Release v47.2

Closes #295

app/.editorconfig

@@ -0,0 +1,2 @@
+[*.cs]
+propertychanged.auto_notify = false

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

@@ -13,6 +13,7 @@
         <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/Dialogs/NewDatabaseSettingsDialog.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/DatabasePage.axaml" value="Desktop/Desktop.csproj" />

app/Desktop/App.axaml

@@ -51,9 +51,56 @@
 
         <Style Selector="Expander">
             <Setter Property="MinHeight" Value="40" />
+            <Setter Property="Padding" Value="12" />
             <Setter Property="HorizontalAlignment" Value="Stretch" />
         </Style>
 
+        <Style Selector="TreeViewItem:not(:empty) /template/ Panel#PART_ExpandCollapseChevronContainer">
+            <Setter Property="Cursor" Value="Hand" />
+            <Setter Property="Margin" Value="0 0 5 0" />
+        </Style>
+        <Style Selector="TreeViewItem:empty /template/ Panel#PART_ExpandCollapseChevronContainer">
+            <Setter Property="Margin" Value="10 0" />
+        </Style>
+        <Style Selector="TreeViewItem[Level=0]:empty /template/ Panel#PART_ExpandCollapseChevronContainer">
+            <Setter Property="Margin" Value="0" />
+            <Setter Property="Width" Value="0" />
+        </Style>
+        <Style Selector="TreeViewItem /template/ ToggleButton#PART_ExpandCollapseChevron">
+            <Setter Property="Width" Value="18" />
+            <Setter Property="Height" Value="32" />
+        </Style>
+        <Style Selector="TreeViewItem /template/ ToggleButton#PART_ExpandCollapseChevron > Border">
+            <Setter Property="Padding" Value="2 10 3 10" />
+        </Style>
+
+        <Style Selector="TreeView.noSelection">
+            <Style Selector="^ TreeViewItem /template/ Border#PART_LayoutRoot">
+                <Setter Property="Background" Value="{DynamicResource TreeViewItemBackground}" />
+                <Setter Property="BorderBrush" Value="{DynamicResource TreeViewItemBorderBrush}" />
+            </Style>
+            <Style Selector="^ TreeViewItem /template/ Border#PART_LayoutRoot > ContentPresenter#PART_HeaderPresenter">
+                <Setter Property="Foreground" Value="{DynamicResource TreeViewItemForeground}" />
+            </Style>
+            <Style Selector="^ TreeViewItem:disabled /template/ Border#PART_LayoutRoot">
+                <Setter Property="Background" Value="{DynamicResource TreeViewItemBackgroundDisabled}" />
+                <Setter Property="BorderBrush" Value="{DynamicResource TreeViewItemBorderBrushDisabled}" />
+            </Style>
+            <Style Selector="^ TreeViewItem:disabled /template/ Border#PART_LayoutRoot > ContentPresenter#PART_HeaderPresenter">
+                <Setter Property="Foreground" Value="{DynamicResource TreeViewItemForegroundDisabled}" />
+            </Style>
+        </Style>
+
+        <Style Selector="Panel.buttons">
+            <Setter Property="Margin" Value="0 20 0 0" />
+        </Style>
+        <Style Selector="Panel.buttons > WrapPanel">
+            <Setter Property="ItemSpacing" Value="8" />
+        </Style>
+        <Style Selector="Panel.buttons Button">
+            <Setter Property="MinWidth" Value="80" />
+        </Style>
+
     </Application.Styles>
 
     <Application.Resources>

app/Desktop/Arguments.cs

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

app/Desktop/Common/AvaloniaObsevableValueExtensions.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Utils.Observables;
+
+namespace DHT.Desktop.Common;
+
+static class AvaloniaObsevableValueExtensions {
+	public static IDisposable SubscribeLastOnUI<T>(this ObservableValue<T> observable, Action<T> action, TimeSpan delayBetweenRuns) {
+		Task Action(T value, CancellationToken cancellationToken) {
+			action(value);
+			return Task.Delay(delayBetweenRuns, cancellationToken);
+		}
+		
+		return observable.SubscribeLast(Action, TaskScheduler.FromCurrentSynchronizationContext());
+	}
+}

app/Desktop/Common/AvaloniaReflection.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections;
+using System.Reflection;
+using Avalonia.Interactivity;
+
+namespace DHT.Desktop.Common;
+
+static class AvaloniaReflection {
+	private static FieldInfo InteractiveEventHandlersField { get; } = typeof(Interactive).GetField("_eventHandlers", BindingFlags.Instance | BindingFlags.NonPublic)!;
+	
+	public static void Check() {
+		if (InteractiveEventHandlersField == null) {
+			throw new InvalidOperationException("Missing field: " + nameof(InteractiveEventHandlersField));
+		}
+		
+		if (InteractiveEventHandlersField.FieldType.ToString() != "System.Collections.Generic.Dictionary`2[Avalonia.Interactivity.RoutedEvent,System.Collections.Generic.List`1[Avalonia.Interactivity.Interactive+EventSubscription]]") {
+			throw new InvalidOperationException("Invalid field type: " + nameof(InteractiveEventHandlersField) + " = " + InteractiveEventHandlersField.FieldType);
+		}
+	}
+	
+	public static IList? GetEventHandler(Interactive target, RoutedEvent routedEvent) {
+		IDictionary? eventHandlers = (IDictionary?) InteractiveEventHandlersField.GetValue(target);
+		return (IList?) eventHandlers?[routedEvent];
+	}
+}

