import express from 'express';
import morgan from 'morgan';
import path from 'path';
import { fileURLToPath } from 'url';
import dgram from 'dgram';
import radius from 'radius';

const app = express();
app.use(express.json());
app.use(morgan('dev'));

// Static files for dashboard
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
app.use(express.static(path.join(__dirname, 'public')));

const VLAN_ID = process.env.VLAN_ID || '2';
const MAX_UP = process.env.MAX_UP || '10000000'; // bits per second
const MAX_DOWN = process.env.MAX_DOWN || '10000000'; // bits per second
const MAX_REQUESTS = parseInt(process.env.MAX_REQUESTS || '200', 10);
const RADIUS_HOST = process.env.RADIUS_HOST || 'freeradius';
const RADIUS_AUTH_PORT = parseInt(process.env.RADIUS_AUTH_PORT || '1812', 10);
const RADIUS_SECRET = process.env.RADIUS_SECRET || process.env.RADIUS_SHARED_SECRET || 'tamosbien';

// In-memory request store + SSE clients
const requests = [];
const sseClients = new Set();

function pushRequest(rec) {
  requests.push(rec);
  while (requests.length > MAX_REQUESTS) requests.shift();
  // Broadcast via SSE
  const payload = `data: ${JSON.stringify(rec)}\n\n`;
  for (const res of sseClients) {
    try { res.write(payload); } catch { /* ignore */ }
  }
}

// Helper: standard Accept with VLAN + bandwidth
function buildAcceptPayload(extra = {}) {
  return {
    control: {
      'Auth-Type': 'Accept',
      ...extra.control,
    },
    reply: {
      'Tunnel-Type': 'VLAN',
      'Tunnel-Medium-Type': 'IEEE-802',
      'Tunnel-Private-Group-Id': String(VLAN_ID),
      'WISPr-Bandwidth-Max-Down': String(MAX_DOWN),
      'WISPr-Bandwidth-Max-Up': String(MAX_UP),
      ...extra.reply,
    },
  };
}

// Normalize attributes from FreeRADIUS rlm_rest JSON
function normalizeAttributes(body = {}) {
  // Newer rlm_rest may send attributes at top-level as { Attr: { type, value: [..] } }
  // or under body.attributes / body.request as plain map.
  const src = body.attributes || body.request || body;
  const out = {};
  for (const [k, v] of Object.entries(src || {})) {
    if (v && typeof v === 'object' && Array.isArray(v.value)) out[k] = v.value[0];
    else out[k] = v;
  }
  return out;
}

// Authorize endpoint: FreeRADIUS rlm_rest calls this in authorize {}
app.post('/authorize', (req, res) => {
  console.log('--- RADIUS Authorize Request ---');
  console.log(JSON.stringify(req.body, null, 2));

  const attrs = normalizeAttributes(req.body);
  const reply = buildAcceptPayload();
  pushRequest({
    id: Date.now() + ':' + Math.random().toString(16).slice(2),
    ts: new Date().toISOString(),
    type: 'authorize',
    attrs,
    decision: 'accept',
    vlan: VLAN_ID,
    bandwidth: { up: MAX_UP, down: MAX_DOWN },
  });
  return res.status(200).json(reply);
});

// Accounting endpoint (opcional)
app.post('/accounting', (req, res) => {
  console.log('--- RADIUS Accounting ---');
  console.log(JSON.stringify(req.body, null, 2));
  pushRequest({
    id: Date.now() + ':' + Math.random().toString(16).slice(2),
    ts: new Date().toISOString(),
    type: 'accounting',
    attrs: normalizeAttributes(req.body),
  });
  return res.status(200).json({});
});

// API: recent requests
app.get('/api/requests', (req, res) => {
  res.json({ items: requests.slice(-MAX_REQUESTS) });
});

// Clear recent requests
app.delete('/api/requests', (req, res) => {
  requests.length = 0;
  // Notify live clients to refresh if they want
  const payload = `event: clear\n` + `data: {"ok":true}\n\n`;
  for (const resSse of sseClients) {
    try { resSse.write(payload); } catch {}
  }
  res.json({ ok: true });
});

