'use strict';

const express = require('express');
const http    = require('http');
const path    = require('path');
const { createProxyMiddleware } = require('http-proxy-middleware');
const { createSnapshotRouter }  = require('./src/snapshotService');

const PORT        = parseInt(process.env.PORT        ?? '8444', 10);
const GO2RTC_URL  = process.env.GO2RTC_URL  ?? 'http://localhost:1984';
const GO2RTC_PORT = parseInt(process.env.GO2RTC_PORT ?? '1984',  10);

const app = express();

// ── 1. Eigene Endpunkte (vor dem Proxy registrieren) ─────────────────────────

app.use('/api/snapshot', createSnapshotRouter(GO2RTC_URL));

app.get('/health', async (_req, res) => {
  try {
    const r = await fetch(`${GO2RTC_URL}/api/streams`);
    const streams = r.ok ? await r.json() : {};
    res.json({ status: r.ok ? 'ok' : 'degraded', cameras: Object.keys(streams) });
  } catch (err) {
    res.status(503).json({ status: 'down', error: err.message });
  }
});

app.get('/config.json', (_req, res) => {
  res.json({ go2rtcPort: GO2RTC_PORT });
});

// ── 2. HTTP-Proxy zu go2rtc ───────────────────────────────────────────────────
const go2rtcProxy = createProxyMiddleware({
  target:       GO2RTC_URL,
  changeOrigin: true,
  pathFilter:   ['/api', '/video-rtc.js', '/video-stream.js'],
  logger:       console,
  on: {
    error: (err, _req, res) => {
      console.error('[HPM] proxy error:', err.message);
      if (!res.headersSent) res.status(502).json({ error: 'go2rtc nicht erreichbar' });
    },
  },
});
app.use(go2rtcProxy);

// ── 3. Statische Dateien ──────────────────────────────────────────────────────
app.use(express.static(path.join(__dirname, 'public')));

// ── 4. go2rtc Stream-Monitor (server-seitiges Logging) ───────────────────────
// Pollt alle 5 s go2rtc /api/streams und loggt Änderungen.
// Sichtbar im Portainer-Log von AppRobotWebcam.
// Logt: Producer-Starts/-Stops, Consumer-Anzahl, Timeouts/Restarts.
//
// go2rtc /api/streams liefert z.B.:
// { "cam0": { "producers": [{"url":"...","state":"running"}], "consumers": [...] } }
//
const STREAM_POLL_MS = 5000;
let prevStreamState = {};

async function pollGo2rtcStreams() {
  try {
    const r = await fetch(`${GO2RTC_URL}/api/streams`);
    if (!r.ok) { console.warn(`[monitor] /api/streams → HTTP ${r.status}`); return; }
    const streams = await r.json();

    for (const [name, data] of Object.entries(streams)) {
      const producers  = data.producers ?? [];
      const consumers  = data.consumers ?? [];
      const nConsumers = consumers.length;
      const prev       = prevStreamState[name] ?? {};

      // Producer-Status
      for (let i = 0; i < producers.length; i++) {
        const p     = producers[i];
        const state = p.state ?? 'unknown';
        const key   = `${name}.p${i}`;
        const pPrev = prevStreamState[key];

        if (pPrev !== state) {
          if (state === 'running')  console.log(`[monitor][${name}] producer #${i} LÄUFT   (${p.url ?? ''})`);
          if (state === 'error')    console.error(`[monitor][${name}] producer #${i} FEHLER  (${p.url ?? ''})`);
          if (state === 'stop')     console.warn(`[monitor][${name}] producer #${i} GESTOPPT`);
          if (!['running','error','stop'].includes(state))
                                    console.log(`[monitor][${name}] producer #${i} state="${state}"`);
          prevStreamState[key] = state;
        }
      }

      // Consumer-Anzahl — nur loggen wenn sie sich ändert
      if (prev.nConsumers !== nConsumers) {
        console.log(`[monitor][${name}] consumers: ${prev.nConsumers ?? '?'} → ${nConsumers}`);
        prevStreamState[name] = { ...prev, nConsumers };
      }
    }

    // Streams die verschwunden sind (Timeout/Restart)
    for (const name of Object.keys(prevStreamState)) {
      if (name.includes('.')) continue;   // skip producer-state keys
      if (!streams[name]) {
        console.warn(`[monitor][${name}] Stream verschwunden aus go2rtc`);
        delete prevStreamState[name];
      }
    }

  } catch (err) {
    console.error('[monitor] go2rtc nicht erreichbar:', err.message);
  }
}

// ── Start ─────────────────────────────────────────────────────────────────────
const server = http.createServer(app);

server.listen(PORT, '0.0.0.0', () => {
  console.log(`AppRobotWebcam  http://0.0.0.0:${PORT}`);
  console.log(`  go2rtc HTTP:  ${GO2RTC_URL}`);
  console.log(`  go2rtc WS:    ws://[host]:${GO2RTC_PORT}  (Browser verbindet direkt)`);
  console.log(`  Viewer:       http://0.0.0.0:${PORT}/`);
  console.log(`  Snapshot API: http://0.0.0.0:${PORT}/api/snapshot/cam0`);
  console.log(`  Stream-Monitor: alle ${STREAM_POLL_MS / 1000}s → Portainer-Log`);

  // Ersten Poll nach 3 s (go2rtc braucht einen Moment zum Starten)
  setTimeout(() => {
    pollGo2rtcStreams();
    setInterval(pollGo2rtcStreams, STREAM_POLL_MS);
  }, 3000);
});

const shutdown = (sig) => {
  console.log(`\n${sig} – shutting down`);
  server.close(() => process.exit(0));
};
process.on('SIGINT',  () => shutdown('SIGINT'));
process.on('SIGTERM', () => shutdown('SIGTERM'));