app/Desktop/Common/DatabaseGui.cs

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

app/Desktop/Desktop.csproj

@@ -15,15 +15,18 @@
   </PropertyGroup>
   
   <ItemGroup>
-    <PackageReference Include="Avalonia" Version="11.2.3" />
+    <PackageReference Include="Avalonia" Version="11.3.0" />
-    <PackageReference Include="Avalonia.Controls.DataGrid" Version="11.2.3" />
+    <PackageReference Include="Avalonia.Controls.DataGrid" Version="11.3.0" />
     <PackageReference Include="Avalonia.Controls.ItemsRepeater" Version="11.1.5" />
-    <PackageReference Include="Avalonia.Desktop" Version="11.2.3" />
+    <PackageReference Include="Avalonia.Desktop" Version="11.3.0" />
-    <PackageReference Include="Avalonia.Diagnostics" Version="11.2.3" Condition=" '$(Configuration)' == 'Debug' " />
+    <PackageReference Include="Avalonia.Diagnostics" Version="11.3.0" Condition=" '$(Configuration)' == 'Debug' " />
-    <PackageReference Include="Avalonia.Fonts.Inter" Version="11.2.3" />
+    <PackageReference Include="Avalonia.Fonts.Inter" Version="11.3.0" />
-    <PackageReference Include="Avalonia.ReactiveUI" Version="11.2.3" />
+    <PackageReference Include="Avalonia.ReactiveUI" Version="11.3.0" />
-    <PackageReference Include="Avalonia.Themes.Fluent" Version="11.2.3" />
+    <PackageReference Include="Avalonia.Themes.Fluent" Version="11.3.0" />
-    <PackageReference Include="CommunityToolkit.Mvvm" Version="999.0.0-build.0.g0d941a6a62" />
+    <PackageReference Include="PropertyChanged.SourceGenerator" Version="1.1.1">
+      <PrivateAssets>all</PrivateAssets>
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+    </PackageReference>
   </ItemGroup>
   
   <ItemGroup>

app/Desktop/Dialogs/CheckBox/CheckBoxDialog.axaml

@@ -8,7 +8,8 @@
         x:DataType="namespace:CheckBoxDialogModel"
         Title="{Binding Title}"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
-        Width="500" SizeToContent="Height" CanResize="False"
+        MinWidth="425" MinHeight="200"
+        Width="500" Height="395" CanResize="True"
         WindowStartupLocation="CenterOwner">
 
     <Window.DataContext>
@@ -16,47 +17,35 @@
     </Window.DataContext>
 
     <Window.Styles>
-        <Style Selector="Panel.buttons">
+        <Style Selector="TreeViewItem">
-            <Setter Property="Margin" Value="0 20 0 0" />
+            <Setter Property="IsExpanded" Value="True" />
-        </Style>
-        <Style Selector="Panel.buttons > WrapPanel.right">
-            <Setter Property="HorizontalAlignment" Value="Right" />
-        </Style>
-        <Style Selector="Panel.buttons Button">
-            <Setter Property="MinWidth" Value="80" />
-        </Style>
-        <Style Selector="Panel.buttons > WrapPanel.left Button">
-            <Setter Property="Margin" Value="0 0 8 0" />
-        </Style>
-        <Style Selector="Panel.buttons > WrapPanel.right Button">
-            <Setter Property="Margin" Value="8 0 0 0" />
         </Style>
     </Window.Styles>
 
-    <StackPanel Margin="20">
+    <DockPanel Margin="20 17 20 20">
-        <ScrollViewer MaxHeight="400">
+        <Panel Classes="buttons" DockPanel.Dock="Bottom">
-            <ItemsRepeater ItemsSource="{Binding Items}">
+            <WrapPanel>
-                <ItemsRepeater.ItemTemplate>
+                <Button Command="{Binding SelectAll}" IsEnabled="{Binding !AreAllSelected}">Select All</Button>
-                    <DataTemplate>
+                <Button Command="{Binding SelectNone}" IsEnabled="{Binding !AreNoneSelected}">Select None</Button>
+            </WrapPanel>
+            <WrapPanel HorizontalAlignment="Right">
+                <Button Click="ClickOk">OK</Button>
+                <Button Click="ClickCancel">Cancel</Button>
+            </WrapPanel>
+        </Panel>
+        <ScrollViewer DockPanel.Dock="Top">
+            <TreeView Name="TreeView" Classes="noSelection" ItemsSource="{Binding RootItems}" ContainerPrepared="TreeViewOnContainerPrepared">
+                <TreeView.ItemTemplate>
+                    <TreeDataTemplate ItemsSource="{Binding Children}">
                         <CheckBox IsChecked="{Binding IsChecked}">
                             <Label>
                                 <TextBlock Text="{Binding Title}" TextWrapping="Wrap" />
                             </Label>
                         </CheckBox>
-                    </DataTemplate>
+                    </TreeDataTemplate>
-                </ItemsRepeater.ItemTemplate>
+                </TreeView.ItemTemplate>
-            </ItemsRepeater>
+            </TreeView>
         </ScrollViewer>
-        <Panel Classes="buttons">
+    </DockPanel>
-            <WrapPanel Classes="left">
-                <Button Command="{Binding SelectAll}" IsEnabled="{Binding !AreAllSelected}">Select All</Button>
-                <Button Command="{Binding SelectNone}" IsEnabled="{Binding !AreNoneSelected}">Select None</Button>
-            </WrapPanel>
-            <WrapPanel Classes="right">
-                <Button Click="ClickOk">OK</Button>
-                <Button Click="ClickCancel">Cancel</Button>
-            </WrapPanel>
-        </Panel>
-    </StackPanel>
 
 </Window>

app/Desktop/Dialogs/CheckBox/CheckBoxDialog.axaml.cs

@@ -1,6 +1,9 @@
 using System.Diagnostics.CodeAnalysis;
 using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Input;
 using Avalonia.Interactivity;
+using DHT.Desktop.Common;
 using DHT.Desktop.Dialogs.Message;
 
 namespace DHT.Desktop.Dialogs.CheckBox;
@@ -11,6 +14,36 @@ public sealed partial class CheckBoxDialog : Window {
 		InitializeComponent();
 	}
 	
