Release v41.2

Closes #256

app/.idea/.idea.DiscordHistoryTracker/.idea/avalonia.xml

@@ -9,15 +9,15 @@
         <entry key="Desktop/Dialogs/Progress/ProgressDialog.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Dialogs/TextBox/TextBoxDialog.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/AboutWindow.axaml" value="Desktop/Desktop.csproj" />
-        <entry key="Desktop/Main/Controls/AttachmentFilterPanel.axaml" value="Desktop/Desktop.csproj" />
+        <entry key="Desktop/Main/Controls/DownloadItemFilterPanel.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Controls/MessageFilterPanel.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Controls/ServerConfigurationPanel.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Controls/StatusBar.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/MainWindow.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Pages/AdvancedPage.axaml" value="Desktop/Desktop.csproj" />
-        <entry key="Desktop/Main/Pages/AttachmentsPage.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Pages/DatabasePage.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Pages/DebugPage.axaml" value="Desktop/Desktop.csproj" />
+        <entry key="Desktop/Main/Pages/DownloadsPage.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Pages/TrackingPage.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Pages/ViewerPage.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Screens/MainContentScreen.axaml" value="Desktop/Desktop.csproj" />
@@ -25,4 +25,4 @@
       </map>
     </option>
   </component>
-</project>
+</project>

app/Desktop/App.axaml.cs

@@ -1,4 +1,3 @@
-using System;
 using Avalonia;
 using Avalonia.Controls.ApplicationLifetimes;
 using Avalonia.Markup.Xaml;
@@ -13,7 +12,7 @@ sealed class App : Application {
 
 	public override void OnFrameworkInitializationCompleted() {
 		if (ApplicationLifetime is IClassicDesktopStyleApplicationLifetime desktop) {
-			desktop.MainWindow = new MainWindow(new Arguments(desktop.Args ?? Array.Empty<string>()));
+			desktop.MainWindow = new MainWindow(Program.Arguments);
 		}
 
 		base.OnFrameworkInitializationCompleted();

app/Desktop/Arguments.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using DHT.Utils.Logging;
 
 namespace DHT.Desktop;
@@ -6,29 +7,37 @@ namespace DHT.Desktop;
 sealed class Arguments {
 	private static readonly Log Log = Log.ForType<Arguments>();
 
-	public static Arguments Empty => new(Array.Empty<string>());
+	private const int FirstArgument = 1;
 
+	public static Arguments Empty => new (Array.Empty<string>());
+
+	public bool Console { get; }
 	public string? DatabaseFile { get; }
 	public ushort? ServerPort { get; }
 	public string? ServerToken { get; }
+	public byte? ConcurrentDownloads { get; }
 
-	public Arguments(string[] args) {
+	public Arguments(IReadOnlyList<string> args) {
-		for (int i = 0; i < args.Length; i++) {
+		for (int i = FirstArgument; i < args.Count; i++) {
 			string key = args[i];
 
 			switch (key) {
 				case "-debug":
 					Log.IsDebugEnabled = true;
 					continue;
+
+				case "-console":
+					Console = true;
+					continue;
 			}
 
 			string value;
 
-			if (i == 0 && !key.StartsWith('-')) {
+			if (i == FirstArgument && !key.StartsWith('-')) {
 				value = key;
 				key = "-db";
 			}
-			else if (i >= args.Length - 1) {
+			else if (i >= args.Count - 1) {
 				Log.Warn("Missing value for command line argument: " + key);
 				continue;
 			}
@@ -42,11 +51,11 @@ sealed class Arguments {
 					continue;
 
 				case "-port": {
-					if (ushort.TryParse(value, out var port)) {
+					if (!ushort.TryParse(value, out var port)) {
-						ServerPort = port;
+						Log.Warn("Invalid port number: " + value);
 					}
 					else {
-						Log.Warn("Invalid port number: " + value);
+						ServerPort = port;
 					}
 
 					continue;
@@ -55,6 +64,20 @@ sealed class Arguments {
 				case "-token":
 					ServerToken = value;
 					continue;
+				
+				case "-concurrentdownloads":
+					if (!ulong.TryParse(value, out var concurrentDownloads) || concurrentDownloads == 0) {
+						Log.Warn("Invalid concurrent downloads count: " + value);
+					}
+					else if (concurrentDownloads > 10) {
+						Log.Warn("Limiting concurrent downloads to 10");
+						ConcurrentDownloads = 10;
+					}
+					else {
+						ConcurrentDownloads = (byte) concurrentDownloads;
+					}
+					
+					continue;
 
 				default:
 					Log.Warn("Unknown command line argument: " + key);

app/Desktop/Common/BytesValueConverter.cs

@@ -19,17 +19,17 @@ sealed class BytesValueConverter : IValueConverter {
 		}
 	}
 
-	private static readonly Unit[] Units = {
+	private static readonly Unit[] Units = [
-		new ("B", decimalPlaces: 0),
+		new Unit("B", decimalPlaces: 0),
-		new ("kB", decimalPlaces: 0),
+		new Unit("kB", decimalPlaces: 0),
-		new ("MB", decimalPlaces: 1),
+		new Unit("MB", decimalPlaces: 1),
-		new ("GB", decimalPlaces: 1),
+		new Unit("GB", decimalPlaces: 1),
-		new ("TB", decimalPlaces: 1)
+		new Unit("TB", decimalPlaces: 1)
-	};
+	];
 
 	private const int Scale = 1000;
 
-	private static string Convert(ulong size) {
+	public static string Convert(ulong size) {
 		int power = size == 0L ? 0 : (int) Math.Log(size, Scale);
 		int unit = power >= Units.Length ? Units.Length - 1 : power;
 		return Units[unit].Format(unit == 0 ? size : size / Math.Pow(Scale, unit));

app/Desktop/Common/DatabaseGui.cs

@@ -9,6 +9,7 @@ using DHT.Desktop.Dialogs.Message;
 using DHT.Server.Database;
 using DHT.Server.Database.Exceptions;
 using DHT.Server.Database.Sqlite;
+using DHT.Server.Database.Sqlite.Schema;
 using DHT.Utils.Logging;
 
 namespace DHT.Desktop.Common;
@@ -18,9 +19,9 @@ static class DatabaseGui {
 
 	private const string DatabaseFileInitialName = "archive.dht";
 
-	private static readonly IReadOnlyList<FilePickerFileType> DatabaseFileDialogFilter = new List<FilePickerFileType> {
+	private static readonly IReadOnlyList<FilePickerFileType> DatabaseFileDialogFilter = [
-		FileDialogs.CreateFilter("Discord History Tracker Database", new [] { "dht" })
+		FileDialogs.CreateFilter("Discord History Tracker Database", ["dht"])
-	};
+	];
 
 	public static async Task<string[]> NewOpenDatabaseFilesDialog(Window window, string? suggestedDirectory) {
 		return await window.StorageProvider.OpenFiles(new FilePickerOpenOptions {
@@ -41,11 +42,11 @@ static class DatabaseGui {
 		});
 	}
 
-	public static async Task<IDatabaseFile?> TryOpenOrCreateDatabaseFromPath(string path, Window window, Func<Task<bool>> checkCanUpgradeDatabase) {
+	public static async Task<IDatabaseFile?> TryOpenOrCreateDatabaseFromPath(string path, Window window, ISchemaUpgradeCallbacks schemaUpgradeCallbacks) {
 		IDatabaseFile? file = null;
 
 		try {
-			file = await SqliteDatabaseFile.OpenOrCreate(path, checkCanUpgradeDatabase);
+			file = await SqliteDatabaseFile.OpenOrCreate(path, schemaUpgradeCallbacks);
 		} catch (InvalidDatabaseVersionException ex) {
 			await Dialog.ShowOk(window, "Database Error", "Database '" + Path.GetFileName(path) + "' appears to be corrupted (invalid version: " + ex.Version + ").");
 		} catch (DatabaseTooNewException ex) {

app/Desktop/Desktop.csproj

@@ -9,6 +9,7 @@
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
     <ApplicationIcon>./Resources/icon.ico</ApplicationIcon>
+    <AvaloniaUseCompiledBindingsByDefault>true</AvaloniaUseCompiledBindingsByDefault>
     <CheckForOverflowUnderflow>true</CheckForOverflowUnderflow>
     <SatelliteResourceLanguages>en</SatelliteResourceLanguages>
   </PropertyGroup>
@@ -20,7 +21,9 @@
     <PackageReference Include="Avalonia.Desktop" Version="11.0.6" />
     <PackageReference Include="Avalonia.Diagnostics" Version="11.0.6" Condition=" '$(Configuration)' == 'Debug' " />
     <PackageReference Include="Avalonia.Fonts.Inter" Version="11.0.6" />
+    <PackageReference Include="Avalonia.ReactiveUI" Version="11.0.6" />
     <PackageReference Include="Avalonia.Themes.Fluent" Version="11.0.6" />
+    <PackageReference Include="CommunityToolkit.Mvvm" Version="999.0.0-build.0.g0d941a6a62" />
   </ItemGroup>
   
   <ItemGroup>
@@ -29,10 +32,6 @@
   
   <ItemGroup>
     <Compile Include="..\Version.cs" Link="Version.cs" />
-    <Compile Update="Dialogs\TextBox\TextBoxDialog.axaml.cs">
-      <DependentUpon>CheckBoxDialog.axaml</DependentUpon>
-      <SubType>Code</SubType>
-    </Compile>
   </ItemGroup>
   
   <ItemGroup>

app/Desktop/Dialogs/CheckBox/CheckBoxDialog.axaml

@@ -5,6 +5,7 @@
         xmlns:namespace="clr-namespace:DHT.Desktop.Dialogs.CheckBox"
         mc:Ignorable="d" d:DesignWidth="500"
         x:Class="DHT.Desktop.Dialogs.CheckBox.CheckBoxDialog"
+        x:DataType="namespace:CheckBoxDialogModel"
         Title="{Binding Title}"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
         Width="500" SizeToContent="Height" CanResize="False"
@@ -37,7 +38,7 @@
             <ItemsRepeater ItemsSource="{Binding Items}">
                 <ItemsRepeater.ItemTemplate>
                     <DataTemplate>
-                        <CheckBox IsChecked="{Binding Checked}">
+                        <CheckBox IsChecked="{Binding IsChecked}">
                             <Label>
                                 <TextBlock Text="{Binding Title}" TextWrapping="Wrap" />
                             </Label>

app/Desktop/Dialogs/CheckBox/CheckBoxDialogModel.cs

@@ -2,11 +2,11 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
-using DHT.Utils.Models;
+using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace DHT.Desktop.Dialogs.CheckBox;
 
-class CheckBoxDialogModel : BaseModel {
+class CheckBoxDialogModel : ObservableObject {
 	public string Title { get; init; } = "";
 
 	private IReadOnlyList<CheckBoxItem> items = Array.Empty<CheckBoxItem>();
@@ -29,8 +29,8 @@ class CheckBoxDialogModel : BaseModel {
 
 	private bool pauseCheckEvents = false;
 
-	public bool AreAllSelected => Items.All(static item => item.Checked);
+	public bool AreAllSelected => Items.All(static item => item.IsChecked);
-	public bool AreNoneSelected => Items.All(static item => !item.Checked);
+	public bool AreNoneSelected => Items.All(static item => !item.IsChecked);
 
 	public void SelectAll() => SetAllChecked(true);
 	public void SelectNone() => SetAllChecked(false);
@@ -39,7 +39,7 @@ class CheckBoxDialogModel : BaseModel {
 		pauseCheckEvents = true;
 
 		foreach (var item in Items) {
-			item.Checked = isChecked;
+			item.IsChecked = isChecked;
 		}
 
 		pauseCheckEvents = false;
@@ -52,16 +52,16 @@ class CheckBoxDialogModel : BaseModel {
 	}
 
 	private void OnItemPropertyChanged(object? sender, PropertyChangedEventArgs e) {
-		if (!pauseCheckEvents && e.PropertyName == nameof(CheckBoxItem.Checked)) {
+		if (!pauseCheckEvents && e.PropertyName == nameof(CheckBoxItem.IsChecked)) {
 			UpdateBulkButtons();
 		}
 	}
 }
 
 sealed class CheckBoxDialogModel<T> : CheckBoxDialogModel {
-	public new IReadOnlyList<CheckBoxItem<T>> Items { get; }
+	private new IReadOnlyList<CheckBoxItem<T>> Items { get; }
 
-	public IEnumerable<CheckBoxItem<T>> SelectedItems => Items.Where(static item => item.Checked);
+	public IEnumerable<CheckBoxItem<T>> SelectedItems => Items.Where(static item => item.IsChecked);
 
 	public CheckBoxDialogModel(IEnumerable<CheckBoxItem<T>> items) {
 		this.Items = new List<CheckBoxItem<T>>(items);

app/Desktop/Dialogs/CheckBox/CheckBoxItem.cs

@@ -1,17 +1,13 @@
-using DHT.Utils.Models;
+using CommunityToolkit.Mvvm.ComponentModel;
 
 namespace DHT.Desktop.Dialogs.CheckBox;
 
-class CheckBoxItem : BaseModel {
+partial class CheckBoxItem : ObservableObject {
 	public string Title { get; init; } = "";
 	public object? Item { get; init; } = null;
 
+	[ObservableProperty]
 	private bool isChecked = false;
-
-	public bool Checked {
-		get => isChecked;
-		set => Change(ref isChecked, value);
-	}
 }
 
 sealed class CheckBoxItem<T> : CheckBoxItem {

app/Desktop/Dialogs/Message/MessageDialog.axaml

@@ -5,6 +5,7 @@
         xmlns:namespace="clr-namespace:DHT.Desktop.Dialogs.Message"
         mc:Ignorable="d" d:DesignWidth="500"
         x:Class="DHT.Desktop.Dialogs.Message.MessageDialog"
+        x:DataType="namespace:MessageDialogModel"
         Title="{Binding Title}"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
         Width="500" SizeToContent="Height" CanResize="False"

app/Desktop/Dialogs/Progress/IProgressCallback.cs

@@ -4,4 +4,6 @@ namespace DHT.Desktop.Dialogs.Progress;
 
 interface IProgressCallback {
 	Task Update(string message, int finishedItems, int totalItems);
+	Task UpdateIndeterminate(string message);
+	Task Hide();
 }

app/Desktop/Dialogs/Progress/ProgressDialog.axaml

@@ -5,6 +5,7 @@
         xmlns:namespace="clr-namespace:DHT.Desktop.Dialogs.Progress"
         mc:Ignorable="d" d:DesignWidth="500"
         x:Class="DHT.Desktop.Dialogs.Progress.ProgressDialog"
+        x:DataType="namespace:ProgressDialogModel"
         Title="{Binding Title}"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
         Opened="OnOpened"
@@ -31,12 +32,18 @@
         </Style>
     </Window.Styles>
 
-    <StackPanel Margin="20">
+    <ItemsRepeater ItemsSource="{Binding Items}" Margin="0 10">
-        <DockPanel>
+        <ItemsRepeater.ItemTemplate>
-            <TextBlock DockPanel.Dock="Right" Text="{Binding Items}" Classes="items" />
+            <DataTemplate>
-            <TextBlock DockPanel.Dock="Left" Text="{Binding Message}" />
+                <StackPanel Margin="20 10" IsHitTestVisible="{Binding IsVisible}" Opacity="{Binding Opacity}">
-        </DockPanel>
+                    <DockPanel>
-        <ProgressBar Value="{Binding Progress}" />
+                        <TextBlock DockPanel.Dock="Right" Text="{Binding Items}" Classes="items" />
-    </StackPanel>
+                        <TextBlock DockPanel.Dock="Left" Text="{Binding Message}" />
+                    </DockPanel>
+                    <ProgressBar IsIndeterminate="{Binding IsIndeterminate}" Value="{Binding Progress}" />
+                </StackPanel>
+            </DataTemplate>
+        </ItemsRepeater.ItemTemplate>
+    </ItemsRepeater>
 
 </Window>

app/Desktop/Dialogs/Progress/ProgressDialog.axaml.cs

@@ -7,7 +7,60 @@ namespace DHT.Desktop.Dialogs.Progress;
 
 [SuppressMessage("ReSharper", "MemberCanBeInternal")]
 public sealed partial class ProgressDialog : Window {
+	internal static async Task Show(Window owner, string title, Func<ProgressDialog, IProgressCallback, Task> action) {
+		var taskCompletionSource = new TaskCompletionSource();
+		var dialog = new ProgressDialog();
+		
+		dialog.DataContext = new ProgressDialogModel(title, async callbacks => {
+			try {
+				await action(dialog, callbacks[0]);
+				taskCompletionSource.SetResult();
+			} catch (Exception e) {
+				taskCompletionSource.SetException(e);
+			}
+		});
+		
+		await dialog.ShowProgressDialog(owner);
+		await taskCompletionSource.Task;
+	}
+	
+	internal static async Task ShowIndeterminate(Window owner, string title, string message, Func<ProgressDialog, Task> action) {
+		var taskCompletionSource = new TaskCompletionSource();
+		var dialog = new ProgressDialog();
+		
+		dialog.DataContext = new ProgressDialogModel(title, async callbacks => {
+			await callbacks[0].UpdateIndeterminate(message);
+			try {
+				await action(dialog);
+				taskCompletionSource.SetResult();
+			} catch (Exception e) {
+				taskCompletionSource.SetException(e);
+			}
+		});
+		
+		await dialog.ShowProgressDialog(owner);
+		await taskCompletionSource.Task;
+	}
+	
+	internal static async Task<T> ShowIndeterminate<T>(Window owner, string title, string message, Func<ProgressDialog, Task<T>> action) {
+		var taskCompletionSource = new TaskCompletionSource<T>();
+		var dialog = new ProgressDialog();
+
+		dialog.DataContext = new ProgressDialogModel(title, async callbacks => {
+			await callbacks[0].UpdateIndeterminate(message);
+			try {
+				taskCompletionSource.SetResult(await action(dialog));
+			} catch (Exception e) {
+				taskCompletionSource.SetException(e);
+			}
+		});
+		
+		await dialog.ShowProgressDialog(owner);
+		return await taskCompletionSource.Task;
+	}
+
 	private bool isFinished = false;
+	private Task progressTask = Task.CompletedTask;
 
 	public ProgressDialog() {
 		InitializeComponent();
@@ -15,7 +68,8 @@ public sealed partial class ProgressDialog : Window {
 
 	public void OnOpened(object? sender, EventArgs e) {
 		if (DataContext is ProgressDialogModel model) {
-			Task.Run(model.StartTask).ContinueWith(OnFinished, TaskScheduler.FromCurrentSynchronizationContext());
+			progressTask = Task.Run(model.StartTask);
+			progressTask.ContinueWith(OnFinished, TaskScheduler.FromCurrentSynchronizationContext());
 		}
 	}
 
@@ -27,4 +81,9 @@ public sealed partial class ProgressDialog : Window {
 		isFinished = true;
 		Close();
 	}
+
+	public async Task ShowProgressDialog(Window owner) {
+		await ShowDialog(owner);
+		await progressTask;
+	}
 }

app/Desktop/Dialogs/Progress/ProgressDialogModel.cs

@@ -1,65 +1,63 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 using Avalonia.Threading;
 using DHT.Desktop.Common;
-using DHT.Utils.Models;
 
 namespace DHT.Desktop.Dialogs.Progress;
 
-sealed class ProgressDialogModel : BaseModel {
+sealed class ProgressDialogModel {
 	public string Title { get; init; } = "";
 
-	private string message = "";
+	public IReadOnlyList<ProgressItem> Items { get; } = Array.Empty<ProgressItem>();
-
-	public string Message {
-		get => message;
-		private set => Change(ref message, value);
-	}
-
-	private string items = "";
-
-	public string Items {
-		get => items;
-		private set => Change(ref items, value);
-	}
-
-	private int progress = 0;
-
-	public int Progress {
-		get => progress;
-		private set => Change(ref progress, value);
-	}
 
 	private readonly TaskRunner? task;
 
 	[Obsolete("Designer")]
 	public ProgressDialogModel() {}
 
-	public ProgressDialogModel(TaskRunner task) {
+	public ProgressDialogModel(string title, TaskRunner task, int progressItems = 1) {
+		this.Title = title;
 		this.task = task;
+		this.Items = Enumerable.Range(0, progressItems).Select(static _ => new ProgressItem()).ToArray();
 	}
 
 	internal async Task StartTask() {
 		if (task != null) {
-			await task(new Callback(this));
+			await task(Items.Select(static item => new Callback(item)).ToArray());
 		}
 	}
 
-	public delegate Task TaskRunner(IProgressCallback callback);
+	public delegate Task TaskRunner(IReadOnlyList<IProgressCallback> callbacks);
 
 	private sealed class Callback : IProgressCallback {
-		private readonly ProgressDialogModel model;
+		private readonly ProgressItem item;
 
-		public Callback(ProgressDialogModel model) {
+		public Callback(ProgressItem item) {
-			this.model = model;
+			this.item = item;
 		}
 
-		async Task IProgressCallback.Update(string message, int finishedItems, int totalItems) {
+		public async Task Update(string message, int finishedItems, int totalItems) {
 			await Dispatcher.UIThread.InvokeAsync(() => {
-				model.Message = message;
+				item.Message = message;
-				model.Items = finishedItems.Format() + " / " + totalItems.Format();
+				item.Items = totalItems == 0 ? string.Empty : finishedItems.Format() + " / " + totalItems.Format();
-				model.Progress = 100 * finishedItems / totalItems;
+				item.Progress = totalItems == 0 ? 0 : 100 * finishedItems / totalItems;
+				item.IsIndeterminate = false;
 			});
 		}
+
+		public async Task UpdateIndeterminate(string message) {
+			await Dispatcher.UIThread.InvokeAsync(() => {
+				item.Message = message;
+				item.Items = string.Empty;
+				item.Progress = 0;
+				item.IsIndeterminate = true;
+			});
+		}
+
+		public Task Hide() {
+			return Update(string.Empty, 0, 0);
+		}
 	}
 }

app/Desktop/Dialogs/Progress/ProgressItem.cs

@@ -0,0 +1,30 @@
+using CommunityToolkit.Mvvm.ComponentModel;
+
+namespace DHT.Desktop.Dialogs.Progress;
+
+sealed partial class ProgressItem : ObservableObject {
+	[ObservableProperty(Setter = Access.Private)]
+	[NotifyPropertyChangedFor(nameof(Opacity))]
+	private bool isVisible = false;
+
+	public double Opacity => IsVisible ? 1.0 : 0.0;
+
+	private string message = "";
+
+	public string Message {
+		get => message;
+		set {
+			SetProperty(ref message, value);
+			IsVisible = !string.IsNullOrEmpty(value);
+		}
+	}
+
+	[ObservableProperty]
+	private string items = "";
+
+	[ObservableProperty]
+	private int progress = 0;
+
+	[ObservableProperty]
+	private bool isIndeterminate;
+}

app/Desktop/Dialogs/TextBox/TextBoxDialog.axaml

@@ -5,6 +5,7 @@
         xmlns:namespace="clr-namespace:DHT.Desktop.Dialogs.TextBox"
         mc:Ignorable="d" d:DesignWidth="500"
         x:Class="DHT.Desktop.Dialogs.TextBox.TextBoxDialog"
+        x:DataType="namespace:TextBoxDialogModel"
         Title="{Binding Title}"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
         Width="500" SizeToContent="Height" CanResize="False"

app/Desktop/Dialogs/TextBox/TextBoxDialog.axaml.cs

@@ -3,7 +3,7 @@ using Avalonia.Controls;
 using Avalonia.Interactivity;
 using DHT.Desktop.Dialogs.Message;
 
-namespace DHT.Desktop.Dialogs.TextBox; 
+namespace DHT.Desktop.Dialogs.TextBox;
 
 [SuppressMessage("ReSharper", "MemberCanBeInternal")]
 public sealed partial class TextBoxDialog : Window {

app/Desktop/Dialogs/TextBox/TextBoxDialogModel.cs

@@ -2,11 +2,11 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
-using DHT.Utils.Models;
+using CommunityToolkit.Mvvm.ComponentModel;
 
-namespace DHT.Desktop.Dialogs.TextBox; 
+namespace DHT.Desktop.Dialogs.TextBox;
 
-class TextBoxDialogModel : BaseModel {
+class TextBoxDialogModel : ObservableObject {
 	public string Title { get; init; } = "";
 	public string Description { get; init; } = "";
 
@@ -36,7 +36,7 @@ class TextBoxDialogModel : BaseModel {
 }
 
 sealed class TextBoxDialogModel<T> : TextBoxDialogModel {
-	public new IReadOnlyList<TextBoxItem<T>> Items { get; }
+	private new IReadOnlyList<TextBoxItem<T>> Items { get; }
 
 	public IEnumerable<TextBoxItem<T>> ValidItems => Items.Where(static item => item.IsValid);
 

app/Desktop/Dialogs/TextBox/TextBoxItem.cs

@@ -1,11 +1,11 @@
 using System;
 using System.Collections;
 using System.ComponentModel;
-using DHT.Utils.Models;
+using CommunityToolkit.Mvvm.ComponentModel;
 
-namespace DHT.Desktop.Dialogs.TextBox; 
+namespace DHT.Desktop.Dialogs.TextBox;
 
-class TextBoxItem : BaseModel, INotifyDataErrorInfo {
+class TextBoxItem : ObservableObject, INotifyDataErrorInfo {
 	public string Title { get; init; } = "";
 	public object? Item { get; init; } = null;
 		
@@ -17,7 +17,7 @@ class TextBoxItem : BaseModel, INotifyDataErrorInfo {
 	public string Value {
 		get => this.value;
 		set {
-			Change(ref this.value, value);
+			SetProperty(ref this.value, value);
 			ErrorsChanged?.Invoke(this, new DataErrorsChangedEventArgs(nameof(Value)));
 		}
 	}

app/Desktop/Discord/DiscordAppSettings.cs

@@ -1,9 +1,9 @@
 using System;
-using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Text.Json;
+using System.Text.Json.Nodes;
 using System.Threading.Tasks;
 using DHT.Utils.Logging;
 using static System.Environment.SpecialFolder;
@@ -39,7 +39,8 @@ static class DiscordAppSettings {
 
 	public static async Task<bool?> AreDevToolsEnabled() {
 		try {
-			return AreDevToolsEnabled(await ReadSettingsJson());
+			var settingsJson = await ReadSettingsJson();
+			return AreDevToolsEnabled(settingsJson);
 		} catch (Exception e) {
 			Log.Error("Cannot read settings file.");
 			Log.Error(e);
@@ -47,12 +48,12 @@ static class DiscordAppSettings {
 		}
 	}
 
-	private static bool AreDevToolsEnabled(Dictionary<string, object?> json) {
+	private static bool AreDevToolsEnabled(JsonObject json) {
-		return json.TryGetValue(JsonKeyDevTools, out var value) && value is JsonElement { ValueKind: JsonValueKind.True };
+		return json.TryGetPropertyValue(JsonKeyDevTools, out var node) && node?.GetValueKind() == JsonValueKind.True;
 	}
 
 	public static async Task<SettingsJsonResult> ConfigureDevTools(bool enable) {
-		Dictionary<string, object?> json;
+		JsonObject json;
 
 		try {
 			json = await ReadSettingsJson();
@@ -109,13 +110,13 @@ static class DiscordAppSettings {
 		return SettingsJsonResult.Success;
 	}
 
-	private static async Task<Dictionary<string, object?>> ReadSettingsJson() {
+	private static async Task<JsonObject> ReadSettingsJson() {
 		await using var stream = new FileStream(JsonFilePath, FileMode.Open, FileAccess.Read, FileShare.Read);
-		return await JsonSerializer.DeserializeAsync<Dictionary<string, object?>?>(stream) ?? throw new JsonException();
+		return await JsonSerializer.DeserializeAsync(stream, DiscordAppSettingsJsonContext.Default.JsonObject) ?? throw new JsonException();
 	}
 
-	private static async Task WriteSettingsJson(Dictionary<string, object?> json) {
+	private static async Task WriteSettingsJson(JsonObject json) {
 		await using var stream = new FileStream(JsonFilePath, FileMode.Truncate, FileAccess.Write, FileShare.None);
-		await JsonSerializer.SerializeAsync(stream, json, new JsonSerializerOptions { WriteIndented = true });
+		await JsonSerializer.SerializeAsync(stream, json, DiscordAppSettingsJsonContext.Default.JsonObject);
 	}
 }

app/Desktop/Discord/DiscordAppSettingsJsonContext.cs

@@ -0,0 +1,8 @@
+using System.Text.Json.Nodes;
+using System.Text.Json.Serialization;
+
+namespace DHT.Desktop.Discord;
+
+[JsonSourceGenerationOptions(GenerationMode = JsonSourceGenerationMode.Default, WriteIndented = true)]
+[JsonSerializable(typeof(JsonObject))]
+sealed partial class DiscordAppSettingsJsonContext : JsonSerializerContext;

app/Desktop/Main/AboutWindow.axaml

@@ -5,6 +5,7 @@
         xmlns:main="clr-namespace:DHT.Desktop.Main"
         mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="295"
         x:Class="DHT.Desktop.Main.AboutWindow"
+        x:DataType="main:AboutWindowModel"
         Title="About Discord History Tracker"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
         Width="480" Height="295" CanResize="False"

app/Desktop/Main/Controls/AttachmentFilterPanelModel.cs

@@ -1,129 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using DHT.Desktop.Common;
-using DHT.Server.Data.Filters;
-using DHT.Server.Database;
-using DHT.Utils.Models;
-using DHT.Utils.Tasks;
-
-namespace DHT.Desktop.Main.Controls;
-
-sealed class AttachmentFilterPanelModel : BaseModel, IDisposable {
-	public sealed record Unit(string Name, uint Scale);
-
-	private static readonly Unit[] AllUnits = {
-		new ("B", 1),
-		new ("kB", 1024),
-		new ("MB", 1024 * 1024)
-	};
-
-	private static readonly HashSet<string> FilterProperties = new () {
-		nameof(LimitSize),
-		nameof(MaximumSize),
-		nameof(MaximumSizeUnit)
-	};
-
-	public string FilterStatisticsText { get; private set; } = "";
-
-	private bool limitSize = false;
-	private ulong maximumSize = 0L;
-	private Unit maximumSizeUnit = AllUnits[0];
-
-	public bool LimitSize {
-		get => limitSize;
-		set => Change(ref limitSize, value);
-	}
-
-	public ulong MaximumSize {
-		get => maximumSize;
-		set => Change(ref maximumSize, value);
-	}
-
-	public Unit MaximumSizeUnit {
-		get => maximumSizeUnit;
-		set => Change(ref maximumSizeUnit, value);
-	}
-
-	public IEnumerable<Unit> Units => AllUnits;
-
-	private readonly IDatabaseFile db;
-	private readonly string verb;
-
-	private readonly AsyncValueComputer<long> matchingAttachmentCountComputer;
-	private long? matchingAttachmentCount;
-	private long? totalAttachmentCount;
-
-	[Obsolete("Designer")]
-	public AttachmentFilterPanelModel() : this(DummyDatabaseFile.Instance) {}
-
-	public AttachmentFilterPanelModel(IDatabaseFile db, string verb = "Matches") {
-		this.db = db;
-		this.verb = verb;
-
-		this.matchingAttachmentCountComputer = AsyncValueComputer<long>.WithResultProcessor(SetAttachmentCounts).Build();
-
-		UpdateFilterStatistics();
-
-		PropertyChanged += OnPropertyChanged;
-		db.Statistics.PropertyChanged += OnDbStatisticsChanged;
-	}
-
-	public void Dispose() {
-		db.Statistics.PropertyChanged -= OnDbStatisticsChanged;
-	}
-
-	private void OnPropertyChanged(object? sender, PropertyChangedEventArgs e) {
-		if (e.PropertyName != null && FilterProperties.Contains(e.PropertyName)) {
-			UpdateFilterStatistics();
-		}
-	}
-
-	private void OnDbStatisticsChanged(object? sender, PropertyChangedEventArgs e) {
-		if (e.PropertyName == nameof(DatabaseStatistics.TotalAttachments)) {
-			totalAttachmentCount = db.Statistics.TotalAttachments;
-			UpdateFilterStatistics();
-		}
-	}
-
-	private void UpdateFilterStatistics() {
-		var filter = CreateFilter();
-		if (filter.IsEmpty) {
-			matchingAttachmentCountComputer.Cancel();
-			matchingAttachmentCount = totalAttachmentCount;
-			UpdateFilterStatisticsText();
-		}
-		else {
-			matchingAttachmentCount = null;
-			UpdateFilterStatisticsText();
-			matchingAttachmentCountComputer.Compute(() => db.CountAttachments(filter));
-		}
-	}
-
-	private void SetAttachmentCounts(long matchingAttachmentCount) {
-		this.matchingAttachmentCount = matchingAttachmentCount;
-		UpdateFilterStatisticsText();
-	}
-
-	private void UpdateFilterStatisticsText() {
-		var matchingAttachmentCountStr = matchingAttachmentCount?.Format() ?? "(...)";
-		var totalAttachmentCountStr = totalAttachmentCount?.Format() ?? "(...)";
-
-		FilterStatisticsText = verb + " " + matchingAttachmentCountStr + " out of " + totalAttachmentCountStr + " attachment" + (totalAttachmentCount is null or 1 ? "." : "s.");
-		OnPropertyChanged(nameof(FilterStatisticsText));
-	}
-
-	public AttachmentFilter CreateFilter() {
-		AttachmentFilter filter = new();
-
-		if (LimitSize) {
-			try {
-				filter.MaxBytes = maximumSize * maximumSizeUnit.Scale;
-			} catch (ArithmeticException) {
-				// set no size limit, because the overflown size is larger than any file could possibly be
-			}
-		}
-
-		return filter;
-	}
-}

app/Desktop/Main/Controls/DownloadItemFilterPanel.axaml

@@ -4,10 +4,11 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              mc:Ignorable="d"
-             x:Class="DHT.Desktop.Main.Controls.AttachmentFilterPanel">
+             x:Class="DHT.Desktop.Main.Controls.DownloadItemFilterPanel"
+             x:DataType="controls:DownloadItemFilterPanelModel">
 
