#115 chore: added error handling for unhandled exceptions and a lifet…

…ime service

+ Added an ExtendedException which provides clues about how to solve a specific error
+ The lifetime service manages the lifetime of the web app. It loads the configuration and start the interfaces at the beginning, and stop the interfaces when it's shutting down
+ Renamed TrafficInfo.razor to RealTimeTraffic.razor for better understanding
+ Replaced async void methods with async Task for best practices
+ Fixed a bug with the interface property of AddInterface.razor. It must be set only once, and it was a getter only property which was being generated with every call

Linguard/Core/Exceptions/ExtendedException.cs

@@ -0,0 +1,16 @@
+namespace Linguard.Core.Exceptions; 
+
+public abstract class ExtendedException : Exception {
+    protected ExtendedException(IEnumerable<string> fixes) {
+        Fixes = fixes;
+    }
+    protected ExtendedException(string message, IEnumerable<string> fixes) : base(message) {
+        Fixes = fixes;
+    }
+    protected ExtendedException(string message, Exception innerException, IEnumerable<string> fixes) 
+        : base(message, innerException) {
+        Fixes = fixes;
+    }
+
+    public IEnumerable<string> Fixes { get; }
+}

Linguard/Core/Services/DefaultInterfaceGenerator.cs

@@ -19,7 +19,6 @@ public DefaultInterfaceGenerator(IConfigurationManager configurationManager, IWi
     }
 
     public Interface Generate() {
-
         return new Faker<Interface>()
             .RuleFor(i => i.Auto, true)
             .RuleFor(i => i.Description, f => f.Lorem.Sentence())

Linguard/Core/Services/Exceptions/WireguardException.cs

@@ -1,7 +1,15 @@
-namespace Linguard.Core.Services.Exceptions; 
+using Linguard.Core.Exceptions;
+using Linguard.Core.Utils;
 
-public class WireguardException : Exception {
-    public WireguardException() {}
-    public WireguardException(string message) : base(message) {}
-    public WireguardException(string message, Exception innerException) : base(message, innerException) {}
+namespace Linguard.Core.Services.Exceptions; 
+
+public class WireguardException : ExtendedException {
+
+    private static readonly string[] _fixes = {
+        "Verify that your Wireguard settings are correct.",
+        $"Ensure the user running {AssemblyInfo.Product} is able to run Wireguard as super user."
+    };
+    public WireguardException() : base(_fixes) {}
+    public WireguardException(string message) : base(message, _fixes) {}
+    public WireguardException(string message, Exception innerException) : base(message, innerException, _fixes) {}
 }

Linguard/Web/Pages/AddInterface.razor

@@ -14,7 +14,6 @@
 @inject IWireguardService _wireguardService
 @inject IWebService _webService;
 @inject NotificationService _notificationService
-@inject DialogService _dialogService
 @inject NavigationManager _navigationManager
 @inject IJSRuntime _js
 @inject AbstractValidator<Interface> _validator
@@ -26,7 +25,12 @@
     public Guid Id { get; set; }
 
     IConfiguration Configuration => _configurationManager.Configuration;
-    Interface Iface => _generator.Generate();
+    Interface Iface { get; set; }
+
+    protected override void OnInitialized() {
+        base.OnInitialized();
+        Iface = _generator.Generate();
+    }
 
 }
 <PageTitle>@($"{AssemblyInfo.Product} | {Title}")</PageTitle>

Linguard/Web/Pages/EditClient.razor

@@ -47,7 +47,7 @@
                 </RadzenCard>
             </RadzenAccordionItem>
             <RadzenAccordionItem Text="Traffic data" Icon="swap_vert">
-                <TrafficInfo Peer="Client"></TrafficInfo>
+                <RealTimeTraffic Peer="Client"></RealTimeTraffic>
             </RadzenAccordionItem>
         </Items>
     </RadzenAccordion>

Linguard/Web/Pages/EditInterface.razor

@@ -102,7 +102,7 @@
             </RadzenCard>
         </RadzenAccordionItem>
         <RadzenAccordionItem Text="Traffic data" Icon="swap_vert">
-            <TrafficInfo Peer="Iface"/>
+            <RealTimeTraffic Peer="Iface"/>
         </RadzenAccordionItem>
     </Items>
 </RadzenAccordion>
@@ -125,7 +125,7 @@
         _navigationManager.NavigateTo($"{nameof(Client).ToLower()}/{client.Id}");
     }
 
