'use strict';

const express = require('express');
const http = require('http');
const { WebSocketServer } = require('ws');
const path = require('path');
const { detectDevices } = require('./src/deviceDetect');
const { VideoStream } = require('./src/videoStream');
const { createSnapshotRouter } = require('./src/snapshotService');

const PORT = parseInt(process.env.PORT ?? '8080', 10);

function buildStreams() {
  const devices = detectDevices();
  console.log(`Detected ${devices.length} camera(s):`, devices);

  return devices.map((device, idx) => new VideoStream(device, {
    name: `cam${idx}`,
    width:   parseInt(process.env[`CAM${idx}_WIDTH`]   ?? '640',  10),
    height:  parseInt(process.env[`CAM${idx}_HEIGHT`]  ?? '480',  10),
    fps:     parseInt(process.env[`CAM${idx}_FPS`]     ?? '30',   10),
    quality: parseInt(process.env[`CAM${idx}_QUALITY`] ?? '5',    10),
  }));
}

function main() {
  const streams = buildStreams();

  // Start all streams eagerly – first client gets immediate frame
  streams.forEach(s => s.start());

  const app = express();

  app.use(express.static(path.join(__dirname, 'public')));
  app.use('/api/snapshot', createSnapshotRouter(streams));

  app.get('/health', (_req, res) => {
    res.json({
      status: 'ok',
      cameras: streams.map((s, i) => ({
        id: `cam${i}`,
        device: s.device,
        running: s.isRunning,
        clients: s.clientCount,
        hasFrame: s.latestFrame !== null,
      })),
    });
  });

  const server = http.createServer(app);
  const wss = new WebSocketServer({ noServer: true });

  server.on('upgrade', (req, socket, head) => {
    const match = req.url?.match(/^\/ws\/cam(\d+)$/);
    if (!match) { socket.destroy(); return; }

    const idx = parseInt(match[1], 10);
    if (!streams[idx]) { socket.destroy(); return; }

    wss.handleUpgrade(req, socket, head, (ws) => {
      const stream = streams[idx];
      stream.addClient(ws);
      ws.on('close', () => stream.removeClient(ws));
      ws.on('error', () => stream.removeClient(ws));
    });
  });

  server.listen(PORT, '0.0.0.0', () => {
    console.log(`AppRobotWebcam on http://0.0.0.0:${PORT}`);
    streams.forEach((s, i) => {
      console.log(`  ws://0.0.0.0:${PORT}/ws/cam${i}  →  ${s.device}`);
      console.log(`  http://0.0.0.0:${PORT}/api/snapshot/cam${i}`);
    });
  });

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

main();