     <Design.DataContext>
-        <controls:AttachmentFilterPanelModel />
+        <controls:DownloadItemFilterPanelModel />
     </Design.DataContext>
 
     <UserControl.Styles>

app/Desktop/Main/Controls/DownloadItemFilterPanel.axaml.cs

@@ -4,8 +4,8 @@ using Avalonia.Controls;
 namespace DHT.Desktop.Main.Controls;
 
 [SuppressMessage("ReSharper", "MemberCanBeInternal")]
-public sealed partial class AttachmentFilterPanel : UserControl {
+public sealed partial class DownloadItemFilterPanel : UserControl {
-	public AttachmentFilterPanel() {
+	public DownloadItemFilterPanel() {
 		InitializeComponent();
 	}
 }

app/Desktop/Main/Controls/DownloadItemFilterPanelModel.cs

@@ -0,0 +1,124 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Reactive.Linq;
+using System.Threading.Tasks;
+using Avalonia.ReactiveUI;
+using CommunityToolkit.Mvvm.ComponentModel;
+using DHT.Desktop.Common;
+using DHT.Server;
+using DHT.Server.Data.Filters;
+using DHT.Utils.Tasks;
+
+namespace DHT.Desktop.Main.Controls;
+
+sealed partial class DownloadItemFilterPanelModel : ObservableObject, IDisposable {
+	public sealed record Unit(string Name, uint Scale);
+
+	private static readonly Unit[] AllUnits = [
+		new Unit("B", 1),
+		new Unit("kB", 1024),
+		new Unit("MB", 1024 * 1024)
+	];
+
+	private static readonly HashSet<string> FilterProperties = [
+		nameof(LimitSize),
+		nameof(MaximumSize),
+		nameof(MaximumSizeUnit)
+	];
+
+	public string FilterStatisticsText { get; private set; } = "";
+
+	[ObservableProperty]
+	private bool limitSize = false;
+	
+	[ObservableProperty]
+	private ulong maximumSize = 0L;
+	
+	[ObservableProperty]
+	private Unit maximumSizeUnit = AllUnits[0];
+
+	public IEnumerable<Unit> Units => AllUnits;
+
+	private readonly State state;
+	private readonly string verb;
+
+	private readonly RestartableTask<long> downloadItemCountTask;
+	private long? matchingItemCount;
+	
+	private readonly IDisposable downloadItemCountSubscription;
+	private long? totalItemCount;
+
+	[Obsolete("Designer")]
+	public DownloadItemFilterPanelModel() : this(State.Dummy) {}
+
+	public DownloadItemFilterPanelModel(State state, string verb = "Matches") {
+		this.state = state;
+		this.verb = verb;
+
+		this.downloadItemCountTask = new RestartableTask<long>(SetMatchingCount, TaskScheduler.FromCurrentSynchronizationContext());
+		this.downloadItemCountSubscription = state.Db.Downloads.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnDownloadItemCountChanged);
+
+		UpdateFilterStatistics();
+
+		PropertyChanged += OnPropertyChanged;
+	}
+
+	public void Dispose() {
+		downloadItemCountTask.Cancel();
+		downloadItemCountSubscription.Dispose();
+	}
+
+	private void OnPropertyChanged(object? sender, PropertyChangedEventArgs e) {
+		if (e.PropertyName != null && FilterProperties.Contains(e.PropertyName)) {
+			UpdateFilterStatistics();
+		}
+	}
+	
+	private void OnDownloadItemCountChanged(long newItemCount) {
+		totalItemCount = newItemCount;
+		UpdateFilterStatistics();
+	}
+	
+
+	private void UpdateFilterStatistics() {
+		var filter = CreateFilter();
+		if (filter.IsEmpty) {
+			downloadItemCountTask.Cancel();
+			matchingItemCount = totalItemCount;
+			UpdateFilterStatisticsText();
+		}
+		else {
+			matchingItemCount = null;
+			UpdateFilterStatisticsText();
+			downloadItemCountTask.Restart(cancellationToken => state.Db.Downloads.Count(filter, cancellationToken));
+		}
+	}
+
+	private void SetMatchingCount(long matchingAttachmentCount) {
+		this.matchingItemCount = matchingAttachmentCount;
+		UpdateFilterStatisticsText();
+	}
+
+	private void UpdateFilterStatisticsText() {
+		var matchingItemCountStr = matchingItemCount?.Format() ?? "(...)";
+		var totalItemCountStr = totalItemCount?.Format() ?? "(...)";
+
+		FilterStatisticsText = verb + " " + matchingItemCountStr + " out of " + totalItemCountStr + " file" + (totalItemCount is null or 1 ? "." : "s.");
+		OnPropertyChanged(nameof(FilterStatisticsText));
+	}
+
+	public DownloadItemFilter CreateFilter() {
+		DownloadItemFilter filter = new ();
+
+		if (LimitSize) {
+			try {
+				filter.MaxBytes = maximumSize * maximumSizeUnit.Scale;
+			} catch (ArithmeticException) {
+				// set no size limit, because the overflown size is larger than any file could possibly be
+			}
+		}
+
+		return filter;
+	}
+}

app/Desktop/Main/Controls/MessageFilterPanel.axaml

@@ -4,7 +4,8 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              mc:Ignorable="d"
-             x:Class="DHT.Desktop.Main.Controls.MessageFilterPanel">
+             x:Class="DHT.Desktop.Main.Controls.MessageFilterPanel"
+             x:DataType="controls:MessageFilterPanelModel">
 
     <Design.DataContext>
         <controls:MessageFilterPanelModel />

app/Desktop/Main/Controls/MessageFilterPanelModel.cs

@@ -2,22 +2,25 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
+using System.Reactive.Linq;
 using System.Text;
 using System.Threading.Tasks;
 using Avalonia.Controls;
+using Avalonia.ReactiveUI;
+using CommunityToolkit.Mvvm.ComponentModel;
 using DHT.Desktop.Common;
 using DHT.Desktop.Dialogs.CheckBox;
 using DHT.Desktop.Dialogs.Message;
+using DHT.Desktop.Dialogs.Progress;
+using DHT.Server;
 using DHT.Server.Data;
 using DHT.Server.Data.Filters;
-using DHT.Server.Database;
-using DHT.Utils.Models;
 using DHT.Utils.Tasks;
 
 namespace DHT.Desktop.Main.Controls;
 
-sealed class MessageFilterPanelModel : BaseModel, IDisposable {
+sealed partial class MessageFilterPanelModel : ObservableObject, IDisposable {
-	private static readonly HashSet<string> FilterProperties = new () {
+	private static readonly HashSet<string> FilterProperties = [
 		nameof(FilterByDate),
 		nameof(StartDate),
 		nameof(EndDate),
@@ -25,7 +28,7 @@ sealed class MessageFilterPanelModel : BaseModel, IDisposable {
 		nameof(IncludedChannels),
 		nameof(FilterByUser),
 		nameof(IncludedUsers)
-	};
+	];
 
 	public string FilterStatisticsText { get; private set; } = "";
 
@@ -33,91 +36,76 @@ sealed class MessageFilterPanelModel : BaseModel, IDisposable {
 
 	public bool HasAnyFilters => FilterByDate || FilterByChannel || FilterByUser;
 
+	[ObservableProperty]
 	private bool filterByDate = false;
+
+	[ObservableProperty]
 	private DateTime? startDate = null;
+
+	[ObservableProperty]
 	private DateTime? endDate = null;
+
+	[ObservableProperty]
 	private bool filterByChannel = false;
+
+	[ObservableProperty]
 	private HashSet<ulong>? includedChannels = null;
+
+	[ObservableProperty]
 	private bool filterByUser = false;
+
+	[ObservableProperty]
 	private HashSet<ulong>? includedUsers = null;
 
-	public bool FilterByDate {
+	[ObservableProperty]
-		get => filterByDate;
-		set => Change(ref filterByDate, value);
-	}
-
-	public DateTime? StartDate {
-		get => startDate;
-		set => Change(ref startDate, value);
-	}
-
-	public DateTime? EndDate {
-		get => endDate;
-		set => Change(ref endDate, value);
-	}
-
-	public bool FilterByChannel {
-		get => filterByChannel;
-		set => Change(ref filterByChannel, value);
-	}
-
-	public HashSet<ulong> IncludedChannels {
-		get => includedChannels ?? db.GetAllChannels().Select(static channel => channel.Id).ToHashSet();
-		set => Change(ref includedChannels, value);
-	}
-
-	public bool FilterByUser {
-		get => filterByUser;
-		set => Change(ref filterByUser, value);
-	}
-
-	public HashSet<ulong> IncludedUsers {
-		get => includedUsers ?? db.GetAllUsers().Select(static user => user.Id).ToHashSet();
-		set => Change(ref includedUsers, value);
-	}
-
 	private string channelFilterLabel = "";
 
-	public string ChannelFilterLabel {
+	[ObservableProperty]
-		get => channelFilterLabel;
-		set => Change(ref channelFilterLabel, value);
-	}
-
 	private string userFilterLabel = "";
 
-	public string UserFilterLabel {
-		get => userFilterLabel;
-		set => Change(ref userFilterLabel, value);
-	}
-
 	private readonly Window window;
-	private readonly IDatabaseFile db;
+	private readonly State state;
 	private readonly string verb;
 
-	private readonly AsyncValueComputer<long> exportedMessageCountComputer;
+	private readonly RestartableTask<long> exportedMessageCountTask;
 	private long? exportedMessageCount;
+	
+	private readonly IDisposable messageCountSubscription;
 	private long? totalMessageCount;
+	
+	private readonly IDisposable channelCountSubscription;
+	private long? totalChannelCount;
+	
+	private readonly IDisposable userCountSubscription;
+	private long? totalUserCount;
 
 	[Obsolete("Designer")]
-	public MessageFilterPanelModel() : this(null!, DummyDatabaseFile.Instance) {}
+	public MessageFilterPanelModel() : this(null!, State.Dummy) {}
 
-	public MessageFilterPanelModel(Window window, IDatabaseFile db, string verb = "Matches") {
+	public MessageFilterPanelModel(Window window, State state, string verb = "Matches") {
 		this.window = window;
-		this.db = db;
+		this.state = state;
 		this.verb = verb;
 
-		this.exportedMessageCountComputer = AsyncValueComputer<long>.WithResultProcessor(SetExportedMessageCount).Build();
+		this.exportedMessageCountTask = new RestartableTask<long>(SetExportedMessageCount, TaskScheduler.FromCurrentSynchronizationContext());
+		
+		this.messageCountSubscription = state.Db.Messages.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnMessageCountChanged);
+		this.channelCountSubscription = state.Db.Channels.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnChannelCountChanged);
+		this.userCountSubscription = state.Db.Users.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnUserCountChanged);
 
 		UpdateFilterStatistics();
 		UpdateChannelFilterLabel();
 		UpdateUserFilterLabel();
-
+		
 		PropertyChanged += OnPropertyChanged;
-		db.Statistics.PropertyChanged += OnDbStatisticsChanged;
 	}
 
 	public void Dispose() {
-		db.Statistics.PropertyChanged -= OnDbStatisticsChanged;
+		exportedMessageCountTask.Cancel();
+		
+		messageCountSubscription.Dispose();
+		channelCountSubscription.Dispose();
+		userCountSubscription.Dispose();
 	}
 
 	private void OnPropertyChanged(object? sender, PropertyChangedEventArgs e) {
@@ -134,30 +122,54 @@ sealed class MessageFilterPanelModel : BaseModel, IDisposable {
 		}
 	}
 
-	private void OnDbStatisticsChanged(object? sender, PropertyChangedEventArgs e) {
+	private void OnMessageCountChanged(long newMessageCount) {
-		if (e.PropertyName == nameof(DatabaseStatistics.TotalMessages)) {
+		totalMessageCount = newMessageCount;
-			totalMessageCount = db.Statistics.TotalMessages;
+		UpdateFilterStatistics();
-			UpdateFilterStatistics();
+	}
+
+	private void OnChannelCountChanged(long newChannelCount) {
+		totalChannelCount = newChannelCount;
+		UpdateChannelFilterLabel();
+	}
+	
+	private void OnUserCountChanged(long newUserCount) {
+		totalUserCount = newUserCount;
+		UpdateUserFilterLabel();
+	}
+
+	private void UpdateChannelFilterLabel() {
+		if (totalChannelCount.HasValue) {
+			long total = totalChannelCount.Value;
+			long included = FilterByChannel && IncludedChannels != null ? IncludedChannels.Count : total;
+			ChannelFilterLabel = "Selected " + included.Format() + " / " + total.Pluralize("channel") + ".";
 		}
-		else if (e.PropertyName == nameof(DatabaseStatistics.TotalChannels)) {
+		else {
-			UpdateChannelFilterLabel();
+			ChannelFilterLabel = "Loading...";
 		}
-		else if (e.PropertyName == nameof(DatabaseStatistics.TotalUsers)) {
+	}
-			UpdateUserFilterLabel();
+
+	private void UpdateUserFilterLabel() {
+		if (totalUserCount.HasValue) {
+			long total = totalUserCount.Value;
+			long included = FilterByUser && IncludedUsers != null ? IncludedUsers.Count : total;
+			UserFilterLabel = "Selected " + included.Format() + " / " + total.Pluralize("user") + ".";
+		}
+		else {
+			UserFilterLabel = "Loading...";
 		}
 	}
 
 	private void UpdateFilterStatistics() {
 		var filter = CreateFilter();
 		if (filter.IsEmpty) {
-			exportedMessageCountComputer.Cancel();
+			exportedMessageCountTask.Cancel();
 			exportedMessageCount = totalMessageCount;
 			UpdateFilterStatisticsText();
 		}
 		else {
 			exportedMessageCount = null;
 			UpdateFilterStatisticsText();
-			exportedMessageCountComputer.Compute(() => db.CountMessages(filter));
+			exportedMessageCountTask.Restart(cancellationToken => state.Db.Messages.Count(filter, cancellationToken));
 		}
 	}
 
@@ -174,103 +186,98 @@ sealed class MessageFilterPanelModel : BaseModel, IDisposable {
 		OnPropertyChanged(nameof(FilterStatisticsText));
 	}
 
-	public async void OpenChannelFilterDialog() {
+	public async Task OpenChannelFilterDialog() {
-		var servers = db.GetAllServers().ToDictionary(static server => server.Id);
+		async Task<List<CheckBoxItem<ulong>>> PrepareChannelItems(ProgressDialog dialog) {
-		var items = new List<CheckBoxItem<ulong>>();
+			var items = new List<CheckBoxItem<ulong>>();
-		var included = IncludedChannels;
+			var servers = await state.Db.Servers.Get().ToDictionaryAsync(static server => server.Id);
 
-		foreach (var channel in db.GetAllChannels()) {
+			await foreach (var channel in state.Db.Channels.Get()) {
-			var channelId = channel.Id;
+				var channelId = channel.Id;
-			var channelName = channel.Name;
+				var channelName = channel.Name;
 
-			string title;
+				string title;
-			if (servers.TryGetValue(channel.Server, out var server)) {
+				if (servers.TryGetValue(channel.Server, out var server)) {
-				var titleBuilder = new StringBuilder();
+					var titleBuilder = new StringBuilder();
-				var serverType = server.Type;
+					var serverType = server.Type;
 
-				titleBuilder.Append('[')
+					titleBuilder.Append('[')
-				            .Append(ServerTypes.ToString(serverType))
+					            .Append(ServerTypes.ToString(serverType))
-				            .Append("] ");
+					            .Append("] ");
 
-				if (serverType == ServerType.DirectMessage) {
+					if (serverType == ServerType.DirectMessage) {
-					titleBuilder.Append(channelName);
+						titleBuilder.Append(channelName);
+					}
+					else {
+						titleBuilder.Append(server.Name)
+						            .Append(" - ")
+						            .Append(channelName);
+					}
+
+					title = titleBuilder.ToString();
 				}
 				else {
-					titleBuilder.Append(server.Name)
+					title = channelName;
-					            .Append(" - ")
-					            .Append(channelName);
 				}
 
-				title = titleBuilder.ToString();
+				items.Add(new CheckBoxItem<ulong>(channelId) {
-			}
+					Title = title,
-			else {
+					IsChecked = IncludedChannels == null || IncludedChannels.Contains(channelId)
-				title = channelName;
+				});
 			}
 
-			items.Add(new CheckBoxItem<ulong>(channelId) {
+			return items;
-				Title = title,
-				Checked = included.Contains(channelId)
-			});
 		}
 
-		var result = await OpenIdFilterDialog(window, "Included Channels", items);
+		const string Title = "Included Channels";
+
+		List<CheckBoxItem<ulong>> items;
+		try {
+			items = await ProgressDialog.ShowIndeterminate(window, Title, "Loading channels...", PrepareChannelItems);
+		} catch (Exception e) {
+			await Dialog.ShowOk(window, Title, "Error loading channels: " + e.Message);
+			return;
+		}
+
+		var result = await OpenIdFilterDialog(Title, items);
 		if (result != null) {
 			IncludedChannels = result;
 		}
 	}
 
-	public async void OpenUserFilterDialog() {
+	public async Task OpenUserFilterDialog() {
-		var items = new List<CheckBoxItem<ulong>>();
+		async Task<List<CheckBoxItem<ulong>>> PrepareUserItems(ProgressDialog dialog) {
-		var included = IncludedUsers;
+			var checkBoxItems = new List<CheckBoxItem<ulong>>();
 
-		foreach (var user in db.GetAllUsers()) {
+			await foreach (var user in state.Db.Users.Get()) {
-			var name = user.Name;
+				var name = user.Name;
-			var discriminator = user.Discriminator;
+				var discriminator = user.Discriminator;
 
-			items.Add(new CheckBoxItem<ulong>(user.Id) {
+				checkBoxItems.Add(new CheckBoxItem<ulong>(user.Id) {
-				Title = discriminator == null ? name : name + " #" + discriminator,
+					Title = discriminator == null ? name : name + " #" + discriminator,
-				Checked = included.Contains(user.Id)
+					IsChecked = IncludedUsers == null || IncludedUsers.Contains(user.Id)
-			});
+				});
+			}
+
+			return checkBoxItems;
 		}
 
-		var result = await OpenIdFilterDialog(window, "Included Users", items);
+		const string Title = "Included Users";
+
+		List<CheckBoxItem<ulong>> items;
+		try {
+			items = await ProgressDialog.ShowIndeterminate(window, Title, "Loading users...", PrepareUserItems);
+		} catch (Exception e) {
+			await Dialog.ShowOk(window, Title, "Error loading users: " + e.Message);
+			return;
+		}
+
+		var result = await OpenIdFilterDialog(Title, items);
 		if (result != null) {
 			IncludedUsers = result;
 		}
 	}
 
-	private void UpdateChannelFilterLabel() {
+	private async Task<HashSet<ulong>?> OpenIdFilterDialog(string title, List<CheckBoxItem<ulong>> items) {
-		long total = db.Statistics.TotalChannels;
-		long included = FilterByChannel ? IncludedChannels.Count : total;
-		ChannelFilterLabel = "Selected " + included.Format() + " / " + total.Pluralize("channel") + ".";
-	}
-
-	private void UpdateUserFilterLabel() {
-		long total = db.Statistics.TotalUsers;
-		long included = FilterByUser ? IncludedUsers.Count : total;
-		UserFilterLabel = "Selected " + included.Format() + " / " + total.Pluralize("user") + ".";
-	}
-
-	public MessageFilter CreateFilter() {
-		MessageFilter filter = new();
-
-		if (FilterByDate) {
-			filter.StartDate = StartDate;
-			filter.EndDate = EndDate?.AddDays(1).AddMilliseconds(-1);
-		}
-
-		if (FilterByChannel) {
-			filter.ChannelIds = new HashSet<ulong>(IncludedChannels);
-		}
-
-		if (FilterByUser) {
-			filter.UserIds = new HashSet<ulong>(IncludedUsers);
-		}
-
-		return filter;
-	}
-
-	private static async Task<HashSet<ulong>?> OpenIdFilterDialog(Window window, string title, List<CheckBoxItem<ulong>> items) {
 		items.Sort(static (item1, item2) => item1.Title.CompareTo(item2.Title));
 
 		var model = new CheckBoxDialogModel<ulong>(items) {
@@ -282,4 +289,23 @@ sealed class MessageFilterPanelModel : BaseModel, IDisposable {
 
 		return result == DialogResult.OkCancel.Ok ? model.SelectedItems.Select(static item => item.Item).ToHashSet() : null;
 	}
+
+	public MessageFilter CreateFilter() {
+		MessageFilter filter = new ();
+
+		if (FilterByDate) {
+			filter.StartDate = StartDate;
+			filter.EndDate = EndDate?.AddDays(1).AddMilliseconds(-1);
+		}
+
+		if (FilterByChannel && IncludedChannels != null) {
+			filter.ChannelIds = new HashSet<ulong>(IncludedChannels);
+		}
+
+		if (FilterByUser && IncludedUsers != null) {
+			filter.UserIds = new HashSet<ulong>(IncludedUsers);
+		}
+
+		return filter;
+	}
 }

app/Desktop/Main/Controls/ServerConfigurationPanel.axaml

@@ -4,7 +4,8 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              mc:Ignorable="d"
-             x:Class="DHT.Desktop.Main.Controls.ServerConfigurationPanel">
+             x:Class="DHT.Desktop.Main.Controls.ServerConfigurationPanel"
+             x:DataType="controls:ServerConfigurationPanelModel">
 
     <Design.DataContext>
         <controls:ServerConfigurationPanelModel />

app/Desktop/Main/Controls/ServerConfigurationPanelModel.cs

@@ -1,96 +1,95 @@
 using System;
+using System.Threading.Tasks;
 using Avalonia.Controls;
+using Avalonia.Threading;
+using CommunityToolkit.Mvvm.ComponentModel;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Server;
-using DHT.Server.Database;
+using DHT.Server;
 using DHT.Server.Service;
-using DHT.Utils.Models;
+using DHT.Utils.Logging;
 
 namespace DHT.Desktop.Main.Controls;
 
-sealed class ServerConfigurationPanelModel : BaseModel, IDisposable {
+sealed partial class ServerConfigurationPanelModel : ObservableObject, IDisposable {
+	private static readonly Log Log = Log.ForType<ServerConfigurationPanelModel>();
+	
+	[ObservableProperty]
+	[NotifyPropertyChangedFor(nameof(HasMadeChanges))]
 	private string inputPort;
 
-	public string InputPort {
+	[ObservableProperty]
-		get => inputPort;
+	[NotifyPropertyChangedFor(nameof(HasMadeChanges))]
-		set {
-			Change(ref inputPort, value);
-			OnPropertyChanged(nameof(HasMadeChanges));
-		}
-	}
-
 	private string inputToken;
 
-	public string InputToken {
+	public bool HasMadeChanges => ServerConfiguration.Port.ToString() != InputPort || ServerConfiguration.Token != InputToken;
-		get => inputToken;
-		set {
-			Change(ref inputToken, value);
-			OnPropertyChanged(nameof(HasMadeChanges));
-		}
-	}
-
-	public bool HasMadeChanges => ServerManager.Port.ToString() != InputPort || ServerManager.Token != InputToken;
 
+	[ObservableProperty(Setter = Access.Private)]
 	private bool isToggleServerButtonEnabled = true;
 
-	public bool IsToggleServerButtonEnabled {
+	public string ToggleServerButtonText => server.IsRunning ? "Stop Server" : "Start Server";
-		get => isToggleServerButtonEnabled;
-		set => Change(ref isToggleServerButtonEnabled, value);
-	}
-
-	public string ToggleServerButtonText => serverManager.IsRunning ? "Stop Server" : "Start Server";
-
-	public event EventHandler<StatusBarModel.Status>? ServerStatusChanged;
 
 	private readonly Window window;
-	private readonly ServerManager serverManager;
+	private readonly ServerManager server;
 
 	[Obsolete("Designer")]
-	public ServerConfigurationPanelModel() : this(null!, new ServerManager(DummyDatabaseFile.Instance)) {}
+	public ServerConfigurationPanelModel() : this(null!, State.Dummy) {}
 
-	public ServerConfigurationPanelModel(Window window, ServerManager serverManager) {
+	public ServerConfigurationPanelModel(Window window, State state) {
 		this.window = window;
-		this.serverManager = serverManager;
+		this.server = state.Server;
-		this.inputPort = ServerManager.Port.ToString();
+		this.inputPort = ServerConfiguration.Port.ToString();
-		this.inputToken = ServerManager.Token;
+		this.inputToken = ServerConfiguration.Token;
-	}
+		
-
+		server.StatusChanged += OnServerStatusChanged;
-	public void Initialize() {
-		ServerLauncher.ServerStatusChanged += ServerLauncherOnServerStatusChanged;
 	}
 
 	public void Dispose() {
-		ServerLauncher.ServerStatusChanged -= ServerLauncherOnServerStatusChanged;
+		server.StatusChanged -= OnServerStatusChanged;
 	}
 
-	private void ServerLauncherOnServerStatusChanged(object? sender, EventArgs e) {
+	private void OnServerStatusChanged(object? sender, ServerManager.Status e) {
-		ServerStatusChanged?.Invoke(this, serverManager.IsRunning ? StatusBarModel.Status.Ready : StatusBarModel.Status.Stopped);
+		Dispatcher.UIThread.InvokeAsync(UpdateServerStatus);
+	}
+
+	private void UpdateServerStatus() {
 		OnPropertyChanged(nameof(ToggleServerButtonText));
+	}
+
+	private async Task StartServer() {
+		IsToggleServerButtonEnabled = false;
+		
+		try {
+			await server.Start(ServerConfiguration.Port, ServerConfiguration.Token);
+		} catch (Exception e) {
+			Log.Error(e);
+			await Dialog.ShowOk(window, "Internal Server Error", e.Message);
+		}
+		
+		UpdateServerStatus();
 		IsToggleServerButtonEnabled = true;
 	}
 
-	private void BeforeServerStart() {
+	private async Task StopServer() {
 		IsToggleServerButtonEnabled = false;
-		ServerStatusChanged?.Invoke(this, StatusBarModel.Status.Starting);
+		
+		try {
+			await server.Stop();
+		} catch (Exception e) {
+			Log.Error(e);
+			await Dialog.ShowOk(window, "Internal Server Error", e.Message);
+		}
+		
+		UpdateServerStatus();
+		IsToggleServerButtonEnabled = true;
 	}
 
-	private void StartServer() {
+	public async Task OnClickToggleServerButton() {
-		BeforeServerStart();
+		if (server.IsRunning) {
-		serverManager.Launch();
+			await StopServer();
-	}
-
-	private void StopServer() {
-		IsToggleServerButtonEnabled = false;
-		ServerStatusChanged?.Invoke(this, StatusBarModel.Status.Stopping);
-		serverManager.Stop();
-	}
-
-	public void OnClickToggleServerButton() {
-		if (serverManager.IsRunning) {
-			StopServer();
 		}
 		else {
-			StartServer();
+			await StartServer();
 		}
 	}
 
@@ -98,19 +97,22 @@ sealed class ServerConfigurationPanelModel : BaseModel, IDisposable {
 		InputToken = ServerUtils.GenerateRandomToken(20);
 	}
 
-	public async void OnClickApplyChanges() {
+	public async Task OnClickApplyChanges() {
 		if (!ushort.TryParse(InputPort, out ushort port)) {
 			await Dialog.ShowOk(window, "Invalid Port", "Port must be a number between 0 and 65535.");
 			return;
 		}
 
-		BeforeServerStart();
+		ServerConfiguration.Port = port;
-		serverManager.Relaunch(port, InputToken);
+		ServerConfiguration.Token = inputToken;
+		
 		OnPropertyChanged(nameof(HasMadeChanges));
+		
+		await StartServer();
 	}
 
 	public void OnClickCancelChanges() {
-		InputPort = ServerManager.Port.ToString();
+		InputPort = ServerConfiguration.Port.ToString();
-		InputToken = ServerManager.Token;
+		InputToken = ServerConfiguration.Token;
 	}
 }

app/Desktop/Main/Controls/StatusBar.axaml

@@ -4,7 +4,8 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              mc:Ignorable="d"
-             x:Class="DHT.Desktop.Main.Controls.StatusBar">
+             x:Class="DHT.Desktop.Main.Controls.StatusBar"
+             x:DataType="controls:StatusBarModel">
 
     <Design.DataContext>
         <controls:StatusBarModel />
@@ -39,22 +40,22 @@
     <StackPanel Orientation="Horizontal" Margin="6 3">
         <StackPanel Orientation="Vertical" Width="65">
             <TextBlock Classes="label">Status</TextBlock>
-            <TextBlock FontSize="12" Margin="0 3 0 0" Text="{Binding StatusText}" />
+            <TextBlock FontSize="12" Margin="0 3 0 0" Text="{Binding ServerStatusText}" />
         </StackPanel>
         <Rectangle />
         <StackPanel Orientation="Vertical">
             <TextBlock Classes="label">Servers</TextBlock>
-            <TextBlock Classes="value" Text="{Binding DatabaseStatistics.TotalServers, Converter={StaticResource NumberValueConverter}}" />
+            <TextBlock Classes="value" Text="{Binding ServerCount, Mode=OneWay, Converter={StaticResource NumberValueConverter}}" />
         </StackPanel>
         <Rectangle />
         <StackPanel Orientation="Vertical">
             <TextBlock Classes="label">Channels</TextBlock>
-            <TextBlock Classes="value" Text="{Binding DatabaseStatistics.TotalChannels, Converter={StaticResource NumberValueConverter}}" />
+            <TextBlock Classes="value" Text="{Binding ChannelCount, Mode=OneWay, Converter={StaticResource NumberValueConverter}}" />
         </StackPanel>
         <Rectangle />
         <StackPanel Orientation="Vertical">
             <TextBlock Classes="label">Messages</TextBlock>
-            <TextBlock Classes="value" Text="{Binding DatabaseStatistics.TotalMessages, Converter={StaticResource NumberValueConverter}}" />
+            <TextBlock Classes="value" Text="{Binding MessageCount, Mode=OneWay, Converter={StaticResource NumberValueConverter}}" />
         </StackPanel>
     </StackPanel>
 

app/Desktop/Main/Controls/StatusBarModel.cs

@@ -1,45 +1,63 @@
 using System;
-using DHT.Server.Database;
+using System.Reactive.Linq;
-using DHT.Utils.Models;
+using Avalonia.ReactiveUI;
+using Avalonia.Threading;
+using CommunityToolkit.Mvvm.ComponentModel;
+using DHT.Server;
+using DHT.Server.Service;
 
 namespace DHT.Desktop.Main.Controls;
 
-sealed class StatusBarModel : BaseModel {
+sealed partial class StatusBarModel : ObservableObject, IDisposable {
-	public DatabaseStatistics DatabaseStatistics { get; }
+	[ObservableProperty(Setter = Access.Private)]
+	private long? serverCount;
+	
+	[ObservableProperty(Setter = Access.Private)]
+	private long? channelCount;
+	
+	[ObservableProperty(Setter = Access.Private)]
+	private long? messageCount;
 
