<?php
/**
 * Piwik - Open source web analytics
 * 
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 * @version $Id: Pattern.php 6353 2012-05-28 17:29:23Z SteveG $
 * 
 * @category Piwik
 * @package Piwik
 */

/**
 * Delete all rows for which the given $columnToFilter do not contain the $patternToSearch
 * This filter is to be used on columns containing strings. 
 * Example: from the keyword report, keep only the rows for which the label contains "piwik"
 * 
 * @package Piwik
 * @subpackage Piwik_DataTable
 */
class Piwik_DataTable_Filter_Pattern extends Piwik_DataTable_Filter
{
	private $columnToFilter;
	private $patternToSearch;
	private $patternToSearchQuoted;
    private $invertedMatch;

	/**
	 * @param Piwik_DataTable  $table
	 * @param string           $columnToFilter
	 * @param string           $patternToSearch
	 * @param bool             $invertedMatch
	 */
	public function __construct( $table, $columnToFilter, $patternToSearch, $invertedMatch = false )
	{
		parent::__construct($table);
		$this->patternToSearch = $patternToSearch;
		$this->patternToSearchQuoted = self::getPatternQuoted($patternToSearch);
		$this->columnToFilter = $columnToFilter;
        $this->invertedMatch = $invertedMatch;
	}

	/**
	 * Helper method to return the given pattern quoted
	 *
	 * @param string  $pattern
	 * @return string
	 */
	static public function getPatternQuoted( $pattern )
	{
		return '/'. str_replace('/', '\/', $pattern) .'/';
	}

	/**
	 * Performs case insensitive match
	 *
	 * @param string  $pattern
	 * @param string  $patternQuoted
	 * @param string  $string
	 * @param bool    $invertedMatch
	 * @return int
	 */
	static public function match($pattern, $patternQuoted, $string, $invertedMatch)
	{
		return @preg_match($patternQuoted . "i",  $string) == 1 ^ $invertedMatch;
	}

	/**
	 * @param Piwik_DataTable  $table
	 */
	public function filter($table)
	{
		foreach($table->getRows() as $key => $row)
		{
			//instead search must handle
			// - negative search with -piwik
			// - exact match with ""
			// see (?!pattern) 	A subexpression that performs a negative lookahead search, which matches the search string at any point where a string not matching pattern begins. 
			if( !self::match($this->patternToSearch, $this->patternToSearchQuoted, $row->getColumn($this->columnToFilter), $this->invertedMatch))
			{
				$table->deleteRow($key);
			}
		}
	}
}
