{{flutter_js}}
{{flutter_build_config}}

const serviceWorkerVersion = '{{flutter_service_worker_version}}';

// 1. Let Flutter handle the service worker registration cleanly via its native loader
_flutter.loader.load({
  serviceWorkerSettings: {
    serviceWorkerVersion: serviceWorkerVersion
  }
});

// 2. Safely monitor the registration generated by Flutter without double-registering
if ('serviceWorker' in navigator) {
  navigator.serviceWorker.ready.then((reg) => {
    // If an updated worker is already waiting in the background
    if (reg.waiting) {
      showUpdatePrompt(reg);
    }

    // Listen for new updates found while the user has the app open
    reg.addEventListener('updatefound', () => {
      const newWorker = reg.installing;
      if (newWorker) {
        newWorker.addEventListener('statechange', () => {
          if (newWorker.state === 'installed' && navigator.serviceWorker.controller) {
            showUpdatePrompt(reg);
          }
        });
      }
    });
  });

  // Guard against infinite reload loops when the controller shifts
  let refreshing = false;
  navigator.serviceWorker.addEventListener('controllerchange', () => {
    if (!refreshing) {
      refreshing = true;
      window.location.reload();
    }
  });
}

function showUpdatePrompt(reg) {
  if (confirm('A new version of MIH is available. Refresh now to update?')) {
    reg.unregister().then(function () {
      window.location.reload(); // Unregister and reload to force clear the browser's cache
    });
  }
}