<?php
/*
* LE CHAT-PHP - a PHP Chat based on LE CHAT - Main program
*
* Copyright (C) 2015-2021 Daniel Winzen <daniel@danwin1210.me>
*
* 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 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
* 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, see <http://www.gnu.org/licenses/>.
*/

/*
* status codes
* 0 - Kicked/Banned
* 1 - Guest
* 2 - Applicant
* 3 - Member
* 4 - System message
* 5 - Moderator
* 6 - Super-Moderator
* 7 - Admin
* 8 - Super-Admin
* 9 - Private messages
*/

// initialize and load variables/configuration
const LANGUAGES = [
	'ar' => ['name' => 'العربية', 'locale' => 'ar', 'dir' => 'rtl'],
	'bg' => ['name' => 'Български', 'locale' => 'bg_BG', 'dir' => 'ltr'],
	'cs' => ['name' => 'čeština', 'locale' => 'cs_CZ', 'dir' => 'ltr'],
	'de' => ['name' => 'Deutsch', 'locale' => 'de_DE', 'dir' => 'ltr'],
	'en' => ['name' => 'English', 'locale' => 'en_GB', 'dir' => 'ltr'],
	'es' => ['name' => 'Español', 'locale' => 'es_ES', 'dir' => 'ltr'],
	'fi' => ['name' => 'Suomi', 'locale' => 'fi_FI', 'dir' => 'ltr'],
	'fr' => ['name' => 'Français', 'locale' => 'fr_FR', 'dir' => 'ltr'],
	'id' => ['name' => 'Bahasa Indonesia', 'locale' => 'id_ID', 'dir' => 'ltr'],
	'it' => ['name' => 'Italiano', 'locale' => 'it_IT', 'dir' => 'ltr'],
	'pt' => ['name' => 'Português', 'locale' => 'pt_PT', 'dir' => 'ltr'],
	'ru' => ['name' => 'Русский', 'locale' => 'ru_RU', 'dir' => 'ltr'],
	'tr' => ['name' => 'Türkçe', 'locale' => 'tr_TR', 'dir' => 'ltr'],
	'uk' => ['name' => 'Українська', 'locale' => 'uk_UA', 'dir' => 'ltr'],
	'zh-Hans' => ['name' => '简体中文', 'locale' => 'zh_CN', 'dir' => 'ltr'],
	'zh-Hant' => ['name' => '正體中文', 'locale' => 'zh_TW', 'dir' => 'ltr'],
];
load_config();
$U=[];// This user data
$db = null;// Database connection
$memcached = null;// Memcached connection
$language = LANG;// user selected language
$locale = LANGUAGES[LANG]['locale'];// user selected locale
$dir = LANGUAGES[LANG]['dir'];// user selected language direction
$scripts = []; //js enhancements
$styles = []; //css styles
$session = $_REQUEST['session'] ?? ''; //requested session
// set session variable to cookie if cookies are enabled
if(!isset($_REQUEST['session']) && isset($_COOKIE[COOKIENAME])){
	$session = $_COOKIE[COOKIENAME];
}
$session = preg_replace('/[^0-9a-zA-Z]/', '', $session);
load_lang();
check_db();
cron();
route();

//  main program: decide what to do based on queries
function route(): void
{
	global $U;
	if(!isset($_REQUEST['action'])){
		send_login();
	}elseif($_REQUEST['action']==='view'){
		check_session();
		send_messages();
	}elseif($_REQUEST['action']==='redirect' && !empty($_GET['url'])){
		send_redirect($_GET['url']);
	}elseif($_REQUEST['action']==='wait'){
		parse_sessions();
		send_waiting_room();
	}elseif($_REQUEST['action']==='post'){
		check_session();
		if(isset($_POST['kick']) && isset($_POST['sendto']) && $_POST['sendto']!=='s _'){
			if($U['status']>=5 || ($U['status']>=3 && (get_setting('memkickalways') || (get_count_mods()==0 && get_setting('memkick'))))){
				if(isset($_POST['what']) && $_POST['what']==='purge'){
					kick_chatter([$_POST['sendto']], $_POST['message'], true);
				}else{
					kick_chatter([$_POST['sendto']], $_POST['message'], false);
				}
			}
		}elseif(isset($_POST['message']) && isset($_POST['sendto'])){
			send_post(validate_input());
		}
		send_post();
	}elseif($_REQUEST['action']==='login'){
		check_login();
		show_fails();
		send_frameset();
	}elseif($_REQUEST['action']==='controls'){
		check_session();
		send_controls();
	}elseif($_REQUEST['action']==='greeting'){
		check_session();
		send_greeting();
	}elseif($_REQUEST['action']==='delete'){
		check_session();
		if(!isset($_POST['what'])){
		}elseif($_POST['what']==='all'){
			if(isset($_POST['confirm'])){
				del_all_messages('', (int) ($U['status']==1 ? $U['entry'] : 0));
			}else{
				send_del_confirm();
			}
		}elseif($_POST['what']==='last'){
			del_last_message();
		}
		send_post();
	}elseif($_REQUEST['action']==='profile'){
		check_session();
		$arg='';
		if(!isset($_POST['do'])){
		}elseif($_POST['do']==='save'){
			$arg=save_profile();
		}elseif($_POST['do']==='delete'){
			if(isset($_POST['confirm'])){
				delete_account();
			}else{
				send_delete_account();
			}
		}
		send_profile($arg);
	}elseif($_REQUEST['action']==='logout' && $_SERVER['REQUEST_METHOD'] === 'POST'){
		kill_session();
		send_logout();
	}elseif($_REQUEST['action']==='colours'){
		check_session();
		send_colours();
	}elseif($_REQUEST['action']==='notes'){
		check_session();
		if(!isset($_POST['do'])){
		}elseif($_POST['do']==='admin' && $U['status']>6){
			send_notes(0);
		}elseif($_POST['do']==='staff' && $U['status']>=5){
			send_notes(1);
		}elseif($_POST['do']==='public' && $U['status']>=3){
			send_notes(3);
		}
		if($U['status']<3 || (!get_setting('personalnotes') && !get_setting('publicnotes'))){
			send_access_denied();
		}
		send_notes(2);
	}elseif($_REQUEST['action']==='help'){
		check_session();
		send_help();
	}elseif($_REQUEST['action']==='viewpublicnotes'){
		check_session();
		view_publicnotes();
	}elseif($_REQUEST['action']==='inbox'){
		check_session();
		if(isset($_POST['do'])){
			clean_inbox_selected();
		}
		send_inbox();
	}elseif($_REQUEST['action']==='download'){
		send_download();
	}elseif($_REQUEST['action']==='admin'){
		check_session();
		send_admin(route_admin());
	}elseif($_REQUEST['action']==='setup'){
		route_setup();
	}elseif($_REQUEST['action']==='sa_password_reset'){
		send_sa_password_reset();
	}else{
		send_login();
	}
}

function route_admin() : string {
	global $U, $db;
	if($U['status']<5){
		send_access_denied();
	}
	if(!isset($_POST['do'])){
		return '';
	}elseif($_POST['do']==='clean'){
		if($_POST['what']==='choose'){
			send_choose_messages();
		}elseif($_POST['what']==='selected'){
			clean_selected((int) $U['status'], $U['nickname']);
		}elseif($_POST['what']==='room'){
			clean_room();
		}elseif($_POST['what']==='nick'){
			$stmt=$db->prepare('SELECT null FROM ' . PREFIX . 'members WHERE nickname=? AND status>=?;');
			$stmt->execute([$_POST['nickname'], $U['status']]);
			if(!$stmt->fetch(PDO::FETCH_ASSOC)){
				del_all_messages($_POST['nickname'], 0);
			}
		}
	}elseif($_POST['do']==='kick'){
		if(isset($_POST['name'])){
			if(isset($_POST['what']) && $_POST['what']==='purge'){
				kick_chatter($_POST['name'], $_POST['kickmessage'], true);
			}else{
				kick_chatter($_POST['name'], $_POST['kickmessage'], false);
			}
		}
	}elseif($_POST['do']==='logout'){
		if(isset($_POST['name'])){
			logout_chatter($_POST['name']);
		}
	}elseif($_POST['do']==='sessions'){
		if(isset($_POST['kick']) && isset($_POST['nick'])){
			kick_chatter([$_POST['nick']], '', false);
		}elseif(isset($_POST['logout']) && isset($_POST['nick'])){
			logout_chatter([$_POST['nick']]);
		}
		send_sessions();
	}elseif($_POST['do']==='register'){
		return register_guest(3, $_POST['name']);
	}elseif($_POST['do']==='superguest'){
		return register_guest(2, $_POST['name']);
	}elseif($_POST['do']==='status'){
		return change_status($_POST['name'], $_POST['set']);
	}elseif($_POST['do']==='regnew'){
		return register_new($_POST['name'], $_POST['pass']);
	}elseif($_POST['do']==='approve'){
		approve_session();
		send_approve_waiting();
	}elseif($_POST['do']==='guestaccess'){
		if(isset($_POST['guestaccess']) && preg_match('/^[0123]$/', $_POST['guestaccess'])){
			update_setting('guestaccess', $_POST['guestaccess']);
			change_guest_access(intval($_POST['guestaccess']));
		}
	}elseif($_POST['do']==='filter'){
		send_filter(manage_filter());
	}elseif($_POST['do']==='linkfilter'){
		send_linkfilter(manage_linkfilter());
	}elseif($_POST['do']==='topic'){
		if(isset($_POST['topic'])){
			update_setting('topic', htmlspecialchars($_POST['topic']));
		}
	}elseif($_POST['do']==='passreset'){
		return passreset($_POST['name'], $_POST['pass']);
	}
	return '';
}

function route_setup(): void
{
	global $U;
	if(!valid_admin()){
		send_alogin();
	}
	$C['bool_settings']=[
		'suguests' => _('Enable applicants'),
		'imgembed' => _('Embed images'),
		'timestamps' => _('Show Timestamps'),
		'trackip' => _('Show session-IP'),
		'memkick' => _('Members can kick, if no moderator is present'),
		'memkickalways' => _('Members can always kick'),
		'forceredirect' => _('Force redirection'),
		'incognito' => _('Incognito mode'),
		'sendmail' => _('Send mail on new public message'),
		'modfallback' => _('Fallback to waiting room, if no moderator is present to approve guests'),
		'disablepm' => _('Disable private messages'),
		'eninbox' => _('Enable offline inbox'),
		'enablegreeting' => _('Show a greeting message before showing the messages'),
		'sortupdown' => _('Sort messages from top to bottom'),
		'hidechatters' => _('Hide list of chatters'),
		'personalnotes' => _('Personal notes'),
		'publicnotes' => _('Public notes'),
		'filtermodkick' => _('Apply kick filter on moderators'),
		'namedoers' => _('Show who kicks people or purges all messages.'),
		'hide_reload_post_box' => _('Hide reload post box button'),
		'hide_reload_messages' => _('Hide reload messages button'),
		'hide_profile' => _('Hide profile button'),
		'hide_admin' => _('Hide admin button'),
		'hide_notes' => _('Hide notes button'),
		'hide_clone' => _('Hide clone button'),
		'hide_rearrange' => _('Hide rearrange button'),
		'hide_help' => _('Hide help button'),
		'postbox_delete_globally' => _('Apply postbox delete button globally'),
		'allow_js' => _('Allow enhancing functionality with JavaScript'),
	];
	$C['colour_settings']=[
		'colbg' => _('Background colour'),
		'coltxt' => _('Font colour'),
	];
	$C['msg_settings']=[
		'msgenter' => _('Entrance'),
		'msgexit' => _('Leaving'),
		'msgmemreg' => _('Member registered'),
		'msgsureg' => _('Applicant registered'),
		'msgkick' => _('Kicked'),
		'msgmultikick' => _('Multiple kicked'),
		'msgallkick' => _('All kicked'),
		'msgclean' => _('Room cleaned'),
		'msgsendall' => _('Message to all'),
		'msgsendmem' => _('Message to members only'),
		'msgsendmod' => _('Message to staff only'),
		'msgsendadm' => _('Message to admins only'),
		'msgsendprv' => _('Private message'),
		'msgattache' => _('Attachement'),
	];
	$C['number_settings']=[
		'memberexpire' => _('Member timeout (minutes)'),
		'guestexpire' => _('Guest timeout (minutes)'),
		'kickpenalty' => _('Kick penalty (minutes)'),
		'entrywait' => _('Waiting room time (seconds)'),
		'captchatime' => _('Captcha timeout (seconds)'),
		'messageexpire' => _('Message timeout (minutes)'),
		'messagelimit' => _('Message limit (public)'),
		'maxmessage' => _('Maximal message length'),
		'maxname' => _('Maximal nickname length'),
		'minpass' => _('Minimal password length'),
		'defaultrefresh' => _('Default message reload time (seconds)'),
		'numnotes' => _('Number of notes revisions to keep'),
		'maxuploadsize' => _('Maximum upload size in KB'),
		'enfileupload' => _('Enable file uploads'),
		'max_refresh_rate' => _('Lowest refresh rate'),
		'min_refresh_rate' => _('Highest refresh rate'),
	];
	$C['textarea_settings']=[
		'rulestxt' => _('Rules (html)'),
		'css' => _('CSS Style'),
		'disabletext' => _('Chat disabled message (html)'),
	];
	$C['text_settings']=[
		'dateformat' => _('<a target="_blank" href="https://php.net/manual/en/function.date.php#refsect1-function.date-parameters" rel="noopener noreferrer">Date formating</a>'),
		'captchachars' => _('Characters used in Captcha'),
		'redirect' => _('Custom redirection script'),
		'chatname' => _('Chat name'),
		'mailsender' => _('Send mail using this address'),
		'mailreceiver' => _('Send mail to this address'),
		'nickregex' => _('Nickname regex'),
		'passregex' => _('Password regex'),
		'externalcss' => _('Link to external CSS file (on your own server)'),
		'metadescription' => _('Meta description (best 50 - 160 characters for SEO)'),
		'sysmessagetxt' => _('Prepend this text to system messages'),
	];
	$extra_settings=[
		'guestaccess' => _('Change Guestaccess'),
		'englobalpass' => _('Enable global Password'),
		'globalpass' => _('Global Password:'),
		'captcha' => _('Captcha'),
		'dismemcaptcha' => _('Only for guests'),
		'topic' => _('Topic'),
		'guestreg' => _('Let guests register themselves'),
		'defaulttz' => _('Default time zone'),
	];
	$C['settings']=array_keys(array_merge($extra_settings, $C['bool_settings'], $C['colour_settings'], $C['msg_settings'], $C['number_settings'], $C['textarea_settings'], $C['text_settings'])); // All settings in the database
	if(!isset($_POST['do'])){
	}elseif($_POST['do']==='save'){
		save_setup($C);
	}elseif($_POST['do']==='backup' && $U['status']==8){
		send_backup($C);
	}elseif($_POST['do']==='restore' && $U['status']==8){
		restore_backup($C);
		send_backup($C);
	}elseif($_POST['do']==='destroy' && $U['status']==8){
		if(isset($_POST['confirm'])){
			destroy_chat($C);
		}else{
			send_destroy_chat();
		}
	}
	send_setup($C);
}

//  html output subs
function prepare_stylesheets(string $class): void
{
	global $U, $db, $scripts, $styles;
	if($class === 'fatal_error') {
		$styles[ 'fatal_error' ] = 'body{background-color:#000000;color:#FF0033}';
	}
	$styles['default'] = 'body,iframe{background-color:#000000;color:#FFFFFF;font-size:14px;text-align:center;width:100%;height:100%;margin:0;padding:0;border:none}';
	$styles['default'] .= 'a:visited{color:#B33CB4} a:link{color:#00A2D4} a:active{color:#55A2D4}';
	$styles['default'] .= 'input,select,textarea{color:#FFFFFF;background-color:#000000} ';
	$styles['default'] .= '.error{color:#FF0033;text-align:left} .delbutton{background-color:#660000} .backbutton{background-color:#004400} #exitbutton{background-color:#AA0000} ';
	$styles['default'] .= '.setup table table,.admin table table,.profile table table{width:100%;text-align:left} ';
	$styles['default'] .= '.alogin table,.init table,.destroy_chat table,.delete_account table,.sessions table,.filter table,.linkfilter table,.notes table,.approve_waiting table,.del_confirm table,.profile table,.admin table,.backup table,.setup table{margin-left:auto;margin-right:auto} ';
	$styles['default'] .= '.setup table table table,.admin table table table,.profile table table table{border-spacing:0px;margin-left:auto;margin-right:unset;width:unset} ';
	$styles['default'] .= '.setup table table td,.backup #restoresubmit,.backup #backupsubmit,.admin table table td,.profile table table td,.login td+td,.alogin td+td{text-align:right} ';
	$styles['default'] .= '.init td,.backup #restorecheck td,.admin #clean td,.admin #regnew td,.session td,.messages,.inbox,.approve_waiting td,.choose_messages,.greeting,.help,.login td,.alogin td{text-align:left} ';
	$styles['default'] .= '.approve_waiting #action td:only-child,.help #backcredit,.login td:only-child,.alogin td:only-child,.init td:only-child{text-align:center} .sessions td,.sessions th,.approve_waiting td,.approve_waiting th{padding: 5px} ';
	$styles['default'] .= '.sessions td td{padding: 1px} .notes textarea{height:80vh;width:80%} ';
	$styles['default'] .= '.post table,.controls table,.login table{border-spacing:0px;margin-left:auto;margin-right:auto} .login table{border:2px solid} .controls{overflow-y:none} ';
	if($class === 'init' || ! $db instanceof PDO){
		return;
	}
	if($class === 'frameset'){
		if(($U['status']>=5 || ($U['status']>2 && get_count_mods()==0)) && get_setting('enfileupload')>0 && get_setting('enfileupload')<=$U['status']){
			$postheight='120px';
		}else{
			$postheight='100px';
		}
		if((!isset($_REQUEST['sort']) && !$U['sortupdown']) || (isset($_REQUEST['sort']) && $_REQUEST['sort']==0)) {
			$styles[ 'frameset' ] = "#frameset-mid{position:fixed;top:$postheight;bottom:45px;left:0;right:0;margin:0;padding:0;overflow:hidden}";
			$styles[ 'frameset' ] .= "#frameset-top{position:fixed;top:0;left:0;right:0;height:$postheight;margin:0;padding:0;overflow:hidden;border-bottom: 1px solid}";
			$styles[ 'frameset' ] .= "#frameset-bot{position:fixed;bottom:0;left:0;right:0;height:45px;margin:0;padding:0;overflow:hidden;border-top:1px solid}";
		} else{
			$styles[ 'frameset' ] =" #frameset-mid{position:fixed;top:45px;bottom:$postheight;left:0;right:0;margin:0;padding:0;overflow:hidden}";
			$styles[ 'frameset' ] .= "#frameset-top{position:fixed;top:0;left:0;right:0;height:45px;margin:0;padding:0;overflow:hidden;border-bottom:1px solid}";
			$styles[ 'frameset' ] .= "#frameset-bot{position:fixed;bottom:0;left:0;right:0;height:$postheight;margin:0;padding:0;overflow:hidden;border-top:1px solid}";
		}
	}
	if($class === 'filter'){
		$styles['filter'] = 'table table{width:100%} ';
		$styles['filter'] .= 'table table td:nth-child(1){width:8em;font-weight:bold} ';
		$styles['filter'] .= 'table table td:nth-child(2),table table td:nth-child(3){width:12em} ';
		$styles['filter'] .= 'table table td:nth-child(4){width:9em} ';
		$styles['filter'] .= 'table table td:nth-child(5),table table td:nth-child(6),table table td:nth-child(7),table table td:nth-child(8){width:5em} ';
	}
	if($class === 'linkfilter'){
		$styles['linkfilter'] = 'table table{width:100%} ';
		$styles['linkfilter'] .= 'table table td:nth-child(1){width:8em;font-weight:bold} ';
		$styles['linkfilter'] .= 'table table td:nth-child(2),table table td:nth-child(3){width:12em} ';
		$styles['linkfilter'] .= 'table table td:nth-child(4),table table td:nth-child(5){width:5em} ';
	}
	if($class === 'post'){
		$styles['post'] = '.spacer{width:10px} #firstline{vertical-align:top}';
	}
	if($class === 'messages'){
		$styles['messages'] = '.nicklink{text-decoration:none}.channellink{text-decoration:underline}';
		$styles['messages'] .= '#chatters{max-height:100px;overflow-y:auto} #chatters, #chatters table{border-spacing:0px} ';
		$styles['messages'] .= '#manualrefresh{display:block;position:fixed;text-align:center;left:25%;width:50%;top:-200%;animation:timeout_messages ';
		$styles['messages'] .= $U['refresh']+20;
		$styles['messages'] .= 's forwards;z-index:2;background-color:#500000;border:2px solid #ff0000} ';
		$styles['messages'] .= '@keyframes timeout_messages{0%{top:-200%} 99%{top:-200%} 100%{top:0%}} ';
		$styles['messages'] .= '.msg{max-height:180px;overflow-y:auto} #bottom_link{position:fixed;top:0.5em;right:0.5em} #top_link{position:fixed;bottom:0.5em;right:0.5em} ';
		$styles['messages'] .= '#chatters th,#chatters td{vertical-align:top} a img{width:15%} a:hover img{width:35%}';
		$styles['messages'] .= '#messages{word-wrap:break-word}';
	}
	$css=get_setting('css');
	$coltxt=get_setting('coltxt');
	if(!empty($U['bgcolour'])){
		$colbg=$U['bgcolour'];
	}else{
		$colbg=get_setting('colbg');
	}
	$styles['custom'] = preg_replace("/(\r?\n|\r\n?)/u", '', "body,iframe{background-color:#$colbg;color:#$coltxt} $css");
	$allow_js = (bool) get_setting('allow_js');
	if($allow_js){
		$scripts['default'] = 'if(window.history.replaceState){window.history.replaceState(null,"");}';
		if($class === 'frameset') {
			$scripts[ 'frameset' ] = 'window.addEventListener("message", (e)=>{
				if(e.data === "post_box_loaded"){
					let autofocus = document.querySelector("iframe[name=post").contentDocument.querySelector("input[autofocus]");
					if(autofocus){
						autofocus.focus();
					}
				}
			});';
		}
		if($class === 'post') {
			$scripts[ 'post' ] = 'window.addEventListener("load", _=>{
				window.top.postMessage("post_box_loaded", window.location.origin);
			})';
		}
	}
}

function print_stylesheet(string $class): void
{
	global $scripts, $styles;
	//default css
	echo "<style>$styles[default]</style>";
	if ( $class === 'init' ) {
		return;
	}
	if(isset($styles[$class])) {
		echo "<style>$styles[$class]</style>";
	}
	//overwrite with custom css
	echo "<style>$styles[custom]</style>";
	$allow_js = (bool) get_setting( 'allow_js' );
	if ( $allow_js ) {
		echo "<script>$scripts[default]</script>";
		if(isset($scripts[$class])) {
			echo "<script>$scripts[$class]</script>";
		}
	}
}

function print_end(): void
{
	echo '</body></html>';
	exit;
}

function credit() : string {
	return '<small><br><br><a target="_blank" href="https://github.com/DanWin/le-chat-php" rel="noreferrer noopener">LE CHAT-PHP - ' . VERSION . '</a></small>';
}

function meta_html() : string {
	global $U, $db;
	$colbg = '000000';
	$description = '';
	if(!empty($U['bgcolour'])){
		$colbg = $U['bgcolour'];
	}else{
		if($db instanceof PDO){
			$colbg = get_setting('colbg');
			$description = '<meta name="description" content="'.htmlspecialchars(get_setting('metadescription')).'">';
		}
	}
	return '<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta name="referrer" content="no-referrer"><meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=yes"><meta name="theme-color" content="#'.$colbg.'"><meta name="msapplication-TileColor" content="#'.$colbg.'">' . $description;
}

function form(string $action, string $do='') : string {
	global $language, $session;
	$form="<form action=\"$_SERVER[SCRIPT_NAME]\" enctype=\"multipart/form-data\" method=\"post\">".hidden('lang', $language).hidden('nc', substr(time(), -6)).hidden('action', $action);
	if(!empty($session)){
		$form.=hidden('session', $session);
	}
	if($do!==''){
		$form.=hidden('do', $do);
	}
	return $form;
}

function form_target(string $target, string $action, string $do='') : string {
	global $language, $session;
	$form="<form action=\"$_SERVER[SCRIPT_NAME]\" enctype=\"multipart/form-data\" method=\"post\" target=\"$target\">".hidden('lang', $language).hidden('nc', substr(time(), -6)).hidden('action', $action);
	if(!empty($session)){
		$form.=hidden('session', $session);
	}
	if($do!==''){
		$form.=hidden('do', $do);
	}
	return $form;
}

function hidden(string $name='', string $value='') : string {
	return "<input type=\"hidden\" name=\"$name\" value=\"$value\">";
}

function submit(string $value='', string $extra_attribute='') : string {
	return "<input type=\"submit\" value=\"$value\" $extra_attribute>";
}

function thr(): void
{
	echo '<tr><td><hr></td></tr>';
}

function print_start(string $class='', int $ref=0, string $url=''): void
{
	global $language, $dir;
	prepare_stylesheets($class);
	send_headers();
	if(!empty($url)){
		$url=str_replace('&amp;', '&', $url);// Don't escape "&" in URLs here, it breaks some (older) browsers and js refresh!
		header("Refresh: $ref; URL=$url");
	}
	echo '<!DOCTYPE html><html lang="'.$language.'" dir="'.$dir.'"><head>'.meta_html();
	if(!empty($url)){
		echo "<meta http-equiv=\"Refresh\" content=\"$ref; URL=$url\">";
	}
	if($class==='init'){
		echo '<title>'._('Initial Setup').'</title>';
	}else{
		echo '<title>'.get_setting('chatname').'</title>';
	}
	print_stylesheet($class);
	echo "</head><body class=\"$class\">";
	if($class!=='init' && ($externalcss=get_setting('externalcss'))!=''){
		//external css - in body to make it non-renderblocking
		echo "<link rel=\"stylesheet\" type=\"text/css\" href=\"$externalcss\">";
	}
}

function send_redirect(string $url): void
{
	$url=trim(htmlspecialchars_decode(rawurldecode($url)));
	preg_match('~^(.*)://~u', $url, $match);
	$url=preg_replace('~^(.*)://~u', '', $url);
	$escaped=htmlspecialchars($url);
	if(isset($match[1]) && ($match[1]==='http' || $match[1]==='https')){
		print_start('redirect', 0, $match[0].$escaped);
		echo '<p>'.sprintf(_('Redirecting to: %s'), "<a href=\"$match[0]$escaped\">$match[0]$escaped</a>").'</p>';
	}else{
		print_start('redirect');
		if(!isset($match[0])){
			$match[0]='';
		}
		if(preg_match('~^(javascript|blob|data):~', $url)){
			echo '<p>'.sprintf(_('Dangerous non-http link requested, copy paste this link if you are really sure: %s'), "$match[0]$escaped").'</p>';
		} else {
			echo '<p>'.sprintf(_('Non-http link requested: %s'), "<a href=\"$match[0]$escaped\">$match[0]$escaped</a>").'</p>';
		}
		echo '<p>'.sprintf(_("If it's not working, try this one: %s"), "<a href=\"http://$escaped\">http://$escaped</a>").'</p>';
	}
	print_end();
}

function send_access_denied(): void
{
	global $U;
	http_response_code(403);
	print_start('access_denied');
	echo '<h1>'._('Access denied').'</h1>'.sprintf(_("You are logged in as %s and don't have access to this section."), style_this(htmlspecialchars($U['nickname']), $U['style'])).'<br>';
	echo form('logout');
	echo submit(_('Logout'), 'id="exitbutton"')."</form>";
	print_end();
}

function send_captcha(): void
{
	global $db, $memcached;
	$difficulty=(int) get_setting('captcha');
	if($difficulty===0 || !extension_loaded('gd')){
		return;
	}
	$captchachars=get_setting('captchachars');
	$length=strlen($captchachars)-1;
	$code='';
	for($i=0;$i<5;++$i){
		$code.=$captchachars[mt_rand(0, $length)];
	}
	$randid=mt_rand();
	$time=time();
	if(MEMCACHED){
		$memcached->set(DBNAME . '-' . PREFIX . "captcha-$randid", $code, get_setting('captchatime'));
	}else{
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'captcha (id, time, code) VALUES (?, ?, ?);');
		$stmt->execute([$randid, $time, $code]);
	}
	echo '<tr id="captcha"><td>'._('Copy:').'<br>';
	if($difficulty===1){
		$im=imagecreatetruecolor(55, 24);
		$bg=imagecolorallocate($im, 0, 0, 0);
		$fg=imagecolorallocate($im, 255, 255, 255);
		imagefill($im, 0, 0, $bg);
		imagestring($im, 5, 5, 5, $code, $fg);
		echo '<img alt="" width="55" height="24" src="data:image/gif;base64,';
	}elseif($difficulty===2){
		$im=imagecreatetruecolor(55, 24);
		$bg=imagecolorallocate($im, 0, 0, 0);
		$fg=imagecolorallocate($im, 255, 255, 255);
		imagefill($im, 0, 0, $bg);
		imagestring($im, 5, 5, 5, $code, $fg);
		$line=imagecolorallocate($im, 255, 255, 255);
		for($i=0;$i<2;++$i){
			imageline($im, 0, mt_rand(0, 24), 55, mt_rand(0, 24), $line);
		}
		$dots=imagecolorallocate($im, 255, 255, 255);
		for($i=0;$i<100;++$i){
			imagesetpixel($im, mt_rand(0, 55), mt_rand(0, 24), $dots);
		}
		echo '<img alt="" width="55" height="24" src="data:image/gif;base64,';
	}else{
		$im=imagecreatetruecolor(150, 200);
		$bg=imagecolorallocate($im, 0, 0, 0);
		$fg=imagecolorallocate($im, 255, 255, 255);
		imagefill($im, 0, 0, $bg);
		$chars=[];
		$x = $y = 0;
		for($i=0;$i<10;++$i){
			$found=false;
			while(!$found){
				$x=mt_rand(10, 140);
				$y=mt_rand(10, 180);
				$found=true;
				foreach($chars as $char){
					if($char['x']>=$x && ($char['x']-$x)<25){
						$found=false;
					}elseif($char['x']<$x && ($x-$char['x'])<25){
						$found=false;
					}
					if(!$found){
						if($char['y']>=$y && ($char['y']-$y)<25){
							break;
						}elseif($char['y']<$y && ($y-$char['y'])<25){
							break;
						}else{
							$found=true;
						}
					}
				}
			}
			$chars[]=['x', 'y'];
			$chars[$i]['x']=$x;
			$chars[$i]['y']=$y;
			if($i<5){
				imagechar($im, 5, $chars[$i]['x'], $chars[$i]['y'], $captchachars[mt_rand(0, $length)], $fg);
			}else{
				imagechar($im, 5, $chars[$i]['x'], $chars[$i]['y'], $code[$i-5], $fg);
			}
		}
		$follow=imagecolorallocate($im, 200, 0, 0);
		imagearc($im, $chars[5]['x']+4, $chars[5]['y']+8, 16, 16, 0, 360, $follow);
		for($i=5;$i<9;++$i){
			imageline($im, $chars[$i]['x']+4, $chars[$i]['y']+8, $chars[$i+1]['x']+4, $chars[$i+1]['y']+8, $follow);
		}
		$line=imagecolorallocate($im, 255, 255, 255);
		for($i=0;$i<5;++$i){
			imageline($im, 0, mt_rand(0, 200), 150, mt_rand(0, 200), $line);
		}
		$dots=imagecolorallocate($im, 255, 255, 255);
		for($i=0;$i<1000;++$i){
			imagesetpixel($im, mt_rand(0, 150), mt_rand(0, 200), $dots);
		}
		echo '<img alt="" width="150" height="200" src="data:image/gif;base64,';
	}
	ob_start();
	imagegif($im);
	imagedestroy($im);
	echo base64_encode(ob_get_clean()).'">';
	echo '</td><td>'.hidden('challenge', $randid).'<input type="text" name="captcha" size="15" autocomplete="off" required></td></tr>';
}

