<?php
# Copyright (C) 2004 Brion Vibber <brion@pobox.com>
# http://www.mediawiki.org/
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
# http://www.gnu.org/copyleft/gpl.html

/**
 * Search engine hook for MySQL 4+
 * @addtogroup Search
 */
class SearchMySQL4 extends SearchMySQL {
	var $strictMatching = true;

	/** @todo document */
	function SearchMySQL4( $db ) {
		$this->db = $db;
	}

	/** @todo document */
	function parseQuery( $filteredText, $fulltext ) {
		global $wgContLang;
		$lc = SearchEngine::legalSearchChars();
		$searchon = '';
		$this->searchTerms = array();

		# FIXME: This doesn't handle parenthetical expressions.
		$m = array();
		if( preg_match_all( '/([-+<>~]?)(([' . $lc . ']+)(\*?)|"[^"]*")/',
			  $filteredText, $m, PREG_SET_ORDER ) ) {
			foreach( $m as $terms ) {
				if( $searchon !== '' ) $searchon .= ' ';
				if( $this->strictMatching && ($terms[1] == '') ) {
					$terms[1] = '+';
				}
				$searchon .= $terms[1] . $wgContLang->stripForSearch( $terms[2] );
				if( !empty( $terms[3] ) ) {
					$regexp = preg_quote( $terms[3], '/' );
					if( $terms[4] ) $regexp .= "[0-9A-Za-z_]+";
				} else {
					$regexp = preg_quote( str_replace( '"', '', $terms[2] ), '/' );
				}
				$this->searchTerms[] = $regexp;
			}
			wfDebug( "Would search with '$searchon'\n" );
			wfDebug( 'Match with /\b' . implode( '\b|\b', $this->searchTerms ) . "\b/\n" );
		} else {
			wfDebug( "Can't understand search query '{$filteredText}'\n" );
		}

		$searchon = $this->db->strencode( $searchon );
		$field = $this->getIndexField( $fulltext );
		return " MATCH($field) AGAINST('$searchon' IN BOOLEAN MODE) ";
	}
}