#!/usr/bin/env node
/**
 * Generate a pairing QR code for JTL-POS.
 *
 * Usage:
 *   node scripts/create-pairing-qr.mjs <host-ip>
 *   npm run qr -- 192.168.1.50
 *
 * Reads PORT / PAIRING_CODE from .env and the TLS cert from certs/cert.pem.
 */
import fs from 'node:fs';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

import dotenv from 'dotenv';
import QRCode from 'qrcode';

const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), '..');
dotenv.config({ path: path.join(root, '.env') });

const host = process.argv[2];
if (!host) {
  console.error('Usage: node scripts/create-pairing-qr.mjs <host-ip>');
  process.exit(1);
}

const port = String(process.env.PORT || '4443');
const pin = String(process.env.PAIRING_CODE || '307018');
const certPath = path.join(root, 'certs', 'cert.pem');
// Compact: base64 DER only (no PEM headers / line wraps) — client can re-wrap if needed
const cert = fs
  .readFileSync(certPath, 'utf8')
  .replace(/-----BEGIN CERTIFICATE-----/g, '')
  .replace(/-----END CERTIFICATE-----/g, '')
  .replace(/\s+/g, '');

const payload = {
  v: 1,
  host,
  port,
  pin,
  cert,
};

const content = JSON.stringify(payload);

const outDir = path.join(root, 'certs');
const pngPath = path.join(outDir, 'pairing-qr.png');
const jsonPath = path.join(outDir, 'pairing-qr.json');

const qrOpts = {
  errorCorrectionLevel: 'L', // ~7% recovery — smallest size for the payload
  margin: 1,
};

const qr = QRCode.create(content, qrOpts);
// Scale by module count so fewer modules actually looks smaller (not stretched to 512)
const modulePx = 4;
const width = qr.modules.size * modulePx;

await QRCode.toFile(pngPath, content, {
  ...qrOpts,
  type: 'png',
  width,
});
fs.writeFileSync(jsonPath, `${JSON.stringify(payload, null, 2)}\n`);

console.log(await QRCode.toString(content, { type: 'terminal', small: true, ...qrOpts }));
console.log(content);
console.log(`host=${host} port=${port} pin=${pin}`);
console.log(`QR version=${qr.version} modules=${qr.modules.size} png=${width}px`);
console.log(`Wrote ${pngPath}`);
console.log(`Wrote ${jsonPath}`);