// Export CSV of recent requests
app.get('/api/requests.csv', (req, res) => {
  const cols = [
    'ts','type','user','nas','calling','called','decision','vlan','bw_down','bw_up'
  ];
  const lines = [cols.join(',')];
  for (const ev of requests) {
    const attrs = ev.attrs || {};
    const row = [
      ev.ts || '',
      ev.type || '',
      attrs['User-Name'] || attrs['User-Name*0'] || '',
      attrs['NAS-IP-Address'] || attrs['NAS-Identifier'] || '',
      attrs['Calling-Station-Id'] || '',
      attrs['Called-Station-Id'] || '',
      ev.decision || '',
      ev.vlan || '',
      (ev.bandwidth && ev.bandwidth.down) || '',
      (ev.bandwidth && ev.bandwidth.up) || ''
    ];
    const esc = (v) => String(v).includes(',') || String(v).includes('"') || String(v).includes('\n')
      ? '"' + String(v).replace(/"/g, '""') + '"'
      : String(v);
    lines.push(row.map(esc).join(','));
  }
  const csv = lines.join('\n');
  const ts = new Date().toISOString().replace(/[:T]/g, '-').split('.')[0];
  res.setHeader('Content-Type', 'text/csv; charset=utf-8');
  res.setHeader('Content-Disposition', `attachment; filename="radius-events-${ts}.csv"`);
  res.send(csv);
});

// SSE stream for live updates
app.get('/events', (req, res) => {
  res.setHeader('Content-Type', 'text/event-stream');
  res.setHeader('Cache-Control', 'no-cache');
  res.setHeader('Connection', 'keep-alive');
  res.flushHeaders?.();
  // send a hello event
  res.write(`event: hello\n`);
  res.write(`data: {"ok":true}\n\n`);
  sseClients.add(res);
  req.on('close', () => sseClients.delete(res));
});

// Root: serve dashboard
app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// Self-test: send a RADIUS Access-Request to FreeRADIUS
async function sendRadiusSelfTest() {
  return new Promise((resolve, reject) => {
    try {
      const packet = radius.encode({
        code: 'Access-Request',
        secret: RADIUS_SECRET,
        attributes: {
          'User-Name': 'selftest-node',
          'NAS-Identifier': 'node-dashboard',
          'Calling-Station-Id': '001122334455',
        },
      });
      const client = dgram.createSocket('udp4');
      const started = Date.now();
      const timeout = setTimeout(() => {
        client.close();
        reject(new Error('timeout'));
      }, 4000);
      client.on('message', (msg) => {
        clearTimeout(timeout);
        client.close();
        const res = radius.decode({ packet: msg, secret: RADIUS_SECRET });
        resolve({
          code: res.code,
          rtt_ms: Date.now() - started,
        });
      });
      client.send(packet, 0, packet.length, RADIUS_AUTH_PORT, RADIUS_HOST, (err) => {
        if (err) {
          clearTimeout(timeout);
          client.close();
          reject(err);
        }
      });
    } catch (e) {
      reject(e);
    }
  });
}

app.post('/test/radius', async (req, res) => {
  try {
    const result = await sendRadiusSelfTest();
    pushRequest({
      id: Date.now() + ':' + Math.random().toString(16).slice(2),
      ts: new Date().toISOString(),
      type: 'selftest',
      attrs: { 'User-Name': 'selftest-node' },
      decision: result.code,
    });
    res.json({ ok: true, result });
  } catch (err) {
    pushRequest({
      id: Date.now() + ':' + Math.random().toString(16).slice(2),
      ts: new Date().toISOString(),
      type: 'selftest',
      attrs: { 'User-Name': 'selftest-node' },
      decision: 'error',
      error: String(err && err.message || err),
    });
    res.status(500).json({ ok: false, error: String(err && err.message || err) });
  }
});

const port = process.env.PORT || 3000;
app.listen(port, () => {
  console.log(`Node RADIUS REST API listening on :${port}`);
});