// main.jsx — This is the very first file React reads.
// It finds the <div id="root"> in index.html and injects the entire app into it.

import React from 'react'
import ReactDOM from 'react-dom/client'
import App from './App'
import './styles/global.css'

ReactDOM.createRoot(document.getElementById('root')).render(
  <React.StrictMode>
    <App />
  </React.StrictMode>
)

// ── PWA: Register service worker ─────────────────────────────
// Enables offline support, caching, and "Add to Home Screen" on Android/iOS.
// Only runs in production (Vercel) — skipped during local dev to avoid cache issues.
if ('serviceWorker' in navigator) {
  window.addEventListener('load', () => {
    navigator.serviceWorker
      .register('/sw.js')
      .then(reg => {
        console.log('✅ EduTrack SW registered:', reg.scope)

        // Check for SW updates every 60 minutes
        setInterval(() => reg.update(), 60 * 60 * 1000)
      })
      .catch(err => console.warn('SW registration failed:', err))
  })
}