<?php
/***************************************************************************
*                              functions_search.php
*                              -------------------
*     begin                : Wed Sep 05 2001
*     copyright            : (C) 2001 The phpBB Group
*     email                : support@phpbb.com
*
*     $Id$
*
****************************************************************************/

/***************************************************************************
 *
 *   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.
 *
 ***************************************************************************/

function clean_words($mode, &$entry, &$stopword_list, &$synonym_list)
{
	// Weird, $init_match doesn't work with static when double quotes (") are used...
	static $drop_char_match =   array('^', '$', '&', '(', ')', '<', '>', '`', '\'', '"', '|', ',', '@', '_', '?', '%', '-', '~', '+', '.', '[', ']', '{', '}', ':', '\\', '/', '=', '#', '\'', ';', '!');
	static $drop_char_replace = array(' ', ' ', ' ', ' ', ' ', ' ', ' ', '',  '',   ' ', ' ', ' ', ' ', '',  ' ', ' ', '',  ' ',   ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ' , ' ', ' ', ' ', ' ',  ' ', ' ');

	$entry = ' ' . strip_tags(strtolower($entry)) . ' ';

	if ( $mode == 'post' )
	{
		// Replace line endings by a space
		$entry = preg_replace('/[\n\r]/is', ' ', $entry); 
		// HTML entities like &nbsp;
		$entry = preg_replace('/\b&[a-z]+;\b/', ' ', $entry); 
		// Remove URL's
		$entry = preg_replace('/\b[a-z0-9]+:\/\/[a-z0-9\.\-]+(\/[a-z0-9\?\.%_\-\+=&\/]+)?/', ' ', $entry); 
		// Quickly remove BBcode.
		$entry = preg_replace('/\[img:[a-z0-9]{10,}\].*?\[\/img:[a-z0-9]{10,}\]/', ' ', $entry); 
		$entry = preg_replace('/\[\/?url(=.*?)?\]/', ' ', $entry);
		$entry = preg_replace('/\[\/?[a-z\*=\+\-]+(\:?[0-9a-z]+)?:[a-z0-9]{10,}(\:[a-z0-9]+)?=?.*?\]/', ' ', $entry);
	}
	else if ( $mode == 'search' ) 
	{
		$entry = str_replace('+', ' and ', $entry);
		$entry = str_replace('-', ' not ', $entry);
	}

	// Replace numbers on their own
	$entry = preg_replace('/\b[0-9]+\b/', ' ', $entry); 

	//
	// Filter out strange characters like ^, $, &, change "it's" to "its"
	//
	for($i = 0; $i < count($drop_char_match); $i++)
	{
		$entry =  str_replace($drop_char_match[$i], $drop_char_replace[$i], $entry);
	}

	if ( $mode == 'post' )
	{
		$entry = str_replace('*', ' ', $entry);

		// 'words' that consist of <=3 or >=25 characters are removed.
		$entry = preg_replace('/\b([a-z0-9]{1,3}|[a-z0-9]{20,})\b/',' ', $entry); 
	}

	if ( !empty($stopword_list) )
	{
		for ($j = 0; $j < count($stopword_list); $j++)
		{
			$stopword = trim($stopword_list[$j]);

			if ( $mode == 'post' || ( $stopword != 'not' && $stopword != 'and' && $stopword != 'or' ) )
			{
				$entry =  preg_replace('#\b' . preg_quote($stopword) . '\b#', ' ', $entry);
			}
		}
	}

	if ( !empty($synonym_list) )
	{
		for ($j = 0; $j < count($synonym_list); $j++)
		{
			list($replace_synonym, $match_synonym) = split(' ', trim(strtolower($synonym_list[$j])));
			if ( $mode == 'post' || ( $match_synonym != 'not' && $match_synonym != 'and' && $match_synonym != 'or' ) )
			{
				$entry =  preg_replace('#\b' . trim($match_synonym) . '\b#', ' ' . trim($replace_synonym) . ' ', $entry);
			}
		}
	}

	return $entry;
}

function split_words(&$entry, $mode = 'post')
{
	if ( $mode == 'post' )
	{
		preg_match_all("/\b(\w[\w']*\w+|\w+?)\b/", $entry, $split_entries);
	}
	else
	{
		preg_match_all('/(\*?[a-z0-9]+\*?)|\b([a-z0-9]+)\b/', $entry, $split_entries);
	}

	return $split_entries[1];
}

function add_search_words($post_id, $post_text, $post_title = '')
{
	global $db, $phpbb_root_path, $board_config, $lang;

