<?php

require_once('inc/session.inc.php');

class User
{

	private static $user = false;

	public static function isLoggedIn(): bool
	{
		return self::$user !== false;
	}

	public static function getId()
	{
		if (!self::isLoggedIn())
			return false;
		return self::$user['userid'];
	}

	public static function getName()
	{
		if (!self::isLoggedIn())
			return false;
		return self::$user['fullname'];
	}

	public static function hasPermission($permission, $locationid = NULL)
	{
		if (!self::isLoggedIn())
			return false;
		if (Module::isAvailable("permissionmanager")) {
			if ($permission[0] === '.') {
				$permission = substr($permission, 1);
			} else {
				if (class_exists('Page')) {
					$module = Page::getModule();
					if ($module !== false) {
						$module = $module->getIdentifier();
					}
				} else {
					$module = strtolower(Request::any('do'));
				}
				$permission = $module ? $module . "." . $permission : $permission;
			}
			return PermissionUtil::userHasPermission(self::$user['userid'], $permission, $locationid);
		}
		if (self::$user['permissions'] & Permission::get('superadmin'))
			return true;
		return (self::$user['permissions'] & Permission::get($permission)) != 0;
	}

	/**
	 * Confirm current user has the given permission, stop execution and show error message
	 * otherwise.
	 * @param string $permission Permission to check for
	 * @param null|int $locationid location this permission has to apply to, NULL if any location is sufficient
	 * @param null|string $redirect page to redirect to if permission is not given, NULL defaults to main page
	 */
	public static function assertPermission($permission, $locationid = NULL, $redirect = NULL)
	{
		if (User::hasPermission($permission, $locationid))
			return;
		if (AJAX) {
			Message::renderList();
			exit;
		}
		if (!is_null($redirect)) {
			Message::addError('main.no-permission');
			Util::redirect($redirect);
		} elseif (Module::isAvailable('permissionmanager')) {
			if ($permission[0] !== '.') {
				$module = Page::getModule();
				if ($module !== false) {
					$permission = '.' . $module->getIdentifier() . '.' . $permission;
				}
			}
			Util::redirect('?do=permissionmanager&show=denied&permission=' . urlencode($permission));
		} else {
			Message::addError('main.no-permission');
			Util::redirect('?do=main');
		}
	}

	public static function getAllowedLocations(string $permission): array
	{
		if (!self::isLoggedIn())
			return [];
		if (Module::isAvailable("permissionmanager")) {
			if ($permission[0] === '.') {
				$permission = substr($permission, 1);
			} else {
				$module = Page::getModule();
				$permission = $module ? $module->getIdentifier() . "." . $permission : $permission;
			}
			return PermissionUtil::getAllowedLocations(self::$user['userid'], $permission);
		}
		if (self::$user['permissions'] & Permission::get('superadmin')) {
			if (Module::isAvailable('locations')) {
				$a = array_keys(Location::getLocationsAssoc());
				$a[] = 0;
			} else {
				$a = [0];
			}
			return $a;
		}
		return [];
	}

	public static function load()
	{
		if (self::isLoggedIn())
			return true;
		if (Session::load()) {
			if (empty(Session::get('token'))) {
				self::generateToken();
			}
			$uid = Session::getUserId();
			if ($uid < 1)
				self::logout();
			self::$user = Database::queryFirst('SELECT * FROM user WHERE userid = :uid LIMIT 1', array(':uid' => $uid));
			if (self::$user === false)
				self::logout();
			settype(self::$user['userid'], 'int');
			return true;
		}
		return false;
	}

	public static function testPassword($userid, $password)
	{
		$ret = Database::queryFirst('SELECT passwd FROM user WHERE userid = :userid LIMIT 1', compact('userid'));
		if ($ret === false)
			return false;
		return Crypto::verify($password, $ret['passwd']);
	}

	public static function updatePassword($password)
	{
		if (!self::isLoggedIn())
			return false;
		$passwd = Crypto::hash6($password);
		$userid = self::getId();
		return Database::exec('UPDATE user SET passwd = :passwd WHERE userid = :userid LIMIT 1', compact('userid', 'passwd')) > 0;
	}

	public static function login(string $user, string $pass, bool $fixedIp)
	{
		$ret = Database::queryFirst('SELECT userid, passwd FROM user WHERE login = :user LIMIT 1', array(':user' => $user));
		if ($ret === false)
			return false;
		if (!Crypto::verify($pass, $ret['passwd']))
			return false;
		Session::create($ret['passwd'], $ret['userid'], $fixedIp);
		self::generateToken($ret['passwd']);
		return true;
	}

	public static function logout()
	{
		Session::delete();
		Header('Location: ?do=Main&fromlogout');
		exit(0);
	}

	public static function setLastSeenEvent($eventid)
	{
		if (!self::isLoggedIn())
			return;
		Database::exec("UPDATE user SET lasteventid = :eventid WHERE userid = :userid LIMIT 1", array(
			'eventid' => $eventid,
			'userid' => self::$user['userid']
		));
		self::$user['lasteventid'] = $eventid;
	}

	public static function getLastSeenEvent()
	{
		if (!self::isLoggedIn())
			return false;
		return self::$user['lasteventid'];
	}

	private static function generateToken($salt = '')
	{
		Session::set('token', md5($salt . ','
			. rand() . ','
			. time() . ','
			. rand() . ','
			. $_SERVER['REMOTE_ADDR'] . ','
			. rand() . ','
			. $_SERVER['REMOTE_PORT'] . ','
			. rand() . ','
			. $_SERVER['HTTP_USER_AGENT']), false);
	}

}