<?php

/**
 * [Discuz!] (C)2001-2099 Discuz! Team
 * This is NOT a freeware, use is subject to license terms
 * https://license.discuz.vip
 */

if (!defined('IN_DISCUZ')) {
	exit('Access Denied');
}

class discuz_application extends discuz_base {


	var $mem = null;

	var $session = null;

	var $config = [];

	var $var = [];

	var $cachelist = [];

	var $init_db = true;
	var $init_setting = true;
	var $init_user = true;
	var $init_session = true;
	var $init_cron = true;
	var $init_misc = true;
	var $init_mobile = true;

	var $initated = false;

	var $superglobal = [
		'GLOBALS' => 1,
		'_GET' => 1,
		'_POST' => 1,
		'_REQUEST' => 1,
		'_COOKIE' => 1,
		'_SERVER' => 1,
		'_ENV' => 1,
		'_FILES' => 1,
	];

	static function &instance() {
		static $object;
		if (empty($object)) {
			$object = new self();
		}
		return $object;
	}

	public function __construct() {
		$this->_init_env();
		$this->_init_input();
		$this->_init_output();
	}

	public function init() {
		if (!$this->initated) {
			$this->_init_db();
		}
		$this->initated = true;
	}

	private function _init_env() {
		error_reporting(E_ERROR);

		define('ICONV_ENABLE', function_exists('iconv'));
		define('MB_ENABLE', function_exists('mb_convert_encoding'));
		define('EXT_OBGZIP', function_exists('ob_gzhandler'));

		define('TIMESTAMP', time());

		if (!defined('DISCUZ_CORE_FUNCTION') && !@include(DISCUZ_ROOT . './source/function/function_core.php')) {
			exit('function_core.php is missing');
		}

		if (function_exists('ini_get')) {
			$memorylimit = @ini_get('memory_limit');
			if ($memorylimit && return_bytes($memorylimit) < 33554432 && function_exists('ini_set')) {
				ini_set('memory_limit', '128m');
			}
		}

		define('IS_ROBOT', checkrobot());

		foreach ($GLOBALS as $key => $value) {
			if (!isset($this->superglobal[$key])) {
				$GLOBALS[$key] = null;
				unset($GLOBALS[$key]);
			}
		}

		global $_G;
		$_G = [
			'uid' => 0,
			'username' => '',
			'adminid' => 0,
			'groupid' => 1,
			'sid' => '',
			'formhash' => '',
			'connectguest' => 0,
			'timestamp' => TIMESTAMP,
			'starttime' => microtime(true),
			'clientip' => $this->_get_client_ip(),
			'remoteport' => $_SERVER['REMOTE_PORT'],
			'referer' => '',
			'charset' => '',
			'gzipcompress' => '',
		];
		$_G['PHP_SELF'] = dhtmlspecialchars($this->_get_script_url());
		$_G['basefilename'] = basename($_G['PHP_SELF']);
		$_G['isHTTPS'] = !empty($_G['config']['output']['forcehttps']) || $this->_is_https();
		$_G['scheme'] = 'http' . ($_G['isHTTPS'] ? 's' : '');
		$_G['siteurl'] = dhtmlspecialchars($_G['scheme'] . '://' . $_SERVER['HTTP_HOST'] . $sitepath . '/');

		$url = parse_url($_G['siteurl']);
		$_G['siteroot'] = $url['path'] ?? '';
		$_G['siteport'] = empty($_SERVER['SERVER_PORT']) || $_SERVER['SERVER_PORT'] == '80' || $_SERVER['SERVER_PORT'] == '443' ? '' : ':' . $_SERVER['SERVER_PORT'];

		$this->var = &$_G;
	}

	private function _get_script_url() {
		if (!isset($this->var['PHP_SELF'])) {
			$scriptName = basename($_SERVER['SCRIPT_FILENAME']);
			if (basename($_SERVER['SCRIPT_NAME']) === $scriptName) {
				$this->var['PHP_SELF'] = $_SERVER['SCRIPT_NAME'];
			} else if (basename($_SERVER['PHP_SELF']) === $scriptName) {
				$this->var['PHP_SELF'] = $_SERVER['PHP_SELF'];
			} else if (isset($_SERVER['ORIG_SCRIPT_NAME']) && basename($_SERVER['ORIG_SCRIPT_NAME']) === $scriptName) {
				$this->var['PHP_SELF'] = $_SERVER['ORIG_SCRIPT_NAME'];
			} else if (($pos = strpos($_SERVER['PHP_SELF'], '/' . $scriptName)) !== false) {
				$this->var['PHP_SELF'] = substr($_SERVER['SCRIPT_NAME'], 0, $pos) . '/' . $scriptName;
			} else if (isset($_SERVER['DOCUMENT_ROOT']) && str_starts_with($_SERVER['SCRIPT_FILENAME'], $_SERVER['DOCUMENT_ROOT'])) {
				$this->var['PHP_SELF'] = str_replace('\\', '/', str_replace($_SERVER['DOCUMENT_ROOT'], '', $_SERVER['SCRIPT_FILENAME']));
				$this->var['PHP_SELF'][0] != '/' && $this->var['PHP_SELF'] = '/' . $this->var['PHP_SELF'];
			} else {
				system_error('request_tainting');
			}
		}
		return $this->var['PHP_SELF'];
	}

	private function _init_input() {
		if (isset($_GET['GLOBALS']) || isset($_POST['GLOBALS']) || isset($_COOKIE['GLOBALS']) || isset($_FILES['GLOBALS'])) {
			exit('request tainting');
		}