	$stopwords_array = @file($phpbb_root_path . 'language/lang_' . $board_config['default_lang'] . "/search_stopwords.txt"); 
	$synonym_array = @file($phpbb_root_path . 'language/lang_' . $board_config['default_lang'] . "/search_synonyms.txt"); 

	$search_raw_words = array();
	$search_raw_words['text'] = split_words(clean_words('post', $post_text, $stopword_array, $synonym_array));
	$search_raw_words['title'] = split_words(clean_words('post', $post_title, $stopword_array, $synonym_array));

	$word = array();
	$word_insert_sql = array();
	while ( list($word_in, $search_matches) = @each($search_raw_words) )
	{
		$word_insert_sql[$word_in] = '';
		if ( !empty($search_matches) )
		{
			for ($i = 0; $i < count($search_matches); $i++)
			{ 
				$search_matches[$i] = trim($search_matches[$i]);

				if( $search_matches[$i] != '' ) 
				{
					$word[] = $search_matches[$i];
					if ( !strstr($word_insert_sql[$word_in], "'" . $search_matches[$i] . "'") )
					{
						$word_insert_sql[$word_in] .= ( $word_insert_sql[$word_in] != "" ) ? ", '" . $search_matches[$i] . "'" : "'" . $search_matches[$i] . "'";
					}
				} 
			}
		}
	}

	if ( count($word) )
	{
		sort($word);

		$prev_word = '';
		$word_text_sql = '';
		$temp_word = array();
		for($i = 0; $i < count($word); $i++)
		{
			if ( $word[$i] != $prev_word )
			{
				$temp_word[] = $word[$i];
				$word_text_sql .= ( ( $word_text_sql != '' ) ? ', ' : '' ) . "'" . $word[$i] . "'";
			}
			$prev_word = $word[$i];
		}
		$word = $temp_word;

		$check_words = array();
		switch( SQL_LAYER )
		{
			case 'postgresql':
			case 'msaccess':
			case 'mssql-odbc':
			case 'oracle':
			case 'db2':
				$sql = "SELECT word_id, word_text     
					FROM " . SEARCH_WORD_TABLE . " 
					WHERE word_text IN ($word_text_sql)";
				if ( !($result = $db->sql_query($sql)) )
				{
					message_die(GENERAL_ERROR, 'Could not select words', '', __LINE__, __FILE__, $sql);
				}

				while ( $row = $db->sql_fetchrow($result) )
				{
					$check_words[$row['word_text']] = $row['word_id'];
				}
				break;
		}

		$value_sql = '';
		$match_word = array();
		for ($i = 0; $i < count($word); $i++)
		{ 
			$new_match = true;
			if ( isset($check_words[$word[$i]]) )
			{
				$new_match = false;
			}

			if ( $new_match )
			{
				switch( SQL_LAYER )
				{
					case 'mysql':
					case 'mysql4':
						$value_sql .= ( ( $value_sql != '' ) ? ', ' : '' ) . '(\'' . $word[$i] . '\')';
						break;
					case 'mssql':
						$value_sql .= ( ( $value_sql != '' ) ? ' UNION ALL ' : '' ) . "SELECT '" . $word[$i] . "'";
						break;
					default:
						$sql = "INSERT INTO " . SEARCH_WORD_TABLE . " (word_text) 
							VALUES ('" . $word[$i] . "')"; 
						if( !$db->sql_query($sql) )
						{
							message_die(GENERAL_ERROR, 'Could not insert new word', '', __LINE__, __FILE__, $sql);
						}
						break;
				}
			}
		}

		if ( $value_sql != '' )
		{
			switch ( SQL_LAYER )
			{
				case 'mysql':
				case 'mysql4':
					$sql = "INSERT IGNORE INTO " . SEARCH_WORD_TABLE . " (word_text) 
						VALUES $value_sql"; 
					break;
				case 'mssql':
					$sql = "INSERT INTO " . SEARCH_WORD_TABLE . " (word_text) 
						$value_sql"; 
					break;
			}

			if ( !$db->sql_query($sql) )
			{
				message_die(GENERAL_ERROR, 'Could not insert new word', '', __LINE__, __FILE__, $sql);
			}
		}
	}