+	private void TreeViewOnContainerPrepared(object? sender, ContainerPreparedEventArgs e) {
+		foreach (object? item in TreeView.Items) {
+			if (item != null && TreeView.ContainerFromItem(item) is TreeViewItem treeViewItem) {
+				treeViewItem.TemplateApplied += TreeViewItemOnTemplateApplied;
+				treeViewItem.GotFocus += TreeViewItemOnGotFocus;
+				treeViewItem.KeyDown += TreeViewItemOnKeyDown;
+			}
+		}
+	}
+	
+	private void TreeViewItemOnTemplateApplied(object? sender, TemplateAppliedEventArgs e) {
+		if (sender is TreeViewItem { HeaderPresenter: Interactive headerPresenter } ) {
+			// Removes support for double-clicking to expand.
+			AvaloniaReflection.GetEventHandler(headerPresenter, DoubleTappedEvent)?.Clear();
+		}
+	}
+	
+	private void TreeViewItemOnGotFocus(object? sender, GotFocusEventArgs e) {
+		if (e.NavigationMethod == NavigationMethod.Tab && sender is TreeViewItem treeViewItem && TreeView.SelectedItem == null) {
+			TreeView.SelectedItem = TreeView.ItemFromContainer(treeViewItem);
+		}
+	}
+	
+	private void TreeViewItemOnKeyDown(object? sender, KeyEventArgs e) {
+		if (e.Key == Key.Space && TreeView.SelectedItem is ICheckBoxItem item) {
+			item.IsChecked = item.IsChecked == false;
+			e.Handled = true;
+		}
+	}
+	
 	public void ClickOk(object? sender, RoutedEventArgs e) {
 		Close(DialogResult.OkCancel.Ok);
 	}

app/Desktop/Dialogs/CheckBox/CheckBoxDialogModel.cs

@@ -1,69 +1,73 @@
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.ComponentModel;
 using System.Linq;
-using CommunityToolkit.Mvvm.ComponentModel;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Dialogs.CheckBox;
 
-class CheckBoxDialogModel : ObservableObject {
+partial class CheckBoxDialogModel {
 	public string Title { get; init; } = "";
 	
-	private IReadOnlyList<CheckBoxItem> items = [];
+	private ImmutableArray<ICheckBoxItem> rootItems = [];
 	
-	public IReadOnlyList<CheckBoxItem> Items {
+	public ImmutableArray<ICheckBoxItem> RootItems {
-		get => items;
+		get => rootItems;
 		
 		protected set {
-			foreach (CheckBoxItem item in items) {
+			foreach (ICheckBoxItem item in ICheckBoxItem.GetAllRecursively(rootItems)) {
 				item.PropertyChanged -= OnItemPropertyChanged;
 			}
 			
-			items = value;
+			rootItems = value;
 			
-			foreach (CheckBoxItem item in items) {
+			foreach (ICheckBoxItem item in ICheckBoxItem.GetAllRecursively(rootItems)) {
 				item.PropertyChanged += OnItemPropertyChanged;
 			}
 		}
 	}
 	
-	private bool pauseCheckEvents = false;
+	protected IEnumerable<ICheckBoxItem> AllItems => ICheckBoxItem.GetAllRecursively(RootItems);
 	
-	public bool AreAllSelected => Items.All(static item => item.IsChecked);
+	[DependsOn(nameof(RootItems))]
-	public bool AreNoneSelected => Items.All(static item => !item.IsChecked);
+	public bool AreAllSelected => RootItems.All(static item => item.IsChecked == true);
+	
+	[DependsOn(nameof(RootItems))]
+	public bool AreNoneSelected => RootItems.All(static item => item.IsChecked == false);
+	
+	private bool pauseUpdatingBulkButtons = false;
 	
 	public void SelectAll() => SetAllChecked(true);
 	public void SelectNone() => SetAllChecked(false);
 	
 	private void SetAllChecked(bool isChecked) {
-		pauseCheckEvents = true;
+		pauseUpdatingBulkButtons = true;
 		
-		foreach (CheckBoxItem item in Items) {
+		foreach (ICheckBoxItem item in RootItems) {
 			item.IsChecked = isChecked;
 		}
 		
-		pauseCheckEvents = false;
+		pauseUpdatingBulkButtons = false;
 		UpdateBulkButtons();
 	}
 	
-	private void UpdateBulkButtons() {
-		OnPropertyChanged(nameof(AreAllSelected));
-		OnPropertyChanged(nameof(AreNoneSelected));
-	}
-	
 	private void OnItemPropertyChanged(object? sender, PropertyChangedEventArgs e) {
-		if (!pauseCheckEvents && e.PropertyName == nameof(CheckBoxItem.IsChecked)) {
+		if (e.PropertyName == nameof(ICheckBoxItem.IsChecked) && !pauseUpdatingBulkButtons) {
 			UpdateBulkButtons();
 		}
 	}
+	
+	private void UpdateBulkButtons() {
+		OnPropertyChanged(new PropertyChangedEventArgs(nameof(RootItems)));
+	}
 }
 
 sealed class CheckBoxDialogModel<T> : CheckBoxDialogModel {
-	private new IReadOnlyList<CheckBoxItem<T>> Items { get; }
+	public IEnumerable<T> SelectedValues => AllItems.OfType<ICheckBoxItem.Leaf<T>>()
+	                                                .Where(static item => item.IsChecked == true)
+	                                                .Select(static item => item.Value);
 	
-	public IEnumerable<CheckBoxItem<T>> SelectedItems => Items.Where(static item => item.IsChecked);
+	public CheckBoxDialogModel(ImmutableArray<ICheckBoxItem> items) {
-	
+		this.RootItems = items;
-	public CheckBoxDialogModel(IEnumerable<CheckBoxItem<T>> items) {
-		this.Items = new List<CheckBoxItem<T>>(items);
-		base.Items = Items;
 	}
 }

app/Desktop/Dialogs/CheckBox/CheckBoxItem.cs

@@ -1,20 +1,110 @@
-using CommunityToolkit.Mvvm.ComponentModel;
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.ComponentModel;
+using System.Linq;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Dialogs.CheckBox;
 
-partial class CheckBoxItem : ObservableObject {
+partial interface ICheckBoxItem : INotifyPropertyChanged {
-	public string Title { get; init; } = "";
+	public string Title { get; }
-	public object? Item { get; init; } = null;
+	public bool? IsChecked { get; set; }
 	
-	[ObservableProperty]
+	public ImmutableArray<ICheckBoxItem> Children { get; }
-	private bool isChecked = false;
-}
 	
-sealed class CheckBoxItem<T> : CheckBoxItem {
+	void NotifyIsCheckedChanged();
-	public new T Item { get; }
 	
