<?php
/**********************************************************************
	Copyright (C) FrontAccounting, LLC.
	Released under the terms of the GNU General Public License,
	GPL, as published by the Free Software Foundation, either version 
	3 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 License here <http://www.gnu.org/licenses/gpl-3.0.html>.
***********************************************************************/

/**
 * @return Returns the array sorted as required
 * @param $aryData Array containing data to sort
 * @param $strIndex name of column to use as an index
 * @param $strSortBy Column to sort the array by
 * @param $strSortType String containing either asc or desc [default to asc]
 * @desc Naturally sorts an array using by the column $strSortBy
 */
define('EXPORT_MAX_INSERT', 50000);

function array_natsort($aryData, $strIndex, $strSortBy, $strSortType=false) {
	// if the parameters are invalid
	if (!is_array($aryData) || !$strSortBy)
		// return the array
		return $aryData;
	// create our temporary arrays
	$arySort = $aryResult = array();

	// loop through the array
	foreach ($aryData as $key => $aryRow)
		// set up the value in the array
		$arySort[$strIndex ? $aryRow[$strIndex] : $key] = $aryRow[$strSortBy];

	// apply the natural sort
	natsort($arySort);
	// if the sort type is descending
	if ($strSortType=='desc')
		// reverse the array
		arsort($arySort);

		// loop through the sorted and original data
		foreach ($arySort as $arySortKey => $arySorted)
			if($strIndex) {
				foreach ($aryData as $aryOriginal)
					// if the key matches
					if ($aryOriginal[$strIndex]==$arySortKey)
						// add it to the output array
						array_push($aryResult, $aryOriginal);
			}
			else
				$aryResult[$arySortKey] = $aryData[$arySortKey];
	// return the return
	return $aryResult;
}

function update_admin_password($conn, $password) {
	$sql = "UPDATE ".$conn['tbpref']."users SET password=".db_escape($password) . "
		WHERE user_id='admin'";
	db_query($sql, "could not update user password for 'admin'");
}

function write_config_db($new = false) {
	global $path_to_root, $def_coy, $db_connections, $tb_pref_counter;

	if ($new)
		$tb_pref_counter++;
	$msg = "<?php\n\n";
	$msg .= "/*Connection Information for the database\n";
	$msg .= "\$def_coy - the default company that is pre-selected on login\n\n";
	$msg .= "'host' - the computer ip address or name where the database is. The default is 'localhost' assuming that the web server is also the sql server.\n\n";
	$msg .= "'port' - the computer port where the database is. The default is '3306'. Set empty for default.\n\n";
	$msg .= "'dbuser' - the user name under which the company database should be accessed.\n";
	$msg .= "  NB it is not secure to use root as the dbuser with no password - a user with appropriate privileges must be set up.\n\n";
	$msg .= "'dbpassword' - the password required for the dbuser to authorise the above database user.\n\n";
	$msg .= "'dbname' - the name of the database as defined in the RDMS being used. Typically RDMS allow many databases to be maintained under the same server.\n";
	$msg .= "'collation' - the character set used for the database.\n";
	$msg .= "'tbpref' - prefix on table names, or '' if not used. Always use non-empty prefixes if multiply company use the same database.\n";
	$msg .= "*/\n\n\n";

	$msg .= "\$def_coy = " . $def_coy . ";\n\n";
	$msg .= "\$tb_pref_counter = " . $tb_pref_counter . ";\n\n";
	$msg .= "\$db_connections = " .var_export($db_connections, true);
	$msg .= ";\n";

	$filename = $path_to_root.'/config_db.php';
	// Check if the file exists and is writable first.
	if ((!file_exists($filename) && is_writable($path_to_root)) || is_writable($filename)) {
		if (!$zp = fopen($filename, 'w'))
			return -1;
		else {
			if (!fwrite($zp, $msg)) {
				fclose($zp);
				return -2;
			}
			// Close file
			fclose($zp);
			cache_invalidate($filename);
		}
	}
	else
		return -3;

	return 0;
}

function write_extensions($extensions=null, $company = -1) {
	global $path_to_root, $installed_extensions, $next_extension_id;

	if (!isset($extensions))
		$extensions = $installed_extensions;
	if (!isset($next_extension_id))
		$next_extension_id = 1;

