let deferredPrompt = null;
let installed = false;
let initiated = false;

export default {
	init() {
        initiated = true;
        window.addEventListener('beforeinstallprompt', (e) => {
            // Prevent Chrome 67 and earlier from automatically showing the prompt
            e.preventDefault();

            deferredPrompt = e;

            if (window.matchMedia('(display-mode: standalone)').matches) { 
                installed = true;
            } else {
                installed = false;
            }
      
            deferredPrompt.userChoice.then((choiceResult) => {
              if (choiceResult.outcome !== 'accepted') {
                installed = false;
              }
              deferredPrompt = null;
            });
        });

        window.addEventListener('appinstalled', () => {
            installed = true;
        });
	},
	isInstalled() {
        return initiated && installed;
  },
  install() {
      if (!installed) {
          deferredPrompt.prompt();
      }
  }
}