-	public CheckBoxItem(T item) {
+	public static IEnumerable<ICheckBoxItem> GetAllRecursively(IEnumerable<ICheckBoxItem> items) {
-		this.Item = item;
+		Stack<ICheckBoxItem> stack = new Stack<ICheckBoxItem>(items);
-		base.Item = item;
+		
+		while (stack.TryPop(out var item)) {
+			yield return item;
+			
+			foreach (ICheckBoxItem child in item.Children) {
+				stack.Push(child);
+			}
+		}
+	}
+	
+	sealed class NonLeaf : ICheckBoxItem {
+		public string Title { get; }
+		
+		public bool? IsChecked {
+			get {
+				if (Children.Count(static child => child.IsChecked == true) == Children.Length) {
+					return true;
+				}
+				else if (Children.Count(static child => child.IsChecked == false) == Children.Length) {
+					return false;
+				}
+				else {
+					return null;
+				}
+			}
+			
+			set {
+				foreach (ICheckBoxItem child in Children) {
+					if (child is Leaf leaf) {
+						leaf.SetCheckedFromParent(value);
+					}
+					else {
+						child.IsChecked = value;
+					}
+				}
+				
+				NotifyIsCheckedChanged();
+				parent?.NotifyIsCheckedChanged();
+			}
+		}
+		
+		public ImmutableArray<ICheckBoxItem> Children { get; }
+		
+		public event PropertyChangedEventHandler? PropertyChanged;
+		
+		private readonly ICheckBoxItem? parent;
+		
+		public NonLeaf(string title, ICheckBoxItem? parent, Func<ICheckBoxItem, ImmutableArray<ICheckBoxItem>> children) {
+			this.parent = parent;
+			this.Title = title;
+			this.Children = children(this);
+		}
+		
+		public void NotifyIsCheckedChanged() {
+			PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(IsChecked)));
+		}
+	}
+	
+	partial class Leaf(string title, ICheckBoxItem? parent, bool isChecked) : ICheckBoxItem {
+		public string Title { get; } = title;
+		
+		public ImmutableArray<ICheckBoxItem> Children => ImmutableArray<ICheckBoxItem>.Empty;
+		
+		public readonly ICheckBoxItem? parent = parent;
+		
+		[Notify]
+		private bool? isChecked = isChecked;
+		
+		private bool notifyParent = true;
+		
+		public void SetCheckedFromParent(bool? isChecked) {
+			notifyParent = false;
+			IsChecked = isChecked;
+			notifyParent = true;
+		}
+		
+		private void OnIsCheckedChanged() {
+			if (notifyParent) {
+				parent?.NotifyIsCheckedChanged();
+			}
+		}
+		
+		void ICheckBoxItem.NotifyIsCheckedChanged() {
+			OnPropertyChanged(new PropertyChangedEventArgs(nameof(IsChecked)));
+		}
+	}
+	
+	sealed class Leaf<T>(string title, ICheckBoxItem? parent, T value, bool isChecked) : Leaf(title, parent, isChecked) {
+		public T Value => value;
 	}
 }

app/Desktop/Dialogs/CheckBox/CheckBoxItemList.cs

@@ -0,0 +1,46 @@
+using System.Collections.Generic;
+using System.Collections.Immutable;
+using System.Linq;
+
+namespace DHT.Desktop.Dialogs.CheckBox;
+
+sealed class CheckBoxItemList<TKey, TValue> where TKey : notnull {
+	private readonly List<INode> rootNodes = [];
+	private readonly Dictionary<TKey, List<INode>> parentNodes = [];
+	
+	public void AddParent(TKey key, string title) {
+		if (!parentNodes.ContainsKey(key)) {
+			List<INode> children = [];
+			rootNodes.Add(new INode.NonLeaf(title, children));
+			parentNodes[key] = children;
+		}
+	}
+	
+	public void Add(TValue value, string title, bool isChecked = false) {
+		rootNodes.Add(new INode.Leaf(title, value, isChecked));
+	}
+	
+	public void Add(TKey key, TValue value, string title, bool isChecked = false) {
+		parentNodes.GetValueOrDefault(key, rootNodes).Add(new INode.Leaf(title, value, isChecked));
+	}
+	
+	public ImmutableArray<ICheckBoxItem> ToCheckBoxItems() {
+		return [..rootNodes.Select(static node => node.ToCheckBoxItem(null))];
+	}
+	
+	private interface INode {
+		ICheckBoxItem ToCheckBoxItem(ICheckBoxItem? parent);
+		
+		sealed record NonLeaf(string Title, List<INode> Children) : INode {
+			public ICheckBoxItem ToCheckBoxItem(ICheckBoxItem? parent) {
+				return new ICheckBoxItem.NonLeaf(Title, parent, self => [..Children.Select(child => child.ToCheckBoxItem(self))]);
+			}
+		}
+		
+		sealed record Leaf(string Title, TValue Value, bool IsChecked) : INode {
+			public ICheckBoxItem ToCheckBoxItem(ICheckBoxItem? parent) {
+				return new ICheckBoxItem.Leaf<TValue>(Title, parent, Value, IsChecked);
+			}
+		}
+	}
+}

app/Desktop/Dialogs/File/FileDialogs.cs

@@ -8,6 +8,10 @@ using Avalonia.Platform.Storage;
 namespace DHT.Desktop.Dialogs.File;
 
 static class FileDialogs {
+	public static async Task<string[]> OpenFolders(this IStorageProvider storageProvider, FolderPickerOpenOptions options) {
+		return (await storageProvider.OpenFolderPickerAsync(options)).ToLocalPaths();
+	}
+	
 	public static async Task<string[]> OpenFiles(this IStorageProvider storageProvider, FilePickerOpenOptions options) {
 		return (await storageProvider.OpenFilePickerAsync(options)).ToLocalPaths();
 	}
@@ -26,11 +30,11 @@ static class FileDialogs {
 		return suggestedDirectory == null ? Task.FromResult<IStorageFolder?>(null) : window.StorageProvider.TryGetFolderFromPathAsync(suggestedDirectory);
 	}
 	
-	private static string ToLocalPath(this IStorageFile file) {
+	private static string ToLocalPath(this IStorageItem itme) {
-		return file.TryGetLocalPath() ?? throw new NotSupportedException("Local filesystem is not supported.");
+		return itme.TryGetLocalPath() ?? throw new NotSupportedException("Local filesystem is not supported.");
 	}
 	