-	private Status status = Status.Stopped;
+	[ObservableProperty(Setter = Access.Private)]
+	[NotifyPropertyChangedFor(nameof(ServerStatusText))]
+	private ServerManager.Status serverStatus;
 
-	public Status CurrentStatus {
+	public string ServerStatusText => serverStatus switch {
-		get => status;
+		ServerManager.Status.Starting => "STARTING",
-		set {
+		ServerManager.Status.Started  => "READY",
-			status = value;
+		ServerManager.Status.Stopping => "STOPPING",
-			OnPropertyChanged(nameof(StatusText));
+		ServerManager.Status.Stopped  => "STOPPED",
-		}
+		_                             => ""
-	}
+	};
 
-	public string StatusText {
+	private readonly State state;
-		get {
+	private readonly IDisposable serverCountSubscription;
-			return CurrentStatus switch {
+	private readonly IDisposable channelCountSubscription;
-				Status.Starting => "STARTING",
+	private readonly IDisposable messageCountSubscription;
-				Status.Ready    => "READY",
-				Status.Stopping => "STOPPING",
-				Status.Stopped  => "STOPPED",
-				_               => ""
-			};
-		}
-	}
 
 	[Obsolete("Designer")]
-	public StatusBarModel() : this(new DatabaseStatistics()) {}
+	public StatusBarModel() : this(State.Dummy) {}
 
-	public StatusBarModel(DatabaseStatistics databaseStatistics) {
+	public StatusBarModel(State state) {
-		this.DatabaseStatistics = databaseStatistics;
+		this.state = state;
+		
+		serverCountSubscription = state.Db.Servers.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(newServerCount => ServerCount = newServerCount);
+		channelCountSubscription = state.Db.Channels.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(newChannelCount => ChannelCount = newChannelCount);
+		messageCountSubscription = state.Db.Messages.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(newMessageCount => MessageCount = newMessageCount);
+
+		state.Server.StatusChanged += OnServerStatusChanged;
+		serverStatus = state.Server.IsRunning ? ServerManager.Status.Started : ServerManager.Status.Stopped;
 	}
 
-	public enum Status {
+	public void Dispose() {
-		Starting,
+		serverCountSubscription.Dispose();
-		Ready,
+		channelCountSubscription.Dispose();
-		Stopping,
+		messageCountSubscription.Dispose();
-		Stopped
+		
+		state.Server.StatusChanged -= OnServerStatusChanged;
+	}
+
+	private void OnServerStatusChanged(object? sender, ServerManager.Status e) {
+		Dispatcher.UIThread.InvokeAsync(() => ServerStatus = e);
 	}
 }

app/Desktop/Main/MainWindow.axaml

@@ -5,12 +5,13 @@
         xmlns:main="clr-namespace:DHT.Desktop.Main"
         mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
         x:Class="DHT.Desktop.Main.MainWindow"
+        x:DataType="main:MainWindowModel"
         Title="{Binding Title}"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
-        Width="800" Height="500"
+        Width="820" Height="520"
         MinWidth="520" MinHeight="300"
         WindowStartupLocation="CenterScreen"
-        Closed="OnClosed">
+        Closing="OnClosing">
 
     <Design.DataContext>
         <main:MainWindowModel />

app/Desktop/Main/MainWindow.axaml.cs

@@ -1,14 +1,18 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
 using System.IO;
+using System.Threading.Tasks;
 using Avalonia.Controls;
 using DHT.Desktop.Main.Pages;
+using DHT.Utils.Logging;
 using JetBrains.Annotations;
 
 namespace DHT.Desktop.Main;
 
 [SuppressMessage("ReSharper", "MemberCanBeInternal")]
 public sealed partial class MainWindow : Window {
+	private static readonly Log Log = Log.ForType<MainWindow>();
+	
 	[UsedImplicitly]
 	public MainWindow() {
 		InitializeComponent();
@@ -20,9 +24,24 @@ public sealed partial class MainWindow : Window {
 		DataContext = new MainWindowModel(this, args);
 	}
 
-	public void OnClosed(object? sender, EventArgs e) {
+	public async void OnClosing(object? sender, WindowClosingEventArgs e) {
-		if (DataContext is IDisposable disposable) {
+		e.Cancel = true;
-			disposable.Dispose();
+		Closing -= OnClosing;
+
+		try {
+			await Dispose();
+		} finally {
+			Close();
+		}
+	}
+
+	private async Task Dispose() {
+		if (DataContext is MainWindowModel model) {
+			try {
+				await model.DisposeAsync();
+			} catch (Exception ex) {
+				Log.Error("Caught exception while disposing window: " + ex);
+			}
 		}
 
 		foreach (var temporaryFile in ViewerPageModel.TemporaryFiles) {

app/Desktop/Main/MainWindowModel.cs

@@ -1,33 +1,38 @@
 using System;
-using System.ComponentModel;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Threading.Tasks;
 using Avalonia.Controls;
+using CommunityToolkit.Mvvm.ComponentModel;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Main.Screens;
 using DHT.Desktop.Server;
+using DHT.Server;
 using DHT.Server.Database;
-using DHT.Utils.Models;
+using DHT.Utils.Logging;
 
 namespace DHT.Desktop.Main;
 
-sealed class MainWindowModel : BaseModel, IDisposable {
+sealed partial class MainWindowModel : ObservableObject, IAsyncDisposable {
 	private const string DefaultTitle = "Discord History Tracker";
 
-	public string Title { get; private set; } = DefaultTitle;
+	private static readonly Log Log = Log.ForType<MainWindowModel>();
 
-	public UserControl CurrentScreen { get; private set; }
+	[ObservableProperty(Setter = Access.Private)]
+	private string title = DefaultTitle;
+
+	[ObservableProperty(Setter = Access.Private)]
+	private UserControl currentScreen;
 
 	private readonly WelcomeScreen welcomeScreen;
 	private readonly WelcomeScreenModel welcomeScreenModel;
 
-	private MainContentScreen? mainContentScreen;
 	private MainContentScreenModel? mainContentScreenModel;
 
 	private readonly Window window;
+	private readonly int? concurrentDownloads;
 
-	private IDatabaseFile? db;
+	private State? state;
 
 	[Obsolete("Designer")]
 	public MainWindowModel() : this(null!, Arguments.Empty) {}
@@ -36,10 +41,10 @@ sealed class MainWindowModel : BaseModel, IDisposable {
 		this.window = window;
 
 		welcomeScreenModel = new WelcomeScreenModel(window);
-		welcomeScreen = new WelcomeScreen { DataContext = welcomeScreenModel };
+		welcomeScreenModel.DatabaseSelected += OnDatabaseSelected;
-		CurrentScreen = welcomeScreen;
 
-		welcomeScreenModel.PropertyChanged += WelcomeScreenModelOnPropertyChanged;
+		welcomeScreen = new WelcomeScreen { DataContext = welcomeScreenModel };
+		currentScreen = welcomeScreen;
 
 		var dbFile = args.DatabaseFile;
 		if (!string.IsNullOrWhiteSpace(dbFile)) {
@@ -63,54 +68,63 @@ sealed class MainWindowModel : BaseModel, IDisposable {
 		}
 
 		if (args.ServerPort != null) {
-			ServerManager.Port = args.ServerPort.Value;
+			ServerConfiguration.Port = args.ServerPort.Value;
 		}
 
 		if (args.ServerToken != null) {
-			ServerManager.Token = args.ServerToken;
+			ServerConfiguration.Token = args.ServerToken;
+		}
+		
+		concurrentDownloads = args.ConcurrentDownloads;
+	}
+
+	private async void OnDatabaseSelected(object? sender, IDatabaseFile db) {
+		welcomeScreenModel.DatabaseSelected -= OnDatabaseSelected;
+		
+		await DisposeState();
+		
+		state = new State(db, concurrentDownloads);
+
+		try {
+			await state.Server.Start(ServerConfiguration.Port, ServerConfiguration.Token);
+		} catch (Exception ex) {
+			Log.Error(ex);
+			await Dialog.ShowOk(window, "Internal Server Error", ex.Message);
+		}
+
+		mainContentScreenModel = new MainContentScreenModel(window, state);
+		mainContentScreenModel.DatabaseClosed += MainContentScreenModelOnDatabaseClosed;
+		
+		Title = Path.GetFileName(state.Db.Path) + " - " + DefaultTitle;
+		CurrentScreen = new MainContentScreen { DataContext = mainContentScreenModel };
+
+		window.Focus();
+	}
+
+	private async void MainContentScreenModelOnDatabaseClosed(object? sender, EventArgs e) {
+		if (mainContentScreenModel != null) {
+			mainContentScreenModel.DatabaseClosed -= MainContentScreenModelOnDatabaseClosed;
+			mainContentScreenModel.Dispose();
+			mainContentScreenModel = null;
+		}
+
+		await DisposeState();
+
+		Title = DefaultTitle;
+		CurrentScreen = welcomeScreen;
+
+		welcomeScreenModel.DatabaseSelected += OnDatabaseSelected;
+	}
+
+	private async Task DisposeState() {
+		if (state != null) {
+			await state.DisposeAsync();
+			state = null;
 		}
 	}
 
-	private async void WelcomeScreenModelOnPropertyChanged(object? sender, PropertyChangedEventArgs e) {
+	public async ValueTask DisposeAsync() {
-		if (e.PropertyName == nameof(welcomeScreenModel.Db)) {
-			if (mainContentScreenModel != null) {
-				mainContentScreenModel.DatabaseClosed -= MainContentScreenModelOnDatabaseClosed;
-				mainContentScreenModel.Dispose();
-			}
-
-			db?.Dispose();
-			db = welcomeScreenModel.Db;
-
-			if (db == null) {
-				Title = DefaultTitle;
-				mainContentScreenModel = null;
-				mainContentScreen = null;
-				CurrentScreen = welcomeScreen;
-			}
-			else {
-				Title = Path.GetFileName(db.Path) + " - " + DefaultTitle;
-				mainContentScreenModel = new MainContentScreenModel(window, db);
-				await mainContentScreenModel.Initialize();
-				mainContentScreenModel.DatabaseClosed += MainContentScreenModelOnDatabaseClosed;
-				mainContentScreen = new MainContentScreen { DataContext = mainContentScreenModel };
-				CurrentScreen = mainContentScreen;
-			}
-
-			OnPropertyChanged(nameof(CurrentScreen));
-			OnPropertyChanged(nameof(Title));
-
-			window.Focus();
-		}
-	}
-
-	private void MainContentScreenModelOnDatabaseClosed(object? sender, EventArgs e) {
-		welcomeScreenModel.CloseDatabase();
-	}
-
-	public void Dispose() {
-		welcomeScreenModel.Dispose();
 		mainContentScreenModel?.Dispose();
-		db?.Dispose();
+		await DisposeState();
-		db = null;
 	}
 }

app/Desktop/Main/Pages/AdvancedPage.axaml

@@ -5,7 +5,8 @@
              xmlns:pages="clr-namespace:DHT.Desktop.Main.Pages"
              xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
-             x:Class="DHT.Desktop.Main.Pages.AdvancedPage">
+             x:Class="DHT.Desktop.Main.Pages.AdvancedPage"
+             x:DataType="pages:AdvancedPageModel">
 
     <Design.DataContext>
         <pages:AdvancedPageModel />

app/Desktop/Main/Pages/AdvancedPageModel.cs

@@ -1,39 +1,36 @@
 using System;
+using System.Threading.Tasks;
 using Avalonia.Controls;
 using DHT.Desktop.Dialogs.Message;
+using DHT.Desktop.Dialogs.Progress;
 using DHT.Desktop.Main.Controls;
-using DHT.Desktop.Server;
+using DHT.Server;
-using DHT.Server.Database;
-using DHT.Utils.Models;
 
 namespace DHT.Desktop.Main.Pages;
 
-sealed class AdvancedPageModel : BaseModel, IDisposable {
+sealed class AdvancedPageModel : IDisposable {
 	public ServerConfigurationPanelModel ServerConfigurationModel { get; }
-
+	
 	private readonly Window window;
-	private readonly IDatabaseFile db;
+	private readonly State state;
 
 	[Obsolete("Designer")]
-	public AdvancedPageModel() : this(null!, DummyDatabaseFile.Instance, new ServerManager(DummyDatabaseFile.Instance)) {}
+	public AdvancedPageModel() : this(null!, State.Dummy) {}
 
-	public AdvancedPageModel(Window window, IDatabaseFile db, ServerManager serverManager) {
+	public AdvancedPageModel(Window window, State state) {
 		this.window = window;
-		this.db = db;
+		this.state = state;
 
-		ServerConfigurationModel = new ServerConfigurationPanelModel(window, serverManager);
+		ServerConfigurationModel = new ServerConfigurationPanelModel(window, state);
-	}
-
-	public void Initialize() {
-		ServerConfigurationModel.Initialize();
 	}
 
 	public void Dispose() {
 		ServerConfigurationModel.Dispose();
 	}
 
-	public async void VacuumDatabase() {
+	public async Task VacuumDatabase() {
-		db.Vacuum();
+		const string Title = "Vacuum Database";
-		await Dialog.ShowOk(window, "Vacuum Database", "Done.");
+		await ProgressDialog.ShowIndeterminate(window, Title, "Vacuuming database...", _ => state.Db.Vacuum());
+		await Dialog.ShowOk(window, Title, "Done.");
 	}
 }

app/Desktop/Main/Pages/AttachmentsPageModel.cs

@@ -1,205 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.ComponentModel;
-using System.Threading;
-using Avalonia.Threading;
-using DHT.Desktop.Common;
-using DHT.Desktop.Main.Controls;
-using DHT.Server.Data;
-using DHT.Server.Data.Aggregations;
-using DHT.Server.Data.Filters;
-using DHT.Server.Database;
-using DHT.Server.Download;
-using DHT.Utils.Models;
-using DHT.Utils.Tasks;
-
-namespace DHT.Desktop.Main.Pages;
-
-sealed class AttachmentsPageModel : BaseModel, IDisposable {
-	private static readonly DownloadItemFilter EnqueuedItemFilter = new() {
-		IncludeStatuses = new HashSet<DownloadStatus> {
-			DownloadStatus.Enqueued
-		}
-	};
-
-	private bool isThreadDownloadButtonEnabled = true;
-
-	public string ToggleDownloadButtonText => downloadThread == null ? "Start Downloading" : "Stop Downloading";
-
-	public bool IsToggleDownloadButtonEnabled {
-		get => isThreadDownloadButtonEnabled;
-		set => Change(ref isThreadDownloadButtonEnabled, value);
-	}
-
-	public string DownloadMessage { get; set; } = "";
-	public double DownloadProgress => allItemsCount is null or 0 ? 0.0 : 100.0 * doneItemsCount / allItemsCount.Value;
-
-	public AttachmentFilterPanelModel FilterModel { get; }
-
-	private readonly StatisticsRow statisticsEnqueued = new ("Enqueued");
-	private readonly StatisticsRow statisticsDownloaded = new ("Downloaded");
-	private readonly StatisticsRow statisticsFailed = new ("Failed");
-	private readonly StatisticsRow statisticsSkipped = new ("Skipped");
-
-	public List<StatisticsRow> StatisticsRows {
-		get {
-			return new List<StatisticsRow> {
-				statisticsEnqueued,
-				statisticsDownloaded,
-				statisticsFailed,
-				statisticsSkipped
-			};
-		}
-	}
-
-	public bool IsDownloading => downloadThread != null;
-	public bool HasFailedDownloads => statisticsFailed.Items > 0;
-
-	private readonly IDatabaseFile db;
-	private readonly AsyncValueComputer<DownloadStatusStatistics>.Single downloadStatisticsComputer;
-	private BackgroundDownloadThread? downloadThread;
-
-	private int doneItemsCount;
-	private int? allItemsCount;
-
-	public AttachmentsPageModel() : this(DummyDatabaseFile.Instance) {}
-
-	public AttachmentsPageModel(IDatabaseFile db) {
-		this.db = db;
-		this.FilterModel = new AttachmentFilterPanelModel(db);
-
-		this.downloadStatisticsComputer = AsyncValueComputer<DownloadStatusStatistics>.WithResultProcessor(UpdateStatistics).WithOutdatedResults().BuildWithComputer(db.GetDownloadStatusStatistics);
-		this.downloadStatisticsComputer.Recompute();
-
-		db.Statistics.PropertyChanged += OnDbStatisticsChanged;
-	}
-
-	public void Dispose() {
-		db.Statistics.PropertyChanged -= OnDbStatisticsChanged;
-
-		FilterModel.Dispose();
-		DisposeDownloadThread();
-	}
-
-	private void OnDbStatisticsChanged(object? sender, PropertyChangedEventArgs e) {
-		if (e.PropertyName == nameof(DatabaseStatistics.TotalAttachments)) {
-			if (IsDownloading) {
-				EnqueueDownloadItems();
-			}
-			else {
-				downloadStatisticsComputer.Recompute();
-			}
-		}
-		else if (e.PropertyName == nameof(DatabaseStatistics.TotalDownloads)) {
-			downloadStatisticsComputer.Recompute();
-		}
-	}
-
-	private void EnqueueDownloadItems() {
-		var filter = FilterModel.CreateFilter();
-		filter.DownloadItemRule = AttachmentFilter.DownloadItemRules.OnlyNotPresent;
-		db.EnqueueDownloadItems(filter);
-
-		downloadStatisticsComputer.Recompute();
-	}
-
-	private void UpdateStatistics(DownloadStatusStatistics statusStatistics) {
-		var hadFailedDownloads = HasFailedDownloads;
-
-		statisticsEnqueued.Items = statusStatistics.EnqueuedCount;
-		statisticsEnqueued.Size = statusStatistics.EnqueuedSize;
-
-		statisticsDownloaded.Items = statusStatistics.SuccessfulCount;
-		statisticsDownloaded.Size = statusStatistics.SuccessfulSize;
-
-		statisticsFailed.Items = statusStatistics.FailedCount;
-		statisticsFailed.Size = statusStatistics.FailedSize;
-
-		statisticsSkipped.Items = statusStatistics.SkippedCount;
-		statisticsSkipped.Size = statusStatistics.SkippedSize;
-
-		OnPropertyChanged(nameof(StatisticsRows));
-
-		if (hadFailedDownloads != HasFailedDownloads) {
-			OnPropertyChanged(nameof(HasFailedDownloads));
-		}
-
-		allItemsCount = doneItemsCount + statisticsEnqueued.Items;
-		UpdateDownloadMessage();
-	}
-
-	private void UpdateDownloadMessage() {
-		DownloadMessage = IsDownloading ? doneItemsCount.Format() + " / " + (allItemsCount?.Format() ?? "?") : "";
-
-		OnPropertyChanged(nameof(DownloadMessage));
-		OnPropertyChanged(nameof(DownloadProgress));
-	}
-
-	private void DownloadThreadOnOnItemFinished(object? sender, DownloadItem e) {
-		Interlocked.Increment(ref doneItemsCount);
-
-		Dispatcher.UIThread.Invoke(UpdateDownloadMessage);
-		downloadStatisticsComputer.Recompute();
-	}
-
-	private void DownloadThreadOnOnServerStopped(object? sender, EventArgs e) {
-		downloadStatisticsComputer.Recompute();
-		IsToggleDownloadButtonEnabled = true;
-	}
-
-	public void OnClickToggleDownload() {
-		if (downloadThread == null) {
-			EnqueueDownloadItems();
-			downloadThread = new BackgroundDownloadThread(db);
-			downloadThread.OnItemFinished += DownloadThreadOnOnItemFinished;
-			downloadThread.OnServerStopped += DownloadThreadOnOnServerStopped;
-		}
-		else {
-			IsToggleDownloadButtonEnabled = false;
-			DisposeDownloadThread();
-
-			db.RemoveDownloadItems(EnqueuedItemFilter, FilterRemovalMode.RemoveMatching);
-
-			doneItemsCount = 0;
-			allItemsCount = null;
-			UpdateDownloadMessage();
-		}
-
-		OnPropertyChanged(nameof(ToggleDownloadButtonText));
-		OnPropertyChanged(nameof(IsDownloading));
-	}
-
-	public void OnClickRetryFailedDownloads() {
-		var allExceptFailedFilter = new DownloadItemFilter {
-			IncludeStatuses = new HashSet<DownloadStatus> {
-				DownloadStatus.Enqueued,
-				DownloadStatus.Success
-			}
-		};
-
-		db.RemoveDownloadItems(allExceptFailedFilter, FilterRemovalMode.KeepMatching);
-
-		if (IsDownloading) {
-			EnqueueDownloadItems();
-		}
-	}
-
-	private void DisposeDownloadThread() {
-		if (downloadThread != null) {
-			downloadThread.OnItemFinished -= DownloadThreadOnOnItemFinished;
-			downloadThread.StopThread();
-		}
-
-		downloadThread = null;
-	}
-
-	public sealed class StatisticsRow {
-		public string State { get; }
-		public int Items { get; set; }
-		public ulong? Size { get; set; }
-
-		public StatisticsRow(string state) {
-			State = state;
-		}
-	}
-}

app/Desktop/Main/Pages/DatabasePage.axaml

@@ -4,7 +4,8 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:pages="clr-namespace:DHT.Desktop.Main.Pages"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
-             x:Class="DHT.Desktop.Main.Pages.DatabasePage">
+             x:Class="DHT.Desktop.Main.Pages.DatabasePage"
+             x:DataType="pages:DatabasePageModel">
 
     <Design.DataContext>
         <pages:DatabasePageModel />

app/Desktop/Main/Pages/DatabasePageModel.cs

@@ -14,15 +14,16 @@ using DHT.Desktop.Dialogs.File;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Dialogs.Progress;
 using DHT.Desktop.Dialogs.TextBox;
+using DHT.Server;
 using DHT.Server.Data;
 using DHT.Server.Database;
 using DHT.Server.Database.Import;
+using DHT.Server.Database.Sqlite.Schema;
 using DHT.Utils.Logging;
-using DHT.Utils.Models;
 
-namespace DHT.Desktop.Main.Pages; 
+namespace DHT.Desktop.Main.Pages;
 
-sealed class DatabasePageModel : BaseModel {
+sealed class DatabasePageModel {
 	private static readonly Log Log = Log.ForType<DatabasePageModel>();
 
 	public IDatabaseFile Db { get; }
@@ -32,14 +33,14 @@ sealed class DatabasePageModel : BaseModel {
 	private readonly Window window;
 
 	[Obsolete("Designer")]
-	public DatabasePageModel() : this(null!, DummyDatabaseFile.Instance) {}
+	public DatabasePageModel() : this(null!, State.Dummy) {}
 
-	public DatabasePageModel(Window window, IDatabaseFile db) {
+	public DatabasePageModel(Window window, State state) {
 		this.window = window;
-		this.Db = db;
+		this.Db = state.Db;
 	}
 
-	public async void OpenDatabaseFolder() {
+	public async Task OpenDatabaseFolder() {
 		string file = Db.Path;
 		string? folder = Path.GetDirectoryName(file);
 
@@ -70,69 +71,77 @@ sealed class DatabasePageModel : BaseModel {
 		DatabaseClosed?.Invoke(this, EventArgs.Empty);
 	}
 
-	public async void MergeWithDatabase() {
+	public async Task MergeWithDatabase() {
 		var paths = await DatabaseGui.NewOpenDatabaseFilesDialog(window, Path.GetDirectoryName(Db.Path));
-		if (paths.Length == 0) {
+		if (paths.Length > 0) {
-			return;
+			await ProgressDialog.Show(window, "Database Merge", async (dialog, callback) => await MergeWithDatabaseFromPaths(Db, paths, dialog, callback));
 		}
-
-		ProgressDialog progressDialog = new ProgressDialog();
-		progressDialog.DataContext = new ProgressDialogModel(async callback => await MergeWithDatabaseFromPaths(Db, paths, progressDialog, callback)) {
-			Title = "Database Merge"
-		};
-
-		await progressDialog.ShowDialog(window);
 	}
 
 	private static async Task MergeWithDatabaseFromPaths(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback) {
-		int total = paths.Length;
+		var schemaUpgradeCallbacks = new SchemaUpgradeCallbacks(dialog, paths.Length);
-
-		DialogResult.YesNo? upgradeResult = null;
-
-		async Task<bool> CheckCanUpgradeDatabase() {
-			upgradeResult ??= total > 1
-				                  ? await DatabaseGui.ShowCanUpgradeMultipleDatabaseDialog(dialog)
-				                  : await DatabaseGui.ShowCanUpgradeDatabaseDialog(dialog);
-
-			return DialogResult.YesNo.Yes == upgradeResult;
-		}
 
 		await PerformImport(target, paths, dialog, callback, "Database Merge", "Database Error", "database file", async path => {
-			SynchronizationContext? prevSyncContext = SynchronizationContext.Current;
+			IDatabaseFile? db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, dialog, schemaUpgradeCallbacks);
-			SynchronizationContext.SetSynchronizationContext(new AvaloniaSynchronizationContext());
-			IDatabaseFile? db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, dialog, CheckCanUpgradeDatabase);
-			SynchronizationContext.SetSynchronizationContext(prevSyncContext);
 
 			if (db == null) {
 				return false;
 			}
 
 			try {
-				target.AddFrom(db);
+				await target.AddFrom(db);
 				return true;
 			} finally {
-				db.Dispose();
+				await db.DisposeAsync();
 			}
 		});
 	}
 
-	public async void ImportLegacyArchive() {
+	private sealed class SchemaUpgradeCallbacks : ISchemaUpgradeCallbacks {
+		private readonly ProgressDialog dialog;
+		private readonly int total;
+		private bool? decision;
+
+		public SchemaUpgradeCallbacks(ProgressDialog dialog, int total) {
+			this.total = total;
+			this.dialog = dialog;
+		}
+
+		public async Task<bool> CanUpgrade() {
+			return decision ??= (total > 1
+				                     ? await DatabaseGui.ShowCanUpgradeMultipleDatabaseDialog(dialog)
+				                     : await DatabaseGui.ShowCanUpgradeDatabaseDialog(dialog)) == DialogResult.YesNo.Yes;
+		}
+
+		public Task Start(int versionSteps, Func<ISchemaUpgradeCallbacks.IProgressReporter, Task> doUpgrade) {
+			return doUpgrade(new NullReporter());
+		}
+
+		private sealed class NullReporter : ISchemaUpgradeCallbacks.IProgressReporter {
+			public Task NextVersion() {
+				return Task.CompletedTask;
+			}
+
+			public Task MainWork(string message, int finishedItems, int totalItems) {
+				return Task.CompletedTask;
+			}
+
+			public Task SubWork(string message, int finishedItems, int totalItems) {
+				return Task.CompletedTask;
+			}
+		}
+	}
+
+	public async Task ImportLegacyArchive() {
 		var paths = await window.StorageProvider.OpenFiles(new FilePickerOpenOptions {
 			Title = "Open Legacy DHT Archive",
 			SuggestedStartLocation = await FileDialogs.GetSuggestedStartLocation(window, Path.GetDirectoryName(Db.Path)),
 			AllowMultiple = true
 		});
-			
+
-		if (paths.Length == 0) {
+		if (paths.Length > 0) {
-			return;
+			await ProgressDialog.Show(window, "Legacy Archive Import", async (dialog, callback) => await ImportLegacyArchiveFromPaths(Db, paths, dialog, callback));
 		}
-
-		ProgressDialog progressDialog = new ProgressDialog();
-		progressDialog.DataContext = new ProgressDialogModel(async callback => await ImportLegacyArchiveFromPaths(Db, paths, progressDialog, callback)) {
-			Title = "Legacy Archive Import"
-		};
-
-		await progressDialog.ShowDialog(window);
 	}
 
 	private static async Task ImportLegacyArchiveFromPaths(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback) {
@@ -140,7 +149,7 @@ sealed class DatabasePageModel : BaseModel {
 
 		await PerformImport(target, paths, dialog, callback, "Legacy Archive Import", "Legacy Archive Error", "archive file", async path => {
 			await using var jsonStream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
-				
+
 			return await LegacyArchiveImport.Read(jsonStream, target, fakeSnowflake, async servers => {
 				SynchronizationContext? prevSyncContext = SynchronizationContext.Current;
 				SynchronizationContext.SetSynchronizationContext(new AvaloniaSynchronizationContext());
@@ -155,7 +164,7 @@ sealed class DatabasePageModel : BaseModel {
 		static bool IsValidSnowflake(string value) {
 			return string.IsNullOrEmpty(value) || ulong.TryParse(value, out _);
 		}
-			
+
 		var items = new List<TextBoxItem<DHT.Server.Data.Server>>();
 
 		foreach (var server in servers.OrderBy(static server => server.Type).ThenBy(static server => server.Name)) {
@@ -184,7 +193,7 @@ sealed class DatabasePageModel : BaseModel {
 
 	private static async Task PerformImport(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback, string neutralDialogTitle, string errorDialogTitle, string itemName, Func<string, Task<bool>> performImport) {
 		int total = paths.Length;
-		var oldStatistics = target.SnapshotStatistics();
+		var oldStatistics = await DatabaseStatistics.Take(target);
 
 		int successful = 0;
 		int finished = 0;
@@ -215,14 +224,26 @@ sealed class DatabasePageModel : BaseModel {
 			return;
 		}
 
-		await Dialog.ShowOk(dialog, neutralDialogTitle, GetImportDialogMessage(oldStatistics, target.SnapshotStatistics(), successful, total, itemName));
+		var newStatistics = await DatabaseStatistics.Take(target);
+		await Dialog.ShowOk(dialog, neutralDialogTitle, GetImportDialogMessage(oldStatistics, newStatistics, successful, total, itemName));
 	}
 
-	private static string GetImportDialogMessage(DatabaseStatisticsSnapshot oldStatistics, DatabaseStatisticsSnapshot newStatistics, int successfulItems, int totalItems, string itemName) {
+	private sealed record DatabaseStatistics(long ServerCount, long ChannelCount, long UserCount, long MessageCount) {
-		long newServers = newStatistics.TotalServers - oldStatistics.TotalServers;
+		public static async Task<DatabaseStatistics> Take(IDatabaseFile db) {
-		long newChannels = newStatistics.TotalChannels - oldStatistics.TotalChannels;
+			return new DatabaseStatistics(
-		long newUsers = newStatistics.TotalUsers - oldStatistics.TotalUsers;
+				await db.Servers.Count(),
-		long newMessages = newStatistics.TotalMessages - oldStatistics.TotalMessages;
+				await db.Channels.Count(),
+				await db.Users.Count(),
+				await db.Messages.Count()
+			);
+		}
+	}
+
+	private static string GetImportDialogMessage(DatabaseStatistics oldStatistics, DatabaseStatistics newStatistics, int successfulItems, int totalItems, string itemName) {
+		long newServers = newStatistics.ServerCount - oldStatistics.ServerCount;
+		long newChannels = newStatistics.ChannelCount - oldStatistics.ChannelCount;
+		long newUsers = newStatistics.UserCount - oldStatistics.UserCount;
+		long newMessages = newStatistics.MessageCount - oldStatistics.MessageCount;
 
 		StringBuilder message = new StringBuilder();
 		message.Append("Processed ");

app/Desktop/Main/Pages/DebugPage.axaml

@@ -4,7 +4,8 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:pages="clr-namespace:DHT.Desktop.Main.Pages"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
-             x:Class="DHT.Desktop.Main.Pages.DebugPage">
+             x:Class="DHT.Desktop.Main.Pages.DebugPage"
+             x:DataType="pages:DebugPageModel">
     
     <Design.DataContext>
         <pages:DebugPageModel />

app/Desktop/Main/Pages/DebugPageModel.cs

@@ -6,180 +6,168 @@ using System.Threading.Tasks;
 using Avalonia.Controls;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Dialogs.Progress;
+using DHT.Server;
 using DHT.Server.Data;
-using DHT.Server.Database;
 using DHT.Server.Service;
-using DHT.Utils.Models;
 
-namespace DHT.Desktop.Main.Pages {
+namespace DHT.Desktop.Main.Pages;
-	sealed class DebugPageModel : BaseModel {
-		public string GenerateChannels { get; set; } = "0";
-		public string GenerateUsers { get; set; } = "0";
-		public string GenerateMessages { get; set; } = "0";
 
-		private readonly Window window;
+sealed class DebugPageModel {
-		private readonly IDatabaseFile db;
+	public string GenerateChannels { get; set; } = "0";
+	public string GenerateUsers { get; set; } = "0";
+	public string GenerateMessages { get; set; } = "0";
 