-    async void ConfirmRemoveWireguardPeer(IWireguardPeer peer) {
+    async Task ConfirmRemoveWireguardPeer(IWireguardPeer peer) {
         var peerType = peer.GetType().Name.ToLower();
         var remove = await _dialogService.Confirm(
             $"Are you sure you want to delete {peer.Name}? This cannot be undone.", 
@@ -174,7 +174,7 @@
             $"/{nameof(Interface)}/{Iface.Id}/add-{nameof(Client).ToLower()}");
     }
 
-    async void ShowQrCode(IWireguardPeer peer) {
+    async Task ShowQrCode(IWireguardPeer peer) {
         var qr = $"data:image/png;base64, {Convert.ToBase64String(_webService.GetQrCode(peer))}" ;
         await _dialogService.OpenAsync($"Configuration of {peer.Name}", ds =>
             @<div>

Linguard/Web/Pages/Wireguard.razor

@@ -198,7 +198,7 @@
         _navigationManager.NavigateTo($"/add-{nameof(Interface).ToLower()}");
     }
 
-    async void ConfirmRemoveWireguardPeer(IWireguardPeer peer) {
+    async Task ConfirmRemoveWireguardPeer(IWireguardPeer peer) {
         var peerType = peer.GetType().Name.ToLower();
         var remove = await _dialogService.Confirm(
             $"Are you sure you want to delete {peer.Name}? This cannot be undone.", 
@@ -247,7 +247,7 @@
         _interfacesGrid.Reload();
     }
 
-    async void ShowQrCode(IWireguardPeer peer) {
+    async Task ShowQrCode(IWireguardPeer peer) {
         var qr = $"data:image/png;base64, {Convert.ToBase64String(_webService.GetQrCode(peer))}" ;
         await _dialogService.OpenAsync($"Configuration of {peer.Name}", ds =>
             @<div>

Linguard/Web/Program.cs

@@ -1,3 +1,4 @@
+using System.Net;
 using FluentValidation;
 using Linguard.Core.Configuration;
 using Linguard.Core.Configuration.Serialization;
@@ -7,8 +8,8 @@
 using Linguard.Core.OS;
 using Linguard.Core.Services;
 using Linguard.Log;
-using Linguard.Web.Middlewares;
 using Linguard.Web.Services;
+using Microsoft.AspNetCore.Diagnostics;
 using QRCoder;
 using Radzen;
 using IConfiguration = Linguard.Core.Configuration.IConfiguration;
@@ -34,7 +35,7 @@
 
 builder.Services.AddTransient<IWebService, WebService>();
 builder.Services.AddTransient<QRCodeGenerator, QRCodeGenerator>();
-builder.Services.AddScoped<ConfigurationSetupMiddleware>();
+builder.Services.AddTransient<ILifetimeService, LifetimeService>();
 
 builder.Services.AddScoped<DialogService>();
 builder.Services.AddScoped<NotificationService>();
@@ -43,21 +44,34 @@
 
 var app = builder.Build();
 
+app.Lifetime.ApplicationStarted.Register(() => {
+    app.Services.GetService<ILifetimeService>()?.OnAppStarted();
+});
+
+app.Lifetime.ApplicationStopping.Register(() => {
+    app.Services.GetService<ILifetimeService>()?.OnAppStopping();
+});
+
+app.Lifetime.ApplicationStopped.Register(() => {
+    app.Services.GetService<ILifetimeService>()?.OnAppStopped();
+});
+
 // Configure the HTTP request pipeline.
-if (!app.Environment.IsDevelopment()) {
+if (app.Environment.IsDevelopment()) {
+    app.UseDeveloperExceptionPage();
+}
+else {
     app.UseExceptionHandler("/Error");
     // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
     app.UseHsts();
 }
 
-app.UseMiddleware<ConfigurationSetupMiddleware>();
 app.UseHttpsRedirection();
 
 app.UseStaticFiles();
 
 app.UseRouting();
-
 app.MapBlazorHub();
 app.MapFallbackToPage("/_Host");
 
-app.Run();
+app.Run();

Linguard/Web/Services/ILifetimeService.cs

@@ -0,0 +1,7 @@
+namespace Linguard.Web.Services; 
+
+public interface ILifetimeService {
+    void OnAppStarted();
+    void OnAppStopping();
+    void OnAppStopped();
+}

Linguard/Web/Services/IWebService.cs

@@ -3,9 +3,9 @@
 namespace Linguard.Web.Services; 
 
 public interface IWebService {
-    void Download(string data, string filename);
-    void DownloadConfiguration();
-    void DownloadWireguardModel(IWireguardPeer peer);
+    Task Download(string data, string filename);
+    Task DownloadConfiguration();
+    Task DownloadWireguardModel(IWireguardPeer peer);
     void RemoveWireguardModel(IWireguardPeer peer);
     byte[] GetQrCode(IWireguardPeer peer);
 }