<?php
/**
 * Utilities for accessing the parser
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Harry Fuecks <hfuecks@gmail.com>
 * @author     Andreas Gohr <andi@splitbrain.org>
 */

if(!defined('DOKU_INC')) die('meh.');
require_once(DOKU_INC.'inc/confutils.php');
require_once(DOKU_INC.'inc/pageutils.php');
require_once(DOKU_INC.'inc/pluginutils.php');
require_once(DOKU_INC.'inc/cache.php');

/**
 * Returns the parsed Wikitext in XHTML for the given id and revision.
 *
 * If $excuse is true an explanation is returned if the file
 * wasn't found
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_wiki_xhtml($id, $rev='', $excuse=true){
    $file = wikiFN($id,$rev);
    $ret  = '';

    //ensure $id is in global $ID (needed for parsing)
    global $ID;
    $keep = $ID;
    $ID   = $id;

    if($rev){
        if(@file_exists($file)){
            $ret = p_render('xhtml',p_get_instructions(io_readWikiPage($file,$id,$rev)),$info); //no caching on old revisions
        }elseif($excuse){
            $ret = p_locale_xhtml('norev');
        }
    }else{
        if(@file_exists($file)){
            $ret = p_cached_output($file,'xhtml',$id);
        }elseif($excuse){
            $ret = p_locale_xhtml('newpage');
        }
    }

    //restore ID (just in case)
    $ID = $keep;

    return $ret;
}

/**
 * Returns starting summary for a page (e.g. the first few
 * paragraphs), marked up in XHTML.
 *
 * If $excuse is true an explanation is returned if the file
 * wasn't found
 *
 * @param string wiki page id
 * @param reference populated with page title from heading or page id
 * @deprecated
 * @author Harry Fuecks <hfuecks@gmail.com>
 */
function p_wiki_xhtml_summary($id, &$title, $rev='', $excuse=true){
    $file = wikiFN($id,$rev);
    $ret  = '';

    //ensure $id is in global $ID (needed for parsing)
    global $ID;
    $keep = $ID;
    $ID   = $id;

    if($rev){
        if(@file_exists($file)){
            //no caching on old revisions
            $ins = p_get_instructions(io_readWikiPage($file,$id,$rev));
        }elseif($excuse){
            $ret = p_locale_xhtml('norev');
            //restore ID (just in case)
            $ID = $keep;
            return $ret;
        }

    }else{

        if(@file_exists($file)){
            // The XHTML for a summary is not cached so use the instruction cache
            $ins = p_cached_instructions($file);
        }elseif($excuse){
            $ret = p_locale_xhtml('newpage');
            //restore ID (just in case)
            $ID = $keep;
            return $ret;
        }
    }

    $ret = p_render('xhtmlsummary',$ins,$info);

    if ( $info['sum_pagetitle'] ) {
        $title = $info['sum_pagetitle'];
    } else {
        $title = $id;
    }

    $ID = $keep;
    return $ret;
}

/**
 * Returns the specified local text in parsed format
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_locale_xhtml($id){
    //fetch parsed locale
    $html = p_cached_output(localeFN($id));
    return $html;
}

/**
 *     *** DEPRECATED ***
 *
 * use p_cached_output()
 *
 * Returns the given file parsed to XHTML
 *
 * Uses and creates a cachefile
 *
 * @deprecated
 * @author Andreas Gohr <andi@splitbrain.org>
 * @todo   rewrite to use mode instead of hardcoded XHTML
 */
function p_cached_xhtml($file){
    return p_cached_output($file);
}

/**
 * Returns the given file parsed into the requested output format
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 * @author Chris Smith <chris@jalakai.co.uk>
 */
function p_cached_output($file, $format='xhtml', $id='') {
    global $conf;