		$prelength = strlen($this->config['cookie']['cookiepre']);
		foreach ($_COOKIE as $key => $val) {
			if (substr($key, 0, $prelength) == $this->config['cookie']['cookiepre']) {
				$this->var['cookie'][substr($key, $prelength)] = $val;
			}
		}

		if ($_SERVER['REQUEST_METHOD'] == 'POST' && !empty($_POST)) {
			foreach ($_POST as $k => $v) {
				$_GET[$k] = $v;
			}
		}
	}

	private function _init_output() {

		if (!empty($_SERVER['HTTP_ACCEPT_ENCODING']) && !str_contains($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip')) {
			$this->config['output']['gzip'] = false;
		}

		$allowgzip = $this->config['output']['gzip'] && empty($this->var['inajax']) && $this->var['mod'] != 'attachment' && EXT_OBGZIP;
		setglobal('gzipcompress', $allowgzip);

		if (!ob_start($allowgzip ? 'ob_gzhandler' : null)) {
			ob_start();
		}

		setglobal('charset', $this->config['output']['charset']);
		define('CHARSET', $this->config['output']['charset']);
		if ($this->config['output']['forceheader']) {
			@header('Content-Type: text/html; charset=' . CHARSET);
		}

		if ($this->var['isHTTPS'] && isset($this->config['output']['upgradeinsecure']) && $this->config['output']['upgradeinsecure']) {
			@header('Content-Security-Policy: upgrade-insecure-requests');
		}

	}

	public function reject_robot() {
		if (IS_ROBOT) {
			exit(header('HTTP/1.1 403 Forbidden'));
		}
	}

	private function _is_https() {
		// PHP 标准服务器变量
		if (isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) != 'off') {
			return true;
		}
		// X-Forwarded-Proto 事实标准头部, 用于反代透传 HTTPS 状态
		if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) && strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']) == 'https') {
			return true;
		}
		// 阿里云全站加速私有 HTTPS 状态头部
		// Git 意见反馈 https://gitee.com/Discuz/DiscuzX/issues/I3W5GP
		if (isset($_SERVER['HTTP_X_CLIENT_SCHEME']) && strtolower($_SERVER['HTTP_X_CLIENT_SCHEME']) == 'https') {
			return true;
		}
		// 西部数码建站助手私有 HTTPS 状态头部
		// 官网意见反馈 https://discuz.dismall.com/thread-3849819-1-1.html
		if (isset($_SERVER['HTTP_FROM_HTTPS']) && strtolower($_SERVER['HTTP_FROM_HTTPS']) != 'off') {
			return true;
		}
		// 服务器端口号兜底判断
		if (isset($_SERVER['SERVER_PORT']) && $_SERVER['SERVER_PORT'] == 443) {
			return true;
		}
		return false;
	}

	private function _get_client_ip() {
		$ip = $_SERVER['REMOTE_ADDR'];
		if (!array_key_exists('security', $this->config) || !$this->config['security']['onlyremoteaddr']) {
			if (array_key_exists('ipgetter', $this->config) && !empty($this->config['ipgetter']['setting'])) {
				$s = empty($this->config['ipgetter'][$this->config['ipgetter']['setting']]) ? [] : $this->config['ipgetter'][$this->config['ipgetter']['setting']];
				$c = 'ip_getter_' . $this->config['ipgetter']['setting'];
				$r = $c::get($s);
				$ip = ip::validate_ip($r) ? $r : $ip;
			} elseif (isset($_SERVER['HTTP_CLIENT_IP']) && ip::validate_ip($_SERVER['HTTP_CLIENT_IP'])) {
				$ip = $_SERVER['HTTP_CLIENT_IP'];
			} elseif (isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
				if (strpos($_SERVER['HTTP_X_FORWARDED_FOR'], ',') > 0) {
					$exp = explode(',', $_SERVER['HTTP_X_FORWARDED_FOR']);
					$ip = ip::validate_ip(trim($exp[0])) ? $exp[0] : $ip;
				} else {
					$ip = ip::validate_ip($_SERVER['HTTP_X_FORWARDED_FOR']) ? $_SERVER['HTTP_X_FORWARDED_FOR'] : $ip;
				}
			}
		}
		return $ip;
	}

	private function _init_db() {
		if ($this->init_db && $this->config) {
			if ($this->config['db']['driver'] == 'pdo' && class_exists('PDO')) {
				$driver = 'db_driver_pdo';
				if (getglobal('config/db/slave')) {
					$driver = 'db_driver_pdo_slave';
				}
				$this->var['db_driver'] = 'pdo';
			} else {
				$driver = 'db_driver_mysqli';
				if (getglobal('config/db/slave')) {
					$driver = 'db_driver_mysqli_slave';
				}
				$this->var['db_driver'] = 'mysqli';
			}

			$this->var['mysql_driver'] = $driver;
			DB::init($driver, $this->config['db']);
		}
	}

}