function send_setup(array $C): void
{
	global $U;
	print_start('setup');
	echo '<h2>'._('Chat Setup').'</h2>'.form('setup', 'save');
	echo '<table id="guestaccess">';
	thr();
	$ga=(int) get_setting('guestaccess');
	echo '<tr><td><table><tr><th>'._('Change Guestaccess').'</th><td>';
	echo '<select name="guestaccess">';
	echo '<option value="1"';
	if($ga===1){
		echo ' selected';
	}
	echo '>'._('Allow').'</option>';
	echo '<option value="2"';
	if($ga===2){
		echo ' selected';
	}
	echo '>'._('Allow with waitingroom').'</option>';
	echo '<option value="3"';
	if($ga===3){
		echo ' selected';
	}
	echo '>'._('Require moderator approval').'</option>';
	echo '<option value="0"';
	if($ga===0){
		echo ' selected';
	}
	echo '>'._('Only members').'</option>';
	echo '<option value="4"';
	if($ga===4){
		echo ' selected';
	}
	echo '>'._('Disable chat').'</option>';
	echo '</select></td></tr></table></td></tr>';
	thr();
	$englobal=(int) get_setting('englobalpass');
	echo '<tr><td><table id="globalpass"><tr><th>'._('Global Password:').'</th><td>';
	echo '<table>';
	echo '<tr><td><select name="englobalpass">';
	echo '<option value="0"';
	if($englobal===0){
		echo ' selected';
	}
	echo '>'._('Disabled').'</option>';
	echo '<option value="1"';
	if($englobal===1){
		echo ' selected';
	}
	echo '>'._('Enabled').'</option>';
	echo '<option value="2"';
	if($englobal===2){
		echo ' selected';
	}
	echo '>'._('Only for guests').'</option>';
	echo '</select></td><td>&nbsp;</td>';
	echo '<td><input type="text" name="globalpass" value="'.htmlspecialchars(get_setting('globalpass')).'"></td></tr>';
	echo '</table></td></tr></table></td></tr>';
	thr();
	$ga=(int) get_setting('guestreg');
	echo '<tr><td><table id="guestreg"><tr><th>'._('Let guests register themselves').'</th><td>';
	echo '<select name="guestreg">';
	echo '<option value="0"';
	if($ga===0){
		echo ' selected';
	}
	echo '>'._('Disabled').'</option>';
	echo '<option value="1"';
	if($ga===1){
		echo ' selected';
	}
	echo '>'._('As applicant').'</option>';
	echo '<option value="2"';
	if($ga===2){
		echo ' selected';
	}
	echo '>'._('As member').'</option>';
	echo '</select></td></tr></table></td></tr>';
	thr();
	echo '<tr><td><table id="sysmessages"><tr><th>'._('System messages').'</th><td>';
	echo '<table>';
	foreach($C['msg_settings'] as $setting => $title){
		echo "<tr><td>&nbsp;$title</td><td>&nbsp;<input type=\"text\" name=\"$setting\" value=\"".get_setting($setting).'"></td></tr>';
	}
	echo '</table></td></tr></table></td></tr>';
	foreach($C['text_settings'] as $setting => $title){
		thr();
		echo "<tr><td><table id=\"$setting\"><tr><th>".$title.'</th><td>';
		echo "<input type=\"text\" name=\"$setting\" value=\"".htmlspecialchars(get_setting($setting)).'">';
		echo '</td></tr></table></td></tr>';
	}
	foreach($C['colour_settings'] as $setting => $title){
		thr();
		echo "<tr><td><table id=\"$setting\"><tr><th>".$title.'</th><td>';
		echo "<input type=\"color\" name=\"$setting\" value=\"#".htmlspecialchars(get_setting($setting)).'">';
		echo '</td></tr></table></td></tr>';
	}
	thr();
	echo '<tr><td><table id="captcha"><tr><th>'._('Captcha').'</th><td>';
	echo '<table>';
	if(!extension_loaded('gd')){
		echo '<tr><td>'.sprintf(_('The %s extension of PHP is required for this feature. Please install it first.'), 'gd').'</td></tr>';
	}else{
		echo '<tr><td><select name="dismemcaptcha">';
		$dismemcaptcha=(bool) get_setting('dismemcaptcha');
		echo '<option value="0"';
		if(!$dismemcaptcha){
			echo ' selected';
		}
		echo '>'._('Enabled').'</option>';
		echo '<option value="1"';
		if($dismemcaptcha){
			echo ' selected';
		}
		echo '>'._('Only for guests').'</option>';
		echo '</select></td><td><select name="captcha">';
		$captcha=(int) get_setting('captcha');
		echo '<option value="0"';
		if($captcha===0){
			echo ' selected';
		}
		echo '>'._('Disabled').'</option>';
		echo '<option value="1"';
		if($captcha===1){
			echo ' selected';
		}
		echo '>'._('Simple').'</option>';
		echo '<option value="2"';
		if($captcha===2){
			echo ' selected';
		}
		echo '>'._('Moderate').'</option>';
		echo '<option value="3"';
		if($captcha===3){
			echo ' selected';
		}
		echo '>'._('Extreme').'</option>';
		echo '</select></td></tr>';
	}
	echo '</table></td></tr></table></td></tr>';
	thr();
	echo '<tr><td><table id="defaulttz"><tr><th>'._('Default time zone').'</th><td>';
	echo '<select name="defaulttz">';
	$tzs=timezone_identifiers_list();
	$defaulttz=get_setting('defaulttz');
	foreach($tzs as $tz){
		echo "<option value=\"$tz\"";
		if($defaulttz==$tz){
			echo ' selected';
		}
		echo ">$tz</option>";
	}
	echo '</select>';
	echo '</td></tr></table></td></tr>';
	foreach($C['textarea_settings'] as $setting => $title){
		thr();
		echo "<tr><td><table id=\"$setting\"><tr><th>".$title.'</th><td>';
		echo "<textarea name=\"$setting\" rows=\"4\" cols=\"60\">".htmlspecialchars(get_setting($setting)).'</textarea>';
		echo '</td></tr></table></td></tr>';
	}
	foreach($C['number_settings'] as $setting => $title){
		thr();
		echo "<tr><td><table id=\"$setting\"><tr><th>".$title.'</th><td>';
		echo "<input type=\"number\" name=\"$setting\" value=\"".htmlspecialchars(get_setting($setting)).'">';
		echo '</td></tr></table></td></tr>';
	}
	foreach($C['bool_settings'] as $setting => $title){
		thr();
		echo "<tr><td><table id=\"$setting\"><tr><th>".$title.'</th><td>';
		echo "<select name=\"$setting\">";
		$value=(bool) get_setting($setting);
		echo '<option value="0"';
		if(!$value){
			echo ' selected';
		}
		echo '>'._('Disabled').'</option>';
		echo '<option value="1"';
		if($value){
			echo ' selected';
		}
		echo '>'._('Enabled').'</option>';
		echo '</select></td></tr>';
		echo '</table></td></tr>';
	}
	thr();
	echo '<tr><td>'.submit(_('Apply')).'</td></tr></table></form><br>';
	if($U['status']==8){
		echo '<table id="actions"><tr><td>';
		echo form('setup', 'backup');
		echo submit(_('Backup and restore')).'</form></td><td>';
		echo form('setup', 'destroy');
		echo submit(_('Destroy chat'), 'class="delbutton"').'</form></td></tr></table><br>';
	}
	echo form_target('_parent', 'logout');
	echo submit(_('Logout'), 'id="exitbutton"').'</form>'.credit();
	print_end();
}

function restore_backup(array $C): void
{
	global $db, $memcached;
	if(!extension_loaded('json')){
		return;
	}
	$code=json_decode($_POST['restore'], true);
	if(isset($_POST['settings'])){
		foreach($C['settings'] as $setting){
			if(isset($code['settings'][$setting])){
				update_setting($setting, $code['settings'][$setting]);
			}
		}
	}
	if(isset($_POST['filter']) && (isset($code['filters']) || isset($code['linkfilters']))){
		$db->exec('DELETE FROM ' . PREFIX . 'filter;');
		$db->exec('DELETE FROM ' . PREFIX . 'linkfilter;');
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'filter (filtermatch, filterreplace, allowinpm, regex, kick, cs) VALUES (?, ?, ?, ?, ?, ?);');
		foreach($code['filters'] as $filter){
			if(!isset($filter['cs'])){
				$filter['cs']=0;
			}
			$stmt->execute([$filter['match'], $filter['replace'], $filter['allowinpm'], $filter['regex'], $filter['kick'], $filter['cs']]);
		}
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'linkfilter (filtermatch, filterreplace, regex) VALUES (?, ?, ?);');
		foreach($code['linkfilters'] as $filter){
			$stmt->execute([$filter['match'], $filter['replace'], $filter['regex']]);
		}
		if(MEMCACHED){
			$memcached->delete(DBNAME . '-' . PREFIX . 'filter');
			$memcached->delete(DBNAME . '-' . PREFIX . 'linkfilter');
		}
	}
	if(isset($_POST['members']) && isset($code['members'])){
		$db->exec('DELETE FROM ' . PREFIX . 'inbox;');
		$db->exec('DELETE FROM ' . PREFIX . 'members;');
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'members (nickname, passhash, status, refresh, bgcolour, regedby, lastlogin, loginfails, timestamps, embed, incognito, style, nocache, tz, eninbox, sortupdown, hidechatters, nocache_old) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);');
		foreach($code['members'] as $member){
			$new_settings=['nocache', 'tz', 'eninbox', 'sortupdown', 'hidechatters', 'nocache_old'];
			foreach($new_settings as $setting){
				if(!isset($member[$setting])){
					$member[$setting]=0;
				}
			}
			$stmt->execute([$member['nickname'], $member['passhash'], $member['status'], $member['refresh'], $member['bgcolour'], $member['regedby'], $member['lastlogin'], $member['loginfails'], $member['timestamps'], $member['embed'], $member['incognito'], $member['style'], $member['nocache'], $member['tz'], $member['eninbox'], $member['sortupdown'], $member['hidechatters'], $member['nocache_old']]);
		}
	}
	if(isset($_POST['notes']) && isset($code['notes'])){
		$db->exec('DELETE FROM ' . PREFIX . 'notes;');
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'notes (type, lastedited, editedby, text) VALUES (?, ?, ?, ?);');
		foreach($code['notes'] as $note){
			if($note['type']==='admin'){
				$note['type']=0;
			}elseif($note['type']==='staff'){
				$note['type']=1;
			}elseif($note['type']==='public'){
				$note['type']=3;
			}
			if(MSGENCRYPTED){
				try {
					$note['text']=base64_encode(sodium_crypto_aead_aes256gcm_encrypt($note['text'], '', AES_IV, ENCRYPTKEY));
				} catch (SodiumException $e){
					send_error($e->getMessage());
				}
			}
			$stmt->execute([$note['type'], $note['lastedited'], $note['editedby'], $note['text']]);
		}
	}
}

function send_backup(array $C): void
{
	global $db;
	$code=[];
	if($_POST['do']==='backup'){
		if(isset($_POST['settings'])){
			foreach($C['settings'] as $setting){
				$code['settings'][$setting]=get_setting($setting);
			}
		}
		if(isset($_POST['filter'])){
			$result=$db->query('SELECT * FROM ' . PREFIX . 'filter;');
			while($filter=$result->fetch(PDO::FETCH_ASSOC)){
				$code['filters'][]=['match'=>$filter['filtermatch'], 'replace'=>$filter['filterreplace'], 'allowinpm'=>$filter['allowinpm'], 'regex'=>$filter['regex'], 'kick'=>$filter['kick'], 'cs'=>$filter['cs']];
			}
			$result=$db->query('SELECT * FROM ' . PREFIX . 'linkfilter;');
			while($filter=$result->fetch(PDO::FETCH_ASSOC)){
				$code['linkfilters'][]=['match'=>$filter['filtermatch'], 'replace'=>$filter['filterreplace'], 'regex'=>$filter['regex']];
			}
		}
		if(isset($_POST['members'])){
			$result=$db->query('SELECT * FROM ' . PREFIX . 'members;');
			while($member=$result->fetch(PDO::FETCH_ASSOC)){
				$code['members'][]=$member;
			}
		}
		if(isset($_POST['notes'])){
			$result=$db->query('SELECT * FROM ' . PREFIX . "notes;");
			while($note=$result->fetch(PDO::FETCH_ASSOC)){
				if(MSGENCRYPTED){
					try {
						$note['text']=sodium_crypto_aead_aes256gcm_decrypt(base64_decode($note['text']), null, AES_IV, ENCRYPTKEY);
					} catch (SodiumException $e){
						send_error($e->getMessage());
					}
				}
				$code['notes'][]=$note;
			}
		}
	}
	if(isset($_POST['settings'])){
		$chksettings=' checked';
	}else{
		$chksettings='';
	}
	if(isset($_POST['filter'])){
		$chkfilters=' checked';
	}else{
		$chkfilters='';
	}
	if(isset($_POST['members'])){
		$chkmembers=' checked';
	}else{
		$chkmembers='';
	}
	if(isset($_POST['notes'])){
		$chknotes=' checked';
	}else{
		$chknotes='';
	}
	print_start('backup');
	echo '<h2>'._('Backup and restore').'</h2><table>';
	thr();
	if(!extension_loaded('json')){
		echo '<tr><td>'.sprintf(_('The %s extension of PHP is required for this feature. Please install it first.'), 'json').'</td></tr>';
	}else{
		echo '<tr><td>'.form('setup', 'backup');
		echo '<table id="backup"><tr><td id="backupcheck">';
		echo '<label><input type="checkbox" name="settings" id="backupsettings" value="1"'.$chksettings.'>'._('Settings').'</label>';
		echo '<label><input type="checkbox" name="filter" id="backupfilter" value="1"'.$chkfilters.'>'._('Filter').'</label>';
		echo '<label><input type="checkbox" name="members" id="backupmembers" value="1"'.$chkmembers.'>'._('Members').'</label>';
		echo '<label><input type="checkbox" name="notes" id="backupnotes" value="1"'.$chknotes.'>'._('Notes').'</label>';
		echo '</td><td id="backupsubmit">'.submit(_('Backup')).'</td></tr></table></form></td></tr>';
		thr();
		echo '<tr><td>'.form('setup', 'restore');
		echo '<table id="restore">';
		echo '<tr><td colspan="2"><textarea name="restore" rows="4" cols="60">'.htmlspecialchars(json_encode($code)).'</textarea></td></tr>';
		echo '<tr><td id=\"restorecheck\"><label><input type="checkbox" name="settings" id="restoresettings" value="1"'.$chksettings.'>'._('Settings').'</label>';
		echo '<label><input type="checkbox" name="filter" id="restorefilter" value="1"'.$chkfilters.'>'._('Filter').'</label>';
		echo '<label><input type="checkbox" name="members" id="restoremembers" value="1"'.$chkmembers.'>'._('Members').'</label>';
		echo '<label><input type="checkbox" name="notes" id="restorenotes" value="1"'.$chknotes.'>'._('Notes').'</label>';
		echo '</td><td id="restoresubmit">'.submit(_('Restore')).'</td></tr></table>';
		echo '</form></td></tr>';
	}
	thr();
	echo '<tr><td>'.form('setup').submit(_('Go to the Setup-Page'), 'class="backbutton"')."</form></tr></td>";
	echo '</table>';
	print_end();
}

function send_destroy_chat(): void
{
	print_start('destroy_chat');
	echo '<table><tr><td colspan="2">'._('Are you sure?').'</td></tr><tr><td>';
	echo form_target('_parent', 'setup', 'destroy').hidden('confirm', 'yes').submit(_('Yes'), 'class="delbutton"').'</form></td><td>';
	echo form('setup').submit(_('No'), 'class="backbutton"').'</form></td><tr></table>';
	print_end();
}

function send_delete_account(): void
{
	print_start('delete_account');
	echo '<table><tr><td colspan="2">'._('Are you sure?').'</td></tr><tr><td>';
	echo form('profile', 'delete').hidden('confirm', 'yes').submit(_('Yes'), 'class="delbutton"').'</form></td><td>';
	echo form('profile').submit(_('No'), 'class="backbutton"').'</form></td><tr></table>';
	print_end();
}

function send_init(): void
{
	print_start('init');
	echo '<h2>'._('Initial Setup').'</h2>';
	echo form('init').'<table><tr><td><h3>'._('Superadmin Login').'</h3><table>';
	echo '<tr><td>'._('Superadmin Nickname:').'</td><td><input type="text" name="sunick" size="15" autocomplete="username"></td></tr>';
	echo '<tr><td>'._('Superadmin Password:').'</td><td><input type="password" name="supass" size="15" autocomplete="new-password"></td></tr>';
	echo '<tr><td>'._('Confirm Password:').'</td><td><input type="password" name="supassc" size="15" autocomplete="new-password"></td></tr>';
	echo '</table></td></tr><tr><td><br>'.submit(_('Initialise Chat')).'</td></tr></table></form>';
	echo '<p id="changelang">'._('Change language:');
	foreach(LANGUAGES as $lang=>$data){
		echo " <a href=\"$_SERVER[SCRIPT_NAME]?action=setup&amp;lang=$lang\">$data[name]</a>";
	}
	echo '</p>'.credit();
	print_end();
}

function send_update(string $msg): void
{
	print_start('update');
	echo '<h2>'._('Database successfully updated!',).'</h2><br>'.form('setup').submit(_('Go to the Setup-Page'))."</form>$msg<br>".credit();
	print_end();
}

function send_alogin(): void
{
	print_start('alogin');
	echo form('setup').'<table>';
	echo '<tr><td>'._('Nickname:').'</td><td><input type="text" name="nick" size="15" autocomplete="username" autofocus></td></tr>';
	echo '<tr><td>'._('Password:').'</td><td><input type="password" name="pass" size="15" autocomplete="current-password"></td></tr>';
	send_captcha();
	echo '<tr><td colspan="2">'.submit(_('Login')).'</td></tr></table></form>';
	echo '<br><a href="?action=sa_password_reset">'._('Forgot login?').'</a><br>';
	echo '<p id="changelang">'._('Change language:');
	foreach(LANGUAGES as $lang=>$data){
		echo " <a href=\"?action=setup&amp;lang=$lang\" hreflang=\"$lang\">$data[name]</a>";
	}
	echo '</p>'.credit();
	print_end();
}

function send_sa_password_reset(): void
{
	global $db;
	print_start('sa_password_reset');
	echo '<h1>'._('Reset password').'</h1>';
	if(defined('RESET_SUPERADMIN_PASSWORD') && !empty(RESET_SUPERADMIN_PASSWORD)){
		$stmt = $db->query('SELECT nickname FROM ' . PREFIX . 'members WHERE status = 8 LIMIT 1;');
		if($user = $stmt->fetch(PDO::FETCH_ASSOC)){
			$mem_update = $db->prepare('UPDATE ' . PREFIX . 'members SET passhash = ? WHERE nickname = ? LIMIT 1;');
			$mem_update->execute([password_hash(RESET_SUPERADMIN_PASSWORD, PASSWORD_DEFAULT), $user['nickname']]);
			$sess_delete = $db->prepare('DELETE FROM ' . PREFIX . 'sessions WHERE nickname = ?;');
			$sess_delete->execute([$user['nickname']]);
			printf('<p>'._('Successfully reset password for username %s. Please remove the password reset define from the script again.').'</p>', $user['nickname']);
		}
	} else {
		echo '<p>'._("Please modify the script and put the following at the bottom of it (change the password). Then refresh this page: define('RESET_SUPERADMIN_PASSWORD', 'changeme');").'</p>';
	}
	echo '<a href="?action=setup">'._('Go to the Setup-Page').'</a>';
	echo '<p id="changelang">'._('Change language:');
	foreach(LANGUAGES as $lang=>$data){
		echo " <a href=\"?action=sa_password_reset&amp;lang=$lang\" hreflang=\"$lang\">$data[name]</a>";
	}
	echo '</p>'.credit();
	print_end();
}

function send_admin(string $arg): void
{
	global $U, $db;
	$ga=(int) get_setting('guestaccess');
	print_start('admin');
	$chlist='<select name="name[]" size="5" multiple><option value="">'._('(choose)').'</option>';
	$chlist.='<option value="s &#42;">'._('All guests').'</option>';
	$users=[];
	$stmt=$db->query('SELECT nickname, style, status FROM ' . PREFIX . 'sessions WHERE entry!=0 AND status>0 ORDER BY LOWER(nickname);');
	while($user=$stmt->fetch(PDO::FETCH_NUM)){
		$users[]=[htmlspecialchars($user[0]), $user[1], $user[2]];
	}
	foreach($users as $user){
		if($user[2]<$U['status']){
			$chlist.="<option value=\"$user[0]\" style=\"$user[1]\">$user[0]</option>";
		}
	}
	$chlist.='</select>';
	echo '<h2>'._('Administrative functions')."</h2><i>$arg</i><table>";
	if($U['status']>=7){
		thr();
		echo '<tr><td>'.form_target('view', 'setup').submit(_('Go to the Setup-Page')).'</form></td></tr>';
	}
	thr();
	echo '<tr><td><table id="clean"><tr><th>'._('Clean messages').'</th><td>';
	echo form('admin', 'clean');
	echo '<table><tr><td><label><input type="radio" name="what" id="room" value="room">';
	echo _('Whole room').'</label></td><td>&nbsp;</td><td><label><input type="radio" name="what" id="choose" value="choose" checked>';
	echo _('Selection').'</label></td><td>&nbsp;</td></tr><tr><td colspan="3"><label><input type="radio" name="what" id="nick" value="nick">';
	echo _('Following nickname:').'</label> <select name="nickname" size="1"><option value="">'._('(choose)').'</option>';
	$stmt=$db->prepare('SELECT DISTINCT poster FROM ' . PREFIX . "messages WHERE delstatus<? AND poster!='';");
	$stmt->execute([$U['status']]);
	while($nick=$stmt->fetch(PDO::FETCH_NUM)){
		echo '<option value="'.htmlspecialchars($nick[0]).'">'.htmlspecialchars($nick[0]).'</option>';
	}
	echo '</select></td><td>';
	echo submit(_('Clean'), 'class="delbutton"').'</td></tr></table></form></td></tr></table></td></tr>';
	thr();
	echo '<tr><td><table id="kick"><tr><th>'.sprintf(_('Kick Chatter (%d minutes)'), get_setting('kickpenalty')).'</th></tr><tr><td>';
	echo form('admin', 'kick');
	echo '<table><tr><td>'._('Kickmessage:').'</td><td><input type="text" name="kickmessage" size="30"></td><td>&nbsp;</td></tr>';
	echo '<tr><td><label><input type="checkbox" name="what" value="purge" id="purge">'._('Purge messages').'</label></td><td>'.$chlist.'</td><td>';
	echo submit(_('Kick')).'</td></tr></table></form></td></tr></table></td></tr>';
	thr();
	echo '<tr><td><table id="logout"><tr><th>'._('Logout inactive Chatter').'</th><td>';
	echo form('admin', 'logout');
	echo "<table><tr><td>$chlist</td><td>";
	echo submit(_('Logout')).'</td></tr></table></form></td></tr></table></td></tr>';
	$views=['sessions' => _('View active sessions'), 'filter' => _('Filter'), 'linkfilter' => _('Linkfilter')];
	foreach($views as $view => $title){
		thr();
		echo "<tr><td><table id=\"$view\"><tr><th>".$title.'</th><td>';
		echo form('admin', $view);
		echo submit(_('View')).'</form></td></tr></table></td></tr>';
	}
	thr();
	echo '<tr><td><table id="topic"><tr><th>'._('Topic').'</th><td>';
	echo form('admin', 'topic');
	echo '<table><tr><td><input type="text" name="topic" size="20" value="'.get_setting('topic').'"></td><td>';
	echo submit(_('Change')).'</td></tr></table></form></td></tr></table></td></tr>';
	thr();
	echo '<tr><td><table id="guestaccess"><tr><th>'._('Change Guestaccess').'</th><td>';
	echo form('admin', 'guestaccess');
	echo '<table>';
	echo '<tr><td><select name="guestaccess">';
	echo '<option value="1"';
	if($ga===1){
		echo ' selected';
	}
	echo '>'._('Allow').'</option>';
	echo '<option value="2"';
	if($ga===2){
		echo ' selected';
	}
	echo '>'._('Allow with waitingroom').'</option>';
	echo '<option value="3"';
	if($ga===3){
		echo ' selected';
	}
	echo '>'._('Require moderator approval').'</option>';
	echo '<option value="0"';
	if($ga===0){
		echo ' selected';
	}
	echo '>'._('Only members').'</option>';
	if($ga===4){
		echo '<option value="4" selected';
		echo '>'._('Disable chat').'</option>';
	}
	echo '</select></td><td>'.submit(_('Change')).'</td></tr></table></form></td></tr></table></td></tr>';
	thr();
	if(get_setting('suguests')){
		echo '<tr><td><table id="suguests"><tr><th>'._('Register applicant').'</th><td>';
		echo form('admin', 'superguest');
		echo '<table><tr><td><select name="name" size="1"><option value="">'._('(choose)').'</option>';
		foreach($users as $user){
			if($user[2]==1){
				echo "<option value=\"$user[0]\" style=\"$user[1]\">$user[0]</option>";
			}
		}
		echo '</select></td><td>'.submit(_('Register')).'</td></tr></table></form></td></tr></table></td></tr>';
		thr();
	}
	if($U['status']>=7){
		echo '<tr><td><table id="status"><tr><th>'._('Members').'</th><td>';
		echo form('admin', 'status');
		echo '<table><tr><td><select name="name" size="1"><option value="">'._('(choose)').'</option>';
		$members=[];
		$result=$db->query('SELECT nickname, style, status FROM ' . PREFIX . 'members ORDER BY LOWER(nickname);');
		while($temp=$result->fetch(PDO::FETCH_NUM)){
			$members[]=[htmlspecialchars($temp[0]), $temp[1], $temp[2]];
		}
		foreach($members as $member){
			echo "<option value=\"$member[0]\" style=\"$member[1]\">$member[0]";
			if($member[2]==0){
				echo ' (!)';
			}elseif($member[2]==2){
				echo ' (SG)';
			}elseif($member[2]==3){
			}elseif($member[2]==5){
				echo ' (M)';
			}elseif($member[2]==6){
				echo ' (SM)';
			}elseif($member[2]==7){
				echo ' (A)';
			}else{
				echo ' (SA)';
			}
			echo '</option>';
		}
		echo '</select><select name="set" size="1"><option value="">'._('(choose)').'</option><option value="-">'._('Delete from database').'</option><option value="0">'._('Deny access (!)').'</option>';
		if(get_setting('suguests')){
			echo '<option value="2">'._('Set to applicant (SG)').'</option>';
		}
		echo '<option value="3">'._('Set to regular member').'</option>';
		echo '<option value="5">'._('Set to moderator (M)').'</option>';
		echo '<option value="6">'._('Set to supermod (SM)').'</option>';
		if($U['status']>=8){
			echo '<option value="7">'._('Set to admin (A)').'</option>';
		}
		echo '</select></td><td>'.submit(_('Change')).'</td></tr></table></form></td></tr></table></td></tr>';
		thr();
		echo '<tr><td><table id="passreset"><tr><th>'._('Reset password').'</th><td>';
		echo form('admin', 'passreset');
		echo '<table><tr><td><select name="name" size="1"><option value="">'._('(choose)').'</option>';
		foreach($members as $member){
			echo "<option value=\"$member[0]\" style=\"$member[1]\">$member[0]</option>";
		}
		echo '</select></td><td><input type="password" name="pass" autocomplete="off"></td><td>'.submit(_('Change')).'</td></tr></table></form></td></tr></table></td></tr>';
		thr();
		echo '<tr><td><table id="register"><tr><th>'._('Register Guest').'</th><td>';
		echo form('admin', 'register');
		echo '<table><tr><td><select name="name" size="1"><option value="">'._('(choose)').'</option>';
		foreach($users as $user){
			if($user[2]==1){
				echo "<option value=\"$user[0]\" style=\"$user[1]\">$user[0]</option>";
			}
		}
		echo '</select></td><td>'.submit(_('Register')).'</td></tr></table></form></td></tr></table></td></tr>';
		thr();
		echo '<tr><td><table id="regnew"><tr><th>'._('Register new Member').'</th></tr><tr><td>';
		echo form('admin', 'regnew');
		echo '<table><tr><td>'._('Nickname:').'</td><td>&nbsp;</td><td><input type="text" name="name" size="20"></td><td>&nbsp;</td></tr>';
		echo '<tr><td>'._('Password:').'</td><td>&nbsp;</td><td><input type="password" name="pass" size="20" autocomplete="off"></td><td>';
		echo submit(_('Register')).'</td></tr></table></form></td></tr></table></td></tr>';
		thr();
	}
	echo "</table><br>";
	echo form('admin').submit(_('Reload')).'</form>';
	print_end();
}

