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<?php
/**
*
* This file is part of the phpBB Forum Software package.
*
* @copyright (c) phpBB Limited <https://www.phpbb.com>
* @license GNU General Public License, version 2 (GPL-2.0)
*
* For full copyright and license information, please see
* the docs/CREDITS.txt file.
*
*/
/**
* @ignore
*/
if (!defined('IN_PHPBB'))
{
    exit;
}
/**
* Code from pear.php.net, Text_Diff-1.1.0 package
* http://pear.php.net/package/Text_Diff/
*
* Modified by phpBB Limited to meet our coding standards
* and being able to integrate into phpBB
*
* A class to render Diffs in different formats.
*
* This class renders the diff in classic diff format. It is intended that
* this class be customized via inheritance, to obtain fancier outputs.
*
* Copyright 2004-2008 The Horde Project (http://www.horde.org/)
*
* @package diff
*/
class diff_renderer
{
    /**
    * Number of leading context "lines" to preserve.
    *
    * This should be left at zero for this class, but subclasses may want to
    * set this to other values.
    */
    var $_leading_context_lines = 0;
    /**
    * Number of trailing context "lines" to preserve.
    *
    * This should be left at zero for this class, but subclasses may want to
    * set this to other values.
    */
    var $_trailing_context_lines = 0;
    /**
    * Constructor.
    */
    function __construct($params = array())
    {
        foreach ($params as $param => $value)
        {
            $v = '_' . $param;
            if (isset($this->$v))
            {
                $this->$v = $value;
            }
        }
    }
    /**
    * Get any renderer parameters.
    *
    * @return array  All parameters of this renderer object.
    */
    function get_params()
    {
        $params = array();
        foreach (get_object_vars($this) as $k => $v)
        {
            if ($k[0] == '_')
            {
                $params[substr($k, 1)] = $v;
            }
        }
        return $params;
    }
    /**
    * Renders a diff.
    *
    * @param diff &$diff A diff object.
    *
    * @return string  The formatted output.
    */
    function render(&$diff)
    {
        $xi = $yi = 1;
        $block = false;
        $context = array();
        // Create a new diff object if it is a 3-way diff
        if (is_a($diff, 'diff3'))
        {
            $diff3 = &$diff;
            $diff_1 = $diff3->get_original();
            $diff_2 = $diff3->merged_output();
            unset($diff3);
            $diff = new diff($diff_1, $diff_2);
        }
        $nlead = $this->_leading_context_lines;
        $ntrail = $this->_trailing_context_lines;
        $output = $this->_start_diff();
        $diffs = $diff->get_diff();
        foreach ($diffs as $i => $edit)
        {
            // If these are unchanged (copied) lines, and we want to keep leading or trailing context lines, extract them from the copy block.
            if (is_a($edit, 'diff_op_copy'))
            {
                // Do we have any diff blocks yet?
                if (is_array($block))
                {
                    // How many lines to keep as context from the copy block.
                    $keep = ($i == count($diffs) - 1) ? $ntrail : $nlead + $ntrail;
                    if (count($edit->orig) <= $keep)
                    {
                        // We have less lines in the block than we want for context => keep the whole block.
                        $block[] = $edit;
                    }
                    else
                    {
                        if ($ntrail)
                        {
                            // Create a new block with as many lines as we need for the trailing context.
                            $context = array_slice($edit->orig, 0, $ntrail);
                            $block[] = new diff_op_copy($context);
                        }
                        $output .= $this->_block($x0, $ntrail + $xi - $x0, $y0, $ntrail + $yi - $y0, $block);
                        $block = false;
                    }
                }
                // Keep the copy block as the context for the next block.
                $context = $edit->orig;
            }
            else
            {
                // Don't we have any diff blocks yet?
                if (!is_array($block))
                {
                    // Extract context lines from the preceding copy block.