-	private static string[] ToLocalPaths(this IReadOnlyList<IStorageFile> files) {
+	private static string[] ToLocalPaths(this IReadOnlyList<IStorageItem> items) {
-		return files.Select(ToLocalPath).ToArray();
+		return items.Select(ToLocalPath).ToArray();
 	}
 }

app/Desktop/Dialogs/Message/MessageDialog.axaml

@@ -20,24 +20,18 @@
             <Setter Property="FontSize" Value="15" />
             <Setter Property="TextWrapping" Value="Wrap" />
         </Style>
-        <Style Selector="WrapPanel">
-            <Setter Property="HorizontalAlignment" Value="Right" />
-            <Setter Property="Margin" Value="0 8 0 0" />
-        </Style>
-        <Style Selector="Button">
-            <Setter Property="Margin" Value="8 0 0 0" />
-            <Setter Property="MinWidth" Value="80" />
-        </Style>
     </Window.Styles>
 
     <StackPanel Margin="20">
         <TextBlock Text="{Binding Message}" />
-        <WrapPanel>
+        <Panel Classes="buttons">
+            <WrapPanel HorizontalAlignment="Right">
                 <Button Click="ClickOk" IsVisible="{Binding IsOkVisible}">OK</Button>
                 <Button Click="ClickYes" IsVisible="{Binding IsYesVisible}">Yes</Button>
                 <Button Click="ClickNo" IsVisible="{Binding IsNoVisible}">No</Button>
                 <Button Click="ClickCancel" IsVisible="{Binding IsCancelVisible}">Cancel</Button>
             </WrapPanel>
+        </Panel>
     </StackPanel>
 
 </Window>

app/Desktop/Dialogs/Progress/DelayedProgressDialog.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Threading.Tasks;
+using Avalonia.Controls;
+using Avalonia.Threading;
+
+namespace DHT.Desktop.Dialogs.Progress;
+
+static class DelayedProgressDialog {
+	public static async ValueTask Await(Func<Task> taskProvider, TimeSpan delay, Window window, string progressDialogTitle, string progressDialogDescription) {
+		Dispatcher.UIThread.VerifyAccess();
+		
+		Task task = Task.Run(taskProvider);
+		if (task.IsCompleted) {
+			return;
+		}
+		
+		// Freeze the UI thread for a short while in case the task finishes quickly.
+		_ = Task.WhenAny(Task.Delay(delay), task).GetAwaiter().GetResult();
+		
+		if (!task.IsCompleted) {
+			await ProgressDialog.ShowIndeterminate(window, progressDialogTitle, progressDialogDescription, _ => task);
+		}
+	}
+}

app/Desktop/Dialogs/Progress/IProgressCallback.cs

@@ -3,7 +3,7 @@ using System.Threading.Tasks;
 namespace DHT.Desktop.Dialogs.Progress;
 
 interface IProgressCallback {
-	Task Update(string message, int finishedItems, int totalItems);
+	Task Update(string message, long finishedItems, long totalItems);
 	Task UpdateIndeterminate(string message);
 	Task Hide();
 }

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

@@ -2,68 +2,47 @@ using System;
 using System.Diagnostics.CodeAnalysis;
 using System.Threading.Tasks;
 using Avalonia.Controls;
-using DHT.Desktop.Dialogs.Message;
-using DHT.Utils.Logging;
 
 namespace DHT.Desktop.Dialogs.Progress;
 
 [SuppressMessage("ReSharper", "MemberCanBeInternal")]
 public sealed partial class ProgressDialog : Window {
-	private static readonly Log Log = Log.ForType<ProgressDialog>();
+	private static readonly TimeSpan MinimumShowDuration = TimeSpan.FromMilliseconds(500);
 	
 	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 => await action(dialog, callbacks[0]));
-		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) {
+	internal static async Task<T> Show<T>(Window owner, string title, Func<ProgressDialog, IProgressCallback, Task<T>> 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);
+			taskCompletionSource.SetResult(await action(dialog, callbacks[0]));
-			try {
-				taskCompletionSource.SetResult(await action(dialog));
-			} catch (Exception e) {
-				taskCompletionSource.SetException(e);
-			}
 		});
 		
 		await dialog.ShowProgressDialog(owner);
 		return await taskCompletionSource.Task;
 	}
 	
+	internal static Task ShowIndeterminate(Window owner, string title, string message, Func<ProgressDialog, Task> action) {
+		return Show(owner, title, async (dialog, callback) => {
+			await callback.UpdateIndeterminate(message);
+			await action(dialog);
+		});
+	}
+	
+	internal static Task<T> ShowIndeterminate<T>(Window owner, string title, string message, Func<ProgressDialog, Task<T>> action) {
+		return Show<T>(owner, title, async (dialog, callback) => {
+			await callback.UpdateIndeterminate(message);
+			return await action(dialog);
+		});
+	}
+	
 	private bool isFinished = false;
+	private DateTime startTime = DateTime.Now;
 	private Task progressTask = Task.CompletedTask;
 	
 	public ProgressDialog() {
@@ -71,6 +50,8 @@ public sealed partial class ProgressDialog : Window {
 	}
 	
 	public void OnOpened(object? sender, EventArgs e) {
+		startTime = DateTime.Now;
+		
 		if (DataContext is ProgressDialogModel model) {
 			progressTask = Task.Run(model.StartTask);
 			progressTask.ContinueWith(OnFinished, TaskScheduler.FromCurrentSynchronizationContext());
@@ -81,18 +62,19 @@ public sealed partial class ProgressDialog : Window {
 		e.Cancel = !isFinished;
 	}
 	
-	private void OnFinished(Task task) {
+	private async Task OnFinished(Task task) {
 		isFinished = true;
+		
+		TimeSpan elapsedTime = DateTime.Now - startTime;
+		if (elapsedTime < MinimumShowDuration) {
+			await Task.Delay(MinimumShowDuration - elapsedTime);
+		}
+		
 		Close();
 	}
 	
 	public async Task ShowProgressDialog(Window owner) {
 		await ShowDialog(owner);
-		try {
 		await progressTask;
-		} catch (Exception e) {
-			Log.Error(e);
-			await Dialog.ShowOk(owner, "Unexpected Error", e.Message);
-		}
 	}
 }

app/Desktop/Dialogs/Progress/ProgressDialogModel.cs

@@ -38,7 +38,7 @@ sealed class ProgressDialogModel {
 			this.item = item;
 		}
 		
-		public async Task Update(string message, int finishedItems, int totalItems) {
+		public async Task Update(string message, long finishedItems, long totalItems) {
 			await Dispatcher.UIThread.InvokeAsync(() => {
 				item.Message = message;
 				item.Items = totalItems == 0 ? string.Empty : finishedItems.Format() + " / " + totalItems.Format();

app/Desktop/Dialogs/Progress/ProgressItem.cs

@@ -1,30 +1,23 @@
-using CommunityToolkit.Mvvm.ComponentModel;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Dialogs.Progress;
 
