<?php

/**

 * "Inline" diff renderer.

 *

 * Copyright 2004-2010 The Horde Project (http://www.horde.org/)

 *

 * See the enclosed file COPYING for license information (LGPL). If you did

 * not receive this file, see http://opensource.org/licenses/lgpl-license.php.

 *

 * @author  Ciprian Popovici

 * @package Text_Diff

 */

/** Text_Diff_Renderer */

// WP #7391

require_once dirname(dirname(__FILE__)) . '/Renderer.php';

/**

 * "Inline" diff renderer.

 *

 * This class renders diffs in the Wiki-style "inline" format.

 *

 * @author  Ciprian Popovici

 * @package Text_Diff

 */

class Text_Diff_Renderer_inline extends Text_Diff_Renderer {

    /**

     * Number of leading context "lines" to preserve.

     *

     * @var integer

     */

    var $_leading_context_lines = 10000;

    /**

     * Number of trailing context "lines" to preserve.

     *

     * @var integer

     */

    var $_trailing_context_lines = 10000;

    /**

     * Prefix for inserted text.

     *

     * @var string

     */

    var $_ins_prefix = '<ins>';

    /**

     * Suffix for inserted text.

     *

     * @var string

     */

    var $_ins_suffix = '</ins>';

    /**

     * Prefix for deleted text.

     *

     * @var string

     */

    var $_del_prefix = '<del>';

    /**

     * Suffix for deleted text.

     *

     * @var string

     */

    var $_del_suffix = '</del>';

    /**

     * Header for each change block.

     *

     * @var string

     */

    var $_block_header = '';

    /**

     * Whether to split down to character-level.

     *

     * @var boolean

     */

    var $_split_characters = false;

    /**

     * What are we currently splitting on? Used to recurse to show word-level

     * or character-level changes.

     *

     * @var string

     */

    var $_split_level = 'lines';

    function _blockHeader($xbeg, $xlen, $ybeg, $ylen)

    {

        return $this->_block_header;

    }

    function _startBlock($header)

    {

        return $header;

    }

    function _lines($lines, $prefix = ' ', $encode = true)

    {

        if ($encode) {

            array_walk($lines, array(&$this, '_encode'));

        }

        if ($this->_split_level == 'lines') {

            return implode("\n", $lines) . "\n";

        } else {

            return implode('', $lines);

        }

    }

    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 characters, just display. */

        if ($this->_split_level == 'characters') {

            return $this->_deleted($orig)

                . $this->_added($final);

        }

        /* If we've already split on words, 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";

        if ($this->_split_characters) {

            $diff = new Text_Diff('native',

                                  array(preg_split('//', $text1),

                                        preg_split('//', $text2)));

        } else {

            /* 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. */

            $diff = new Text_Diff('native',

                                  array($this->_splitOnWords($text1, $nl),

                                        $this->_splitOnWords($text2, $nl)));

        }

        /* Get the diff in inline format. */

        $renderer = new Text_Diff_Renderer_inline

            (array_merge($this->getParams(),

                         array('split_level' => $this->_split_characters ? 'characters' : 'words')));

        /* Run the diff and get the output. */

        return str_replace($nl, "\n", $renderer->render($diff)) . "\n";

    }

    function _splitOnWords($string, $newlineEscape = "\n")

    {

        // Ignore \0; otherwise the while loop will never finish.

        $string = str_replace("\0", '', $string);

        $words = array();

        $length = strlen($string);

        $pos = 0;

        while ($pos < $length) {

            // Eat a word with any preceding whitespace.

            $spaces = strspn(substr($string, $pos), " \n");

            $nextpos = strcspn(substr($string, $pos + $spaces), " \n");

            $words[] = str_replace("\n", $newlineEscape, substr($string, $pos, $spaces + $nextpos));

            $pos += $spaces + $nextpos;

        }

        return $words;

    }

    function _encode(&$string)

    {

        $string = htmlspecialchars($string);

    }

}