	$msg = "<?php\n\n";
	if ($company == -1)
		$msg .= "/* List of installed additional extensions. If extensions are added to the list manually make sure they have unique and so far never used extension_ids as a keys, and \$next_extension_id is also updated. More about format of this file yo will find in FA extension system documentation.*/\n\$next_extension_id = $next_extension_id; // unique id for next installed extension\n\n";
	else 
		$msg .= "/*Do not edit this file manually. This copy of global file is overwritten by extensions editor.*/\n\n";

	$msg .= "\$installed_extensions = ". var_export($extensions, true);
	$msg .= ";\n";
	$filename = $path_to_root . ($company==-1 ? '' : '/company/'.$company).'/installed_extensions.php';

	// Check if the file is writable first.
	if (!$zp = @fopen($filename, 'w')) {
		display_error(sprintf(_("Cannot open the extension setup file '%s' for writing."), $filename));
		return false;
	}
	else {
		if (!fwrite($zp, $msg)) {
			display_error(sprintf(_("Cannot write to the extensions setup file '%s'."), $filename));
			fclose($zp);
			return false;
		}
		// Close file
		fclose($zp);
		cache_invalidate($filename);
	}
	return true;
}
//---------------------------------------------------------------------------------------------
//
// Update per-company list of installed extensions
//
function update_extensions($extensions) {
	global $db_connections;
	
	if (!write_extensions($extensions)) {
		display_notification(_('Cannot update system extensions list.'));
		return false;
	}

	// update per company files
	$cnt = max(1, count_array($db_connections));
	for($i = 0; $i < $cnt; $i++) {
		$newexts = $extensions;
		// update 'active' status 
		$exts = get_company_extensions($i);
		foreach ($exts as $key => $ext) {
			if (isset($newexts[$key]))
				$newexts[$key]['active'] = $exts[$key]['active'];
		}
		if(!write_extensions($newexts, $i)) {
			display_notification(sprintf(_("Cannot update extensions list for company '%s'."),
				$db_connections[$i]['name']));
		 return false;
		}
	}
	return true;
}


function write_lang() {
	global $path_to_root, $installed_languages, $dflt_lang;

	$installed_languages = array_natsort($installed_languages, 'code', 'code');
	$msg = "<?php\n\n";

	$msg .= "/* How to make new entries here for non-packaged languages:\n\n";
	$msg .= "-- 'code' should match the name of the directory for the language under \\lang\n.";
	$msg .= "-- 'name' is the name that will be displayed in the language selection list (in Users and Display Setup)\n";
	$msg .= "-- 'rtl' only needs to be set for right-to-left languages like Arabic and Hebrew\n";
	$msg .= "-- 'encoding' used in translation file\n";
	$msg .= "-- 'version' always set to '' for manually installed languages.\n";
	$msg .= "-- 'path' installation path related to FA root (e.g. 'lang/en_US').\n";
	$msg .= "*/\n\n\n";

	$msg .= "\$installed_languages = " . var_export($installed_languages, true);
	$msg .= ";\n";
	$msg .= "\n\$dflt_lang = '$dflt_lang';\n";

