<?php

/**
 * PHPExcel_CachedObjectStorage_MemorySerialized
 *
 * Copyright (c) 2006 - 2015 PHPExcel
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * @category   PHPExcel
 * @package    PHPExcel_CachedObjectStorage
 * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
 * @version    ##VERSION##, ##DATE##
 */
class PHPExcel_CachedObjectStorage_MemorySerialized extends PHPExcel_CachedObjectStorage_CacheBase implements PHPExcel_CachedObjectStorage_ICache
{
  /**
   * Store cell data in cache for the current cell object if it's "dirty",
   * and the 'nullify' the current cell object
   *
   * @return void
   * @throws PHPExcel_Exception
   */
  protected function storeData()
  {
    if ($this->currentCellIsDirty && ! empty ( $this->currentObjectID ))
    {
      $this->currentObject->detach ();
      
      $this->cellCache [$this->currentObjectID] = serialize ( $this->currentObject );
      $this->currentCellIsDirty = false;
    }
    $this->currentObjectID = $this->currentObject = null;
  }
  
  /**
   * Add or Update a cell in cache identified by coordinate address
   *
   * @param string $pCoord
   *          Coordinate address of the cell to update
   * @param PHPExcel_Cell $cell
   *          Cell to update
   * @return PHPExcel_Cell
   * @throws PHPExcel_Exception
   */
  public function addCacheData($pCoord, PHPExcel_Cell $cell)
  {
    if (($pCoord !== $this->currentObjectID) && ($this->currentObjectID !== null))
    {
      $this->storeData ();
    }
    
    $this->currentObjectID = $pCoord;
    $this->currentObject = $cell;
    $this->currentCellIsDirty = true;
    
    return $cell;
  }
  
  /**
   * Get cell at a specific coordinate
   *
   * @param string $pCoord
   *          Coordinate of the cell
   * @throws PHPExcel_Exception
   * @return PHPExcel_Cell Cell that was found, or null if not found
   */
  public function getCacheData($pCoord)
  {
    if ($pCoord === $this->currentObjectID)
    {
      return $this->currentObject;
    }
    $this->storeData ();
    
    // Check if the entry that has been requested actually exists
    if (! isset ( $this->cellCache [$pCoord] ))
    {
      // Return null if requested entry doesn't exist in cache
      return null;
    }
    
    // Set current entry to the requested entry
    $this->currentObjectID = $pCoord;
    $this->currentObject = unserialize ( $this->cellCache [$pCoord] );
    // Re-attach this as the cell's parent
    $this->currentObject->attach ( $this );
    
    // Return requested entry
    return $this->currentObject;
  }
  
  /**
   * Get a list of all cell addresses currently held in cache
   *
   * @return string[]
   */
  public function getCellList()
  {
    if ($this->currentObjectID !== null)
    {
      $this->storeData ();
    }
    
    return parent::getCellList ();
  }
  
  /**
   * Clear the cell collection and disconnect from our parent
   *
   * @return void
   */
  public function unsetWorksheetCells()
  {
    if (! is_null ( $this->currentObject ))
    {
      $this->currentObject->detach ();
      $this->currentObject = $this->currentObjectID = null;
    }
    $this->cellCache = array ();
    
    // detach ourself from the worksheet, so that it can then delete this object successfully
    $this->parent = null;
  }
}