-sealed partial class ProgressItem : ObservableObject {
+sealed partial class ProgressItem {
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify]
-	[NotifyPropertyChangedFor(nameof(Opacity))]
-	private bool isVisible = false;
-	
-	public double Opacity => IsVisible ? 1.0 : 0.0;
-	
 	private string message = "";
 	
-	public string Message {
+	[Notify]
-		get => message;
-		set {
-			SetProperty(ref message, value);
-			IsVisible = !string.IsNullOrEmpty(value);
-		}
-	}
-	
-	[ObservableProperty]
 	private string items = "";
 	
-	[ObservableProperty]
+	[Notify]
-	private int progress = 0;
+	private long progress = 0L;
 	
-	[ObservableProperty]
+	[Notify]
 	private bool isIndeterminate;
+	
+	[DependsOn(nameof(Message))]
+	public bool IsVisible => !string.IsNullOrEmpty(Message);
+	
+	[DependsOn(nameof(IsVisible))]
+	public double Opacity => IsVisible ? 1.0 : 0.0;
 }

app/Desktop/Dialogs/TextBox/TextBoxDialog.axaml

@@ -15,19 +15,6 @@
         <namespace:TextBoxDialogModel />
     </Window.DataContext>
 
-    <Window.Styles>
-        <Style Selector="Panel.buttons">
-            <Setter Property="Margin" Value="0 20 0 0" />
-        </Style>
-        <Style Selector="Panel.buttons > WrapPanel.right">
-            <Setter Property="HorizontalAlignment" Value="Right" />
-        </Style>
-        <Style Selector="Panel.buttons Button">
-            <Setter Property="MinWidth" Value="80" />
-            <Setter Property="Margin" Value="8 0 0 0" />
-        </Style>
-    </Window.Styles>
-
     <StackPanel Margin="20">
         <ScrollViewer MaxHeight="400">
             <StackPanel Spacing="10">
@@ -47,7 +34,7 @@
             </StackPanel>
         </ScrollViewer>
         <Panel Classes="buttons">
-            <WrapPanel Classes="right">
+            <WrapPanel HorizontalAlignment="Right">
                 <Button Click="ClickOk" IsEnabled="{Binding !HasErrors}">OK</Button>
                 <Button Click="ClickCancel">Cancel</Button>
             </WrapPanel>

app/Desktop/Dialogs/TextBox/TextBoxDialogModel.cs

@@ -1,11 +1,11 @@
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
-using CommunityToolkit.Mvvm.ComponentModel;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Dialogs.TextBox;
 
-class TextBoxDialogModel : ObservableObject {
+partial class TextBoxDialogModel {
 	public string Title { get; init; } = "";
 	public string Description { get; init; } = "";
 	
@@ -27,10 +27,11 @@ class TextBoxDialogModel : ObservableObject {
 		}
 	}
 	
+	[DependsOn(nameof(Items))]
 	public bool HasErrors => Items.Any(static item => !item.IsValid);
 	
 	private void OnItemErrorsChanged(object? sender, DataErrorsChangedEventArgs e) {
-		OnPropertyChanged(nameof(HasErrors));
+		OnPropertyChanged(new PropertyChangedEventArgs(nameof(Items)));
 	}
 }
 

app/Desktop/Dialogs/TextBox/TextBoxItem.cs

@@ -1,26 +1,23 @@
 using System;
 using System.Collections;
 using System.ComponentModel;
-using CommunityToolkit.Mvvm.ComponentModel;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Dialogs.TextBox;
 
-class TextBoxItem : ObservableObject, INotifyDataErrorInfo {
+partial class TextBoxItem : INotifyDataErrorInfo {
 	public string Title { get; init; } = "";
 	public object? Item { get; init; } = null;
 	
 	public Func<string, bool> ValidityCheck { get; init; } = static _ => true;
 	public bool IsValid => ValidityCheck(Value);
 	
+	[Notify]
 	private string value = string.Empty;
 	
-	public string Value {
+	private void OnValueChanged() {
-		get => value;
-		set {
-			SetProperty(ref this.value, value);
 		ErrorsChanged?.Invoke(this, new DataErrorsChangedEventArgs(nameof(Value)));
 	}
-	}
 	
 	public IEnumerable GetErrors(string? propertyName) {
 		if (propertyName == nameof(Value) && !IsValid) {

app/Desktop/Discord/DiscordAppSettings.cs

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

app/Desktop/Main/AboutWindow.axaml

@@ -3,12 +3,12 @@
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:main="clr-namespace:DHT.Desktop.Main"
-        mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="360"
+        mc:Ignorable="d" d:DesignWidth="510" d:DesignHeight="425"
         x:Class="DHT.Desktop.Main.AboutWindow"
         x:DataType="main:AboutWindowModel"
         Title="About Discord History Tracker"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
-        Width="480" Height="360" CanResize="False"
+        Width="510" Height="425" CanResize="False"
         WindowStartupLocation="CenterOwner">
 
     <Design.DataContext>
@@ -16,16 +16,12 @@
     </Design.DataContext>
 
     <Window.Styles>
-        <Style Selector="StackPanel">
-            <Setter Property="Orientation" Value="Horizontal" />
-            <Setter Property="Spacing" Value="5" />
-        </Style>
         <Style Selector="TextBlock">
             <Setter Property="TextWrapping" Value="Wrap" />
             <Setter Property="VerticalAlignment" Value="Center" />
         </Style>
         <Style Selector="Grid > Button">
-            <Setter Property="Margin" Value="0 4" />
+            <Setter Property="Margin" Value="0 3" />
             <Setter Property="Padding" Value="8 4" />
             <Setter Property="HorizontalAlignment" Value="Stretch" />
         </Style>
@@ -33,44 +29,55 @@
 