	$path = $path_to_root."/lang";
	$filename = $path.'/installed_languages.inc';
	// Check if directory exists and is writable first.
	if (file_exists($path) && is_writable($path)) {
		if (!$zp = fopen($filename, 'w')) {
			display_error(_('Cannot open the languages file - ').$filename);
			return false;
		}
		else {
			if (!fwrite($zp, $msg)) {
				display_error(_('Cannot write to the language file - ').$filename);
				fclose($zp);
				return false;
			}
			// Close file
			fclose($zp);
			cache_invalidate($filename);
		}
	}
	else {
		display_error(_('The language files folder ').$path._(' is not writable. Change its permissions so it is, then re-run the operation.'));
		return false;
	}
	return true;
}
/*
	Database import:
		$filename - sql file name
		$connection - database connection
		$force - ignore duplicate errors
		$init - presume $filename is initialization file with '0_' prefix
		$protect - protect users/roles 
		$return_errors - return errors instead of display them
*/
function db_import($filename, $connection, $force=true, $init=true, $protect=false, $return_errors=false) {
	global $db, $SysPrefs;

	$trail = $SysPrefs->sql_trail;
	$SysPrefs->sql_trail = false;

	$allowed_commands = array(
		'create'  => 'table_queries', 
		'delimiter' => 'table_queries',
		'alter table' => 'table_queries', 
		'insert' => 'data_queries', 
		'update' => 'data_queries', 
		'set names' => 'set_names',
		'drop table if exists' => 'drop_queries',
		'drop function if exists' => 'drop_queries',
		'drop trigger if exists' => 'drop_queries',
		'select' => 'data_queries', 
		'delete' => 'data_queries',
		'drop view if exists' => 'drop_queries',
		'create view as' => 'data_queries'		//we should be able to create views after all tables have been created 
		);

	$protected = array(
		'security_roles',
		'users'
	);

	$ignored_mysql_errors = array( //errors ignored in normal (non forced) mode
		'1022',	// duplicate key
		'1050', // Table %s already exists
		'1060', // duplicate column name
		'1061', // duplicate key name
		'1062', // duplicate key entry
		'1091'  // can't drop key/column check if exists
	);

	$set_names = array();
	$data_queries = array();
	$drop_queries = array();
	$table_queries = array();
	$sql_errors = array();

	$old_encoding = db_get_charset($db);

	ini_set('max_execution_time', max('180', ini_get('max_execution_time')));
	db_query('SET foreign_key_checks=0');
	db_query("SET sql_mode=''");

	if (isset($connection['collation']))
		db_set_collation($db, $connection['collation']);

	$check_line_len = false;

	// uncompress gziped backup files
	if (strpos($filename, '.gz') || strpos($filename, '.GZ')) {
		$lines = db_ungzip('lines', $filename);
		$check_line_len = true;
	}
	elseif (strpos($filename, '.zip') || strpos($filename, '.ZIP'))
		$lines = db_unzip('lines', $filename);
	else
		$lines = file(''. $filename);

	// parse input file
	$query_table = '';
	$delimiter = ';';

	foreach($lines as $line_no => $line) {
		$gzfile_bug = $check_line_len && (strlen($line) == 8190); // there is a bug in php (at least 4.1.1-5.5.9) gzfile which limits line length to 8190 bytes!

		$line = trim($line);
		if ($init)
			$line = str_replace('0_', $connection['tbpref'], $line);

		if ($query_table == '') {	// check if line begins with one of allowed queries
			foreach($allowed_commands as $cmd => $table) {
				if (strtolower(substr($line, 0, strlen($cmd))) == $cmd) {
					if ($cmd == 'delimiter') {
						$delimiter = trim(substr($line, 10));
						continue 2;
					}
					$query_table = $table;
					$skip = false;
					if ($protect) {
						foreach($protected as $protbl)
							if (strpos($line, $connection['tbpref'].$protbl) !== false) {
								$skip = true;
								break;
							}
					}
					if (!$skip)
						${$query_table}[] = array('', $line_no+1);
					break;
				}
			}
		}
		if($query_table != '') {// inside allowed query
			$table = $query_table;
			if (!$gzfile_bug && substr($line, -strlen($delimiter)) == $delimiter) {// end of query found 
				$line = substr($line, 0, strlen($line) - strlen($delimiter)); // strip delimiter
				$query_table = '';
			}
			if (!$skip)
				${$table}[count(${$table}) - 1][0] .= $line . "\n";
		}
	}
	