function send_sessions(): void
{
	global $U, $db;
	$stmt=$db->prepare('SELECT nickname, style, lastpost, status, useragent, ip FROM ' . PREFIX . 'sessions WHERE entry!=0 AND (incognito=0 OR status<? OR nickname=?) ORDER BY status DESC, lastpost DESC;');
	$stmt->execute([$U['status'], $U['nickname']]);
	if(!$lines=$stmt->fetchAll(PDO::FETCH_ASSOC)){
		$lines=[];
	}
	print_start('sessions');
	echo '<h1>'._('Active Sessions').'</h1><table>';
	echo '<tr><th>'._('Nickname').'</th><th>'._('Timeout in').'</th><th>'._('User-Agent').'</th>';
	$trackip=(bool) get_setting('trackip');
	$memexpire=(int) get_setting('memberexpire');
	$guestexpire=(int) get_setting('guestexpire');
	if($trackip) echo '<th>'._('IP-Address').'</th>';
	echo '<th>'._('Actions').'</th></tr>';
	foreach($lines as $temp){
		if($temp['status']==0){
			$s=' (K)';
		}elseif($temp['status']<=1){
			$s=' (G)';
		}elseif($temp['status']==2){
			$s=' (SG)';
		}elseif($temp['status']==3){
			$s='';
		}elseif($temp['status']==5){
			$s=' (M)';
		}elseif($temp['status']==6){
			$s=' (SM)';
		}elseif($temp['status']==7){
			$s=' (A)';
		}else{
			$s=' (SA)';
		}
		echo '<tr><td class="nickname">'.style_this(htmlspecialchars($temp['nickname']).$s, $temp['style']).'</td><td class="timeout">';
		if($temp['status']>2){
			get_timeout((int) $temp['lastpost'], $memexpire);
		}else{
			get_timeout((int) $temp['lastpost'], $guestexpire);
		}
		echo '</td>';
		if($U['status']>$temp['status'] || $U['nickname']===$temp['nickname']){
			echo "<td class=\"ua\">$temp[useragent]</td>";
			if($trackip){
				echo "<td class=\"ip\">$temp[ip]</td>";
			}
			echo '<td class="action">';
			if($temp['nickname']!==$U['nickname']){
				echo '<table><tr>';
				if($temp['status']!=0){
					echo '<td>';
					echo form('admin', 'sessions');
					echo hidden('kick', '1').hidden('nick', htmlspecialchars($temp['nickname'])).submit(_('Kick')).'</form>';
					echo '</td>';
				}
				echo '<td>';
				echo form('admin', 'sessions');
				echo hidden('logout', '1').hidden('nick', htmlspecialchars($temp['nickname'])).submit($temp['status']==0 ? _('Unban') : _('Logout')).'</form>';
				echo '</td></tr></table>';
			}else{
				echo '-';
			}
			echo '</td></tr>';
		}else{
			echo '<td class="ua">-</td>';
			if($trackip){
				echo '<td class="ip">-</td>';
			}
			echo '<td class="action">-</td></tr>';
		}
	}
	echo "</table><br>";
	echo form('admin', 'sessions').submit(_('Reload')).'</form>';
	print_end();
}

function check_filter_match(int &$reg) : string {
	$_POST['match']=htmlspecialchars($_POST['match']);
	if(isset($_POST['regex']) && $_POST['regex']==1){
		if(!valid_regex($_POST['match'])){
			return _('Incorrect regular expression!').'<br>'.sprintf(_('Your match was as follows: %s'), htmlspecialchars($_POST['match']));
		}
		$reg=1;
	}else{
		$_POST['match']=preg_replace('/([^\w\d])/u', "\\\\$1", $_POST['match']);
		$reg=0;
	}
	if(mb_strlen($_POST['match'])>255){
		return _('Your match was too long. You can use max. 255 characters. Try splitting it up.')."<br>".sprintf(_('Your match was as follows: %s'), htmlspecialchars($_POST['match']));
	}
	return '';
}

function manage_filter() : string {
	global $db, $memcached;
	if(isset($_POST['id'])){
		$reg=0;
		if(($tmp=check_filter_match($reg)) !== ''){
			return $tmp;
		}
		if(isset($_POST['allowinpm']) && $_POST['allowinpm']==1){
			$pm=1;
		}else{
			$pm=0;
		}
		if(isset($_POST['kick']) && $_POST['kick']==1){
			$kick=1;
		}else{
			$kick=0;
		}
		if(isset($_POST['cs']) && $_POST['cs']==1){
			$cs=1;
		}else{
			$cs=0;
		}
		if(preg_match('/^[0-9]+$/', $_POST['id'])){
			if(empty($_POST['match'])){
				$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'filter WHERE id=?;');
				$stmt->execute([$_POST['id']]);
			}else{
				$stmt=$db->prepare('UPDATE ' . PREFIX . 'filter SET filtermatch=?, filterreplace=?, allowinpm=?, regex=?, kick=?, cs=? WHERE id=?;');
				$stmt->execute([$_POST['match'], $_POST['replace'], $pm, $reg, $kick, $cs, $_POST['id']]);
			}
		}elseif($_POST['id']==='+'){
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'filter (filtermatch, filterreplace, allowinpm, regex, kick, cs) VALUES (?, ?, ?, ?, ?, ?);');
			$stmt->execute([$_POST['match'], $_POST['replace'], $pm, $reg, $kick, $cs]);
		}
		if(MEMCACHED){
			$memcached->delete(DBNAME . '-' . PREFIX . 'filter');
		}
	}
	return '';
}

function manage_linkfilter() : string {
	global $db, $memcached;
	if(isset($_POST['id'])){
		$reg=0;
		if(($tmp=check_filter_match($reg)) !== ''){
			return $tmp;
		}
		if(preg_match('/^[0-9]+$/', $_POST['id'])){
			if(empty($_POST['match'])){
				$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'linkfilter WHERE id=?;');
				$stmt->execute([$_POST['id']]);
			}else{
				$stmt=$db->prepare('UPDATE ' . PREFIX . 'linkfilter SET filtermatch=?, filterreplace=?, regex=? WHERE id=?;');
				$stmt->execute([$_POST['match'], $_POST['replace'], $reg, $_POST['id']]);
			}
		}elseif($_POST['id']==='+'){
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'linkfilter (filtermatch, filterreplace, regex) VALUES (?, ?, ?);');
			$stmt->execute([$_POST['match'], $_POST['replace'], $reg]);
		}
		if(MEMCACHED){
			$memcached->delete(DBNAME . '-' . PREFIX . 'linkfilter');
		}
	}
	return '';
}

function get_filters() : array {
	global $db, $memcached;
	$filters=[];
	if(MEMCACHED){
		$filters=$memcached->get(DBNAME . '-' . PREFIX . 'filter');
	}
	if(!MEMCACHED || $memcached->getResultCode()!==Memcached::RES_SUCCESS){
		$filters=[];
		$result=$db->query('SELECT id, filtermatch, filterreplace, allowinpm, regex, kick, cs FROM ' . PREFIX . 'filter;');
		while($filter=$result->fetch(PDO::FETCH_ASSOC)){
			$filters[]=['id'=>$filter['id'], 'match'=>$filter['filtermatch'], 'replace'=>$filter['filterreplace'], 'allowinpm'=>$filter['allowinpm'], 'regex'=>$filter['regex'], 'kick'=>$filter['kick'], 'cs'=>$filter['cs']];
		}
		if(MEMCACHED){
			$memcached->set(DBNAME . '-' . PREFIX . 'filter', $filters);
		}
	}
	return $filters;
}

function get_linkfilters() : array {
	global $db, $memcached;
	$filters=[];
	if(MEMCACHED){
		$filters=$memcached->get(DBNAME . '-' . PREFIX . 'linkfilter');
	}
	if(!MEMCACHED || $memcached->getResultCode()!==Memcached::RES_SUCCESS){
		$filters=[];
		$result=$db->query('SELECT id, filtermatch, filterreplace, regex FROM ' . PREFIX . 'linkfilter;');
		while($filter=$result->fetch(PDO::FETCH_ASSOC)){
			$filters[]=['id'=>$filter['id'], 'match'=>$filter['filtermatch'], 'replace'=>$filter['filterreplace'], 'regex'=>$filter['regex']];
		}
		if(MEMCACHED){
			$memcached->set(DBNAME . '-' . PREFIX . 'linkfilter', $filters);
		}
	}
	return $filters;
}

function send_filter(string $arg=''): void
{
	global $U;
	print_start('filter');
	echo '<h2>'._('Filter')."</h2><i>$arg</i><table>";
	thr();
	echo '<tr><th><table><tr>';
	echo '<td>'._('Filter ID:').'</td>';
	echo '<td>'._('Match').'</td>';
	echo '<td>'._('Replace').'</td>';
	echo '<td>'._('Allow in PM').'</td>';
	echo '<td>'._('Regex').'</td>';
	echo '<td>'._('Kick').'</td>';
	echo '<td>'._('Case sensitive').'</td>';
	echo '<td>'._('Apply').'</td>';
	echo '</tr></table></th></tr>';
	$filters=get_filters();
	foreach($filters as $filter){
		if($filter['allowinpm']==1){
			$check=' checked';
		}else{
			$check='';
		}
		if($filter['regex']==1){
			$checked=' checked';
		}else{
			$checked='';
			$filter['match']=preg_replace('/(\\\\(.))/u', "$2", $filter['match']);
		}
		if($filter['kick']==1){
			$checkedk=' checked';
		}else{
			$checkedk='';
		}
		if($filter['cs']==1){
			$checkedcs=' checked';
		}else{
			$checkedcs='';
		}
		echo '<tr><td>';
		echo form('admin', 'filter').hidden('id', $filter['id']);
		echo '<table><tr><td>'._('Filter')." $filter[id]:</td>";
		echo '<td><input type="text" name="match" value="'.$filter['match'].'" size="20" style="'.$U['style'].'"></td>';
		echo '<td><input type="text" name="replace" value="'.htmlspecialchars($filter['replace']).'" size="20" style="'.$U['style'].'"></td>';
		echo '<td><label><input type="checkbox" name="allowinpm" value="1"'.$check.'>'._('Allow in PM').'</label></td>';
		echo '<td><label><input type="checkbox" name="regex" value="1"'.$checked.'>'._('Regex').'</label></td>';
		echo '<td><label><input type="checkbox" name="kick" value="1"'.$checkedk.'>'._('Kick').'</label></td>';
		echo '<td><label><input type="checkbox" name="cs" value="1"'.$checkedcs.'>'._('Case sensitive').'</label></td>';
		echo '<td class="filtersubmit">'.submit(_('Change')).'</td></tr></table></form></td></tr>';
	}
	echo '<tr><td>';
	echo form('admin', 'filter').hidden('id', '+');
	echo '<table><tr><td>'._('New filter:').'</td>';
	echo '<td><input type="text" name="match" value="" size="20" style="'.$U['style'].'"></td>';
	echo '<td><input type="text" name="replace" value="" size="20" style="'.$U['style'].'"></td>';
	echo '<td><label><input type="checkbox" name="allowinpm" id="allowinpm" value="1">'._('Allow in PM').'</label></td>';
	echo '<td><label><input type="checkbox" name="regex" id="regex" value="1">'._('Regex').'</label></td>';
	echo '<td><label><input type="checkbox" name="kick" id="kick" value="1">'._('Kick').'</label></td>';
	echo '<td><label><input type="checkbox" name="cs" id="cs" value="1">'._('Case sensitive').'</label></td>';
	echo '<td class="filtersubmit">'.submit(_('Add')).'</td></tr></table></form></td></tr>';
	echo '</table><br>';
	echo form('admin', 'filter').submit(_('Reload')).'</form>';
	print_end();
}

function send_linkfilter(string $arg=''): void
{
	global $U;
	print_start('linkfilter');
	echo '<h2>'._('Linkfilter')."</h2><i>$arg</i><table>";
	thr();
	echo '<tr><th><table><tr>';
	echo '<td>'._('Filter ID:').'</td>';
	echo '<td>'._('Match').'</td>';
	echo '<td>'._('Replace').'</td>';
	echo '<td>'._('Regex').'</td>';
	echo '<td>'._('Apply').'</td>';
	echo '</tr></table></th></tr>';
	$filters=get_linkfilters();
	foreach($filters as $filter){
		if($filter['regex']==1){
			$checked=' checked';
		}else{
			$checked='';
			$filter['match']=preg_replace('/(\\\\(.))/u', "$2", $filter['match']);
		}
		echo '<tr><td>';
		echo form('admin', 'linkfilter').hidden('id', $filter['id']);
		echo '<table><tr><td>'._('Filter')." $filter[id]:</td>";
		echo '<td><input type="text" name="match" value="'.$filter['match'].'" size="20" style="'.$U['style'].'"></td>';
		echo '<td><input type="text" name="replace" value="'.htmlspecialchars($filter['replace']).'" size="20" style="'-$U['style'].'"></td>';
		echo '<td><label><input type="checkbox" name="regex" value="1"'.$checked.'>'._('Regex').'</label></td>';
		echo '<td class="filtersubmit">'.submit(_('Change')).'</td></tr></table></form></td></tr>';
	}
	echo '<tr><td>';
	echo form('admin', 'linkfilter').hidden('id', '+');
	echo '<table><tr><td>'._('New filter:').'</td>';
	echo '<td><input type="text" name="match" value="" size="20" style="'.$U['style'].'"></td>';
	echo '<td><input type="text" name="replace" value="" size="20" style="'.$U['style'].'"></td>';
	echo '<td><label><input type="checkbox" name="regex" value="1">'._('Regex').'</label></td>';
	echo '<td class="filtersubmit">'.submit(_('Add')).'</td></tr></table></form></td></tr>';
	echo '</table><br>';
	echo form('admin', 'linkfilter').submit(_('Reload')).'</form>';
	print_end();
}

function send_frameset(): void
{
	global $U, $db, $language, $dir;
	prepare_stylesheets('frameset');
	send_headers();
	echo '<!DOCTYPE html><html lang="'.$language.'" dir="'.$dir.'"><head>'.meta_html();
	echo '<title>'.get_setting('chatname').'</title>';
	print_stylesheet('frameset');
	echo '</head><body>';
	if(isset($_POST['sort'])){
		if($_POST['sort']==1){
			$U['sortupdown']=1;
		}else{
			$U['sortupdown']=0;
		}
		$tmp=$U['nocache'];
		$U['nocache']=$U['nocache_old'];
		$U['nocache_old']=$tmp;
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET sortupdown=?, nocache=?, nocache_old=? WHERE nickname=?;');
		$stmt->execute([$U['sortupdown'], $U['nocache'], $U['nocache_old'], $U['nickname']]);
		if($U['status']>1){
			$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET sortupdown=?, nocache=?, nocache_old=? WHERE nickname=?;');
			$stmt->execute([$U['sortupdown'], $U['nocache'], $U['nocache_old'], $U['nickname']]);
		}
	}
	$bottom='';
	if(get_setting('enablegreeting')){
		$action_mid='greeting';
	} else {
		if($U['sortupdown']){
			$bottom='#bottom';
		}
		$action_mid='view';
	}
	if((!isset($_REQUEST['sort']) && !$U['sortupdown']) || (isset($_REQUEST['sort']) && $_REQUEST['sort']==0)){
		$action_top='post';
		$action_bot='controls';
		$sort_bot='&sort=1';
	}else{
		$action_top='controls';
		$action_bot='post';
		$sort_bot='';
		}
	echo "<div id=\"frameset-mid\"><iframe name=\"view\" src=\"$_SERVER[SCRIPT_NAME]?action=$action_mid&session=$U[session]&lang=$language$bottom\">".noframe_html()."</iframe></div>";
	echo "<div id=\"frameset-top\"><iframe name=\"$action_top\" src=\"$_SERVER[SCRIPT_NAME]?action=$action_top&session=$U[session]&lang=$language\">".noframe_html()."</iframe></div>";
	echo "<div id=\"frameset-bot\"><iframe name=\"$action_bot\" src=\"$_SERVER[SCRIPT_NAME]?action=$action_bot&session=$U[session]&lang=$language$sort_bot\">".noframe_html()."</iframe></div>";
	echo '</body></html>';
	exit;
}

function noframe_html() : string {
	return _('This chat uses <b>frames</b>. Please enable frames in your browser or use a suitable one!').form_target('_parent', '').submit(_('Back to the login page.'), 'class="backbutton"').'</form>';
}

function send_messages(): void
{
	global $U, $language;
	if($U['nocache']){
		$nocache='&nc='.substr(time(), -6);
	}else{
		$nocache='';
	}
	if($U['sortupdown']){
		$sort='#bottom';
	}else{
		$sort='';
	}
	print_start('messages', (int) $U['refresh'], "$_SERVER[SCRIPT_NAME]?action=view&session=$U[session]&lang=$language$nocache$sort");
	echo '<a id="top"></a>';
	echo '<a id="bottom_link" href="#bottom">'._('Bottom').'</a>';
	echo '<div id="manualrefresh"><br>'._('Manual refresh required').'<br>'.form('view').submit(_('Reload')).'</form><br></div>';
	if(!$U['sortupdown']){
		echo '<div id="topic">';
		echo get_setting('topic');
		echo '</div>';
		print_chatters();
		print_notifications();
		print_messages();
	}else{
		print_messages();
		print_notifications();
		print_chatters();
		echo '<div id="topic">';
		echo get_setting('topic');
		echo '</div>';
	}
	echo '<a id="bottom"></a><a id="top_link" href="#top">'._('Top').'</a>';
	print_end();
}

function send_inbox(): void
{
	global $U, $db;
	print_start('inbox');
	echo form('inbox', 'clean').submit(_('Delete selected messages'), 'class="delbutton"').'<br><br>';
	$dateformat=get_setting('dateformat');
	if(!$U['embed'] && get_setting('imgembed')){
		$removeEmbed=true;
	}else{
		$removeEmbed=false;
	}
	if($U['timestamps'] && !empty($dateformat)){
		$timestamps=true;
	}else{
		$timestamps=false;
	}
	if($U['sortupdown']){
		$direction='ASC';
	}else{
		$direction='DESC';
	}
	$stmt=$db->prepare('SELECT id, postdate, text FROM ' . PREFIX . "inbox WHERE recipient=? ORDER BY id $direction;");
	$stmt->execute([$U['nickname']]);
	while($message=$stmt->fetch(PDO::FETCH_ASSOC)){
		prepare_message_print($message, $removeEmbed);
		echo "<div class=\"msg\"><label><input type=\"checkbox\" name=\"mid[]\" value=\"$message[id]\">";
		if($timestamps){
			echo ' <small>'.date($dateformat, $message['postdate']).' - </small>';
		}
		echo " $message[text]</label></div>";
	}
	echo '</form><br>'.form('view').submit(_('Back to the chat.'), 'class="backbutton"').'</form>';
	print_end();
}

function send_notes(int $type): void
{
	global $U, $db;
	print_start('notes');
	$personalnotes=(bool) get_setting('personalnotes');
	$publicnotes=(bool) get_setting('publicnotes');
	if($U['status']>=3 && ($personalnotes || $publicnotes)){
		echo '<table><tr>';
		if($U['status']>6){
			echo '<td>'.form_target('view', 'notes', 'admin').submit(_('Admin notes')).'</form></td>';
		}
		if($U['status']>=5){
			echo '<td>'.form_target('view', 'notes', 'staff').submit(_('Staff notes')).'</form></td>';
		}
		if($personalnotes){
			echo '<td>'.form_target('view', 'notes').submit(_('Personal notes')).'</form></td>';
		}
		if($publicnotes){
			echo '<td>'.form_target('view', 'notes', 'public').submit(_('Public notes')).'</form></td>';
		}
		echo '</tr></table>';
	}
	if($type===1){
		echo '<h2>'._('Staff notes').'</h2><p>';
		$hiddendo=hidden('do', 'staff');
	}elseif($type===0){
		echo '<h2>'._('Admin notes').'</h2><p>';
		$hiddendo=hidden('do', 'admin');
	}elseif($type===2){
		echo '<h2>'._('Personal notes').'</h2><p>';
		$hiddendo='';
	}elseif($type===3){
		echo '<h2>'._('Public notes').'</h2><p>';
		$hiddendo=hidden('do', 'public');
	}
	if(isset($_POST['text'])){
		if(MSGENCRYPTED){
			try {
				$_POST['text']=base64_encode(sodium_crypto_aead_aes256gcm_encrypt($_POST['text'], '', AES_IV, ENCRYPTKEY));
			} catch (SodiumException $e){
				send_error($e->getMessage());
			}
		}
		$time=time();
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'notes (type, lastedited, editedby, text) VALUES (?, ?, ?, ?);');
		$stmt->execute([$type, $time, $U['nickname'], $_POST['text']]);
		echo '<b>'._('Notes saved!').'</b> ';
	}
	$dateformat=get_setting('dateformat');
	if(($type!==2) && ($type !==3)){
		$stmt=$db->prepare('SELECT COUNT(*) FROM ' . PREFIX . 'notes WHERE type=?;');
		$stmt->execute([$type]);
	}else{
		$stmt=$db->prepare('SELECT COUNT(*) FROM ' . PREFIX . 'notes WHERE type=? AND editedby=?;');
		$stmt->execute([$type, $U['nickname']]);
	}
	$num=$stmt->fetch(PDO::FETCH_NUM);
	if(!empty($_POST['revision'])){
		$revision=intval($_POST['revision']);
	}else{
		$revision=0;
	}
	if(($type!==2) && ($type !==3)){
		$stmt=$db->prepare('SELECT * FROM ' . PREFIX . "notes WHERE type=? ORDER BY id DESC LIMIT 1 OFFSET $revision;");
		$stmt->execute([$type]);
	}else{
		$stmt=$db->prepare('SELECT * FROM ' . PREFIX . "notes WHERE type=? AND editedby=? ORDER BY id DESC LIMIT 1 OFFSET $revision;");
		$stmt->execute([$type, $U['nickname']]);
	}
	if($note=$stmt->fetch(PDO::FETCH_ASSOC)){
		printf(_('Last edited by %1$s at %2$s'), htmlspecialchars($note['editedby']), date($dateformat, $note['lastedited']));
	}else{
		$note['text']='';
	}
	if(MSGENCRYPTED){
		try {
			$note['text']=sodium_crypto_aead_aes256gcm_decrypt(base64_decode($note['text']), null, AES_IV, ENCRYPTKEY);
		} catch (SodiumException $e){
			send_error($e->getMessage());
		}
	}
	echo "</p>".form('notes');
	echo "$hiddendo<textarea name=\"text\">".htmlspecialchars($note['text']).'</textarea><br>';
	echo submit(_('Save notes')).'</form><br>';
	if($num[0]>1){
		echo '<br><table><tr><td>'._('Revisions:').'</td>';
		if($revision<$num[0]-1){
			echo '<td>'.form('notes').hidden('revision', $revision+1);
			echo $hiddendo.submit(_('Older')).'</form></td>';
		}
		if($revision>0){
			echo '<td>'.form('notes').hidden('revision', $revision-1);
			echo $hiddendo.submit(_('Newer')).'</form></td>';
		}
		echo '</tr></table>';
	}
	print_end();
}

function send_approve_waiting(): void
{
	global $db;
	print_start('approve_waiting');
	echo '<h2>'._('Waiting room').'</h2>';
	$result=$db->query('SELECT * FROM ' . PREFIX . 'sessions WHERE entry=0 AND status=1 ORDER BY id LIMIT 100;');
	if($tmp=$result->fetchAll(PDO::FETCH_ASSOC)){
		echo form('admin', 'approve');
		echo '<table>';
		echo '<tr><th>'._('Nickname').'</th><th>'._('User-Agent').'</th></tr>';
		foreach($tmp as $temp){
			echo '<tr>'.hidden('alls[]', htmlspecialchars($temp['nickname']));
			echo '<td><label><input type="checkbox" name="csid[]" value="'.htmlspecialchars($temp['nickname']).'">';
			echo style_this(htmlspecialchars($temp['nickname']), $temp['style']).'</label></td>';
			echo "<td>$temp[useragent]</td></tr>";
		}
		echo '</table><br><table id="action"><tr><td><label><input type="radio" name="what" value="allowchecked" id="allowchecked" checked>'._('Allow checked').'</label></td>';
		echo '<td><label><input type="radio" name="what" value="allowall" id="allowall">'._('Allow all').'</label></td>';
		echo '<td><label><input type="radio" name="what" value="denychecked" id="denychecked">'._('Deny checked').'</label></td>';
		echo '<td><label><input type="radio" name="what" value="denyall" id="denyall">'._('Deny all').'</label></td></tr><tr><td colspan="8">'._('Send message to denied:').' <input type="text" name="kickmessage" size="45"></td>';
		echo '</tr><tr><td colspan="8">'.submit(_('Submit')).'</td></tr></table></form>';
	}else{
		echo _('No more entry requests to approve.').'<br>';
	}
	echo '<br>'.form('view').submit(_('Back to the chat.'), 'class="backbutton"').'</form>';
	print_end();
}

function send_waiting_room(): void
{
	global $U, $db, $language;
	$ga=(int) get_setting('guestaccess');
	if($ga===3 && (get_count_mods()>0 || !get_setting('modfallback'))){
		$wait=false;
	}else{
		$wait=true;
	}
	check_expired();
	check_kicked();
	$timeleft=get_setting('entrywait')-(time()-$U['lastpost']);
	if($wait && ($timeleft<=0 || $ga===1)){
		$U['entry']=$U['lastpost'];
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET entry=lastpost WHERE session=?;');
		$stmt->execute([$U['session']]);
		send_frameset();
	}elseif(!$wait && $U['entry']!=0){
		send_frameset();
	}else{
		$refresh=(int) get_setting('defaultrefresh');
		print_start('waitingroom', $refresh, "$_SERVER[SCRIPT_NAME]?action=wait&session=$U[session]&lang=$language&nc=".substr(time(),-6));
		echo '<h2>'._('Waiting room').'</h2><p>';
		if($wait){
			printf(_('Welcome %1$s, your login has been delayed, you can access the chat in %2$d seconds.'), style_this(htmlspecialchars($U['nickname']), $U['style']), $timeleft);
		}else{
			printf(_('Welcome %1$s, your login has been delayed, you can access the chat as soon, as a moderator lets you in.'), style_this(htmlspecialchars($U['nickname']), $U['style']));
		}
		echo '</p><br><p>';
		printf(_("If this page doesn't refresh every %d seconds, use the button below to reload it manually!"), $refresh);
		echo '</p><br><br>';
		echo '<hr>'.form('wait');
		echo submit(_('Reload')).'</form><br>';
		echo form('logout');
		echo submit(_('Exit Chat'), 'id="exitbutton"').'</form>';
		$rulestxt=get_setting('rulestxt');
		if(!empty($rulestxt)){
			echo '<div id="rules"><h2>'._('Rules')."</h2><b>$rulestxt</b></div>";
		}
		print_end();
	}
}

function send_choose_messages(): void
{
	global $U;
	print_start('choose_messages');
	echo form('admin', 'clean');
	echo hidden('what', 'selected').submit(_('Delete selected messages'), 'class="delbutton"').'<br><br>';
	print_messages((int) $U['status']);
	echo '<br>'.submit(_('Delete selected messages'), 'class="delbutton"')."</form>";
	print_end();
}

function send_del_confirm(): void
{
	print_start('del_confirm');
	echo '<table><tr><td colspan="2">'._('Are you sure?').'</td></tr><tr><td>'.form('delete');
	if(isset($_POST['multi'])){
		echo hidden('multi', 'on');
	}
	if(isset($_POST['sendto'])){
		echo hidden('sendto', $_POST['sendto']);
	}
	echo hidden('confirm', 'yes').hidden('what', $_POST['what']).submit(_('Yes'), 'class="delbutton"').'</form></td><td>'.form('post');
	if(isset($_POST['multi'])){
		echo hidden('multi', 'on');
	}
	if(isset($_POST['sendto'])){
		echo hidden('sendto', $_POST['sendto']);
	}
	echo submit(_('No'), 'class="backbutton"').'</form></td><tr></table>';
	print_end();
}