     <StackPanel Orientation="Vertical" Margin="20" Spacing="12">
 
-        <TextBlock VerticalAlignment="Center">
+        <StackPanel Orientation="Vertical" Spacing="3">
-            Discord History Tracker was created by chylex and released under the MIT license.
+            <TextBlock TextWrapping="Wrap">Discord History Tracker was created by chylex.</TextBlock>
-        </TextBlock>
+            <TextBlock>It is available under the MIT license.</TextBlock>
-
-        <StackPanel>
-            <Button Command="{Binding ShowOfficialWebsite}">Official Website</Button>
-            <Button Command="{Binding ShowIssueTracker}">Issue Tracker</Button>
-            <Button Command="{Binding ShowSourceCode}">Source Code</Button>
         </StackPanel>
 
-        <Grid RowDefinitions="Auto,5,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto" ColumnDefinitions="175,125,*" Margin="0 10 0 0">
+        <StackPanel Orientation="Horizontal" Spacing="8">
+            <Button Command="{Binding OpenOfficialWebsite}">Official Website</Button>
+            <Button Command="{Binding OpenIssueTracker}">Issue Tracker</Button>
+            <Button Command="{Binding OpenSourceCode}">Source Code</Button>
+        </StackPanel>
+
+        <Grid RowDefinitions="Auto,5,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto" ColumnDefinitions="*,115,90" Margin="0 10 0 0">
             <TextBlock Grid.Row="0" Grid.Column="0" FontWeight="Bold">Third-Party Software</TextBlock>
             <TextBlock Grid.Row="0" Grid.Column="1" FontWeight="Bold">License</TextBlock>
             <TextBlock Grid.Row="0" Grid.Column="2" FontWeight="Bold">Link</TextBlock>
 
-            <TextBlock Grid.Row="2" Grid.Column="0">.NET 8</TextBlock>
+            <TextBlock Grid.Row="2" Grid.Column="0">.NET</TextBlock>
             <TextBlock Grid.Row="2" Grid.Column="1">MIT</TextBlock>
-            <Button Grid.Row="2" Grid.Column="2" Command="{Binding ShowLibraryNetCore}">GitHub</Button>
+            <Button Grid.Row="2" Grid.Column="2" Command="{Binding OpenThirdPartyNetCore}">GitHub</Button>
 
             <TextBlock Grid.Row="3" Grid.Column="0">Avalonia</TextBlock>
             <TextBlock Grid.Row="3" Grid.Column="1">MIT</TextBlock>
-            <Button Grid.Row="3" Grid.Column="2" Command="{Binding ShowLibraryAvalonia}">NuGet</Button>
+            <Button Grid.Row="3" Grid.Column="2" Command="{Binding OpenThirdPartyAvalonia}">GitHub</Button>
 
-            <TextBlock Grid.Row="4" Grid.Column="0">MVVM Toolkit</TextBlock>
+            <TextBlock Grid.Row="4" Grid.Column="0">Rx.NET</TextBlock>
             <TextBlock Grid.Row="4" Grid.Column="1">MIT</TextBlock>
-            <Button Grid.Row="4" Grid.Column="2" Command="{Binding ShowLibraryCommunityToolkit}">GitHub</Button>
+            <Button Grid.Row="4" Grid.Column="2" Command="{Binding OpenThirdPartyRxNet}">GitHub</Button>
 
             <TextBlock Grid.Row="5" Grid.Column="0">SQLite</TextBlock>
             <TextBlock Grid.Row="5" Grid.Column="1">Public Domain</TextBlock>
-            <Button Grid.Row="5" Grid.Column="2" Command="{Binding ShowLibrarySqlite}">Official Website</Button>
+            <Button Grid.Row="5" Grid.Column="2" Command="{Binding OpenThirdPartySqlite}">Website</Button>
 
             <TextBlock Grid.Row="6" Grid.Column="0">Microsoft.Data.Sqlite</TextBlock>
             <TextBlock Grid.Row="6" Grid.Column="1">Apache-2.0</TextBlock>
-            <Button Grid.Row="6" Grid.Column="2" Command="{Binding ShowLibrarySqliteAdoNet}">NuGet</Button>
+            <Button Grid.Row="6" Grid.Column="2" Command="{Binding OpenThirdPartyMicrosoftDataSqlite}">NuGet</Button>
 
-            <TextBlock Grid.Row="7" Grid.Column="0">Rx.NET</TextBlock>
+            <TextBlock Grid.Row="7" Grid.Column="0">PropertyChanged.SourceGenerator</TextBlock>
             <TextBlock Grid.Row="7" Grid.Column="1">MIT</TextBlock>
-            <Button Grid.Row="7" Grid.Column="2" Command="{Binding ShowLibraryRxNet}">GitHub</Button>
+            <Button Grid.Row="7" Grid.Column="2" Command="{Binding OpenThirdPartyPropertyChangedSourceGenerator}">GitHub</Button>
+        </Grid>
+
+        <Grid RowDefinitions="Auto,5,Auto,Auto,Auto,Auto,Auto,Auto,Auto,Auto" ColumnDefinitions="*,115,90" Margin="0 5 0 0">
+            <TextBlock Grid.Row="0" Grid.Column="0" FontWeight="Bold">Additional Thanks</TextBlock>
+            <TextBlock Grid.Row="0" Grid.Column="1" FontWeight="Bold">License</TextBlock>
+            <TextBlock Grid.Row="0" Grid.Column="2" FontWeight="Bold">Link</TextBlock>
+
+            <TextBlock Grid.Row="2" Grid.Column="0">BetterDiscord, for Webpack hooks</TextBlock>
+            <TextBlock Grid.Row="2" Grid.Column="1">Apache-2.0</TextBlock>
+            <Button Grid.Row="2" Grid.Column="2" Command="{Binding OpenThirdPartyBetterDiscord}">GitHub</Button>
         </Grid>
 
     </StackPanel>

app/Desktop/Main/AboutWindowModel.cs

@@ -3,39 +3,43 @@ using DHT.Desktop.Common;
 namespace DHT.Desktop.Main;
 
 sealed class AboutWindowModel {
-	public void ShowOfficialWebsite() {
+	public void OpenOfficialWebsite() {
 		SystemUtils.OpenUrl(Program.Website);
 	}
 	