	while( list($word_in, $match_sql) = @each($word_insert_sql) )
	{
		$title_match = ( $word_in == 'title' ) ? 1 : 0;

		if ( $match_sql != '' )
		{
			$sql = "INSERT INTO " . SEARCH_MATCH_TABLE . " (post_id, word_id, title_match) 
				SELECT $post_id, word_id, $title_match  
					FROM " . SEARCH_WORD_TABLE . " 
					WHERE word_text IN ($match_sql)"; 
			if ( !$db->sql_query($sql) )
			{
				message_die(GENERAL_ERROR, 'Could not insert new word matches', '', __LINE__, __FILE__, $sql);
			}
		}
	}

	if ( $mode == 'single' )
	{
		remove_common('single', 0.4, $word);
	}

	return;
}

//
// Check if specified words are too common now
//
function remove_common($mode, $fraction, $word_id_list = array())
{
	global $db;

	$sql = ( $mode == 'global' ) ? "SELECT COUNT(post_id) AS total_posts FROM " . SEARCH_MATCH_TABLE . " GROUP BY post_id" : "SELECT SUM(forum_posts) AS total_posts FROM " . FORUMS_TABLE;
	if ( !($result = $db->sql_query($sql)) )
	{
		message_die(GENERAL_ERROR, 'Could not obtain post count', '', __LINE__, __FILE__, $sql);
	}

	$row = $db->sql_fetchrow($result);

	if ( $row['total_posts'] >= 100 )
	{
		$common_threshold = floor($row['total_posts'] * $fraction);

		if ( $mode == 'single' && count($word_id_list) )
		{
			$word_id_sql = '';
			for($i = 0; $i < count($word_id_list); $i++)
			{
				$word_id_sql .= ( ( $word_id_sql != '' ) ? ', ' : '' ) . "'" . $word_id_list[$i] . "'";
			}

			$sql = "SELECT m.word_id 
				FROM " . SEARCH_MATCH_TABLE . " m, " . SEARCH_WORD_TABLE . " w 
				WHERE w.word_text IN ($word_id_sql)  
					AND m.word_id = w.word_id 
				GROUP BY m.word_id 
				HAVING COUNT(m.word_id) > $common_threshold";
		}
		else 
		{
			$sql = "SELECT word_id 
				FROM " . SEARCH_MATCH_TABLE . " 
				GROUP BY word_id 
				HAVING COUNT(word_id) > $common_threshold";
		}

		if ( !($result = $db->sql_query($sql)) )
		{
			message_die(GENERAL_ERROR, 'Could not obtain common word list', '', __LINE__, __FILE__, $sql);
		}

		$common_word_id = '';
		while ( $row = $db->sql_fetchrow($result) )
		{
			$common_word_id .= ( ( $common_word_id != '' ) ? ', ' : '' ) . $row['word_id'];
		}
		$db->sql_freeresult($result);

		if ( $common_word_id != '' )
		{
			$sql = "UPDATE " . SEARCH_WORD_TABLE . "
				SET word_common = " . TRUE . " 
				WHERE word_id IN ($common_word_id)";
			if ( !$db->sql_query($sql) )
			{
				message_die(GENERAL_ERROR, 'Could not delete word list entry', '', __LINE__, __FILE__, $sql);
			}

			$sql = "DELETE FROM " . SEARCH_MATCH_TABLE . "  
				WHERE word_id IN ($common_word_id)";
			if ( !$db->sql_query($sql) )
			{
				message_die(GENERAL_ERROR, 'Could not delete word match entry', '', __LINE__, __FILE__, $sql);
			}
		}
	}

	return $word_count;
}

function remove_search_post($post_id_sql)
{
	global $db;

	$words_removed = false;

	switch ( SQL_LAYER )
	{
		case 'mysql':
		case 'mysql4':
			$sql = "SELECT word_id 
				FROM " . SEARCH_MATCH_TABLE . " 
				WHERE post_id IN ($post_id_sql) 
				GROUP BY word_id";
			if ( $result = $db->sql_query($sql) )
			{
				$word_id_sql = '';
				while ( $row = $db->sql_fetchrow($result) )
				{
					$word_id_sql .= ( $word_id_sql != '' ) ? ', ' . $row['word_id'] : $row['word_id']; 
				}