    $cache = new cache_renderer($id, $file, $format);
    if ($cache->useCache()) {
        $parsed = $cache->retrieveCache(false);
        if($conf['allowdebug'] && $format=='xhtml') $parsed .= "\n<!-- cachefile {$cache->cache} used -->\n";
    } else {
        $parsed = p_render($format, p_cached_instructions($file,false,$id), $info);

        if ($info['cache']) {
            $cache->storeCache($parsed);               //save cachefile
            if($conf['allowdebug'] && $format=='xhtml') $parsed .= "\n<!-- no cachefile used, but created {$cache->cache} -->\n";
        }else{
            $cache->removeCache();                     //try to delete cachefile
            if($conf['allowdebug'] && $format=='xhtml') $parsed .= "\n<!-- no cachefile used, caching forbidden -->\n";
        }
    }

    return $parsed;
}

/**
 * Returns the render instructions for a file
 *
 * Uses and creates a serialized cache file
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_cached_instructions($file,$cacheonly=false,$id='') {
    global $conf;
    static $run = null;
    if(is_null($run)) $run = array();

    $cache = new cache_instructions($id, $file);

    if ($cacheonly || $cache->useCache() || isset($run[$file])) {
        return $cache->retrieveCache();
    } else if (@file_exists($file)) {
        // no cache - do some work
        $ins = p_get_instructions(io_readWikiPage($file,$id));
        if ($cache->storeCache($ins)) {
            $run[$file] = true; // we won't rebuild these instructions in the same run again
        } else {
            msg('Unable to save cache file. Hint: disk full; file permissions; safe_mode setting.',-1);
        }
        return $ins;
    }

    return null;
}

/**
 * turns a page into a list of instructions
 *
 * @author Harry Fuecks <hfuecks@gmail.com>
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_get_instructions($text){

    $modes = p_get_parsermodes();

    // Create the parser
    $Parser = & new Doku_Parser();

    // Add the Handler
    $Parser->Handler = & new Doku_Handler();

    //add modes to parser
    foreach($modes as $mode){
        $Parser->addMode($mode['mode'],$mode['obj']);
    }

    // Do the parsing
    trigger_event('PARSER_WIKITEXT_PREPROCESS', $text);
    $p = $Parser->parse($text);
    //  dbg($p);
    return $p;
}

/**
 * returns the metadata of a page
 *
 * @author Esther Brunner <esther@kaffeehaus.ch>
 */
function p_get_metadata($id, $key=false, $render=false){
    global $ID, $INFO, $cache_metadata;

    // cache the current page
    // Benchmarking shows the current page's metadata is generally the only page metadata
    // accessed several times. This may catch a few other pages, but that shouldn't be an issue.
    $cache = ($ID == $id);
    $meta = p_read_metadata($id, $cache);

    // metadata has never been rendered before - do it! (but not for non-existent pages)
    if ($render && !isset($meta['current']['description']['abstract']) && page_exists($id)){
        $meta = p_render_metadata($id, $meta);
        io_saveFile(metaFN($id, '.meta'), serialize($meta));

        // sync cached copies, including $INFO metadata
        if (!empty($cache_metadata[$id])) $cache_metadata[$id] = $meta;
        if (!empty($INFO) && ($id == $INFO['id'])) { $INFO['meta'] = $meta['current']; }
    }

    // filter by $key
    if ($key){
        list($key, $subkey) = explode(' ', $key, 2);
        $subkey = trim($subkey);

        if ($subkey) {
            return isset($meta['current'][$key][$subkey]) ? $meta['current'][$key][$subkey] : null;
        }

        return isset($meta['current'][$key]) ? $meta['current'][$key] : null;
    }

    return $meta['current'];
}

/**
 * sets metadata elements of a page
 *
 * @author Esther Brunner <esther@kaffeehaus.ch>
 */
function p_set_metadata($id, $data, $render=false, $persistent=true){
    if (!is_array($data)) return false;

    global $ID;

    // cache the current page
    $cache = ($ID == $id);
    $orig = p_read_metadata($id, $cache);

    // render metadata first?
    $meta = $render ? p_render_metadata($id, $orig) : $orig;

    // now add the passed metadata
    $protected = array('description', 'date', 'contributor');
    foreach ($data as $key => $value){

        // be careful with sub-arrays of $meta['relation']
        if ($key == 'relation'){

            foreach ($value as $subkey => $subvalue){
                $meta['current'][$key][$subkey] = !empty($meta['current'][$key][$subkey]) ? array_merge($meta['current'][$key][$subkey], $subvalue) : $subvalue;
                if ($persistent)
                    $meta['persistent'][$key][$subkey] = !empty($meta['persistent'][$key][$subkey]) ? array_merge($meta['persistent'][$key][$subkey], $subvalue) : $subvalue;
            }

