Show error dialogs instead of crashing if the database is read-only

Closes #292

app/Desktop/Arguments.cs

@@ -69,7 +69,7 @@ sealed class Arguments {
 						Log.Warn("Invalid concurrent downloads count: " + value);
 					}
 					else if (concurrentDownloads > 10) {
-						Log.Warn("Limiting concurrent downloads to 10");
+						Log.Warn("Limiting concurrent downloads to 10.");
 						ConcurrentDownloads = 10;
 					}
 					else {

app/Desktop/Common/DatabaseGui.cs

@@ -52,7 +52,7 @@ static class DatabaseGui {
 		} catch (DatabaseTooNewException ex) {
 			await Dialog.ShowOk(window, "Database Error", "Database '" + Path.GetFileName(path) + "' was opened in a newer version of DHT (database version " + ex.DatabaseVersion + ", app version " + ex.CurrentVersion + ").");
 		} catch (Exception ex) {
-			Log.Error(ex);
+			Log.Error("Could not open database file: " + path, ex);
 			await Dialog.ShowOk(window, "Database Error", "Database '" + Path.GetFileName(path) + "' could not be opened:" + ex.Message);
 		}
 		

app/Desktop/Discord/DiscordAppSettings.cs

@@ -42,8 +42,7 @@ static class DiscordAppSettings {
 			JsonObject settingsJson = await ReadSettingsJson();
 			return AreDevToolsEnabled(settingsJson);
 		} catch (Exception e) {
-			Log.Error("Cannot read settings file.");
+			Log.Error("Could not read settings file.", e);
-			Log.Error(e);
 			return null;
 		}
 	}
@@ -62,7 +61,7 @@ static class DiscordAppSettings {
 		} catch (JsonException) {
 			return SettingsJsonResult.InvalidJson;
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not read settings file.", e);
 			return SettingsJsonResult.ReadError;
 		}
 		
@@ -84,16 +83,14 @@ static class DiscordAppSettings {
 			
 			await WriteSettingsJson(json);
 		} catch (Exception e) {
-			Log.Error("An error occurred when writing settings file.");
+			Log.Error("Could not write settings file.", e);
-			Log.Error(e);
 			
 			if (File.Exists(JsonBackupFilePath)) {
 				try {
 					File.Move(JsonBackupFilePath, JsonFilePath, overwrite: true);
 					Log.Info("Restored settings file from backup.");
 				} catch (Exception e2) {
-					Log.Error("Cannot restore settings file from backup.");
+					Log.Error("Could not restore settings file from backup.", e2);
-					Log.Error(e2);
 				}
 			}
 			
@@ -103,8 +100,7 @@ static class DiscordAppSettings {
 		try {
 			File.Delete(JsonBackupFilePath);
 		} catch (Exception e) {
-			Log.Error("Cannot delete backup file.");
+			Log.Error("Could not delete backup file.", e);
-			Log.Error(e);
 		}
 		
 		return SettingsJsonResult.Success;

app/Desktop/Main/Controls/DownloadItemFilterPanelModel.cs

@@ -109,8 +109,7 @@ sealed partial class DownloadItemFilterPanelModel : IAsyncDisposable {
 				await setter.Set(SettingsKey.DownloadsMaximumSizeUnit, settings.MaximumSizeUnit.Name);
 			});
 		} catch (Exception e) {
-			Log.Error("Could not save download filter settings");
+			Log.Error("Could not save download filter settings.", e);
-			Log.Error(e);
 		}
 	}
 	

app/Desktop/Main/Controls/ServerConfigurationPanelModel.cs

@@ -62,7 +62,7 @@ sealed partial class ServerConfigurationPanelModel : IDisposable {
 		try {
 			await server.Start(ServerConfiguration.Port, ServerConfiguration.Token);
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not start internal server.", e);
 			await Dialog.ShowOk(window, "Internal Server Error", e.Message);
 		}
 		