				$sql = "SELECT word_id 
					FROM " . SEARCH_MATCH_TABLE . " 
					WHERE word_id IN ($word_id_sql) 
					GROUP BY word_id 
					HAVING COUNT(word_id) = 1";
				if ( $result = $db->sql_query($sql) )
				{
					$word_id_sql = '';
					while ( $row = $db->sql_fetchrow($result) )
					{
						$word_id_sql .= ( $word_id_sql != '' ) ? ', ' . $row['word_id'] : $row['word_id']; 
					}

					if ( $word_id_sql != '' )
					{
						$sql = "DELETE FROM " . SEARCH_WORD_TABLE . " 
							WHERE word_id IN ($word_id_sql)";
						if ( !$db->sql_query($sql) )
						{
							message_die(GENERAL_ERROR, 'Could not delete word list entry', '', __LINE__, __FILE__, $sql);
						}

						$words_removed = $db->sql_affectedrows();
					}
				}
			}
			break;

		default:
			$sql = "DELETE FROM " . SEARCH_WORD_TABLE . " 
				WHERE word_id IN ( 
					SELECT word_id 
					FROM " . SEARCH_MATCH_TABLE . " 
					WHERE word_id IN ( 
						SELECT word_id 
						FROM " . SEARCH_MATCH_TABLE . " 
						WHERE post_id IN ($post_id_sql) 
						GROUP BY word_id 
					) 
					GROUP BY word_id 
					HAVING COUNT(word_id) = 1
				)"; 
			if ( !$db->sql_query($sql) )
			{
				message_die(GENERAL_ERROR, 'Could not delete old words from word table', '', __LINE__, __FILE__, $sql);
			}

			$words_removed = $db->sql_affectedrows();

			break;
	}

	$sql = "DELETE FROM " . SEARCH_MATCH_TABLE . "  
		WHERE post_id IN ($post_id_sql)";
	if ( !$db->sql_query($sql) )
	{
		message_die(GENERAL_ERROR, 'Error in deleting post', '', __LINE__, __FILE__, $sql);
	}

	return $words_removed;
}

//
// Username search
//
function username_search($search_match)
{
	global $db, $board_config, $template, $lang, $images, $theme, $phpEx, $phpbb_root_path;
	global $starttime;

	$username_list = '';
	if ( !empty($search_match) )
	{
		$username_search = preg_replace('/\*/', '%', trim(strip_tags($search_match)));

		$sql = "SELECT username 
			FROM " . USERS_TABLE . " 
			WHERE username LIKE '" . str_replace("\'", "''", $username_search) . "' 
			ORDER BY username";
		if ( !($result = $db->sql_query($sql)) )
		{
			message_die(GENERAL_ERROR, 'Could not obtain search results', '', __LINE__, __FILE__, $sql);
		}

		if ( $row = $db->sql_fetchrow($result) )
		{
			do
			{
				$username_list .= '<option value="' . $row['username'] . '">' . $row['username'] . '</option>';
			}
			while ( $row = $db->sql_fetchrow($result) );
		}
		else
		{
			$username_list .= '<option>' . $lang['No_match']. '</option>';
		}
		$db->sql_freeresult($result);
	}

	$gen_simple_header = TRUE;
	$page_title = $lang['Search'];
	include($phpbb_root_path . 'includes/page_header.'.$phpEx);

	$template->set_filenames(array(
		'search_user_body' => 'search_username.tpl')
	);

	$template->assign_vars(array(
		'USERNAME' => ( !empty($search_match) ) ? $search_match : '', 

		'L_CLOSE_WINDOW' => $lang['Close_window'], 
		'L_SEARCH_USERNAME' => $lang['Find_username'], 
		'L_UPDATE_USERNAME' => $lang['Select_username'], 
		'L_SELECT' => $lang['Select'], 
		'L_SEARCH' => $lang['Search'], 
		'L_SEARCH_EXPLAIN' => $lang['Search_author_explain'], 
		'L_CLOSE_WINDOW' => $lang['Close_window'], 

		'S_USERNAME_OPTIONS' => $username_list, 
		'S_SEARCH_ACTION' => append_sid("search.$phpEx?mode=searchuser"))
	);

	if ( $username_list != '' )
	{
		$template->assign_block_vars('switch_select_name', array());
	}

	$template->pparse('search_user_body');

	include($phpbb_root_path . 'includes/page_tail.'.$phpEx);

	return;
}

?>