const express = require('express');
const http = require('http');
const { WebSocketServer } = require('ws');
const cors = require('cors');
const path = require('path');

const db = require('./db');
const pdfRoutes = require('./routes/pdfs');
const conversationRoutes = require('./routes/conversations');
const chatRoutes = require('./routes/chat');
const progressRoutes = require('./routes/progress');
const notesRoutes = require('./routes/notes');
const modelRoutes = require('./routes/models');
const configRoutes = require('./routes/config');

const app = express();
const server = http.createServer(app);
const PORT = process.env.PORT || 3001;

// Middleware
app.use(cors({
  origin: ['http://localhost:5173', 'http://localhost:3001'],
  credentials: true,
}));
app.use(express.json({ limit: '10mb' }));
app.use(express.urlencoded({ extended: true }));

// API Routes
app.use('/api/pdfs', pdfRoutes);
app.use('/api/conversations', conversationRoutes);
app.use('/api/chat', chatRoutes);
app.use('/api/progress', progressRoutes);
app.use('/api/notes', notesRoutes);
app.use('/api/models', modelRoutes);
app.use('/api/config', configRoutes);

// Serve React build in production
const clientDist = path.resolve(__dirname, '..', 'client', 'dist');
app.use(express.static(clientDist));
app.get('*', (req, res, next) => {
  if (req.path.startsWith('/api')) return next();
  res.sendFile(path.join(clientDist, 'index.html'), (err) => {
    if (err) next();
  });
});

// WebSocket server
const wss = new WebSocketServer({ server });
wss.on('connection', (ws) => {
  ws.on('message', (message) => {
    // Echo — extensible for real-time notifications
  });
  try {
    ws.send(JSON.stringify({ type: 'connected', message: 'StudyOS WebSocket connected' }));
  } catch (err) {
    console.error('[ws] send error:', err.message);
  }
});

async function start() {
  await db.initDB();
  server.listen(PORT, () => {
    console.log(`StudyOS server running on http://localhost:${PORT}`);
    console.log(`WebSocket server running on ws://localhost:${PORT}`);
  });
}

start().catch(err => {
  console.error('Failed to start server:', err);
  process.exit(1);
});