            // be careful with some senisitive arrays of $meta
        } elseif (in_array($key, $protected)){

            // these keys, must have subkeys - a legitimate value must be an array
            if (is_array($value)) {
                $meta['current'][$key] = !empty($meta['current'][$key]) ? array_merge($meta['current'][$key],$value) : $value;

                if ($persistent) {
                    $meta['persistent'][$key] = !empty($meta['persistent'][$key]) ? array_merge($meta['persistent'][$key],$value) : $value;
                }
            }

            // no special treatment for the rest
        } else {
            $meta['current'][$key] = $value;
            if ($persistent) $meta['persistent'][$key] = $value;
        }
    }

    // save only if metadata changed
    if ($meta == $orig) return true;

    // sync cached copies, including $INFO metadata
    global $cache_metadata, $INFO;

    if (!empty($cache_metadata[$id])) $cache_metadata[$id] = $meta;
    if (!empty($INFO) && ($id == $INFO['id'])) { $INFO['meta'] = $meta['current']; }

    return io_saveFile(metaFN($id, '.meta'), serialize($meta));
}

/**
 * Purges the non-persistant part of the meta data
 * used on page deletion
 *
 * @author Michael Klier <chi@chimeric.de>
 */
function p_purge_metadata($id) {
    $metafn = metaFN('id', '.meta');
    $meta   = p_read_metadata($id);
    foreach($meta['current'] as $key => $value) {
        if(is_array($meta[$key])) {
            $meta['current'][$key] = array();
        } else {
            $meta['current'][$key] = '';
        }
    }
    return io_saveFile(metaFN($id, '.meta'), serialize($meta));
}

/**
 * read the metadata from source/cache for $id
 * (internal use only - called by p_get_metadata & p_set_metadata)
 *
 * this function also converts the metadata from the original format to
 * the current format ('current' & 'persistent' arrays)
 *
 * @author   Christopher Smith <chris@jalakai.co.uk>
 *
 * @param    string   $id      absolute wiki page id
 * @param    bool     $cache   whether or not to cache metadata in memory
 *                             (only use for metadata likely to be accessed several times)
 *
 * @return   array             metadata
 */
function p_read_metadata($id,$cache=false) {
    global $cache_metadata;

    if (isset($cache_metadata[(string)$id])) return $cache_metadata[(string)$id];

    $file = metaFN($id, '.meta');
    $meta = @file_exists($file) ? unserialize(io_readFile($file, false)) : array('current'=>array(),'persistent'=>array());

    // convert $meta from old format to new (current+persistent) format
    if (!isset($meta['current'])) {
        $meta = array('current'=>$meta,'persistent'=>$meta);

        // remove non-persistent keys
        unset($meta['persistent']['title']);
        unset($meta['persistent']['description']['abstract']);
        unset($meta['persistent']['description']['tableofcontents']);
        unset($meta['persistent']['relation']['haspart']);
        unset($meta['persistent']['relation']['references']);
        unset($meta['persistent']['date']['valid']);

        if (empty($meta['persistent']['description'])) unset($meta['persistent']['description']);
        if (empty($meta['persistent']['relation'])) unset($meta['persistent']['relation']);
        if (empty($meta['persistent']['date'])) unset($meta['persistent']['date']);

        // save converted metadata
        io_saveFile($file, serialize($meta));
    }

    if ($cache) {
        $cache_metadata[(string)$id] = $meta;
    }

    return $meta;
}

/**
 * renders the metadata of a page
 *
 * @author Esther Brunner <esther@kaffeehaus.ch>
 */
function p_render_metadata($id, $orig){
    // make sure the correct ID is in global ID
    global $ID;
    $keep = $ID;
    $ID   = $id;

    // add an extra key for the event - to tell event handlers the page whose metadata this is
    $orig['page'] = $id;
    $evt = new Doku_Event('PARSER_METADATA_RENDER', $orig);
    if ($evt->advise_before()) {

        require_once DOKU_INC."inc/parser/metadata.php";

        // get instructions
        $instructions = p_cached_instructions(wikiFN($id),false,$id);
        if(is_null($instructions)){
            $ID = $keep;
            return null; // something went wrong with the instructions
        }