@@ -76,7 +76,7 @@ sealed partial class ServerConfigurationPanelModel : IDisposable {
 		try {
 			await server.Stop();
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not stop internal server.", e);
 			await Dialog.ShowOk(window, "Internal Server Error", e.Message);
 		}
 		

app/Desktop/Main/MainWindowModel.cs

@@ -89,14 +89,21 @@ sealed partial class MainWindowModel : IAsyncDisposable {
 		try {
 			await state.Server.Start(ServerConfiguration.Port, ServerConfiguration.Token);
 		} catch (Exception ex) {
-			Log.Error(ex);
+			Log.Error("Could not start internal server.", ex);
 			await Dialog.ShowOk(window, "Internal Server Error", ex.Message);
 		}
 		
+		try {
 			mainContentScreenModel = new MainContentScreenModel(window, state);
 			mainContentScreenModel.DatabaseClosed += MainContentScreenModelOnDatabaseClosed;
-		
 			await mainContentScreenModel.Initialize();
+		} catch (Exception ex) {
+			Log.Error("Could not initialize content screen.", ex);
+			await Dialog.ShowOk(window, "Initialization Error", ex.Message);
+			await DisposeContent();
+			await DisposeState();
+			return;
+		}
 		
 		Title = Path.GetFileName(state.Db.Path) + " - " + DefaultTitle;
 		CurrentScreen = new MainContentScreen { DataContext = mainContentScreenModel };

app/Desktop/Main/Pages/DatabasePageModel.cs

@@ -84,7 +84,7 @@ sealed class DatabasePageModel {
 		try {
 			result = await ProgressDialog.Show(window, Title, async (dialog, callback) => await MergeWithDatabaseFromPaths(Db, paths, dialog, callback));
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not merge databases.", e);
 			await Dialog.ShowOk(window, Title, "Could not merge databases: " + e.Message);
 			return;
 		}
@@ -160,7 +160,7 @@ sealed class DatabasePageModel {
 		try {
 			result = await ProgressDialog.Show(window, Title, async (dialog, callback) => await ImportLegacyArchiveFromPaths(Db, paths, dialog, callback));
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not import legacy archives.", e);
 			await Dialog.ShowOk(window, Title, "Could not import legacy archives: " + e.Message);
 			return;
 		}
@@ -236,7 +236,7 @@ sealed class DatabasePageModel {
 					++successful;
 				}
 			} catch (Exception ex) {
-				Log.Error(ex);
+				Log.Error("Could not import file: " + path, ex);
 				await Dialog.ShowOk(dialog, dialogTitle, "File '" + Path.GetFileName(path) + "' could not be imported: " + ex.Message);
 			}
 		}
@@ -302,7 +302,7 @@ sealed class DatabasePageModel {
 		try {
 			await ProgressDialog.ShowIndeterminate(window, Title, "Vacuuming database...", _ => Db.Vacuum());
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not vacuum database.", e);
 			await Dialog.ShowOk(window, Title, "Could not vacuum database: " + e.Message);
 			return;
 		}

app/Desktop/Main/Pages/DownloadsPageModel.cs

@@ -92,7 +92,12 @@ sealed partial class DownloadsPageModel : IAsyncDisposable {
 		await FilterModel.Initialize();
 		
 		if (await state.Db.Settings.Get(SettingsKey.DownloadsAutoStart, defaultValue: false)) {
+			try {
 				await StartDownload();
+			} catch (Exception e) {
+				Log.Error("Could not automatically start downloads.", e);
+				await Dialog.ShowOk(window, "Database Error", "Could not automatically start downloads: " + e.Message);
+			}
 		}
 	}
 	
@@ -111,23 +116,43 @@ sealed partial class DownloadsPageModel : IAsyncDisposable {
 	
 	public async Task OnClickToggleDownload() {
 		IsToggleDownloadButtonEnabled = false;
-		
+		try {
 			if (IsDownloading) {
 				await StopDownload();
 			}
 			else {
+				try {
 					await StartDownload();
+				} catch (Exception e) {
+					Log.Error("Could not start downloads.", e);
+					await Dialog.ShowOk(window, "Database Error", "Could not start downloads: " + e.Message);
+					return;
+				}
 			}
 			
