<?php
/*
 * MODX Revolution
 *
 * Copyright 2006-2011 by MODX, LLC.
 * All rights reserved.
 *
 * 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
 */

/**
 * Provides the default output filter implementation for modElement processing.
 * @package modx
 * @subpackage filters
 */

/**
 * Base output filter implementation for modElement processing, based on phX.
 *
 * @package modx
 * @subpackage filters
 */
class modOutputFilter {
    /**
     * @var modX A reference to the modX instance
     */
    public $modx= null;

    /**
     * @param modX $modx A reference to the modX instance
     * @return modOutputFilter A new instance of the modOutputFilter class
     */
    function __construct(modX &$modx) {
        $this->modx= &$modx;
    }

    /**
     * Filters the output
     * 
     * @param mixed $element The element to filter
     */
    public function filter(&$element) {
        $usemb = function_exists('mb_strlen') && (boolean)$this->modx->getOption('use_multibyte',null,false);
        $encoding = $this->modx->getOption('modx_charset',null,'UTF-8');

        $output= & $element->_output;
        $inputFilter = $element->getInputFilter();
        if ($inputFilter !== null && $inputFilter->hasCommands()) {
            $modifier_cmd = $inputFilter->getCommands();
            $modifier_value = $inputFilter->getModifiers();
            $count = count($modifier_cmd);
            $condition = array();

            for ($i= 0; $i < $count; $i++) {

                $m_cmd = $modifier_cmd[$i];
                $m_val = $modifier_value[$i];

                $this->log('Processing Modifier: ' . $m_cmd . ' (parameters: ' . $m_val . ')');

                $output = trim($output);

                try {
                    switch ($m_cmd) {
                        /* conditional operators */
                        /* @todo these conditionals should be removed because there are cleaner ways to do this now */
                        case 'input':
                        case 'if':
                            $output= $m_val;
                            break;
                        case 'eq':
                        case 'is':
                        case 'equals':
                        case 'equalto':
                        case 'isequal':
                        case 'isequalto':
                            $condition[]= intval(($output == $m_val));
                            break;
                        case 'ne':
                        case 'neq':
                        case 'isnot':
                        case 'isnt':
                        case 'notequals':
                        case 'notequalto':
                            $condition[]= intval(($output != $m_val));
                            break;
                        case 'gte':
                        case 'isgte':
                        case 'eg':
                        case 'ge':
                        case 'equalorgreaterthan':
                        case 'greaterthanorequalto':
                            $condition[]= intval(($output >= $m_val));
                            break;
                        case 'lte':
                        case 'islte':
                        case 'le':
                        case 'el':
                        case 'lessthanorequalto':
                        case 'equaltoorlessthan':
                            $condition[]= intval(($output <= $m_val));
                            break;
                        case 'gt':
                        case 'isgt':
                        case 'greaterthan':
                        case 'isgreaterthan':
                            $condition[]= intval(($output > $m_val));
                            break;
                        case 'lt':
                        case 'islt':
                        case 'lessthan':
                        case 'lowerthan':
                        case 'islessthan':
                        case 'islowerthan':
                            $condition[]= intval(($output < $m_val));
                            break;
                        case 'ismember':
                        case 'memberof':
                        case 'mo': /* Is Member Of  (same as inrole but this one can be stringed as a conditional) */
                            if (empty($output) || $output == "&_PHX_INTERNAL_&") {
                                $output= $this->modx->user->get('id');
                            }
                            $grps= (strlen($m_val) > 0) ? explode(',', $m_val) : array ();
                            $user = $this->modx->getObject('modUser',$output);
                            $condition[]= $user->isMember($grps);
                            break;
                        case 'or':
                            $condition[]= "||";
                            break;
                        case 'and':
                            $condition[]= "&&";
                            break;
                        case 'hide':
                            $m_con = intval(eval("return (" . join(' ', $condition) . ");"));
                            if ($m_con) {
                                $output= null;
                            }
                            break;
                        case 'show':
                            $m_con = intval(eval("return (" . join(' ', $condition) . ");"));
                            if (!$m_con) {
                                $output= null;
                            }
                            break;
                        case 'then':
                            $m_con = intval(eval("return (" . join(' ', $condition) . ");"));
                            if ($m_con) {
                                $output= $m_val;
                            } else {
                                $output= null;
                            }
                            break;
                        case 'else':
                            $m_con = intval(eval("return (" . join(' ', $condition) . ");"));
                            if (!$m_con) {
                                $output= $m_val;
                            }
                            break;
                        case 'select':
                            $raw= explode("&", $m_val);
                            $map= array ();
                            for ($m= 0; $m < (count($raw)); $m++) {
                                $mi= explode("=", $raw[$m]);
                                $map[$mi[0]]= $mi[1];
                            }
                            $output= $map[$output];
                            break;
                            /* #####  End of Conditional Modifiers */

