<?php
/**
 * Translation Plugin: Simple multilanguage plugin
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Andreas Gohr <andi@splitbrain.org>
 */

// must be run within Dokuwiki
if(!defined('DOKU_INC')) die();

class helper_plugin_translation extends DokuWiki_Plugin {
    var $trans       = array();
    var $tns         = '';
    var $defaultlang = '';
    var $LN          = array(); // hold native names
    var $opts        = array(); // display options

    /**
     * Initialize
     */
    function helper_plugin_translation(){
        global $conf;
        require_once(DOKU_INC.'inc/pageutils.php');
        require_once(DOKU_INC.'inc/utf8.php');

        // load wanted translation into array
        $this->trans = strtolower(str_replace(',',' ',$this->getConf('translations')));
        $this->trans = array_unique(array_filter(explode(' ',$this->trans)));
        sort($this->trans);

        // load language names
        $this->LN = confToHash(dirname(__FILE__).'/lang/langnames.txt');

        // display options
        $this->opts = $this->getConf('display');
        $this->opts = explode(',',$this->opts);
        $this->opts = array_map('trim',$this->opts);
        $this->opts = array_fill_keys($this->opts, true);

        // get default translation
        if(!$conf['lang_before_translation']){
            $dfl = $conf['lang'];
        } else {
            $dfl = $conf['lang_before_translation'];
        }
        if(in_array($dfl,$this->trans)){
            $this->defaultlang = $dfl;
        }else{
            $this->defaultlang = '';
            array_unshift($this->trans,'');
        }

        $this->tns = cleanID($this->getConf('translationns'));
        if($this->tns) $this->tns .= ':';
    }

    /**
     * Check if the given ID is a translation and return the language code.
     */
    function getLangPart($id){
        list($lng) = $this->getTransParts($id);
        return $lng;
    }

    /**
     * Check if the given ID is a translation and return the language code and
     * the id part.
     */
    function getTransParts($id){
        $rx = '/^'.$this->tns.'('.join('|',$this->trans).'):(.*)/';
        if(preg_match($rx,$id,$match)){
            return array($match[1],$match[2]);
        }
        return array('',$id);
    }

    /**
     * Returns the browser language if it matches with one of the configured
     * languages
     */
    function getBrowserLang(){
        $rx = '/(^|,|:|;|-)('.join('|',$this->trans).')($|,|:|;|-)/i';
        if(preg_match($rx,$_SERVER['HTTP_ACCEPT_LANGUAGE'],$match)){
            return strtolower($match[2]);
        }
        return false;
    }

    /**
     * Returns the ID and name to the wanted translation, empty
     * $lng is default lang
     */
    function buildTransID($lng,$idpart){
        global $conf;
        if($lng){
            $link = ':'.$this->tns.$lng.':'.$idpart;
            $name = $lng;
        }else{
            $link = ':'.$this->tns.$idpart;
            $name = $this->realLC('');
        }
        return array($link,$name);
    }

    /**
     * Returns the real language code, even when an empty one is given
     * (eg. resolves th default language)
     */
    function realLC($lc){
        global $conf;
        if($lc){
            return $lc;
        }elseif(!$conf['lang_before_translation']){
            return $conf['lang'];
        } else {
            return $conf['lang_before_translation'];
        }
    }

    /**
     * Check if current ID should be translated and any GUI
     * should be shown
     */
    function istranslatable($id,$checkact=true){
        global $ACT;

        if($checkact && $ACT != 'show') return false;
        if($this->tns && strpos($id,$this->tns) !== 0) return false;
        $skiptrans = trim($this->getConf('skiptrans'));
        if($skiptrans &&  preg_match('/'.$skiptrans.'/ui',':'.$id)) return false;
        $meta = p_get_metadata($id);
        if($meta['plugin']['translation']['notrans']) return false;

        return true;
    }

    /**
     * Return the (localized) about link
     */
    function showAbout() {
        global $ID;
        global $conf;
        global $INFO;

        $curlc = $this->getLangPart($ID);

        $about = $this->getConf('about');
        if($this->getConf('localabout')){
            list($lc,$idpart) = $this->getTransParts($about);
            list($about,$name) = $this->buildTransID($curlc,$idpart);
            $about = cleanID($about);
        }

        $out = '';
        $out .= '<sup>';
        $out .= html_wikilink($about,'?');
        $out .= '</sup>';

        return $out;
    }

    /**
     * Returns a list of (lc => link) for all existing translations of a page
     *
     * @param $id
     * @return array
     */
    function getAvailableTranslations($id){
        $result = array();

        list($lc,$idpart) = $this->getTransParts($id);
        $lang = $this->realLC($lc);

        foreach($this->trans as $t){
            if($t == $lc) continue; //skip self
            list($link, $name) = $this->buildTransID($t, $idpart);
            if(page_exists($link)){
                $result[$name] = $link;
            }
        }

        return $result;
    }

    /**
     * Displays the available and configured translations. Needs to be placed in the template.
     */
    function showTranslations(){
        global $ID;
        global $conf;
        global $INFO;

        if(!$this->istranslatable($ID)) return;
        $this->checkage();

        list($lc,$idpart) = $this->getTransParts($ID);
        $lang = $this->realLC($lc);


        $out  = '<div class="plugin_translation">';