-		[Obsolete("Designer")]
+	private readonly Window window;
-		public DebugPageModel() : this(null!, DummyDatabaseFile.Instance) {}
+	private readonly State state;
 
-		public DebugPageModel(Window window, IDatabaseFile db) {
+	[Obsolete("Designer")]
-			this.window = window;
+	public DebugPageModel() : this(null!, State.Dummy) {}
-			this.db = db;
+
+	public DebugPageModel(Window window, State state) {
+		this.window = window;
+		this.state = state;
+	}
+
+	public async void OnClickAddRandomDataToDatabase() {
+		if (!int.TryParse(GenerateChannels, out int channels) || channels < 1) {
+			await Dialog.ShowOk(window, "Generate Random Data", "Amount of channels must be at least 1!");
+			return;
 		}
 
-		public async void OnClickAddRandomDataToDatabase() {
+		if (!int.TryParse(GenerateUsers, out int users) || users < 1) {
-			if (!int.TryParse(GenerateChannels, out int channels) || channels < 1) {
+			await Dialog.ShowOk(window, "Generate Random Data", "Amount of users must be at least 1!");
-				await Dialog.ShowOk(window, "Generate Random Data", "Amount of channels must be at least 1!");
+			return;
-				return;
-			}
-
-			if (!int.TryParse(GenerateUsers, out int users) || users < 1) {
-				await Dialog.ShowOk(window, "Generate Random Data", "Amount of users must be at least 1!");
-				return;
-			}
-
-			if (!int.TryParse(GenerateMessages, out int messages) || messages < 1) {
-				await Dialog.ShowOk(window, "Generate Random Data", "Amount of messages must be at least 1!");
-				return;
-			}
-
-			ProgressDialog progressDialog = new ProgressDialog {
-				DataContext = new ProgressDialogModel(async callback => await GenerateRandomData(channels, users, messages, callback)) {
-					Title = "Generating Random Data"
-				}
-			};
-
-			await progressDialog.ShowDialog(window);
 		}
 
-		private const int BatchSize = 500;
+		if (!int.TryParse(GenerateMessages, out int messages) || messages < 1) {
-
+			await Dialog.ShowOk(window, "Generate Random Data", "Amount of messages must be at least 1!");
-		private async Task GenerateRandomData(int channelCount, int userCount, int messageCount, IProgressCallback callback) {
+			return;
-			int batchCount = (messageCount + BatchSize - 1) / BatchSize;
-			await callback.Update("Adding messages in batches of " + BatchSize, 0, batchCount);
-
-			var rand = new Random();
-			var server = new DHT.Server.Data.Server {
-				Id = RandomId(rand),
-				Name = RandomName("s"),
-				Type = ServerType.Server,
-			};
-
-			var channels = Enumerable.Range(0, channelCount).Select(i => new Channel {
-				Id = RandomId(rand),
-				Server = server.Id,
-				Name = RandomName("c"),
-				ParentId = null,
-				Position = i,
-				Topic = RandomText(rand, 10),
-				Nsfw = rand.Next(4) == 0,
-			}).ToArray();
-
-			var users = Enumerable.Range(0, userCount).Select(_ => new User {
-				Id = RandomId(rand),
-				Name = RandomName("u"),
-				AvatarUrl = null,
-				Discriminator = rand.Next(0, 9999).ToString(),
-			}).ToArray();
-
-			db.AddServer(server);
-			db.AddUsers(users);
-
-			foreach (var channel in channels) {
-				db.AddChannel(channel);
-			}
-
-			var now = DateTimeOffset.Now;
-			int batchIndex = 0;
-
-			while (messageCount > 0) {
-				int hourOffset = batchIndex;
-
-				var messages = Enumerable.Range(0, Math.Min(messageCount, BatchSize)).Select(i => {
-					DateTimeOffset time = now.AddHours(hourOffset).AddMinutes(i * 60.0 / BatchSize);
-					DateTimeOffset? edit = rand.Next(100) == 0 ? time.AddSeconds(rand.Next(1, 60)) : null;
-
-					var timeMillis = time.ToUnixTimeMilliseconds();
-					var editMillis = edit?.ToUnixTimeMilliseconds();
-
-					return new Message {
-						Id = (ulong) timeMillis,
-						Sender = RandomBiasedIndex(rand, users).Id,
-						Channel = RandomBiasedIndex(rand, channels).Id,
-						Text = RandomText(rand, 100),
-						Timestamp = timeMillis,
-						EditTimestamp = editMillis,
-						RepliedToId = null,
-						Attachments = ImmutableArray<Attachment>.Empty,
-						Embeds = ImmutableArray<Embed>.Empty,
-						Reactions = ImmutableArray<Reaction>.Empty,
-					};
-				}).ToArray();
-
-				db.AddMessages(messages);
-
-				messageCount -= BatchSize;
-				await callback.Update("Adding messages in batches of " + BatchSize, ++batchIndex, batchCount);
-			}
 		}
 
-		private static ulong RandomId(Random rand) {
+		await ProgressDialog.Show(window, "Generating Random Data", async (_, callback) => await GenerateRandomData(channels, users, messages, callback));
-			ulong h = unchecked((ulong) rand.Next());
+	}
-			ulong l = unchecked((ulong) rand.Next());
-			return (h << 32) | l;
-		}
 
-		private static string RandomName(string prefix) {
+	private const int BatchSize = 500;
-			return prefix + "-" + ServerUtils.GenerateRandomToken(5);
-		}
 
-		private static T RandomBiasedIndex<T>(Random rand, T[] options) {
+	private async Task GenerateRandomData(int channelCount, int userCount, int messageCount, IProgressCallback callback) {
-			return options[(int) Math.Floor(options.Length * rand.NextDouble() * rand.NextDouble())];
+		int batchCount = (messageCount + BatchSize - 1) / BatchSize;
-		}
+		await callback.Update("Adding messages in batches of " + BatchSize, 0, batchCount);
 
-		private static readonly string[] RandomWords = {
+		var rand = new Random();
-			"apple", "apricot", "artichoke", "arugula", "asparagus", "avocado",
+		var server = new DHT.Server.Data.Server {
-			"banana", "bean", "beechnut", "beet", "blackberry", "blackcurrant", "blueberry", "boysenberry", "bramble", "broccoli",
+			Id = RandomId(rand),
-			"cabbage", "cacao", "cantaloupe", "caper", "carambola", "carrot", "cauliflower", "celery", "chard", "cherry", "chokeberry", "citron", "clementine", "coconut", "corn", "crabapple", "cranberry", "cucumber", "currant",
+			Name = RandomName("s"),
-			"daikon", "date", "dewberry", "durian",
+			Type = ServerType.Server,
-			"edamame", "eggplant", "elderberry", "endive",
-			"fig",
-			"garlic", "ginger", "gooseberry", "grape", "grapefruit", "guava",
-			"honeysuckle", "horseradish", "huckleberry",
-			"jackfruit", "jicama",
-			"kale", "kiwi", "kohlrabi", "kumquat",
-			"leek", "lemon", "lentil", "lettuce", "lime",
-			"mandarin", "mango", "mushroom", "myrtle",
-			"nectarine", "nut",
-			"olive", "okra", "onion", "orange",
-			"papaya", "parsnip", "pawpaw", "peach", "pear", "pea", "pepper", "persimmon", "pineapple", "plum", "plantain", "pomegranate", "pomelo", "potato", "prune", "pumpkin",
-			"quandong", "quinoa",
-			"radicchio", "radish", "raisin", "raspberry", "redcurrant", "rhubarb", "rutabaga",
-			"spinach", "strawberry", "squash",
-			"tamarind", "tangerine", "tomatillo", "tomato", "turnip",
-			"vanilla",
-			"watercress", "watermelon",
-			"yam",
-			"zucchini",
 		};
 
-		private static string RandomText(Random rand, int maxWords) {
+		var channels = Enumerable.Range(0, channelCount).Select(i => new Channel {
-			int wordCount = 1 + (int) Math.Floor(maxWords * Math.Pow(rand.NextDouble(), 3));
+			Id = RandomId(rand),
-			return string.Join(' ', Enumerable.Range(0, wordCount).Select(_ => RandomWords[rand.Next(RandomWords.Length)]));
+			Server = server.Id,
+			Name = RandomName("c"),
+			ParentId = null,
+			Position = i,
+			Topic = RandomText(rand, 10),
+			Nsfw = rand.Next(4) == 0,
+		}).ToArray();
+
+		var users = Enumerable.Range(0, userCount).Select(_ => new User {
+			Id = RandomId(rand),
+			Name = RandomName("u"),
+			AvatarUrl = null,
+			Discriminator = rand.Next(0, 9999).ToString(),
+		}).ToArray();
+
+		await state.Db.Users.Add(users);
+		await state.Db.Servers.Add([server]);
+		await state.Db.Channels.Add(channels);
+
+		var now = DateTimeOffset.Now;
+		int batchIndex = 0;
+
+		while (messageCount > 0) {
+			int hourOffset = batchIndex;
+
+			var messages = Enumerable.Range(0, Math.Min(messageCount, BatchSize)).Select(i => {
+				DateTimeOffset time = now.AddHours(hourOffset).AddMinutes(i * 60.0 / BatchSize);
+				DateTimeOffset? edit = rand.Next(100) == 0 ? time.AddSeconds(rand.Next(1, 60)) : null;
+
+				var timeMillis = time.ToUnixTimeMilliseconds();
+				var editMillis = edit?.ToUnixTimeMilliseconds();
+
+				return new Message {
+					Id = (ulong) timeMillis,
+					Sender = RandomBiasedIndex(rand, users).Id,
+					Channel = RandomBiasedIndex(rand, channels).Id,
+					Text = RandomText(rand, 100),
+					Timestamp = timeMillis,
+					EditTimestamp = editMillis,
+					RepliedToId = null,
+					Attachments = ImmutableList<Attachment>.Empty,
+					Embeds = ImmutableList<Embed>.Empty,
+					Reactions = ImmutableList<Reaction>.Empty,
+				};
+			}).ToArray();
+
+			await state.Db.Messages.Add(messages);
+
+			messageCount -= BatchSize;
+			await callback.Update("Adding messages in batches of " + BatchSize, ++batchIndex, batchCount);
 		}
 	}
+
+	private static ulong RandomId(Random rand) {
+		ulong h = unchecked((ulong) rand.Next());
+		ulong l = unchecked((ulong) rand.Next());
+		return (h << 32) | l;
+	}
+
+	private static string RandomName(string prefix) {
+		return prefix + "-" + ServerUtils.GenerateRandomToken(5);
+	}
+
+	private static T RandomBiasedIndex<T>(Random rand, T[] options) {
+		return options[(int) Math.Floor(options.Length * rand.NextDouble() * rand.NextDouble())];
+	}
+
+	private static readonly string[] RandomWords = [
+		"apple", "apricot", "artichoke", "arugula", "asparagus", "avocado",
+		"banana", "bean", "beechnut", "beet", "blackberry", "blackcurrant", "blueberry", "boysenberry", "bramble", "broccoli",
+		"cabbage", "cacao", "cantaloupe", "caper", "carambola", "carrot", "cauliflower", "celery", "chard", "cherry", "chokeberry", "citron", "clementine", "coconut", "corn", "crabapple", "cranberry", "cucumber", "currant",
+		"daikon", "date", "dewberry", "durian",
+		"edamame", "eggplant", "elderberry", "endive",
+		"fig",
+		"garlic", "ginger", "gooseberry", "grape", "grapefruit", "guava",
+		"honeysuckle", "horseradish", "huckleberry",
+		"jackfruit", "jicama",
+		"kale", "kiwi", "kohlrabi", "kumquat",
+		"leek", "lemon", "lentil", "lettuce", "lime",
+		"mandarin", "mango", "mushroom", "myrtle",
+		"nectarine", "nut",
+		"olive", "okra", "onion", "orange",
+		"papaya", "parsnip", "pawpaw", "peach", "pear", "pea", "pepper", "persimmon", "pineapple", "plum", "plantain", "pomegranate", "pomelo", "potato", "prune", "pumpkin",
+		"quandong", "quinoa",
+		"radicchio", "radish", "raisin", "raspberry", "redcurrant", "rhubarb", "rutabaga",
+		"spinach", "strawberry", "squash",
+		"tamarind", "tangerine", "tomatillo", "tomato", "turnip",
+		"vanilla",
+		"watercress", "watermelon",
+		"yam",
+		"zucchini"
+	];
+
+	private static string RandomText(Random rand, int maxWords) {
+		int wordCount = 1 + (int) Math.Floor(maxWords * Math.Pow(rand.NextDouble(), 3));
+		return string.Join(' ', Enumerable.Range(0, wordCount).Select(_ => RandomWords[rand.Next(RandomWords.Length)]));
+	}
 }
 #else
-using DHT.Utils.Models;
+namespace DHT.Desktop.Main.Pages;
 
-namespace DHT.Desktop.Main.Pages {
+sealed class DebugPageModel {
-	sealed class DebugPageModel : BaseModel {
+	public string GenerateChannels { get; set; } = "0";
-		public string GenerateChannels { get; set; } = "0";
+	public string GenerateUsers { get; set; } = "0";
-		public string GenerateUsers { get; set; } = "0";
+	public string GenerateMessages { get; set; } = "0";
-		public string GenerateMessages { get; set; } = "0";
 
-		public void OnClickAddRandomDataToDatabase() {}
+	public void OnClickAddRandomDataToDatabase() {}
-	}
 }
 #endif

app/Desktop/Main/Pages/DownloadsPage.axaml

@@ -5,10 +5,11 @@
              xmlns:pages="clr-namespace:DHT.Desktop.Main.Pages"
              xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
-             x:Class="DHT.Desktop.Main.Pages.AttachmentsPage">
+             x:Class="DHT.Desktop.Main.Pages.DownloadsPage"
+             x:DataType="pages:DownloadsPageModel">
 
     <Design.DataContext>
-        <pages:AttachmentsPageModel />
+        <pages:DownloadsPageModel />
     </Design.DataContext>
 
     <UserControl.Styles>
@@ -30,24 +31,20 @@
     </UserControl.Styles>
 
     <StackPanel Orientation="Vertical" Spacing="20">
-        <DockPanel>
+        <Button Command="{Binding OnClickToggleDownload}" Content="{Binding ToggleDownloadButtonText}" IsEnabled="{Binding IsToggleDownloadButtonEnabled}" />
-            <Button Command="{Binding OnClickToggleDownload}" Content="{Binding ToggleDownloadButtonText}" IsEnabled="{Binding IsToggleDownloadButtonEnabled}" DockPanel.Dock="Left" />
+        <controls:DownloadItemFilterPanel DataContext="{Binding FilterModel}" IsEnabled="{Binding !$parent[UserControl].((pages:DownloadsPageModel)DataContext).IsDownloading}" />
-            <TextBlock Text="{Binding DownloadMessage}" Margin="10 0 0 0" VerticalAlignment="Center" DockPanel.Dock="Left" />
-            <ProgressBar Value="{Binding DownloadProgress}" IsVisible="{Binding IsDownloading}" Margin="15 0" VerticalAlignment="Center" DockPanel.Dock="Right" />
-        </DockPanel>
-        <controls:AttachmentFilterPanel DataContext="{Binding FilterModel}" IsEnabled="{Binding !DataContext.IsDownloading, RelativeSource={RelativeSource AncestorType=UserControl}}" />
         <StackPanel Orientation="Vertical" Spacing="12">
             <Expander Header="Download Status" IsExpanded="True">
                 <DataGrid ItemsSource="{Binding StatisticsRows}" AutoGenerateColumns="False" CanUserReorderColumns="False" CanUserResizeColumns="False" CanUserSortColumns="False" IsReadOnly="True">
                     <DataGrid.Columns>
-                        <DataGridTextColumn Header="State" Binding="{Binding State}" Width="*" />
+                        <DataGridTextColumn Header="State" Binding="{Binding State, Mode=OneWay}" Width="*" />
-                        <DataGridTextColumn Header="Attachments" Binding="{Binding Items, Converter={StaticResource NumberValueConverter}}" Width="*" CellStyleClasses="right" />
+                        <DataGridTextColumn Header="Files" Binding="{Binding Items, Mode=OneWay, Converter={StaticResource NumberValueConverter}}" Width="*" CellStyleClasses="right" />
-                        <DataGridTextColumn Header="Size" Binding="{Binding Size, Converter={StaticResource BytesValueConverter}}" Width="*" CellStyleClasses="right" />
+                        <DataGridTextColumn Header="Size" Binding="{Binding SizeText, Mode=OneWay}" Width="*" CellStyleClasses="right" />
                     </DataGrid.Columns>
                 </DataGrid>
             </Expander>
             <StackPanel Orientation="Horizontal" Spacing="10">
-                <Button Command="{Binding OnClickRetryFailedDownloads}" IsEnabled="{Binding HasFailedDownloads}">Retry Failed Downloads</Button>
+                <Button Command="{Binding OnClickRetryFailedDownloads}" IsEnabled="{Binding IsRetryFailedOnDownloadsButtonEnabled}">Retry Failed Downloads</Button>
             </StackPanel>
         </StackPanel>
     </StackPanel>

app/Desktop/Main/Pages/DownloadsPage.axaml.cs

@@ -4,8 +4,8 @@ using Avalonia.Controls;
 namespace DHT.Desktop.Main.Pages;
 
 [SuppressMessage("ReSharper", "MemberCanBeInternal")]
-public sealed partial class AttachmentsPage : UserControl {
+public sealed partial class DownloadsPage : UserControl {
-	public AttachmentsPage() {
+	public DownloadsPage() {
 		InitializeComponent();
 	}
 }

app/Desktop/Main/Pages/DownloadsPageModel.cs

@@ -0,0 +1,186 @@
+using System;
+using System.Collections.ObjectModel;
+using System.Reactive.Linq;
+using System.Threading.Tasks;
+using Avalonia.ReactiveUI;
+using CommunityToolkit.Mvvm.ComponentModel;
+using DHT.Desktop.Common;
+using DHT.Desktop.Main.Controls;
+using DHT.Server;
+using DHT.Server.Data.Aggregations;
+using DHT.Server.Data.Filters;
+using DHT.Server.Download;
+using DHT.Utils.Logging;
+using DHT.Utils.Tasks;
+
+namespace DHT.Desktop.Main.Pages;
+
+sealed partial class DownloadsPageModel : ObservableObject, IDisposable {
+	private static readonly Log Log = Log.ForType<DownloadsPageModel>();
+
+	[ObservableProperty(Setter = Access.Private)]
+	private bool isToggleDownloadButtonEnabled = true;
+
+	public string ToggleDownloadButtonText => IsDownloading ? "Stop Downloading" : "Start Downloading";
+
+	[ObservableProperty(Setter = Access.Private)]
+	[NotifyPropertyChangedFor(nameof(IsRetryFailedOnDownloadsButtonEnabled))]
+	private bool isRetryingFailedDownloads = false;
+
+	[ObservableProperty(Setter = Access.Private)]
+	[NotifyPropertyChangedFor(nameof(IsRetryFailedOnDownloadsButtonEnabled))]
+	private bool hasFailedDownloads;
+
+	public bool IsRetryFailedOnDownloadsButtonEnabled => !IsRetryingFailedDownloads && HasFailedDownloads;
+
+	[ObservableProperty(Setter = Access.Private)]
+	private string downloadMessage = "";
+
+	public DownloadItemFilterPanelModel FilterModel { get; }
+
+	private readonly StatisticsRow statisticsPending = new ("Pending");
+	private readonly StatisticsRow statisticsDownloaded = new ("Downloaded");
+	private readonly StatisticsRow statisticsFailed = new ("Failed");
+	private readonly StatisticsRow statisticsSkipped = new ("Skipped");
+
+	public ObservableCollection<StatisticsRow> StatisticsRows { get; }
+
+	public bool IsDownloading => state.Downloader.IsDownloading;
+
+	private readonly State state;
+	private readonly ThrottledTask<DownloadStatusStatistics> downloadStatisticsTask;
+	private readonly IDisposable downloadItemCountSubscription;
+	
+	private IDisposable? finishedItemsSubscription;
+	private DownloadItemFilter? currentDownloadFilter;
+
+	public DownloadsPageModel() : this(State.Dummy) {}
+
+	public DownloadsPageModel(State state) {
+		this.state = state;
+
+		FilterModel = new DownloadItemFilterPanelModel(state);
+		
+		StatisticsRows = [
+			statisticsPending,
+			statisticsDownloaded,
+			statisticsFailed,
+			statisticsSkipped
+		];
+
+		downloadStatisticsTask = new ThrottledTask<DownloadStatusStatistics>(Log, UpdateStatistics, TaskScheduler.FromCurrentSynchronizationContext());
+		downloadItemCountSubscription = state.Db.Downloads.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnDownloadCountChanged);
+
+		RecomputeDownloadStatistics();
+	}
+
+	public void Dispose() {
+		finishedItemsSubscription?.Dispose();
+		
+		downloadItemCountSubscription.Dispose();
+		downloadStatisticsTask.Dispose();
+
+		FilterModel.Dispose();
+	}
+
+	private void OnDownloadCountChanged(long newDownloadCount) {
+		RecomputeDownloadStatistics();
+	}
+
+	public async Task OnClickToggleDownload() {
+		IsToggleDownloadButtonEnabled = false;
+
+		if (IsDownloading) {
+			await state.Downloader.Stop();
+			await state.Db.Downloads.MoveDownloadingItemsBackToQueue();
+
+			finishedItemsSubscription?.Dispose();
+			finishedItemsSubscription = null;
+			
+			currentDownloadFilter = null;
+		}
+		else {
+			await state.Db.Downloads.MoveDownloadingItemsBackToQueue();
+			
+			var finishedItems = await state.Downloader.Start(currentDownloadFilter = FilterModel.CreateFilter());
+			finishedItemsSubscription = finishedItems.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnItemFinished);
+		}
+
+		RecomputeDownloadStatistics();
+
+		OnPropertyChanged(nameof(ToggleDownloadButtonText));
+		OnPropertyChanged(nameof(IsDownloading));
+		IsToggleDownloadButtonEnabled = true;
+	}
+
+	private void OnItemFinished(DownloadItem item) {
+		RecomputeDownloadStatistics();
+	}
+
+	public async Task OnClickRetryFailedDownloads() {
+		IsRetryingFailedDownloads = true;
+
+		try {
+			await state.Db.Downloads.RetryFailed();
+			RecomputeDownloadStatistics();
+		} catch (Exception e) {
+			Log.Error(e);
+		} finally {
+			IsRetryingFailedDownloads = false;
+		}
+	}
+
+	private void RecomputeDownloadStatistics() {
+		downloadStatisticsTask.Post(cancellationToken => state.Db.Downloads.GetStatistics(currentDownloadFilter ?? new DownloadItemFilter(), cancellationToken));
+	}
+
+	private void UpdateStatistics(DownloadStatusStatistics statusStatistics) {
+		statisticsPending.Items = statusStatistics.PendingCount;
+		statisticsPending.Size = statusStatistics.PendingTotalSize;
+		statisticsPending.HasFilesWithUnknownSize = statusStatistics.PendingWithUnknownSizeCount > 0;
+
+		statisticsDownloaded.Items = statusStatistics.SuccessfulCount;
+		statisticsDownloaded.Size = statusStatistics.SuccessfulTotalSize;
+		statisticsDownloaded.HasFilesWithUnknownSize = statusStatistics.SuccessfulWithUnknownSizeCount > 0;
+
+		statisticsFailed.Items = statusStatistics.FailedCount;
+		statisticsFailed.Size = statusStatistics.FailedTotalSize;
+		statisticsFailed.HasFilesWithUnknownSize = statusStatistics.FailedWithUnknownSizeCount > 0;
+		
+		statisticsSkipped.Items = statusStatistics.SkippedCount;
+		statisticsSkipped.Size = statusStatistics.SkippedTotalSize;
+		statisticsSkipped.HasFilesWithUnknownSize = statusStatistics.SkippedWithUnknownSizeCount > 0;
+
+		HasFailedDownloads = statusStatistics.FailedCount > 0;
+	}
+
+	[ObservableObject]
+	public sealed partial class StatisticsRow(string state) {
+		public string State { get; } = state;
+
+		[ObservableProperty]
+		private int items;
+
+		[ObservableProperty]
+		[NotifyPropertyChangedFor(nameof(SizeText))]
+		private ulong? size;
+		
+		[ObservableProperty]
+		[NotifyPropertyChangedFor(nameof(SizeText))]
+		private bool hasFilesWithUnknownSize;
+
+		public string SizeText {
+			get {
+				if (size == null) {
+					return "-";
+				}
+				else if (hasFilesWithUnknownSize) {
+					return "\u2265 " + BytesValueConverter.Convert(size.Value);
+				}
+				else {
+					return BytesValueConverter.Convert(size.Value);
+				}
+			}
+		}
+	}
+}

app/Desktop/Main/Pages/TrackingPage.axaml

@@ -4,7 +4,8 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:pages="clr-namespace:DHT.Desktop.Main.Pages"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
-             x:Class="DHT.Desktop.Main.Pages.TrackingPage">
+             x:Class="DHT.Desktop.Main.Pages.TrackingPage"
+             x:DataType="pages:TrackingPageModel">
 
     <Design.DataContext>
         <pages:TrackingPageModel />
@@ -15,7 +16,7 @@
             To start tracking messages, copy the tracking script and paste it into the console of either the Discord app, or your browser. The console is usually opened by pressing Ctrl+Shift+I.
         </TextBlock>
         <StackPanel DockPanel.Dock="Left" Orientation="Horizontal" Spacing="10">
-            <Button x:Name="CopyTrackingScript" Click="CopyTrackingScriptButton_OnClick">Copy Tracking Script</Button>
+            <Button x:Name="CopyTrackingScript" Click="CopyTrackingScriptButton_OnClick" IsEnabled="{Binding IsCopyTrackingScriptButtonEnabled}">Copy Tracking Script</Button>
         </StackPanel>
         <TextBlock TextWrapping="Wrap" Margin="0 5 0 0">
             By default, the Discord app does not allow opening the console. The button below will change a hidden setting in the Discord app that controls whether the Ctrl+Shift+I shortcut is enabled.

app/Desktop/Main/Pages/TrackingPageModel.cs

@@ -1,35 +1,39 @@
 using System;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Web;
 using Avalonia.Controls;
+using CommunityToolkit.Mvvm.ComponentModel;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Discord;
 using DHT.Desktop.Server;
-using DHT.Utils.Models;
 using static DHT.Desktop.Program;
 
 namespace DHT.Desktop.Main.Pages;
 
-sealed class TrackingPageModel : BaseModel {
+sealed partial class TrackingPageModel : ObservableObject {
-	private bool areDevToolsEnabled;
+	[ObservableProperty(Setter = Access.Private)]
+	private bool isCopyTrackingScriptButtonEnabled = true;
 
-	private bool AreDevToolsEnabled {
+	[ObservableProperty(Setter = Access.Private)]
-		get => areDevToolsEnabled;
+	[NotifyPropertyChangedFor(nameof(ToggleAppDevToolsButtonText))]
-		set {
+	private bool? areDevToolsEnabled = null;
-			Change(ref areDevToolsEnabled, value);
-			OnPropertyChanged(nameof(ToggleAppDevToolsButtonText));
-		}
-	}
 
-	public bool IsToggleAppDevToolsButtonEnabled { get; private set; } = true;
+	[ObservableProperty(Setter = Access.Private)]
+	[NotifyPropertyChangedFor(nameof(ToggleAppDevToolsButtonText))]
+	private bool isToggleAppDevToolsButtonEnabled = false;
 
 	public string ToggleAppDevToolsButtonText {
 		get {
+			if (!AreDevToolsEnabled.HasValue) {
+				return "Loading...";
+			}
+
 			if (!IsToggleAppDevToolsButtonEnabled) {
 				return "Unavailable";
 			}
 
-			return AreDevToolsEnabled ? "Disable Ctrl+Shift+I" : "Enable Ctrl+Shift+I";
+			return AreDevToolsEnabled.Value ? "Disable Ctrl+Shift+I" : "Enable Ctrl+Shift+I";
 		}
 	}
 
@@ -40,21 +44,22 @@ sealed class TrackingPageModel : BaseModel {
 
 	public TrackingPageModel(Window window) {
 		this.window = window;
+
+		Task.Factory.StartNew(InitializeDevToolsToggle, CancellationToken.None, TaskCreationOptions.None, TaskScheduler.FromCurrentSynchronizationContext());
 	}
 
-	public async Task Initialize() {
+	public async Task<bool> OnClickCopyTrackingScript() {
-		bool? devToolsEnabled = await DiscordAppSettings.AreDevToolsEnabled();
+		IsCopyTrackingScriptButtonEnabled = false;
-		if (devToolsEnabled.HasValue) {
+
-			AreDevToolsEnabled = devToolsEnabled.Value;
+		try {
-		}
+			return await CopyTrackingScript();
-		else {
+		} finally {
-			IsToggleAppDevToolsButtonEnabled = false;
+			IsCopyTrackingScriptButtonEnabled = true;
-			OnPropertyChanged(nameof(IsToggleAppDevToolsButtonEnabled));
 		}
 	}
-	
+
-	public async Task<bool> OnClickCopyTrackingScript() {
+	private async Task<bool> CopyTrackingScript() {
-		string url = $"http://127.0.0.1:{ServerManager.Port}/get-tracking-script?token={HttpUtility.UrlEncode(ServerManager.Token)}";
+		string url = $"http://127.0.0.1:{ServerConfiguration.Port}/get-tracking-script?token={HttpUtility.UrlEncode(ServerConfiguration.Token)}";
 		string script = (await Resources.ReadTextAsync("tracker-loader.js")).Trim().Replace("{url}", url);
 
 		var clipboard = window.Clipboard;
@@ -72,10 +77,26 @@ sealed class TrackingPageModel : BaseModel {
 		}
 	}
 
-	public async void OnClickToggleAppDevTools() {
+	private async Task InitializeDevToolsToggle() {
+		bool? devToolsEnabled = await Task.Run(DiscordAppSettings.AreDevToolsEnabled);
+
+		if (devToolsEnabled.HasValue) {
+			AreDevToolsEnabled = devToolsEnabled.Value;
+			IsToggleAppDevToolsButtonEnabled = true;
+		}
+		else {
+			IsToggleAppDevToolsButtonEnabled = false;
+		}
+	}
+
+	public async Task OnClickToggleAppDevTools() {
 		const string DialogTitle = "Discord App Settings File";
 
-		bool oldState = AreDevToolsEnabled;
+		if (!AreDevToolsEnabled.HasValue) {
+			return;
+		}
+
+		bool oldState = AreDevToolsEnabled.Value;
 		bool newState = !oldState;
 
 		switch (await DiscordAppSettings.ConfigureDevTools(newState)) {

app/Desktop/Main/Pages/ViewerPage.axaml

@@ -5,7 +5,8 @@
              xmlns:pages="clr-namespace:DHT.Desktop.Main.Pages"
              xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
-             x:Class="DHT.Desktop.Main.Pages.ViewerPage">
+             x:Class="DHT.Desktop.Main.Pages.ViewerPage"
+             x:DataType="pages:ViewerPageModel">
 
     <Design.DataContext>
         <pages:ViewerPageModel />

app/Desktop/Main/Pages/ViewerPageModel.cs

@@ -8,46 +8,46 @@ using System.Threading.Tasks;
 using System.Web;
 using Avalonia.Controls;
 using Avalonia.Platform.Storage;
+using CommunityToolkit.Mvvm.ComponentModel;
 using DHT.Desktop.Common;
 using DHT.Desktop.Dialogs.File;
 using DHT.Desktop.Dialogs.Message;
+using DHT.Desktop.Dialogs.Progress;
 using DHT.Desktop.Main.Controls;
 using DHT.Desktop.Server;
+using DHT.Server;
 using DHT.Server.Data.Filters;
-using DHT.Server.Database;
 using DHT.Server.Database.Export;
-using DHT.Server.Database.Export.Strategy;
-using DHT.Utils.Models;
 using static DHT.Desktop.Program;
 
 namespace DHT.Desktop.Main.Pages;
 
-sealed class ViewerPageModel : BaseModel, IDisposable {
+sealed partial class ViewerPageModel : ObservableObject, IDisposable {
-	public static readonly ConcurrentBag<string> TemporaryFiles = new ();
+	public static readonly ConcurrentBag<string> TemporaryFiles = [];
+
+	private static readonly FilePickerFileType[] ViewerFileTypes = [
+		FileDialogs.CreateFilter("Discord History Viewer", ["html"])
+	];
 
 	public bool DatabaseToolFilterModeKeep { get; set; } = true;
 	public bool DatabaseToolFilterModeRemove { get; set; } = false;
 
