vlan backned

this.app.post('/api/set_vlan_port', (req, res) => {
            const { port, vlan: vlanStr, mode, action } = req.body;
            const vlan = parseInt(vlanStr, 10);

            if (!vports.includes(port)) {
                return res.status(400).json({ error: 'Invalid port' });
            }

            if (!vlans.hasOwnProperty(vlan)) {
                return res.status(400).json({ error: 'Invalid VLAN' });
            }

            if (mode === 'access' && action !== 'default') {
                return res.status(403).json({ error: 'Access mode does not allow modifying VLAN memberships.' });
            }

            if (!portMemberships[port]) portMemberships[port] = {};

            switch (action) {
                case 'default':
                    portMemberships[port] = {};
                    portMemberships[port][vlan] = ['p', 'u'];
                    break;

                case 'tag':
                    portMemberships[port][vlan] = ['t'];
                    break;

                case 'untag':
                    portMemberships[port][vlan] = ['u'];
                    break;

                case 'unmember':
                    delete portMemberships[port][vlan];
                    break;

                default:
                    return res.status(400).json({ error: 'Invalid action' });
            }

            res.json({ message: 'Updated', members: portMemberships[port] });
        });