<?php
/*
 * Copyright © 2003-2010, The ESUP-Portail consortium & the JA-SIG Collaborative.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright notice,
 *       this list of conditions and the following disclaimer in the documentation
 *       and/or other materials provided with the distribution.
 *     * Neither the name of the ESUP-Portail consortium & the JA-SIG
 *       Collaborative nor the names of its contributors may be used to endorse or
 *       promote products derived from this software without specific prior
 *       written permission.

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
/**
 * @file CAS/PGTStorage/pgt-file.php
 * Basic class for PGT file storage
 */

/**
 * @class PGTStorageFile
 * The PGTStorageFile class is a class for PGT file storage. An instance of 
 * this class is returned by CASClient::SetPGTStorageFile().
 *
 * @author Pascal Aubry <pascal.aubry at univ-rennes1.fr>
 *
 * @ingroup internalPGTStorageFile
 */

class PGTStorageFile extends PGTStorage
{
  /** 
   * @addtogroup internalPGTStorageFile 
   * @{ 
   */

  /**
   * a string telling where PGT's should be stored on the filesystem. Written by
   * PGTStorageFile::PGTStorageFile(), read by getPath().
   *
   * @private
   */
  var $_path;

  /**
   * This method returns the name of the directory where PGT's should be stored 
   * on the filesystem.
   *
   * @return the name of a directory (with leading and trailing '/')
   *
   * @private
   */
  function getPath()
    {
      return $this->_path;
    }

  /**
   * a string telling the format to use to store PGT's (plain or xml). Written by
   * PGTStorageFile::PGTStorageFile(), read by getFormat().
   *
   * @private
   */
  var $_format;

  /**
   * This method returns the format to use when storing PGT's on the filesystem.
   *
   * @return a string corresponding to the format used (plain or xml).
   *
   * @private
   */
  function getFormat()
    {
      return $this->_format;
    }

  // ########################################################################
  //  DEBUGGING
  // ########################################################################
  
  /**
   * This method returns an informational string giving the type of storage
   * used by the object (used for debugging purposes).
   *
   * @return an informational string.
   * @public
   */
  function getStorageType()
    {
      return "file";
    }

  /**
   * This method returns an informational string giving informations on the
   * parameters of the storage.(used for debugging purposes).
   *
   * @return an informational string.
   * @public
   */
  function getStorageInfo()
    {
      return 'path=`'.$this->getPath().'\', format=`'.$this->getFormat().'\'';
    }

  // ########################################################################
  //  CONSTRUCTOR
  // ########################################################################
  
  /**
   * The class constructor, called by CASClient::SetPGTStorageFile().
   *
   * @param $cas_parent the CASClient instance that creates the object.
   * @param $format the format used to store the PGT's (`plain' and `xml' allowed).
   * @param $path the path where the PGT's should be stored
   *
   * @public
   */
  function PGTStorageFile($cas_parent,$format,$path)
    {
      phpCAS::traceBegin();
      // call the ancestor's constructor
      $this->PGTStorage($cas_parent);

      if (empty($format) ) $format = CAS_PGT_STORAGE_FILE_DEFAULT_FORMAT;
      if (empty($path) ) $path = CAS_PGT_STORAGE_FILE_DEFAULT_PATH;

      // check that the path is an absolute path
      if (getenv("OS")=="Windows_NT"){
      	
      	 if (!preg_match('`^[a-zA-Z]:`', $path)) {
	     	phpCAS::error('an absolute path is needed for PGT storage to file');
      	}
      	
      }
      else
      {
      
      	if ( $path[0] != '/' ) {
			phpCAS::error('an absolute path is needed for PGT storage to file');
      	}

      	// store the path (with a leading and trailing '/')      
      	$path = preg_replace('|[/]*$|','/',$path);
      	$path = preg_replace('|^[/]*|','/',$path);
      }
      
      $this->_path = $path;
      // check the format and store it
      switch ($format) {
      case CAS_PGT_STORAGE_FILE_FORMAT_PLAIN:
      case CAS_PGT_STORAGE_FILE_FORMAT_XML:
	$this->_format = $format;
	break;
      default:
	phpCAS::error('unknown PGT file storage format (`'.CAS_PGT_STORAGE_FILE_FORMAT_PLAIN.'\' and `'.CAS_PGT_STORAGE_FILE_FORMAT_XML.'\' allowed)');
      }
      phpCAS::traceEnd();      
    }

  // ########################################################################
  //  INITIALIZATION
  // ########################################################################
  
  /**
   * This method is used to initialize the storage. Halts on error.
   *
   * @public
   */
  function init()
    {
      phpCAS::traceBegin();
      // if the storage has already been initialized, return immediatly
      if ( $this->isInitialized() )
	return;
      // call the ancestor's method (mark as initialized)
      parent::init();
      phpCAS::traceEnd();      
    }

  // ########################################################################
  //  PGT I/O
  // ########################################################################

  /**
   * This method returns the filename corresponding to a PGT Iou.
   *
   * @param $pgt_iou the PGT iou.
   *
   * @return a filename
   * @private
   */
  function getPGTIouFilename($pgt_iou)
    {
      phpCAS::traceBegin();
      $filename = $this->getPath().$pgt_iou.'.'.$this->getFormat();
      phpCAS::traceEnd($filename);
      return $filename;
    }
  
  /**
   * This method stores a PGT and its corresponding PGT Iou into a file. Echoes a
   * warning on error.
   *
   * @param $pgt the PGT
   * @param $pgt_iou the PGT iou
   *
   * @public
   */
  function write($pgt,$pgt_iou)
	  {
	  phpCAS::traceBegin();
	  $fname = $this->getPGTIouFilename($pgt_iou);
	  if(!file_exists($fname)){
		  if ( $f=fopen($fname,"w") ) {
			  if ( fputs($f,$pgt) === FALSE ) {
				  phpCAS::error('could not write PGT to `'.$fname.'\'');
			  }
			  fclose($f);
		  } else {
			  phpCAS::error('could not open `'.$fname.'\'');
		  }
	  }else{
		  phpCAS::error('File exists: `'.$fname.'\'');
	  }
	  phpCAS::traceEnd();      
	  }

  /**
   * This method reads a PGT corresponding to a PGT Iou and deletes the 
   * corresponding file.
   *
   * @param $pgt_iou the PGT iou
   *
   * @return the corresponding PGT, or FALSE on error
   *
   * @public
   */
  function read($pgt_iou)
	  {
	  phpCAS::traceBegin();
	  $pgt = FALSE;
	  $fname = $this->getPGTIouFilename($pgt_iou);
	  if (file_exists($fname)){
		  if ( !($f=fopen($fname,"r")) ) {
			  phpCAS::trace('could not open `'.$fname.'\'');
		  } else {
			  if ( ($pgt=fgets($f)) === FALSE ) {
				  phpCAS::trace('could not read PGT from `'.$fname.'\'');
			  } 
			  fclose($f);
		  }
		  
		  // delete the PGT file
		  @unlink($fname);
	  }else{
		  phpCAS::trace('No such file `'.$fname.'\'');
	  }
	  phpCAS::traceEnd($pgt);
	  return $pgt;
	  }
  
  /** @} */
  
}

  
?>