function send_post(string $rejected=''): void
{
	global $U, $db;
	print_start('post');
	if(!isset($_REQUEST['sendto'])){
		$_REQUEST['sendto']='';
	}
	echo '<table><tr><td>'.form('post');
	echo hidden('postid', $U['postid']);
	if(isset($_POST['multi'])){
		echo hidden('multi', 'on');
	}
	echo '<table><tr><td><table><tr id="firstline"><td>'.style_this(htmlspecialchars($U['nickname']), $U['style']).'</td><td>:</td>';
	if(isset($_POST['multi'])){
		echo "<td><textarea name=\"message\" rows=\"3\" cols=\"40\" style=\"$U[style]\" autofocus>$rejected</textarea></td>";
	}else{
		echo "<td><input type=\"text\" name=\"message\" value=\"$rejected\" size=\"40\" style=\"$U[style]\" autofocus></td>";
	}
	echo '<td>'.submit(_('Send to')).'</td><td><select name="sendto" size="1">';
	echo '<option ';
	if($_REQUEST['sendto']==='s *'){
		echo 'selected ';
	}
	echo 'value="s *">-'._('All chatters').'-</option>';
	if($U['status']>=3){
		echo '<option ';
		if($_REQUEST['sendto']==='s ?'){
			echo 'selected ';
		}
		echo 'value="s ?">-'._('Members only').'-</option>';
	}
	if($U['status']>=5){
		echo '<option ';
		if($_REQUEST['sendto']==='s %'){
			echo 'selected ';
		}
		echo 'value="s %">-'._('Staff only').'-</option>';
	}
	if($U['status']>=6){
		echo '<option ';
		if($_REQUEST['sendto']==='s _'){
			echo 'selected ';
		}
		echo 'value="s _">-'._('Admin only').'-</option>';
	}
	$disablepm=(bool) get_setting('disablepm');
	if(!$disablepm){
		$users=[];
		$stmt=$db->prepare('SELECT * FROM (SELECT nickname, style, 0 AS offline FROM ' . PREFIX . 'sessions WHERE entry!=0 AND status>0 AND incognito=0 UNION SELECT nickname, style, 1 AS offline FROM ' . PREFIX . 'members WHERE eninbox!=0 AND eninbox<=? AND nickname NOT IN (SELECT nickname FROM ' . PREFIX . 'sessions WHERE incognito=0)) AS t WHERE nickname NOT IN (SELECT ign FROM '. PREFIX . 'ignored WHERE ignby=? UNION SELECT ignby FROM '. PREFIX . 'ignored WHERE ign=?) ORDER BY LOWER(nickname);');
		$stmt->execute([$U['status'], $U['nickname'], $U['nickname']]);
		while($tmp=$stmt->fetch(PDO::FETCH_ASSOC)){
			if($tmp['offline']){
				$users[]=["$tmp[nickname] "._('(offline)'), $tmp['style'], $tmp['nickname']];
			}else{
				$users[]=[$tmp['nickname'], $tmp['style'], $tmp['nickname']];
			}
		}
		foreach($users as $user){
			if($U['nickname']!==$user[2]){
				echo '<option ';
				if($_REQUEST['sendto']==$user[2]){
					echo 'selected ';
				}
				echo 'value="'.htmlspecialchars($user[2])."\" style=\"$user[1]\">".htmlspecialchars($user[0]).'</option>';
			}
		}
	}
	echo '</select></td>';
	if(get_setting('enfileupload')>0 && get_setting('enfileupload')<=$U['status']){
		if(!$disablepm && ($U['status']>=5 || ($U['status']>=3 && (get_setting('memkickalways') || (get_count_mods()==0 && get_setting('memkick')))))){
			echo '</tr></table><table><tr id="secondline">';
		}
		printf('<td><input type="file" name="file"><small>'.('Max %d KB').'</small></td>', get_setting('maxuploadsize'));
	}
	if(!$disablepm && ($U['status']>=5 || ($U['status']>=3 && (get_setting('memkickalways') || (get_count_mods()==0 && get_setting('memkick')))))){
		echo '<td><label><input type="checkbox" name="kick" id="kick" value="kick">'._('Kick').'</label></td>';
		echo '<td><label><input type="checkbox" name="what" id="what" value="purge" checked>'._('Also purge messages').'</label></td>';
	}
	echo '</tr></table></td></tr></table></form></td></tr><tr><td><table><tr id="thirdline"><td>'.form('delete');
	if(isset($_POST['multi'])){
		echo hidden('multi', 'on');
	}
	echo hidden('sendto', htmlspecialchars($_REQUEST['sendto'])).hidden('what', 'last');
	echo submit(_('Delete last message'), 'class="delbutton"').'</form></td><td>'.form('delete');
	if(isset($_POST['multi'])){
		echo hidden('multi', 'on');
	}
	echo hidden('sendto', htmlspecialchars($_REQUEST['sendto'])).hidden('what', 'all');
	echo submit(_('Delete all messages'), 'class="delbutton"').'</form></td><td class="spacer"></td><td>'.form('post');
	if(isset($_POST['multi'])){
		echo submit(_('Switch to single-line'));
	}else{
		echo hidden('multi', 'on').submit(_('Switch to multi-line'));
	}
	echo hidden('sendto', htmlspecialchars($_REQUEST['sendto'])).'</form></td>';
	echo '</tr></table></td></tr></table>';
	print_end();
}

function send_greeting(): void
{
	global $U, $language;
	print_start('greeting', (int) $U['refresh'], "$_SERVER[SCRIPT_NAME]?action=view&session=$U[session]&lang=$language");
	printf('<h1>'._('Welcome %s!').'</h1>', style_this(htmlspecialchars($U['nickname']), $U['style']));
	printf('<hr><small>'._('If this frame does not reload in %d seconds, you\'ll have to enable automatic redirection (meta refresh) in your browser. Also make sure no web filter, local proxy tool or browser plugin is preventing automatic refreshing! This could be for example "Polipo", "NoScript", etc.<br>As a workaround (or in case of server/proxy reload errors) you can always use the buttons at the bottom to refresh manually.').'</small>', $U['refresh']);
	$rulestxt=get_setting('rulestxt');
	if(!empty($rulestxt)){
		echo '<hr><div id="rules"><h2>'._('Rules')."</h2>$rulestxt</div>";
	}
	print_end();
}

function send_help(): void
{
	global $U;
	print_start('help');
	$rulestxt=get_setting('rulestxt');
	if(!empty($rulestxt)){
		echo '<div id="rules"><h2>'._('Rules')."</h2>$rulestxt<br></div><hr>";
	}
	echo '<h2>'._('Help').'</h2>';
	echo _("All functions should be pretty much self-explaining, just use the buttons. In your profile you can adjust the refresh rate and font colour, as well as ignore users.<br><u>Note:</u> This is a chat, so if you don't keep talking, you will be automatically logged out after a while.");
	if(get_setting('imgembed')){
		echo '<br>'._('If you want to embed an image in your post, simply put [img] in front of your image URL. Example: [img]http://example.com/images/file.jpg will embed the image in your post.');
	}
	if($U['status']>=3){
		echo '<br>'._("Members: You'll have some more options in your profile. You can adjust your font face, change your password anytime and of course you can delete your account.").'<br>';
		if($U['status']>=5){
			echo '<br>'._("Moderators: Notice the Admin-button at the bottom. It'll bring up a page where you can clean the room, kick chatters, view all active sessions and disable guest access completely if needed.").'<br>';
			if($U['status']>=7){
				echo '<br>'._("Admins: You'll be furthermore able to register guests, edit members and register new nicknames.").'<br>';
			}
		}
	}
	echo '<br><hr><div id="backcredit">'.form('view').submit(_('Back to the chat.'), 'class="backbutton"').'</form>'.credit().'</div>';
	print_end();
}

function view_publicnotes(): void
{
	global $db;
	$dateformat = get_setting('dateformat');
	print_start('publicnotes');
	echo '<h2>'._('Public notes').'</h2><p>';
	$query = $db->query('SELECT lastedited, editedby, text FROM ' . PREFIX . 'notes INNER JOIN (SELECT MAX(id) AS latest FROM ' . PREFIX . 'notes WHERE type=3 GROUP BY editedby) AS t ON t.latest = id;');
	while($result = $query->fetch(PDO::FETCH_OBJ)){
		if (!empty($result->text)) {
			if(MSGENCRYPTED){
				try {
					$result->text = sodium_crypto_aead_aes256gcm_decrypt(base64_decode($result->text), null, AES_IV, ENCRYPTKEY);
				} catch (SodiumException $e){
					send_error($e->getMessage());
				}
			}
			echo '<hr>';
			printf(_('Last edited by %1$s at %2$s'), htmlspecialchars($result->editedby), date($dateformat, $result->lastedited));
			echo '<br>';
			echo '<textarea cols="80" rows="9" readonly="true">' . htmlspecialchars($result->text) . '</textarea>';
			echo '<br>';
		}
	}
	print_end();
}

function send_profile(string $arg=''): void
{
	global $U, $db, $language;
	print_start('profile');
	echo form('profile', 'save').'<h2>'._('Your Profile')."</h2><i>$arg</i><table>";
	thr();
	$ignored=[];
	$stmt=$db->prepare('SELECT ign FROM ' . PREFIX . 'ignored WHERE ignby=? ORDER BY LOWER(ign);');
	$stmt->execute([$U['nickname']]);
	while($tmp=$stmt->fetch(PDO::FETCH_ASSOC)){
		$ignored[]=htmlspecialchars($tmp['ign']);
	}
	if(count($ignored)>0){
		echo '<tr><td><table id="unignore"><tr><th>'._("Don't ignore anymore").'</th><td>';
		echo '<select name="unignore" size="1"><option value="">'._('(choose)').'</option>';
		foreach($ignored as $ign){
			echo "<option value=\"$ign\">$ign</option>";
		}
		echo '</select></td></tr></table></td></tr>';
		thr();
	}
	echo '<tr><td><table id="ignore"><tr><th>'._('Ignore').'</th><td>';
	echo '<select name="ignore" size="1"><option value="">'._('(choose)').'</option>';
	$stmt=$db->prepare('SELECT DISTINCT poster, style FROM ' . PREFIX . 'messages INNER JOIN (SELECT nickname, style FROM ' . PREFIX . 'sessions UNION SELECT nickname, style FROM ' . PREFIX . 'members) AS t ON (' . PREFIX . 'messages.poster=t.nickname) WHERE poster!=? AND poster NOT IN (SELECT ign FROM ' . PREFIX . 'ignored WHERE ignby=?) ORDER BY LOWER(poster);');
	$stmt->execute([$U['nickname'], $U['nickname']]);
	while($nick=$stmt->fetch(PDO::FETCH_NUM)){
		echo '<option value="'.htmlspecialchars($nick[0])."\" style=\"$nick[1]\">".htmlspecialchars($nick[0]).'</option>';
	}
	echo '</select></td></tr></table></td></tr>';
	thr();
	$max_refresh_rate = get_setting('max_refresh_rate');
	$min_refresh_rate = get_setting('min_refresh_rate');
	echo '<tr><td><table id="refresh"><tr><th>'.sprintf(_('Refresh rate (%1$d-%2$d seconds)'), $min_refresh_rate, $max_refresh_rate).'</th><td>';
	echo '<input type="number" name="refresh" size="3" min="'.$min_refresh_rate.'" max="'.$max_refresh_rate.'" value="'.$U['refresh'].'"></td></tr></table></td></tr>';
	thr();
	preg_match('/#([0-9a-f]{6})/i', $U['style'], $matches);
	echo '<tr><td><table id="colour"><tr><th>'._('Font colour')." (<a href=\"$_SERVER[SCRIPT_NAME]?action=colours&amp;session=$U[session]&amp;lang=$language\" target=\"view\">"._('View examples').'</a>)</th><td>';
	echo "<input type=\"color\" value=\"#$matches[1]\" name=\"colour\"></td></tr></table></td></tr>";
	thr();
	echo '<tr><td><table id="bgcolour"><tr><th>'._('Background colour')." (<a href=\"$_SERVER[SCRIPT_NAME]?action=colours&amp;session=$U[session]&amp;lang=$language\" target=\"view\">"._('View examples').'</a>)</th><td>';
	echo "<input type=\"color\" value=\"#$U[bgcolour]\" name=\"bgcolour\"></td></tr></table></td></tr>";
	thr();
	if($U['status']>=3){
		echo '<tr><td><table id="font"><tr><th>'._('Fontface').'</th><td><table>';
		echo '<tr><td>&nbsp;</td><td><select name="font" size="1"><option value="">* '._('Room Default').' *</option>';
		$F=load_fonts();
		foreach($F as $name=>$font){
			echo "<option style=\"$font\" ";
			if(strpos($U['style'], $font)!==false){
				echo 'selected ';
			}
			echo "value=\"$name\">$name</option>";
		}
		echo '</select></td><td>&nbsp;</td><td><label><input type="checkbox" name="bold" id="bold" value="on"';
		if(strpos($U['style'], 'font-weight:bold;')!==false){
			echo ' checked';
		}
		echo '><b>'._('Bold').'</b></label></td><td>&nbsp;</td><td><label><input type="checkbox" name="italic" id="italic" value="on"';
		if(strpos($U['style'], 'font-style:italic;')!==false){
			echo ' checked';
		}
		echo '><i>'._('Italic').'</i></label></td><td>&nbsp;</td><td><label><input type="checkbox" name="small" id="small" value="on"';
		if(strpos($U['style'], 'font-size:smaller;')!==false){
			echo ' checked';
		}
		echo '><small>'._('Small').'</small></label></td></tr></table></td></tr></table></td></tr>';
		thr();
	}
	echo '<tr><td>'.style_this(htmlspecialchars($U['nickname'])." : "._('Example for your chosen font'), $U['style']).'</td></tr>';
	thr();
	$bool_settings=[
		'timestamps' => _('Show Timestamps'),
		'nocache' => _('Autoscroll (for old browsers or top-to-bottom sort).'),
		'sortupdown' => _('Sort messages from top to bottom'),
		'hidechatters' => _('Hide list of chatters'),
	];
	if(get_setting('imgembed')){
		$bool_settings[]='embed';
	}
	if($U['status']>=5 && get_setting('incognito')){
		$bool_settings[]='incognito';
	}
	foreach($bool_settings as $setting => $title){
		echo "<tr><td><table id=\"$setting\"><tr><th>".$title.'</th><td>';
		echo "<label><input type=\"checkbox\" name=\"$setting\" value=\"on\"";
		if($U[$setting]){
			echo ' checked';
		}
		echo '><b>'._('Enabled').'</b></label></td></tr></table></td></tr>';
		thr();
	}
	if($U['status']>=2 && get_setting('eninbox')){
		echo '<tr><td><table id="eninbox"><tr><th>'._('Enable offline inbox').'</th><td>';
		echo '<select name="eninbox" id="eninbox">';
		echo '<option value="0"';
		if($U['eninbox']==0){
			echo ' selected';
		}
		echo '>'._('Disabled').'</option>';
		echo '<option value="1"';
		if($U['eninbox']==1){
			echo ' selected';
		}
		echo '>'._('For everyone').'</option>';
		echo '<option value="3"';
		if($U['eninbox']==3){
			echo ' selected';
		}
		echo '>'._('For members only').'</option>';
		echo '<option value="5"';
		if($U['eninbox']==5){
			echo ' selected';
		}
		echo '>'._('For staff only').'</option>';
		echo '</select></td></tr></table></td></tr>';
		thr();
	}
	echo '<tr><td><table id="tz"><tr><th>'._('Time zone').'</th><td>';
	echo '<select name="tz">';
	$tzs=timezone_identifiers_list();
	foreach($tzs as $tz){
		echo "<option value=\"$tz\"";
		if($U['tz']==$tz){
			echo ' selected';
		}
		echo ">$tz</option>";
	}
	echo '</select></td></tr></table></td></tr>';
	thr();
	if($U['status']>=2){
		echo '<tr><td><table id="changepass"><tr><th>'._('Change Password').'</th></tr>';
		echo '<tr><td><table>';
		echo '<tr><td>&nbsp;</td><td>'._('Old password:').'</td><td><input type="password" name="oldpass" size="20" autocomplete="current-password"></td></tr>';
		echo '<tr><td>&nbsp;</td><td>'._('New password:').'</td><td><input type="password" name="newpass" size="20" autocomplete="new-password"></td></tr>';
		echo '<tr><td>&nbsp;</td><td>'._('Confirm new password:').'</td><td><input type="password" name="confirmpass" size="20" autocomplete="new-password"></td></tr>';
		echo '</table></td></tr></table></td></tr>';
		thr();
		echo '<tr><td><table id="changenick"><tr><th>'._('Change Nickname').'</th><td><table>';
		echo '<tr><td>&nbsp;</td><td>'._('New nickname:').'</td><td><input type="text" name="newnickname" size="20" autocomplete="username">';
		echo '</table></td></tr></table></td></tr>';
		thr();
	}
	echo '<tr><td>'.submit(_('Save changes')).'</td></tr></table></form>';
	if($U['status']>1 && $U['status']<8){
		echo '<br>'.form('profile', 'delete').submit(_('Delete account'), 'class="delbutton"').'</form>';
	}
	echo '<br><p id="changelang">'._('Change language:');
	foreach(LANGUAGES as $lang=>$data){
		echo " <a href=\"$_SERVER[SCRIPT_NAME]?lang=$lang&amp;session=$U[session]&amp;action=controls\" target=\"controls\">$data[name]</a>";
	}
	echo '</p><br>'.form('view').submit(_('Back to the chat.'), 'class="backbutton"').'</form>';
	print_end();
}

function send_controls(): void
{
	global $U;
	print_start('controls');
	$personalnotes=(bool) get_setting('personalnotes');
	$publicnotes=(bool) get_setting('publicnotes');
	$hide_reload_post_box=(bool) get_setting('hide_reload_post_box');
	$hide_reload_messages=(bool) get_setting('hide_reload_messages');
	$hide_profile=(bool) get_setting('hide_profile');
	$hide_admin=(bool) get_setting('hide_admin');
	$hide_notes=(bool) get_setting('hide_notes');
	$hide_clone=(bool) get_setting('hide_clone');
	$hide_rearrange=(bool) get_setting('hide_rearrange');
	$hide_help=(bool) get_setting('hide_help');
	echo '<table><tr>';
	if(!$hide_reload_post_box) {
		echo '<td>' . form_target( 'post', 'post' ) . submit( _('Reload Post Box') ) . '</form></td>';
	}
	if(!$hide_reload_messages) {
		echo '<td>' . form_target( 'view', 'view' ) . submit( _('Reload Messages') ) . '</form></td>';
	}
	if(!$hide_profile) {
		echo '<td>' . form_target( 'view', 'profile' ) . submit( _('Profile') ) . '</form></td>';
	}
	if($U['status']>=5){
		if(!$hide_admin) {
			echo '<td>' . form_target( 'view', 'admin' ) . submit( _('Admin') ) . '</form></td>';
		}
		if(!$personalnotes && !$hide_notes){
			echo '<td>'.form_target('view', 'notes', 'staff').submit(_('Notes')).'</form></td>';
		}
	}
	if($publicnotes){
		echo '<td>'.form_target('view', 'viewpublicnotes').submit(_('View public notes')).'</form></td>';
	}
	if($U['status']>=3){
		if($personalnotes || $publicnotes){
			echo '<td>'.form_target('view', 'notes').submit(_('Notes')).'</form></td>';
		}
		if(!$hide_clone) {
			echo '<td>' . form_target( '_blank', 'login' ) . submit( _('Clone') ) . '</form></td>';
		}
	}
	if(!isset($_GET['sort'])){
		$sort=0;
	}else{
		$sort=1;
	}
	if(!$hide_rearrange) {
		echo '<td>' . form_target( '_parent', 'login' ) . hidden( 'sort', $sort ) . submit( _('Rearrange') ) . '</form></td>';
	}
	if(!$hide_help) {
		echo '<td>' . form_target( 'view', 'help' ) . submit( _('Rules & Help') ) . '</form></td>';
	}
	echo '<td>'.form_target('_parent', 'logout').submit(_('Exit Chat'), 'id="exitbutton"').'</form></td>';
	echo '</tr></table>';
	print_end();
}

function send_download(): void
{
	global $db;
	if(isset($_GET['id'])){
		$stmt=$db->prepare('SELECT filename, type, data FROM ' . PREFIX . 'files WHERE hash=?;');
		$stmt->execute([$_GET['id']]);
		if($data=$stmt->fetch(PDO::FETCH_ASSOC)){
			send_headers();
			header("Content-Type: $data[type]");
			header("Content-Disposition: filename=\"$data[filename]\"");
			header("Content-Security-Policy: default-src 'none'");
			echo base64_decode($data['data']);
		}else{
			http_response_code(404);
			send_error(_('File not found!'));
		}
	}else{
		http_response_code(404);
		send_error(_('File not found!'));
	}
}

function send_logout(): void
{
	global $U;
	print_start('logout');
	echo '<h1>'.sprintf(_('Bye %s, visit again soon!'), style_this(htmlspecialchars($U['nickname']), $U['style'])).'</h1>'.form_target('_parent', '').submit(_('Back to the login page.'), 'class="backbutton"').'</form>';
	print_end();
}

function send_colours(): void
{
	print_start('colours');
	echo '<h2>'._('Colourtable').'</h2><kbd><b>';
	for($red=0x00;$red<=0xFF;$red+=0x33){
		for($green=0x00;$green<=0xFF;$green+=0x33){
			for($blue=0x00;$blue<=0xFF;$blue+=0x33){
				$hcol=sprintf('%02X%02X%02X', $red, $green, $blue);
				echo "<span style=\"color:#$hcol\">$hcol</span> ";
			}
			echo '<br>';
		}
		echo '<br>';
	}
	echo '</b></kbd>'.form('profile').submit(_('Back to your Profile'), ' class="backbutton"').'</form>';
	print_end();
}

function send_login(): void
{
	$ga=(int) get_setting('guestaccess');
	if($ga===4){
		send_chat_disabled();
	}
	print_start('login');
	$englobal=(int) get_setting('englobalpass');
	echo '<h1 id="chatname">'.get_setting('chatname').'</h1>';
	echo form_target('_parent', 'login');
	if($englobal===1 && isset($_POST['globalpass'])){
		echo hidden('globalpass', htmlspecialchars($_POST['globalpass']));
	}
	echo '<table>';
	if($englobal!==1 || (isset($_POST['globalpass']) && $_POST['globalpass']==get_setting('globalpass'))){
		echo '<tr><td>'._('Nickname:').'</td><td><input type="text" name="nick" size="15" autocomplete="username" autofocus></td></tr>';
		echo '<tr><td>'._('Password:').'</td><td><input type="password" name="pass" size="15" autocomplete="current-password"></td></tr>';
		send_captcha();
		if($ga!==0){
			if(get_setting('guestreg')!=0){
				echo '<tr><td>'._('Repeat password<br>to register').'</td><td><input type="password" name="regpass" size="15" placeholder="'._('(optional)').'" autocomplete="new-password"></td></tr>';
			}
			if($englobal===2){
				echo '<tr><td>'._('Global Password:').'</td><td><input type="password" name="globalpass" size="15"></td></tr>';
			}
			echo '<tr><td colspan="2">'._('Guests, choose a colour:').'<br><select name="colour"><option value="">* '._('Random Colour').' *</option>';
			print_colours();
			echo '</select></td></tr>';
		}else{
			echo '<tr><td colspan="2">'._('Sorry, currently members only!').'</td></tr>';
		}
		echo '<tr><td colspan="2">'.submit(_('Enter Chat')).'</td></tr></table></form>';
		get_nowchatting();
		echo '<br><div id="topic">';
		echo get_setting('topic');
		echo '</div>';
		$rulestxt=get_setting('rulestxt');
		if(!empty($rulestxt)){
			echo '<div id="rules"><h2>'._('Rules')."</h2><b>$rulestxt</b></div>";
		}
	}else{
		echo '<tr><td>'._('Global Password:').'</td><td><input type="password" name="globalpass" size="15" autofocus></td></tr>';
		if($ga===0){
			echo '<tr><td colspan="2">'._('Sorry, currently members only!').'</td></tr>';
		}
		echo '<tr><td colspan="2">'.submit(_('Enter Chat')).'</td></tr></table></form>';
	}
	echo '<p id="changelang">'._('Change language:');
	foreach(LANGUAGES as $lang=>$data){
		echo " <a href=\"$_SERVER[SCRIPT_NAME]?lang=$lang\">$data[name]</a>";
	}
	echo '</p>'.credit();
	print_end();
}

function send_chat_disabled(): void
{
	print_start('disabled');
	echo get_setting('disabletext');
	print_end();
}

function send_error(string $err): void
{
	print_start('error');
	echo '<h2>'.sprintf(_('Error: %s'),  $err).'</h2>'.form_target('_parent', '').submit(_('Back to the login page.'), 'class="backbutton"').'</form>';
	print_end();
}

function send_fatal_error(string $err): void
{
	global $language, $styles, $dir;
	prepare_stylesheets('fatal_error');
	send_headers();
	echo '<!DOCTYPE html><html lang="'.$language.'" dir="'.$dir.'"><head>'.meta_html();
	echo '<title>'._('Fatal error').'</title>';
	echo "<style>$styles[fatal_error]</style>";
	echo '</head><body>';
	echo '<h2>'.sprintf(_('Fatal error: %s'),  $err).'</h2>';
	print_end();
}

function print_notifications(): void
{
	global $U, $db;
	echo '<span id="notifications">';
	$stmt=$db->prepare('SELECT loginfails FROM ' . PREFIX . 'members WHERE nickname=?;');
	$stmt->execute([$U['nickname']]);
	$temp=$stmt->fetch(PDO::FETCH_NUM);
	if($temp && $temp[0]>0){
		echo '<p align="middle">' . $temp[0] . "&nbsp;" . _('Failed login attempt(s)') . "</p>";
	}
	if($U['status']>=2 && $U['eninbox']!=0){
		$stmt=$db->prepare('SELECT COUNT(*) FROM ' . PREFIX . 'inbox WHERE recipient=?;');
		$stmt->execute([$U['nickname']]);
		$tmp=$stmt->fetch(PDO::FETCH_NUM);
		if($tmp[0]>0){
			echo '<p>'.form('inbox').submit(sprintf(_('Read %d messages in your inbox'), $tmp[0])).'</form></p>';
		}
	}
	if($U['status']>=5 && get_setting('guestaccess')==3){
		$result=$db->query('SELECT COUNT(*) FROM ' . PREFIX . 'sessions WHERE entry=0 AND status=1;');
		$temp=$result->fetch(PDO::FETCH_NUM);
		if($temp[0]>0){
			echo '<p>';
			echo form('admin', 'approve');
			echo submit(sprintf(_('%d new guests to approve'), $temp[0])).'</form></p>';
		}
	}
	echo '</span>';
}

function print_chatters(): void
{
	global $U, $db, $language;
	if(!$U['hidechatters']){
		echo '<div id="chatters"><table><tr>';
		$stmt=$db->prepare('SELECT nickname, style, status FROM ' . PREFIX . 'sessions WHERE entry!=0 AND status>0 AND incognito=0 AND nickname NOT IN (SELECT ign FROM '. PREFIX . 'ignored WHERE ignby=? UNION SELECT ignby FROM '. PREFIX . 'ignored WHERE ign=?) ORDER BY status DESC, lastpost DESC;');
		$stmt->execute([$U['nickname'], $U['nickname']]);
		$nc=substr(time(), -6);
		$G=$M=$S=$A=[];
		$channellink="<a class=\"channellink\" href=\"$_SERVER[SCRIPT_NAME]?action=post&amp;session=$U[session]&amp;lang=$language&amp;nc=$nc&amp;sendto=";
		$nicklink="<a class=\"nicklink\" href=\"$_SERVER[SCRIPT_NAME]?action=post&amp;session=$U[session]&amp;lang=$language&amp;nc=$nc&amp;sendto=";
		while($user=$stmt->fetch(PDO::FETCH_NUM)){
			$link=$nicklink.urlencode($user[0]).'" target="post">'.style_this(htmlspecialchars($user[0]), $user[1]).'</a>';
			if($user[2]<3){ // guest or superguest
				$G[]=$link;
			} elseif($user[2]>=7){ // admin or superadmin
				$A[]=$link;
			} elseif(($user[2]>=5) && ($user[2]<=6)){ // moderator or supermoderator
				$S[]=$link;
			} elseif($user[2]=3){ // member
				$M[]=$link;
			}
		}
		if($U['status']>5){ // can chat in admin channel
				echo '<th>' . $channellink . 's _" target="post">' . _('Admin') . ':</a></th><td>&nbsp;</td><td>'.implode(' &nbsp; ', $A).'</td>';
			} else {
				echo '<th>'._('Admin:').'</th><td>&nbsp;</td><td>'.implode(' &nbsp; ', $A).'</td>';
		}
		if($U['status']>4){ // can chat in staff channel
				echo '<th>' . $channellink . 's &#37;" target="post">' . _('Staff') . ':</a></th><td>&nbsp;</td><td>'.implode(' &nbsp; ', $S).'</td>';
			} else {
				echo '<th>'._('Staff:').'</th><td>&nbsp;</td><td>'.implode(' &nbsp; ', $S).'</td>';
		}
		if($U['status']>=3){ // can chat in member channel
			echo '<th>' . $channellink . 's ?" target="post">' . _('Members') . ':</a></th><td>&nbsp;</td><td class="chattername">'.implode(' &nbsp; ', $M).'</td>';
		} else {
			echo '<th>'._('Members:').'</th><td>&nbsp;</td><td>'.implode(' &nbsp; ', $M).'</td>';
		}
		echo '<th>' . $channellink . 's *" target="post">' . _('Guests') . ':</a></th><td>&nbsp;</td><td class="chattername">'.implode(' &nbsp; ', $G).'</td>';
		echo '</tr></table></div>';
	}
}

