const publicKey='BBfEJfOKDgKRvDnJHqGDdFElThShHKZfRYmch-HY2nlsvz6qpIKzc7KAARsKID6zdE_bC25orr6j_6MLtlFxw74';
					
						let isSubscribed = false;
						let swRegistration = null;
		
						function urlB64ToUint8Array(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;
						}
						
						function updateSubscriptionOnServer(subscription) {
							  
							  if(subscription !=null){
								  const key = subscription.getKey('p256dh');
								  const token = subscription.getKey('auth');
								  const contentEncoding = (PushManager.supportedContentEncodings || ['aesgcm'])[0];
								  
								  if('fetch' in window){
									  return fetch('ajax/webpush_register.php', {
										method: 'POST',
										body: JSON.stringify({
											endpoint: subscription.endpoint,
											publicKey: key ? btoa(String.fromCharCode.apply(null, new Uint8Array(key))) : null,
											authToken: token ? btoa(String.fromCharCode.apply(null, new Uint8Array(token))) : null,
											contentEncoding,
										}),
									  }).then(() => subscription);
								  }else{
									  
										var http = new XMLHttpRequest();
										var url = 'ajax/webpush_register.php';
										http.open('POST', url, true);
										
										//Send the proper header information along with the request
										http.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
										
										http.onreadystatechange = function() {//Call a function when the state changes.
											if(http.readyState == 4 && http.status == 200) {
												alert(http.responseText);
											}
										}
										
										http.send(JSON.stringify({
											endpoint: subscription.endpoint,
											publicKey: key ? btoa(String.fromCharCode.apply(null, new Uint8Array(key))) : null,
											authToken: token ? btoa(String.fromCharCode.apply(null, new Uint8Array(token))) : null,
											contentEncoding: contentEncoding,
										}));
									  
								  }
							  }else{
								  if('fetch' in window){
								  
									  return fetch('ajax/webpush_register.php', {
										method: 'POST',
										body: JSON.stringify({
											endpoint: null
										}),
									  }).then(() => subscription);
								  }else{
									  var http = new XMLHttpRequest();
										var url = 'ajax/webpush_register.php';
										http.open('POST', url, true);
										
										//Send the proper header information along with the request
										http.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
										
										http.onreadystatechange = function() {//Call a function when the state changes.
											if(http.readyState == 4 && http.status == 200) {
												alert(http.responseText);
											}
										}
										
										http.send(JSON.stringify({
											endpoint: subscription.endpoint,
											publicKey: key ? btoa(String.fromCharCode.apply(null, new Uint8Array(key))) : null,
											authToken: token ? btoa(String.fromCharCode.apply(null, new Uint8Array(token))) : null,
											contentEncoding,
										}));
								  }
							  }
						}
						
						function subscribeUser() {
							
							  const applicationServerKey = urlB64ToUint8Array(publicKey);
							  swRegistration.pushManager.subscribe({
									userVisibleOnly: true,
									applicationServerKey: applicationServerKey
							  })
							  .then(function(subscription) {
								
									updateSubscriptionOnServer(subscription);
								
									isSubscribed = true;
							  })
							  .catch(function(err) {
									console.log('Failed to subscribe the user: ', err.message);
									unsubscribeUser();
							  });
						}
						
						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);
							isSubscribed = false;
						  });
						}if ('serviceWorker' in navigator && 'PushManager' in window) {
                            navigator.serviceWorker.register('/serviceworker.js')
                                .then(function(swReg) {
                                
                                  swRegistration = swReg;
                                  
                                  
                                })
                        }