	$encoding = $old_encoding; // UI encoding for default site language is the default
	$new_file = count($set_names);
	
	if ($new_file) {
		if (count($set_names)) {// standard db restore
			if (preg_match('/set\s*names\s*[\']?(\w*)[\']?/i', $set_names[0][0], $match))
				$encoding = $match[1];
		}
		// otherwise use default site ui encoding
	}

	db_set_charset($db, $encoding);

/*/	{ 	// for debugging purposes
	global $path_to_root;
	$f = fopen($path_to_root.'/tmp/dbimport.txt', 'w+');
	fwrite($f, print_r($set_names,true) ."\n");
	fwrite($f, print_r($drop_queries,true) ."\n");
	fwrite($f, print_r($table_queries,true) ."\n");
	fwrite($f, print_r($data_queries,true));
	fclose($f);
	}
/*/
	if ($return_errors) {	// prevent errors display
		$save_debug = $SysPrefs->go_debug;
		$SysPrefs->go_debug = 0;
	}
	// execute drop tables if exists queries
	if (is_array($drop_queries)) {
		foreach($drop_queries as $drop_query) {
			if (!db_query($drop_query[0])) {
				if (!in_array(db_error_no(), $ignored_mysql_errors) || !$force)
					$sql_errors[] = array(db_error_msg($db), $drop_query[1]);
			}
		}
	}

	// execute create tables queries
	if (is_array($table_queries)) {
		foreach($table_queries as $table_query) {
			if (!db_query($table_query[0])) {	
				if (!in_array(db_error_no(), $ignored_mysql_errors) || !$force)
					$sql_errors[] = array(db_error_msg($db), $table_query[1]);
			}
		}
	}

	// execute insert data queries
	if (is_array($data_queries)) {
		foreach($data_queries as $data_query) {
			if (!db_query($data_query[0])) {
				if (!in_array(db_error_no(),$ignored_mysql_errors) || !$force)
					$sql_errors[] = array(db_error_msg($db), $data_query[1]);
			}
		}
	}

	if ($return_errors)
		$SysPrefs->go_debug = $save_debug;

	$SysPrefs->sql_trail = $trail;

	db_query("SET foreign_key_checks=1");
	if ($delimiter != ';') db_query("delimiter ;"); // just for any case

	db_set_charset($db, $old_encoding); // restore connection encoding

	if (count($sql_errors)) {
		if ($return_errors)
			return $sql_errors;

		// display first failure message; the rest are probably derivative 
		$err = $sql_errors[0];
		display_error(sprintf(_('SQL script execution failed in line %d: %s'),
			$err[1], $err[0]));
		return false;
	}
	else
		return true;
}

// returns the content of the gziped $path backup file. use of $mode see below
function db_ungzip($mode, $path) {
	$file_data = gzfile($path);
	// returns one string or an array of lines
	if ($mode != 'lines')
		return implode('', $file_data);
	else
		return $file_data;
}

// returns the content of the ziped $path backup file. use of $mode see below
function db_unzip($mode, $path) {
	$all = false;
	$all = implode('', file($path));

	// convert path to name of ziped file
	$filename = preg_replace("/.*\//", "", $path);
	$filename = substr($filename, 0, strlen($filename) - 4);

	// compare filname in zip and filename from $_GET
	if (substr($all, 30, strlen($filename)-4) . substr($all, 30+strlen($filename)+9, 4) != $filename)
		return '';     // exit if names differ
	else {
		// get the suffix of the filename in hex
		$crc_bugfix = substr($all, 30, strlen($filename)+13);
		$crc_bugfix = substr(substr($crc_bugfix, 0, strlen($crc_bugfix) - 4), 
				strlen($crc_bugfix) - 12 - 4);
		$suffix = false;
		// convert hex to ascii
		for ($i=0; $i < 12; )
			$suffix .= chr($crc_bugfix[$i++] . $crc_bugfix[$i++] . $crc_bugfix[$i++]);