                    $context = array_slice($context, count($context) - $nlead);
                    $x0 = $xi - count($context);
                    $y0 = $yi - count($context);
                    $block = array();
                    if ($context)
                    {
                        $block[] = new diff_op_copy($context);
                    }
                }
                $block[] = $edit;
            }
            $xi += ($edit->orig) ? count($edit->orig) : 0;
            $yi += ($edit->final) ? count($edit->final) : 0;
        }
        if (is_array($block))
        {
            $output .= $this->_block($x0, $xi - $x0, $y0, $yi - $y0, $block);
        }
        return $output . $this->_end_diff();
    }
    function _block($xbeg, $xlen, $ybeg, $ylen, &$edits)
    {
        $output = $this->_start_block($this->_block_header($xbeg, $xlen, $ybeg, $ylen));
        foreach ($edits as $edit)
        {
            switch (get_class($edit))
            {
                case 'diff_op_copy':
                    $output .= $this->_context($edit->orig);
                break;
                case 'diff_op_add':
                    $output .= $this->_added($edit->final);
                break;
                case 'diff_op_delete':
                    $output .= $this->_deleted($edit->orig);
                break;
                case 'diff_op_change':
                    $output .= $this->_changed($edit->orig, $edit->final);
                break;
            }
        }
        return $output . $this->_end_block();
    }
    function _start_diff()
    {
        return '';
    }
    function _end_diff()
    {
        return '';
    }
    function _block_header($xbeg, $xlen, $ybeg, $ylen)
    {
        if ($xlen > 1)
        {
            $xbeg .= ',' . ($xbeg + $xlen - 1);
        }
        if ($ylen > 1)
        {
            $ybeg .= ',' . ($ybeg + $ylen - 1);
        }
        // this matches the GNU Diff behaviour
        if ($xlen && !$ylen)
        {
            $ybeg--;
        }
        else if (!$xlen)
        {
            $xbeg--;
        }
        return $xbeg . ($xlen ? ($ylen ? 'c' : 'd') : 'a') . $ybeg;
    }
    function _start_block($header)
    {
        return $header . "\n";
    }
    function _end_block()
    {
        return '';
    }
    function _lines($lines, $prefix = ' ')
    {
        return $prefix . implode("\n$prefix", $lines) . "\n";
    }
    function _context($lines)
    {
        return $this->_lines($lines, '  ');
    }
    function _added($lines)
    {
        return $this->_lines($lines, '> ');
    }
    function _deleted($lines)
    {
        return $this->_lines($lines, '< ');
    }
    function _changed($orig, $final)
    {
        return $this->_deleted($orig) . "---\n" . $this->_added($final);
    }
    /**
    * Our function to get the diff
    */
    function get_diff_content($diff)
    {
        return $this->render($diff);
    }
}
/**
* Renders a unified diff
* @package diff
*/
class diff_renderer_unified extends diff_renderer
{
    var $_leading_context_lines = 4;
    var $_trailing_context_lines = 4;
    /**
    * Our function to get the diff
    */
    function get_diff_content($diff)
    {
        return nl2br($this->render($diff));
    }
    function _block_header($xbeg, $xlen, $ybeg, $ylen)
    {
        if ($xlen != 1)
        {
            $xbeg .= ',' . $xlen;
        }
        if ($ylen != 1)
        {
            $ybeg .= ',' . $ylen;
        }
        return '<div class="diff"><big class="info">@@ -' . $xbeg . ' +' . $ybeg . ' @@</big></div>';
    }
    function _context($lines)
    {
        return '<pre class="diff context">' . htmlspecialchars($this->_lines($lines, ' '), ENT_COMPAT) . '<br /></pre>';
    }
    function _added($lines)
    {
        return '<pre class="diff added">' . htmlspecialchars($this->_lines($lines, '+'), ENT_COMPAT) . '<br /></pre>';
    }
    function _deleted($lines)
    {
        return '<pre class="diff removed">' . htmlspecialchars($this->_lines($lines, '-'), ENT_COMPAT) . '<br /></pre>';
    }
    function _changed($orig, $final)
    {
        return $this->_deleted($orig) . $this->_added($final);
    }
    function _start_diff()
    {
        $start = '<div class="file">';
        return $start;
    }
    function _end_diff()
    {
        return '</div>';
    }
    function _end_block()
    {
        return '';
    }
}
/**
* "Inline" diff renderer.
*
* This class renders diffs in the Wiki-style "inline" format.