//  session management

function create_session(bool $setup, string $nickname, string $password): void
{
	global $U;
	$U['nickname']=preg_replace('/\s/', '', $nickname);
	if(check_member($password)){
		if($setup && $U['status']>=7){
			$U['incognito']=1;
		}
		$U['entry']=$U['lastpost']=time();
	}else{
		add_user_defaults($password);
		check_captcha($_POST['challenge'] ?? '', $_POST['captcha'] ?? '');
		$ga=(int) get_setting('guestaccess');
		if(!valid_nick($U['nickname'])){
			send_error(sprintf(_('Invalid nickname (%1$d characters maximum and has to match the regular expression "%2$s")'), get_setting('maxname'), get_setting('nickregex')));
		}
		if(!valid_pass($password)){
			send_error(sprintf(_('Invalid password (At least %1$d characters and has to match the regular expression "%2$s")'), get_setting('minpass'), get_setting('passregex')));
		}
		if($ga===0){
			send_error(_('Sorry, currently members only!'));
		}elseif(in_array($ga, [2, 3], true)){
			$U['entry'] = 0;
		}
		if(get_setting('englobalpass')!=0 && isset($_POST['globalpass']) && $_POST['globalpass']!=get_setting('globalpass')){
			send_error(_('Wrong global Password!'));
		}
	}
	try {
		$U[ 'postid' ] = bin2hex( random_bytes( 3 ) );
	} catch(Exception $e) {
		send_error($e->getMessage());
	}
	write_new_session($password);
}

function check_captcha(string $challenge, string $captcha_code): void
{
	global $db, $memcached;
	$captcha=(int) get_setting('captcha');
	if($captcha!==0){
		if(empty($challenge)){
			send_error(_('Wrong Captcha'));
		}
		$code = '';
		if(MEMCACHED){
			if(!$code=$memcached->get(DBNAME . '-' . PREFIX . "captcha-$_POST[challenge]")){
				send_error(_('Captcha already used or timed out.'));
			}
			$memcached->delete(DBNAME . '-' . PREFIX . "captcha-$_POST[challenge]");
		}else{
			$stmt=$db->prepare('SELECT code FROM ' . PREFIX . 'captcha WHERE id=?;');
			$stmt->execute([$challenge]);
			$stmt->bindColumn(1, $code);
			if(!$stmt->fetch(PDO::FETCH_BOUND)){
				send_error(_('Captcha already used or timed out.'));
			}
			$time=time();
			$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'captcha WHERE id=? OR time<(?-(SELECT value FROM ' . PREFIX . "settings WHERE setting='captchatime'));");
			$stmt->execute([$challenge, $time]);
		}
		if($captcha_code!==$code){
			if($captcha!==3 || strrev($captcha_code)!==$code){
				send_error(_('Wrong Captcha'));
			}
		}
	}
}

function is_definitely_ssl() : bool {
	if (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') {
		return true;
	}
	if (isset($_SERVER['SERVER_PORT']) && ('443' == $_SERVER['SERVER_PORT'])) {
		return true;
	}
	if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && ('https' === $_SERVER['HTTP_X_FORWARDED_PROTO'])) {
		return true;
	}
	return false;
}

function set_secure_cookie(string $name, string $value): void
{
	if (version_compare(PHP_VERSION, '7.3.0') >= 0) {
		setcookie($name, $value, ['expires' => 0, 'path' => '/', 'domain' => '', 'secure' => is_definitely_ssl(), 'httponly' => true, 'samesite' => 'Strict']);
	}else{
		setcookie($name, $value, 0, '/', '', is_definitely_ssl(), true);
	}
}

function write_new_session(string $password): void
{
	global $U, $db, $session;
	$stmt=$db->prepare('SELECT * FROM ' . PREFIX . 'sessions WHERE nickname=?;');
	$stmt->execute([$U['nickname']]);
	if($temp=$stmt->fetch(PDO::FETCH_ASSOC)){
		// check whether alrady logged in
		if(password_verify($password, $temp['passhash'])){
			$U=$temp;
			check_kicked();
			set_secure_cookie(COOKIENAME, $U['session']);
		}else{
			send_error(_('A user with this nickname is already logged in.')."<br>"._('Wrong Password!'));
		}
	}else{
		// create new session
		$stmt=$db->prepare('SELECT null FROM ' . PREFIX . 'sessions WHERE session=?;');
		do{
			try {
				$U[ 'session' ] = bin2hex( random_bytes( 16 ) );
			} catch(Exception $e) {
				send_error($e->getMessage());
			}
			$stmt->execute([$U['session']]);
		}while($stmt->fetch(PDO::FETCH_NUM)); // check for hash collision
		if(isset($_SERVER['HTTP_USER_AGENT'])){
			$useragent=htmlspecialchars($_SERVER['HTTP_USER_AGENT']);
		}else{
			$useragent='';
		}
		if(get_setting('trackip')){
			$ip=$_SERVER['REMOTE_ADDR'];
		}else{
			$ip='';
		}
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'sessions (session, nickname, status, refresh, style, lastpost, passhash, useragent, bgcolour, entry, timestamps, embed, incognito, ip, nocache, tz, eninbox, sortupdown, hidechatters, nocache_old, postid) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);');
		$stmt->execute([$U['session'], $U['nickname'], $U['status'], $U['refresh'], $U['style'], $U['lastpost'], $U['passhash'], $useragent, $U['bgcolour'], $U['entry'], $U['timestamps'], $U['embed'], $U['incognito'], $ip, $U['nocache'], $U['tz'], $U['eninbox'], $U['sortupdown'], $U['hidechatters'], $U['nocache_old'], $U['postid']]);
		$session = $U['session'];
		set_secure_cookie(COOKIENAME, $U['session']);
		if($U['status']>=3 && !$U['incognito']){
			add_system_message(sprintf(get_setting('msgenter'), style_this(htmlspecialchars($U['nickname']), $U['style'])), '');
		}
	}
}

function show_fails(): void
{
	global $db, $U;
	$stmt=$db->prepare('SELECT loginfails FROM ' . PREFIX . 'members WHERE nickname=?;');
	$stmt->execute([$U['nickname']]);
	$temp=$stmt->fetch(PDO::FETCH_NUM);
	if($temp && $temp[0]>0){
		print_start('failednotice');
		echo $temp[0] . "&nbsp;" . _('Failed login attempt(s)') . "<br>";
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET loginfails=? WHERE nickname=?;');
		$stmt->execute([0, $U['nickname']]);
		echo form_target('_self', 'login').submit(_('Dismiss')).'</form></td>';
		print_end();
	}
}

function approve_session(): void
{
	global $db;
	if(isset($_POST['what'])){
		if($_POST['what']==='allowchecked' && isset($_POST['csid'])){
			$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET entry=lastpost WHERE nickname=?;');
			foreach($_POST['csid'] as $nick){
				$stmt->execute([$nick]);
			}
		}elseif($_POST['what']==='allowall' && isset($_POST['alls'])){
			$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET entry=lastpost WHERE nickname=?;');
			foreach($_POST['alls'] as $nick){
				$stmt->execute([$nick]);
			}
		}elseif($_POST['what']==='denychecked' && isset($_POST['csid'])){
			$time=60*(get_setting('kickpenalty')-get_setting('guestexpire'))+time();
			$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET lastpost=?, status=0, kickmessage=? WHERE nickname=? AND status=1;');
			foreach($_POST['csid'] as $nick){
				$stmt->execute([$time, $_POST['kickmessage'], $nick]);
			}
		}elseif($_POST['what']==='denyall' && isset($_POST['alls'])){
			$time=60*(get_setting('kickpenalty')-get_setting('guestexpire'))+time();
			$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET lastpost=?, status=0, kickmessage=? WHERE nickname=? AND status=1;');
			foreach($_POST['alls'] as $nick){
				$stmt->execute([$time, $_POST['kickmessage'], $nick]);
			}
		}
	}
}

function check_login(): void
{
	global $U;
	$ga=(int) get_setting('guestaccess');
	parse_sessions();
	if(isset($U['session'])){
		check_kicked();
	}elseif(get_setting('englobalpass')==1 && (!isset($_POST['globalpass']) || $_POST['globalpass']!=get_setting('globalpass'))){
		send_error(_('Wrong global Password!'));
	}elseif(!isset($_POST['nick']) || !isset($_POST['pass'])){
		send_login();
	}else{
		if($ga===4){
			send_chat_disabled();
		}
		if(!empty($_POST['regpass']) && $_POST['regpass']!==$_POST['pass']){
			send_error(_('Password confirmation does not match!'));
		}
		create_session(false, $_POST['nick'], $_POST['pass']);
		if(!empty($_POST['regpass'])){
			$guestreg=(int) get_setting('guestreg');
			if($guestreg===1){
				register_guest(2, $_POST['nick']);
				$U['status']=2;
			}elseif($guestreg===2){
				register_guest(3, $_POST['nick']);
				$U['status']=3;
			}
		}
	}
	if($U['status']==1){
		if(in_array($ga, [2, 3], true)){
			send_waiting_room();
		}
	}
}

function kill_session(): void
{
	global $U, $db, $session;
	parse_sessions();
	check_expired();
	check_kicked();
	setcookie(COOKIENAME, false);
	$session = '';
	$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'sessions WHERE session=?;');
	$stmt->execute([$U['session']]);
	if($U['status']>=3 && !$U['incognito']){
		add_system_message(sprintf(get_setting('msgexit'), style_this(htmlspecialchars($U['nickname']), $U['style'])), '');
	}
}

function kick_chatter(array $names, string $mes, bool $purge) : bool {
	global $U, $db;
	$lonick='';
	$time=60*(get_setting('kickpenalty')-get_setting('guestexpire'))+time();
	$check=$db->prepare('SELECT style, entry FROM ' . PREFIX . 'sessions WHERE nickname=? AND status!=0 AND (status<? OR nickname=?);');
	$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET lastpost=?, status=0, kickmessage=? WHERE nickname=?;');
	$all=false;
	if($names[0]==='s _'){
		$tmp=$db->query('SELECT nickname FROM ' . PREFIX . 'sessions WHERE status=1;');
		$names=[];
		while($name=$tmp->fetch(PDO::FETCH_NUM)){
			$names[]=$name[0];
		}
		$all=true;
	}
	$i=0;
	foreach($names as $name){
		$check->execute([$name, $U['status'], $U['nickname']]);
		if($temp=$check->fetch(PDO::FETCH_ASSOC)){
			$stmt->execute([$time, $mes, $name]);
			if($purge){
				del_all_messages($name, (int) $temp['entry']);
			}
			$lonick.=style_this(htmlspecialchars($name), $temp['style']).', ';
			++$i;
		}
	}
	if($i>0){
		if($all){
			add_system_message(get_setting('msgallkick'), $U['nickname']);
		}else{
			$lonick=substr($lonick, 0, -2);
			if($i>1){
				add_system_message(sprintf(get_setting('msgmultikick'), $lonick), $U['nickname']);
			}else{
				add_system_message(sprintf(get_setting('msgkick'), $lonick), $U['nickname']);
			}
		}
		return true;
	}
	return false;
}

function logout_chatter(array $names): void
{
	global $U, $db;
	$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'sessions WHERE nickname=? AND status<?;');
	if($names[0]==='s _'){
		$tmp=$db->query('SELECT nickname FROM ' . PREFIX . 'sessions WHERE status=1;');
		$names=[];
		while($name=$tmp->fetch(PDO::FETCH_NUM)){
			$names[]=$name[0];
		}
	}
	foreach($names as $name){
		$stmt->execute([$name, $U['status']]);
	}
}

function check_session(): void
{
	global $U;
	parse_sessions();
	check_expired();
	check_kicked();
	if($U['entry']==0){
		send_waiting_room();
	}
}

function check_expired(): void
{
	global $U, $session;
	if(!isset($U['session'])){
		setcookie(COOKIENAME, false);
		$session = '';
		send_error(_('Invalid/expired session'));
	}
}

function get_count_mods() : int {
	global $db;
	$c=$db->query('SELECT COUNT(*) FROM ' . PREFIX . 'sessions WHERE status>=5')->fetch(PDO::FETCH_NUM);
	return (int) $c[0];
}

function check_kicked(): void
{
	global $U, $session;
	if($U['status']==0){
		setcookie(COOKIENAME, false);
		$session = '';
		send_error(_('You have been kicked!')."<br>$U[kickmessage]");
	}
}

function get_nowchatting(): void
{
	global $db;
	parse_sessions();
	$stmt=$db->query('SELECT COUNT(*) FROM ' . PREFIX . 'sessions WHERE entry!=0 AND status>0 AND incognito=0;');
	$count=$stmt->fetch(PDO::FETCH_NUM);
	echo '<div id="chatters">'.sprintf(_('Currently %d chatter(s) in room:'), $count[0]).'<br>';
	if(!get_setting('hidechatters')){
		$stmt=$db->query('SELECT nickname, style FROM ' . PREFIX . 'sessions WHERE entry!=0 AND status>0 AND incognito=0 ORDER BY status DESC, lastpost DESC;');
		while($user=$stmt->fetch(PDO::FETCH_NUM)){
			echo style_this(htmlspecialchars($user[0]), $user[1]).' &nbsp; ';
		}
	}
	echo '</div>';
}

function parse_sessions(): void
{
	global $U, $db, $session;
	// look for our session
	if(!empty($session)){
		$stmt=$db->prepare('SELECT * FROM ' . PREFIX . 'sessions WHERE session=?;');
		$stmt->execute([$session]);
		if($tmp=$stmt->fetch(PDO::FETCH_ASSOC)){
			$U=$tmp;
		}
	}
	set_default_tz();
}

//  member handling

function check_member(string $password) : bool {
	global $U, $db;
	$stmt=$db->prepare('SELECT * FROM ' . PREFIX . 'members WHERE nickname=?;');
	$stmt->execute([$U['nickname']]);
	if($temp=$stmt->fetch(PDO::FETCH_ASSOC)){
		if(get_setting('dismemcaptcha')==0){
			check_captcha($_POST['challenge'] ?? '', $_POST['captcha'] ?? '');
		}
		if($temp['passhash']===md5(sha1(md5($U['nickname'].$password)))){
			// old hashing method, update on the fly
			$temp['passhash']=password_hash($password, PASSWORD_DEFAULT);
			$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET passhash=? WHERE nickname=?;');
			$stmt->execute([$temp['passhash'], $U['nickname']]);
		}
		if(password_verify($password, $temp['passhash'])){
			$U=$temp;
			$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET lastlogin=? WHERE nickname=?;');
			$stmt->execute([time(), $U['nickname']]);
			return true;
		}else{
			$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET loginfails=? WHERE nickname=?;');
			$stmt->execute([$temp['loginfails']+1, $temp['nickname']]);
			send_error(_('This nickname is a registered member.')."<br>"._('Wrong Password!'));
		}
	}
	return false;
}

function delete_account(): void
{
	global $U, $db;
	if($U['status']<8){
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET status=1, incognito=0 WHERE nickname=?;');
		$stmt->execute([$U['nickname']]);
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'members WHERE nickname=?;');
		$stmt->execute([$U['nickname']]);
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'inbox WHERE recipient=?;');
		$stmt->execute([$U['nickname']]);
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'notes WHERE (type=2 OR type=3) AND editedby=?;');
		$stmt->execute([$U['nickname']]);
		$U['status']=1;
	}
}

function register_guest(int $status, string $nick) : string {
	global $U, $db;
	$stmt=$db->prepare('SELECT style FROM ' . PREFIX . 'members WHERE nickname=?');
	$stmt->execute([$nick]);
	if($tmp=$stmt->fetch(PDO::FETCH_NUM)){
		return sprintf(_('%s is already registered.'), style_this(htmlspecialchars($nick), $tmp[0]));
	}
	$stmt=$db->prepare('SELECT * FROM ' . PREFIX . 'sessions WHERE nickname=? AND status=1;');
	$stmt->execute([$nick]);
	if($reg=$stmt->fetch(PDO::FETCH_ASSOC)){
		$reg['status']=$status;
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET status=? WHERE session=?;');
		$stmt->execute([$reg['status'], $reg['session']]);
	}else{
		return sprintf(_("Can't register %s"), htmlspecialchars($nick));
	}
	$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'members (nickname, passhash, status, refresh, bgcolour, regedby, timestamps, embed, style, incognito, nocache, tz, eninbox, sortupdown, hidechatters, nocache_old) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);');
	$stmt->execute([$reg['nickname'], $reg['passhash'], $reg['status'], $reg['refresh'], $reg['bgcolour'], $U['nickname'], $reg['timestamps'], $reg['embed'], $reg['style'], $reg['incognito'], $reg['nocache'], $reg['tz'], $reg['eninbox'], $reg['sortupdown'], $reg['hidechatters'], $reg['nocache_old']]);
	if($reg['status']==3){
		add_system_message(sprintf(get_setting('msgmemreg'), style_this(htmlspecialchars($reg['nickname']), $reg['style'])), $U['nickname']);
	}else{
		add_system_message(sprintf(get_setting('msgsureg'), style_this(htmlspecialchars($reg['nickname']), $reg['style'])), $U['nickname']);
	}
	return sprintf(_('%s successfully registered.'), style_this(htmlspecialchars($reg['nickname']), $reg['style']));
}

function register_new(string $nick, string $pass) : string {
	global $U, $db;
	$nick=preg_replace('/\s/', '', $nick);
	if(empty($nick)){
		return '';
	}
	$stmt=$db->prepare('SELECT null FROM ' . PREFIX . 'sessions WHERE nickname=?');
	$stmt->execute([$nick]);
	if($stmt->fetch(PDO::FETCH_NUM)){
		return sprintf(_("Can't register %s"), htmlspecialchars($nick));
	}
	if(!valid_nick($nick)){
		return sprintf(_('Invalid nickname (%1$d characters maximum and has to match the regular expression "%2$s")'), get_setting('maxname'), get_setting('nickregex'));
	}
	if(!valid_pass($pass)){
		return sprintf(_('Invalid password (At least %1$d characters and has to match the regular expression "%2$s")'), get_setting('minpass'), get_setting('passregex'));
	}
	$stmt=$db->prepare('SELECT null FROM ' . PREFIX . 'members WHERE nickname=?');
	$stmt->execute([$nick]);
	if($stmt->fetch(PDO::FETCH_NUM)){
		return sprintf(_('%s is already registered.'), htmlspecialchars($nick));
	}
	$reg=[
		'nickname'	=>$nick,
		'passhash'	=>password_hash($pass, PASSWORD_DEFAULT),
		'status'	=>3,
		'refresh'	=>get_setting('defaultrefresh'),
		'bgcolour'	=>get_setting('colbg'),
		'regedby'	=>$U['nickname'],
		'timestamps'	=>get_setting('timestamps'),
		'style'		=>'color:#'.get_setting('coltxt').';',
		'embed'		=>1,
		'incognito'	=>0,
		'nocache'	=>0,
		'nocache_old'	=>1,
		'tz'		=>get_setting('defaulttz'),
		'eninbox'	=>0,
		'sortupdown'	=>get_setting('sortupdown'),
		'hidechatters'	=>get_setting('hidechatters'),
	];
	$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'members (nickname, passhash, status, refresh, bgcolour, regedby, timestamps, style, embed, incognito, nocache, tz, eninbox, sortupdown, hidechatters, nocache_old) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);');
	$stmt->execute([$reg['nickname'], $reg['passhash'], $reg['status'], $reg['refresh'], $reg['bgcolour'], $reg['regedby'], $reg['timestamps'], $reg['style'], $reg['embed'], $reg['incognito'], $reg['nocache'], $reg['tz'], $reg['eninbox'], $reg['sortupdown'], $reg['hidechatters'], $reg['nocache_old']]);
	return sprintf(_('%s successfully registered.'), htmlspecialchars($reg['nickname']));
}

function change_status(string $nick, string $status) : string {
	global $U, $db;
	if(empty($nick)){
		return '';
	}elseif($U['status']<=$status || !preg_match('/^[023567\-]$/', $status)){
		return sprintf(_("Can't change status of %s"), htmlspecialchars($nick));
	}
	$stmt=$db->prepare('SELECT incognito, style FROM ' . PREFIX . 'members WHERE nickname=? AND status<?;');
	$stmt->execute([$nick, $U['status']]);
	if(!$old=$stmt->fetch(PDO::FETCH_NUM)){
		return sprintf(_("Can't change status of %s"), htmlspecialchars($nick));
	}
	if($status==='-'){
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'members WHERE nickname=?;');
		$stmt->execute([$nick]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET status=1, incognito=0 WHERE nickname=?;');
		$stmt->execute([$nick]);
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'inbox WHERE recipient=?;');
		$stmt->execute([$nick]);
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'notes WHERE (type=2 OR type=3) AND editedby=?;');
		$stmt->execute([$nick]);
		return sprintf(_('%s successfully deleted from database.'), style_this(htmlspecialchars($nick), $old[1]));
	}else{
		if($status<5){
			$old[0]=0;
		}
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET status=?, incognito=? WHERE nickname=?;');
		$stmt->execute([$status, $old[0], $nick]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET status=?, incognito=? WHERE nickname=?;');
		$stmt->execute([$status, $old[0], $nick]);
		return sprintf(_('Status of %s successfully changed.'), style_this(htmlspecialchars($nick), $old[1]));
	}
}

function passreset(string $nick, string $pass) : string {
	global $U, $db;
	if(empty($nick)){
		return '';
	}
	$stmt=$db->prepare('SELECT null FROM ' . PREFIX . 'members WHERE nickname=? AND status<?;');
	$stmt->execute([$nick, $U['status']]);
	if($stmt->fetch(PDO::FETCH_ASSOC)){
		$passhash=password_hash($pass, PASSWORD_DEFAULT);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET passhash=? WHERE nickname=?;');
		$stmt->execute([$passhash, $nick]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET passhash=? WHERE nickname=?;');
		$stmt->execute([$passhash, $nick]);
		return sprintf(_('Successfully reset password for %s'), htmlspecialchars($nick));
	}else{
		return sprintf(_("Can't reset password for %s"), htmlspecialchars($nick));
	}
}

function amend_profile(): void
{
	global $U;
	if(isset($_POST['refresh'])){
		$U['refresh']=$_POST['refresh'];
	}
	if($U['refresh']<5){
		$U['refresh']=5;
	}elseif($U['refresh']>150){
		$U['refresh']=150;
	}
	if(preg_match('/^#([a-f0-9]{6})$/i', $_POST['colour'], $match)){
		$colour=$match[1];
	}else{
		preg_match('/#([0-9a-f]{6})/i', $U['style'], $matches);
		$colour=$matches[1];
	}
	if(preg_match('/^#([a-f0-9]{6})$/i', $_POST['bgcolour'], $match)){
		$U['bgcolour']=$match[1];
	}
	$U['style']="color:#$colour;";
	if($U['status']>=3){
		$F=load_fonts();
		if(isset($F[$_POST['font']])){
			$U['style'].=$F[$_POST['font']];
		}
		if(isset($_POST['small'])){
			$U['style'].='font-size:smaller;';
		}
		if(isset($_POST['italic'])){
			$U['style'].='font-style:italic;';
		}
		if(isset($_POST['bold'])){
			$U['style'].='font-weight:bold;';
		}
	}
	if($U['status']>=5 && isset($_POST['incognito']) && get_setting('incognito')){
		$U['incognito']=1;
	}else{
		$U['incognito']=0;
	}
	if(isset($_POST['tz'])){
		$tzs=timezone_identifiers_list();
		if(in_array($_POST['tz'], $tzs)){
			$U['tz']=$_POST['tz'];
		}
	}
	if(isset($_POST['eninbox']) && $_POST['eninbox']>=0 && $_POST['eninbox']<=5){
		$U['eninbox']=$_POST['eninbox'];
	}
	$bool_settings=['timestamps', 'embed', 'nocache', 'sortupdown', 'hidechatters'];
	foreach($bool_settings as $setting){
		if(isset($_POST[$setting])){
			$U[$setting]=1;
		}else{
			$U[$setting]=0;
		}
	}
}

function save_profile() : string {
	global $U, $db;
	amend_profile();
	$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET refresh=?, style=?, bgcolour=?, timestamps=?, embed=?, incognito=?, nocache=?, tz=?, eninbox=?, sortupdown=?, hidechatters=? WHERE session=?;');
	$stmt->execute([$U['refresh'], $U['style'], $U['bgcolour'], $U['timestamps'], $U['embed'], $U['incognito'], $U['nocache'], $U['tz'], $U['eninbox'], $U['sortupdown'], $U['hidechatters'], $U['session']]);
	if($U['status']>=2){
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET refresh=?, bgcolour=?, timestamps=?, embed=?, incognito=?, style=?, nocache=?, tz=?, eninbox=?, sortupdown=?, hidechatters=? WHERE nickname=?;');
		$stmt->execute([$U['refresh'], $U['bgcolour'], $U['timestamps'], $U['embed'], $U['incognito'], $U['style'], $U['nocache'], $U['tz'], $U['eninbox'], $U['sortupdown'], $U['hidechatters'], $U['nickname']]);
	}
	if(!empty($_POST['unignore'])){
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'ignored WHERE ign=? AND ignby=?;');
		$stmt->execute([$_POST['unignore'], $U['nickname']]);
	}
	if(!empty($_POST['ignore'])){
		$stmt=$db->prepare('SELECT null FROM ' . PREFIX . 'messages WHERE poster=? AND poster NOT IN (SELECT ign FROM ' . PREFIX . 'ignored WHERE ignby=?);');
		$stmt->execute([$_POST['ignore'], $U['nickname']]);
		if($U['nickname']!==$_POST['ignore'] && $stmt->fetch(PDO::FETCH_NUM)){
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'ignored (ign, ignby) VALUES (?, ?);');
			$stmt->execute([$_POST['ignore'], $U['nickname']]);
		}
	}
	if($U['status']>1 && !empty($_POST['newpass'])){
		if(!valid_pass($_POST['newpass'])){
			return sprintf(_('Invalid password (At least %1$d characters and has to match the regular expression "%2$s")'), get_setting('minpass'), get_setting('passregex'));
		}
		if(!isset($_POST['oldpass'])){
			$_POST['oldpass']='';
		}
		if(!isset($_POST['confirmpass'])){
			$_POST['confirmpass']='';
		}
		if($_POST['newpass']!==$_POST['confirmpass']){
			return _('Password confirmation does not match!');
		}else{
			$U['newhash']=password_hash($_POST['newpass'], PASSWORD_DEFAULT);
		}
		if(!password_verify($_POST['oldpass'], $U['passhash'])){
			return _('Wrong Password!');
		}
		$U['passhash']=$U['newhash'];
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET passhash=? WHERE session=?;');
		$stmt->execute([$U['passhash'], $U['session']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET passhash=? WHERE nickname=?;');
		$stmt->execute([$U['passhash'], $U['nickname']]);
	}
	if($U['status']>1 && !empty($_POST['newnickname'])){
		$msg=set_new_nickname();
		if($msg!==''){
			return $msg;
		}
	}
	return _('Your profile has successfully been saved.');
}

function set_new_nickname() : string {
	global $U, $db;
	$_POST['newnickname']=preg_replace('/\s/', '', $_POST['newnickname']);
	if(!valid_nick($_POST['newnickname'])){
		return sprintf(_('Invalid nickname (%1$d characters maximum and has to match the regular expression "%2$s")'), get_setting('maxname'), get_setting('nickregex'));
	}
	$stmt=$db->prepare('SELECT id FROM ' . PREFIX . 'sessions WHERE nickname=? UNION SELECT id FROM ' . PREFIX . 'members WHERE nickname=?;');
	$stmt->execute([$_POST['newnickname'], $_POST['newnickname']]);
	if($stmt->fetch(PDO::FETCH_NUM)){
		return _('Nickname is already taken');
	}else{
		// Make sure members can not read private messages of previous guests with the same name
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'messages SET poster = "" WHERE poster = ? AND poststatus = 9;');
		$stmt->execute([$_POST['newnickname']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'messages SET recipient = "" WHERE recipient = ? AND poststatus = 9;');
		$stmt->execute([$_POST['newnickname']]);
		// change names in all tables
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET nickname=? WHERE nickname=?;');
		$stmt->execute([$_POST['newnickname'], $U['nickname']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET nickname=? WHERE nickname=?;');
		$stmt->execute([$_POST['newnickname'], $U['nickname']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'messages SET poster=? WHERE poster=?;');
		$stmt->execute([$_POST['newnickname'], $U['nickname']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'messages SET recipient=? WHERE recipient=?;');
		$stmt->execute([$_POST['newnickname'], $U['nickname']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'ignored SET ignby=? WHERE ignby=?;');
		$stmt->execute([$_POST['newnickname'], $U['nickname']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'ignored SET ign=? WHERE ign=?;');
		$stmt->execute([$_POST['newnickname'], $U['nickname']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'inbox SET poster=? WHERE poster=?;');
		$stmt->execute([$_POST['newnickname'], $U['nickname']]);
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'notes SET editedby=? WHERE editedby=?;');
		$stmt->execute([$_POST['newnickname'], $U['nickname']]);
		$U['nickname']=$_POST['newnickname'];
	}
	return '';
}

//sets default settings for guests
function add_user_defaults(string $password): void
{
	global $U;
	$U['refresh']=get_setting('defaultrefresh');
	$U['bgcolour']=get_setting('colbg');
	if(!isset($_POST['colour']) || !preg_match('/^[a-f0-9]{6}$/i', $_POST['colour']) || abs(greyval($_POST['colour'])-greyval(get_setting('colbg')))<75){
		do{
			$colour=sprintf('%06X', mt_rand(0, 16581375));
		}while(abs(greyval($colour)-greyval(get_setting('colbg')))<75);
	}else{
		$colour=$_POST['colour'];
	}
	$U['style']="color:#$colour;";
	$U['timestamps']=get_setting('timestamps');
	$U['embed']=1;
	$U['incognito']=0;
	$U['status']=1;
	$U['nocache']=get_setting('sortupdown');
	if($U['nocache']){
		$U['nocache_old']=0;
	}else{
		$U['nocache_old']=1;
	}
	$U['loginfails']=0;
	$U['tz']=get_setting('defaulttz');
	$U['eninbox']=0;
	$U['sortupdown']=get_setting('sortupdown');
	$U['hidechatters']=get_setting('hidechatters');
	$U['passhash']=password_hash($password, PASSWORD_DEFAULT);
	$U['entry']=$U['lastpost']=time();
}

