<?php

/**

 * PHPExcel

 *

 * Copyright (c) 2006 - 2014 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 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)

 * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt	LGPL

 * @version    ##VERSION##, ##DATE##

 */





/**

 * PHPExcel_CachedObjectStorage_SQLite

 *

 * @category   PHPExcel

 * @package    PHPExcel_CachedObjectStorage

 * @copyright  Copyright (c) 2006 - 2014 PHPExcel (http://www.codeplex.com/PHPExcel)

 */

class PHPExcel_CachedObjectStorage_SQLite extends PHPExcel_CachedObjectStorage_CacheBase implements PHPExcel_CachedObjectStorage_ICache {



	/**

	 * Database table name

	 *

	 * @var string

	 */

	private $_TableName = null;



	/**

	 * Database handle

	 *

	 * @var resource

	 */

	private $_DBHandle = null;



    /**

     * 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();



			if (!$this->_DBHandle->queryExec("INSERT OR REPLACE INTO kvp_".$this->_TableName." VALUES('".$this->_currentObjectID."','".sqlite_escape_string(serialize($this->_currentObject))."')"))

				throw new PHPExcel_Exception(sqlite_error_string($this->_DBHandle->lastError()));

			$this->_currentCellIsDirty = false;

		}

		$this->_currentObjectID = $this->_currentObject = null;

	}	//	function _storeData()





    /**

     * 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;

	}	//	function addCacheData()





    /**

     * 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();



		$query = "SELECT value FROM kvp_".$this->_TableName." WHERE id='".$pCoord."'";

		$cellResultSet = $this->_DBHandle->query($query,SQLITE_ASSOC);

		if ($cellResultSet === false) {

			throw new PHPExcel_Exception(sqlite_error_string($this->_DBHandle->lastError()));

		} elseif ($cellResultSet->numRows() == 0) {

			//	Return null if requested entry doesn't exist in cache

			return null;

		}



		//	Set current entry to the requested entry

		$this->_currentObjectID = $pCoord;



		$cellResult = $cellResultSet->fetchSingle();

		$this->_currentObject = unserialize($cellResult);

        //    Re-attach this as the cell's parent

        $this->_currentObject->attach($this);



		//	Return requested entry

		return $this->_currentObject;

	}	//	function getCacheData()





	/**

	 * Is a value set for an indexed cell?

	 *

	 * @param	string		$pCoord		Coordinate address of the cell to check

	 * @return	boolean

	 */

	public function isDataSet($pCoord) {

		if ($pCoord === $this->_currentObjectID) {

			return true;

		}



		//	Check if the requested entry exists in the cache

		$query = "SELECT id FROM kvp_".$this->_TableName." WHERE id='".$pCoord."'";

		$cellResultSet = $this->_DBHandle->query($query,SQLITE_ASSOC);

		if ($cellResultSet === false) {

			throw new PHPExcel_Exception(sqlite_error_string($this->_DBHandle->lastError()));

		} elseif ($cellResultSet->numRows() == 0) {

			//	Return null if requested entry doesn't exist in cache

			return false;

		}

		return true;

	}	//	function isDataSet()





    /**

     * Delete a cell in cache identified by coordinate address

     *

     * @param	string			$pCoord		Coordinate address of the cell to delete

     * @throws	PHPExcel_Exception

     */

	public function deleteCacheData($pCoord) {

		if ($pCoord === $this->_currentObjectID) {

			$this->_currentObject->detach();

			$this->_currentObjectID = $this->_currentObject = null;

		}



		//	Check if the requested entry exists in the cache

		$query = "DELETE FROM kvp_".$this->_TableName." WHERE id='".$pCoord."'";

		if (!$this->_DBHandle->queryExec($query))

			throw new PHPExcel_Exception(sqlite_error_string($this->_DBHandle->lastError()));



		$this->_currentCellIsDirty = false;

	}	//	function deleteCacheData()





	/**

	 * Move a cell object from one address to another

	 *

	 * @param	string		$fromAddress	Current address of the cell to move

	 * @param	string		$toAddress		Destination address of the cell to move

	 * @return	boolean

	 */

	public function moveCell($fromAddress, $toAddress) {

		if ($fromAddress === $this->_currentObjectID) {

			$this->_currentObjectID = $toAddress;

