line[0] == '-') 
						{
							$line = fgets($diff);
							if ($debug) print 'Ignoring: "'.$line.'"<br />';
						}

						$getLine = false;
						if ($debug) print 'Unignoring previous - marking as deleted<br />';
						$listing[$index++]['info'] = $lang['FILEDELETED'];

					} 
					else 
					{
						$listvar = &$listing[$index];
						$listvar['difflines'] = $line;
						$sline = 0;
						$slen = 0;
						$eline = 0;
						$elen = 0;
						sscanf($line, '@@ -%d,%d +%d,%d @@', $sline, $slen, $eline, $elen);
						$listvar['rev1line'] = $sline;
						$listvar['rev1len'] = $slen;
						$listvar['rev2line'] = $eline;
						$listvar['rev2len'] = $elen;

						$indiffproper = true;

						$index++;
					}

					continue;

				} 
				else 
				{
					$indiff = false;
					if ($debug) print 'Ending diff';
				}
			}

			// Check for a new node entry
			if (strncmp(trim($line), 'Index: ', 7) == 0) 
			{
				// End the current node
				if ($node) 
				{
					$listing[$index++]['endpath'] = true;
					clearVars();
				}

				$node = trim(toOutputEncoding($line));
				$node = substr($node, 7);
				if ($node == '' || $node[0] != '/') $node = '/'.$node;

				if (substr($path2, -strlen($node)) === $node) 
				{
					$absnode = $path2;
				}
				else
				{
					$absnode = $path2;
					if (substr($absnode, -1) == '/') $absnode = substr($absnode, 0, -1);
					$absnode .= $node;
				}

				$listvar = &$listing[$index];
				$listvar['newpath'] = escape($absnode);

				$listvar['fileurl'] = $config->getURL($rep, escape($absnode), 'file').'rev='.$rev2;

				if ($debug) echo 'Creating node '.$node.'<br />';

				// Skip past the line of ='s
				$line = fgets($diff);
				if ($debug) print 'Skipping: '.$line.'<br />';

				// Check for a file addition
				$line = fgets($diff);
				if ($debug) print 'Examining: '.$line.'<br />';
				if (strpos($line, '(revision 0)')) 
				{
					$listvar['info'] = $lang['FILEADDED'];
				}

				if (strncmp(trim($line), 'Cannot display:', 15) == 0) 
				{
					$index++;
					clearVars();
					$listing[$index++]['info'] = escape(toOutputEncoding($line));
					continue;
				}

				// Skip second file info
				$line = fgets($diff);
				if ($debug) print 'Skipping: '.$line.'<br />';

				$indiff = true;
				$index++;

				continue;
			}

			if (strncmp(trim($line), 'Property changes on: ', 21) == 0) 
			{
				$propnode = trim($line);
				$propnode = substr($propnode, 21);
				if ($propnode == '' || $propnode[0] != '/') $propnode = '/'.$propnode;

				if ($debug) print 'Properties on '.$propnode.' (cur node $ '.$node.')';
				if ($propnode != $node) 
				{
					if ($node) 
					{
						$listing[$index++]['endpath'] = true;
						clearVars();
					}

					$node = $propnode;

					$listing[$index++]['newpath'] = escape(toOutputEncoding($node));
					clearVars();
				}

				$listing[$index++]['properties'] = true;
				clearVars();
				if ($debug) echo 'Creating node '.$node.'<br />';

				// Skip the row of underscores
				$line = fgets($diff);
				if ($debug) print 'Skipping: '.$line.'<br />';

				while ($line = trim(fgets($diff))) 
				{
					if (!strncmp($line, 'Index: ', 7)) 
					{
						break;
					}
					if (!strncmp($line, '##', 2) || $line == '\ No newline at end of file') 
					{
						continue;
					}
					$listing[$index++]['info'] = escape(toOutputEncoding($line));
					clearVars();
				}
				$getLine = false;

				continue;
			}

			// Check for error messages
			if (strncmp(trim($line), 'svn: ', 5) == 0) 
			{
				$listing[$index++]['info'] = urldecode($line);
				$vars['success'] = false;
				continue;
			}

			$listing[$index++]['info'] = escape(toOutputEncoding($line));
			
			if (strlen($line) === 0) 
			{
				if (!isset($vars['warning'])) 
				{
					$vars['warning'] = "No changes between revisions";
				}
			}
			
		}

		if ($node) 
		{
			clearVars();
			$listing[$index++]['endpath'] = true;
		}

		if ($debug) print_r($listing);

		if (!$rep->hasUnrestrictedReadAccess($relativePath1) || !$rep->hasUnrestrictedReadAccess($relativePath2, false)) 
		{
			// check every item for access and remove it if read access is not allowed
			$restricted = array();
			$inrestricted = false;
			foreach ($listing as $i => $item) 
			{
				if ($item['newpath'] !== null) 
				{
					$newpath = $item['newpath'];
					$inrestricted = !$rep->hasReadAccess($newpath, false);
				}

				if ($inrestricted) 
				{
					$restricted[] = $i;
				}

				if ($item['endpath'] !== null) 
				{
					$inrestricted = false;
				}
			}

			foreach ($restricted as $i) 
			{
				unset($listing[$i]);
			}

			if (count($restricted) && !count($listing)) 
			{
				$vars['error'] = $lang['NOACCESS'];
				sendHeaderForbidden();
			}
		}

		pclose($diff);
	}
}

renderTemplate('compare');
