import express from 'express';
import path from 'path';
import cors from 'cors';
import { fileURLToPath } from 'url';
import { createProxyMiddleware } from 'http-proxy-middleware';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

const app = express();
const PORT = process.env.PORT || 3000;
const BACKEND_URL = process.env.BACKEND_URL || 'http://backend:3001';

// Enable CORS for API calls
app.use(cors({
  origin: process.env.CORS_ORIGIN || '*',
  credentials: true
}));

// Proxy API requests to backend
app.use('/api', createProxyMiddleware({
  target: BACKEND_URL,
  changeOrigin: true,
  logLevel: 'info',
  onError: (err, req, res) => {
    console.error('Proxy error:', err.message);
    res.status(500).json({ error: 'Backend service unavailable' });
  },
  onProxyReq: (proxyReq, req, res) => {
    console.log(`Proxying ${req.method} ${req.path} to ${BACKEND_URL}`);
  }
}));

// Serve static files from dist directory
app.use(express.static(path.join(__dirname, 'dist')));

// Handle SPA routing - serve index.html for all routes
app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, 'dist', 'index.html'));
});

app.listen(PORT, () => {
  console.log(`Frontend server running on port ${PORT}`);
  console.log(`Serving from: ${path.join(__dirname, 'dist')}`);
});