                        /* #####  String Modifiers */
                        case 'cat': /* appends the options value (if not empty) to the input value */
                            if (!empty($m_val))
                                $output = $output . $m_val;
                            break;
                        case 'lcase':
                        case 'lowercase':
                        case 'strtolower':
                            /* See PHP's strtolower - http://www.php.net/manual/en/function.strtolower.php */
                            $output = $usemb ? mb_strtolower($output,$encoding) : strtolower($output);
                            break;
                        case 'ucase':
                        case 'uppercase':
                        case 'strtoupper':
                            /* See PHP's strtoupper - http://www.php.net/manual/en/function.strtoupper.php */
                            $output = $usemb ? mb_strtoupper($output,$encoding) : strtoupper($output);
                            break;
                        case 'ucwords':
                            /* See PHP's ucwords - http://www.php.net/manual/en/function.ucwords.php */
                            $output = $usemb ? mb_convert_case($output,MB_CASE_TITLE,$encoding) : ucwords($output);
                            break;
                        case 'ucfirst':
                            /* See PHP's ucfirst - http://www.php.net/manual/en/function.ucfirst.php */
                            if ($usemb) {
                                $output = mb_strtoupper(mb_substr($output,0,1)) . mb_substr($output, 1);
                            } else {
                                $output = ucfirst($output);
                            }
                            break;
                        case 'htmlent':
                        case 'htmlentities':
                            /* See PHP's htmlentities - http://www.php.net/manual/en/function.htmlentities.php */
                            $output = htmlentities($output,ENT_QUOTES,$encoding);
                            break;
                        case 'esc':
                        case 'escape':
                            $output = preg_replace("/&amp;(#[0-9]+|[a-z]+);/i", "&$1;", htmlspecialchars($output));
                            $output = str_replace(array ("[", "]", "`"), array ("&#91;", "&#93;", "&#96;"), $output);
                            break;
                        case 'strip':
                            /* Replaces all linebreaks, tabs and multiple spaces with just one space */
                            $output= preg_replace("/\s+/"," ",$output);
                            break;
                        case 'stripString':
                            /* strips string of this value */
                            $output= str_replace($m_val,'',$output);
                            break;
                        case 'replace':
                            /* replaces one value with another */
                            $opt = explode('==',$m_val);
                            if (count($opt) >= 2) {
                                $output = str_replace($opt[0],$opt[1],$output);
                            }
                            break;
                        case 'notags':
                        case 'striptags':
                        case 'stripTags':
                        case 'strip_tags':
                            /* See PHP's strip_tags - http://www.php.net/manual/en/function.strip_tags.php */
                            if (!empty($m_val)) {
                                $output= strip_tags($output,$m_val);
                            } else {
                                $output= strip_tags($output);
                            }
                            break;
                        case 'length':
                        case 'len':
                        case 'strlen':
                            /* See PHP's strlen - http://www.php.net/manual/en/function.strlen.php */
                            $output = $usemb ? mb_strlen($output,$encoding) : strlen($output);
                            break;
                        case 'reverse':
                        case 'strrev':
                            /* See PHP's strrev - http://www.php.net/manual/en/function.strrev.php */
                            if ($usemb) {
                                $ar = array();
                                preg_match_all('/(\d+)?./us', $output, $ar);
                                $output = join('',array_reverse($ar[0]));
                            } else {
                                $output = strrev($output);
                            }
                            break;
                        case 'wordwrap':
                            /* See PHP's wordwrap - http://www.php.net/manual/en/function.wordwrap.php */
                            $wrapat= intval($m_val);
                            if ($wrapat) {
                                $output= wordwrap($output, $wrapat,"<br />\n ", 0);
                            } else {
                                $output= wordwrap($output, 70,"<br />\n", 0);
                            }
                            break;
                        case 'wordwrapcut':
                            /* See PHP's wordwrap - http://www.php.net/manual/en/function.wordwrap.php */
                            $wrapat= intval($m_val);
                            if ($wrapat) {
                                $output= wordwrap($output, $wrapat,"<br />\n ", 1);
                            } else {
                                $output= wordwrap($output, 70,"<br />\n", 1);
                            }
                            break;
                        case 'limit':
                            /* default: 100 */
                            $limit= intval($m_val) ? intval($m_val) : 100;
                            /* ensure that filter correctly counts special chars */
                            $str = html_entity_decode($output,ENT_COMPAT,$encoding);
                            if ($usemb) {
                                $output= mb_substr($str,0,$limit,$encoding);
                            } else {
                                $output= substr($str,0,$limit);
                            }
                            break;
                        case 'ellipsis':
                            $limit= intval($m_val) ? intval($m_val) : 100;

