<?php
/**
 * Class to encapsulate access to dokuwiki plugins
 *
 * @license    GPL 2 (http://www.gnu.org/licenses/gpl.html)
 * @author     Christopher Smith <chris@jalakai.co.uk>
 */

// plugin related constants
if(!defined('DOKU_PLUGIN'))  define('DOKU_PLUGIN',DOKU_INC.'lib/plugins/');

class Doku_Plugin_Controller {

  var $list_enabled = array();
  var $list_disabled = array();
  var $list_bytype = array();

  function Doku_Plugin_Controller() {
    $this->_populateMasterList();
  }

  /**
   * Returns a list of available plugins of given type
   *
   * @param $type  string, plugin_type name;
   *               the type of plugin to return,
   *               use empty string for all types
   * @param $all   bool;
   *               false to only return enabled plugins,
   *               true to return both enabled and disabled plugins
   *
   * @return       array of plugin names
   *
   * @author Andreas Gohr <andi@splitbrain.org>
   */
  function getList($type='',$all=false){

    // request the complete list
    if (!$type) {
      return $all ? array_merge($this->list_enabled,$this->list_disabled) : $this->list_enabled;
    }

    if (!isset($this->list_bytype[$type]['enabled'])) {
      $this->list_bytype[$type]['enabled'] = $this->_getListByType($type,true);
    }
    if ($all && !isset($this->list_bytype[$type]['disabled'])) {
      $this->list_bytype[$type]['disabled'] = $this->_getListByType($type,false);
    }

    return $all ? array_merge($this->list_bytype[$type]['enabled'],$this->list_bytype[$type]['disabled']) : $this->list_bytype[$type]['enabled'];
  }

  /**
   * Loads the given plugin and creates an object of it
   *
   * @author Andreas Gohr <andi@splitbrain.org>
   *
   * @param  $type string     type of plugin to load
   * @param  $name string     name of the plugin to load
   * @param  $new  bool       true to return a new instance of the plugin, false to use an already loaded instance
   * @return objectreference  the plugin object or null on failure
   */
  function &load($type,$name,$new=false){
    //we keep all loaded plugins available in global scope for reuse
    global $DOKU_PLUGINS;

    //plugin already loaded?
    if(!empty($DOKU_PLUGINS[$type][$name])){
      if ($new  && !$DOKU_PLUGINS[$type][$name]->isSingleton()) {
        $class = $type.'_plugin_'.$name;
        return class_exists($class) ? new $class : null;
      } else {
        return $DOKU_PLUGINS[$type][$name];
      }
    }

    //try to load the wanted plugin file
    list($plugin,$component) = $this->_splitName($name);
    $dir = $this->get_directory($plugin);
    $file = $component ? "$type/$component.php" : "$type.php";

    if (!include_once(DOKU_PLUGIN."$dir/$file")) {
      return null;
    }

    //construct class and instantiate
    $class = $type.'_plugin_'.$name;
    if (!class_exists($class)) return null;

    $DOKU_PLUGINS[$type][$name] = new $class;
    return $DOKU_PLUGINS[$type][$name];
  }

  function isdisabled($plugin) {
    return (array_search($plugin, $this->list_enabled) === false);
  }

  function enable($plugin) {
    if (array_search($plugin, $this->list_disabled) !== false) {
      return @unlink(DOKU_PLUGIN.$plugin.'/disabled');
    }
    return false;
  }

  function disable($plugin) {
    if (array_search($plugin, $this->list_enabled) !== false) {
      return @touch(DOKU_PLUGIN.$plugin.'/disabled');
    }
    return false;
  }

  function get_directory($plugin) {
    return $plugin;
  }

  function _populateMasterList() {
    if ($dh = opendir(DOKU_PLUGIN)) {
      while (false !== ($plugin = readdir($dh))) {
        if ($plugin == '.' || $plugin == '..' || $plugin == 'tmp') continue;
        if (is_file(DOKU_PLUGIN.$plugin)) continue;

        if (substr($plugin,-9) == '.disabled') {
          // the plugin was disabled by rc2009-01-26
          // disabling mechanism was changed back very soon again
          // to keep everything simple we just skip the plugin completely
        }elseif(@file_exists(DOKU_PLUGIN.$plugin.'/disabled')){
          $this->list_disabled[] = $plugin;
        } else {
          $this->list_enabled[] = $plugin;
        }
      }
    }
  }

  function _getListByType($type, $enabled) {
    $master_list = $enabled ? $this->list_enabled : $this->list_disabled;

    $plugins = array();
    foreach ($master_list as $plugin) {
      $dir = $this->get_directory($plugin);

      if (@file_exists(DOKU_PLUGIN."$dir/$type.php")){
        $plugins[] = $plugin;
      } else {
        if ($dp = @opendir(DOKU_PLUGIN."$dir/$type/")) {
          while (false !== ($component = readdir($dp))) {
            if (substr($component,0,1) == '.' || strtolower(substr($component, -4)) != ".php") continue;
            if (is_file(DOKU_PLUGIN."$dir/$type/$component")) {
                $plugins[] = $plugin.'_'.substr($component, 0, -4);
            }
          }
        closedir($dp);
        }
      }
    }

    return $plugins;
  }

  function _splitName($name) {
    if (array_search($name, $this->list_enabled + $this->list_disabled) === false) {
      return explode('_',$name,2);
    }

    return array($name,'');
  }

}