		// remove central directory information (we have always just one ziped file)
		$comp = substr($all, -(strlen($all) - 30 - strlen($filename)-13));
		$comp = substr($comp, 0, (strlen($comp) - 80 - strlen($filename)-13));

		// fix the crc bugfix (see function save_to_file)
		$comp = "xœ" . $comp . $suffix;
		$file_data = gzuncompress($comp);
	}

	// returns one string or an array of lines
	if ($mode != 'lines')
		return $file_data;
	else
		return explode("\n", $file_data);
}

function db_backup($conn, $ext='no', $comm='', $path='') {
	if ($conn['tbpref'] != '')
		$filename = $conn['dbname'].'_'.$conn['tbpref'].date('Ymd_Hi').'.sql';
	else
		$filename = $conn['dbname'].'_'.date('Ymd_Hi').'.sql';

	return db_export($conn, $path.clean_file_name($filename), $ext, $comm);
}
// Generates a dump of $db database
//
function db_export($conn, $filename, $zip='no', $comment='') {

	global $SysPrefs, $version;

	$error = false;
	// set max string size before writing to file
	$max_size = 1048576 * 2; // 2 MB
	// changes max size if value can be retrieved
	if (ini_get('memory_limit'))
		$max_size = 1048576 * (int)ini_get('memory_limit');
	// set backupfile name
	if ($zip == 'gzip')
		$backupfile = $filename.'.gz';
	elseif ($zip == 'zip')
		$backupfile = $filename.'.zip';
	else
		$backupfile = $filename;
	$company = $conn['name']; // get_company_pref('coy_name');

	if (file_exists($backupfile))	// prevent appends
		unlink($backupfile);

	//create comment
	$out="# MySQL dump of database '".$conn["dbname"]."' on host '".$conn["host"]."'\n";
	$out.="# Backup Date and Time: ".date("Y-m-d H:i")."\n";
	$out.="# Built by " . $SysPrefs->app_title . " " . $version ."\n";
	$out.="# ".$SysPrefs->power_url."\n";
	$out.="# Company: ". @html_entity_decode($company, ENT_QUOTES, $_SESSION['language']->encoding)."\n";
	$out.="# User: ".$_SESSION['wa_current_user']->name."\n\n";
	$out.="# Compatibility: ".get_company_pref('version_id')."\n\n";

	// write users comment
	if ($comment) {
		$out .= "# Comment:\n";
		$comment=preg_replace("'\n'","\n# ","# ".$comment);
		//$comment=str_replace("\n", "\n# ", $comment);
		foreach(explode("\n",$comment) as $line)
			$out .= $line."\n";
		$out.="\n";
	}

	db_set_encoding();
	if ($mysql_enc = get_mysql_encoding_name($_SESSION['language']->encoding))
		$out .= "\nSET NAMES $mysql_enc;\n";
	
	// get auto_increment values and names of all tables
	$res = db_query('show table status');
	$all_tables = array();
	while($row = db_fetch($res)) {
		if (($conn['tbpref'] == '' && !preg_match('/[0-9]+_/', $row['Name'])) ||
			($conn['tbpref'] != '' && strpos($row['Name'], $conn['tbpref']) === 0))
			$all_tables[] = $row;
	}
		// get table structures
	foreach ($all_tables as $table) {
		$res1 = db_query("SHOW CREATE TABLE `" . $table['Name'] . "`");
		$tmp = db_fetch($res1);
		$table_sql[$table['Name']] = $tmp['Create Table'];
	}

	// find foreign keys
	$fks = array();
	if (isset($table_sql)) {
		foreach($table_sql as $tablenme=>$table) {
			$tmp_table=$table;
			// save all tables, needed for creating this table in $fks
			while (($ref_pos = strpos($tmp_table, " REFERENCES ")) > 0) {
				$tmp_table = substr($tmp_table, $ref_pos + 12);
				$ref_pos = strpos($tmp_table, "(");
				$fks[$tablenme][] = substr($tmp_table, 0, $ref_pos);
			}
		}
	}
	// order $all_tables
	$all_tables = order_sql_tables($all_tables, $fks);

