<?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 ($path1 && strpos($path1, '@'))
{
        list($path1, $rev1) = explode('@', $path1);
}
else if ($path1 && (strpos($path1, '@') === 0))
{
        // Something went wrong. The path is missing.
        $rev1 = substr($path1, 1);
        $path1 = '/';
}

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

$vars['safepath1'] = escape($path1);
$vars['safepath2'] = escape($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), "\n\r");
                                }

                                $newlineR = strpos($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 ($line && ($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, $absnode, 'file').'rev='.$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(rtrim($line, "\n\r")));
                                        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 ($line = rtrim(fgets($diff), "\n\r"))
                                {
                                        if (!strncmp(trim($line), 'Index: ', 7))
                                        {
                                                break;
                                        }
                                        if (!strncmp(trim($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');