<?php
/**
 * Piwik - Open source web analytics
 * 
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 * 
 * @category Piwik
 * @package Piwik
 */

/**
 * This class creates a row from a given DataTable. 
 * The row contains 
 * - for each numeric column, the returned "summary" column is the sum of all the subRows
 * - for every other column, it is ignored and will not be in the "summary row"
 * 
 * @see Piwik_DataTable_Row::sumRow() for more information on the algorithm
 * 
 * @package Piwik
 * @subpackage Piwik_DataTable
 */
class Piwik_DataTable_Row_DataTableSummary extends Piwik_DataTable_Row
{
	/**
	 * @param Piwik_DataTable  $subTable
	 */
	function __construct($subTable = null)
	{
		parent::__construct();
		
		if ($subTable !== null)
		{
			$this->sumTable($subTable);
		}
	}
	
	/**
	 * Reset this row to an empty one and sum the associated subtable again.
	 */
	public function recalculate()
	{
		$id = $this->getIdSubDataTable();
		if ($id !== null)
		{
			$subtable = Piwik_DataTable_Manager::getInstance()->getTable($id);
			$this->sumTable($subtable);
		}
	}
	
	/**
	 * Sums a tables row with this one.
	 * 
	 * @param Piwik_DataTable $table
	 */
	private function sumTable( $table )
	{
		foreach($table->getRows() as $row)
		{
			$this->sumRow($row, $enableCopyMetadata = false);
		}
	}
}