                            /* ensure that filter correctly counts special chars */
                            $str = html_entity_decode($output,ENT_COMPAT,$encoding);
                            if ($usemb) {
                                if (mb_strlen($str,$encoding) > $limit) {
                                    $output = mb_substr($str,0,$limit,$encoding).'&#8230;';
                                }
                            } else if (strlen($str) > $limit) {
                                $output = substr($str,0,$limit).'&#8230;';
                            }
                            break;
                        /* #####  Special functions */

                        case 'tag':
                            /* Displays the raw element tag without :tag */
                            $tag = $element->_tag;
                            $tag = htmlentities($tag,ENT_QUOTES,$encoding);
                            $tag = str_replace(array ("[", "]", "`"), array ("&#91;", "&#93;", "&#96;"), $tag);
                            $tag = str_replace(":tag","",$tag);
                            $output = $tag;
                            break;

                        case 'math':
                            /* Returns the result of an advanced calculation (expensive) */
                            $filter= preg_replace("~([a-zA-Z\n\r\t\s])~", "", $m_val);
                            $filter= str_replace('?', $output, $filter);
                            $output= eval("return " . $filter . ";");
                            break;

                        case 'add':
                        case 'increment':
                        case 'incr':
                            /* Returns input incremented by option (default: +1) */
                            if (empty($m_val))
                                $m_val = 1;
                            $output = (float)$output + (float)$m_val;
                            break;

                        case 'subtract':
                        case 'decrement':
                        case 'decr':
                            /* Returns input decremented by option (default: -1) */
                            if (empty($m_val))
                                $m_val = 1;
                            $output = (float)$output - (float)$m_val;
                            break;

                        case 'multiply':
                        case 'mpy':
                            /* Returns input multiplied by option (default: *2) */
                            if (empty($m_val))
                                $m_val = 1;
                            $output = (float)$output * (float)$m_val;
                            break;

                        case 'divide':
                        case 'div':
                            /* Returns input divided by option (default: /2) */
                            if (empty($m_val))
                                $m_val = 2;
                            $output = (float)$output / (float)$m_val;
                            break;

                        case 'modulus':
                        case 'mod':
                            /* Returns the option modulus on input (default: %2, returns 0 or 1) */
                            if (empty($m_val))
                                $m_val = 2;
                            $output = (float)$output % (float)$m_val;
                            break;

                        case 'default':
                        case 'ifempty':
                        case 'isempty':
                        case 'empty':
                            /* Returns the input value if empty */
                            if (empty($output))
                                $output= $m_val;
                            break;

                        case 'ifnotempty':
                        case 'isnotempty':
                        case 'notempty':
                        case '!empty':
                            /* returns input value if not empty */
                            if (!empty($output))
                                $output= $m_val;
                            break;

