server.js

const express = require('express');
const mongoose = require('mongoose');
const cors = require('cors');
require('dotenv').config();
const app = express();
const PORT = process.env.PORT || 3001;

// CORS configuration
const allowedOrigins = [process.env.REACT_FRONTEND_URL];

if (process.env.NODE_ENV === 'development') {
  allowedOrigins.push(process.env.REACT_FRONTEND_ALIAS);
}

app.use(cors({
  origin: function (origin, callback) {
    if (allowedOrigins.indexOf(origin) !== -1 || !origin) {
      callback(null, true);
    } else {
      callback(new Error('Not allowed by CORS'));
    }
  }
}));

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

// Database connection
mongoose.connect(process.env.MONGODB_URI, {
  useNewUrlParser: true,
  useUnifiedTopology: true,
})
.then(() => console.log('MongoDB connected'))
.catch((err) => console.log(err));

// API Routes
app.use('/api/users', require('./routes/users'));
app.use('/api/recipes', require('./routes/recipes'));
app.use('/api/categories', require('./routes/categories'));

app.listen(PORT, () => console.log(`Server running on port ${PORT}`));