server.js

import express from 'express';
import cors from 'cors';
import fetch from 'node-fetch';
import dotenv from 'dotenv';

dotenv.config();

const app = express();
app.use(cors());
app.use(express.json());

const GROQ_API_KEY = process.env.GROQ_API_KEY;
const GROQ_API_URL = 'https://api.groq.com/openai/v1/chat/completions';

// Rate limiting simple
const requestCounts = new Map();
const RATE_LIMIT = 10; // 10 requests per minute per IP
const RATE_WINDOW = 60000; // 1 minute

function checkRateLimit(ip) {
  const now = Date.now();
  if (!requestCounts.has(ip)) {
    requestCounts.set(ip, []);
  }
  
  const requests = requestCounts.get(ip).filter(t => now - t < RATE_WINDOW);
  if (requests.length >= RATE_LIMIT) {
    return false;
  }
  
  requests.push(now);
  requestCounts.set(ip, requests);
  return true;
}

app.post('/api/generate', async (req, res) => {
  try {
    const ip = req.ip;
    
    // Rate limiting
    if (!checkRateLimit(ip)) {
      return res.status(429).json({ error: 'Demasiadas solicitudes. Espera 1 minuto.' });
    }

    const { systemPrompt, userPrompt } = req.body;

    if (!systemPrompt || !userPrompt) {
      return res.status(400).json({ error: 'Faltan parámetros requeridos.' });
    }

    // Validate input length (prevent abuse)
    if (systemPrompt.length > 2000 || userPrompt.length > 2000) {
      return res.status(400).json({ error: 'El prompt es demasiado largo.' });
    }

    const response = await fetch(GROQ_API_URL, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${GROQ_API_KEY}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify({
        model: 'mixtral-8x7b-32768', // Fast & free model
        messages: [
          { role: 'system', content: systemPrompt },
          { role: 'user', content: userPrompt }
        ],
        max_tokens: 1000,
        temperature: 0.7,
      }),
    });

    if (!response.ok) {
      const error = await response.json();
      console.error('Groq API Error:', error);
      return res.status(response.status).json({ 
        error: error.error?.message || 'Error en la API de Groq' 
      });
    }

    const data = await response.json();
    const content = data.choices?.[0]?.message?.content || '';

    res.json({ content });
  } catch (error) {
    console.error('Server Error:', error);
    res.status(500).json({ error: 'Error interno del servidor.' });
  }
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
  console.log(`Servidor ejecutándose en puerto ${PORT}`);
});