	// as long as no error occurred
	if (!$error) {
		foreach ($all_tables as $row) {
			if (!empty($row['Engine'])) {	//don't export views like tables
				$tablename = $row['Name'];
				$auto_incr[$tablename] = $row['Auto_increment'];
				$out.="\n\n";
				// export tables
				$out.="### Structure of table `".$tablename."` ###\n\n";
				$out.="DROP TABLE IF EXISTS `".$tablename."`;\n\n";
				$out.=$table_sql[$tablename];
				$out.=" ;";
				$out.="\n\n";
	
				// export data
				if (!$error) {
					$out.="### Data of table `".$tablename."` ###\n";
	
					// check if field types are NULL or NOT NULL
					$res3 = db_query("SHOW COLUMNS FROM `" . $tablename . "`");
	
					$field_null = array();
					for ($j = 0; $j < db_num_rows($res3); $j++) {
						$row3 = db_fetch($res3);
						$field_null[] = $row3[2]=='YES' && $row3[4]===null;
					}
	
					$res2 = db_query("SELECT * FROM `" . $tablename . "`");
					$maxinsert = 0;
					$insert = '';
					for ($j = 0; $j < db_num_rows($res2); $j++) {
						$row2 = db_fetch_row($res2);
						$values = '(';
						for ($k = 0; $k < $nf = db_num_fields($res2); $k++) {
							$values .= db_escape($row2[$k], $field_null[$k]);
							if ($k < ($nf - 1))
								$values .= ', ';
						}
						$values .= ')';
						$len = strlen($values);
						if ($maxinsert < $len+1) {
							$maxinsert = EXPORT_MAX_INSERT;
							if ($insert) {
								$out .= $insert .';'; // flush insert query
								$insert = '';
							}
						}
	
						if ($insert == '') {
							$insert = "\nINSERT INTO `" . $tablename . "` VALUES\n";
							$maxinsert -= strlen($insert);
						}
						else
							$insert .= ",\n";
	
						$maxinsert -= $len;
						$insert .= $values;
	
						// if saving is successful, then empty $out, else set error flag
						if (strlen($out) > $max_size && $zip != "zip") {
							if (save_to_file($backupfile, $zip, $out))
								$out = "";
							else
								$error = true;
						}
					}
					if ($insert)
						$out .= $insert. ';';
				// an error occurred! Try to delete file and return error status
				}
				elseif ($error) {
					@unlink($backupfile);
					return false;
				}
	
				// if saving is successful, then empty $out, else set error flag
				if (strlen($out) > $max_size && $zip != 'zip') {
					if (save_to_file($backupfile, $zip, $out))
						$out= '';
					else
						$error = true;
				}
			}	//end if Engine set (not a view)
		}
		//process views last so all tables have been created before views are created
		foreach ($all_tables as $row) {
			if (empty($row['Engine'])) {
				$viewname = $row['Name'];
				$out .= "\n\nDROP VIEW IF EXISTS `".$viewname."`;\n";
				//db_get_view_schema() is in /includes/db/connect_db_mysqli.inc because it is mysql specific
				if (NULL !== ($schema = db_get_view_schema($viewname))) {
					$out .= "CREATE VIEW `".$viewname."` AS ".$schema.";\n\n";
					if (!save_to_file($backupfile, $zip, $out)) $error = true;
					else $out = '';
				}
				else $error = true;
				
				if ($error) {
					@unlink($backupfile);
					return false;
				}
			}
		}

	// an error occurred! Try to delete file and return error status
	}
	else {
		@unlink($backupfile);
		return false;
	}

	if (save_to_file($backupfile, $zip, $out))
		$out = '';
	else {
		@unlink($backupfile);
		return false;
	}
	return $backupfile;
}