+	[ObservableProperty]
 	private bool hasFilters = false;
 
-	public bool HasFilters {
+	public MessageFilterPanelModel FilterModel { get; }
-		get => hasFilters;
-		set => Change(ref hasFilters, value);
-	}
-
-	private MessageFilterPanelModel FilterModel { get; }
 
 	private readonly Window window;
-	private readonly IDatabaseFile db;
+	private readonly State state;
 
 	[Obsolete("Designer")]
-	public ViewerPageModel() : this(null!, DummyDatabaseFile.Instance) {}
+	public ViewerPageModel() : this(null!, State.Dummy) {}
 
-	public ViewerPageModel(Window window, IDatabaseFile db) {
+	public ViewerPageModel(Window window, State state) {
 		this.window = window;
-		this.db = db;
+		this.state = state;
 
-		FilterModel = new MessageFilterPanelModel(window, db, "Will export");
+		FilterModel = new MessageFilterPanelModel(window, state, "Will export");
 		FilterModel.FilterPropertyChanged += OnFilterPropertyChanged;
 	}
 
@@ -59,11 +59,71 @@ sealed class ViewerPageModel : BaseModel, IDisposable {
 		HasFilters = FilterModel.HasAnyFilters;
 	}
 
-	private async Task WriteViewerFile(string path, IViewerExportStrategy strategy) {
+	public async void OnClickOpenViewer() {
+		try {
+			var fullPath = await PrepareTemporaryViewerFile();
+			
+			string jsConstants = $"""
+			                      window.DHT_SERVER_URL = "{HttpUtility.JavaScriptStringEncode("http://127.0.0.1:" + ServerConfiguration.Port)}";
+			                      window.DHT_SERVER_TOKEN = "{HttpUtility.JavaScriptStringEncode(ServerConfiguration.Token)}";
+			                      """;
+
+			await ProgressDialog.ShowIndeterminate(window, "Open Viewer", "Creating viewer...", _ => Task.Run(() => WriteViewerFile(fullPath, jsConstants)));
+			
+			Process.Start(new ProcessStartInfo(fullPath) {
+				UseShellExecute = true
+			});
+		} catch (Exception e) {
+			await Dialog.ShowOk(window, "Open Viewer", "Could not create or save viewer: " + e.Message);
+		}
+	}
+
+	private async Task<string> PrepareTemporaryViewerFile() {
+		return await Task.Run(() => {
+			string rootPath = Path.Combine(Path.GetTempPath(), "DiscordHistoryTracker");
+			string filenameBase = Path.GetFileNameWithoutExtension(state.Db.Path) + "-" + DateTime.Now.ToString("yyyy-MM-dd");
+			string fullPath = Path.Combine(rootPath, filenameBase + ".html");
+			
+			int counter = 0;
+
+			while (File.Exists(fullPath)) {
+				++counter;
+				fullPath = Path.Combine(rootPath, filenameBase + "-" + counter + ".html");
+			}
+
+			TemporaryFiles.Add(fullPath);
+
+			Directory.CreateDirectory(rootPath);
+
+			return fullPath;
+		});
+	}
+
+	public async void OnClickSaveViewer() {
+		string? path = await window.StorageProvider.SaveFile(new FilePickerSaveOptions {
+			Title = "Save Viewer",
+			FileTypeChoices = ViewerFileTypes,
+			SuggestedFileName = Path.GetFileNameWithoutExtension(state.Db.Path) + ".html",
+			SuggestedStartLocation = await FileDialogs.GetSuggestedStartLocation(window, Path.GetDirectoryName(state.Db.Path)),
+		});
+
+		if (path == null) {
+			return;
+		}
+
+		try {
+			await ProgressDialog.ShowIndeterminate(window, "Save Viewer", "Creating viewer...", _ => Task.Run(() => WriteViewerFile(path, string.Empty)));
+		} catch (Exception e) {
+			await Dialog.ShowOk(window, "Save Viewer", "Could not create or save viewer: " + e.Message);
+		}
+	}
+
+	private async Task WriteViewerFile(string path, string jsConstants) {
 		const string ArchiveTag = "/*[ARCHIVE]*/";
 
 		string indexFile = await Resources.ReadTextAsync("Viewer/index.html");
-		string viewerTemplate = indexFile.Replace("/*[JS]*/", await Resources.ReadJoinedAsync("Viewer/scripts/", '\n'))
+		string viewerTemplate = indexFile.Replace("/*[CONSTANTS]*/", jsConstants)
+		                                 .Replace("/*[JS]*/", await Resources.ReadJoinedAsync("Viewer/scripts/", '\n'))
 		                                 .Replace("/*[CSS]*/", await Resources.ReadJoinedAsync("Viewer/styles/", '\n'));
 
 		int viewerArchiveTagStart = viewerTemplate.IndexOf(ArchiveTag);
@@ -72,7 +132,7 @@ sealed class ViewerPageModel : BaseModel, IDisposable {
 		string jsonTempFile = path + ".tmp";
 
 		await using (var jsonStream = new FileStream(jsonTempFile, FileMode.Create, FileAccess.ReadWrite, FileShare.Read)) {
-			await ViewerJsonExport.Generate(jsonStream, strategy, db, FilterModel.CreateFilter());
+			await ViewerJsonExport.Generate(jsonStream, state.Db, FilterModel.CreateFilter());
 
 			char[] jsonBuffer = new char[Math.Min(32768, jsonStream.Position)];
 			jsonStream.Position = 0;
@@ -96,54 +156,23 @@ sealed class ViewerPageModel : BaseModel, IDisposable {
 		File.Delete(jsonTempFile);
 	}
 
-	public async void OnClickOpenViewer() {
+	public async Task OnClickApplyFiltersToDatabase() {
-		string rootPath = Path.Combine(Path.GetTempPath(), "DiscordHistoryTracker");
-		string filenameBase = Path.GetFileNameWithoutExtension(db.Path) + "-" + DateTime.Now.ToString("yyyy-MM-dd");
-		string fullPath = Path.Combine(rootPath, filenameBase + ".html");
-		int counter = 0;
-
-		while (File.Exists(fullPath)) {
-			++counter;
-			fullPath = Path.Combine(rootPath, filenameBase + "-" + counter + ".html");
-		}
-
-		TemporaryFiles.Add(fullPath);
-
-		Directory.CreateDirectory(rootPath);
-		await WriteViewerFile(fullPath, new LiveViewerExportStrategy(ServerManager.Port, ServerManager.Token));
-
-		Process.Start(new ProcessStartInfo(fullPath) { UseShellExecute = true });
-	}
-
-	private static readonly FilePickerFileType[] ViewerFileTypes = {
-		FileDialogs.CreateFilter("Discord History Viewer", new string[] { "html" }),
-	};
-	
-	public async void OnClickSaveViewer() {
-		string? path = await window.StorageProvider.SaveFile(new FilePickerSaveOptions {
-			Title = "Save Viewer",
-			FileTypeChoices = ViewerFileTypes,
-			SuggestedFileName = Path.GetFileNameWithoutExtension(db.Path) + ".html",
-			SuggestedStartLocation = await FileDialogs.GetSuggestedStartLocation(window, Path.GetDirectoryName(db.Path)),
-		});
-
-		if (path != null) {
-			await WriteViewerFile(path, StandaloneViewerExportStrategy.Instance);
-		}
-	}
-
-	public async void OnClickApplyFiltersToDatabase() {
 		var filter = FilterModel.CreateFilter();
+		var messageCount = await ProgressDialog.ShowIndeterminate(window, "Apply Filters", "Counting matching messages...", _ => state.Db.Messages.Count(filter));
 
 		if (DatabaseToolFilterModeKeep) {
-			if (DialogResult.YesNo.Yes == await Dialog.ShowYesNo(window, "Keep Matching Messages in This Database", db.CountMessages(filter).Pluralize("message") + " will be kept, and the rest will be removed from this database. This action cannot be undone. Proceed?")) {
+			if (DialogResult.YesNo.Yes == await Dialog.ShowYesNo(window, "Keep Matching Messages in This Database", messageCount.Pluralize("message") + " will be kept, and the rest will be removed from this database. This action cannot be undone. Proceed?")) {
-				db.RemoveMessages(filter, FilterRemovalMode.KeepMatching);
+				await ApplyFilterToDatabase(filter, FilterRemovalMode.KeepMatching);
 			}
 		}
 		else if (DatabaseToolFilterModeRemove) {
-			if (DialogResult.YesNo.Yes == await Dialog.ShowYesNo(window, "Remove Matching Messages in This Database", db.CountMessages(filter).Pluralize("message") + " will be removed from this database. This action cannot be undone. Proceed?")) {
+			if (DialogResult.YesNo.Yes == await Dialog.ShowYesNo(window, "Remove Matching Messages in This Database", messageCount.Pluralize("message") + " will be removed from this database. This action cannot be undone. Proceed?")) {
-				db.RemoveMessages(filter, FilterRemovalMode.RemoveMatching);
+				await ApplyFilterToDatabase(filter, FilterRemovalMode.RemoveMatching);
 			}
 		}
 	}
+
+	private async Task ApplyFilterToDatabase(MessageFilter filter, FilterRemovalMode removalMode) {
+		await ProgressDialog.ShowIndeterminate(window, "Apply Filters", "Removing messages...", _ => state.Db.Messages.Remove(filter, removalMode));
+	}
 }

app/Desktop/Main/Screens/MainContentScreen.axaml

@@ -5,7 +5,8 @@
              xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              xmlns:screens="clr-namespace:DHT.Desktop.Main.Screens"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
-             x:Class="DHT.Desktop.Main.Screens.MainContentScreen">
+             x:Class="DHT.Desktop.Main.Screens.MainContentScreen"
+             x:DataType="screens:MainContentScreenModel">
 
     <Design.DataContext>
         <screens:MainContentScreenModel />
@@ -73,7 +74,7 @@
     <DockPanel>
         <Border Classes="statusBar" DockPanel.Dock="Bottom">
             <DockPanel>
-                <TextBlock Classes="invisibleTabItem" DockPanel.Dock="Left">Attachments</TextBlock>
+                <TextBlock Classes="invisibleTabItem" DockPanel.Dock="Left">Downloads</TextBlock>
                 <controls:StatusBar DataContext="{Binding StatusBarModel}" DockPanel.Dock="Right" />
             </DockPanel>
         </Border>
@@ -93,9 +94,9 @@
                     <ContentPresenter Content="{Binding TrackingPage}" Classes="page" />
                 </ScrollViewer>
             </TabItem>
-            <TabItem x:Name="TabAttachments" Header="Attachments" Grid.Row="2">
+            <TabItem x:Name="TabDownloads" Header="Downloads" Grid.Row="2">
                 <ScrollViewer>
-                    <ContentPresenter Content="{Binding AttachmentsPage}" Classes="page" />
+                    <ContentPresenter Content="{Binding DownloadsPage}" Classes="page" />
                 </ScrollViewer>
             </TabItem>
             <TabItem x:Name="TabViewer" Header="Viewer" Grid.Row="3">

app/Desktop/Main/Screens/MainContentScreenModel.cs

@@ -1,27 +1,20 @@
 using System;
-using System.Threading.Tasks;
 using Avalonia.Controls;
-using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Main.Controls;
 using DHT.Desktop.Main.Pages;
-using DHT.Desktop.Server;
+using DHT.Server;
-using DHT.Server.Database;
-using DHT.Server.Service;
-using DHT.Utils.Logging;
 
 namespace DHT.Desktop.Main.Screens;
 
 sealed class MainContentScreenModel : IDisposable {
-	private static readonly Log Log = Log.ForType<MainContentScreenModel>();
-
 	public DatabasePage DatabasePage { get; }
 	private DatabasePageModel DatabasePageModel { get; }
 
 	public TrackingPage TrackingPage { get; }
 	private TrackingPageModel TrackingPageModel { get; }
 
-	public AttachmentsPage AttachmentsPage { get; }
+	public DownloadsPage DownloadsPage { get; }
-	private AttachmentsPageModel AttachmentsPageModel { get; }
+	private DownloadsPageModel DownloadsPageModel { get; }
 
 	public ViewerPage ViewerPage { get; }
 	private ViewerPageModel ViewerPageModel { get; }
@@ -35,7 +28,7 @@ sealed class MainContentScreenModel : IDisposable {
 	public bool HasDebugPage => true;
 	private DebugPageModel DebugPageModel { get; }
 	#else
-		public bool HasDebugPage => false;
+	public bool HasDebugPage => false;
 	#endif
 
 	public StatusBarModel StatusBarModel { get; }
@@ -49,71 +42,39 @@ sealed class MainContentScreenModel : IDisposable {
 		}
 	}
 
-	private readonly Window window;
-	private readonly ServerManager serverManager;
-
 	[Obsolete("Designer")]
-	public MainContentScreenModel() : this(null!, DummyDatabaseFile.Instance) {}
+	public MainContentScreenModel() : this(null!, State.Dummy) {}
 
-	public MainContentScreenModel(Window window, IDatabaseFile db) {
+	public MainContentScreenModel(Window window, State state) {
-		this.window = window;
+		DatabasePageModel = new DatabasePageModel(window, state);
-		this.serverManager = new ServerManager(db);
-
-		ServerLauncher.ServerManagementExceptionCaught += ServerLauncherOnServerManagementExceptionCaught;
-
-		DatabasePageModel = new DatabasePageModel(window, db);
 		DatabasePage = new DatabasePage { DataContext = DatabasePageModel };
 
 		TrackingPageModel = new TrackingPageModel(window);
 		TrackingPage = new TrackingPage { DataContext = TrackingPageModel };
 
-		AttachmentsPageModel = new AttachmentsPageModel(db);
+		DownloadsPageModel = new DownloadsPageModel(state);
-		AttachmentsPage = new AttachmentsPage { DataContext = AttachmentsPageModel };
+		DownloadsPage = new DownloadsPage { DataContext = DownloadsPageModel };
 
-		ViewerPageModel = new ViewerPageModel(window, db);
+		ViewerPageModel = new ViewerPageModel(window, state);
 		ViewerPage = new ViewerPage { DataContext = ViewerPageModel };
 
-		AdvancedPageModel = new AdvancedPageModel(window, db, serverManager);
+		AdvancedPageModel = new AdvancedPageModel(window, state);
 		AdvancedPage = new AdvancedPage { DataContext = AdvancedPageModel };
 
 		#if DEBUG
-		DebugPageModel = new DebugPageModel(window, db);
+		DebugPageModel = new DebugPageModel(window, state);
 		DebugPage = new DebugPage { DataContext = DebugPageModel };
 		#else
-			DebugPage = null;
+		DebugPage = null;
 		#endif
 
-		StatusBarModel = new StatusBarModel(db.Statistics);
+		StatusBarModel = new StatusBarModel(state);
-
-		AdvancedPageModel.ServerConfigurationModel.ServerStatusChanged += OnServerStatusChanged;
-		DatabaseClosed += OnDatabaseClosed;
-
-		StatusBarModel.CurrentStatus = serverManager.IsRunning ? StatusBarModel.Status.Ready : StatusBarModel.Status.Stopped;
-	}
-
-	public async Task Initialize() {
-		await TrackingPageModel.Initialize();
-		AdvancedPageModel.Initialize();
-		serverManager.Launch();
 	}
 
 	public void Dispose() {
-		ServerLauncher.ServerManagementExceptionCaught -= ServerLauncherOnServerManagementExceptionCaught;
+		DownloadsPageModel.Dispose();
-		AttachmentsPageModel.Dispose();
 		ViewerPageModel.Dispose();
-		serverManager.Dispose();
+		AdvancedPageModel.Dispose();
-	}
+		StatusBarModel.Dispose();
-
-	private void OnServerStatusChanged(object? sender, StatusBarModel.Status e) {
-		StatusBarModel.CurrentStatus = e;
-	}
-
-	private void OnDatabaseClosed(object? sender, EventArgs e) {
-		serverManager.Stop();
-	}
-
-	private async void ServerLauncherOnServerManagementExceptionCaught(object? sender, Exception ex) {
-		Log.Error(ex);
-		await Dialog.ShowOk(window, "Internal Server Error", ex.Message);
 	}
 }

app/Desktop/Main/Screens/WelcomeScreen.axaml

@@ -4,7 +4,8 @@
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:screens="clr-namespace:DHT.Desktop.Main.Screens"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
-             x:Class="DHT.Desktop.Main.Screens.WelcomeScreen">
+             x:Class="DHT.Desktop.Main.Screens.WelcomeScreen"
+             x:DataType="screens:WelcomeScreenModel">
 
     <Design.DataContext>
         <screens:WelcomeScreenModel />
@@ -31,7 +32,7 @@
             <TextBlock Text="{Binding Version, StringFormat=Discord History Tracker v{0}}" FontSize="25" Margin="0 0 0 30" HorizontalAlignment="Center" />
 
             <StackPanel Orientation="Horizontal" HorizontalAlignment="Center">
-                <Button Command="{Binding OpenOrCreateDatabase}">Open or Create Database</Button>
+                <Button Command="{Binding OpenOrCreateDatabase}" IsEnabled="{Binding IsOpenOrCreateDatabaseButtonEnabled}">Open or Create Database</Button>
                 <Button Command="{Binding ShowAboutDialog}">About</Button>
                 <Button Command="{Binding Exit}">Exit</Button>
             </StackPanel>

app/Desktop/Main/Screens/WelcomeScreenModel.cs

@@ -1,20 +1,25 @@
 using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
 using Avalonia.Controls;
+using CommunityToolkit.Mvvm.ComponentModel;
 using DHT.Desktop.Common;
 using DHT.Desktop.Dialogs.Message;
+using DHT.Desktop.Dialogs.Progress;
 using DHT.Server.Database;
-using DHT.Utils.Models;
+using DHT.Server.Database.Sqlite.Schema;
 
 namespace DHT.Desktop.Main.Screens;
 
-sealed class WelcomeScreenModel : BaseModel, IDisposable {
+sealed partial class WelcomeScreenModel : ObservableObject {
 	public string Version => Program.Version;
-
+	
-	public IDatabaseFile? Db { get; private set; }
+	[ObservableProperty(Setter = Access.Private)]
-	public bool HasDatabase => Db != null;
+	private bool isOpenOrCreateDatabaseButtonEnabled = true;
-
+	
+	public event EventHandler<IDatabaseFile>? DatabaseSelected; 
+	
 	private readonly Window window;
 
 	private string? dbFilePath;
@@ -26,45 +31,89 @@ sealed class WelcomeScreenModel : BaseModel, IDisposable {
 		this.window = window;
 	}
 
-	public async void OpenOrCreateDatabase() {
+	public async Task OpenOrCreateDatabase() {
-		var path = await DatabaseGui.NewOpenOrCreateDatabaseFileDialog(window, Path.GetDirectoryName(dbFilePath));
+		IsOpenOrCreateDatabaseButtonEnabled = false;
-		if (path != null) {
+		try {
-			await OpenOrCreateDatabaseFromPath(path);
+			var path = await DatabaseGui.NewOpenOrCreateDatabaseFileDialog(window, Path.GetDirectoryName(dbFilePath));
+			if (path != null) {
+				await OpenOrCreateDatabaseFromPath(path);
+			}
+		} finally {
+			IsOpenOrCreateDatabaseButtonEnabled = true;
 		}
 	}
 
 	public async Task OpenOrCreateDatabaseFromPath(string path) {
-		if (Db != null) {
+		dbFilePath = path;
-			Db = null;
+		
+		var db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, window, new SchemaUpgradeCallbacks(window));
+		if (db != null) {
+			DatabaseSelected?.Invoke(this, db);
+		}
+	}
+
+	private sealed class SchemaUpgradeCallbacks : ISchemaUpgradeCallbacks {
+		private readonly Window window;
+		
+		public SchemaUpgradeCallbacks(Window window) {
+			this.window = window;
 		}
 
-		dbFilePath = path;
+		public async Task<bool> CanUpgrade() {
-		Db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, window, CheckCanUpgradeDatabase);
+			return DialogResult.YesNo.Yes == await DatabaseGui.ShowCanUpgradeDatabaseDialog(window);
+		}
 
-		OnPropertyChanged(nameof(Db));
+		public async Task Start(int versionSteps, Func<ISchemaUpgradeCallbacks.IProgressReporter, Task> doUpgrade) {
-		OnPropertyChanged(nameof(HasDatabase));
+			async Task StartUpgrade(IReadOnlyList<IProgressCallback> callbacks) {
+				var reporter = new ProgressReporter(versionSteps, callbacks);
+				await reporter.NextVersion();
+				await Task.Delay(TimeSpan.FromMilliseconds(800));
+				await doUpgrade(reporter);
+				await Task.Delay(TimeSpan.FromMilliseconds(600));
+			}
+			
+			await new ProgressDialog { DataContext = new ProgressDialogModel("Upgrading Database", StartUpgrade, progressItems: 3) }.ShowProgressDialog(window);
+		}
+
+		private sealed class ProgressReporter : ISchemaUpgradeCallbacks.IProgressReporter {
+			private readonly IReadOnlyList<IProgressCallback> callbacks;
+			
+			private readonly int versionSteps;
+			private int versionProgress = 0;
+			
+			public ProgressReporter(int versionSteps, IReadOnlyList<IProgressCallback> callbacks) {
+				this.callbacks = callbacks;
+				this.versionSteps = versionSteps;
+			}
+
+			public async Task NextVersion() {
+				await callbacks[0].Update("Upgrading schema version...", versionProgress++, versionSteps);
+				await HideChildren(0);
+			}
+
+			public async Task MainWork(string message, int finishedItems, int totalItems) {
+				await callbacks[1].Update(message, finishedItems, totalItems);
+				await HideChildren(1);
+			}
+
+			public async Task SubWork(string message, int finishedItems, int totalItems) {
+				await callbacks[2].Update(message, finishedItems, totalItems);
+				await HideChildren(2);
+			}
+
+			private async Task HideChildren(int parentIndex) {
+				for (int i = parentIndex + 1; i < callbacks.Count; i++) {
+					await callbacks[i].Hide();
+				}
+			}
+		}
 	}
 
-	private async Task<bool> CheckCanUpgradeDatabase() {
+	public async Task ShowAboutDialog() {
-		return DialogResult.YesNo.Yes == await DatabaseGui.ShowCanUpgradeDatabaseDialog(window);
+		await new AboutWindow { DataContext = new AboutWindowModel() }.ShowDialog(window);
-	}
-
-	public void CloseDatabase() {
-		Dispose();
-		OnPropertyChanged(nameof(Db));
-		OnPropertyChanged(nameof(HasDatabase));
-	}
-
-	public async void ShowAboutDialog() {
-		await new AboutWindow { DataContext = new AboutWindowModel() }.ShowDialog(this.window);
 	}
 
 	public void Exit() {
 		window.Close();
 	}
-
-	public void Dispose() {
-		Db?.Dispose();
-		Db = null;
-	}
 }

app/Desktop/Program.cs

@@ -1,6 +1,8 @@
-using System.Globalization;
+using System;
+using System.Globalization;
 using System.Reflection;
 using Avalonia;
+using DHT.Utils.Logging;
 using DHT.Utils.Resources;
 
 namespace DHT.Desktop;
@@ -9,6 +11,7 @@ static class Program {
 	public static string Version { get; }
 	public static CultureInfo Culture { get; }
 	public static ResourceLoader Resources { get; }
+	public static Arguments Arguments { get; }
 
 	static Program() {
 		var assembly = Assembly.GetExecutingAssembly();
@@ -25,10 +28,21 @@ static class Program {
 		CultureInfo.DefaultThreadCurrentUICulture = CultureInfo.InvariantCulture;
 
 		Resources = new ResourceLoader(assembly);
+		Arguments = new Arguments(Environment.GetCommandLineArgs());
 	}
 
 	public static void Main(string[] args) {
-		BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
+		if (Arguments.Console && OperatingSystem.IsWindows()) {
+			WindowsConsole.AllocConsole();
+		}
+
+		try {
+			BuildAvaloniaApp().StartWithClassicDesktopLifetime(args);
+		} finally {
+			if (Arguments.Console && OperatingSystem.IsWindows()) {
+				WindowsConsole.FreeConsole();
+			}
+		}
 	}
 
 	private static AppBuilder BuildAvaloniaApp() {

app/Desktop/Server/ServerConfiguration.cs

@@ -0,0 +1,8 @@
+using DHT.Server.Service;
+
+namespace DHT.Desktop.Server;
+
+static class ServerConfiguration {
+	public static ushort Port { get; set; } = ServerUtils.FindAvailablePort(50000, 60000);
+	public static string Token { get; set; } = ServerUtils.GenerateRandomToken(20);
+}

app/Desktop/Server/ServerManager.cs

@@ -1,50 +0,0 @@
-using System;
-using DHT.Server.Database;
-using DHT.Server.Service;
-
-namespace DHT.Desktop.Server;
-
-sealed class ServerManager : IDisposable {
-	public static ushort Port { get; set; } = ServerUtils.FindAvailablePort(50000, 60000);
-	public static string Token { get; set; } = ServerUtils.GenerateRandomToken(20);
-
-	private static ServerManager? instance;
-
-	public bool IsRunning => ServerLauncher.IsRunning;
-
-	private readonly IDatabaseFile db;
-
-	public ServerManager(IDatabaseFile db) {
-		if (db != DummyDatabaseFile.Instance) {
-			if (instance != null) {
-				throw new InvalidOperationException("Only one instance of ServerManager can exist at the same time!");
-			}
-
-			instance = this;
-		}
-
-		this.db = db;
-	}
-
-	public void Launch() {
-		ServerLauncher.Relaunch(Port, Token, db);
-	}
-
-	public void Relaunch(ushort port, string token) {
-		Port = port;
-		Token = token;
-		Launch();
-	}
-
-	public void Stop() {
-		ServerLauncher.Stop();
-	}
-
-	public void Dispose() {
-		Stop();
-
-		if (instance == this) {
-			instance = null;
-		}
-	}
-}

app/Directory.Build.props

@@ -2,7 +2,7 @@
   
   <PropertyGroup>
     <TargetFramework>net8.0</TargetFramework>
-    <LangVersion>11</LangVersion>
+    <LangVersion>12</LangVersion>
     <Nullable>enable</Nullable>
   </PropertyGroup>
   
@@ -19,9 +19,21 @@
   </PropertyGroup>
   
   <PropertyGroup>
+    <SuppressTrimAnalysisWarnings>false</SuppressTrimAnalysisWarnings>
     <PublishTrimmed>true</PublishTrimmed>
     <TrimMode>partial</TrimMode>
-    <JsonSerializerIsReflectionEnabledByDefault>true</JsonSerializerIsReflectionEnabledByDefault>
+    <EnableUnsafeBinaryFormatterSerialization>false</EnableUnsafeBinaryFormatterSerialization>
+    <EnableUnsafeUTF7Encoding>false</EnableUnsafeUTF7Encoding>
+    <EventSourceSupport>false</EventSourceSupport>
+    <HttpActivityPropagationSupport>false</HttpActivityPropagationSupport>
+    <JsonSerializerIsReflectionEnabledByDefault>false</JsonSerializerIsReflectionEnabledByDefault>
+  </PropertyGroup>
+  
+  <PropertyGroup>
+    <PublishSingleFile>true</PublishSingleFile>
+    <PublishReadyToRun>false</PublishReadyToRun>
+    <EnableCompressionInSingleFile>true</EnableCompressionInSingleFile>
+    <IncludeNativeLibrariesForSelfExtract>true</IncludeNativeLibrariesForSelfExtract>
   </PropertyGroup>
   
   <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">

app/NuGet.Config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<configuration>
+  <packageSources>
+    <add key="chylex's repository" value="https://nuget.chylex.com/feed/index.json" />
+  </packageSources>
+</configuration>

app/Resources/Tracker/scripts/state.js

@@ -48,6 +48,16 @@ const STATE = (function() {
 		});
 	};
 	
+	const getDate = function(date) {
+		if (date instanceof Date) {
+			return date;
+		}
+		else {
+			// noinspection JSUnresolvedReference
+			return date.toDate();
+		}
+	};
+	
 	const trackingStateChangedListeners = [];
 	let isTracking = false;
 	
@@ -69,8 +79,8 @@ const STATE = (function() {
 	 * @property {String} channel_id
 	 * @property {DiscordUser} author
 	 * @property {String} content
-	 * @property {Timestamp} timestamp
+	 * @property {Date} timestamp
-	 * @property {Timestamp|null} editedTimestamp
+	 * @property {Date|null} editedTimestamp
 	 * @property {DiscordAttachment[]} attachments
 	 * @property {Object[]} embeds
 	 * @property {DiscordMessageReaction[]} [reactions]
@@ -106,11 +116,6 @@ const STATE = (function() {
 	 * @property {Boolean} animated
 	 */
 	
-	/**
-	 * @name Timestamp
-	 * @property {Function} toDate
-	 */
-	
 	return {
 		setup(port, token) {
 			serverPort = port;
@@ -223,12 +228,12 @@ const STATE = (function() {
 					sender: msg.author.id,
 					channel: msg.channel_id,
 					text: msg.content,
-					timestamp: msg.timestamp.toDate().getTime()
+					timestamp: getDate(msg.timestamp).getTime()
 				};
 				
 				if (msg.editedTimestamp !== null) {
 					// noinspection JSUnusedGlobalSymbols
-					obj.editTimestamp = msg.editedTimestamp.toDate().getTime();
+					obj.editTimestamp = getDate(msg.editedTimestamp).getTime();
 				}
 				
 				if (msg.messageReference !== null) {

app/Resources/Viewer/index.html

@@ -6,6 +6,7 @@
     
     <script type="text/javascript">
 		window.DHT_EMBEDDED = "/*[ARCHIVE]*/";
+		/*[CONSTANTS]*/
 		/*[JS]*/
     </script>
     <style>

app/Resources/Viewer/scripts/discord.js

@@ -35,6 +35,23 @@ const DISCORD = (function() {
 	let templateReaction;
 	let templateReactionCustom;
 	
+	const fileUrlProcessor = function(serverUrl, serverToken) {
+		if (typeof serverUrl === "string" && typeof serverToken === "string") {
+			return url => serverUrl + "/get-downloaded-file/" + encodeURIComponent(url) + "?token=" + encodeURIComponent(serverToken);
+		}
+		else {
+			return url => url;
+		}
+	}(
+		window["DHT_SERVER_URL"],
+		window["DHT_SERVER_TOKEN"]
+	);
+	
+	const getEmoji = function(name, id, extension) {
+		const tag = ":" + name + ":";
+		return "<img src='" + fileUrlProcessor("https://cdn.discordapp.com/emojis/" + id + "." + extension) + "' alt='" + tag + "' title='" + tag + "' class='emoji'>";
+	};
+	
 	const processMessageContents = function(contents) {
 		let processed = DOM.escapeHTML(contents.replace(regex.formatUrlNoEmbed, "$1"));
 		
@@ -54,29 +71,33 @@ const DISCORD = (function() {
 				.replace(regex.formatStrike, "<s>$1</s>");
 		}
 		
-		const animatedEmojiExtension = SETTINGS.enableAnimatedEmoji ? "gif" : "png";
+		const animatedEmojiExtension = SETTINGS.enableAnimatedEmoji ? "gif" : "webp";
 		
 		// noinspection HtmlUnknownTarget
 		processed = processed
 			.replace(regex.formatUrl, "<a href='$1' target='_blank' rel='noreferrer'>$1</a>")
 			.replace(regex.mentionChannel, (full, match) => "<span class='link mention-chat'>#" + STATE.getChannelName(match) + "</span>")
 			.replace(regex.mentionUser, (full, match) => "<span class='link mention-user' title='#" + (STATE.getUserTag(match) || "????") + "'>@" + STATE.getUserName(match) + "</span>")
-			.replace(regex.customEmojiStatic, "<img src='https://cdn.discordapp.com/emojis/$2.png' alt=':$1:' title=':$1:' class='emoji'>")
+			.replace(regex.customEmojiStatic, (full, m1, m2) => getEmoji(m1, m2, "webp"))
-			.replace(regex.customEmojiAnimated, "<img src='https://cdn.discordapp.com/emojis/$2." + animatedEmojiExtension + "' alt=':$1:' title=':$1:' class='emoji'>");
+			.replace(regex.customEmojiAnimated, (full, m1, m2) => getEmoji(m1, m2, animatedEmojiExtension));
 		
 		return "<p>" + processed + "</p>";
 	};
 	