        // set up the renderer
        $renderer = & new Doku_Renderer_metadata();
        $renderer->meta = $orig['current'];
        $renderer->persistent = $orig['persistent'];

        // loop through the instructions
        foreach ($instructions as $instruction){
            // execute the callback against the renderer
            call_user_func_array(array(&$renderer, $instruction[0]), $instruction[1]);
        }

        $evt->result = array('current'=>$renderer->meta,'persistent'=>$renderer->persistent);
    }
    $evt->advise_after();

    $ID = $keep;
    return $evt->result;
}

/**
 * returns all available parser syntax modes in correct order
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_get_parsermodes(){
    global $conf;

    //reuse old data
    static $modes = null;
    if($modes != null){
        return $modes;
    }

    //import parser classes and mode definitions
    require_once DOKU_INC . 'inc/parser/parser.php';

    // we now collect all syntax modes and their objects, then they will
    // be sorted and added to the parser in correct order
    $modes = array();

    // add syntax plugins
    $pluginlist = plugin_list('syntax');
    if(count($pluginlist)){
        global $PARSER_MODES;
        $obj = null;
        foreach($pluginlist as $p){
            if(!$obj =& plugin_load('syntax',$p)) continue; //attempt to load plugin into $obj
            $PARSER_MODES[$obj->getType()][] = "plugin_$p"; //register mode type
            //add to modes
            $modes[] = array(
                    'sort' => $obj->getSort(),
                    'mode' => "plugin_$p",
                    'obj'  => $obj,
                    );
            unset($obj); //remove the reference
        }
    }

    // add default modes
    $std_modes = array('listblock','preformatted','notoc','nocache',
            'header','table','linebreak','footnote','hr',
            'unformatted','php','html','code','file','quote',
            'internallink','rss','media','externallink',
            'emaillink','windowssharelink','eol');
    if($conf['typography']){
        $std_modes[] = 'quotes';
        $std_modes[] = 'multiplyentity';
    }
    foreach($std_modes as $m){
        $class = "Doku_Parser_Mode_$m";
        $obj   = new $class();
        $modes[] = array(
                'sort' => $obj->getSort(),
                'mode' => $m,
                'obj'  => $obj
                );
    }

    // add formatting modes
    $fmt_modes = array('strong','emphasis','underline','monospace',
            'subscript','superscript','deleted');
    foreach($fmt_modes as $m){
        $obj   = new Doku_Parser_Mode_formatting($m);
        $modes[] = array(
                'sort' => $obj->getSort(),
                'mode' => $m,
                'obj'  => $obj
                );
    }

    // add modes which need files
    $obj     = new Doku_Parser_Mode_smiley(array_keys(getSmileys()));
    $modes[] = array('sort' => $obj->getSort(), 'mode' => 'smiley','obj'  => $obj );
    $obj     = new Doku_Parser_Mode_acronym(array_keys(getAcronyms()));
    $modes[] = array('sort' => $obj->getSort(), 'mode' => 'acronym','obj'  => $obj );
    $obj     = new Doku_Parser_Mode_entity(array_keys(getEntities()));
    $modes[] = array('sort' => $obj->getSort(), 'mode' => 'entity','obj'  => $obj );

    // add optional camelcase mode
    if($conf['camelcase']){
        $obj     = new Doku_Parser_Mode_camelcaselink();
        $modes[] = array('sort' => $obj->getSort(), 'mode' => 'camelcaselink','obj'  => $obj );
    }

    //sort modes
    usort($modes,'p_sort_modes');

    return $modes;
}

/**
 * Callback function for usort
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_sort_modes($a, $b){
    if($a['sort'] == $b['sort']) return 0;
    return ($a['sort'] < $b['sort']) ? -1 : 1;
}

/**
 * Renders a list of instruction to the specified output mode
 *
 * In the $info array are informations from the renderer returned
 *
 * @author Harry Fuecks <hfuecks@gmail.com>
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_render($mode,$instructions,&$info){
    if(is_null($instructions)) return '';

    $Renderer =& p_get_renderer($mode);
    if (is_null($Renderer)) return null;

    $Renderer->reset();

