import express from 'express';
import { enqueueCmd } from '../services/natQueue.js';
import { runRouterCmds } from '../services/sshExec.js';
import { error, info } from '../util/Console.js';

const router = express.Router();

const SAFE_CMD_REGX = /^\s*(show|ping|traceroute|terminal length|show ip|show interfaces|show version|show running-config|show ip nat)\b/i;

function checkAdminToken(req) {
    const token = req.headers['x-admin-token'] || req.body.token || req.query.token;
    const saved = req.app.get('adminToken');
    const expiry = req.app.get('adminTokenExpory') || 0;
    if (!token || !saved) return false;
    if (Date.now() > expiry) return false;
    return token === saved;
}

router.post('/', async (req, res) => {
    const cmd = (req.body && req.body.cmd) || '';
    if (!cmd) return res.status(400).json({ error: 'no command' });
    const isAdmin = checkAdminToken(req);
    if (!isAdmin && !SAFE_CMD_REGX.test(cmd)) return res.status(403).json({ error: 'not allowed' });

    info(`Exec requested${isAdmin ? ' [admin]' : ''}: ${cmd}`);

    try {
        enqueueCmd(() => runRouterCmds([cmd]));
        res.json({ success: true });
    } catch (err) {
        error(err);
        res.status(500).json({ error: 'exec failed' });
    }
});

router.get('/stream', (req, res) => {
    const cmd = req.query.cmd || '';
    if (!cmd) return res.status(400).send('no command');
    const isAdmin = checkAdminToken(req);
    if (!isAdmin && !SAFE_CMD_REGX.test(cmd)) return res.status(400).send('not allowed');

    res.setHeader('Content-Type', 'text/event-stream');
    res.setHeader('Cache-Control', 'no-cache');
    res.setHeader('Connection', 'keep-alive');
    res.flushHeaders && res.flushHeaders();

    enqueueCmd(() => new Promise(async (resolve) => {
        try {
            await runRouterCmds([cmd], chunk => {
                res.write(`data: ${chunk.replace(/\n/g, '\\n')}\n\n`);
            });
            res.write('data: [[EOF]]\n\n');
            res.end();
            resolve()
        } catch (err) {
            res.write(`data: [ERROR] ${String(err)}\n\n`);
            res.end();
            resolve();
        }
    }));
});

export default router;