'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 app = express();

// ── Stabile Snapshot-API (vor dem Proxy registrieren!) ────────────────────────
// Für das Homing-Projekt: GET /api/snapshot/cam0 → JPEG
app.use('/api/snapshot', createSnapshotRouter(GO2RTC_URL));

// ── Health ────────────────────────────────────────────────────────────────────
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 });
  }
});

// ── Reverse-Proxy zu go2rtc ───────────────────────────────────────────────────
// Reicht nur die nötigen Pfade durch (go2rtc-Admin bleibt damit unerreichbar):
//   /api/ws          WebRTC/MSE-Signaling (WebSocket)
//   /api/frame.jpeg  Snapshots
//   /api/stream.*    MJPEG/MP4-Fallback
//   /api/streams     Stream-Liste
//   /video-rtc.js, /video-stream.js   go2rtc's offizieller Player
const go2rtcProxy = createProxyMiddleware({
  target:       GO2RTC_URL,
  changeOrigin: true,
  ws:           true,
  pathFilter:   ['/api/**', '/video-rtc.js', '/video-stream.js'],
  logger:       console,
});
app.use(go2rtcProxy);

// ── Eigener Viewer ─────────────────────────────────────────────────────────────
app.use(express.static(path.join(__dirname, 'public')));

// ── Start ───────────────────────────────────────────────────────────────────────
const server = http.createServer(app);
server.on('upgrade', go2rtcProxy.upgrade);   // WebSocket-Signaling durchreichen

server.listen(PORT, '0.0.0.0', () => {
  console.log(`AppRobotWebcam on http://0.0.0.0:${PORT}`);
  console.log(`  go2rtc backend:  ${GO2RTC_URL}`);
  console.log(`  Viewer:          http://0.0.0.0:${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'));