'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) ─────────────────────────

// Stabile Snapshot-API für das Homing-Projekt
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 });
  }
});

// Gibt dem Viewer die go2rtc-Port-Nummer mit – Browser baut WS direkt zu go2rtc.
// Trennung HTTP (Node) / WebSocket (go2rtc) ist sauberer als ein fragiler WS-Proxy.
app.get('/config.json', (_req, res) => {
  res.json({ go2rtcPort: GO2RTC_PORT });
});

// ── 2. HTTP-Proxy zu go2rtc (nur für Script-Dateien und API ohne WS) ─────────
// /api/ws NICHT hier proxy-en – das macht der Browser direkt (s. viewer.js).
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 (eigener Viewer) ────────────────────────────────────
app.use(express.static(path.join(__dirname, 'public')));

// ── 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`);
});

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