+	const getAvatarUrlObject = function(avatar) {
+		return { url: fileUrlProcessor("https://cdn.discordapp.com/avatars/" + avatar.id + "/" + avatar.path + ".webp") };
+	};
+	
 	const getImageEmbed = function(url, image) {
 		if (!SETTINGS.enableImagePreviews) {
 			return "";
 		}
 		
 		if (image.width && image.height) {
-			return templateEmbedImageWithSize.apply({ url, src: image.url, width: image.width, height: image.height });
+			return templateEmbedImageWithSize.apply({ url: fileUrlProcessor(url), src: fileUrlProcessor(image.url), width: image.width, height: image.height });
 		}
 		else {
-			return templateEmbedImage.apply({ url, src: image.url });
+			return templateEmbedImage.apply({ url: fileUrlProcessor(url), src: fileUrlProcessor(image.url) });
 		}
 	};
 	
@@ -125,8 +146,9 @@ const DISCORD = (function() {
 				"</div>"
 			].join(""));
 			
+			// noinspection HtmlUnknownTarget
 			templateUserAvatar = new TEMPLATE([
-				"<img src='https://cdn.discordapp.com/avatars/{id}/{path}.webp?size=128' alt=''>"
+				"<img src='{url}' alt=''>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
@@ -167,8 +189,9 @@ const DISCORD = (function() {
 				"<span class='reaction-wrapper'><span class='reaction-emoji'>{n}</span><span class='count'>{c}</span></span>"
 			].join(""));
 			
+			// noinspection HtmlUnknownTarget
 			templateReactionCustom = new TEMPLATE([
-				"<span class='reaction-wrapper'><img src='https://cdn.discordapp.com/emojis/{id}.{ext}' alt=':{n}:' title=':{n}:' class='reaction-emoji-custom'><span class='count'>{c}</span></span>"
+				"<span class='reaction-wrapper'><img src='{url}' alt=':{n}:' title=':{n}:' class='reaction-emoji-custom'><span class='count'>{c}</span></span>"
 			].join(""));
 		},
 		
@@ -199,7 +222,7 @@ const DISCORD = (function() {
 		getMessageHTML(message) { // noinspection FunctionWithInconsistentReturnsJS
 			return (SETTINGS.enableUserAvatars ? templateMessageWithAvatar : templateMessageNoAvatar).apply(message, (property, value) => {
 				if (property === "avatar") {
-					return value ? templateUserAvatar.apply(value) : "";
+					return value ? templateUserAvatar.apply(getAvatarUrlObject(value)) : "";
 				}
 				else if (property === "user.tag") {
 					return value ? value : "????";
@@ -220,10 +243,10 @@ const DISCORD = (function() {
 							return templateEmbedUnsupported.apply(embed);
 						}
 						else if ("image" in embed && embed.image.url) {
-							return getImageEmbed(embed.url, embed.image);
+							return getImageEmbed(fileUrlProcessor(embed.url), embed.image);
 						}
 						else if ("thumbnail" in embed && embed.thumbnail.url) {
-							return getImageEmbed(embed.url, embed.thumbnail);
+							return getImageEmbed(fileUrlProcessor(embed.url), embed.thumbnail);
 						}
 						else if ("title" in embed && "description" in embed) {
 							return templateEmbedRich.apply(embed);
@@ -242,14 +265,16 @@ const DISCORD = (function() {
 					}
 					
 					return value.map(attachment => {
+						const url = fileUrlProcessor(attachment.url);
+						
 						if (!DISCORD.isImageAttachment(attachment) || !SETTINGS.enableImagePreviews) {
-							return templateAttachmentDownload.apply(attachment);
+							return templateAttachmentDownload.apply({ url, name: attachment.name });
 						}
 						else if ("width" in attachment && "height" in attachment) {
-							return templateEmbedImageWithSize.apply({ url: attachment.url, src: attachment.url, width: attachment.width, height: attachment.height });
+							return templateEmbedImageWithSize.apply({ url, src: url, width: attachment.width, height: attachment.height });
 						}
 						else {
-							return templateEmbedImage.apply({ url: attachment.url, src: attachment.url });
+							return templateEmbedImage.apply({ url, src: url });
 						}
 					}).join("");
 				}
@@ -265,7 +290,7 @@ const DISCORD = (function() {
 					}
 					
 					const user = "<span class='reply-username' title='#" + (value.user.tag ? value.user.tag : "????") + "'>" + value.user.name + "</span>";
-					const avatar = SETTINGS.enableUserAvatars && value.avatar ? "<span class='reply-avatar'>" + templateUserAvatar.apply(value.avatar) + "</span>" : "";
+					const avatar = SETTINGS.enableUserAvatars && value.avatar ? "<span class='reply-avatar'>" + templateUserAvatar.apply(getAvatarUrlObject(value.avatar)) + "</span>" : "";
 					const contents = value.contents ? "<span class='reply-contents'>" + processMessageContents(value.contents) + "</span>" : "";
 					
 					return "<span class='jump' data-jump='" + value.id + "'>Jump to reply</span><span class='user'>" + avatar + user + "</span>" + contents;
@@ -277,9 +302,10 @@ const DISCORD = (function() {
 					
 					return "<div class='reactions'>" + value.map(reaction => {
 						if ("id" in reaction){
-							// noinspection JSUnusedGlobalSymbols, JSUnresolvedVariable
+							const ext = reaction.a && SETTINGS.enableAnimatedEmoji ? "gif" : "webp";
-							reaction.ext = reaction.a && SETTINGS.enableAnimatedEmoji ? "gif" : "png";
+							const url = fileUrlProcessor("https://cdn.discordapp.com/emojis/" + reaction.id + "." + ext);
-							return templateReactionCustom.apply(reaction);
+							// noinspection JSUnusedGlobalSymbols
+							return templateReactionCustom.apply({ url, n: reaction.n, c: reaction.c });
 						}
 						else {
 							return templateReaction.apply(reaction);

app/Server/Data/Aggregations/DownloadStatusStatistics.cs

@@ -1,15 +1,19 @@
 namespace DHT.Server.Data.Aggregations;
 
 public sealed class DownloadStatusStatistics {
-	public int EnqueuedCount { get; internal set; }
+	public int PendingCount { get; internal init; }
-	public ulong EnqueuedSize { get; internal set; }
+	public ulong PendingTotalSize { get; internal init; }
+	public int PendingWithUnknownSizeCount { get; internal init; }
 
-	public int SuccessfulCount { get; internal set; }
+	public int SuccessfulCount { get; internal init; }
-	public ulong SuccessfulSize { get; internal set; }
+	public ulong SuccessfulTotalSize { get; internal init; }
+	public int SuccessfulWithUnknownSizeCount { get; internal init; }
 
-	public int FailedCount { get; internal set; }
+	public int FailedCount { get; internal init; }
-	public ulong FailedSize { get; internal set; }
+	public ulong FailedTotalSize { get; internal init; }
-
+	public int FailedWithUnknownSizeCount { get; internal init; }
-	public int SkippedCount { get; internal set; }
+	
-	public ulong SkippedSize { get; internal set; }
+	public int SkippedCount { get; internal init; }
+	public ulong SkippedTotalSize { get; internal init; }
+	public int SkippedWithUnknownSizeCount { get; internal init; }
 }

app/Server/Data/Download.cs

@@ -1,33 +1,17 @@
-using System;
-using System.Net;
-using DHT.Server.Download;
-
 namespace DHT.Server.Data;
 
-public readonly struct Download {
+public sealed class Download {
-	internal static Download NewSuccess(DownloadItem item, byte[] data) {
-		return new Download(item.NormalizedUrl, item.DownloadUrl, DownloadStatus.Success, (ulong) Math.Max(data.LongLength, 0), data);
-	}
-
-	internal static Download NewFailure(DownloadItem item, HttpStatusCode? statusCode, ulong size) {
-		return new Download(item.NormalizedUrl, item.DownloadUrl, statusCode.HasValue ? (DownloadStatus) (int) statusCode : DownloadStatus.GenericError, size);
-	}
-
 	public string NormalizedUrl { get; }
 	public string DownloadUrl { get; }
 	public DownloadStatus Status { get; }
-	public ulong Size { get; }
+	public string? Type { get; }
-	public byte[]? Data { get; }
+	public ulong? Size { get; }
 
-	internal Download(string normalizedUrl, string downloadUrl, DownloadStatus status, ulong size, byte[]? data = null) {
+	internal Download(string normalizedUrl, string downloadUrl, DownloadStatus status, string? type, ulong? size) {
 		NormalizedUrl = normalizedUrl;
 		DownloadUrl = downloadUrl;
 		Status = status;
+		Type = type;
 		Size = size;
-		Data = data;
-	}
-
-	internal Download WithData(byte[] data) {
-		return new Download(NormalizedUrl, DownloadUrl, Status, Size, data);
 	}
 }

app/Server/Data/DownloadStatus.cs

@@ -6,7 +6,9 @@ namespace DHT.Server.Data;
 /// Extends <see cref="HttpStatusCode"/> with custom status codes in the range 0-99.
 /// </summary>
 public enum DownloadStatus {
-	Enqueued = 0,
+	Pending = 0,
 	GenericError = 1,
+	Downloading = 2,
+	LastCustomCode = 99,
 	Success = HttpStatusCode.OK
 }

app/Server/Data/DownloadedAttachment.cs

@@ -1,6 +0,0 @@
-namespace DHT.Server.Data;
-
-public readonly struct DownloadedAttachment {
-	public string? Type { get; internal init; }
-	public byte[] Data { get; internal init; }
-}

app/Server/Data/Embeds/DiscordEmbedJson.cs

@@ -0,0 +1,17 @@
+namespace DHT.Server.Data.Embeds;
+
+sealed class DiscordEmbedJson {
+	public string? Type { get; set; }
+	public string? Url { get; set; }
+	
+	public JsonImage? Image { get; set; }
+	public JsonImage? Thumbnail { get; set; }
+	public JsonImage? Video { get; set; }
+
+	public sealed class JsonImage {
+		public string? Url { get; set; }
+		public string? ProxyUrl { get; set; }
+		public int? Width { get; set; }
+		public int? Height { get; set; }
+	}
+}

app/Server/Data/Embeds/DiscordEmbedJsonContext.cs

@@ -0,0 +1,7 @@
+using System.Text.Json.Serialization;
+
+namespace DHT.Server.Data.Embeds;
+
+[JsonSourceGenerationOptions(PropertyNamingPolicy = JsonKnownNamingPolicy.SnakeCaseLower, GenerationMode = JsonSourceGenerationMode.Default)]
+[JsonSerializable(typeof(DiscordEmbedJson))]
+sealed partial class DiscordEmbedJsonContext : JsonSerializerContext;

app/Server/Data/Filters/AttachmentFilter.cs

@@ -1,15 +0,0 @@
-namespace DHT.Server.Data.Filters;
-
-public sealed class AttachmentFilter {
-	public ulong? MaxBytes { get; set; } = null;
-
-	public DownloadItemRules? DownloadItemRule { get; set; } = null;
-
-	public bool IsEmpty => MaxBytes == null &&
-	                       DownloadItemRule == null;
-
-	public enum DownloadItemRules {
-		OnlyNotPresent,
-		OnlyPresent
-	}
-}

app/Server/Data/Filters/DownloadItemFilter.cs

@@ -3,8 +3,10 @@ using System.Collections.Generic;
 namespace DHT.Server.Data.Filters;
 
 public sealed class DownloadItemFilter {
-	public HashSet<DownloadStatus>? IncludeStatuses { get; init; } = null;
+	public HashSet<DownloadStatus>? IncludeStatuses { get; set; } = null;
-	public HashSet<DownloadStatus>? ExcludeStatuses { get; init; } = null;
+	public HashSet<DownloadStatus>? ExcludeStatuses { get; set; } = null;
+	
+	public ulong? MaxBytes { get; set; } = null;
 
-	public bool IsEmpty => IncludeStatuses == null && ExcludeStatuses == null;
+	public bool IsEmpty => IncludeStatuses == null && ExcludeStatuses == null && MaxBytes == null;
 }

app/Server/Data/Message.cs

@@ -10,7 +10,7 @@ public readonly struct Message {
 	public long Timestamp { get; init; }
 	public long? EditTimestamp { get; init; }
 	public ulong? RepliedToId { get; init; }
-	public ImmutableArray<Attachment> Attachments { get; init; }
+	public ImmutableList<Attachment> Attachments { get; init; }
-	public ImmutableArray<Embed> Embeds { get; init; }
+	public ImmutableList<Embed> Embeds { get; init; }
-	public ImmutableArray<Reaction> Reactions { get; init; }
+	public ImmutableList<Reaction> Reactions { get; init; }
 }

app/Server/Database/DatabaseExtensions.cs

@@ -1,29 +1,34 @@
 using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
 using DHT.Server.Data;
 
 namespace DHT.Server.Database;
 
 public static class DatabaseExtensions {
-	public static void AddFrom(this IDatabaseFile target, IDatabaseFile source) {
+	public static async Task AddFrom(this IDatabaseFile target, IDatabaseFile source) {
-		target.AddServers(source.GetAllServers());
+		await target.Users.Add(await source.Users.Get().ToListAsync());
-		target.AddChannels(source.GetAllChannels());
+		await target.Servers.Add(await source.Servers.Get().ToListAsync());
-		target.AddUsers(source.GetAllUsers().ToArray());
+		await target.Channels.Add(await source.Channels.Get().ToListAsync());
-		target.AddMessages(source.GetMessages().ToArray());
 
-		foreach (var download in source.GetDownloadsWithoutData()) {
+		const int MessageBatchSize = 100;
-			target.AddDownload(download.Status == DownloadStatus.Success ? source.GetDownloadWithData(download) : download);
+		List<Message> batchedMessages = new (MessageBatchSize);
+		
+		await foreach (var message in source.Messages.Get()) {
+			batchedMessages.Add(message);
+
+			if (batchedMessages.Count >= MessageBatchSize) {
+				await target.Messages.Add(batchedMessages);
+				batchedMessages.Clear();
+			}
 		}
-	}
+		
+		await target.Messages.Add(batchedMessages);
 
-	internal static void AddServers(this IDatabaseFile target, IEnumerable<Data.Server> servers) {
+		await foreach (var download in source.Downloads.Get()) {
-		foreach (var server in servers) {
+			if (download.Status != DownloadStatus.Success || !await source.Downloads.GetDownloadData(download.NormalizedUrl, stream => target.Downloads.AddDownload(download, stream))) {
-			target.AddServer(server);
+				await target.Downloads.AddDownload(download, stream: null);
-		}
+			}
-	}
-
-	internal static void AddChannels(this IDatabaseFile target, IEnumerable<Channel> channels) {
-		foreach (var channel in channels) {
-			target.AddChannel(channel);
 		}
 	}
 }

app/Server/Database/DatabaseStatistics.cs

@@ -1,46 +0,0 @@
-using DHT.Utils.Models;
-
-namespace DHT.Server.Database;
-
-/// <summary>
-/// A live view of database statistics.
-/// Some of the totals are computed asynchronously and may not reflect the most recent version of the database, or may not be available at all until computed for the first time.
-/// </summary>
-public sealed class DatabaseStatistics : BaseModel {
-	private long totalServers;
-	private long totalChannels;
-	private long totalUsers;
-	private long? totalMessages;
-	private long? totalAttachments;
-	private long? totalDownloads;
-
-	public long TotalServers {
-		get => totalServers;
-		internal set => Change(ref totalServers, value);
-	}
-
-	public long TotalChannels {
-		get => totalChannels;
-		internal set => Change(ref totalChannels, value);
-	}
-
-	public long TotalUsers {
-		get => totalUsers;
-		internal set => Change(ref totalUsers, value);
-	}
-
-	public long? TotalMessages {
-		get => totalMessages;
-		internal set => Change(ref totalMessages, value);
-	}
-
-	public long? TotalAttachments {
-		get => totalAttachments;
-		internal set => Change(ref totalAttachments, value);
-	}
-
-	public long? TotalDownloads {
-		get => totalDownloads;
-		internal set => Change(ref totalDownloads, value);
-	}
-}

app/Server/Database/DatabaseStatisticsSnapshot.cs

@@ -1,11 +0,0 @@
-namespace DHT.Server.Database;
-
-/// <summary>
-/// A complete snapshot of database statistics at a particular point in time.
-/// </summary>
-public readonly struct DatabaseStatisticsSnapshot {
-	public long TotalServers { get; internal init; }
-	public long TotalChannels { get; internal init; }
-	public long TotalUsers { get; internal init; }
-	public long TotalMessages { get; internal init; }
-}

app/Server/Database/DummyDatabaseFile.cs

@@ -1,90 +1,28 @@
-using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using DHT.Server.Data;
+using System.Threading.Tasks;
-using DHT.Server.Data.Aggregations;
+using DHT.Server.Database.Repositories;
-using DHT.Server.Data.Filters;
-using DHT.Server.Download;
 
 namespace DHT.Server.Database;
 
 [SuppressMessage("ReSharper", "ArrangeObjectCreationWhenTypeNotEvident")]
-public sealed class DummyDatabaseFile : IDatabaseFile {
+sealed class DummyDatabaseFile : IDatabaseFile {
-	public static DummyDatabaseFile Instance { get; } = new();
+	public static DummyDatabaseFile Instance { get; } = new ();
 
 	public string Path => "";
-	public DatabaseStatistics Statistics { get; } = new();
+	
-
+	public IUserRepository Users { get; } = new IUserRepository.Dummy();
+	public IServerRepository Servers { get; } = new IServerRepository.Dummy();
+	public IChannelRepository Channels { get; } = new IChannelRepository.Dummy();
+	public IMessageRepository Messages { get; } = new IMessageRepository.Dummy();
+	public IDownloadRepository Downloads { get; } = new IDownloadRepository.Dummy();
+	
 	private DummyDatabaseFile() {}
 
-	public DatabaseStatisticsSnapshot SnapshotStatistics() {
+	public Task Vacuum() {
-		return new();
+		return Task.CompletedTask;
 	}
 
-	public void AddServer(Data.Server server) {}
+	public ValueTask DisposeAsync() {
-
+		return ValueTask.CompletedTask;
-	public List<Data.Server> GetAllServers() {
-		return new();
 	}
-
-	public void AddChannel(Channel channel) {}
-
-	public List<Channel> GetAllChannels() {
-		return new();
-	}
-
-	public void AddUsers(User[] users) {}
-
-	public List<User> GetAllUsers() {
-		return new();
-	}
-
-	public void AddMessages(Message[] messages) {}
-
-	public int CountMessages(MessageFilter? filter = null) {
-		return 0;
-	}
-
-	public List<Message> GetMessages(MessageFilter? filter = null) {
-		return new();
-	}
-
-	public HashSet<ulong> GetMessageIds(MessageFilter? filter = null) {
-		return new();
-	}
-
-	public void RemoveMessages(MessageFilter filter, FilterRemovalMode mode) {}
-
-	public int CountAttachments(AttachmentFilter? filter = null) {
-		return new();
-	}
-
-	public List<Data.Download> GetDownloadsWithoutData() {
-		return new();
-	}
-
-	public Data.Download GetDownloadWithData(Data.Download download) {
-		return download;
-	}
-
-	public DownloadedAttachment? GetDownloadedAttachment(string url) {
-		return null;
-	}
-
-	public void AddDownload(Data.Download download) {}
-
-	public void EnqueueDownloadItems(AttachmentFilter? filter = null) {}
-
-	public List<DownloadItem> GetEnqueuedDownloadItems(int count) {
-		return new();
-	}
-
-	public void RemoveDownloadItems(DownloadItemFilter? filter, FilterRemovalMode mode) {}
-
-	public DownloadStatusStatistics GetDownloadStatusStatistics() {
-		return new();
-	}
-
-	public void Vacuum() {}
-
-	public void Dispose() {}
 }

app/Server/Database/Exceptions/DatabaseTooNewException.cs

@@ -5,9 +5,9 @@ namespace DHT.Server.Database.Exceptions;
 
 public sealed class DatabaseTooNewException : Exception {
 	public int DatabaseVersion { get; }
-	public int CurrentVersion => Schema.Version;
+	public int CurrentVersion => SqliteSchema.Version;
 
-	internal DatabaseTooNewException(int databaseVersion) : base("Database is too new: " + databaseVersion + " > " + Schema.Version) {
+	internal DatabaseTooNewException(int databaseVersion) : base("Database is too new: " + databaseVersion + " > " + SqliteSchema.Version) {
 		this.DatabaseVersion = databaseVersion;
 	}
 }

app/Server/Database/Export/Snowflake.cs

@@ -0,0 +1,3 @@
+namespace DHT.Server.Database.Export;
+
+readonly record struct Snowflake(ulong Id);

app/Server/Database/Export/SnowflakeJsonSerializer.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace DHT.Server.Database.Export;
+
+sealed class SnowflakeJsonSerializer : JsonConverter<Snowflake> {
+	public override Snowflake Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
+		return new Snowflake(ulong.Parse(reader.GetString()!));
+	}
+
+	public override void Write(Utf8JsonWriter writer, Snowflake value, JsonSerializerOptions options) {
+		writer.WriteStringValue(value.Id.ToString());
+	}
+
+	public override Snowflake ReadAsPropertyName(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
+		return new Snowflake(ulong.Parse(reader.GetString()!));
+	}
+
+	public override void WriteAsPropertyName(Utf8JsonWriter writer, Snowflake value, JsonSerializerOptions options) {
+		writer.WritePropertyName(value.Id.ToString());
+	}
+}

app/Server/Database/Export/Strategy/IViewerExportStrategy.cs

@@ -1,7 +0,0 @@
-using DHT.Server.Data;
-
-namespace DHT.Server.Database.Export.Strategy;
-
-public interface IViewerExportStrategy {
-	string GetAttachmentUrl(Attachment attachment);
-}

app/Server/Database/Export/Strategy/LiveViewerExportStrategy.cs

@@ -1,18 +0,0 @@
-using System.Net;
-using DHT.Server.Data;
-
-namespace DHT.Server.Database.Export.Strategy;
-
-public sealed class LiveViewerExportStrategy : IViewerExportStrategy {
-	private readonly string safePort;
-	private readonly string safeToken;
-
-	public LiveViewerExportStrategy(ushort port, string token) {
-		this.safePort = port.ToString();
-		this.safeToken = WebUtility.UrlEncode(token);
-	}
-
-	public string GetAttachmentUrl(Attachment attachment) {
-		return "http://127.0.0.1:" + safePort + "/get-attachment/" + WebUtility.UrlEncode(attachment.NormalizedUrl) + "?token=" + safeToken;
-	}
-}

app/Server/Database/Export/Strategy/StandaloneViewerExportStrategy.cs

@@ -1,18 +0,0 @@
-using DHT.Server.Data;
-
-namespace DHT.Server.Database.Export.Strategy;
-
-public sealed class StandaloneViewerExportStrategy : IViewerExportStrategy {
-	public static StandaloneViewerExportStrategy Instance { get; } = new ();
-
-	private StandaloneViewerExportStrategy() {}
-
-	public string GetAttachmentUrl(Attachment attachment) {
-		// The normalized URL will not load files from Discord CDN once the time limit is enforced.
-		
-		// The downloaded URL would work, but only for a limited time, so it is better for the links to not work
-		// rather than give users a false sense of security.
-		
-		return attachment.NormalizedUrl;
-	}
-}

app/Server/Database/Export/ViewerJson.cs

@@ -0,0 +1,93 @@
+using System.Collections.Generic;
+using System.Text.Json.Serialization;
+
+namespace DHT.Server.Database.Export;
+
+sealed class ViewerJson {
+	public required JsonMeta Meta { get; init; }
+	public required Dictionary<Snowflake, Dictionary<Snowflake, JsonMessage>> Data { get; init; }
+
+	public sealed class JsonMeta {
+		public required Dictionary<Snowflake, JsonUser> Users { get; init; }
+		public required List<Snowflake> Userindex { get; init; }
+		public required List<JsonServer> Servers { get; init; }
+		public required Dictionary<Snowflake, JsonChannel> Channels { get; init; }
+	}
+	
+	public sealed class JsonUser {
+		public required string Name { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? Avatar { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? Tag { get; init; }
+	}
+
+	public sealed class JsonServer {
+		public required string Name { get; init; }
+		public required string Type { get; init; }
+	}
+
+	public sealed class JsonChannel {
+		public required int Server { get; init; }
+		public required string Name { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? Parent { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public int? Position { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? Topic { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public bool? Nsfw { get; init; }
+	}
+
+	public sealed class JsonMessage {
+		public required int U { get; init; }
+		public required long T { get; init; }
+
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? M { get; init; }
+
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public long? Te { get; init; }
+
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? R { get; init; }
+
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public JsonMessageAttachment[]? A { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string[]? E { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public JsonMessageReaction[]? Re { get; init; }
+	}
+
+	public sealed class JsonMessageAttachment {
+		public required string Url { get; init; }
+		public required string Name { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public int? Width { get; set; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public int? Height { get; set; }
+	}
+
+	public sealed class JsonMessageReaction {
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? Id { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? N { get; init; }
+
+		public required bool A { get; init; }
+		public required int C { get; init; }
+	}
+}

app/Server/Database/Export/ViewerJsonContext.cs

@@ -0,0 +1,11 @@
+using System.Text.Json.Serialization;
+
+namespace DHT.Server.Database.Export;
+
+[JsonSourceGenerationOptions(
+	Converters = [typeof(SnowflakeJsonSerializer)],
+	PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase,
+	GenerationMode = JsonSourceGenerationMode.Default
+)]
+[JsonSerializable(typeof(ViewerJson))]
+sealed partial class ViewerJsonContext : JsonSerializerContext;

app/Server/Database/Export/ViewerJsonExport.cs

@@ -6,7 +6,6 @@ using System.Text.Json;
 using System.Threading.Tasks;
 using DHT.Server.Data;
 using DHT.Server.Data.Filters;
-using DHT.Server.Database.Export.Strategy;
 using DHT.Utils.Logging;
 
 namespace DHT.Server.Database.Export;
@@ -14,14 +13,14 @@ namespace DHT.Server.Database.Export;
 public static class ViewerJsonExport {
 	private static readonly Log Log = Log.ForType(typeof(ViewerJsonExport));
 
-	public static async Task Generate(Stream stream, IViewerExportStrategy strategy, IDatabaseFile db, MessageFilter? filter = null) {
+	public static async Task Generate(Stream stream, IDatabaseFile db, MessageFilter? filter = null) {
 		var perf = Log.Start();
 
 		var includedUserIds = new HashSet<ulong>();
 		var includedChannelIds = new HashSet<ulong>();
 		var includedServerIds = new HashSet<ulong>();
 
-		var includedMessages = db.GetMessages(filter);
+		var includedMessages = await db.Messages.Get(filter).ToListAsync();
 		var includedChannels = new List<Channel>();
 
 		foreach (var message in includedMessages) {
@@ -29,185 +28,145 @@ public static class ViewerJsonExport {
 			includedChannelIds.Add(message.Channel);
 		}
 
-		foreach (var channel in db.GetAllChannels()) {
+		await foreach (var channel in db.Channels.Get()) {
 			if (includedChannelIds.Contains(channel.Id)) {
 				includedChannels.Add(channel);
 				includedServerIds.Add(channel.Server);
 			}
 		}
 
-		var users = GenerateUserList(db, includedUserIds, out var userindex, out var userIndices);
+		var (users, userIndex, userIndices) = await GenerateUserList(db, includedUserIds);
-		var servers = GenerateServerList(db, includedServerIds, out var serverindex);
+		var (servers, serverIndices) = await GenerateServerList(db, includedServerIds);
-		var channels = GenerateChannelList(includedChannels, serverindex);
+		var channels = GenerateChannelList(includedChannels, serverIndices);
 
 		perf.Step("Collect database data");
 
-		var value = new {
+		var value = new ViewerJson {
-			meta = new { users, userindex, servers, channels },
+			Meta = new ViewerJson.JsonMeta {
-			data = GenerateMessageList(includedMessages, userIndices, strategy),
+				Users = users,
+				Userindex = userIndex,
+				Servers = servers,
+				Channels = channels
+			},
+			Data = GenerateMessageList(includedMessages, userIndices)
 		};
 
 		perf.Step("Generate value object");
 
-		var opts = new JsonSerializerOptions();
+		await JsonSerializer.SerializeAsync(stream, value, ViewerJsonContext.Default.ViewerJson);
-		opts.Converters.Add(new ViewerJsonSnowflakeSerializer());
-
-		await JsonSerializer.SerializeAsync(stream, value, opts);
 
 		perf.Step("Serialize to JSON");
 		perf.End();
 	}
 
-	private static Dictionary<string, object> GenerateUserList(IDatabaseFile db, HashSet<ulong> userIds, out List<string> userindex, out Dictionary<ulong, object> userIndices) {
+	private static async Task<(Dictionary<Snowflake, ViewerJson.JsonUser> Users, List<Snowflake> UserIndex, Dictionary<ulong, int> UserIndices)> GenerateUserList(IDatabaseFile db, HashSet<ulong> userIds) {
-		var users = new Dictionary<string, object>();
+		var users = new Dictionary<Snowflake, ViewerJson.JsonUser>();
-		userindex = new List<string>();
+		var userIndex = new List<Snowflake>();
-		userIndices = new Dictionary<ulong, object>();
+		var userIndices = new Dictionary<ulong, int>();
 
-		foreach (var user in db.GetAllUsers()) {
+		await foreach (var user in db.Users.Get()) {
 			var id = user.Id;
 			if (!userIds.Contains(id)) {
 				continue;
 			}
 
-			var obj = new Dictionary<string, object> {
+			var idSnowflake = new Snowflake(id);
-				["name"] = user.Name
-			};
-
-			if (user.AvatarUrl != null) {
-				obj["avatar"] = user.AvatarUrl;
-			}
-
-			if (user.Discriminator != null) {
-				obj["tag"] = user.Discriminator;
-			}
-
-			var idStr = id.ToString();
 			userIndices[id] = users.Count;
-			userindex.Add(idStr);
+			userIndex.Add(idSnowflake);
-			users[idStr] = obj;
+			
+			users[idSnowflake] = new ViewerJson.JsonUser {
+				Name = user.Name,
+				Avatar = user.AvatarUrl,
+				Tag = user.Discriminator
+			};
 		}
 
-		return users;
+		return (users, userIndex, userIndices);
 	}
 
-	private static List<object> GenerateServerList(IDatabaseFile db, HashSet<ulong> serverIds, out Dictionary<ulong, object> serverIndices) {
+	private static async Task<(List<ViewerJson.JsonServer> Servers, Dictionary<ulong, int> ServerIndices)> GenerateServerList(IDatabaseFile db, HashSet<ulong> serverIds) {
-		var servers = new List<object>();
+		var servers = new List<ViewerJson.JsonServer>();
-		serverIndices = new Dictionary<ulong, object>();
+		var serverIndices = new Dictionary<ulong, int>();
 
-		foreach (var server in db.GetAllServers()) {
+		await foreach (var server in db.Servers.Get()) {
 			var id = server.Id;
 			if (!serverIds.Contains(id)) {
 				continue;
 			}
 
 			serverIndices[id] = servers.Count;
-			servers.Add(new Dictionary<string, object> {
+			
-				["name"] = server.Name,
+			servers.Add(new ViewerJson.JsonServer {
-				["type"] = ServerTypes.ToJsonViewerString(server.Type),
+				Name = server.Name,
+				Type = ServerTypes.ToJsonViewerString(server.Type)
 			});
 		}
 
