import { Router } from 'express'
import axios from 'axios'

const router = Router()

const HISTORY_SIZE = 20
const history: { ts: number; rx: number; tx: number }[] = []

function soap(action: string, service: string, body = ''): string {
  return `<?xml version="1.0" encoding="utf-8"?><s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"><s:Body><u:${action} xmlns:u="${service}">${body}</u:${action}></s:Body></s:Envelope>`
}

function tag(xml: string, name: string): string {
  const m = xml.match(new RegExp(`<(?:[^:>]*:)?${name}>([^<]*)<`))
  return m?.[1]?.trim() ?? ''
}

async function soapReq(host: string, path: string, service: string, action: string): Promise<string> {
  const res = await axios.post(`${host}:49000${path}`, soap(action, service), {
    headers: {
      'Content-Type': 'text/xml; charset="utf-8"',
      SOAPAction: `"${service}#${action}"`,
    },
    timeout: 5000,
  })
  return res.data as string
}

router.get('/status', async (_req, res) => {
  try {
    const host = process.env.FRITZBOX_HOST
    if (!host) {
      res.status(503).json({ error: 'FRITZBOX_HOST not configured' })
      return
    }

    const [addonXml, ipXml, statusXml] = await Promise.all([
      soapReq(host, '/igdupnp/control/WANCommonIFC1',
        'urn:schemas-upnp-org:service:WANCommonInterfaceConfig:1', 'GetAddonInfos'),
      soapReq(host, '/igdupnp/control/WANIPConn1',
        'urn:schemas-upnp-org:service:WANIPConnection:1', 'GetExternalIPAddress'),
      soapReq(host, '/igdupnp/control/WANIPConn1',
        'urn:schemas-upnp-org:service:WANIPConnection:1', 'GetStatusInfo'),
    ])

    // Bytes/sec — FritzBox provides instantaneous rates
    const rxRate = Number(tag(addonXml, 'NewByteReceiveRate') || tag(addonXml, 'NewBytesReceiveRate') || '0')
    const txRate = Number(tag(addonXml, 'NewByteSendRate')    || tag(addonXml, 'NewBytesSendRate')    || '0')

    history.push({ ts: Date.now(), rx: rxRate, tx: txRate })
    if (history.length > HISTORY_SIZE) history.shift()

    res.json({
      connected:  tag(statusXml, 'NewConnectionStatus') === 'Connected',
      externalIp: tag(ipXml, 'NewExternalIPAddress'),
      rxMbps:     parseFloat((rxRate * 8 / 1_000_000).toFixed(2)),
      txMbps:     parseFloat((txRate * 8 / 1_000_000).toFixed(2)),
      history:    history.map(h => ({ rx: h.rx, tx: h.tx })),
    })
  } catch (err: unknown) {
    const msg = err instanceof Error ? err.message : 'Unknown error'
    res.status(500).json({ error: msg })
  }
})

export default router