serviceWorker.js

// This optional code is used to register a service worker.
// register() is not called by default.

// This lets the app load faster on subsequent visits in production, and gives
// it offline capabilities. However, it also means that developers (and users)
// will only see deployed updates on subsequent visits to a page, after all the
// existing tabs open on the page have been closed, since previously cached
// resources are updated in the background.

// To learn more about the benefits of this model and instructions on how to
// opt-in, read https://bit.ly/CRA-PWA

const isLocalhost = Boolean(
  window.location.hostname === 'localhost' ||
  // [::1] is the IPv6 localhost address.
  window.location.hostname === '[::1]' ||
  // 127.0.0.0/8 are considered localhost for IPv4.
  window.location.hostname.match(
    /^127(?:\.(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}$/
  )
);

function urlBase64ToUint8Array(base64String) {
  const padding = '='.repeat((4 - base64String.length % 4) % 4);
  const base64 = (base64String + padding)
    .replace(/-/g, '+')
    .replace(/_/g, '/');

  const rawData = window.atob(base64);
  const outputArray = new Uint8Array(rawData.length);

  for (let i = 0; i < rawData.length; ++i) {
    outputArray[i] = rawData.charCodeAt(i);
  }
  return outputArray;
}


export function register(config) {
  let swRegistration = null, isSubscribed = false;

  function unsubscribeUser() {
    swRegistration.pushManager.getSubscription()
    .then(function(subscription) {
      if (subscription) {
        return subscription.unsubscribe();
      }
    })
    .catch(function(error) {
      console.log('Error unsubscribing', error);
    })
    .then(function() {
      //updateSubscriptionOnServer(null);
  
      console.log('User is unsubscribed.');
      isSubscribed = false;
  
    });
  }

  if ('serviceWorker' in navigator && 'PushManager' in window) {
    console.log('Service Worker and Push is supported');

    navigator.serviceWorker.register('sw.js')
      .then(function (swReg) {
        console.log('Service Worker is registered', swReg);
        swRegistration = swReg;

        // Set the initial subscription value
        swRegistration.pushManager.getSubscription()
          .then(function (subscription) {
            isSubscribed = !(subscription === null);

            if (isSubscribed) {
              console.log('User IS subscribed.');
              subscription.unsubscribe();
            } else {
              console.log('User is NOT subscribed.');
            }

            swRegistration.pushManager.subscribe({
              userVisibleOnly: true,
              applicationServerKey: urlBase64ToUint8Array(process.env.REACT_APP_EXAMPLE_PUSH_PUB)
            })
            .then(function(subscription) {
              console.log('User is subscribed.');
            
              //updateSubscriptionOnServer(subscription);
            
              isSubscribed = true;
              fetch(`${process.env.REACT_APP_URL_API}/api/v1/enlist`, {
                method: 'POST',
                body: JSON.stringify(subscription),
                headers: {
                  'content-type': 'application/json',
                  'authorization': `Bearer ${process.env.REACT_APP_EXAMPLE_JWT}`
                }
              });
            
            })
            .catch(function(err) {
              console.log('Failed to subscribe the user: ', err);
            });

          });


      })
      .catch(function (error) {
        console.error('Service Worker Error', error);
      });
  } else {
    console.warn('Push messaging is not supported');
    //pushButton.textContent = 'Push Not Supported';
  }




  //Removing crappy fb code
  // if (process.env.NODE_ENV === 'production' && 'serviceWorker' in navigator) {
  //   // The URL constructor is available in all browsers that support SW.
  //   const publicUrl = new URL(process.env.PUBLIC_URL, window.location.href);
  //   if (publicUrl.origin !== window.location.origin) {
  //     // Our service worker won't work if PUBLIC_URL is on a different origin
  //     // from what our page is served on. This might happen if a CDN is used to
  //     // serve assets; see https://github.com/facebook/create-react-app/issues/2374
  //     return;
  //   }

  //   window.addEventListener('load', () => {
  //     const swUrl = `${process.env.PUBLIC_URL}/service-worker.js`;

  //     if (isLocalhost) {
  //       // This is running on localhost. Let's check if a service worker still exists or not.
  //       checkValidServiceWorker(swUrl, config);

  //       // Add some additional logging to localhost, pointing developers to the
  //       // service worker/PWA documentation.
  //       navigator.serviceWorker.ready.then(() => {
  //         console.log(
  //           'This web app is being served cache-first by a service ' +
  //             'worker. To learn more, visit https://bit.ly/CRA-PWA'
  //         );
  //       });
  //     } else {
  //       // Is not localhost. Just register service worker
  //       registerValidSW(swUrl, config);
  //     }
  //   });
  // }
}

function registerValidSW(swUrl, config) {
  navigator.serviceWorker
    .register(swUrl)
    .then(registration => {
      registration.onupdatefound = () => {
        const installingWorker = registration.installing;
        if (installingWorker == null) {
          return;
        }
        installingWorker.onstatechange = () => {
          if (installingWorker.state === 'installed') {
            if (navigator.serviceWorker.controller) {
              // At this point, the updated precached content has been fetched,
              // but the previous service worker will still serve the older
              // content until all client tabs are closed.
              console.log(
                'New content is available and will be used when all ' +
                'tabs for this page are closed. See https://bit.ly/CRA-PWA.'
              );

              // Execute callback
              if (config && config.onUpdate) {
                config.onUpdate(registration);
              }
            } else {
              // At this point, everything has been precached.
              // It's the perfect time to display a
              // "Content is cached for offline use." message.
              console.log('Content is cached for offline use.');

              // Execute callback
              if (config && config.onSuccess) {
                config.onSuccess(registration);
              }
            }
          }
        };
      };
    })
    .catch(error => {
      console.error('Error during service worker registration:', error);
    });
}

function checkValidServiceWorker(swUrl, config) {
  // Check if the service worker can be found. If it can't reload the page.
  fetch(swUrl, {
    headers: { 'Service-Worker': 'script' }
  })
    .then(response => {
      // Ensure service worker exists, and that we really are getting a JS file.
      const contentType = response.headers.get('content-type');
      if (
        response.status === 404 ||
        (contentType != null && contentType.indexOf('javascript') === -1)
      ) {
        // No service worker found. Probably a different app. Reload the page.
        navigator.serviceWorker.ready.then(registration => {
          registration.unregister().then(() => {
            window.location.reload();
          });
        });
      } else {
        // Service worker found. Proceed as normal.
        registerValidSW(swUrl, config);
      }
    })
    .catch(() => {
      console.log(
        'No internet connection found. App is running in offline mode.'
      );
    });
}

export function unregister() {
  if ('serviceWorker' in navigator) {
    navigator.serviceWorker.ready
      .then(registration => {
        registration.unregister();
      })
      .catch(error => {
        console.error(error.message);
      });
  }
}