BanModel::applyBan PHP Method

    public function applyBan($NewBan = null, $OldBan = null)
    {
        if (!$NewBan && !$OldBan) {
            return;
        }
        $OldUsers = array();
        $NewUsers = array();
        $NewUserIDs = array();
        $AllBans = $this->allBans();
        if ($NewBan) {
            // Get a list of users affected by the new ban.
            if (isset($NewBan['BanID'])) {
                $AllBans[$NewBan['BanID']] = $NewBan;
            }
            // Protect against a lack of inet6_ntoa, which wasn't introduced until MySQL 5.6.3.
            try {
                $NewUsers = $this->SQL->select('u.UserID, u.Banned')->from('User u')->where($this->banWhere($NewBan))->where('Admin', 0)->get()->resultArray();
            } catch (Exception $e) {
                Logger::log(Logger::ERROR, $e->getMessage());
                $NewUsers = [];
            }
            $NewUserIDs = array_column($NewUsers, 'UserID');
        } elseif (isset($OldBan['BanID'])) {
            unset($AllBans[$OldBan['BanID']]);
        }
        if ($OldBan) {
            // Get a list of users affected by the old ban.
            // Protect against a lack of inet6_ntoa, which wasn't introduced until MySQL 5.6.3.
            try {
                $OldUsers = $this->SQL->select('u.UserID, u.LastIPAddress, u.Name, u.Email, u.Banned')->from('User u')->where($this->banWhere($OldBan))->get()->resultArray();
            } catch (Exception $e) {
                Logger::log(Logger::ERROR, $e->getMessage());
                $OldUsers = [];
            }
        }
        // Check users that need to be unbanned.
        foreach ($OldUsers as $User) {
            if (in_array($User['UserID'], $NewUserIDs)) {
                continue;
            }
            // TODO check the user against the other bans.
            $this->saveUser($User, false);
        }
        // Check users that need to be banned.
        foreach ($NewUsers as $User) {
            if (self::isBanned($User['Banned'], BanModel::BAN_AUTOMATIC)) {
                continue;
            }
            $this->saveUser($User, true, $NewBan);
        }
    }