import express from 'express';
import cors from 'cors';
import { disconnectDB } from './db';
import { startSyncScheduler, stopSyncScheduler } from './jobs/sync-scheduler';

// Import routes
import usersRoutes from './routes/users.routes';
import gradesRoutes from './routes/grades.routes';
import statsRoutes from './routes/stats.routes';

const app = express();
const PORT = process.env.PORT || 4000;

// Middleware
app.use(cors());
app.use(express.json());

// Health check
app.get('/health', (req, res) => {
  res.json({
    status: 'ok',
    message: 'Skyward Backend API is running',
    timestamp: new Date().toISOString(),
  });
});

// Routes
app.use('/api/users', usersRoutes);
app.use('/api', gradesRoutes);
app.use('/api/stats', statsRoutes);

// 404 handler
app.use((req, res) => {
  res.status(404).json({
    success: false,
    error: 'Route not found',
  });
});

// Start server
app.listen(PORT, () => {
  console.log(`\n🚀 Skyward Backend API running on port ${PORT}`);
  console.log(`📡 Health check: http://localhost:${PORT}/health\n`);
  
  console.log('Available endpoints:');
  console.log('  POST   /api/users/register');
  console.log('  GET    /api/users');
  console.log('  DELETE /api/users/:username');
  console.log('  GET    /api/users/:username/grades');
  console.log('  GET    /api/users/:username/classes');
  console.log('  GET    /api/users/:username/classes/:category/assignments');
  console.log('  GET    /api/users/:username/history');
  console.log('  POST   /api/sync/manual');
  console.log('  GET    /api/stats/overall');
  console.log('  GET    /api/stats/users/:username');
  console.log('  GET    /api/stats/users/:username/classes/:category\n');
  
  // Start background sync scheduler
  startSyncScheduler();
});

// Graceful shutdown
process.on('SIGINT', async () => {
  console.log('\n\n[Server] Shutting down gracefully...');
  stopSyncScheduler();
  await disconnectDB();
  process.exit(0);
});

process.on('SIGTERM', async () => {
  console.log('\n\n[Server] Shutting down gracefully...');
  stopSyncScheduler();
  await disconnectDB();
  process.exit(0);
});