// A starter Garbo mini app's server, in Node.js 18 or newer (no packages): it serves
// index.html and checks the launch data your page sends (POST /api/me).
//
//   GARBO_APP_SECRET=<your app's secret> node server.mjs
//
// Then open http://localhost:8080 in a browser (it says "Not opened in Garbo"), or register
// your app as a draft with your computer's address (or a tunnel's) and open it in Garbo.

import { createServer } from 'node:http';
import { readFileSync } from 'node:fs';

import { checkHash } from '../check/node.mjs';

const PORT = Number(process.env.PORT ?? 8080);
const APP_SECRET = process.env.GARBO_APP_SECRET ?? '';
const page = readFileSync(new URL('./index.html', import.meta.url));

createServer(async (req, res) => {
  if (req.method === 'POST' && req.url === '/api/me') {
    let body = '';
    for await (const chunk of req) body += chunk;
    res.setHeader('Content-Type', 'application/json');
    try {
      // The hash proves Garbo made this launch data for your app, for this person, just now.
      const data = checkHash(body, APP_SECRET);
      // data.user.id is the person's id in your app: keep their cart, orders and so on under it.
      return res.end(JSON.stringify({ user: data.user, startParam: data.start_param ?? null }));
    } catch (error) {
      res.statusCode = 401;
      return res.end(JSON.stringify({ error: error.message }));
    }
  }
  res.setHeader('Content-Type', 'text/html; charset=utf-8');
  res.end(page);
}).listen(PORT, () => console.log(`Your mini app: http://localhost:${PORT}`));