// orders the tables in $tables according to the constraints in $fks
// $fks musst be filled like this: $fks[tablename][0]=needed_table1; $fks[tablename][1]=needed_table2; ...
function order_sql_tables($tables, $fks) {
	// do not order if no contraints exist
	if (!count($fks))
		return $tables;

	// order
	$new_tables = array();
	$existing = array();
	$modified = true;
	while (count($tables) && $modified == true) {
		$modified = false;
		foreach ($tables as $key=>$row) {
			// delete from $tables and add to $new_tables
			if (isset($fks[$row['Name']])) {
				foreach($fks[$row['Name']] as $needed) {
					// go to next table if not all needed tables exist in $existing
					if (!in_array($needed,$existing))
						continue 2;
				}
			}
			// delete from $tables and add to $new_tables
			$existing[] = $row['Name'];
			$new_tables[] = $row;
			prev($tables);
			unset($tables[$key]);
			$modified = true;
		}
	}

	if (count($tables)) {
		// probably there are 'circles' in the constraints, bacause of that no proper backups can be created yet
		// TODO: this will be fixed sometime later through using 'alter table' commands to add the constraints after generating the tables
		// until now, just add the lasting tables to $new_tables, return them and print a warning
		foreach($tables as $row)
			$new_tables[] = $row;
		echo "<div class=\"red_left\">THIS DATABASE SEEMS TO CONTAIN 'RING CONSTRAINTS'. WA DOES NOT SUPPORT THEM. PROBABLY THE FOLOWING BACKUP IS DEFECT!</div>";
	}
	return $new_tables;
}

// saves the string in $fileData to the file $backupfile as gz file or not ($zip)
// returns backup file name if name has changed (zip), else TRUE. If saving failed, return value is FALSE
function save_to_file($path, $zip, $fileData) {

	$backupfile = basename($path);

	if ($zip == 'gzip') {
		if ($zp = @gzopen($path, 'a9')) {
			@gzwrite($zp, $fileData);
			@gzclose($zp);
			return true;
		}
		else
			return false;

	// $zip contains the timestamp
	}
	elseif ($zip == 'zip') {
		// based on zip.lib.php 2.2 from phpMyBackupAdmin
		// offical zip format: http://www.pkware.com/appnote.txt

		// End of central directory record
		$eof_ctrl_dir = "\x50\x4b\x05\x06\x00\x00\x00\x00";

		// "local file header" segment
		$unc_len = strlen($fileData);
		$crc = crc32($fileData);
		$zdata = gzcompress($fileData);

		// extend stored file name with suffix
		// needed for decoding (because of crc bug)
		$name_suffix = substr($zdata, -4, 4);
		$name_suffix2 = '_';
		for ($i = 0; $i < 4; $i++)
			$name_suffix2 .= sprintf("%03d", ord($name_suffix[$i]));

		$name = substr($backupfile, 0, strlen($backupfile) - 8) . $name_suffix2 . ".sql";

		// fix crc bug
		$zdata = substr(substr($zdata, 0, strlen($zdata) - 4), 2);
		$c_len = strlen($zdata);

		// dos time
		$timearray = getdate();
		$dostime = (($timearray['year'] - 1980) << 25) | ($timearray['mon'] << 21) | ($timearray['mday'] << 16) | ($timearray['hours'] << 11) | ($timearray['minutes'] << 5) | ($timearray['seconds'] >> 1);
		$dtime = dechex($dostime);
		$hexdtime = "\x" . $dtime[6] . $dtime[7] . "\x" . $dtime[4].$dtime[5] . "\x" . $dtime[2] . $dtime[3] . "\x" . $dtime[0] . $dtime[1];
		eval('$hexdtime="' . $hexdtime . '";');

		// ver needed to extract, gen purpose bit flag, compression method, last mod time and date
		$sub1 = "\x14\x00" . "\x00\x00" . "\x08\x00" . $hexdtime;

		// crc32, compressed filesize, uncompressed filesize
		$sub2 = pack('V', $crc) . pack('V', $c_len) . pack('V', $unc_len);