// message handling

function validate_input() : string {
	global $U, $db;
	$inbox=false;
	$maxmessage=get_setting('maxmessage');
	$message=mb_substr($_POST['message'], 0, $maxmessage);
	$rejected=mb_substr($_POST['message'], $maxmessage);
	if(!isset($_POST['postid'])){ // auto-kick spammers not setting a postid
		kick_chatter([$U['nickname']], '', false);
	}
	if($U['postid'] !== $_POST['postid'] || (time() - $U['lastpost']) <= 1){ // reject bogus messages
		$rejected=$_POST['message'];
		$message='';
	}
	if(!empty($rejected)){
		$rejected=trim($rejected);
		$rejected=htmlspecialchars($rejected);
	}
	$message=htmlspecialchars($message);
	$message=preg_replace("/(\r?\n|\r\n?)/u", '<br>', $message);
	if(isset($_POST['multi'])){
		$message=preg_replace('/\s*<br>/u', '<br>', $message);
		$message=preg_replace('/<br>(<br>)+/u', '<br><br>', $message);
		$message=preg_replace('/<br><br>\s*$/u', '<br>', $message);
		$message=preg_replace('/^<br>\s*$/u', '', $message);
	}else{
		$message=str_replace('<br>', ' ', $message);
	}
	$message=trim($message);
	$message=preg_replace('/\s+/u', ' ', $message);
	$recipient='';
	if($_POST['sendto']==='s *'){
		$poststatus=1;
		$displaysend=sprintf(get_setting('msgsendall'), style_this(htmlspecialchars($U['nickname']), $U['style']));
	}elseif($_POST['sendto']==='s ?' && $U['status']>=3){
		$poststatus=3;
		$displaysend=sprintf(get_setting('msgsendmem'), style_this(htmlspecialchars($U['nickname']), $U['style']));
	}elseif($_POST['sendto']==='s %' && $U['status']>=5){
		$poststatus=5;
		$displaysend=sprintf(get_setting('msgsendmod'), style_this(htmlspecialchars($U['nickname']), $U['style']));
	}elseif($_POST['sendto']==='s _' && $U['status']>=6){
		$poststatus=6;
		$displaysend=sprintf(get_setting('msgsendadm'), style_this(htmlspecialchars($U['nickname']), $U['style']));
	}elseif($_POST['sendto'] === $U['nickname']){ // message to yourself?
		return '';
	}else{ // known nick in room?
		if(get_setting('disablepm')){
			//PMs disabled
			return '';
		}
		$stmt=$db->prepare('SELECT null FROM ' . PREFIX . 'ignored WHERE (ignby=? AND ign=?) OR (ign=? AND ignby=?);');
		$stmt->execute([$_POST['sendto'], $U['nickname'], $_POST['sendto'], $U['nickname']]);
		if($stmt->fetch(PDO::FETCH_NUM)){
			//ignored
			return '';
		}
		$stmt=$db->prepare('SELECT s.style, 0 AS inbox FROM ' . PREFIX . 'sessions AS s LEFT JOIN ' . PREFIX . 'members AS m ON (m.nickname=s.nickname) WHERE s.nickname=? AND (s.incognito=0 OR (m.eninbox!=0 AND m.eninbox<=?));');
		$stmt->execute([$_POST['sendto'], $U['status']]);
		if(!$tmp=$stmt->fetch(PDO::FETCH_ASSOC)){
			$stmt=$db->prepare('SELECT style, 1 AS inbox FROM ' . PREFIX . 'members WHERE nickname=? AND eninbox!=0 AND eninbox<=?;');
			$stmt->execute([$_POST['sendto'], $U['status']]);
			if(!$tmp=$stmt->fetch(PDO::FETCH_ASSOC)){
				//nickname left or disabled offline inbox for us
				return '';
			}
		}
		$recipient=$_POST['sendto'];
		$poststatus=9;
		$displaysend=sprintf(get_setting('msgsendprv'), style_this(htmlspecialchars($U['nickname']), $U['style']), style_this(htmlspecialchars($recipient), $tmp['style']));
		$inbox=$tmp['inbox'];
	}
	if($poststatus!==9 && preg_match('~^/me~iu', $message)){
		$displaysend=style_this(htmlspecialchars("$U[nickname] "), $U['style']);
		$message=preg_replace("~^/me\s?~iu", '', $message);
	}
	$message=apply_filter($message, $poststatus, $U['nickname']);
	$message=create_hotlinks($message);
	$message=apply_linkfilter($message);
	if(isset($_FILES['file']) && get_setting('enfileupload')>0 && get_setting('enfileupload')<=$U['status']){
		if($_FILES['file']['error']===UPLOAD_ERR_OK && $_FILES['file']['size']<=(1024*get_setting('maxuploadsize'))){
			$hash=sha1_file($_FILES['file']['tmp_name']);
			$name=htmlspecialchars($_FILES['file']['name']);
			$message=sprintf(get_setting('msgattache'), "<a class=\"attachement\" href=\"$_SERVER[SCRIPT_NAME]?action=download&amp;id=$hash\" target=\"_blank\">$name</a>", $message);
		}
	}
	if(add_message($message, $recipient, $U['nickname'], (int) $U['status'], $poststatus, $displaysend, $U['style'])){
		$U['lastpost']=time();
		try {
			$U[ 'postid' ] = bin2hex( random_bytes( 3 ) );
		} catch(Exception $e) {
			$U['postid'] = substr(time(), -6);
		}
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'sessions SET lastpost=?, postid=? WHERE session=?;');
		$stmt->execute([$U['lastpost'], $U['postid'], $U['session']]);
		$stmt=$db->prepare('SELECT id FROM ' . PREFIX . 'messages WHERE poster=? ORDER BY id DESC LIMIT 1;');
		$stmt->execute([$U['nickname']]);
		$id=$stmt->fetch(PDO::FETCH_NUM);
		if($inbox && $id){
			$newmessage=[
				'postdate'	=>time(),
				'poster'	=>$U['nickname'],
				'recipient'	=>$recipient,
				'text'		=>"<span class=\"usermsg\">$displaysend".style_this($message, $U['style']).'</span>'
			];
			if(MSGENCRYPTED){
				try {
					$newmessage[ 'text' ] = base64_encode( sodium_crypto_aead_aes256gcm_encrypt( $newmessage[ 'text' ], '', AES_IV, ENCRYPTKEY ) );
				} catch (SodiumException $e){
					send_error($e->getMessage());
				}
			}
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'inbox (postdate, postid, poster, recipient, text) VALUES(?, ?, ?, ?, ?)');
			$stmt->execute([$newmessage['postdate'], $id[0], $newmessage['poster'], $newmessage['recipient'], $newmessage['text']]);
		}
		if(isset($hash) && $id){
			if(function_exists('mime_content_type')){
				$type = mime_content_type($_FILES['file']['tmp_name']);
			}elseif(!empty($_FILES['file']['type']) && preg_match('~^[a-z0-9/\-.+]*$~i', $_FILES['file']['type'])){
				$type = $_FILES['file']['type'];
			}else{
				$type = 'application/octet-stream';
			}
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'files (postid, hash, filename, type, data) VALUES (?, ?, ?, ?, ?);');
			$stmt->execute([$id[0], $hash, str_replace('"', '\"', $_FILES['file']['name']), $type, base64_encode(file_get_contents($_FILES['file']['tmp_name']))]);
			unlink($_FILES['file']['tmp_name']);
		}
	}
	return $rejected;
}

function apply_filter(string $message, int $poststatus, string $nickname) : string {
	global $U, $session;
	$message=str_replace('<br>', "\n", $message);
	$message=apply_mention($message);
	$filters=get_filters();
	foreach($filters as $filter){
		if($poststatus!==9 || !$filter['allowinpm']){
			if($filter['cs']){
				$message=preg_replace("/$filter[match]/u", $filter['replace'], $message, -1, $count);
			}else{
				$message=preg_replace("/$filter[match]/iu", $filter['replace'], $message, -1, $count);
			}
		}
		if(isset($count) && $count>0 && $filter['kick'] && ($U['status']<5 || get_setting('filtermodkick'))){
			kick_chatter([$nickname], $filter['replace'], false);
			setcookie(COOKIENAME, false);
			$session = '';
			send_error(_('You have been kicked!')."<br>$filter[replace]");
		}
	}
	$message=str_replace("\n", '<br>', $message);
	return $message;
}

function apply_linkfilter(string $message) : string {
	$filters=get_linkfilters();
	foreach($filters as $filter){
		$message=preg_replace_callback("/<a href=\"([^\"]+)\" target=\"_blank\" rel=\"noreferrer noopener\">([^<]*)<\/a>/iu",
			function ($matched) use(&$filter){
				return "<a href=\"$matched[1]\" target=\"_blank\" rel=\"noreferrer noopener\">".preg_replace("/$filter[match]/iu", $filter['replace'], $matched[2]).'</a>';
			}
		, $message);
	}
	$redirect=get_setting('redirect');
	if(get_setting('imgembed')){
		$message=preg_replace_callback('/\[img]\s?<a href="([^"]+)" target="_blank" rel="noreferrer noopener">([^<]*)<\/a>/iu',
			function ($matched){
				return str_ireplace('[/img]', '', "<br><a href=\"$matched[1]\" target=\"_blank\" rel=\"noreferrer noopener\"><img src=\"$matched[1]\" rel=\"noreferrer\" loading=\"lazy\"></a><br>");
			}
		, $message);
	}
	if(empty($redirect)){
		$redirect="$_SERVER[SCRIPT_NAME]?action=redirect&amp;url=";
	}
	if(get_setting('forceredirect')){
		$message=preg_replace_callback('/<a href="([^"]+)" target="_blank" rel="noreferrer noopener">([^<]*)<\/a>/u',
			function ($matched) use($redirect){
				return "<a href=\"$redirect".rawurlencode($matched[1])."\" target=\"_blank\" rel=\"noreferrer noopener\">$matched[2]</a>";
			}
		, $message);
	}elseif(preg_match_all('/<a href="([^"]+)" target="_blank" rel="noreferrer noopener">([^<]*)<\/a>/u', $message, $matches)){
		foreach($matches[1] as $match){
			if(!preg_match('~^http(s)?://~u', $match)){
				$message=preg_replace_callback('/<a href="('.preg_quote($match, '/').')\" target=\"_blank\" rel=\"noreferrer noopener\">([^<]*)<\/a>/u',
					function ($matched) use($redirect){
						return "<a href=\"$redirect".rawurlencode($matched[1])."\" target=\"_blank\" rel=\"noreferrer noopener\">$matched[2]</a>";
					}
				, $message);
			}
		}
	}
	return $message;
}

function create_hotlinks(string $message) : string {
	//Make hotlinks for URLs, redirect through dereferrer script to prevent session leakage
	// 1. all explicit schemes with whatever xxx://yyyyyyy
	$message=preg_replace('~(^|[^\w"])(\w+://[^\s<>]+)~iu', "$1<<$2>>", $message);
	// 2. valid URLs without scheme:
	$message=preg_replace('~((?:[^\s<>]*:[^\s<>]*@)?[a-z0-9\-]+(?:\.[a-z0-9\-]+)+(?::\d*)?/[^\s<>]*)(?![^<>]*>)~iu', "<<$1>>", $message); // server/path given
	$message=preg_replace('~((?:[^\s<>]*:[^\s<>]*@)?[a-z0-9\-]+(?:\.[a-z0-9\-]+)+:\d+)(?![^<>]*>)~iu', "<<$1>>", $message); // server:port given
	$message=preg_replace('~([^\s<>]*:[^\s<>]*@[a-z0-9\-]+(?:\.[a-z0-9\-]+)+(?::\d+)?)(?![^<>]*>)~iu', "<<$1>>", $message); // au:th@server given
	// 3. likely servers without any hints but not filenames like *.rar zip exe etc.
	$message=preg_replace('~((?:[a-z0-9\-]+\.)*(?:[a-z2-7]{55}d|[a-z2-7]{16})\.onion)(?![^<>]*>)~iu', "<<$1>>", $message);// *.onion
	$message=preg_replace('~([a-z0-9\-]+(?:\.[a-z0-9\-]+)+(?:\.(?!rar|zip|exe|gz|7z|bat|doc)[a-z]{2,}))(?=[^a-z0-9\-.]|$)(?![^<>]*>)~iu', "<<$1>>", $message);// xxx.yyy.zzz
	// Convert every <<....>> into proper links:
	$message=preg_replace_callback('/<<([^<>]+)>>/u',
		function ($matches){
			if(strpos($matches[1], '://')===false){
				return "<a href=\"http://$matches[1]\" target=\"_blank\" rel=\"noreferrer noopener\">$matches[1]</a>";
			}else{
				return "<a href=\"$matches[1]\" target=\"_blank\" rel=\"noreferrer noopener\">$matches[1]</a>";
			}
		}
	, $message);
	return $message;
}

function apply_mention(string $message) : string {
	return preg_replace_callback('/@([^\s]+)/iu', function ($matched){
		global $db;
		$nick=htmlspecialchars_decode($matched[1]);
		$rest='';
		for($i=0;$i<=3;++$i){
			//match case-sensitive present nicknames
			$stmt=$db->prepare('SELECT style FROM ' . PREFIX . 'sessions WHERE nickname=?;');
			$stmt->execute([$nick]);
			if($tmp=$stmt->fetch(PDO::FETCH_NUM)){
				return style_this(htmlspecialchars("@$nick"), $tmp[0]).$rest;
			}
			//match case-insensitive present nicknames
			$stmt=$db->prepare('SELECT style FROM ' . PREFIX . 'sessions WHERE LOWER(nickname)=LOWER(?);');
			$stmt->execute([$nick]);
			if($tmp=$stmt->fetch(PDO::FETCH_NUM)){
				return style_this(htmlspecialchars("@$nick"), $tmp[0]).$rest;
			}
			//match case-sensitive members
			$stmt=$db->prepare('SELECT style FROM ' . PREFIX . 'members WHERE nickname=?;');
			$stmt->execute([$nick]);
			if($tmp=$stmt->fetch(PDO::FETCH_NUM)){
				return style_this(htmlspecialchars("@$nick"), $tmp[0]).$rest;
			}
			//match case-insensitive members
			$stmt=$db->prepare('SELECT style FROM ' . PREFIX . 'members WHERE LOWER(nickname)=LOWER(?);');
			$stmt->execute([$nick]);
			if($tmp=$stmt->fetch(PDO::FETCH_NUM)){
				return style_this(htmlspecialchars("@$nick"), $tmp[0]).$rest;
			}
			if(strlen($nick)===1){
				break;
			}
			$rest=mb_substr($nick, -1).$rest;
			$nick=mb_substr($nick, 0, -1);
		}
		return $matched[0];
	}, $message);
}

function add_message(string $message, string $recipient, string $poster, int $delstatus, int $poststatus, string $displaysend, string$style) : bool {
	global $db;
	if($message===''){
		return false;
	}
	$newmessage=[
		'postdate'	=>time(),
		'poststatus'	=>$poststatus,
		'poster'	=>$poster,
		'recipient'	=>$recipient,
		'text'		=>"<span class=\"usermsg\">$displaysend".style_this($message, $style).'</span>',
		'delstatus'	=>$delstatus
	];
	//prevent posting the same message twice, if no other message was posted in-between.
	$stmt=$db->prepare('SELECT id FROM ' . PREFIX . 'messages WHERE poststatus=? AND poster=? AND recipient=? AND text=? AND id IN (SELECT * FROM (SELECT id FROM ' . PREFIX . 'messages ORDER BY id DESC LIMIT 1) AS t);');
	$stmt->execute([$newmessage['poststatus'], $newmessage['poster'], $newmessage['recipient'], $newmessage['text']]);
	if($stmt->fetch(PDO::FETCH_NUM)){
		return false;
	}
	write_message($newmessage);
	return true;
}

function add_system_message(string $mes, string $doer): void
{
	if($mes===''){
		return;
	}
	if($doer==='' || !get_setting('namedoers')){
		$sysmessage=[
			'postdate'	=>time(),
			'poststatus'	=>4,
			'poster'	=>'',
			'recipient'	=>'',
			'text'		=>"$mes",
			'delstatus'	=>4
		];

	} else {
		$sysmessage=[
			'postdate'	=>time(),
			'poststatus'	=>4,
			'poster'	=>'',
			'recipient'	=>'',
			'text'		=>"$mes ($doer)",
			'delstatus'	=>4
		];
	}
	write_message($sysmessage);
}

function write_message(array $message): void
{
	global $db;
	if(MSGENCRYPTED){
		try {
			$message['text']=base64_encode(sodium_crypto_aead_aes256gcm_encrypt($message['text'], '', AES_IV, ENCRYPTKEY));
		} catch (SodiumException $e){
			send_error($e->getMessage());
		}
	}
	$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'messages (postdate, poststatus, poster, recipient, text, delstatus) VALUES (?, ?, ?, ?, ?, ?);');
	$stmt->execute([$message['postdate'], $message['poststatus'], $message['poster'], $message['recipient'], $message['text'], $message['delstatus']]);
	if($message['poststatus']<9 && get_setting('sendmail')){
		$subject='New Chat message';
		$headers='From: '.get_setting('mailsender')."\r\nX-Mailer: PHP/".phpversion()."\r\nContent-Type: text/html; charset=UTF-8\r\n";
		$body='<html><body style="background-color:#'.get_setting('colbg').';color:#'.get_setting('coltxt').";\">$message[text]</body></html>";
		mail(get_setting('mailreceiver'), $subject, $body, $headers);
	}
}

function clean_room(): void
{
	global $U, $db;
	$db->query('DELETE FROM ' . PREFIX . 'messages;');
	add_system_message(sprintf(get_setting('msgclean'), get_setting('chatname')), $U['nickname']);
}

function clean_selected(int $status, string $nick): void
{
	global $db;
	if(isset($_POST['mid'])){
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'messages WHERE id=? AND (poster=? OR recipient=? OR (poststatus<? AND delstatus<?));');
		foreach($_POST['mid'] as $mid){
			$stmt->execute([$mid, $nick, $nick, $status, $status]);
		}
	}
}

function clean_inbox_selected(): void
{
	global $U, $db;
	if(isset($_POST['mid'])){
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'inbox WHERE id=? AND recipient=?;');
		foreach($_POST['mid'] as $mid){
			$stmt->execute([$mid, $U['nickname']]);
		}
	}
}

function del_all_messages(string $nick, int $entry): void
{
	global $db, $U;
	$globally = (bool) get_setting('postbox_delete_globally');
	if($globally && $U['status'] > 4){
		$stmt = $db->prepare( 'DELETE FROM ' . PREFIX . 'messages;' );
		$stmt->execute();
	} else {
		if ( $nick === '' ) {
			$nick = $U[ 'nickname' ];
		}
		$stmt = $db->prepare( 'DELETE FROM ' . PREFIX . 'messages WHERE poster=? AND postdate>=?;' );
		$stmt->execute( [ $nick, $entry ] );
		$stmt = $db->prepare( 'DELETE FROM ' . PREFIX . 'inbox WHERE poster=? AND postdate>=?;' );
		$stmt->execute( [ $nick, $entry ] );
	}
}

function del_last_message(): void
{
	global $U, $db;
	if($U['status']>1){
		$entry=0;
	}else{
		$entry=$U['entry'];
	}
	$globally = (bool) get_setting('postbox_delete_globally');
	if($globally && $U['status'] > 4) {
		$stmt = $db->prepare( 'SELECT id FROM ' . PREFIX . 'messages WHERE postdate>=? ORDER BY id DESC LIMIT 1;' );
		$stmt->execute( [ $entry ] );
	} else {
		$stmt = $db->prepare( 'SELECT id FROM ' . PREFIX . 'messages WHERE poster=? AND postdate>=? ORDER BY id DESC LIMIT 1;' );
		$stmt->execute( [ $U[ 'nickname' ], $entry ] );
	}
	if ( $id = $stmt->fetch( PDO::FETCH_NUM ) ) {
		$stmt = $db->prepare( 'DELETE FROM ' . PREFIX . 'messages WHERE id=?;' );
		$stmt->execute( $id );
		$stmt = $db->prepare( 'DELETE FROM ' . PREFIX . 'inbox WHERE postid=?;' );
		$stmt->execute( $id );
	}
}

function print_messages(int $delstatus=0): void
{
	global $U, $db;
	$dateformat=get_setting('dateformat');
	if(!$U['embed'] && get_setting('imgembed')){
		$removeEmbed=true;
	}else{
		$removeEmbed=false;
	}
	if($U['timestamps'] && !empty($dateformat)){
		$timestamps=true;
	}else{
		$timestamps=false;
	}
	if($U['sortupdown']){
		$direction='ASC';
	}else{
		$direction='DESC';
	}
	if($U['status']>1){
		$entry=0;
	}else{
		$entry=$U['entry'];
	}
	echo '<div id="messages">';
	if($delstatus>0){
		$stmt=$db->prepare('SELECT postdate, id, text FROM ' . PREFIX . 'messages WHERE '.
		"(poststatus<? AND delstatus<?) OR ((poster=? OR recipient=?) AND postdate>=?) ORDER BY id $direction;");
		$stmt->execute([$U['status'], $delstatus, $U['nickname'], $U['nickname'], $entry]);
		while($message=$stmt->fetch(PDO::FETCH_ASSOC)){
			prepare_message_print($message, $removeEmbed);
			echo "<div class=\"msg\"><label><input type=\"checkbox\" name=\"mid[]\" value=\"$message[id]\">";
			if($timestamps){
				echo ' <small>'.date($dateformat, $message['postdate']).' - </small>';
			}
			echo " $message[text]</label></div>";
		}
	}else{
		$stmt=$db->prepare('SELECT id, postdate, poststatus, text FROM ' . PREFIX . 'messages WHERE (poststatus<=? OR poststatus=4 OR '.
		'(poststatus=9 AND ( (poster=? AND recipient NOT IN (SELECT ign FROM ' . PREFIX . 'ignored WHERE ignby=?) ) OR recipient=?) AND postdate>=?)'.
		') AND poster NOT IN (SELECT ign FROM ' . PREFIX . "ignored WHERE ignby=?) ORDER BY id $direction;");
		$stmt->execute([$U['status'], $U['nickname'], $U['nickname'], $U['nickname'], $entry, $U['nickname']]);
		while($message=$stmt->fetch(PDO::FETCH_ASSOC)){
			prepare_message_print($message, $removeEmbed);
			echo '<div class="msg">';
			if($timestamps){
				echo '<small>'.date($dateformat, $message['postdate']).' - </small>';
			}
			if ($message['poststatus']==4) {
				echo '<span class="sysmsg" title="'._('system message').'">'.get_setting('sysmessagetxt')."$message[text]</span></div>";
			} else {
				echo "$message[text]</div>";
			}
		}
	}
	echo '</div>';
}

function prepare_message_print(array &$message, bool $removeEmbed): void
{
	if(MSGENCRYPTED){
		try {
			$message['text']=sodium_crypto_aead_aes256gcm_decrypt(base64_decode($message['text']), null, AES_IV, ENCRYPTKEY);
		} catch (SodiumException $e){
			send_error($e->getMessage());
		}
	}
	if($removeEmbed){
		$message['text']=preg_replace_callback('/<img src="([^"]+)" rel="noreferrer" loading="lazy"><\/a>/u',
			function ($matched){
				return "$matched[1]</a>";
			}
		, $message['text']);
	}
}

// this and that

function send_headers(): void
{
	global $U, $scripts, $styles;
	header('Content-Type: text/html; charset=UTF-8');
	header('Pragma: no-cache');
	header('Cache-Control: no-cache, no-store, must-revalidate, max-age=0, private');
	header('Expires: 0');
	header('Referrer-Policy: no-referrer');
	header("Permissions-Policy: accelerometer=(), ambient-light-sensor=(), autoplay=(), battery=(), camera=(), cross-origin-isolated=(), display-capture=(), document-domain=(), encrypted-media=(), execution-while-not-rendered=(), execution-while-out-of-viewport=(), fullscreen=(), geolocation=(), gyroscope=(), magnetometer=(), microphone=(), midi=(), navigation-override=(), payment=(), picture-in-picture=(), publickey-credentials-get=(), screen-wake-lock=(), sync-xhr=(), usb=(), web-share=(), xr-spatial-tracking=(), clipboard-read=(), clipboard-write=(), gamepad=(), speaker-selection=(), conversion-measurement=(), focus-without-user-activation=(), hid=(), idle-detection=(), sync-script=(), vertical-scroll=(), serial=(), trust-token-redemption=(), interest-cohort=(), otp-credentials=()");
	if(!get_setting('imgembed') || !($U['embed'] ?? false)){
		header("Cross-Origin-Embedder-Policy: require-corp");
	}
	header("Cross-Origin-Opener-Policy: same-origin");
	header("Cross-Origin-Resource-Policy: same-origin");
	$style_hashes = '';
	foreach($styles as $style) {
		$style_hashes .= " 'sha256-".base64_encode(hash('sha256', $style, true))."'";
	}
	$script_hashes = '';
	foreach($scripts as $script) {
		$script_hashes .= " 'sha256-".base64_encode(hash('sha256', $script, true))."'";
	}
	header("Content-Security-Policy: base-uri 'self'; default-src 'none'; font-src 'self'; form-action 'self'; frame-ancestors 'self'; frame-src 'self'; img-src * data:; media-src * data:; style-src 'self' 'unsafe-inline';" . (empty($script_hashes) ? '' : " script-src $script_hashes;")); // $style_hashes"); //we can add computed hashes as soon as all inline css is moved to default css
	header('X-Content-Type-Options: nosniff');
	header('X-Frame-Options: sameorigin');
	header('X-XSS-Protection: 1; mode=block');
	if($_SERVER['REQUEST_METHOD'] === 'HEAD'){
		exit; // headers sent, no further processing needed
	}
}

function save_setup(array $C): void
{
	global $db;
	//sanity checks and escaping
	foreach($C['msg_settings'] as $setting => $title){
		$_POST[$setting]=htmlspecialchars($_POST[$setting]);
	}
	foreach($C['number_settings'] as $setting => $title){
		settype($_POST[$setting], 'int');
	}
	foreach($C['colour_settings'] as $setting => $title){
		if(preg_match('/^#([a-f0-9]{6})$/i', $_POST[$setting], $match)){
			$_POST[$setting]=$match[1];
		}else{
			unset($_POST[$setting]);
		}
	}
	settype($_POST['guestaccess'], 'int');
	if(!preg_match('/^[01234]$/', $_POST['guestaccess'])){
		unset($_POST['guestaccess']);
	}else{
		change_guest_access(intval($_POST['guestaccess']));
	}
	settype($_POST['englobalpass'], 'int');
	settype($_POST['captcha'], 'int');
	settype($_POST['dismemcaptcha'], 'int');
	settype($_POST['guestreg'], 'int');
	if(isset($_POST['defaulttz'])){
		$tzs=timezone_identifiers_list();
		if(!in_array($_POST['defaulttz'], $tzs)){
			unset($_POST['defualttz']);
		}
	}
	$_POST['rulestxt']=preg_replace("/(\r?\n|\r\n?)/u", '<br>', $_POST['rulestxt']);
	$_POST['chatname']=htmlspecialchars($_POST['chatname']);
	$_POST['redirect']=htmlspecialchars($_POST['redirect']);
	if($_POST['memberexpire']<5){
		$_POST['memberexpire']=5;
	}
	if($_POST['captchatime']<30){
		$_POST['memberexpire']=30;
	}
	$max_refresh_rate = (int) get_setting('max_refresh_rate');
	$min_refresh_rate = (int) get_setting('min_refresh_rate');
	if($_POST['defaultrefresh']<$min_refresh_rate){
		$_POST['defaultrefresh']=$min_refresh_rate;
	}elseif($_POST['defaultrefresh']>$max_refresh_rate){
		$_POST['defaultrefresh']=$max_refresh_rate;
	}
	if($_POST['maxname']<1){
		$_POST['maxname']=1;
	}elseif($_POST['maxname']>50){
		$_POST['maxname']=50;
	}
	if($_POST['maxmessage']<1){
		$_POST['maxmessage']=1;
	}elseif($_POST['maxmessage']>16000){
		$_POST['maxmessage']=16000;
	}
		if($_POST['numnotes']<1){
		$_POST['numnotes']=1;
	}
	if(!valid_regex($_POST['nickregex'])){
		unset($_POST['nickregex']);
	}
	if(!valid_regex($_POST['passregex'])){
		unset($_POST['passregex']);
	}
	//save values
	foreach($C['settings'] as $setting){
		if(isset($_POST[$setting])){
			update_setting($setting, $_POST[$setting]);
		}
	}
}

function change_guest_access(int $guest_access) : void {
	global $db;
	if($guest_access === 4){
		$db->exec('DELETE FROM ' . PREFIX . 'sessions WHERE status<7;');
	}elseif($guest_access === 0){
		$db->exec('DELETE FROM ' . PREFIX . 'sessions WHERE status<3;');
	}
}

function set_default_tz(): void
{
	global $U;
	if(isset($U['tz'])){
		date_default_timezone_set($U['tz']);
	}else{
		date_default_timezone_set(get_setting('defaulttz'));
	}
}

function valid_admin() : bool {
	global $U;
	parse_sessions();
	if(!isset($U['session']) && isset($_POST['nick']) && isset($_POST['pass'])){
		create_session(true, $_POST['nick'], $_POST['pass']);
	}
	if(isset($U['status'])){
		if($U['status']>=7){
			return true;
		}
		send_access_denied();
	}
	return false;
}

function valid_nick(string $nick) : bool{
	$len=mb_strlen($nick);
	if($len<1 || $len>get_setting('maxname')){
		return false;
	}
	return preg_match('/'.get_setting('nickregex').'/u', $nick);
}

function valid_pass(string $pass) : bool {
	if(mb_strlen($pass)<get_setting('minpass')){
		return false;
	}
	return preg_match('/'.get_setting('passregex').'/u', $pass);
}

function valid_regex(string &$regex) : bool {
	$regex=preg_replace('~(^|[^\\\\])/~', "$1\/u", $regex); // Escape "/" if not yet escaped
	return (@preg_match("/$_POST[match]/u", '') !== false);
}

function get_timeout(int $lastpost, int $expire): void
{
	$s=($lastpost+60*$expire)-time();
	$m=floor($s/60);
	$s%=60;
	if($s<10){
		$s="0$s";
	}
	if($m>60){
		$h=floor($m/60);
		$m%=60;
		if($m<10){
			$m="0$m";
		}
		echo "$h:$m:$s";
	}else{
		echo "$m:$s";
	}
}

function print_colours(): void
{
	// Prints a short list with selected named HTML colours and filters out illegible text colours for the given background.
	// It's a simple comparison of weighted grey values. This is not very accurate but gets the job done well enough.
	// name=>[colour, greyval(colour), translated name]
	$colours=[
		'Beige'=>['F5F5DC', 242.25, _('Beige')],
		'Black'=>['000000', 0, _('Black')],
		'Blue'=>['0000FF', 28.05, _('Blue')],
		'BlueViolet'=>['8A2BE2', 91.63, _('Blue violet')],
		'Brown'=>['A52A2A', 78.9, _('Brown')],
		'Cyan'=>['00FFFF', 178.5, _('Cyan')],
		'DarkBlue'=>['00008B', 15.29, _('Dark blue')],
		'DarkGreen'=>['006400', 59, _('Dark green')],
		'DarkRed'=>['8B0000', 41.7, _('Dark red')],
		'DarkViolet'=>['9400D3', 67.61, _('Dark violet')],
		'DeepSkyBlue'=>['00BFFF', 140.74, _('Sky blue')],
		'Gold'=>['FFD700', 203.35, _('Gold')],
		'Grey'=>['808080', 128, _('Grey')],
		'Green'=>['008000', 75.52, _('Green')],
		'HotPink'=>['FF69B4', 158.25, _('Hot pink')],
		'Indigo'=>['4B0082', 36.8, _('Indigo')],
		'LightBlue'=>['ADD8E6', 204.64, _('Light blue')],
		'LightGreen'=>['90EE90', 199.46, _('Light green')],
		'LimeGreen'=>['32CD32', 141.45, _('Lime green')],
		'Magenta'=>['FF00FF', 104.55, _('Magenta')],
		'Olive'=>['808000', 113.92, _('Olive')],
		'Orange'=>['FFA500', 173.85, _('Orange')],
		'OrangeRed'=>['FF4500', 117.21, _('Orange red')],
		'Purple'=>['800080', 52.48, _('Purple')],
		'Red'=>['FF0000', 76.5, _('Red')],
		'RoyalBlue'=>['4169E1', 106.2, _('Royal blue')],
		'SeaGreen'=>['2E8B57', 105.38, _('Sea green')],
		'Sienna'=>['A0522D', 101.33, _('Sienna')],
		'Silver'=>['C0C0C0', 192, _('Silver')],
		'Tan'=>['D2B48C', 184.6, _('Tan')],
		'Teal'=>['008080', 89.6, _('Teal')],
		'Violet'=>['EE82EE', 174.28, _('Violet')],
		'White'=>['FFFFFF', 255, _('White')],
		'Yellow'=>['FFFF00', 226.95, _('Yellow')],
		'YellowGreen'=>['9ACD32', 172.65, _('Yellow green')],
	];
	$greybg=greyval(get_setting('colbg'));
	foreach($colours as $name=>$colour){
		if(abs($greybg-$colour[1])>75){
			echo "<option value=\"$colour[0]\" style=\"color:#$colour[0];\">$colour[2]</option>";
		}
	}
}

function greyval(string $colour) : string {
	return hexdec(substr($colour, 0, 2))*.3+hexdec(substr($colour, 2, 2))*.59+hexdec(substr($colour, 4, 2))*.11;
}

function style_this(string $text, string $styleinfo) : string {
	return "<span style=\"$styleinfo\">$text</span>";
}

function check_init() : bool {
	global $db;
	try {
		$db->query( 'SELECT null FROM ' . PREFIX . 'settings LIMIT 1;' );
	} catch (Exception $e){
		return false;
	}
	return true;
}