        //show title and about
        if (isset($this->opts['title'])){
            $out .= '<span>'.$this->getLang('translations');
            if ($this->getConf('about')) $out .= $this->showAbout();
            $out .= ':</span> ';
            if(isset($this->opts['twolines'])) $out .= '<br />';
        }

        // open wrapper
        if($this->getConf('dropdown')){
            // select needs its own styling
            if($INFO['exists']){
                $class = 'wikilink1';
            }else{
                $class = 'wikilink2';
            }
            if(isset($this->opts['flag'])){
                $flag   = DOKU_BASE.'lib/plugins/translation/flags/'.hsc($lang).'.gif';
            }
            if($conf['userewrite']){
                $action = wl();
            }else{
                $action = script();
            }

            $out .= '<form action="'.$action.'" id="translation__dropdown">';
            if($flag) $out .= '<img src="'.$flag.'" alt="'.hsc($lang).'" height="11" class="'.$class.'" /> ';
            $out .= '<select name="id" class="'.$class.'">';
        }else{
            $out .= '<ul>';
        }

        // insert items
        foreach($this->trans as $t){
            $out .= $this->getTransItem($t, $idpart);
        }

        // close wrapper
        if($this->getConf('dropdown')){
            $out .= '</select>';
            $out .= '<input name="go" type="submit" value="&rarr;" />';
            $out .= '</form>';
        }else{
            $out .= '</ul>';
        }

        // show about if not already shown
        if (!isset($this->opts['title']) && $this->getConf('about')) {
            $out .= '&nbsp';
            $out .= $this->showAbout();
        }

        $out .= '</div>';

        return $out;
    }

    /**
     * Return the local name
     *
     * @param $lang
     * @return string
     */
    function getLocalName($lang){
        if ($this->LN[$lang]){
            return $this->LN[$lang];
        }
        return $lang;
    }

    /**
     * Create the link or option for a single translation
     *
     * @param $lc string      The language code
     * @param $idpart string  The ID of the translated page
     * @returns string        The item
     */
    function getTransItem($lc, $idpart) {
        global $ID;
        global $conf;

        list($link,$lang) = $this->buildTransID($lc,$idpart);
        $link = cleanID($link);

        // class
        if(page_exists($link,'',false)){
            $class = 'wikilink1';
        }else{
            $class = 'wikilink2';
        }

        // local language name
        $localname = $this->getLocalName($lang);

        // current?
        if($ID == $link){
            $sel    = ' selected="selected"';
            $class .= ' cur';
        }else{
            $sel    = '';
        }

        // flag
        if(isset($this->opts['flag'])){
            $flag   = DOKU_BASE.'lib/plugins/translation/flags/'.hsc($lang).'.gif';
            $style  = ' style="background-image: url(\''.$flag.'\')"';
            $class .= ' flag';
        }

        // what to display as name
        if(isset($this->opts['name'])){
            $display = hsc($localname);
            if(isset($this->opts['langcode'])) $display .= ' ('.hsc($lang).')';
        }elseif(isset($this->opts['langcode'])){
            $display = hsc($lang);
        }else{
            $display = '&nbsp;';
        }

        // prepare output
        $out = '';
        if($this->getConf('dropdown')){
            if($conf['useslash']) $link = str_replace(':', '/', $link);

            $out .= '<option class="'.$class.'" title="'.hsc($localname).'" value="'.$link.'"'.$sel.$style.'>';
            $out .= $display;
            $out .= '</option>';
        }else{
            $out .= '<li><div class="li">';
            $out .= '<a href="'.wl($link).'" class="'.$class.'" title="'.hsc($localname).'">';
            if($flag) $out .= '<img src="'.$flag.'" alt="'.hsc($lang).'" height="11" />';
            $out .= $display;
            $out .= '</a>';
            $out .= '</div></li>';
        }

        return $out;
    }

    /**
     * Checks if the current page is a translation of a page
     * in the default language. Displays a notice when it is
     * older than the original page. Tries to lin to a diff
     * with changes on the original since the translation
     */
    function checkage(){
        global $ID;
        global $INFO;
        if(!$this->getConf('checkage')) return;
        if(!$INFO['exists']) return;
        $lng = $this->getLangPart($ID);
        if($lng == $this->defaultlang) return;

        $rx = '/^'.$this->tns.'(('.join('|',$this->trans).'):)?/';
        $idpart = preg_replace($rx,'',$ID);

        // compare modification times
        list($orig,$name) = $this->buildTransID($this->defaultlang,$idpart);
        $origfn = wikiFN($orig);
        if($INFO['lastmod'] >= @filemtime($origfn) ) return;

        // get revision from before translation
        $orev = 0;
        $revs = getRevisions($orig,0,100);
        foreach($revs as $rev){
            if($rev < $INFO['lastmod']){
                $orev = $rev;
                break;
            }
        }

        // see if the found revision still exists
        if($orev && !page_exists($orig,$orev)) $orev=0;

        // build the message and display it
        $orig = cleanID($orig);
        $msg = sprintf($this->getLang('outdated'),wl($orig));
        if($orev){
            $msg .= sprintf(' '.$this->getLang('diff'),
                    wl($orig,array('do'=>'diff','rev'=>$orev)));
        }

        echo '<div class="notify">'.$msg.'</div>';
    }
}