const express = require('express');
const proxy = require('express-http-proxy');
const bodyParser = require('body-parser');
const rateLimit = require('express-rate-limit');
const requestIp = require('request-ip');

const app = express();


const proxyKey = process.env.PROXY_KEY; // Your secret proxy key
const adminKey = process.env.ADMIN_KEY; // Your admin key for securing the proxy key endpoint
const port = 7860;
const baseUrl = getExternalUrl(process.env.SPACE_ID);

app.use(bodyParser.json({ limit: '50mb' }));
app.set('trust proxy', 1);

// Rate limiting middleware
const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 50, // limit each IP to 50 requests per windowMs
  keyGenerator: (req, res) => req.ip,
  handler: (req, res) => {
    res.status(429).json({
      message: "Too many requests. Please try again later. You can retry after 15 minutes.",
    });
  },
});

// Apply the rate limiter to all requests
app.use(limiter);


// Endpoint to get the proxy key
app.get('/get-proxy-key', (req, res) => {
  const providedAdminKey = req.headers['admin-key'];
  
  if (providedAdminKey && providedAdminKey === adminKey) {
    res.json({ proxyKey });
  } else {
    res.status(403).json({ error: 'Forbidden' });
  }
});


// Health check endpoint
app.get("/", (req, res) => {
  res.send(`This is your OpenAI Reverse Proxy URL: ${baseUrl}`);
});

// Helper function to get the external URL
function getExternalUrl(spaceId) {
  try {
    const [username, spacename] = spaceId.split("/");
    return `https://${username}-${spacename.replace(/_/g, "-")}.hf.space/api/v1`;
  } catch (e) {
    return "";
  }
}

// Start the server
app.listen(port, () => {
  console.log(`Reverse proxy server running on ${baseUrl}`);
});