*
* @author  Ciprian Popovici
* @package diff
*/
class diff_renderer_inline extends diff_renderer
{
    var $_leading_context_lines = 10000;
    var $_trailing_context_lines = 10000;
    // Prefix and suffix for inserted text
    var $_ins_prefix = '<span class="ins">';
    var $_ins_suffix = '</span>';
    // Prefix and suffix for deleted text
    var $_del_prefix = '<span class="del">';
    var $_del_suffix = '</span>';
    var $_block_head = '';
    // What are we currently splitting on? Used to recurse to show word-level
    var $_split_level = 'lines';
    /**
    * Our function to get the diff
    */
    function get_diff_content($diff)
    {
        return '<pre>' . nl2br($this->render($diff)) . '<br /></pre>';
    }
    function _start_diff()
    {
        return '';
    }
    function _end_diff()
    {
        return '';
    }
    function _block_header($xbeg, $xlen, $ybeg, $ylen)
    {
        return $this->_block_head;
    }
    function _start_block($header)
    {
        return $header;
    }
    function _lines($lines, $prefix = ' ', $encode = true)
    {
        if ($encode)
        {
            array_walk($lines, array(&$this, '_encode'));
        }
        if ($this->_split_level == 'words')
        {
            return implode('', $lines);
        }
        else
        {
            return implode("\n", $lines) . "\n";
        }
    }
    function _added($lines)
    {
        array_walk($lines, array(&$this, '_encode'));
        $lines[0] = $this->_ins_prefix . $lines[0];
        $lines[count($lines) - 1] .= $this->_ins_suffix;
        return $this->_lines($lines, ' ', false);
    }
    function _deleted($lines, $words = false)
    {
        array_walk($lines, array(&$this, '_encode'));
        $lines[0] = $this->_del_prefix . $lines[0];
        $lines[count($lines) - 1] .= $this->_del_suffix;
        return $this->_lines($lines, ' ', false);
    }
    function _changed($orig, $final)
    {
        // If we've already split on words, don't try to do so again - just display.
        if ($this->_split_level == 'words')
        {
            $prefix = '';
            while ($orig[0] !== false && $final[0] !== false && substr($orig[0], 0, 1) == ' ' && substr($final[0], 0, 1) == ' ')
            {
                $prefix .= substr($orig[0], 0, 1);
                $orig[0] = substr($orig[0], 1);
                $final[0] = substr($final[0], 1);
            }
            return $prefix . $this->_deleted($orig) . $this->_added($final);
        }
        $text1 = implode("\n", $orig);
        $text2 = implode("\n", $final);
        // Non-printing newline marker.
        $nl = "\0";
        // We want to split on word boundaries, but we need to preserve whitespace as well.
        // Therefore we split on words, but include all blocks of whitespace in the wordlist.
        $splitted_text_1 = $this->_split_on_words($text1, $nl);
        $splitted_text_2 = $this->_split_on_words($text2, $nl);
        $diff = new diff($splitted_text_1, $splitted_text_2);
        unset($splitted_text_1, $splitted_text_2);
        // Get the diff in inline format.
        $renderer = new diff_renderer_inline(array_merge($this->get_params(), array('split_level' => 'words')));
        // Run the diff and get the output.
        return str_replace($nl, "\n", $renderer->render($diff)) . "\n";
    }
    function _split_on_words($string, $newline_escape = "\n")
    {
        // Ignore \0; otherwise the while loop will never finish.
        $string = str_replace("\0", '', $string);
        $words = array();
        $length = strlen($string);
        $pos = 0;
        $tab_there = true;
        while ($pos < $length)
        {
            // Check for tabs... do not include them
            if ($tab_there && substr($string, $pos, 1) === "\t")
            {
                $words[] = "\t";
                $pos++;
                continue;
            }
            else
            {
                $tab_there = false;
            }
            // Eat a word with any preceding whitespace.
            $spaces = strspn(substr($string, $pos), " \n");
            $nextpos = strcspn(substr($string, $pos + $spaces), " \n");
            $words[] = str_replace("\n", $newline_escape, substr($string, $pos, $spaces + $nextpos));
            $pos += $spaces + $nextpos;
        }
        return $words;
    }
    function _encode(&$string)
    {
        $string = htmlspecialchars($string, ENT_COMPAT);
    }
}
/**
* "raw" diff renderer.