// run every minute doing various database cleanup task
function cron(): void
{
	global $db;
	$time=time();
	if(get_setting('nextcron')>$time){
		return;
	}
	update_setting('nextcron', $time+10);
	// delete old sessions
	$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'sessions WHERE (status<=2 AND lastpost<(?-60*(SELECT value FROM ' . PREFIX . "settings WHERE setting='guestexpire'))) OR (status>2 AND lastpost<(?-60*(SELECT value FROM " . PREFIX . "settings WHERE setting='memberexpire')));");
	$stmt->execute([$time, $time]);
	// delete old messages
	$limit=get_setting('messagelimit');
	$stmt=$db->query('SELECT id FROM ' . PREFIX . "messages WHERE poststatus=1 OR poststatus=4 ORDER BY id DESC LIMIT 1 OFFSET $limit;");
	if($id=$stmt->fetch(PDO::FETCH_NUM)){
		$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'messages WHERE id<=?;');
		$stmt->execute($id);
	}
	$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'messages WHERE id IN (SELECT * FROM (SELECT id FROM ' . PREFIX . 'messages WHERE postdate<(?-60*(SELECT value FROM ' . PREFIX . "settings WHERE setting='messageexpire'))) AS t);");
	$stmt->execute([$time]);
	// delete expired ignored people
	$result=$db->query('SELECT id FROM ' . PREFIX . 'ignored WHERE ign NOT IN (SELECT nickname FROM ' . PREFIX . 'sessions UNION SELECT nickname FROM ' . PREFIX . 'members UNION SELECT poster FROM ' . PREFIX . 'messages) OR ignby NOT IN (SELECT nickname FROM ' . PREFIX . 'sessions UNION SELECT nickname FROM ' . PREFIX . 'members UNION SELECT poster FROM ' . PREFIX . 'messages);');
	$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'ignored WHERE id=?;');
	while($tmp=$result->fetch(PDO::FETCH_NUM)){
		$stmt->execute($tmp);
	}
	// delete files that do not belong to any message
	$result=$db->query('SELECT id FROM ' . PREFIX . 'files WHERE postid NOT IN (SELECT id FROM ' . PREFIX . 'messages UNION SELECT postid FROM ' . PREFIX . 'inbox);');
	$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'files WHERE id=?;');
	while($tmp=$result->fetch(PDO::FETCH_NUM)){
		$stmt->execute($tmp);
	}
	// delete old notes
	$limit=get_setting('numnotes');
	$to_keep = [];
	$stmt = $db->query('SELECT id FROM ' . PREFIX . "notes WHERE type=0 ORDER BY id DESC LIMIT $limit;");
	while($tmp = $stmt->fetch(PDO::FETCH_ASSOC)){
		$to_keep []= $tmp['id'];
	}
	$stmt = $db->query('SELECT id FROM ' . PREFIX . "notes WHERE type=1 ORDER BY id DESC LIMIT $limit;");
	while($tmp = $stmt->fetch(PDO::FETCH_ASSOC)){
		$to_keep []= $tmp['id'];
	}
	$query = 'DELETE FROM ' . PREFIX . 'notes WHERE type!=2 AND type!=3';
	if(!empty($to_keep)){
		$query .= ' AND id NOT IN (';
		for($i = count($to_keep); $i > 1; --$i){
			$query .= '?, ';
		}
		$query .= '?)';
	}
	$stmt = $db->prepare($query);
	$stmt->execute($to_keep);
	$result=$db->query('SELECT editedby, COUNT(*) AS cnt FROM ' . PREFIX . "notes WHERE type=2 GROUP BY editedby HAVING cnt>$limit;");
	$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'notes WHERE (type=2 OR type=3) AND editedby=? AND id NOT IN (SELECT * FROM (SELECT id FROM ' . PREFIX . "notes WHERE (type=2 OR type=3) AND editedby=? ORDER BY id DESC LIMIT $limit) AS t);");
	while($tmp=$result->fetch(PDO::FETCH_NUM)){
		$stmt->execute([$tmp[0], $tmp[0]]);
	}
	// delete old captchas
	$stmt=$db->prepare('DELETE FROM ' . PREFIX . 'captcha WHERE time<(?-(SELECT value FROM ' . PREFIX . "settings WHERE setting='captchatime'));");
	$stmt->execute([$time]);
	// delete member associated data of deleted accounts
	$db->query('DELETE FROM ' . PREFIX . 'inbox WHERE recipient NOT IN (SELECT nickname FROM ' . PREFIX . 'members);');
	$db->query('DELETE FROM ' . PREFIX . 'notes WHERE (type=2 OR type=3) AND editedby NOT IN (SELECT nickname FROM ' . PREFIX . 'members);');
}

function destroy_chat(array $C): void
{
	global $db, $memcached, $session;
	setcookie(COOKIENAME, false);
	$session = '';
	print_start('destroy');
	$db->exec('DROP TABLE ' . PREFIX . 'captcha;');
	$db->exec('DROP TABLE ' . PREFIX . 'files;');
	$db->exec('DROP TABLE ' . PREFIX . 'filter;');
	$db->exec('DROP TABLE ' . PREFIX . 'ignored;');
	$db->exec('DROP TABLE ' . PREFIX . 'inbox;');
	$db->exec('DROP TABLE ' . PREFIX . 'linkfilter;');
	$db->exec('DROP TABLE ' . PREFIX . 'members;');
	$db->exec('DROP TABLE ' . PREFIX . 'messages;');
	$db->exec('DROP TABLE ' . PREFIX . 'notes;');
	$db->exec('DROP TABLE ' . PREFIX . 'sessions;');
	$db->exec('DROP TABLE ' . PREFIX . 'settings;');
	if(MEMCACHED){
		$memcached->delete(DBNAME . '-' . PREFIX . 'filter');
		$memcached->delete(DBNAME . '-' . PREFIX . 'linkfilter');
		foreach($C['settings'] as $setting){
			$memcached->delete(DBNAME . '-' . PREFIX . "settings-$setting");
		}
		$memcached->delete(DBNAME . '-' . PREFIX . 'settings-dbversion');
		$memcached->delete(DBNAME . '-' . PREFIX . 'settings-msgencrypted');
		$memcached->delete(DBNAME . '-' . PREFIX . 'settings-nextcron');
	}
	echo '<h2>'._('Successfully destroyed chat').'</h2><br><br><br>';
	echo form('setup').submit(_('Initial Setup')).'</form>'.credit();
	print_end();
}

function init_chat(): void
{
	global $db;
	if(check_init()){
		$suwrite=_('Database tables already exist! To continue, you have to delete these tables manually first.');
		$result=$db->query('SELECT null FROM ' . PREFIX . 'members WHERE status=8;');
		if($result->fetch(PDO::FETCH_NUM)){
			$suwrite=_('A Superadmin already exists!');
		}
	}elseif(!preg_match('/^[a-z0-9]{1,20}$/i', $_POST['sunick'])){
		$suwrite=sprintf(_('Invalid nickname (%1$d characters maximum and has to match the regular expression "%2$s")'), 20, '^[A-Za-z1-9]*$');
	}elseif(mb_strlen($_POST['supass'])<5){
		$suwrite=sprintf(_('Invalid password (At least %1$d characters and has to match the regular expression "%2$s")'), 5, '.*');
	}elseif($_POST['supass']!==$_POST['supassc']){
		$suwrite=_('Password confirmation does not match!');
	}else{
		ignore_user_abort(true);
		set_time_limit(0);
		if(DBDRIVER===0){//MySQL
			$memengine=' ENGINE=MEMORY';
			$diskengine=' ENGINE=InnoDB';
			$charset=' DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin';
			$primary='integer PRIMARY KEY AUTO_INCREMENT';
			$longtext='longtext';
		}elseif(DBDRIVER===1){//PostgreSQL
			$memengine='';
			$diskengine='';
			$charset='';
			$primary='serial PRIMARY KEY';
			$longtext='text';
		}else{//SQLite
			$memengine='';
			$diskengine='';
			$charset='';
			$primary='integer PRIMARY KEY';
			$longtext='text';
		}
		$db->exec('CREATE TABLE ' . PREFIX . "captcha (id $primary, time integer NOT NULL, code char(5) NOT NULL)$memengine$charset;");
		$db->exec('CREATE TABLE ' . PREFIX . "files (id $primary, postid integer NOT NULL UNIQUE, filename varchar(255) NOT NULL, hash char(40) NOT NULL, type varchar(255) NOT NULL, data $longtext NOT NULL)$diskengine$charset;");
		$db->exec('CREATE INDEX ' . PREFIX . 'files_hash ON ' . PREFIX . 'files(hash);');
		$db->exec('CREATE TABLE ' . PREFIX . "filter (id $primary, filtermatch varchar(255) NOT NULL, filterreplace text NOT NULL, allowinpm smallint NOT NULL, regex smallint NOT NULL, kick smallint NOT NULL, cs smallint NOT NULL)$diskengine$charset;");
		$db->exec('CREATE TABLE ' . PREFIX . "ignored (id $primary, ign varchar(50) NOT NULL, ignby varchar(50) NOT NULL)$diskengine$charset;");
		$db->exec('CREATE INDEX ' . PREFIX . 'ign ON ' . PREFIX . 'ignored(ign);');
		$db->exec('CREATE INDEX ' . PREFIX . 'ignby ON ' . PREFIX . 'ignored(ignby);');
		$db->exec('CREATE TABLE ' . PREFIX . "members (id $primary, nickname varchar(50) NOT NULL UNIQUE, passhash varchar(255) NOT NULL, status smallint NOT NULL, refresh smallint NOT NULL, bgcolour char(6) NOT NULL, regedby varchar(50) DEFAULT '', lastlogin integer DEFAULT 0, loginfails integer unsigned NOT NULL DEFAULT 0, timestamps smallint NOT NULL, embed smallint NOT NULL, incognito smallint NOT NULL, style varchar(255) NOT NULL, nocache smallint NOT NULL, tz varchar(255) NOT NULL, eninbox smallint NOT NULL, sortupdown smallint NOT NULL, hidechatters smallint NOT NULL, nocache_old smallint NOT NULL)$diskengine$charset;");
		$db->exec('CREATE TABLE ' . PREFIX . "inbox (id $primary, postdate integer NOT NULL, postid integer NOT NULL UNIQUE, poster varchar(50) NOT NULL, recipient varchar(50) NOT NULL, text text NOT NULL, FOREIGN KEY (recipient) REFERENCES " . PREFIX . "members(nickname) ON DELETE CASCADE ON UPDATE CASCADE)$diskengine$charset;");
		$db->exec('CREATE INDEX ' . PREFIX . 'inbox_poster ON ' . PREFIX . 'inbox(poster);');
		$db->exec('CREATE INDEX ' . PREFIX . 'inbox_recipient ON ' . PREFIX . 'inbox(recipient);');
		$db->exec('CREATE TABLE ' . PREFIX . "linkfilter (id $primary, filtermatch varchar(255) NOT NULL, filterreplace varchar(255) NOT NULL, regex smallint NOT NULL)$diskengine$charset;");
		$db->exec('CREATE TABLE ' . PREFIX . "messages (id $primary, postdate integer NOT NULL, poststatus smallint NOT NULL, poster varchar(50) NOT NULL, recipient varchar(50) NOT NULL, text text NOT NULL, delstatus smallint NOT NULL)$diskengine$charset;");
		$db->exec('CREATE INDEX ' . PREFIX . 'poster ON ' . PREFIX . 'messages (poster);');
		$db->exec('CREATE INDEX ' . PREFIX . 'recipient ON ' . PREFIX . 'messages(recipient);');
		$db->exec('CREATE INDEX ' . PREFIX . 'postdate ON ' . PREFIX . 'messages(postdate);');
		$db->exec('CREATE INDEX ' . PREFIX . 'poststatus ON ' . PREFIX . 'messages(poststatus);');
		$db->exec('CREATE TABLE ' . PREFIX . "notes (id $primary, type smallint NOT NULL, lastedited integer NOT NULL, editedby varchar(50) NOT NULL, text text NOT NULL)$diskengine$charset;");
		$db->exec('CREATE INDEX ' . PREFIX . 'notes_type ON ' . PREFIX . 'notes(type);');
		$db->exec('CREATE INDEX ' . PREFIX . 'notes_editedby ON ' . PREFIX . 'notes(editedby);');
		$db->exec('CREATE TABLE ' . PREFIX . "sessions (id $primary, session char(32) NOT NULL UNIQUE, nickname varchar(50) NOT NULL UNIQUE, status smallint NOT NULL, refresh smallint NOT NULL, style varchar(255) NOT NULL, lastpost integer NOT NULL, passhash varchar(255) NOT NULL, postid char(6) NOT NULL DEFAULT '000000', useragent varchar(255) NOT NULL, kickmessage varchar(255) DEFAULT '', bgcolour char(6) NOT NULL, entry integer NOT NULL, timestamps smallint NOT NULL, embed smallint NOT NULL, incognito smallint NOT NULL, ip varchar(45) NOT NULL, nocache smallint NOT NULL, tz varchar(255) NOT NULL, eninbox smallint NOT NULL, sortupdown smallint NOT NULL, hidechatters smallint NOT NULL, nocache_old smallint NOT NULL)$memengine$charset;");
		$db->exec('CREATE INDEX ' . PREFIX . 'status ON ' . PREFIX . 'sessions(status);');
		$db->exec('CREATE INDEX ' . PREFIX . 'lastpost ON ' . PREFIX . 'sessions(lastpost);');
		$db->exec('CREATE INDEX ' . PREFIX . 'incognito ON ' . PREFIX . 'sessions(incognito);');
		$db->exec('CREATE TABLE ' . PREFIX . "settings (setting varchar(50) NOT NULL PRIMARY KEY, value text NOT NULL)$diskengine$charset;");

		$settings=[
			['guestaccess', '0'],
			['globalpass', ''],
			['englobalpass', '0'],
			['captcha', '0'],
			['dateformat', 'm-d H:i:s'],
			['rulestxt', ''],
			['msgencrypted', '0'],
			['dbversion', DBVERSION],
			['css', ''],
			['memberexpire', '60'],
			['guestexpire', '15'],
			['kickpenalty', '10'],
			['entrywait', '120'],
			['messageexpire', '14400'],
			['messagelimit', '150'],
			['maxmessage', 2000],
			['captchatime', '600'],
			['colbg', '000000'],
			['coltxt', 'FFFFFF'],
			['maxname', '20'],
			['minpass', '5'],
			['defaultrefresh', '20'],
			['dismemcaptcha', '0'],
			['suguests', '0'],
			['imgembed', '1'],
			['timestamps', '1'],
			['trackip', '0'],
			['captchachars', '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'],
			['memkick', '1'],
			['memkickalways', '0'],
			['namedoers', '1'],
			['forceredirect', '0'],
			['redirect', ''],
			['incognito', '1'],
			['chatname', 'My Chat'],
			['topic', ''],
			['msgsendall', _('%s - ')],
			['msgsendmem', _('[M] %s - ')],
			['msgsendmod', _('[Staff] %s - ')],
			['msgsendadm', _('[Admin] %s - ')],
			['msgsendprv', _('[%1$s to %2$s] - ')],
			['msgenter', _('%s entered the chat.')],
			['msgexit', _('%s left the chat.')],
			['msgmemreg', _('%s is now a registered member.')],
			['msgsureg', _('%s is now a registered applicant.')],
			['msgkick', _('%s has been kicked.')],
			['msgmultikick', _('%s have been kicked.')],
			['msgallkick', _('All guests have been kicked.')],
			['msgclean', _('%s has been cleaned.')],
			['numnotes', '3'],
			['mailsender', 'www-data <www-data@localhost>'],
			['mailreceiver', 'Webmaster <webmaster@localhost>'],
			['sendmail', '0'],
			['modfallback', '1'],
			['guestreg', '0'],
			['disablepm', '0'],
			['disabletext', '<h1>'._('Temporarily disabled').'</h1>'],
			['defaulttz', 'UTC'],
			['eninbox', '0'],
			['passregex', '.*'],
			['nickregex', '^[A-Za-z0-9]*$'],
			['externalcss', ''],
			['enablegreeting', '0'],
			['sortupdown', '0'],
			['hidechatters', '0'],
			['enfileupload', '0'],
			['msgattache', '%2$s [%1$s]'],
			['maxuploadsize', '1024'],
			['nextcron', '0'],
			['personalnotes', '1'],
			['publicnotes', '1'],
			['filtermodkick', '0'],
			['metadescription', _('A chat community')],
			['sysmessagetxt', 'ℹ️ &nbsp;'],
			['hide_reload_post_box', '0'],
			['hide_reload_messages', '0'],
			['hide_profile', '0'],
			['hide_admin', '0'],
			['hide_notes', '0'],
			['hide_clone', '0'],
			['hide_rearrange', '0'],
			['hide_help', '0'],
			['max_refresh_rate', '150'],
			['min_refresh_rate', '5'],
			['postbox_delete_globally', '0'],
			['allow_js', '1'],
		];
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'settings (setting, value) VALUES (?, ?);');
		foreach($settings as $pair){
			$stmt->execute($pair);
		}
		$reg=[
			'nickname'	=>$_POST['sunick'],
			'passhash'	=>password_hash($_POST['supass'], PASSWORD_DEFAULT),
			'status'	=>8,
			'refresh'	=>20,
			'bgcolour'	=>'000000',
			'timestamps'	=>1,
			'style'		=>'color:#FFFFFF;',
			'embed'		=>1,
			'incognito'	=>0,
			'nocache'	=>0,
			'nocache_old'	=>1,
			'tz'		=>'UTC',
			'eninbox'	=>0,
			'sortupdown'	=>0,
			'hidechatters'	=>0,
		];
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'members (nickname, passhash, status, refresh, bgcolour, timestamps, style, embed, incognito, nocache, tz, eninbox, sortupdown, hidechatters, nocache_old) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);');
		$stmt->execute([$reg['nickname'], $reg['passhash'], $reg['status'], $reg['refresh'], $reg['bgcolour'], $reg['timestamps'], $reg['style'], $reg['embed'], $reg['incognito'], $reg['nocache'], $reg['tz'], $reg['eninbox'], $reg['sortupdown'], $reg['hidechatters'], $reg['nocache_old']]);
		$suwrite=_('Successfully registered!');
	}
	print_start('init');
	echo '<h2>'._('Initial Setup').'</h2><br><h3>'._('Superadmin Login')."</h3>$suwrite<br><br><br>";
	echo form('setup').submit(_('Go to the Setup-Page')).'</form>'.credit();
	print_end();
}