                        case 'nl2br':
                            /* See PHP's nl2br - http://www.php.net/manual/en/function.nl2br.php */
                            $output= nl2br($output);
                            break;

                        case 'date':
                            /* See PHP's strftime - http://www.php.net/manual/en/function.strftime.php */
                            if (empty($m_val))
                                $m_val = "%A, %d %B %Y %H:%M:%S"; /* @todo this should be modx default date/time format? Lexicon? */
                            $value = 0 + $output;
                            if ($value != 0 && $value != -1) {
                                $output= strftime($m_val, 0 + $output);
                            } else {
                                $output= '';
                            }
                            break;

                        case 'strtotime':
                            /* See PHP's strtotime() function - http://www.php.net/strtotime */
                            if (!empty($output)) {
                                $output = strtotime($output);
                            } else {
                                $output = '';
                            }
                            break;
                        case 'fuzzydate':
                            /* displays a "fuzzy" date reference */
                            if (empty($this->modx->lexicon)) $this->modx->getService('lexicon','modLexicon');
                            $this->modx->lexicon->load('filters');
                            if (empty($m_val)) $m_val= '%b %e';
                            if (!empty($output)) {
                                $time = strtotime($output);
                                if ($time >= strtotime('today')) {
                                    $output = $this->modx->lexicon('today_at',array('time' => strftime('%I:%M %p',$time)));
                                } elseif ($time >= strtotime('yesterday')) {
                                    $output = $this->modx->lexicon('yesterday_at',array('time' => strftime('%I:%M %p',$time)));
                                } else {
                                    $output = strftime($m_val, $time);
                                }
                            } else {
                                $output = '&mdash;';
                            }
                            break;
                        case 'ago':
                            /* calculates relative time ago from a timestamp */
                            if (empty($output)) break;
                            if (empty($this->modx->lexicon)) $this->modx->getService('lexicon','modLexicon');
                            $this->modx->lexicon->load('filters');

                            $agoTS = array();
                            $uts['start'] = strtotime($output);
                            $uts['end'] = time();
                            if( $uts['start']!==-1 && $uts['end']!==-1 ) {
                              if( $uts['end'] >= $uts['start'] ) {
                                $diff = $uts['end'] - $uts['start'];

                                $years = intval((floor($diff/31536000)));
                                if ($years) $diff = $diff % 31536000;

                                $months = intval((floor($diff/2628000)));
                                if ($months) $diff = $diff % 2628000;

                                $weeks = intval((floor($diff/604800)));
                                if ($weeks) $diff = $diff % 604800;

                                $days = intval((floor($diff/86400)));
                                if ($days) $diff = $diff % 86400;

                                $hours = intval((floor($diff/3600)));
                                if ($hours) $diff = $diff % 3600;

                                $minutes = intval((floor($diff/60)));
                                if ($minutes) $diff = $diff % 60;

                                $diff = intval($diff);
                                $agoTS = array(
                                  'years' => $years,
                                  'months' => $months,
                                  'weeks' => $weeks,
                                  'days' => $days,
                                  'hours' => $hours,
                                  'minutes' => $minutes,
                                  'seconds' => $diff,
                                );
                              }
                            }