-		return servers;
+		return (servers, serverIndices);
 	}
 
-	private static Dictionary<string, object> GenerateChannelList(List<Channel> includedChannels, Dictionary<ulong, object> serverIndices) {
+	private static Dictionary<Snowflake, ViewerJson.JsonChannel> GenerateChannelList(List<Channel> includedChannels, Dictionary<ulong, int> serverIndices) {
-		var channels = new Dictionary<string, object>();
+		var channels = new Dictionary<Snowflake, ViewerJson.JsonChannel>();
 
 		foreach (var channel in includedChannels) {
-			var obj = new Dictionary<string, object> {
+			var channelIdSnowflake = new Snowflake(channel.Id);
-				["server"] = serverIndices[channel.Server],
+			
-				["name"] = channel.Name,
+			channels[channelIdSnowflake] = new ViewerJson.JsonChannel {
+				Server = serverIndices[channel.Server],
+				Name = channel.Name,
+				Parent = channel.ParentId?.ToString(),
+				Position = channel.Position,
+				Topic = channel.Topic,
+				Nsfw = channel.Nsfw
 			};
-
-			if (channel.ParentId != null) {
-				obj["parent"] = channel.ParentId;
-			}
-
-			if (channel.Position != null) {
-				obj["position"] = channel.Position;
-			}
-
-			if (channel.Topic != null) {
-				obj["topic"] = channel.Topic;
-			}
-
-			if (channel.Nsfw != null) {
-				obj["nsfw"] = channel.Nsfw;
-			}
-
-			channels[channel.Id.ToString()] = obj;
 		}
 
 		return channels;
 	}
 
-	private static Dictionary<string, Dictionary<string, object>> GenerateMessageList( List<Message> includedMessages, Dictionary<ulong, object> userIndices, IViewerExportStrategy strategy) {
+	private static Dictionary<Snowflake, Dictionary<Snowflake, ViewerJson.JsonMessage>> GenerateMessageList(List<Message> includedMessages, Dictionary<ulong, int> userIndices) {
-		var data = new Dictionary<string, Dictionary<string, object>>();
+		var data = new Dictionary<Snowflake, Dictionary<Snowflake, ViewerJson.JsonMessage>>();
 
 		foreach (var grouping in includedMessages.GroupBy(static message => message.Channel)) {
-			var channel = grouping.Key.ToString();
+			var channelIdSnowflake = new Snowflake(grouping.Key);
-			var channelData = new Dictionary<string, object>();
+			var channelData = new Dictionary<Snowflake, ViewerJson.JsonMessage>();
 
 			foreach (var message in grouping) {
-				var obj = new Dictionary<string, object> {
+				var messageIdSnowflake = new Snowflake(message.Id);
-					["u"] = userIndices[message.Sender],
+				
-					["t"] = message.Timestamp,
+				channelData[messageIdSnowflake] = new ViewerJson.JsonMessage {
-				};
+					U = userIndices[message.Sender],
-
+					T = message.Timestamp,
-				if (!string.IsNullOrEmpty(message.Text)) {
+					M = string.IsNullOrEmpty(message.Text) ? null : message.Text,
-					obj["m"] = message.Text;
+					Te = message.EditTimestamp,
-				}
+					R = message.RepliedToId?.ToString(),
-
+					
-				if (message.EditTimestamp != null) {
+					A = message.Attachments.IsEmpty ? null : message.Attachments.Select(static attachment => {
-					obj["te"] = message.EditTimestamp;
+						var a = new ViewerJson.JsonMessageAttachment {
-				}
+							Url = attachment.DownloadUrl,
-
+							Name = Uri.TryCreate(attachment.NormalizedUrl, UriKind.Absolute, out var uri) ? Path.GetFileName(uri.LocalPath) : attachment.NormalizedUrl
-				if (message.RepliedToId != null) {
-					obj["r"] = message.RepliedToId.Value;
-				}
-
-				if (!message.Attachments.IsEmpty) {
-					obj["a"] = message.Attachments.Select(attachment => {
-						var a = new Dictionary<string, object> {
-							{ "url", strategy.GetAttachmentUrl(attachment) },
-							{ "name", Uri.TryCreate(attachment.NormalizedUrl, UriKind.Absolute, out var uri) ? Path.GetFileName(uri.LocalPath) : attachment.NormalizedUrl },
 						};
 
 						if (attachment is { Width: not null, Height: not null }) {
-							a["width"] = attachment.Width;
+							a.Width = attachment.Width;
-							a["height"] = attachment.Height;
+							a.Height = attachment.Height;
 						}
 
 						return a;
-					}).ToArray();
+					}).ToArray(),
-				}
+					
-
+					E = message.Embeds.IsEmpty ? null : message.Embeds.Select(static embed => embed.Json).ToArray(),
-				if (!message.Embeds.IsEmpty) {
+					
-					obj["e"] = message.Embeds.Select(static embed => embed.Json).ToArray();
+					Re = message.Reactions.IsEmpty ? null : message.Reactions.Select(static reaction => new ViewerJson.JsonMessageReaction {
-				}
+						Id = reaction.EmojiId?.ToString(),
-
+						N = reaction.EmojiName,
-				if (!message.Reactions.IsEmpty) {
+						A = reaction.EmojiFlags.HasFlag(EmojiFlags.Animated),
-					obj["re"] = message.Reactions.Select(static reaction => {
+						C = reaction.Count
-						var r = new Dictionary<string, object>();
+					}).ToArray()
-
+				};
-						if (reaction.EmojiId != null) {
-							r["id"] = reaction.EmojiId.Value;
-						}
-
-						if (reaction.EmojiName != null) {
-							r["n"] = reaction.EmojiName;
-						}
-
-						r["a"] = reaction.EmojiFlags.HasFlag(EmojiFlags.Animated);
-						r["c"] = reaction.Count;
-						return r;
-					}).ToArray();
-				}
-
-				channelData[message.Id.ToString()] = obj;
 			}
 
-			data[channel] = channelData;
+			data[channelIdSnowflake] = channelData;
 		}
 
 		return data;

app/Server/Database/Export/ViewerJsonSnowflakeSerializer.cs

@@ -1,15 +0,0 @@
-using System;
-using System.Text.Json;
-using System.Text.Json.Serialization;
-
-namespace DHT.Server.Database.Export;
-
-sealed class ViewerJsonSnowflakeSerializer : JsonConverter<ulong> {
-	public override ulong Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
-		return ulong.Parse(reader.GetString()!);
-	}
-
-	public override void Write(Utf8JsonWriter writer, ulong value, JsonSerializerOptions options) {
-		writer.WriteStringValue(value.ToString());
-	}
-}

app/Server/Database/IDatabaseFile.cs

@@ -1,43 +1,17 @@
 using System;
-using System.Collections.Generic;
+using System.Threading.Tasks;
-using DHT.Server.Data;
+using DHT.Server.Database.Repositories;
-using DHT.Server.Data.Aggregations;
-using DHT.Server.Data.Filters;
-using DHT.Server.Download;
 
 namespace DHT.Server.Database;
 
-public interface IDatabaseFile : IDisposable {
+public interface IDatabaseFile : IAsyncDisposable {
 	string Path { get; }
-	DatabaseStatistics Statistics { get; }
-	DatabaseStatisticsSnapshot SnapshotStatistics();
 
-	void AddServer(Data.Server server);
+	IUserRepository Users { get; }
-	List<Data.Server> GetAllServers();
+	IServerRepository Servers { get; }
+	IChannelRepository Channels { get; }
+	IMessageRepository Messages { get; }
+	IDownloadRepository Downloads { get; }
 
-	void AddChannel(Channel channel);
+	Task Vacuum();
-	List<Channel> GetAllChannels();
-
-	void AddUsers(User[] users);
-	List<User> GetAllUsers();
-
-	void AddMessages(Message[] messages);
-	int CountMessages(MessageFilter? filter = null);
-	List<Message> GetMessages(MessageFilter? filter = null);
-	HashSet<ulong> GetMessageIds(MessageFilter? filter = null);
-	void RemoveMessages(MessageFilter filter, FilterRemovalMode mode);
-
-	int CountAttachments(AttachmentFilter? filter = null);
-
-	void AddDownload(Data.Download download);
-	List<Data.Download> GetDownloadsWithoutData();
-	Data.Download GetDownloadWithData(Data.Download download);
-	DownloadedAttachment? GetDownloadedAttachment(string url);
-
-	void EnqueueDownloadItems(AttachmentFilter? filter = null);
-	List<DownloadItem> GetEnqueuedDownloadItems(int count);
-	void RemoveDownloadItems(DownloadItemFilter? filter, FilterRemovalMode mode);
-	DownloadStatusStatistics GetDownloadStatusStatistics();
-
-	void Vacuum();
 }

app/Server/Database/Import/DiscordEmbedLegacyJson.cs

@@ -0,0 +1,23 @@
+using System.Text.Json.Serialization;
+
+namespace DHT.Server.Database.Import;
+
+sealed class DiscordEmbedLegacyJson {
+	public required string Url { get; init; }
+	public required string Type { get; init; }
+	
+	public bool DhtLegacy { get; } = true;
+
+	[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+	public string? Title { get; init; }
+	
+	[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+	public string? Description { get; init; }
+
+	[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+	public ImageJson? Image { get; init; }
+
+	public sealed class ImageJson {
+		public required string Url { get; init; }
+	}
+}

app/Server/Database/Import/DiscordEmbedLegacyJsonContext.cs

@@ -0,0 +1,7 @@
+using System.Text.Json.Serialization;
+
+namespace DHT.Server.Database.Import;
+
+[JsonSourceGenerationOptions(PropertyNamingPolicy = JsonKnownNamingPolicy.SnakeCaseLower, GenerationMode = JsonSourceGenerationMode.Default)]
+[JsonSerializable(typeof(DiscordEmbedLegacyJson))]
+sealed partial class DiscordEmbedLegacyJsonContext : JsonSerializerContext;

app/Server/Database/Import/LegacyArchiveImport.cs

@@ -21,7 +21,7 @@ public static class LegacyArchiveImport {
 
 	public static async Task<bool> Read(Stream stream, IDatabaseFile db, FakeSnowflake fakeSnowflake, Func<Data.Server[], Task<Dictionary<Data.Server, ulong>?>> askForServerIds) {
 		var perf = Log.Start();
-		var root = await JsonSerializer.DeserializeAsync<JsonElement>(stream);
+		var root = await JsonSerializer.DeserializeAsync(stream, JsonElementContext.Default.JsonElement);
 
 		try {
 			var meta = root.RequireObject("meta");
@@ -33,10 +33,8 @@ public static class LegacyArchiveImport {
 			var servers = ReadServerList(meta, fakeSnowflake);
 
 			var newServersOnly = new HashSet<Data.Server>(servers);
-			var oldServersById = db.GetAllServers().ToDictionary(static server => server.Id, static server => server);
+			var oldServersById = await db.Servers.Get().ToDictionaryAsync(static server => server.Id, static server => server);
-
+			var oldChannelsById = await db.Channels.Get().ToDictionaryAsync(static channel => channel.Id, static channel => channel);
-			var oldChannels = db.GetAllChannels();
-			var oldChannelsById = oldChannels.ToDictionary(static channel => channel.Id, static channel => channel);
 
 			foreach (var (channelId, serverIndex) in ReadChannelToServerIndexMapping(meta, servers)) {
 				if (oldChannelsById.TryGetValue(channelId, out var oldChannel) && oldServersById.TryGetValue(oldChannel.Server, out var oldServer) && newServersOnly.Remove(servers[serverIndex])) {
@@ -66,17 +64,17 @@ public static class LegacyArchiveImport {
 
 			perf.Step("Read channel list");
 
-			var oldMessageIds = db.GetMessageIds();
+			var oldMessageIds = await db.Messages.GetIds().ToHashSetAsync();
 			var newMessages = channels.SelectMany(channel => ReadMessages(data, channel, users, fakeSnowflake))
 			                          .Where(message => !oldMessageIds.Contains(message.Id))
 			                          .ToArray();
 
 			perf.Step("Read messages");
 
-			db.AddUsers(users);
+			await db.Users.Add(users);
-			db.AddServers(servers);
+			await db.Servers.Add(servers);
-			db.AddChannels(channels);
+			await db.Channels.Add(channels);
-			db.AddMessages(newMessages);
+			await db.Messages.Add(newMessages);
 
 			perf.Step("Import into database");
 		} catch (HttpException e) {
@@ -163,7 +161,7 @@ public static class LegacyArchiveImport {
 
 		var messagesObj = data.HasKey(channelIdStr) ? data.RequireObject(channelIdStr, DataPath) : (JsonElement?) null;
 		if (messagesObj == null) {
-			return Array.Empty<Message>();
+			return [];
 		}
 
 		return messagesObj.Value.EnumerateObject().Select(item => {
@@ -179,9 +177,9 @@ public static class LegacyArchiveImport {
 				Timestamp = messageObj.RequireLong("t", path),
 				EditTimestamp = messageObj.HasKey("te") ? messageObj.RequireLong("te", path) : null,
 				RepliedToId = messageObj.HasKey("r") ? messageObj.RequireSnowflake("r", path) : null,
-				Attachments = messageObj.HasKey("a") ? ReadMessageAttachments(messageObj.RequireArray("a", path), fakeSnowflake, path + ".a[]").ToImmutableArray() : ImmutableArray<Attachment>.Empty,
+				Attachments = messageObj.HasKey("a") ? ReadMessageAttachments(messageObj.RequireArray("a", path), fakeSnowflake, path + ".a[]").ToImmutableList() : ImmutableList<Attachment>.Empty,
-				Embeds = messageObj.HasKey("e") ? ReadMessageEmbeds(messageObj.RequireArray("e", path), path + ".e[]").ToImmutableArray() : ImmutableArray<Embed>.Empty,
+				Embeds = messageObj.HasKey("e") ? ReadMessageEmbeds(messageObj.RequireArray("e", path), path + ".e[]").ToImmutableList() : ImmutableList<Embed>.Empty,
-				Reactions = messageObj.HasKey("re") ? ReadMessageReactions(messageObj.RequireArray("re", path), path + ".re[]").ToImmutableArray() : ImmutableArray<Reaction>.Empty,
+				Reactions = messageObj.HasKey("re") ? ReadMessageReactions(messageObj.RequireArray("re", path), path + ".re[]").ToImmutableList() : ImmutableList<Reaction>.Empty,
 			};
 		}).ToArray();
 	}
@@ -212,30 +210,17 @@ public static class LegacyArchiveImport {
 		return embedsArray.Where(static embedObj => embedObj.HasKey("url")).Select(embedObj => {
 			string url = embedObj.RequireString("url", path);
 			string type = embedObj.RequireString("type", path);
-
+			
-			var embedJson = new Dictionary<string, object> {
+			var embed = new DiscordEmbedLegacyJson {
-				{ "url", url },
+				Url = url,
-				{ "type", type },
+				Type = type,
-				{ "dht_legacy", true },
+				Title = type == "rich" && embedObj.HasKey("t") ? embedObj.RequireString("t", path) : null,
+				Description = type == "rich" && embedObj.HasKey("d") ? embedObj.RequireString("d", path) : null,
+				Image = type == "image" ? new DiscordEmbedLegacyJson.ImageJson { Url = url } : null
 			};
 
-			if (type == "image") {
-				embedJson["image"] = new Dictionary<string, string> {
-					{ "url", url }
-				};
-			}
-			else if (type == "rich") {
-				if (embedObj.HasKey("t")) {
-					embedJson["title"] = embedObj.RequireString("t", path);
-				}
-
-				if (embedObj.HasKey("d")) {
-					embedJson["description"] = embedObj.RequireString("d", path);
-				}
-			}
-
 			return new Embed {
-				Json = JsonSerializer.Serialize(embedJson)
+				Json = JsonSerializer.Serialize(embed, DiscordEmbedLegacyJsonContext.Default.DiscordEmbedLegacyJson)
 			};
 		});
 	}

app/Server/Database/Repositories/IChannelRepository.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reactive.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+
+namespace DHT.Server.Database.Repositories;
+
+public interface IChannelRepository {
+	IObservable<long> TotalCount { get; }
+	
+	Task Add(IReadOnlyList<Channel> channels);
+	
+	Task<long> Count(CancellationToken cancellationToken = default);
+	
+	IAsyncEnumerable<Channel> Get();
+
+	internal sealed class Dummy : IChannelRepository {
+		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+
+		public Task Add(IReadOnlyList<Channel> channels) {
+			return Task.CompletedTask;
+		}
+
+		public Task<long> Count(CancellationToken cancellationToken) {
+			return Task.FromResult(0L);
+		}
+
+		public IAsyncEnumerable<Channel> Get() {
+			return AsyncEnumerable.Empty<Channel>();
+		}
+	}
+}

app/Server/Database/Repositories/IDownloadRepository.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Reactive.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data.Aggregations;
+using DHT.Server.Data.Filters;
+using DHT.Server.Download;
+
+namespace DHT.Server.Database.Repositories;
+
+public interface IDownloadRepository {
+	IObservable<long> TotalCount { get; }
+
+	Task AddDownload(Data.Download item, Stream? stream);
+
+	Task<long> Count(DownloadItemFilter filter, CancellationToken cancellationToken = default);
+	
+	Task<DownloadStatusStatistics> GetStatistics(DownloadItemFilter nonSkippedFilter, CancellationToken cancellationToken = default);
+	
+	IAsyncEnumerable<Data.Download> Get();
+
+	Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor);
+	
+	Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, Task> dataProcessor);
+
+	IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, CancellationToken cancellationToken = default);
+	
+	Task MoveDownloadingItemsBackToQueue(CancellationToken cancellationToken = default);
+	
+	Task<int> RetryFailed(CancellationToken cancellationToken = default);
+
+	internal sealed class Dummy : IDownloadRepository {
+		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+
+		public Task AddDownload(Data.Download item, Stream? stream) {
+			return Task.CompletedTask;
+		}
+
+		public Task<long> Count(DownloadItemFilter filter, CancellationToken cancellationToken) {
+			return Task.FromResult(0L);
+		}
+
+		public Task<DownloadStatusStatistics> GetStatistics(DownloadItemFilter nonSkippedFilter, CancellationToken cancellationToken) {
+			return Task.FromResult(new DownloadStatusStatistics());
+		}
+
+		public IAsyncEnumerable<Data.Download> Get() {
+			return AsyncEnumerable.Empty<Data.Download>();
+		}
+
+		public Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor) {
+			return Task.FromResult(false);
+		}
+
+		public Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, Task> dataProcessor) {
+			return Task.FromResult(false);
+		}
+
+		public IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, CancellationToken cancellationToken) {
+			return AsyncEnumerable.Empty<DownloadItem>();
+		}
+
+		public Task MoveDownloadingItemsBackToQueue(CancellationToken cancellationToken) {
+			return Task.CompletedTask;
+		}
+
+		public Task<int> RetryFailed(CancellationToken cancellationToken) {
+			return Task.FromResult(0);
+		}
+	}
+}

app/Server/Database/Repositories/IMessageRepository.cs

@@ -0,0 +1,48 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reactive.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+using DHT.Server.Data.Filters;
+
+namespace DHT.Server.Database.Repositories;
+
+public interface IMessageRepository {
+	IObservable<long> TotalCount { get; }
+	
+	Task Add(IReadOnlyList<Message> messages);
+	
+	Task<long> Count(MessageFilter? filter = null, CancellationToken cancellationToken = default);
+	
+	IAsyncEnumerable<Message> Get(MessageFilter? filter = null);
+	
+	IAsyncEnumerable<ulong> GetIds(MessageFilter? filter = null);
+	
+	Task Remove(MessageFilter filter, FilterRemovalMode mode);
+
+	internal sealed class Dummy : IMessageRepository {
+		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+
+		public Task Add(IReadOnlyList<Message> messages) {
+			return Task.CompletedTask;
+		}
+
+		public Task<long> Count(MessageFilter? filter, CancellationToken cancellationToken) {
+			return Task.FromResult(0L);
+		}
+
+		public IAsyncEnumerable<Message> Get(MessageFilter? filter) {
+			return AsyncEnumerable.Empty<Message>();
+		}
+
+		public IAsyncEnumerable<ulong> GetIds(MessageFilter? filter) {
+			return AsyncEnumerable.Empty<ulong>();
+		}
+
+		public Task Remove(MessageFilter filter, FilterRemovalMode mode) {
+			return Task.CompletedTask;
+		}
+	}
+}

app/Server/Database/Repositories/IServerRepository.cs

@@ -0,0 +1,34 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reactive.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace DHT.Server.Database.Repositories;
+
+public interface IServerRepository {
+	IObservable<long> TotalCount { get; }
+	
+	Task Add(IReadOnlyList<Data.Server> servers);
+	
+	Task<long> Count(CancellationToken cancellationToken = default);
+	
+	IAsyncEnumerable<Data.Server> Get();
+
+	internal sealed class Dummy : IServerRepository {
+		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+
+		public Task Add(IReadOnlyList<Data.Server> servers) {
+			return Task.CompletedTask;
+		}
+
+		public Task<long> Count(CancellationToken cancellationToken) {
+			return Task.FromResult(0L);
+		}
+
+		public IAsyncEnumerable<Data.Server> Get() {
+			return AsyncEnumerable.Empty<Data.Server>();
+		}
+	}
+}

app/Server/Database/Repositories/IUserRepository.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reactive.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+
+namespace DHT.Server.Database.Repositories;
+
+public interface IUserRepository {
+	IObservable<long> TotalCount { get; }
+	
+	Task Add(IReadOnlyList<User> users);
+	
+	Task<long> Count(CancellationToken cancellationToken = default);
+	
+	IAsyncEnumerable<User> Get();
+
+	internal sealed class Dummy : IUserRepository {
+		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+
+		public Task Add(IReadOnlyList<User> users) {
+			return Task.CompletedTask;
+		}
+
+		public Task<long> Count(CancellationToken cancellationToken) {
+			return Task.FromResult(0L);
+		}
+
+		public IAsyncEnumerable<User> Get() {
+			return AsyncEnumerable.Empty<User>();
+		}
+	}
+}

app/Server/Database/Sqlite/Repositories/BaseSqliteRepository.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Reactive.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Utils.Logging;
+using DHT.Utils.Tasks;
+
+namespace DHT.Server.Database.Sqlite.Repositories;
+
+abstract class BaseSqliteRepository : IDisposable {
+	private readonly ObservableThrottledTask<long> totalCountTask;
+
+	public IObservable<long> TotalCount { get; }
+
+	protected BaseSqliteRepository(Log log) {
+		totalCountTask = new ObservableThrottledTask<long>(log, TaskScheduler.Default);
+		TotalCount = totalCountTask.DistinctUntilChanged();
+		UpdateTotalCount();
+	}
+
+	public void Dispose() {
+		totalCountTask.Dispose();
+	}
+
+	protected void UpdateTotalCount() {
+		totalCountTask.Post(Count);
+	}
+
+	public abstract Task<long> Count(CancellationToken cancellationToken);
+}

app/Server/Database/Sqlite/Repositories/SqliteChannelRepository.cs

@@ -0,0 +1,75 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+using DHT.Server.Database.Repositories;
+using DHT.Server.Database.Sqlite.Utils;
+using DHT.Utils.Logging;
+using Microsoft.Data.Sqlite;
+
+namespace DHT.Server.Database.Sqlite.Repositories;
+
+sealed class SqliteChannelRepository : BaseSqliteRepository, IChannelRepository {
+	private static readonly Log Log = Log.ForType<SqliteChannelRepository>();
+	
+	private readonly SqliteConnectionPool pool;
+
+	public SqliteChannelRepository(SqliteConnectionPool pool) : base(Log) {
+		this.pool = pool;
+	}
+
+	public async Task Add(IReadOnlyList<Channel> channels) {
+		await using (var conn = await pool.Take()) {
+			await conn.BeginTransactionAsync();
+			
+			await using var cmd = conn.Upsert("channels", [
+				("id", SqliteType.Integer),
+				("server", SqliteType.Integer),
+				("name", SqliteType.Text),
+				("parent_id", SqliteType.Integer),
+				("position", SqliteType.Integer),
+				("topic", SqliteType.Text),
+				("nsfw", SqliteType.Integer)
+			]);
+
+			foreach (var channel in channels) {
+				cmd.Set(":id", channel.Id);
+				cmd.Set(":server", channel.Server);
+				cmd.Set(":name", channel.Name);
+				cmd.Set(":parent_id", channel.ParentId);
+				cmd.Set(":position", channel.Position);
+				cmd.Set(":topic", channel.Topic);
+				cmd.Set(":nsfw", channel.Nsfw);
+				await cmd.ExecuteNonQueryAsync();
+			}
+
+			await conn.CommitTransactionAsync();
+		}
+
+		UpdateTotalCount();
+	}
+
+	public override async Task<long> Count(CancellationToken cancellationToken) {
+		await using var conn = await pool.Take();
+		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM channels", static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
+	}
+
+	public async IAsyncEnumerable<Channel> Get() {
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command("SELECT id, server, name, parent_id, position, topic, nsfw FROM channels");
+		await using var reader = await cmd.ExecuteReaderAsync();
+
+		while (await reader.ReadAsync()) {
+			yield return new Channel {
+				Id = reader.GetUint64(0),
+				Server = reader.GetUint64(1),
+				Name = reader.GetString(2),
+				ParentId = reader.IsDBNull(3) ? null : reader.GetUint64(3),
+				Position = reader.IsDBNull(4) ? null : reader.GetInt32(4),
+				Topic = reader.IsDBNull(5) ? null : reader.GetString(5),
+				Nsfw = reader.IsDBNull(6) ? null : reader.GetBoolean(6),
+			};
+		}
+	}
+}

app/Server/Database/Sqlite/Repositories/SqliteDownloadRepository.cs

@@ -0,0 +1,313 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Runtime.CompilerServices;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+using DHT.Server.Data.Aggregations;
+using DHT.Server.Data.Filters;
+using DHT.Server.Database.Repositories;
+using DHT.Server.Database.Sqlite.Utils;
+using DHT.Server.Download;
+using DHT.Utils.Logging;
+using Microsoft.Data.Sqlite;
+
+namespace DHT.Server.Database.Sqlite.Repositories;
+
+sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRepository(Log), IDownloadRepository {
+	private static readonly Log Log = Log.ForType<SqliteDownloadRepository>();
+
+	internal sealed class NewDownloadCollector : IAsyncDisposable {
+		private readonly SqliteDownloadRepository repository;
+		private bool hasAdded = false;
+
+		private readonly SqliteCommand metadataCmd;
+
+		public NewDownloadCollector(SqliteDownloadRepository repository, ISqliteConnection conn) {
+			this.repository = repository;
+
+			metadataCmd = conn.Command(
+				"""
+				INSERT INTO download_metadata (normalized_url, download_url, status, type, size)
+				VALUES (:normalized_url, :download_url, :status, :type, :size)
+				ON CONFLICT DO NOTHING
+				"""
+			);
+			metadataCmd.Add(":normalized_url", SqliteType.Text);
+			metadataCmd.Add(":download_url", SqliteType.Text);
+			metadataCmd.Add(":status", SqliteType.Integer);
+			metadataCmd.Add(":type", SqliteType.Text);
+			metadataCmd.Add(":size", SqliteType.Integer);
+		}
+
+		public async Task Add(Data.Download download) {
+			metadataCmd.Set(":normalized_url", download.NormalizedUrl);
+			metadataCmd.Set(":download_url", download.DownloadUrl);
+			metadataCmd.Set(":status", (int) download.Status);
+			metadataCmd.Set(":type", download.Type);
+			metadataCmd.Set(":size", download.Size);
+			hasAdded |= await metadataCmd.ExecuteNonQueryAsync() > 0;
+		}
+
+		public void OnCommitted() {
+			if (hasAdded) {
+				repository.UpdateTotalCount();
+			}
+		}
+
+		public async ValueTask DisposeAsync() {
+			await metadataCmd.DisposeAsync();
+		}
+	}
+
+	public async Task AddDownload(Data.Download item, Stream? stream) {
+		await using (var conn = await pool.Take()) {
+			await conn.BeginTransactionAsync();
+			
+			await using var metadataCmd = conn.Upsert("download_metadata", [
+				("normalized_url", SqliteType.Text),
+				("download_url", SqliteType.Text),
+				("status", SqliteType.Integer),
+				("type", SqliteType.Text),
+				("size", SqliteType.Integer),
+			]);
+
+			metadataCmd.Set(":normalized_url", item.NormalizedUrl);
+			metadataCmd.Set(":download_url", item.DownloadUrl);
+			metadataCmd.Set(":status", (int) item.Status);
+			metadataCmd.Set(":type", item.Type);
+			metadataCmd.Set(":size", item.Size);
+			await metadataCmd.ExecuteNonQueryAsync();
+
+			if (stream == null) {
+				await using var deleteBlobCmd = conn.Command("DELETE FROM download_blobs WHERE normalized_url = :normalized_url");
+				deleteBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, item.NormalizedUrl);
+				await deleteBlobCmd.ExecuteNonQueryAsync();
+			}
+			else {
+				await using var upsertBlobCmd = conn.Command(
+					"""
+					INSERT INTO download_blobs (normalized_url, blob)
+					VALUES (:normalized_url, ZEROBLOB(:blob_length))
+					ON CONFLICT (normalized_url) DO UPDATE SET blob = excluded.blob
+					RETURNING rowid
+					"""
+				);
+				
+				upsertBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, item.NormalizedUrl);
+				upsertBlobCmd.AddAndSet(":blob_length", SqliteType.Integer, item.Size);
+				long rowid = await upsertBlobCmd.ExecuteLongScalarAsync();
+
+				await using var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid);
+				await stream.CopyToAsync(blob);
+			}
+
+			await conn.CommitTransactionAsync();
+		}
+
+		UpdateTotalCount();
+	}
+
+	public override Task<long> Count(CancellationToken cancellationToken) {
+		return Count(filter: null, cancellationToken);
+	}
+
+	public async Task<long> Count(DownloadItemFilter? filter, CancellationToken cancellationToken) {
+		await using var conn = await pool.Take();
+		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM download_metadata" + filter.GenerateConditions().BuildWhereClause(), static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
+	}
+
+	public async Task<DownloadStatusStatistics> GetStatistics(DownloadItemFilter nonSkippedFilter, CancellationToken cancellationToken) {
+		nonSkippedFilter.IncludeStatuses = null;
+		nonSkippedFilter.ExcludeStatuses = null;
+		string nonSkippedFilterConditions = nonSkippedFilter.GenerateConditions().Build();
+
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command(
+			$"""
+			 SELECT
+			 IFNULL(SUM(CASE WHEN (status = :downloading) OR (status = :pending AND {nonSkippedFilterConditions}) THEN 1 ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN (status = :downloading) OR (status = :pending AND {nonSkippedFilterConditions}) THEN IFNULL(size, 0) ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN ((status = :downloading) OR (status = :pending AND {nonSkippedFilterConditions})) AND size IS NULL THEN 1 ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status = :success THEN 1 ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status = :success THEN IFNULL(size, 0) ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status = :success AND size IS NULL THEN 1 ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status NOT IN (:pending, :downloading, :success) THEN 1 ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status NOT IN (:pending, :downloading, :success) THEN IFNULL(size, 0) ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status NOT IN (:pending, :downloading, :success) AND size IS NULL THEN 1 ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status = :pending AND NOT ({nonSkippedFilterConditions}) THEN 1 ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status = :pending AND NOT ({nonSkippedFilterConditions}) THEN IFNULL(size, 0) ELSE 0 END), 0),
+			 IFNULL(SUM(CASE WHEN status = :pending AND NOT ({nonSkippedFilterConditions}) AND size IS NULL THEN 1 ELSE 0 END), 0)
+			 FROM download_metadata
+			 """
+		);
+
+		cmd.AddAndSet(":pending", SqliteType.Integer, (int) DownloadStatus.Pending);
+		cmd.AddAndSet(":downloading", SqliteType.Integer, (int) DownloadStatus.Downloading);
+		cmd.AddAndSet(":success", SqliteType.Integer, (int) DownloadStatus.Success);
+
+		await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
+
+		if (!await reader.ReadAsync(cancellationToken)) {
+			return new DownloadStatusStatistics();
+		}
+
+		return new DownloadStatusStatistics {
+			PendingCount = reader.GetInt32(0),
+			PendingTotalSize = reader.GetUint64(1),
+			PendingWithUnknownSizeCount = reader.GetInt32(2),
+			SuccessfulCount = reader.GetInt32(3),
+			SuccessfulTotalSize = reader.GetUint64(4),
+			SuccessfulWithUnknownSizeCount = reader.GetInt32(5),
+			FailedCount = reader.GetInt32(6),
+			FailedTotalSize = reader.GetUint64(7),
+			FailedWithUnknownSizeCount = reader.GetInt32(8),
+			SkippedCount = reader.GetInt32(9),
+			SkippedTotalSize = reader.GetUint64(10),
+			SkippedWithUnknownSizeCount = reader.GetInt32(11)
+		};
+	}
+
+	public async IAsyncEnumerable<Data.Download> Get() {
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command("SELECT normalized_url, download_url, status, type, size FROM download_metadata");
+		await using var reader = await cmd.ExecuteReaderAsync();
+
+		while (await reader.ReadAsync()) {
+			string normalizedUrl = reader.GetString(0);
+			string downloadUrl = reader.GetString(1);
+			var status = (DownloadStatus) reader.GetInt32(2);
+			string? type = reader.IsDBNull(3) ? null : reader.GetString(3);
+			ulong? size = reader.IsDBNull(4) ? null : reader.GetUint64(4);
+
+			yield return new Data.Download(normalizedUrl, downloadUrl, status, type, size);
+		}
+	}
+
+	public async Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor) {
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command("SELECT rowid FROM download_blobs WHERE normalized_url = :normalized_url");
+		cmd.AddAndSet(":normalized_url", SqliteType.Text, normalizedUrl);
+		
+		long rowid;
+		
+		await using (var reader = await cmd.ExecuteReaderAsync()) {
+			if (!await reader.ReadAsync()) {
+				return false;
+			}
+
+			rowid = reader.GetInt64(0);
+		}
+		
+		await using (var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid, readOnly: true)) {
+			await dataProcessor(blob);
+		}
+
+		return true;
+	}
+
+	public async Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, Task> dataProcessor) {
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command(
+			"""
+			SELECT dm.download_url, dm.type, db.rowid FROM download_metadata dm
+			JOIN download_blobs db ON dm.normalized_url = db.normalized_url
+			WHERE dm.normalized_url = :normalized_url AND dm.status = :success IS NOT NULL
+			"""
+		);
+
+		cmd.AddAndSet(":normalized_url", SqliteType.Text, normalizedUrl);
+		cmd.AddAndSet(":success", SqliteType.Integer, (int) DownloadStatus.Success);
+
+		string downloadUrl;
+		string? type;
+		long rowid;
+		
+		await using (var reader = await cmd.ExecuteReaderAsync()) {
+			if (!await reader.ReadAsync()) {
+				return false;
+			}
+
+			downloadUrl = reader.GetString(0);
+			type = reader.IsDBNull(1) ? null : reader.GetString(1);
+			rowid = reader.GetInt64(2);
+		}
+		
+		await using (var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid, readOnly: true)) {
+			await dataProcessor(new Data.Download(normalizedUrl, downloadUrl, DownloadStatus.Success, type, (ulong) blob.Length), blob);
+		}
+
+		return true;
+	}
+
+	public async IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, [EnumeratorCancellation] CancellationToken cancellationToken) {
+		filter.IncludeStatuses = [DownloadStatus.Pending];
+		filter.ExcludeStatuses = null;
+
+		var found = new List<DownloadItem>();
+
+		await using var conn = await pool.Take();
+
+		var sql = $"""
+		           SELECT normalized_url, download_url, type, size
+		           FROM download_metadata
+		           {filter.GenerateConditions().BuildWhereClause()}
+		           LIMIT :limit
+		           """;
+
+		await using (var cmd = conn.Command(sql)) {
+			cmd.AddAndSet(":limit", SqliteType.Integer, Math.Max(0, count));
+
+			await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
+
+			while (await reader.ReadAsync(cancellationToken)) {
+				found.Add(new DownloadItem {
+					NormalizedUrl = reader.GetString(0),
+					DownloadUrl = reader.GetString(1),
+					Type = reader.IsDBNull(2) ? null : reader.GetString(2),
+					Size = reader.IsDBNull(3) ? null : reader.GetUint64(3)
+				});
+			}
+		}
+
+		if (found.Count != 0) {
+			await using var cmd = conn.Command("UPDATE download_metadata SET status = :downloading WHERE normalized_url = :normalized_url AND status = :pending");
+			cmd.AddAndSet(":pending", SqliteType.Integer, (int) DownloadStatus.Pending);
+			cmd.AddAndSet(":downloading", SqliteType.Integer, (int) DownloadStatus.Downloading);
+			cmd.Add(":normalized_url", SqliteType.Text);
+
+			foreach (var item in found) {
+				cmd.Set(":normalized_url", item.NormalizedUrl);
+
+				if (await cmd.ExecuteNonQueryAsync(cancellationToken) == 1) {
+					yield return item;
+				}
+			}
+		}
+	}
+
+	public async Task MoveDownloadingItemsBackToQueue(CancellationToken cancellationToken) {
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command("UPDATE download_metadata SET status = :pending WHERE status = :downloading");
+		cmd.AddAndSet(":pending", SqliteType.Integer, (int) DownloadStatus.Pending);
+		cmd.AddAndSet(":downloading", SqliteType.Integer, (int) DownloadStatus.Downloading);
+		await cmd.ExecuteNonQueryAsync(cancellationToken);
+	}
+
+	public async Task<int> RetryFailed(CancellationToken cancellationToken) {
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command("UPDATE download_metadata SET status = :pending WHERE status = :generic_error OR (status > :last_custom_code AND status != :success)");
+		cmd.AddAndSet(":pending", SqliteType.Integer, (int) DownloadStatus.Pending);
+		cmd.AddAndSet(":generic_error", SqliteType.Integer, (int) DownloadStatus.GenericError);
+		cmd.AddAndSet(":last_custom_code", SqliteType.Integer, (int) DownloadStatus.LastCustomCode);
+		cmd.AddAndSet(":success", SqliteType.Integer, (int) DownloadStatus.Success);
+		return await cmd.ExecuteNonQueryAsync(cancellationToken);
+	}
+}