    $Renderer->smileys = getSmileys();
    $Renderer->entities = getEntities();
    $Renderer->acronyms = getAcronyms();
    $Renderer->interwiki = getInterwiki();

    // Loop through the instructions
    foreach ( $instructions as $instruction ) {
        // Execute the callback against the Renderer
        call_user_func_array(array(&$Renderer, $instruction[0]),$instruction[1]);
    }

    //set info array
    $info = $Renderer->info;

    // Post process and return the output
    $data = array($mode,& $Renderer->doc);
    trigger_event('RENDERER_CONTENT_POSTPROCESS',$data);
    return $Renderer->doc;
}

function & p_get_renderer($mode) {
    global $conf, $plugin_controller;

    $rname = !empty($conf['renderer_'.$mode]) ? $conf['renderer_'.$mode] : $mode;

    // try default renderer first:
    $file = DOKU_INC."inc/parser/$rname.php";
    if(@file_exists($file)){
        require_once $file;
        $rclass = "Doku_Renderer_$rname";

        if ( !class_exists($rclass) ) {
            trigger_error("Unable to resolve render class $rclass",E_USER_WARNING);
            msg("Renderer '$rname' for $mode not valid",-1);
            return null;
        }
        $Renderer = & new $rclass();
    }else{
        // Maybe a plugin/component is available?
        list($plugin, $component) = $plugin_controller->_splitName($rname);
        if (!$plugin_controller->isdisabled($plugin)){
            $Renderer =& $plugin_controller->load('renderer',$rname, true);
        }

        if(is_null($Renderer)){
            msg("No renderer '$rname' found for mode '$mode'",-1);
            return null;
        }
    }

    return $Renderer;
}

/**
 * Gets the first heading from a file
 *
 * @param   string   $id       dokuwiki page id
 * @param   bool     $render   rerender if first heading not known
 *                             default: true  -- must be set to false for calls from the metadata renderer to
 *                                               protects against loops and excessive resource usage when pages
 *                                               for which only a first heading is required will attempt to
 *                                               render metadata for all the pages for which they require first
 *                                               headings ... and so on.
 *
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_get_first_heading($id, $render=true){
    return p_get_metadata($id,'title',$render);
}

/**
 * Wrapper for GeSHi Code Highlighter, provides caching of its output
 *
 * @param  string   $code       source code to be highlighted
 * @param  string   $language   language to provide highlighting
 * @param  string   $wrapper    html element to wrap the returned highlighted text
 *
 * @author Christopher Smith <chris@jalakai.co.uk>
 * @author Andreas Gohr <andi@splitbrain.org>
 */
function p_xhtml_cached_geshi($code, $language, $wrapper='pre') {
    global $conf, $config_cascade;
    $language = strtolower($language);

    // remove any leading or trailing blank lines
    $code = preg_replace('/^\s*?\n|\s*?\n$/','',$code);

    $cache = getCacheName($language.$code,".code");
    $ctime = @filemtime($cache);
    if($ctime && !$_REQUEST['purge'] &&
            $ctime > filemtime('/usr/share/php-geshi/geshi.php') &&                 // geshi changed
            $ctime > @filemtime('/usr/share/php-geshi/geshi/'.$language.'.php') &&  // language syntax definition changed
            $ctime > filemtime(reset($config_cascade['main']['default']))){ // dokuwiki changed
        $highlighted_code = io_readFile($cache, false);

    } else {

        require_once('/usr/share/php-geshi/geshi.php');

        $geshi = new GeSHi($code, $language, '/usr/share/php-geshi/geshi');
        $geshi->set_encoding('utf-8');
        $geshi->enable_classes();
        $geshi->set_header_type(GESHI_HEADER_PRE);
        $geshi->set_link_target($conf['target']['extern']);

        // remove GeSHi's wrapper element (we'll replace it with our own later)
        // we need to use a GeSHi wrapper to avoid <BR> throughout the highlighted text
        $highlighted_code = trim(preg_replace('!^<pre[^>]*>|</pre>$!','',$geshi->parse_code()),"\n\r");
        io_saveFile($cache,$highlighted_code);
    }

    // add a wrapper element if required
    if ($wrapper) {
        return "<$wrapper class=\"code $language\">$highlighted_code</$wrapper>";
    } else {
        return $highlighted_code;
    }
}