* This class could be used to output a raw unified patch file
*
* @package diff
*/
class diff_renderer_raw extends diff_renderer
{
    var $_leading_context_lines = 4;
    var $_trailing_context_lines = 4;
    /**
    * Our function to get the diff
    */
    function get_diff_content($diff)
    {
        return '<textarea style="height: 290px;" rows="15" cols="76" class="full">' . htmlspecialchars($this->render($diff), ENT_COMPAT) . '</textarea>';
    }
    function _block_header($xbeg, $xlen, $ybeg, $ylen)
    {
        if ($xlen != 1)
        {
            $xbeg .= ',' . $xlen;
        }
        if ($ylen != 1)
        {
            $ybeg .= ',' . $ylen;
        }
        return '@@ -' . $xbeg . ' +' . $ybeg . ' @@';
    }
    function _context($lines)
    {
        return $this->_lines($lines, ' ');
    }
    function _added($lines)
    {
        return $this->_lines($lines, '+');
    }
    function _deleted($lines)
    {
        return $this->_lines($lines, '-');
    }
    function _changed($orig, $final)
    {
        return $this->_deleted($orig) . $this->_added($final);
    }
}
/**
* "chora (Horde)" diff renderer - similar style.
* This renderer class is a modified human_readable function from the Horde Framework.
*
* @package diff
*/
class diff_renderer_side_by_side extends diff_renderer
{
    var $_leading_context_lines = 3;
    var $_trailing_context_lines = 3;
    var $lines = array();
    // Hold the left and right columns of lines for change blocks.
    var $cols;
    var $state;
    var $data = false;
    /**
    * Our function to get the diff
    */
    function get_diff_content($diff)
    {
        global $user;
        $output = '';
        $output .= '<table cellspacing="0" class="hrdiff">
<caption>
    <span class="unmodified">&nbsp;</span> ' . $user->lang['LINE_UNMODIFIED'] . '
    <span class="added">&nbsp;</span> ' . $user->lang['LINE_ADDED'] . '
    <span class="modified">&nbsp;</span> ' . $user->lang['LINE_MODIFIED'] . '
    <span class="removed">&nbsp;</span> ' . $user->lang['LINE_REMOVED'] . '
</caption>
<tbody>
';
        $this->render($diff);
        // Is the diff empty?
        if (!count($this->lines))
        {
            $output .= '<tr><th colspan="2">' . $user->lang['NO_VISIBLE_CHANGES'] . '</th></tr>';
        }
        else
        {
            // Iterate through every header block of changes
            foreach ($this->lines as $header)
            {
                $output .= '<tr><th>' . $user->lang['LINE'] . ' ' . $header['oldline'] . '</th><th>' . $user->lang['LINE'] . ' ' . $header['newline'] . '</th></tr>';
                // Each header block consists of a number of changes (add, remove, change).
                $current_context = '';
                foreach ($header['contents'] as $change)
                {
                    if (!empty($current_context) && $change['type'] != 'empty')
                    {
                        $line = $current_context;
                        $current_context = '';
                        $output .= '<tr class="unmodified"><td><pre>' . ((strlen($line)) ? $line : '&nbsp;') . '<br /></pre></td>
                            <td><pre>' . ((strlen($line)) ? $line : '&nbsp;') . '<br /></pre></td></tr>';
                    }
                    switch ($change['type'])
                    {
                        case 'add':
                            $line = '';
                            foreach ($change['lines'] as $_line)
                            {
                                $line .= htmlspecialchars($_line, ENT_COMPAT) . '<br />';
                            }
                            $output .= '<tr><td class="added_empty">&nbsp;</td><td class="added"><pre>' . ((strlen($line)) ? $line : '&nbsp;') . '<br /></pre></td></tr>';
                        break;
                        case 'remove':
                            $line = '';
                            foreach ($change['lines'] as $_line)
                            {
                                $line .= htmlspecialchars($_line, ENT_COMPAT) . '<br />';
                            }
                            $output .= '<tr><td class="removed"><pre>' . ((strlen($line)) ? $line : '&nbsp;') . '<br /></pre></td><td class="removed_empty">&nbsp;</td></tr>';
                        break;
                        case 'empty':
                            $current_context .= htmlspecialchars($change['line'], ENT_COMPAT) . '<br />';
                        break;
                        case 'change':
                            // Pop the old/new stacks one by one, until both are empty.