app/Server/Database/Sqlite/Repositories/SqliteMessageRepository.cs

@@ -0,0 +1,316 @@
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+using DHT.Server.Data.Filters;
+using DHT.Server.Database.Repositories;
+using DHT.Server.Database.Sqlite.Utils;
+using DHT.Server.Download;
+using DHT.Utils.Logging;
+using Microsoft.Data.Sqlite;
+
+namespace DHT.Server.Database.Sqlite.Repositories;
+
+sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository {
+	private static readonly Log Log = Log.ForType<SqliteMessageRepository>();
+	
+	private readonly SqliteConnectionPool pool;
+	private readonly SqliteDownloadRepository downloads;
+
+	public SqliteMessageRepository(SqliteConnectionPool pool, SqliteDownloadRepository downloads) : base(Log) {
+		this.pool = pool;
+		this.downloads = downloads;
+	}
+
+	public async Task Add(IReadOnlyList<Message> messages) {
+		if (messages.Count == 0) {
+			return;
+		}
+
+		static SqliteCommand DeleteByMessageId(ISqliteConnection conn, string tableName) {
+			return conn.Delete(tableName, ("message_id", SqliteType.Integer));
+		}
+
+		static async Task ExecuteDeleteByMessageId(SqliteCommand cmd, object id) {
+			cmd.Set(":message_id", id);
+			await cmd.ExecuteNonQueryAsync();
+		}
+
+		await using (var conn = await pool.Take()) {
+			await conn.BeginTransactionAsync();
+
+			await using var messageCmd = conn.Upsert("messages", [
+				("message_id", SqliteType.Integer),
+				("sender_id", SqliteType.Integer),
+				("channel_id", SqliteType.Integer),
+				("text", SqliteType.Text),
+				("timestamp", SqliteType.Integer)
+			]);
+
+			await using var deleteEditTimestampCmd = DeleteByMessageId(conn, "edit_timestamps");
+			await using var deleteRepliedToCmd = DeleteByMessageId(conn, "replied_to");
+
+			await using var deleteAttachmentsCmd = DeleteByMessageId(conn, "attachments");
+			await using var deleteEmbedsCmd = DeleteByMessageId(conn, "embeds");
+			await using var deleteReactionsCmd = DeleteByMessageId(conn, "reactions");
+
+			await using var editTimestampCmd = conn.Insert("edit_timestamps", [
+				("message_id", SqliteType.Integer),
+				("edit_timestamp", SqliteType.Integer)
+			]);
+
+			await using var repliedToCmd = conn.Insert("replied_to", [
+				("message_id", SqliteType.Integer),
+				("replied_to_id", SqliteType.Integer)
+			]);
+
+			await using var attachmentCmd = conn.Insert("attachments", [
+				("message_id", SqliteType.Integer),
+				("attachment_id", SqliteType.Integer),
+				("name", SqliteType.Text),
+				("type", SqliteType.Text),
+				("normalized_url", SqliteType.Text),
+				("download_url", SqliteType.Text),
+				("size", SqliteType.Integer),
+				("width", SqliteType.Integer),
+				("height", SqliteType.Integer)
+			]);
+
+			await using var embedCmd = conn.Insert("embeds", [
+				("message_id", SqliteType.Integer),
+				("json", SqliteType.Text)
+			]);
+
+			await using var reactionCmd = conn.Insert("reactions", [
+				("message_id", SqliteType.Integer),
+				("emoji_id", SqliteType.Integer),
+				("emoji_name", SqliteType.Text),
+				("emoji_flags", SqliteType.Integer),
+				("count", SqliteType.Integer)
+			]);
+			
+			await using var downloadCollector = new SqliteDownloadRepository.NewDownloadCollector(downloads, conn);
+
+			foreach (var message in messages) {
+				object messageId = message.Id;
+
+				messageCmd.Set(":message_id", messageId);
+				messageCmd.Set(":sender_id", message.Sender);
+				messageCmd.Set(":channel_id", message.Channel);
+				messageCmd.Set(":text", message.Text);
+				messageCmd.Set(":timestamp", message.Timestamp);
+				await messageCmd.ExecuteNonQueryAsync();
+
+				await ExecuteDeleteByMessageId(deleteEditTimestampCmd, messageId);
+				await ExecuteDeleteByMessageId(deleteRepliedToCmd, messageId);
+
+				await ExecuteDeleteByMessageId(deleteAttachmentsCmd, messageId);
+				await ExecuteDeleteByMessageId(deleteEmbedsCmd, messageId);
+				await ExecuteDeleteByMessageId(deleteReactionsCmd, messageId);
+
+				if (message.EditTimestamp is {} timestamp) {
+					editTimestampCmd.Set(":message_id", messageId);
+					editTimestampCmd.Set(":edit_timestamp", timestamp);
+					await editTimestampCmd.ExecuteNonQueryAsync();
+				}
+
+				if (message.RepliedToId is {} repliedToId) {
+					repliedToCmd.Set(":message_id", messageId);
+					repliedToCmd.Set(":replied_to_id", repliedToId);
+					await repliedToCmd.ExecuteNonQueryAsync();
+				}
+
+				if (!message.Attachments.IsEmpty) {
+					foreach (var attachment in message.Attachments) {
+						attachmentCmd.Set(":message_id", messageId);
+						attachmentCmd.Set(":attachment_id", attachment.Id);
+						attachmentCmd.Set(":name", attachment.Name);
+						attachmentCmd.Set(":type", attachment.Type);
+						attachmentCmd.Set(":normalized_url", attachment.NormalizedUrl);
+						attachmentCmd.Set(":download_url", attachment.DownloadUrl);
+						attachmentCmd.Set(":size", attachment.Size);
+						attachmentCmd.Set(":width", attachment.Width);
+						attachmentCmd.Set(":height", attachment.Height);
+						await attachmentCmd.ExecuteNonQueryAsync();
+						
+						await downloadCollector.Add(DownloadLinkExtractor.FromAttachment(attachment));
+					}
+				}
+
+				if (!message.Embeds.IsEmpty) {
+					foreach (var embed in message.Embeds) {
+						embedCmd.Set(":message_id", messageId);
+						embedCmd.Set(":json", embed.Json);
+						await embedCmd.ExecuteNonQueryAsync();
+
+						if (DownloadLinkExtractor.TryFromEmbedJson(embed.Json) is {} download) {
+							await downloadCollector.Add(download);
+						}
+					}
+				}
+
+				if (!message.Reactions.IsEmpty) {
+					foreach (var reaction in message.Reactions) {
+						reactionCmd.Set(":message_id", messageId);
+						reactionCmd.Set(":emoji_id", reaction.EmojiId);
+						reactionCmd.Set(":emoji_name", reaction.EmojiName);
+						reactionCmd.Set(":emoji_flags", (int) reaction.EmojiFlags);
+						reactionCmd.Set(":count", reaction.Count);
+						await reactionCmd.ExecuteNonQueryAsync();
+
+						if (reaction.EmojiId is {} emojiId) {
+							await downloadCollector.Add(DownloadLinkExtractor.FromEmoji(emojiId, reaction.EmojiFlags));
+						}
+					}
+				}
+			}
+
+			await conn.CommitTransactionAsync();
+			downloadCollector.OnCommitted();
+		}
+
+		UpdateTotalCount();
+	}
+
+	public override Task<long> Count(CancellationToken cancellationToken) {
+		return Count(filter: null, cancellationToken);
+	}
+	
+	public async Task<long> Count(MessageFilter? filter, CancellationToken cancellationToken) {
+		await using var conn = await pool.Take();
+		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM messages" + filter.GenerateConditions().BuildWhereClause(), static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
+	}
+
+	private sealed class MessageToManyCommand<T> : IAsyncDisposable {
+		private readonly SqliteCommand cmd;
+		private readonly Func<SqliteDataReader, T> readItem;
+
+		public MessageToManyCommand(ISqliteConnection conn, string sql, Func<SqliteDataReader, T> readItem) {
+			this.cmd = conn.Command(sql);
+			this.cmd.Add(":message_id", SqliteType.Integer);
+
+			this.readItem = readItem;
+		}
+
+		public async Task<ImmutableList<T>> GetItems(ulong messageId) {
+			cmd.Set(":message_id", messageId);
+
+			var items = ImmutableList<T>.Empty;
+
+			await using var reader = await cmd.ExecuteReaderAsync();
+
+			while (await reader.ReadAsync()) {
+				items = items.Add(readItem(reader));
+			}
+
+			return items;
+		}
+
+		public async ValueTask DisposeAsync() {
+			await cmd.DisposeAsync();
+		}
+	}
+
+	public async IAsyncEnumerable<Message> Get(MessageFilter? filter) {
+		await using var conn = await pool.Take();
+
+		const string AttachmentSql =
+			"""
+			SELECT attachment_id, name, type, normalized_url, download_url, size, width, height
+			FROM attachments
+			WHERE message_id = :message_id
+			""";
+
+		await using var attachmentCmd = new MessageToManyCommand<Attachment>(conn, AttachmentSql, static reader => new Attachment {
+			Id = reader.GetUint64(0),
+			Name = reader.GetString(1),
+			Type = reader.IsDBNull(2) ? null : reader.GetString(2),
+			NormalizedUrl = reader.GetString(3),
+			DownloadUrl = reader.GetString(4),
+			Size = reader.GetUint64(5),
+			Width = reader.IsDBNull(6) ? null : reader.GetInt32(6),
+			Height = reader.IsDBNull(7) ? null : reader.GetInt32(7),
+		});
+
+		const string EmbedSql =
+			"""
+			SELECT json
+			FROM embeds
+			WHERE message_id = :message_id
+			""";
+
+		await using var embedCmd = new MessageToManyCommand<Embed>(conn, EmbedSql, static reader => new Embed {
+			Json = reader.GetString(0)
+		});
+
+		const string ReactionSql =
+			"""
+			SELECT emoji_id, emoji_name, emoji_flags, count
+			FROM reactions
+			WHERE message_id = :message_id
+			""";
+
+		await using var reactionsCmd = new MessageToManyCommand<Reaction>(conn, ReactionSql, static reader => new Reaction {
+			EmojiId = reader.IsDBNull(0) ? null : reader.GetUint64(0),
+			EmojiName = reader.IsDBNull(1) ? null : reader.GetString(1),
+			EmojiFlags = (EmojiFlags) reader.GetInt16(2),
+			Count = reader.GetInt32(3),
+		});
+
+		await using var messageCmd = conn.Command(
+			$"""
+			 SELECT m.message_id, m.sender_id, m.channel_id, m.text, m.timestamp, et.edit_timestamp, rt.replied_to_id
+			 FROM messages m
+			 LEFT JOIN edit_timestamps et ON m.message_id = et.message_id
+			 LEFT JOIN replied_to rt ON m.message_id = rt.message_id
+			 {filter.GenerateConditions("m").BuildWhereClause()}
+			 """
+		);
+
+		await using var reader = await messageCmd.ExecuteReaderAsync();
+
+		while (await reader.ReadAsync()) {
+			ulong messageId = reader.GetUint64(0);
+
+			yield return new Message {
+				Id = messageId,
+				Sender = reader.GetUint64(1),
+				Channel = reader.GetUint64(2),
+				Text = reader.GetString(3),
+				Timestamp = reader.GetInt64(4),
+				EditTimestamp = reader.IsDBNull(5) ? null : reader.GetInt64(5),
+				RepliedToId = reader.IsDBNull(6) ? null : reader.GetUint64(6),
+				Attachments = await attachmentCmd.GetItems(messageId),
+				Embeds = await embedCmd.GetItems(messageId),
+				Reactions = await reactionsCmd.GetItems(messageId)
+			};
+		}
+	}
+
+	public async IAsyncEnumerable<ulong> GetIds(MessageFilter? filter) {
+		await using var conn = await pool.Take();
+		
+		await using var cmd = conn.Command("SELECT message_id FROM messages" + filter.GenerateConditions().BuildWhereClause());
+		await using var reader = await cmd.ExecuteReaderAsync();
+
+		while (await reader.ReadAsync()) {
+			yield return reader.GetUint64(0);
+		}
+	}
+
+	public async Task Remove(MessageFilter filter, FilterRemovalMode mode) {
+		await using (var conn = await pool.Take()) {
+			await conn.ExecuteAsync(
+				$"""
+				 -- noinspection SqlWithoutWhere
+				 DELETE FROM messages
+				 {filter.GenerateConditions(invert: mode == FilterRemovalMode.KeepMatching).BuildWhereClause()}
+				 """
+			);
+		}
+
+		UpdateTotalCount();
+	}
+}

app/Server/Database/Sqlite/Repositories/SqliteServerRepository.cs

@@ -0,0 +1,63 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+using DHT.Server.Database.Repositories;
+using DHT.Server.Database.Sqlite.Utils;
+using DHT.Utils.Logging;
+using Microsoft.Data.Sqlite;
+
+namespace DHT.Server.Database.Sqlite.Repositories;
+
+sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
+	private static readonly Log Log = Log.ForType<SqliteServerRepository>();
+	
+	private readonly SqliteConnectionPool pool;
+
+	public SqliteServerRepository(SqliteConnectionPool pool) : base(Log) {
+		this.pool = pool;
+	}
+
+	public async Task Add(IReadOnlyList<Data.Server> servers) {
+		await using (var conn = await pool.Take()) {
+			await conn.BeginTransactionAsync();
+			
+			await using var cmd = conn.Upsert("servers", [
+				("id", SqliteType.Integer),
+				("name", SqliteType.Text),
+				("type", SqliteType.Text)
+			]);
+
+			foreach (var server in servers) {
+				cmd.Set(":id", server.Id);
+				cmd.Set(":name", server.Name);
+				cmd.Set(":type", ServerTypes.ToString(server.Type));
+				await cmd.ExecuteNonQueryAsync();
+			}
+
+			await conn.CommitTransactionAsync();
+		}
+
+		UpdateTotalCount();
+	}
+
+	public override async Task<long> Count(CancellationToken cancellationToken) {
+		await using var conn = await pool.Take();
+		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM servers", static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
+	}
+
+	public async IAsyncEnumerable<Data.Server> Get() {
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command("SELECT id, name, type FROM servers");
+		await using var reader = await cmd.ExecuteReaderAsync();
+
+		while (await reader.ReadAsync()) {
+			yield return new Data.Server {
+				Id = reader.GetUint64(0),
+				Name = reader.GetString(1),
+				Type = ServerTypes.FromString(reader.GetString(2)),
+			};
+		}
+	}
+}

app/Server/Database/Sqlite/Repositories/SqliteUserRepository.cs

@@ -0,0 +1,76 @@
+using System.Collections.Generic;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+using DHT.Server.Database.Repositories;
+using DHT.Server.Database.Sqlite.Utils;
+using DHT.Server.Download;
+using DHT.Utils.Logging;
+using Microsoft.Data.Sqlite;
+
+namespace DHT.Server.Database.Sqlite.Repositories;
+
+sealed class SqliteUserRepository : BaseSqliteRepository, IUserRepository {
+	private static readonly Log Log = Log.ForType<SqliteUserRepository>();
+	
+	private readonly SqliteConnectionPool pool;
+	private readonly SqliteDownloadRepository downloads;
+
+	public SqliteUserRepository(SqliteConnectionPool pool, SqliteDownloadRepository downloads) : base(Log) {
+		this.pool = pool;
+		this.downloads = downloads;
+	}
+
+	public async Task Add(IReadOnlyList<User> users) {
+		await using (var conn = await pool.Take()) {
+			await conn.BeginTransactionAsync();
+
+			await using var cmd = conn.Upsert("users", [
+				("id", SqliteType.Integer),
+				("name", SqliteType.Text),
+				("avatar_url", SqliteType.Text),
+				("discriminator", SqliteType.Text)
+			]);
+
+			await using var downloadCollector = new SqliteDownloadRepository.NewDownloadCollector(downloads, conn);
+			
+			foreach (var user in users) {
+				cmd.Set(":id", user.Id);
+				cmd.Set(":name", user.Name);
+				cmd.Set(":avatar_url", user.AvatarUrl);
+				cmd.Set(":discriminator", user.Discriminator);
+				await cmd.ExecuteNonQueryAsync();
+
+				if (user.AvatarUrl is {} avatarUrl) {
+					await downloadCollector.Add(DownloadLinkExtractor.FromUserAvatar(user.Id, avatarUrl));
+				}
+			}
+
+			await conn.CommitTransactionAsync();
+			downloadCollector.OnCommitted();
+		}
+
+		UpdateTotalCount();
+	}
+
+	public override async Task<long> Count(CancellationToken cancellationToken) {
+		await using var conn = await pool.Take();
+		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM users", static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
+	}
+
+	public async IAsyncEnumerable<User> Get() {
+		await using var conn = await pool.Take();
+
+		await using var cmd = conn.Command("SELECT id, name, avatar_url, discriminator FROM users");
+		await using var reader = await cmd.ExecuteReaderAsync();
+
+		while (await reader.ReadAsync()) {
+			yield return new User {
+				Id = reader.GetUint64(0),
+				Name = reader.GetString(1),
+				AvatarUrl = reader.IsDBNull(2) ? null : reader.GetString(2),
+				Discriminator = reader.IsDBNull(3) ? null : reader.GetString(3),
+			};
+		}
+	}
+}

app/Server/Database/Sqlite/Schema.cs

@@ -1,301 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Threading.Tasks;
-using DHT.Server.Database.Exceptions;
-using DHT.Server.Database.Sqlite.Utils;
-using DHT.Server.Download;
-using DHT.Utils.Logging;
-using Microsoft.Data.Sqlite;
-
-namespace DHT.Server.Database.Sqlite;
-
-sealed class Schema {
-	internal const int Version = 6;
-
-	private static readonly Log Log = Log.ForType<Schema>();
-
-	private readonly ISqliteConnection conn;
-
-	public Schema(ISqliteConnection conn) {
-		this.conn = conn;
-	}
-
-	private void Execute(string sql) {
-		conn.Command(sql).ExecuteNonQuery();
-	}
-
-	public async Task<bool> Setup(Func<Task<bool>> checkCanUpgradeSchemas) {
-		Execute(@"CREATE TABLE IF NOT EXISTS metadata (key TEXT PRIMARY KEY, value TEXT)");
-
-		var dbVersionStr = conn.SelectScalar("SELECT value FROM metadata WHERE key = 'version'");
-		if (dbVersionStr == null) {
-			InitializeSchemas();
-		}
-		else if (!int.TryParse(dbVersionStr.ToString(), out int dbVersion) || dbVersion < 1) {
-			throw new InvalidDatabaseVersionException(dbVersionStr.ToString() ?? "<null>");
-		}
-		else if (dbVersion > Version) {
-			throw new DatabaseTooNewException(dbVersion);
-		}
-		else if (dbVersion < Version) {
-			var proceed = await checkCanUpgradeSchemas();
-			if (!proceed) {
-				return false;
-			}
-
-			UpgradeSchemas(dbVersion);
-		}
-
-		return true;
-	}
-
-	private void InitializeSchemas() {
-		Execute("""
-				CREATE TABLE users (
-					id            INTEGER PRIMARY KEY NOT NULL,
-					name          TEXT NOT NULL,
-					avatar_url    TEXT,
-					discriminator TEXT
-				)
-				""");
-
-		Execute("""
-				CREATE TABLE servers (
-					id   INTEGER PRIMARY KEY NOT NULL,
-					name TEXT NOT NULL,
-					type TEXT NOT NULL
-				)
-				""");
-
-		Execute("""
-				CREATE TABLE channels (
-					id        INTEGER PRIMARY KEY NOT NULL,
-					server    INTEGER NOT NULL,
-					name      TEXT NOT NULL,
-					parent_id INTEGER,
-					position  INTEGER,
-					topic     TEXT,
-					nsfw      INTEGER
-				)
-				""");
-
-		Execute("""
-				CREATE TABLE messages (
-					message_id INTEGER PRIMARY KEY NOT NULL,
-					sender_id  INTEGER NOT NULL,
-					channel_id INTEGER NOT NULL,
-					text       TEXT NOT NULL,
-					timestamp  INTEGER NOT NULL
-				)
-				""");
-
-		Execute("""
-				CREATE TABLE attachments (
-					message_id     INTEGER NOT NULL,
-					attachment_id  INTEGER NOT NULL PRIMARY KEY NOT NULL,
-					name           TEXT NOT NULL,
-					type           TEXT,
-					normalized_url TEXT NOT NULL,
-					download_url   TEXT,
-					size           INTEGER NOT NULL,
-					width          INTEGER,
-					height         INTEGER
-				)
-				""");
-
-		Execute("""
-				CREATE TABLE embeds (
-					message_id INTEGER NOT NULL,
-					json       TEXT NOT NULL
-				)
-				""");
-
-		Execute("""
-				CREATE TABLE downloads (
-					normalized_url TEXT NOT NULL PRIMARY KEY,
-					download_url   TEXT,
-					status         INTEGER NOT NULL,
-					size           INTEGER NOT NULL,
-					blob           BLOB
-				)
-				""");
-		
-		Execute("""
-				CREATE TABLE reactions (
-					message_id  INTEGER NOT NULL,
-					emoji_id    INTEGER,
-					emoji_name  TEXT,
-					emoji_flags INTEGER NOT NULL,
-					count       INTEGER NOT NULL
-				)
-				""");
-
-		CreateMessageEditTimestampTable();
-		CreateMessageRepliedToTable();
-
-		Execute("CREATE INDEX attachments_message_ix ON attachments(message_id)");
-		Execute("CREATE INDEX embeds_message_ix ON embeds(message_id)");
-		Execute("CREATE INDEX reactions_message_ix ON reactions(message_id)");
-
-		Execute("INSERT INTO metadata (key, value) VALUES ('version', " + Version + ")");
-	}
-
-	private void CreateMessageEditTimestampTable() {
-		Execute("""
-				CREATE TABLE edit_timestamps (
-					message_id     INTEGER PRIMARY KEY NOT NULL,
-					edit_timestamp INTEGER NOT NULL
-				)
-				""");
-	}
-
-	private void CreateMessageRepliedToTable() {
-		Execute("""
-				CREATE TABLE replied_to (
-					message_id    INTEGER PRIMARY KEY NOT NULL,
-					replied_to_id INTEGER NOT NULL
-				)
-				""");
-	}
-
-	private void NormalizeAttachmentUrls() {
-		var normalizedUrls = new Dictionary<long, string>();
-
-		using (var selectCmd = conn.Command("SELECT attachment_id, url FROM attachments")) {
-			using var reader = selectCmd.ExecuteReader();
-			
-			while (reader.Read()) {
-				var attachmentId = reader.GetInt64(0);
-				var originalUrl = reader.GetString(1);
-				normalizedUrls[attachmentId] = DiscordCdn.NormalizeUrl(originalUrl);
-			}
-		}
-
-		using var tx = conn.BeginTransaction();
-		
-		using (var updateCmd = conn.Command("UPDATE attachments SET download_url = url, url = :normalized_url WHERE attachment_id = :attachment_id")) {
-			updateCmd.Parameters.Add(":attachment_id", SqliteType.Integer);
-			updateCmd.Parameters.Add(":normalized_url", SqliteType.Text);
-				
-			foreach (var (attachmentId, normalizedUrl) in normalizedUrls) {
-				updateCmd.Set(":attachment_id", attachmentId);
-				updateCmd.Set(":normalized_url", normalizedUrl);
-				updateCmd.ExecuteNonQuery();
-			}
-		}
-			
-		tx.Commit();
-	}
-
-	private void NormalizeDownloadUrls() {
-		var normalizedUrlsToOriginalUrls = new Dictionary<string, string>();
-		var duplicateUrlsToDelete = new HashSet<string>();
-
-		using (var selectCmd = conn.Command("SELECT url FROM downloads ORDER BY CASE WHEN status = 200 THEN 0 ELSE 1 END")) {
-			using var reader = selectCmd.ExecuteReader();
-
-			while (reader.Read()) {
-				var originalUrl = reader.GetString(0);
-				var normalizedUrl = DiscordCdn.NormalizeUrl(originalUrl);
-
-				if (!normalizedUrlsToOriginalUrls.TryAdd(normalizedUrl, originalUrl)) {
-					duplicateUrlsToDelete.Add(originalUrl);
-				}
-			}
-		}
-
-		using var tx = conn.BeginTransaction();
-		
-		using (var deleteCmd = conn.Delete("downloads", ("url", SqliteType.Text))) {
-			foreach (var duplicateUrl in duplicateUrlsToDelete) {
-				deleteCmd.Set(":url", duplicateUrl);
-				deleteCmd.ExecuteNonQuery();
-			}
-		}
-			
-		using (var updateCmd = conn.Command("UPDATE downloads SET download_url = :download_url, url = :normalized_url WHERE url = :download_url")) {
-			updateCmd.Parameters.Add(":normalized_url", SqliteType.Text);
-			updateCmd.Parameters.Add(":download_url", SqliteType.Text);
-				
-			foreach (var (normalizedUrl, downloadUrl) in normalizedUrlsToOriginalUrls) {
-				updateCmd.Set(":normalized_url", normalizedUrl);
-				updateCmd.Set(":download_url", downloadUrl);
-				updateCmd.ExecuteNonQuery();
-			}
-		}
-			
-		tx.Commit();
-	}
-
-	private void UpgradeSchemas(int dbVersion) {
-		var perf = Log.Start("from version " + dbVersion);
-
-		Execute("UPDATE metadata SET value = " + Version + " WHERE key = 'version'");
-
-		if (dbVersion <= 1) {
-			Execute("ALTER TABLE channels ADD parent_id INTEGER");
-			perf.Step("Upgrade to version 2");
-		}
-
-		if (dbVersion <= 2) {
-			CreateMessageEditTimestampTable();
-			CreateMessageRepliedToTable();
-
-			Execute("""
-					INSERT INTO edit_timestamps (message_id, edit_timestamp)
-					SELECT message_id, edit_timestamp
-					FROM messages
-					WHERE edit_timestamp IS NOT NULL
-					""");
-
-			Execute("""
-					INSERT INTO replied_to (message_id, replied_to_id)
-					SELECT message_id, replied_to_id
-					FROM messages
-					WHERE replied_to_id IS NOT NULL
-					""");
-
-			Execute("ALTER TABLE messages DROP COLUMN replied_to_id");
-			Execute("ALTER TABLE messages DROP COLUMN edit_timestamp");
-
-			perf.Step("Upgrade to version 3");
-
-			Execute("VACUUM");
-			perf.Step("Vacuum");
-		}
-
-		if (dbVersion <= 3) {
-			Execute("""
-					CREATE TABLE downloads (
-						url    TEXT NOT NULL PRIMARY KEY,
-						status INTEGER NOT NULL,
-						size   INTEGER NOT NULL,
-						blob   BLOB
-					)
-					""");
-			
-			perf.Step("Upgrade to version 4");
-		}
-
-		if (dbVersion <= 4) {
-			Execute("ALTER TABLE attachments ADD width INTEGER");
-			Execute("ALTER TABLE attachments ADD height INTEGER");
-			perf.Step("Upgrade to version 5");
-		}
-
-		if (dbVersion <= 5) {
-			Execute("ALTER TABLE attachments ADD download_url TEXT");
-			Execute("ALTER TABLE downloads ADD download_url TEXT");
-			
-			NormalizeAttachmentUrls();
-			NormalizeDownloadUrls();
-			
-			Execute("ALTER TABLE attachments RENAME COLUMN url TO normalized_url");
-			Execute("ALTER TABLE downloads RENAME COLUMN url TO normalized_url");
-			
-			perf.Step("Upgrade to version 6");
-		}
-
-		perf.End();
-	}
-}