const express = require('express');
const { Pool } = require('pg');
const redis = require('redis');
const path = require('path');

const app = express();
const PORT = process.env.PORT || 3000;

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

// PostgreSQL connection
const pool = new Pool({
  host: process.env.POSTGRES_HOST || 'postgres',
  port: process.env.POSTGRES_PORT || 5432,
  user: process.env.POSTGRES_USER || 'postgres',
  password: process.env.POSTGRES_PASSWORD || 'postgres',
  database: process.env.POSTGRES_DB || 'postgres'
});

// Redis connection
const redisClient = redis.createClient({
  socket: {
    host: process.env.REDIS_HOST || 'redis',
    port: process.env.REDIS_PORT || 6379
  }
});

redisClient.connect().catch(console.error);

pool.query('SELECT NOW()', (err, res) => {
  if (err) {
    console.error('PostgreSQL connection error:', err);
  } else {
    console.log('PostgreSQL connected at:', res.rows[0].now);
  }
});

redisClient.on('connect', () => console.log('Redis connected'));
redisClient.on('error', (err) => console.error('Redis error:', err));

// --- API Routes ---

// Health check
app.get('/health', async (req, res) => {
  try {
    const pgResult = await pool.query('SELECT NOW()');
    await redisClient.ping();
    res.json({
      status: 'healthy',
      postgres: 'connected',
      redis: 'connected',
      timestamp: pgResult.rows[0].now,
      version: process.env.APP_VERSION || '1.0.0'
    });
  } catch (error) {
    res.status(500).json({ status: 'unhealthy', error: error.message });
  }
});

// Example API endpoint — replace with your own
app.get('/api/status', async (req, res) => {
  try {
    const pgResult = await pool.query('SELECT NOW()');
    res.json({ ok: true, time: pgResult.rows[0].now });
  } catch (error) {
    res.status(500).json({ ok: false, error: error.message });
  }
});

// --- Serve React Frontend ---
// In production, serve the built React app from client/dist
const clientDist = path.join(__dirname, 'client', 'dist');
app.use(express.static(clientDist));

// SPA fallback — all non-API routes serve index.html so React Router works
app.get('*', (req, res, next) => {
  if (req.path.startsWith('/api/') || req.path === '/health') return next();
  res.sendFile(path.join(clientDist, 'index.html'));
});

app.listen(PORT, '0.0.0.0', () => {
  console.log(`Server running on port ${PORT}`);
});

// Export for testing
module.exports = { app, pool, redisClient };