		}



		$query = "DELETE FROM kvp_".$this->_TableName." WHERE id='".$toAddress."'";

		$result = $this->_DBHandle->exec($query);

		if ($result === false)

			throw new PHPExcel_Exception($this->_DBHandle->lastErrorMsg());



		$query = "UPDATE kvp_".$this->_TableName." SET id='".$toAddress."' WHERE id='".$fromAddress."'";

		$result = $this->_DBHandle->exec($query);

		if ($result === false)

			throw new PHPExcel_Exception($this->_DBHandle->lastErrorMsg());



		return TRUE;

	}	//	function moveCell()





	/**

	 * Get a list of all cell addresses currently held in cache

	 *

	 * @return	string[]

	 */

	public function getCellList() {

		if ($this->_currentObjectID !== null) {

			$this->_storeData();

		}



		$query = "SELECT id FROM kvp_".$this->_TableName;

		$cellIdsResult = $this->_DBHandle->unbufferedQuery($query,SQLITE_ASSOC);

		if ($cellIdsResult === false)

			throw new PHPExcel_Exception(sqlite_error_string($this->_DBHandle->lastError()));



		$cellKeys = array();

		foreach($cellIdsResult as $row) {

			$cellKeys[] = $row['id'];

		}



		return $cellKeys;

	}	//	function getCellList()





	/**

	 * Clone the cell collection

	 *

	 * @param	PHPExcel_Worksheet	$parent		The new worksheet

	 * @return	void

	 */

	public function copyCellCollection(PHPExcel_Worksheet $parent) {

		$this->_currentCellIsDirty;

        $this->_storeData();



		//	Get a new id for the new table name

		$tableName = str_replace('.','_',$this->_getUniqueID());

		if (!$this->_DBHandle->queryExec('CREATE TABLE kvp_'.$tableName.' (id VARCHAR(12) PRIMARY KEY, value BLOB)

													AS SELECT * FROM kvp_'.$this->_TableName))

			throw new PHPExcel_Exception(sqlite_error_string($this->_DBHandle->lastError()));



		//	Copy the existing cell cache file

		$this->_TableName = $tableName;

	}	//	function copyCellCollection()





	/**

	 * 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;

		}

		//	detach ourself from the worksheet, so that it can then delete this object successfully

		$this->_parent = null;



		//	Close down the temporary cache file

		$this->__destruct();

	}	//	function unsetWorksheetCells()





	/**

	 * Initialise this new cell collection

	 *

	 * @param	PHPExcel_Worksheet	$parent		The worksheet for this cell collection

	 */

	public function __construct(PHPExcel_Worksheet $parent) {

		parent::__construct($parent);

		if (is_null($this->_DBHandle)) {

			$this->_TableName = str_replace('.','_',$this->_getUniqueID());

			$_DBName = ':memory:';



			$this->_DBHandle = new SQLiteDatabase($_DBName);

			if ($this->_DBHandle === false)

				throw new PHPExcel_Exception(sqlite_error_string($this->_DBHandle->lastError()));

			if (!$this->_DBHandle->queryExec('CREATE TABLE kvp_'.$this->_TableName.' (id VARCHAR(12) PRIMARY KEY, value BLOB)'))

				throw new PHPExcel_Exception(sqlite_error_string($this->_DBHandle->lastError()));

		}

	}	//	function __construct()





	/**

	 * Destroy this cell collection

	 */

	public function __destruct() {

		if (!is_null($this->_DBHandle)) {

			$this->_DBHandle->queryExec('DROP TABLE kvp_'.$this->_TableName);

		}

		$this->_DBHandle = null;

	}	//	function __destruct()





	/**

	 * Identify whether the caching method is currently available

	 * Some methods are dependent on the availability of certain extensions being enabled in the PHP build

	 *

	 * @return	boolean

	 */

	public static function cacheMethodIsAvailable() {

		if (!function_exists('sqlite_open')) {

			return false;

		}



		return true;

	}



}

