<?php

  class mw_xml_data_handler{

    public $xml_data;
    public $data_path;
    public $data_path_handler;
    public $last_index;

    public function mw_xml_data_handler($xml_data, $data_path){
      $this->xml_data = $xml_data;
      $this->data_path = $data_path.(substr($data_path, -1) != "/" ? "/" : "");
    }

    public function get_data($data_id){
      if(file_exists($this->xml_data->host().$this->xml_data->base().$this->data_path.$data_id.".xml")){
        return $this->xml_data->get_data($this->data_path, $data_id);
      }
      return false;
    }

    public function open_data($FETCH = true){
      clearstatcache();
      $INDEX_OK = false;
      if($this->xml_data->host() && $this->xml_data->base() && $this->data_path){
        if(is_dir($this->xml_data->host().$this->xml_data->base().$this->data_path) && is_writable($this->xml_data->host().$this->xml_data->base().$this->data_path)){
          if(!file_exists($this->xml_data->host().$this->xml_data->base().$this->data_path.".index")){
            if($fh = @fopen($this->xml_data->host().$this->xml_data->base().$this->data_path.".index", "w+")){
              if(@fwrite($fh, "0")){
                $this->last_index = 0;
                @fclose($fh);
                $INDEX_OK = true;
              }
              else @fclose($fh);
            }
          }
          else{
            if(($this->buffer = @file_get_contents($this->xml_data->host().$this->xml_data->base().$this->data_path.".index")) !== false){
              if(preg_match("/^[0-9]+$/", $this->buffer)){
                $this->last_index = (int)$this->buffer;
                $INDEX_OK = true;
              }
            }
          }
        }
      }
      if($INDEX_OK){
        if($FETCH){
          if($this->data_path_handler = @opendir($this->xml_data->host().$this->xml_data->base().$this->data_path)){
            return true;
          }
          else{
            $this->close_data();
            return null;
          }
        }
        else return true;
      }
      else{
        $this->close_data();
        return null;
      }
    }

    public function fetch_assoc(){
      if($this->data_path_handler){
        $FORMAT_OK = false;
        while(!$FORMAT_OK && ($data_file = @readdir($this->data_path_handler)) !== false){
          if(substr($data_file, 0, 1) != "." && substr($data_file, -4) == ".xml") $FORMAT_OK = true;
        }
        if($FORMAT_OK) return $this->xml_data->get_data($this->data_path, substr($data_file, 0, -4));
      }
      return false;
    }

    public function add_data($data, $index = null){
      if(!isset($index)) $index = $this->inc_index();
      if(isset($index)){
        if(is_array($data)) return $this->xml_data->add_data($this->data_path, $index, $data);
      }
      return null;
    }

    public function inc_index(){
      clearstatcache();
      if(isset($this->last_index)){
        $index = $this->last_index + 1;
        if($fh = @fopen($this->xml_data->host().$this->xml_data->base().$this->data_path.".index", "w+")){
          if(@fwrite($fh, (string)$index)){
            $this->last_index = $index;
            @fclose($fh);
            return $index;
          }
          else @fclose($fh);
        }
      }
      return null;
    }

    public function set_data($data_file, $data){
      if(preg_match("/^[0-9]+\.xml$/", $data_file)){
        if(is_writable($this->xml_data->host().$this->xml_data->base().$this->data_path.$data_file)){
          if(is_array($data)){
            return $this->xml_data->set_data($this->data_path, substr($data_file, 0, -4), $data);
          }
        }
      }
      return null;
    }

    public function del_data($data_file){
      if(preg_match("/^[0-9]+\.xml$/", $data_file)){
        if(is_file($this->xml_data->host().$this->xml_data->base().$this->data_path.$data_file)){
          return $this->xml_data->del_data($this->data_path, substr($data_file, 0, -4));
        }
      }
      return null;
    }

    public function close_data(){
      $this->data_path= null;
      if($this->data_path_handler) @closedir($this->data_path_handler);
      $this->last_index = null;
    }

  }