+			try {
 				await state.Db.Settings.Set(SettingsKey.DownloadsAutoStart, IsDownloading);
+			} catch (Exception e) {
+				Log.Error("Could not update auto-start setting in database.", e);
+			}
+		} finally {
 			IsToggleDownloadButtonEnabled = true;
 		}
+	}
 	
 	private async Task StartDownload() {
 		await state.Db.Downloads.MoveDownloadingItemsBackToQueue();
 		
-		IObservable<DownloadItem> finishedItems = await state.Downloader.Start(currentDownloadFilter = FilterModel.CreateFilter());
+		try {
+			currentDownloadFilter = FilterModel.CreateFilter();
+			IObservable<DownloadItem> finishedItems = await state.Downloader.Start(currentDownloadFilter);
 			finishedItemsSubscription = finishedItems.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnItemFinished);
+		} catch (Exception) {
+			finishedItemsSubscription?.Dispose();
+			finishedItemsSubscription = null;
+			currentDownloadFilter = null;
+			throw;
+		}
 		
 		OnDownloadStateChanged();
 	}
@@ -138,8 +163,8 @@ sealed partial class DownloadsPageModel : IAsyncDisposable {
 		
 		finishedItemsSubscription?.Dispose();
 		finishedItemsSubscription = null;
-		
 		currentDownloadFilter = null;
+		
 		OnDownloadStateChanged();
 	}
 	
@@ -155,12 +180,12 @@ sealed partial class DownloadsPageModel : IAsyncDisposable {
 	
 	public async Task OnClickRetryFailed() {
 		IsRetryingFailedDownloads = true;
-		
 		try {
 			await state.Db.Downloads.RetryFailed();
 			RecomputeDownloadStatistics();
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not retry failed downloads.", e);
+			await Dialog.ShowOk(window, "Retry Failed", "Could not retry failed downloads: " + e.Message);
 		} finally {
 			IsRetryingFailedDownloads = false;
 		}
@@ -212,7 +237,7 @@ sealed partial class DownloadsPageModel : IAsyncDisposable {
 				await state.Db.Vacuum();
 			});
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not delete orphaned downloads.", e);
 			await Dialog.ShowOk(window, Title, "Could not delete orphaned downloads: " + e.Message);
 		}
 	}
@@ -239,7 +264,7 @@ sealed partial class DownloadsPageModel : IAsyncDisposable {
 				return await exporter.Export(new ExportProgressReporter(callback));
 			});
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not export downloaded files.", e);
 			await Dialog.ShowOk(window, Title, "Could not export downloaded files: " + e.Message);
 			return;
 		}

app/Desktop/Main/Pages/TrackingPageModel.cs

@@ -146,7 +146,7 @@ sealed partial class TrackingPageModel {
 			await clipboard.SetTextAsync(script);
 			return true;
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not copy to clipboard.", e);
 			await Dialog.ShowOk(window, errorDialogTitle, "An error occurred while copying to clipboard.");
 			return false;
 		}

app/Desktop/Main/Pages/ViewerPageModel.cs

@@ -75,7 +75,7 @@ sealed partial class ViewerPageModel : IDisposable {
 				}
 			}
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not apply filters.", e);
 			await Dialog.ShowOk(window, "Apply Filters", "Could not apply filters: " + e.Message);
 		}
 	}

app/Desktop/Main/Screens/WelcomeScreenModel.cs

@@ -131,7 +131,7 @@ sealed partial class WelcomeScreenModel {
 			await Dialog.ShowOk(window, "Check Updates", "Request timed out.");
 			return;
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not check for updates.", e);
 			await Dialog.ShowOk(window, "Check Updates", "Error checking for updates: " + e.Message);
 			return;
 		}

app/Resources/Tracker/scripts/discord.js

@@ -67,7 +67,7 @@ class DISCORD {
 	/**
 	 * @type {function(String): MessageData}
 	 */
-	static #getMessages = WEBPACK.findFunction("getMessages");
+	static #getMessages = WEBPACK.findFunction("getMessages", [ "isLoadingMessages" ]);
 	