		$fr = "\x50\x4b\x03\x04" . $sub1. $sub2;

		// length of filename, extra field length
		$fr .= pack('v', strlen($name)) . pack('v', 0);
		$fr .= $name;

		// "file data" segment and "data descriptor" segment (optional but necessary if archive is not served as file)
		$fr .= $zdata . $sub2;

		// now add to central directory record
		$cdrec = "\x50\x4b\x01\x02";
		$cdrec .= "\x00\x00";                // version made by
		$cdrec .= $sub1 . $sub2;

		 // length of filename, extra field length, file comment length, disk number start, internal file attributes, external file attributes - 'archive' bit set, offset
		$cdrec .= pack('v', strlen($name)) . pack('v', 0) . pack('v', 0) . pack('v', 0) . pack('v', 0) . pack('V', 32) . pack('V',0);
		$cdrec .= $name;

		// combine data
		$fileData = $fr . $cdrec . $eof_ctrl_dir;

		// total # of entries "on this disk", total # of entries overall, size of central dir, offset to start of central dir, .zip file comment length
		$fileData .= pack('v', 1) . pack('v', 1) . pack('V', strlen($cdrec)) . pack('V', strlen($fr)) . "\x00\x00";

		if ($zp = @fopen($path, 'w')) {
			@fwrite($zp, $fileData);
			@fclose($zp);
			return true;
		}
		else
			return false;

	// uncompressed
	}
	else {
		if ($zp = @fopen($path, 'a')) {
			@fwrite($zp, $fileData);
			@fclose($zp);
			return true;
		}
		else {
			return false;
		}
	}
}

function create_comp_dirs($comp_path, $comp_subdirs) {
	$index = "<?php\nheader(\"Location: ../index.php\");\n";
	$cdir = $comp_path;
	@mkdir($cdir);
	$f = @fopen("$cdir/index.php", 'wb');
	@fwrite($f, $index);
	@fclose($f);

	foreach($comp_subdirs as $dir) {
		@mkdir($cdir.'/'.$dir);
		$f = @fopen("$cdir/$dir/index.php", 'wb');
		@fwrite($f, $index);
		@fclose($f);
	}
}

//
//	Checks $field existence in $table with given field $properties
//	$table - table name without prefix
//  $field -  optional field name
//  $properties - optional properties of field defined by MySQL:
//		'Type', 'Null', 'Key', 'Default', 'Extra'
//
function check_table($pref, $table, $field=null, $properties=null) {
	$tables = @db_query("SHOW TABLES LIKE '".$pref.$table."'");
	if (!db_num_rows($tables))
		return 1;		// no such table or error

	$fields = @db_query("SHOW COLUMNS FROM ".$pref.$table);
	if (!isset($field)) 
		return 0;		// table exists

	while( $row = db_fetch_assoc($fields)) {
		if ($row['Field'] == $field) {
			if (!isset($properties)) 
				return 0;
			foreach($properties as $property => $value) {
				if ($row[$property] != $value) 
					return 3;	// failed type/length check
			}
			return 0; // property check ok.
		}
	}
	return 2; // field not found
}

/*
	Update or create setting in simple php config file.
*/
function update_config_var($file, $variable, $value, $comment='') {
	if (!is_file($file) || !is_writeable($file))
		return false;
	$content = file_get_contents($file);
	$strvalue = '$'."$variable = ".var_export($value, true).';';
	$pattern = '/'.preg_quote('$'.$variable).'\s*=\s*[^;]*;/m';
	$content = preg_replace($pattern, $strvalue, $content, -1, $result);
	if (!$result) {
		$strvalue = ($comment ? "// $comment" : '') ."\n$strvalue\n";
		$content = preg_replace('/\?>\s*/m', $strvalue, $content, -1, $result);
		if (!$result)
			$content .= $strvalue;
	}

	return file_put_contents($file, $content)!=false;
}