function update_db(): void
{
	global $db, $memcached;
	$dbversion=(int) get_setting('dbversion');
	$msgencrypted=(bool) get_setting('msgencrypted');
	if($dbversion>=DBVERSION && $msgencrypted===MSGENCRYPTED){
		return;
	}
	ignore_user_abort(true);
	set_time_limit(0);
	if(DBDRIVER===0){//MySQL
		$memengine=' ENGINE=MEMORY';
		$diskengine=' ENGINE=InnoDB';
		$charset=' DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin';
		$primary='integer PRIMARY KEY AUTO_INCREMENT';
		$longtext='longtext';
	}elseif(DBDRIVER===1){//PostgreSQL
		$memengine='';
		$diskengine='';
		$charset='';
		$primary='serial PRIMARY KEY';
		$longtext='text';
	}else{//SQLite
		$memengine='';
		$diskengine='';
		$charset='';
		$primary='integer PRIMARY KEY';
		$longtext='text';
	}
	$msg='';
	if($dbversion<2){
		$db->exec('CREATE TABLE IF NOT EXISTS ' . PREFIX . "ignored (id integer unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT, ignored varchar(50) NOT NULL, `by` varchar(50) NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8;");
	}
	if($dbversion<3){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('rulestxt', '');");
	}
	if($dbversion<4){
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD incognito smallint NOT NULL;');
	}
	if($dbversion<5){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('globalpass', '');");
	}
	if($dbversion<6){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('dateformat', 'm-d H:i:s');");
	}
	if($dbversion<7){
		$db->exec('ALTER TABLE ' . PREFIX . 'captcha ADD code char(5) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL;');
	}
	if($dbversion<8){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('captcha', '0'), ('englobalpass', '0');");
		$ga=(int) get_setting('guestaccess');
		if($ga===-1){
			update_setting('guestaccess', 0);
			update_setting('englobalpass', 1);
		}elseif($ga===4){
			update_setting('guestaccess', 1);
			update_setting('englobalpass', 2);
		}
	}
	if($dbversion<9){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting,value) VALUES ('msgencrypted', '0');");
		$db->exec('ALTER TABLE ' . PREFIX . 'settings MODIFY value varchar(20000) NOT NULL;');
		$db->exec('ALTER TABLE ' . PREFIX . 'messages DROP postid;');
	}
	if($dbversion<10){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('css', ''), ('memberexpire', '60'), ('guestexpire', '15'), ('kickpenalty', '10'), ('entrywait', '120'), ('messageexpire', '14400'), ('messagelimit', '150'), ('maxmessage', 2000), ('captchatime', '600');");
	}
	if($dbversion<11){
		$db->exec('ALTER TABLE ' , PREFIX . 'captcha CHARACTER SET utf8 COLLATE utf8_bin;');
		$db->exec('ALTER TABLE ' . PREFIX . 'filter CHARACTER SET utf8 COLLATE utf8_bin;');
		$db->exec('ALTER TABLE ' . PREFIX . 'ignored CHARACTER SET utf8 COLLATE utf8_bin;');
		$db->exec('ALTER TABLE ' . PREFIX . 'messages CHARACTER SET utf8 COLLATE utf8_bin;');
		$db->exec('ALTER TABLE ' . PREFIX . 'notes CHARACTER SET utf8 COLLATE utf8_bin;');
		$db->exec('ALTER TABLE ' . PREFIX . 'settings CHARACTER SET utf8 COLLATE utf8_bin;');
		$db->exec('CREATE TABLE ' . PREFIX . "linkfilter (id integer unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT, `match` varchar(255) NOT NULL, `replace` varchar(255) NOT NULL, regex smallint NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE utf8_bin;");
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD style varchar(255) NOT NULL;');
		$result=$db->query('SELECT * FROM ' . PREFIX . 'members;');
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'members SET style=? WHERE id=?;');
		$F=load_fonts();
		while($temp=$result->fetch(PDO::FETCH_ASSOC)){
			$style="color:#$temp[colour];";
			if(isset($F[$temp['fontface']])){
				$style.=$F[$temp['fontface']];
			}
			if(strpos($temp['fonttags'], 'i')!==false){
				$style.='font-style:italic;';
			}
			if(strpos($temp['fonttags'], 'b')!==false){
				$style.='font-weight:bold;';
			}
			$stmt->execute([$style, $temp['id']]);
		}
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('colbg', '000000'), ('coltxt', 'FFFFFF'), ('maxname', '20'), ('minpass', '5'), ('defaultrefresh', '20'), ('dismemcaptcha', '0'), ('suguests', '0'), ('imgembed', '1'), ('timestamps', '1'), ('trackip', '0'), ('captchachars', '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'), ('memkick', '1'), ('forceredirect', '0'), ('redirect', ''), ('incognito', '1');");
	}
	if($dbversion<12){
		$db->exec('ALTER TABLE ' . PREFIX . 'captcha MODIFY code char(5) NOT NULL, DROP INDEX id, ADD PRIMARY KEY (id) USING BTREE;');
		$db->exec('ALTER TABLE ' . PREFIX . 'captcha ENGINE=MEMORY;');
		$db->exec('ALTER TABLE ' . PREFIX . 'filter MODIFY id integer unsigned NOT NULL AUTO_INCREMENT, MODIFY `match` varchar(255) NOT NULL, MODIFY replace varchar(20000) NOT NULL;');
		$db->exec('ALTER TABLE ' . PREFIX . 'ignored MODIFY ignored varchar(50) NOT NULL, MODIFY `by` varchar(50) NOT NULL, ADD INDEX(ignored), ADD INDEX(`by`);');
		$db->exec('ALTER TABLE ' . PREFIX . 'linkfilter MODIFY match varchar(255) NOT NULL, MODIFY replace varchar(255) NOT NULL;');
		$db->exec('ALTER TABLE ' . PREFIX . 'messages MODIFY poster varchar(50) NOT NULL, MODIFY recipient varchar(50) NOT NULL, MODIFY text varchar(20000) NOT NULL, ADD INDEX(poster), ADD INDEX(recipient), ADD INDEX(postdate), ADD INDEX(poststatus);');
		$db->exec('ALTER TABLE ' . PREFIX . 'notes MODIFY type char(5) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL, MODIFY editedby varchar(50) NOT NULL, MODIFY text varchar(20000) NOT NULL;');
		$db->exec('ALTER TABLE ' . PREFIX . 'settings MODIFY id integer unsigned NOT NULL, MODIFY setting varchar(50) CHARACTER SET latin1 COLLATE latin1_bin NOT NULL, MODIFY value varchar(20000) NOT NULL;');
		$db->exec('ALTER TABLE ' . PREFIX . 'settings DROP PRIMARY KEY, DROP id, ADD PRIMARY KEY(setting);');
		$stmt = $db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('chatname', 'My Chat'), ('topic', ''), ('msgsendall', ?), ('msgsendmem', ?), ('msgsendmod', ?), ('msgsendadm', ?), ('msgsendprv', ?), ('numnotes', '3');");
		$stmt->execute([_('%s - '), _('[M] %s - '), _('[Staff] %s - '), _('[Admin] %s - '), _('[%1$s to %2$s] - ')]);
	}
	if($dbversion<13){
		$db->exec('ALTER TABLE ' . PREFIX . 'filter CHANGE `match` filtermatch varchar(255) NOT NULL, CHANGE `replace` filterreplace varchar(20000) NOT NULL;');
		$db->exec('ALTER TABLE ' . PREFIX . 'ignored CHANGE ignored ign varchar(50) NOT NULL, CHANGE `by` ignby varchar(50) NOT NULL;');
		$db->exec('ALTER TABLE ' . PREFIX . 'linkfilter CHANGE `match` filtermatch varchar(255) NOT NULL, CHANGE `replace` filterreplace varchar(255) NOT NULL;');
	}
	if($dbversion<14){
		if(MEMCACHED){
			$memcached->delete(DBNAME . '-' . PREFIX . 'members');
			$memcached->delete(DBNAME . '-' . PREFIX . 'ignored');
		}
		if(DBDRIVER===0){//MySQL - previously had a wrong SQL syntax and the captcha table was not created.
			$db->exec('CREATE TABLE IF NOT EXISTS ' . PREFIX . 'captcha (id integer unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT, time integer unsigned NOT NULL, code char(5) NOT NULL) ENGINE=MEMORY DEFAULT CHARSET=utf8 COLLATE=utf8_bin;');
		}
	}
	if($dbversion<15){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('mailsender', 'www-data <www-data@localhost>'), ('mailreceiver', 'Webmaster <webmaster@localhost>'), ('sendmail', '0'), ('modfallback', '1'), ('guestreg', '0');");
	}
	if($dbversion<17){
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD COLUMN nocache smallint NOT NULL DEFAULT 0;');
	}
	if($dbversion<18){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('disablepm', '0');");
	}
	if($dbversion<19){
		$stmt = $db->prepare('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('disabletext', ?);");
		$stmt->execute(['<h1>'._('Temporarily disabled').'</h1>']);
	}
	if($dbversion<20){
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD COLUMN tz smallint NOT NULL DEFAULT 0;');
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('defaulttz', 'UTC');");
	}
	if($dbversion<21){
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD COLUMN eninbox smallint NOT NULL DEFAULT 0;');
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('eninbox', '0');");
		if(DBDRIVER===0){
			$db->exec('CREATE TABLE ' . PREFIX . "inbox (id integer unsigned NOT NULL PRIMARY KEY AUTO_INCREMENT, postid integer unsigned NOT NULL, postdate integer unsigned NOT NULL, poster varchar(50) NOT NULL, recipient varchar(50) NOT NULL, text varchar(20000) NOT NULL, INDEX(postid), INDEX(poster), INDEX(recipient)) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin;");
		}else{
			$db->exec('CREATE TABLE ' . PREFIX . "inbox (id $primary, postdate integer NOT NULL, postid integer NOT NULL, poster varchar(50) NOT NULL, recipient varchar(50) NOT NULL, text varchar(20000) NOT NULL);");
			$db->exec('CREATE INDEX ' . PREFIX . 'inbox_postid ON ' . PREFIX . 'inbox(postid);');
			$db->exec('CREATE INDEX ' . PREFIX . 'inbox_poster ON ' . PREFIX . 'inbox(poster);');
			$db->exec('CREATE INDEX ' . PREFIX . 'inbox_recipient ON ' . PREFIX . 'inbox(recipient);');
		}
	}
	if($dbversion<23){
		$db->exec('DELETE FROM ' . PREFIX . "settings WHERE setting='enablejs';");
	}
	if($dbversion<25){
		$db->exec('DELETE FROM ' . PREFIX . "settings WHERE setting='keeplimit';");
	}
	if($dbversion<26){
		$db->exec('INSERT INTO ' . PREFIX . 'settings (setting, value) VALUES (\'passregex\', \'.*\'), (\'nickregex\', \'^[A-Za-z0-9]*$\');');
	}
	if($dbversion<27){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('externalcss', '');");
	}
	if($dbversion<28){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('enablegreeting', '0');");
	}
	if($dbversion<29){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('sortupdown', '0');");
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD COLUMN sortupdown smallint NOT NULL DEFAULT 0;');
	}
	if($dbversion<30){
		$db->exec('ALTER TABLE ' . PREFIX . 'filter ADD COLUMN cs smallint NOT NULL DEFAULT 0;');
		if(MEMCACHED){
			$memcached->delete(DBNAME . '-' . PREFIX . "filter");
		}
	}
	if($dbversion<31){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('hidechatters', '0');");
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD COLUMN hidechatters smallint NOT NULL DEFAULT 0;');
	}
	if($dbversion<32 && DBDRIVER===0){
		//recreate db in utf8mb4
		try{
			$olddb=new PDO('mysql:host=' . DBHOST . ';dbname=' . DBNAME, DBUSER, DBPASS, [PDO::ATTR_ERRMODE=>PDO::ERRMODE_WARNING, PDO::ATTR_PERSISTENT=>PERSISTENT]);
			$db->exec('DROP TABLE ' . PREFIX . 'captcha;');
			$db->exec('CREATE TABLE ' . PREFIX . "captcha (id integer PRIMARY KEY AUTO_INCREMENT, time integer NOT NULL, code char(5) NOT NULL) ENGINE=MEMORY DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$result=$olddb->query('SELECT filtermatch, filterreplace, allowinpm, regex, kick, cs FROM ' . PREFIX . 'filter;');
			$data=$result->fetchAll(PDO::FETCH_NUM);
			$db->exec('DROP TABLE ' . PREFIX . 'filter;');
			$db->exec('CREATE TABLE ' . PREFIX . "filter (id integer PRIMARY KEY AUTO_INCREMENT, filtermatch varchar(255) NOT NULL, filterreplace text NOT NULL, allowinpm smallint NOT NULL, regex smallint NOT NULL, kick smallint NOT NULL, cs smallint NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'filter (filtermatch, filterreplace, allowinpm, regex, kick, cs) VALUES(?, ?, ?, ?, ?, ?);');
			foreach($data as $tmp){
				$stmt->execute($tmp);
			}
			$result=$olddb->query('SELECT ign, ignby FROM ' . PREFIX . 'ignored;');
			$data=$result->fetchAll(PDO::FETCH_NUM);
			$db->exec('DROP TABLE ' . PREFIX . 'ignored;');
			$db->exec('CREATE TABLE ' . PREFIX . "ignored (id integer PRIMARY KEY AUTO_INCREMENT, ign varchar(50) NOT NULL, ignby varchar(50) NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'ignored (ign, ignby) VALUES(?, ?);');
			foreach($data as $tmp){
				$stmt->execute($tmp);
			}
			$db->exec('CREATE INDEX ' . PREFIX . 'ign ON ' . PREFIX . 'ignored(ign);');
			$db->exec('CREATE INDEX ' . PREFIX . 'ignby ON ' . PREFIX . 'ignored(ignby);');
			$result=$olddb->query('SELECT postdate, postid, poster, recipient, text FROM ' . PREFIX . 'inbox;');
			$data=$result->fetchAll(PDO::FETCH_NUM);
			$db->exec('DROP TABLE ' . PREFIX . 'inbox;');
			$db->exec('CREATE TABLE ' . PREFIX . "inbox (id integer PRIMARY KEY AUTO_INCREMENT, postdate integer NOT NULL, postid integer NOT NULL UNIQUE, poster varchar(50) NOT NULL, recipient varchar(50) NOT NULL, text text NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'inbox (postdate, postid, poster, recipient, text) VALUES(?, ?, ?, ?, ?);');
			foreach($data as $tmp){
				$stmt->execute($tmp);
			}
			$db->exec('CREATE INDEX ' . PREFIX . 'inbox_poster ON ' . PREFIX . 'inbox(poster);');
			$db->exec('CREATE INDEX ' . PREFIX . 'inbox_recipient ON ' . PREFIX . 'inbox(recipient);');
			$result=$olddb->query('SELECT filtermatch, filterreplace, regex FROM ' . PREFIX . 'linkfilter;');
			$data=$result->fetchAll(PDO::FETCH_NUM);
			$db->exec('DROP TABLE ' . PREFIX . 'linkfilter;');
			$db->exec('CREATE TABLE ' . PREFIX . "linkfilter (id integer PRIMARY KEY AUTO_INCREMENT, filtermatch varchar(255) NOT NULL, filterreplace varchar(255) NOT NULL, regex smallint NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'linkfilter (filtermatch, filterreplace, regex) VALUES(?, ?, ?);');
			foreach($data as $tmp){
				$stmt->execute($tmp);
			}
			$result=$olddb->query('SELECT nickname, passhash, status, refresh, bgcolour, regedby, lastlogin, timestamps, embed, incognito, style, nocache, tz, eninbox, sortupdown, hidechatters FROM ' . PREFIX . 'members;');
			$data=$result->fetchAll(PDO::FETCH_NUM);
			$db->exec('DROP TABLE ' . PREFIX . 'members;');
			$db->exec('CREATE TABLE ' . PREFIX . "members (id integer PRIMARY KEY AUTO_INCREMENT, nickname varchar(50) NOT NULL UNIQUE, passhash char(32) NOT NULL, status smallint NOT NULL, refresh smallint NOT NULL, bgcolour char(6) NOT NULL, regedby varchar(50) DEFAULT '', lastlogin integer DEFAULT 0, timestamps smallint NOT NULL, embed smallint NOT NULL, incognito smallint NOT NULL, style varchar(255) NOT NULL, nocache smallint NOT NULL, tz smallint NOT NULL, eninbox smallint NOT NULL, sortupdown smallint NOT NULL, hidechatters smallint NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'members (nickname, passhash, status, refresh, bgcolour, regedby, lastlogin, timestamps, embed, incognito, style, nocache, tz, eninbox, sortupdown, hidechatters) VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);');
			foreach($data as $tmp){
				$stmt->execute($tmp);
			}
			$result=$olddb->query('SELECT postdate, poststatus, poster, recipient, text, delstatus FROM ' . PREFIX . 'messages;');
			$data=$result->fetchAll(PDO::FETCH_NUM);
			$db->exec('DROP TABLE ' . PREFIX . 'messages;');
			$db->exec('CREATE TABLE ' . PREFIX . "messages (id integer PRIMARY KEY AUTO_INCREMENT, postdate integer NOT NULL, poststatus smallint NOT NULL, poster varchar(50) NOT NULL, recipient varchar(50) NOT NULL, text text NOT NULL, delstatus smallint NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'messages (postdate, poststatus, poster, recipient, text, delstatus) VALUES(?, ?, ?, ?, ?, ?);');
			foreach($data as $tmp){
				$stmt->execute($tmp);
			}
			$db->exec('CREATE INDEX ' . PREFIX . 'poster ON ' . PREFIX . 'messages (poster);');
			$db->exec('CREATE INDEX ' . PREFIX . 'recipient ON ' . PREFIX . 'messages(recipient);');
			$db->exec('CREATE INDEX ' . PREFIX . 'postdate ON ' . PREFIX . 'messages(postdate);');
			$db->exec('CREATE INDEX ' . PREFIX . 'poststatus ON ' . PREFIX . 'messages(poststatus);');
			$result=$olddb->query('SELECT type, lastedited, editedby, text FROM ' . PREFIX . 'notes;');
			$data=$result->fetchAll(PDO::FETCH_NUM);
			$db->exec('DROP TABLE ' . PREFIX . 'notes;');
			$db->exec('CREATE TABLE ' . PREFIX . "notes (id integer PRIMARY KEY AUTO_INCREMENT, type char(5) NOT NULL, lastedited integer NOT NULL, editedby varchar(50) NOT NULL, text text NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'notes (type, lastedited, editedby, text) VALUES(?, ?, ?, ?);');
			foreach($data as $tmp){
				$stmt->execute($tmp);
			}
			$result=$olddb->query('SELECT setting, value FROM ' . PREFIX . 'settings;');
			$data=$result->fetchAll(PDO::FETCH_NUM);
			$db->exec('DROP TABLE ' . PREFIX . 'settings;');
			$db->exec('CREATE TABLE ' . PREFIX . "settings (setting varchar(50) NOT NULL PRIMARY KEY, value text NOT NULL) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;");
			$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'settings (setting, value) VALUES(?, ?);');
			foreach($data as $tmp){
				$stmt->execute($tmp);
			}
		}catch(PDOException $e){
			send_fatal_error(_('No connection to database!'));
		}
	}
	if($dbversion<33){
		$db->exec('CREATE TABLE ' . PREFIX . "files (id $primary, postid integer NOT NULL UNIQUE, filename varchar(255) NOT NULL, hash char(40) NOT NULL, type varchar(255) NOT NULL, data $longtext NOT NULL)$diskengine$charset;");
		$db->exec('CREATE INDEX ' . PREFIX . 'files_hash ON ' . PREFIX . 'files(hash);');
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('enfileupload', '0'), ('msgattache', '%2\$s [%1\$s]'), ('maxuploadsize', '1024');");
	}
	if($dbversion<34){
		$msg.='<br>'._('Note: Default CSS is now hardcoded and can be removed from the CSS setting');
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD COLUMN nocache_old smallint NOT NULL DEFAULT 0;');
	}
	if($dbversion<37){
		$db->exec('ALTER TABLE ' . PREFIX . 'members MODIFY tz varchar(255) NOT NULL;');
		$db->exec('UPDATE ' . PREFIX . "members SET tz='UTC';");
		$db->exec('UPDATE ' . PREFIX . "settings SET value='UTC' WHERE setting='defaulttz';");
	}
	if($dbversion<38){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('nextcron', '0');");
		$db->exec('DELETE FROM ' . PREFIX . 'inbox WHERE recipient NOT IN (SELECT nickname FROM ' . PREFIX . 'members);'); // delete inbox of members who deleted themselves
	}
	if($dbversion<39){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting, value) VALUES ('personalnotes', '1');");
		$result=$db->query('SELECT type, id FROM ' . PREFIX . 'notes;');
		$data = [];
		while($tmp=$result->fetch(PDO::FETCH_NUM)){
			if($tmp[0]==='admin'){
				$tmp[0]=0;
			}else{
				$tmp[0]=1;
			}
			$data[]=$tmp;
		}
		$db->exec('ALTER TABLE ' . PREFIX . 'notes MODIFY type smallint NOT NULL;');
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'notes SET type=? WHERE id=?;');
		foreach($data as $tmp){
			$stmt->execute($tmp);
		}
		$db->exec('CREATE INDEX ' . PREFIX . 'notes_type ON ' . PREFIX . 'notes(type);');
		$db->exec('CREATE INDEX ' . PREFIX . 'notes_editedby ON ' . PREFIX . 'notes(editedby);');
	}
	if($dbversion<41){
		$db->exec('DROP TABLE ' . PREFIX . 'sessions;');
		$db->exec('CREATE TABLE ' . PREFIX . "sessions (id $primary, session char(32) NOT NULL UNIQUE, nickname varchar(50) NOT NULL UNIQUE, status smallint NOT NULL, refresh smallint NOT NULL, style varchar(255) NOT NULL, lastpost integer NOT NULL, passhash varchar(255) NOT NULL, postid char(6) NOT NULL DEFAULT '000000', useragent varchar(255) NOT NULL, kickmessage varchar(255) DEFAULT '', bgcolour char(6) NOT NULL, entry integer NOT NULL, timestamps smallint NOT NULL, embed smallint NOT NULL, incognito smallint NOT NULL, ip varchar(45) NOT NULL, nocache smallint NOT NULL, tz varchar(255) NOT NULL, eninbox smallint NOT NULL, sortupdown smallint NOT NULL, hidechatters smallint NOT NULL, nocache_old smallint NOT NULL)$memengine$charset;");
		$db->exec('CREATE INDEX ' . PREFIX . 'status ON ' . PREFIX . 'sessions(status);');
		$db->exec('CREATE INDEX ' . PREFIX . 'lastpost ON ' . PREFIX . 'sessions(lastpost);');
		$db->exec('CREATE INDEX ' . PREFIX . 'incognito ON ' . PREFIX . 'sessions(incognito);');
		$result=$db->query('SELECT nickname, passhash, status, refresh, bgcolour, regedby, lastlogin, timestamps, embed, incognito, style, nocache, nocache_old, tz, eninbox, sortupdown, hidechatters FROM ' . PREFIX . 'members;');
		$members=$result->fetchAll(PDO::FETCH_NUM);
		$result=$db->query('SELECT postdate, postid, poster, recipient, text FROM ' . PREFIX . 'inbox;');
		$inbox=$result->fetchAll(PDO::FETCH_NUM);
		$db->exec('DROP TABLE ' . PREFIX . 'inbox;');
		$db->exec('DROP TABLE ' . PREFIX . 'members;');
		$db->exec('CREATE TABLE ' . PREFIX . "members (id $primary, nickname varchar(50) NOT NULL UNIQUE, passhash varchar(255) NOT NULL, status smallint NOT NULL, refresh smallint NOT NULL, bgcolour char(6) NOT NULL, regedby varchar(50) DEFAULT '', lastlogin integer DEFAULT 0, timestamps smallint NOT NULL, embed smallint NOT NULL, incognito smallint NOT NULL, style varchar(255) NOT NULL, nocache smallint NOT NULL, nocache_old smallint NOT NULL, tz varchar(255) NOT NULL, eninbox smallint NOT NULL, sortupdown smallint NOT NULL, hidechatters smallint NOT NULL)$diskengine$charset");
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'members (nickname, passhash, status, refresh, bgcolour, regedby, lastlogin, timestamps, embed, incognito, style, nocache, nocache_old, tz, eninbox, sortupdown, hidechatters) VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?);');
		foreach($members as $tmp){
			$stmt->execute($tmp);
		}
		$db->exec('CREATE TABLE ' . PREFIX . "inbox (id $primary, postdate integer NOT NULL, postid integer NOT NULL UNIQUE, poster varchar(50) NOT NULL, recipient varchar(50) NOT NULL, text text NOT NULL)$diskengine$charset;");
		$stmt=$db->prepare('INSERT INTO ' . PREFIX . 'inbox (postdate, postid, poster, recipient, text) VALUES(?, ?, ?, ?, ?);');
		foreach($inbox as $tmp){
			$stmt->execute($tmp);
		}
		$db->exec('CREATE INDEX ' . PREFIX . 'inbox_poster ON ' . PREFIX . 'inbox(poster);');
		$db->exec('CREATE INDEX ' . PREFIX . 'inbox_recipient ON ' . PREFIX . 'inbox(recipient);');
		$db->exec('ALTER TABLE ' . PREFIX . 'inbox ADD FOREIGN KEY (recipient) REFERENCES ' . PREFIX . 'members(nickname) ON DELETE CASCADE ON UPDATE CASCADE;');
	}
	if($dbversion<42){
		$db->exec('INSERT IGNORE INTO ' . PREFIX . "settings (setting, value) VALUES ('filtermodkick', '1');");
	}
	if($dbversion<43){
		$stmt = $db->prepare('INSERT IGNORE INTO ' . PREFIX . "settings (setting, value) VALUES ('metadescription', ?);");
		$stmt->execute([_('A chat community')]);
	}
	if($dbversion<44){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting,value) VALUES ('publicnotes', '0');");
	}
	if($dbversion<45){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting,value) VALUES ('memkickalways', '0'), ('sysmessagetxt', 'ℹ️ &nbsp;'),('namedoers', '1');");
	}
	if($dbversion<46){
		$db->exec('ALTER TABLE ' . PREFIX . 'members ADD COLUMN loginfails integer unsigned NOT NULL DEFAULT 0;');
	}
	if($dbversion<47){
		$db->exec('INSERT INTO ' . PREFIX . "settings (setting,value) VALUES ('hide_reload_post_box', '0'), ('hide_reload_messages', '0'),('hide_profile', '0'),('hide_admin', '0'),('hide_notes', '0'),('hide_clone', '0'),('hide_rearrange', '0'),('hide_help', '0'),('max_refresh_rate', '150'),('min_refresh_rate', '5'),('postbox_delete_globally', '0'),('allow_js', '1');");
	}
	update_setting('dbversion', DBVERSION);
	if($msgencrypted!==MSGENCRYPTED){
		if(!extension_loaded('sodium')){
			send_fatal_error(sprintf(_('The %s extension of PHP is required for the encryption feature. Please install it first or set the encrypted setting back to false.'), 'sodium'));
		}
		$result=$db->query('SELECT id, text FROM ' . PREFIX . 'messages;');
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'messages SET text=? WHERE id=?;');
		while($message=$result->fetch(PDO::FETCH_ASSOC)){
			try {
				if(MSGENCRYPTED){
					$message['text']=base64_encode(sodium_crypto_aead_aes256gcm_encrypt($message['text'], '', AES_IV, ENCRYPTKEY));
				}else{
					$message['text']=sodium_crypto_aead_aes256gcm_decrypt(base64_decode($message['text']), null, AES_IV, ENCRYPTKEY);
				}
			} catch (SodiumException $e){
				send_error($e->getMessage());
			}
			$stmt->execute([$message['text'], $message['id']]);
		}
		$result=$db->query('SELECT id, text FROM ' . PREFIX . 'notes;');
		$stmt=$db->prepare('UPDATE ' . PREFIX . 'notes SET text=? WHERE id=?;');
		while($message=$result->fetch(PDO::FETCH_ASSOC)){
			try {
				if(MSGENCRYPTED){
					$message['text']=base64_encode(sodium_crypto_aead_aes256gcm_encrypt($message['text'], '', AES_IV, ENCRYPTKEY));
				}else{
					$message['text']=sodium_crypto_aead_aes256gcm_decrypt(base64_decode($message['text']), null, AES_IV, ENCRYPTKEY);
				}
			} catch (SodiumException $e){
				send_error($e->getMessage());
			}
			$stmt->execute([$message['text'], $message['id']]);
		}
		update_setting('msgencrypted', (int) MSGENCRYPTED);
	}
	send_update($msg);
}

function get_setting(string $setting) : string {
	global $db, $memcached;
	$value = '';
	if($db instanceof PDO && ( !MEMCACHED || ! ($value = $memcached->get(DBNAME . '-' . PREFIX . "settings-$setting") ) ) ){
		try {
			$stmt = $db->prepare( 'SELECT value FROM ' . PREFIX . 'settings WHERE setting=?;' );
			$stmt->execute( [ $setting ] );
			$stmt->bindColumn( 1, $value );
			$stmt->fetch( PDO::FETCH_BOUND );
			if ( MEMCACHED ) {
				$memcached->set( DBNAME . '-' . PREFIX . "settings-$setting", $value );
			}
		} catch (Exception $e){
			return '';
		}
	}
	return $value;
}

function update_setting(string $setting, $value): void
{
	global $db, $memcached;
	$stmt=$db->prepare('UPDATE ' . PREFIX . 'settings SET value=? WHERE setting=?;');
	$stmt->execute([$value, $setting]);
	if(MEMCACHED){
		$memcached->set(DBNAME . '-' . PREFIX . "settings-$setting", $value);
	}
}

// configuration, defaults and internals

function check_db(): void
{
	global $db, $memcached;
	$options=[PDO::ATTR_ERRMODE=>PDO::ERRMODE_EXCEPTION, PDO::ATTR_PERSISTENT=>PERSISTENT];
	try{
		if(DBDRIVER===0){
			if(!extension_loaded('pdo_mysql')){
				send_fatal_error(sprintf(_('The %s extension of PHP is required for the selected database driver. Please install it first.'), 'pdo_mysql'));
			}
			$db=new PDO('mysql:host=' . DBHOST . ';dbname=' . DBNAME . ';charset=utf8mb4', DBUSER, DBPASS, $options);
		}elseif(DBDRIVER===1){
			if(!extension_loaded('pdo_pgsql')){
				send_fatal_error(sprintf(_('The %s extension of PHP is required for the selected database driver. Please install it first.'), 'pdo_pgsql'));
			}
			$db=new PDO('pgsql:host=' . DBHOST . ';dbname=' . DBNAME, DBUSER, DBPASS, $options);
		}else{
			if(!extension_loaded('pdo_sqlite')){
				send_fatal_error(sprintf(_('The %s extension of PHP is required for the selected database driver. Please install it first.'), 'pdo_sqlite'));
			}
			$db=new PDO('sqlite:' . SQLITEDBFILE, NULL, NULL, $options);
			$db->exec('PRAGMA foreign_keys = ON;');
		}
	}catch(PDOException $e){
		try{
			//Attempt to create database
			if(DBDRIVER===0){
				$db=new PDO('mysql:host=' . DBHOST, DBUSER, DBPASS, $options);
				if(false!==$db->exec('CREATE DATABASE ' . DBNAME)){
					$db=new PDO('mysql:host=' . DBHOST . ';dbname=' . DBNAME . ';charset=utf8mb4', DBUSER, DBPASS, $options);
				}else{
					send_fatal_error(_('No connection to database, please create a database and edit the script to use the correct database with given username and password!'));
				}

			}elseif(DBDRIVER===1){
				$db=new PDO('pgsql:host=' . DBHOST, DBUSER, DBPASS, $options);
				if(false!==$db->exec('CREATE DATABASE ' . DBNAME)){
					$db=new PDO('pgsql:host=' . DBHOST . ';dbname=' . DBNAME, DBUSER, DBPASS, $options);
				}else{
					send_fatal_error(_('No connection to database, please create a database and edit the script to use the correct database with given username and password!'));
				}
			}else{
				if(isset($_REQUEST['action']) && $_REQUEST['action']==='setup'){
					send_fatal_error(_('No connection to database, please create a database and edit the script to use the correct database with given username and password!'));
				}else{
					send_fatal_error(_('No connection to database!'));
				}
			}
		}catch(PDOException $e){
			if(isset($_REQUEST['action']) && $_REQUEST['action']==='setup'){
				send_fatal_error(_('No connection to database, please create a database and edit the script to use the correct database with given username and password!'));
			}else{
				send_fatal_error(_('No connection to database!'));
			}
		}
	}
	if(MEMCACHED){
		if(!extension_loaded('memcached')){
			send_fatal_error(_('The memcached extension of PHP is required for the caching feature. Please install it first or set the memcached setting back to false.'));
		}
		$memcached=new Memcached();
		$memcached->addServer(MEMCACHEDHOST, MEMCACHEDPORT);
	}
	if(!isset($_REQUEST['action']) || $_REQUEST['action']==='setup'){
		if(!check_init()){
			send_init();
		}
		update_db();
	}elseif($_REQUEST['action']==='init'){
		init_chat();
	}
}

function load_fonts() : array {
	return [
		'Arial'			=>"font-family:Arial,Helvetica,sans-serif;",
		'Book Antiqua'		=>"font-family:'Book Antiqua','MS Gothic',serif;",
		'Comic'			=>"font-family:'Comic Sans MS',Papyrus,sans-serif;",
		'Courier'		=>"font-family:'Courier New',Courier,monospace;",
		'Cursive'		=>"font-family:Cursive,Papyrus,sans-serif;",
		'Fantasy'		=>"font-family:Fantasy,Futura,Papyrus,sans;",
		'Garamond'		=>"font-family:Garamond,Palatino,serif;",
		'Georgia'		=>"font-family:Georgia,'Times New Roman',Times,serif;",
		'Serif'			=>"font-family:'MS Serif','New York',serif;",
		'System'		=>"font-family:System,Chicago,sans-serif;",
		'Times New Roman'	=>"font-family:'Times New Roman',Times,serif;",
		'Verdana'		=>"font-family:Verdana,Geneva,Arial,Helvetica,sans-serif;",
	];
}

function load_lang(): void
{
	global $language, $locale, $dir;
	if(isset($_REQUEST['lang']) && isset(LANGUAGES[$_REQUEST['lang']])){
		$locale = LANGUAGES[$_REQUEST['lang']]['locale'];
		$language = $_REQUEST['lang'];
		$dir = LANGUAGES[$_REQUEST['lang']]['dir'];
		set_secure_cookie('language', $language);
	}elseif(isset($_COOKIE['language']) && isset(LANGUAGES[$_COOKIE['language']])){
		$locale = LANGUAGES[$_COOKIE['language']]['locale'];
		$language = $_COOKIE['language'];
		$dir = LANGUAGES[$_COOKIE['language']]['dir'];
	}elseif(!empty($_SERVER['HTTP_ACCEPT_LANGUAGE'])){
		$prefLocales = array_reduce(
			explode(',', $_SERVER['HTTP_ACCEPT_LANGUAGE']),
			function (array $res, string $el) {
				list($l, $q) = array_merge(explode(';q=', $el), [1]);
				$res[$l] = (float) $q;
				return $res;
			}, []);
		arsort($prefLocales);
		foreach($prefLocales as $l => $q){
			$lang = locale_lookup(array_keys(LANGUAGES), $l);
			if(!empty($lang)){
				$locale = LANGUAGES[$lang]['locale'];
				$language = $lang;
				$dir = LANGUAGES[$lang]['dir'];
				set_secure_cookie('language', $language);
				break;
			}
		}
	}
}

function load_config(): void
{
	mb_internal_encoding('UTF-8');
	define('VERSION', '1.24.1'); // Script version
	define('DBVERSION', 47); // Database layout version
	define('MSGENCRYPTED', false); // Store messages encrypted in the database to prevent other database users from reading them - true/false - visit the setup page after editing!
	define('ENCRYPTKEY_PASS', 'MY_SECRET_KEY'); // Recommended length: 32. Encryption key for messages
	define('AES_IV_PASS', '012345678912'); // Recommended length: 12. AES Encryption IV
	define('DBHOST', 'localhost'); // Database host
	define('DBUSER', 'www-data'); // Database user
	define('DBPASS', 'YOUR_DB_PASS'); // Database password
	define('DBNAME', 'public_chat'); // Database
	define('PERSISTENT', true); // Use persistent database conection true/false
	define('PREFIX', ''); // Prefix - Set this to a unique value for every chat, if you have more than 1 chats on the same database or domain - use only alpha-numeric values (A-Z, a-z, 0-9, or _) other symbols might break the queries
	define('MEMCACHED', false); // Enable/disable memcached caching true/false - needs memcached extension and a memcached server.
	if(MEMCACHED){
		define('MEMCACHEDHOST', 'localhost'); // Memcached host
		define('MEMCACHEDPORT', '11211'); // Memcached port
	}
	define('DBDRIVER', 0); // Selects the database driver to use - 0=MySQL, 1=PostgreSQL, 2=sqlite
	if(DBDRIVER===2){
		define('SQLITEDBFILE', 'public_chat.sqlite'); // Filepath of the sqlite database, if sqlite is used - make sure it is writable for the webserver user
	}
	define('COOKIENAME', PREFIX . 'chat_session'); // Cookie name storing the session information
	define('LANG', 'en'); // Default language
	if (MSGENCRYPTED){
		if (version_compare(PHP_VERSION, '7.2.0') < 0) {
			die("You need at least PHP >= 7.2.x");
		}
		//Do not touch: Compute real keys needed by encryption functions
		if (strlen(ENCRYPTKEY_PASS) !== SODIUM_CRYPTO_AEAD_AES256GCM_KEYBYTES){
			define('ENCRYPTKEY', substr(hash("sha512/256",ENCRYPTKEY_PASS),0, SODIUM_CRYPTO_AEAD_AES256GCM_KEYBYTES));
		}else{
			define('ENCRYPTKEY', ENCRYPTKEY_PASS);
		}
		if (strlen(AES_IV_PASS) !== SODIUM_CRYPTO_AEAD_AES256GCM_NPUBBYTES){
			define('AES_IV', substr(hash("sha512/256",AES_IV_PASS), 0, SODIUM_CRYPTO_AEAD_AES256GCM_NPUBBYTES));
		}else{
			define('AES_IV', AES_IV_PASS);
		}
	}
	//define('RESET_SUPERADMIN_PASSWORD', 'changeme'); //Use this to reset your superadmin password in case you forgot it
}