                            $ago = array();
                            if (!empty($agoTS['years'])) {
                              $ago[] = $this->modx->lexicon(($agoTS['years'] > 1 ? 'ago_years' : 'ago_year'),array('time' => $agoTS['years']));
                            }
                            if (!empty($agoTS['months'])) {
                              $ago[] = $this->modx->lexicon(($agoTS['months'] > 1 ? 'ago_months' : 'ago_month'),array('time' => $agoTS['months']));
                            }
                            if (!empty($agoTS['weeks']) && empty($agoTS['years'])) {
                              $ago[] = $this->modx->lexicon(($agoTS['weeks'] > 1 ? 'ago_weeks' : 'ago_week'),array('time' => $agoTS['weeks']));
                            }
                            if (!empty($agoTS['days']) && empty($agoTS['months']) && empty($agoTS['years'])) {
                              $ago[] = $this->modx->lexicon(($agoTS['days'] > 1 ? 'ago_days' : 'ago_day'),array('time' => $agoTS['days']));
                            }
                            if (!empty($agoTS['hours']) && empty($agoTS['weeks']) && empty($agoTS['months']) && empty($agoTS['years'])) {
                              $ago[] = $this->modx->lexicon(($agoTS['hours'] > 1 ? 'ago_hours' : 'ago_hour'),array('time' => $agoTS['hours']));
                            }
                            if (!empty($agoTS['minutes']) && empty($agoTS['days']) && empty($agoTS['weeks']) && empty($agoTS['months']) && empty($agoTS['years'])) {
                              $ago[] = $this->modx->lexicon('ago_minutes',array('time' => $agoTS['minutes']));
                            }
                            if (empty($ago)) { /* handle <1 min */
                              $ago[] = $this->modx->lexicon('ago_seconds',array('time' => $agoTS['seconds']));
                            }
                            $output = implode(', ',$ago);
                            $output = $this->modx->lexicon('ago',array('time' => $output));
                            break;
                        case 'md5':
                            /* See PHP's md5 - http://www.php.net/manual/en/function.md5.php */
                            $output= md5($output);
                            break;
                        case 'cdata':
                            if ($usemb) {
                                $len = mb_strlen($output,$encoding);
                                if (mb_strpos($output,'[',0,$encoding) === 0) { $output = ' '.$output; }
                                if (mb_strpos($output,']',0,$encoding) === $len) { $output = $output.' '; }
                            } else {
                                $len = strlen($output);
                                if (strpos($output,'[') === 0) { $output = ' '.$output; }
                                if (strpos($output,']') === $len) { $output = $output.' '; }
                            }
                            $output= "<![CDATA[{$output}]]>";
                            break;

                        case 'userinfo':
                            /* Returns the requested user data (input: userid) */
                            if (!empty($output)) {
                                $key = (!empty($m_val)) ? $m_val : 'username';
                                $userInfo= false;
                                if ($user= $this->modx->getObjectGraph('modUser', '{"Profile":{}}', $output)) {
                                    $userInfo= $user->get(array ('username', 'password'));
                                    if ($user->getOne('Profile')) {
                                        $userInfo= array_merge($userInfo, $user->Profile->toArray());
                                    }
                                }
                                $output = $userInfo && isset($userInfo[$key]) ? $userInfo[$key] : null;
                            }
                            break;

                        case 'isloggedin':
                            /* returns true if user is logged in */
                            $output= $this->modx->user->isAuthenticated($this->modx->context->get('key'));
                            $output= $output ? true : false;
                            break;

                        case 'isnotloggedin':
                            /* returns true if user is not logged in */
                            $output= $this->modx->user->isAuthenticated($this->modx->context->get('key'));
                            $output= $output ? false : true;
                            break;

                        case 'urlencode':
                            $output = urlencode($output);
                            break;
                        case 'urldecode':
                            $output = urldecode($output);
                            break;

                        /* Default, custom modifier (run snippet with modifier name) */
                        default:
                            /*@todo Possibility to only look for snippet names prefixed with 'filter:' */
                            /*@todo Maybe pass whole element by reference instead of token/tag/name? */
                            $params = array (
                                'input' => $output,
                                'options' => $m_val,
                                'token' => $element->_token, /* type of parent element */
                                'name' => $element->get('name'), /* name of the parent element */
                                'tag' => $element->getTag() /* complete parent tag */
                            );
                            $this->log('This modifier is custom running as snippet.');
                            $tmp = $this->modx->runSnippet($m_cmd, $params);
                            if ($tmp!='') $output = $tmp;
                            break;
                    }
                } catch (Exception $e) {
                    $this->modx->log(modX::LOG_LEVEL_ERROR,$e->getMessage());
                }
            }
        }
    }

    /**
     * Send a log message to the message logger
     * @param string $msg
     * @return void
     */
    public function log($msg) {
         if ($this->modx->getDebug() === true) {
             $this->modx->log(modX::LOG_LEVEL_DEBUG, $msg);
         }
    }
}