                            $oldsize = count($change['old']);
                            $newsize = count($change['new']);
                            $left = $right = '';
                            for ($row = 0, $row_max = max($oldsize, $newsize); $row < $row_max; ++$row)
                            {
                                $left .= isset($change['old'][$row]) ? htmlspecialchars($change['old'][$row], ENT_COMPAT) : '';
                                $left .= '<br />';
                                $right .= isset($change['new'][$row]) ? htmlspecialchars($change['new'][$row], ENT_COMPAT) : '';
                                $right .= '<br />';
                            }
                            $output .= '<tr>';
                            if (!empty($left))
                            {
                                $output .= '<td class="modified"><pre>' . $left . '<br /></pre></td>';
                            }
                            else if ($row < $oldsize)
                            {
                                $output .= '<td class="modified">&nbsp;</td>';
                            }
                            else
                            {
                                $output .= '<td class="unmodified">&nbsp;</td>';
                            }
                            if (!empty($right))
                            {
                                $output .= '<td class="modified"><pre>' . $right . '<br /></pre></td>';
                            }
                            else if ($row < $newsize)
                            {
                                $output .= '<td class="modified">&nbsp;</td>';
                            }
                            else
                            {
                                $output .= '<td class="unmodified">&nbsp;</td>';
                            }
                            $output .= '</tr>';
                        break;
                    }
                }
                if (!empty($current_context))
                {
                    $line = $current_context;
                    $current_context = '';
                    $output .= '<tr class="unmodified"><td><pre>' . ((strlen($line)) ? $line : '&nbsp;') . '<br /></pre></td>';
                    $output .= '<td><pre>' . ((strlen($line)) ? $line : '&nbsp;') . '<br /></pre></td></tr>';
                }
            }
        }
        $output .= '</tbody></table>';
        return $output;
    }
    function _start_diff()
    {
        $this->lines = array();
        $this->data = false;
        $this->cols = array(array(), array());
        $this->state = 'empty';
        return '';
    }
    function _end_diff()
    {
        // Just flush any remaining entries in the columns stack.
        switch ($this->state)
        {
            case 'add':
                $this->data['contents'][] = array('type' => 'add', 'lines' => $this->cols[0]);
            break;
            case 'remove':
                // We have some removal lines pending in our stack, so flush them.
                $this->data['contents'][] = array('type' => 'remove', 'lines' => $this->cols[0]);
            break;
            case 'change':
                // We have both remove and addition lines, so this is a change block.
                $this->data['contents'][] = array('type' => 'change', 'old' => $this->cols[0], 'new' => $this->cols[1]);
            break;
        }
        if ($this->data !== false)
        {
            $this->lines[] = $this->data;
        }
        return '';
    }
    function _block_header($xbeg, $xlen, $ybeg, $ylen)
    {
        // Push any previous header information to the return stack.
        if ($this->data !== false)
        {
            $this->lines[] = $this->data;
        }
        $this->data = array('type' => 'header', 'oldline' => $xbeg, 'newline' => $ybeg, 'contents' => array());
        $this->state = 'dump';
    }
    function _added($lines)
    {
        array_walk($lines, array(&$this, '_perform_add'));
    }
    function _perform_add($line)
    {
        if ($this->state == 'empty')
        {
            return '';
        }
        // This is just an addition line.
        if ($this->state == 'dump' || $this->state == 'add')
        {
            // Start adding to the addition stack.
            $this->cols[0][] = $line;
            $this->state = 'add';
        }
        else
        {
            // This is inside a change block, so start accumulating lines.
            $this->state = 'change';
            $this->cols[1][] = $line;
        }
    }
    function _deleted($lines)
    {
        array_walk($lines, array(&$this, '_perform_delete'));
    }
    function _perform_delete($line)
    {
        // This is a removal line.
        $this->state = 'remove';
        $this->cols[0][] = $line;
    }
    function _context($lines)
    {
        array_walk($lines, array(&$this, '_perform_context'));
    }
    function _perform_context($line)
    {
        // An empty block with no action.
        switch ($this->state)
        {
            case 'add':
                $this->data['contents'][] = array('type' => 'add', 'lines' => $this->cols[0]);
            break;
            case 'remove':
                // We have some removal lines pending in our stack, so flush them.
                $this->data['contents'][] = array('type' => 'remove', 'lines' => $this->cols[0]);
            break;
            case 'change':
                // We have both remove and addition lines, so this is a change block.
                $this->data['contents'][] = array('type' => 'change', 'old' => $this->cols[0], 'new' => $this->cols[1]);
            break;
        }
        $this->cols = array(array(), array());
        $this->data['contents'][] = array('type' => 'empty', 'line' => $line);
        $this->state = 'dump';
    }
    function _changed($orig, $final)
    {
        return $this->_deleted($orig) . $this->_added($final);
    }
}