<?php

$GLOBALS['_SKELETON_FileDB_Handler'] = null;

stream_wrapper_register('filedb', 'FileDB_Stream')
 or die('Failed to register protocol filedb');

class FileDB_Stream {
	
	var $_blockSize;
	var $FileDB;
	var $position;
	var $id_file;
	var $size;
	
	
    function setHandler(&$Handler)
    {
        if ($isHandler = (is_a($Handler, 'FileDB') || is_a($Handler, 'ImageDB')) ) {
            $GLOBALS['_SKELETON_FileDB_Handler'] = $Handler;
        }
        return $isHandler;
    }
    
    function getHandler()
    {
        if (is_a($GLOBALS['_SKELETON_FileDB_Handler'], 'FileDB') ||
        	 is_a($GLOBALS['_SKELETON_FileDB_Handler'], 'ImageDB') ) {
            return $GLOBALS['_SKELETON_FileDB_Handler'];
        }
        return null;
    }
    	
	
	function open(&$FileDB, $id)
	{
		FileDB_Stream::setHandler(&$FileDB);
		return fopen('filedb://'.$id, 'r+');
	}
	
  
	function stream_open($path, $mode, $options, &$opened_path)
	{
        if (!$this->FileDB = FileDB_Stream::getHandler()) {
            return false;
        }
        
		$this->_blockSize = $this->FileDB->blockSize;
		$url              = parse_url($path);
		$this->id_file    = $url['host'];
		$this->position   = 0;
		$arr              = $this->FileDB->getArr($this->id_file, 'id');
		$this->size       = $arr['size'];
		$this->mtime      = $arr['changed_uts'];
		return true;
	}
   
   function stream_read($count)
   {
	$fileDataTable = 'tbl'.$this->FileDB->fileDataTable;   	
    $part = floor($this->position / $this->_blockSize );
    $partRange = $this->position  % $this->_blockSize ;   	
    $ret = '';
	do {
	    $sql = "SELECT data FROM {$this->FileDB->db->$fileDataTable} WHERE id_file = '{$this->id_file}' ORDER BY part ASC LIMIT $part, 1";
	    $data = $this->FileDB->db->queryOne($sql);
		if (PEAR::isError($data)) {
        	$GLOBALS['_DEBUG']['level'] = D_ECHO;
        	dump($data->getUserInfo(), 'stream_read error');
        	exit();
		}

	    if ($partRange || $this->_blockSize > ($partRange + $count - strlen($ret)) ){
	        $data = substr($data, $partRange, $count - strlen($ret) );
	    }
	    $ret .= $data;
	    $part++; 
	    $partRange = 0;
	}while (!empty($data) && $count > strlen($ret) && strlen($ret) + $this->position < $this->size  );
       $this->position += strlen($ret);
       return $ret;
   }
   
   function stream_seek($offset, $whence)
   {
       switch ($whence) {
           case SEEK_SET:
               if ($offset < $this->size && $offset >= 0) {
                     $this->position = $offset;
                     return true;
               } else {
                     return false;
               }
               break;
              
           case SEEK_CUR:
               if ($offset >= 0) {
                     $this->position += $offset;
                     return true;
               } else {
                     return false;
               }
               break;
              
           case SEEK_END:
               if ($this->size + $offset >= 0) {
                     $this->position = $this->size + $offset;
                     return true;
               } else {
                     return false;
               }
               break;
              
           default:
               return false;
       }
   }
  
	function stream_tell()
	{
		return $this->position;
	}
	
	function stream_eof()
	{
		return $this->position >= $this->size;
	}
	
	function stream_flush()
	{
	    return true;
	}   
	
	function stream_stat()
	{
	   	return array('size' => $this->size, 'ino' => $this->id_file, 'mtime' => $this->mtime);
	}
	
	function stream_write($data)
	{
		return 0;
	}
	
	function stream_close()
	{
		return true;
	}

}