 	/**
 	 * @type {function(String): void}

app/Resources/Tracker/scripts/webpack.js

@@ -88,7 +88,7 @@ class WEBPACK {
 			return modules[0];
 		}
 		
-		console.error("[DHT] Cannot find module " + name + ", results found:", modules.length);
+		console.error("[DHT] Cannot find module " + name + ", results found:", modules.length, modules);
 		return null;
 	}
 	

app/Server/Download/DownloadExporter.cs

@@ -95,7 +95,7 @@ public sealed partial class DownloadExporter(IDatabaseFile db, string folderPath
 				} catch (FileAlreadyExistsException) {
 					success = false;
 				} catch (Exception e) {
-					Log.Error(e);
+					Log.Error("Could not export downloaded file: " + download.NormalizedUrl, e);
 					success = false;
 				}
 				

app/Server/Download/DownloaderTask.cs

@@ -2,6 +2,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Net;
 using System.Net.Http;
 using System.Reactive.Subjects;
 using System.Threading;
@@ -94,12 +95,10 @@ sealed class DownloaderTask : IAsyncDisposable {
 			} catch (TaskCanceledException e) when (e.InnerException is TimeoutException) {
 				await db.Downloads.AddDownload(item.ToFailure(), stream: null);
 				log.Error("Download timed out: " + item.DownloadUrl);
-			} catch (HttpRequestException e) {
-				await db.Downloads.AddDownload(item.ToFailure(e.StatusCode), stream: null);
-				log.Error(e);
 			} catch (Exception e) {
-				await db.Downloads.AddDownload(item.ToFailure(), stream: null);
+				HttpStatusCode? statusCode = e is HttpRequestException hre ? hre.StatusCode : null;
-				log.Error(e);
+				await db.Downloads.AddDownload(item.ToFailure(statusCode), stream: null);
+				log.Error("Could not download file: " + item.DownloadUrl, e);
 			} finally {
 				try {
 					finishedItemPublisher.OnNext(item);

app/Server/Endpoints/BaseEndpoint.cs

@@ -33,7 +33,7 @@ abstract class BaseEndpoint {
 				await response.WriteAsync(e.Message);
 			}
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not handle request.", e);
 			response.StatusCode = (int) HttpStatusCode.InternalServerError;
 		}
 	}

app/Server/Service/Middlewares/ServerLoggingMiddleware.cs

@@ -30,11 +30,11 @@ sealed class ServerLoggingMiddleware(RequestDelegate next) {
 		long elapsedMs = stopwatch.ElapsedMilliseconds;
 		
 		if (context.RequestAborted.IsCancellationRequested) {
-			Log.Debug("Request to " + request.GetEncodedPathAndQuery() + " (" + requestLength + " B) was cancelled after " + elapsedMs + " ms");
+			Log.Debug("Request to " + request.GetEncodedPathAndQuery() + " (" + requestLength + " B) was cancelled after " + elapsedMs + " ms.");
 		}
 		else {
 			int responseStatus = context.Response.StatusCode;
-			Log.Debug("Request to " + request.GetEncodedPathAndQuery() + " (" + requestLength + " B) returned " + responseStatus + ", took " + elapsedMs + " ms");
+			Log.Debug("Request to " + request.GetEncodedPathAndQuery() + " (" + requestLength + " B) returned " + responseStatus + ", took " + elapsedMs + " ms.");
 		}
 	}
 }

app/Server/Service/ServerManager.cs

@@ -88,7 +88,7 @@ public sealed class ServerManager {
 			throw;
 		}
 		
-		Log.Info("Server started");
+		Log.Info("Server started.");
 		
 		server = newServer;
 		
@@ -104,7 +104,7 @@ public sealed class ServerManager {
 		
 		Log.Info("Stopping server...");
 		await server.StopAsync();
-		Log.Info("Server stopped");
+		Log.Info("Server stopped.");
 		
 		server.Dispose();
 		server = null;

app/Utils/Logging/Log.cs

@@ -88,6 +88,11 @@ public sealed class Log {
 		LogLevel(ConsoleColor.Red, "ERROR", e.ToString());
 	}
 	
+	public void Error(string message, Exception e) {
+		Error(message);
+		Error(e);
+	}
+	
 	public Perf Start(string? context = null, [CallerMemberName] string callerMemberName = "") {
 		return Perf.Start(this, context, callerMemberName);
 	}