-	public void ShowIssueTracker() {
+	public void OpenIssueTracker() {
 		SystemUtils.OpenUrl("https://github.com/chylex/Discord-History-Tracker/issues");
 	}
 	
-	public void ShowSourceCode() {
+	public void OpenSourceCode() {
 		SystemUtils.OpenUrl("https://github.com/chylex/Discord-History-Tracker");
 	}
 	
-	public void ShowLibraryNetCore() {
+	public void OpenThirdPartyNetCore() {
 		SystemUtils.OpenUrl("https://github.com/dotnet/core");
 	}
 	
-	public void ShowLibraryAvalonia() {
+	public void OpenThirdPartyAvalonia() {
-		SystemUtils.OpenUrl("https://www.nuget.org/packages/Avalonia");
+		SystemUtils.OpenUrl("https://github.com/AvaloniaUI/Avalonia");
 	}
 	
-	public void ShowLibraryCommunityToolkit() {
+	public void OpenThirdPartyPropertyChangedSourceGenerator() {
-		SystemUtils.OpenUrl("https://github.com/CommunityToolkit/dotnet");
+		SystemUtils.OpenUrl("https://github.com/canton7/PropertyChanged.SourceGenerator");
 	}
 	
-	public void ShowLibrarySqlite() {
+	public void OpenThirdPartySqlite() {
 		SystemUtils.OpenUrl("https://www.sqlite.org");
 	}
 	
-	public void ShowLibrarySqliteAdoNet() {
+	public void OpenThirdPartyMicrosoftDataSqlite() {
 		SystemUtils.OpenUrl("https://www.nuget.org/packages/Microsoft.Data.Sqlite");
 	}
 	
-	public void ShowLibraryRxNet() {
+	public void OpenThirdPartyRxNet() {
 		SystemUtils.OpenUrl("https://github.com/dotnet/reactive");
 	}
+	
+	public void OpenThirdPartyBetterDiscord() {
+		SystemUtils.OpenUrl("https://github.com/BetterDiscord/BetterDiscord");
+	}
 }

app/Desktop/Main/Controls/DownloadItemFilterPanel.axaml

@@ -13,12 +13,8 @@
 
     <UserControl.Styles>
         <Style Selector="WrapPanel > StackPanel">
-            <Setter Property="Margin" Value="0 20 40 0" />
             <Setter Property="Spacing" Value="4" />
         </Style>
-        <Style Selector="WrapPanel > StackPanel:nth-last-child(1)">
-            <Setter Property="Margin" Value="0 20 0 0" />
-        </Style>
         <Style Selector="Grid > Label">
             <Setter Property="VerticalAlignment" Value="Center" />
         </Style>
@@ -30,9 +26,9 @@
         </Style>
     </UserControl.Styles>
 
-    <StackPanel>
+    <StackPanel Spacing="20">
         <TextBlock Text="{Binding FilterStatisticsText}" />
-        <WrapPanel>
+        <WrapPanel ItemSpacing="40" LineSpacing="20">
             <StackPanel>
                 <CheckBox IsChecked="{Binding LimitSize}">Limit Size</CheckBox>
                 <StackPanel Orientation="Horizontal">

app/Desktop/Main/Controls/DownloadItemFilterPanelModel.cs

@@ -2,20 +2,18 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
-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.Server.Data.Settings;
 using DHT.Utils.Logging;
 using DHT.Utils.Tasks;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main.Controls;
 
-sealed partial class DownloadItemFilterPanelModel : ObservableObject, IAsyncDisposable {
+sealed partial class DownloadItemFilterPanelModel : IAsyncDisposable {
 	private static readonly Log Log = Log.ForType<DownloadItemFilterPanelModel>();
 	
 	public sealed record Unit(string Name, uint Scale);
@@ -32,15 +30,16 @@ sealed partial class DownloadItemFilterPanelModel : ObservableObject, IAsyncDisp
 		nameof(MaximumSizeUnit),
 	];
 	
-	public string FilterStatisticsText { get; private set; } = "";
+	[Notify(Setter.Private)]
+	private string filterStatisticsText = "";
 	
-	[ObservableProperty]
+	[Notify]
 	private bool limitSize = false;
 	
-	[ObservableProperty]
+	[Notify]
 	private ulong maximumSize = 0UL;
 	
-	[ObservableProperty]
+	[Notify]
 	private Unit maximumSizeUnit = AllUnits[0];
 	
 	public IEnumerable<Unit> Units => AllUnits;
@@ -48,7 +47,7 @@ sealed partial class DownloadItemFilterPanelModel : ObservableObject, IAsyncDisp
 	private readonly State state;
 	private readonly string verb;
 	
-	private readonly DelayedThrottledTask<FilterSettings> saveFilterSettingsTask;
+	private readonly ThrottledTask<FilterSettings> saveFilterSettingsTask;
 	private bool isLoadingFilterSettings;
 	
 	private readonly RestartableTask<long> downloadItemCountTask;
@@ -64,10 +63,10 @@ sealed partial class DownloadItemFilterPanelModel : ObservableObject, IAsyncDisp
 		this.state = state;
 		this.verb = verb;
 		
-		this.saveFilterSettingsTask = new DelayedThrottledTask<FilterSettings>(Log, TimeSpan.FromSeconds(5), SaveFilterSettings);
+		this.saveFilterSettingsTask = new ThrottledTask<FilterSettings>(Log, SaveFilterSettings, TimeSpan.FromSeconds(5), TaskScheduler.Default);
 		
 		this.downloadItemCountTask = new RestartableTask<long>(SetMatchingCount, TaskScheduler.FromCurrentSynchronizationContext());
-		this.downloadItemCountSubscription = state.Db.Downloads.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnDownloadItemCountChanged);
+		this.downloadItemCountSubscription = state.Db.Downloads.TotalCount.SubscribeLastOnUI(OnDownloadItemCountChanged, TimeSpan.FromMilliseconds(15));
 		
 		UpdateFilterStatistics();
 		
@@ -108,8 +107,7 @@ sealed partial class DownloadItemFilterPanelModel : ObservableObject, IAsyncDisp
 				await setter.Set(SettingsKey.DownloadsMaximumSizeUnit, settings.MaximumSizeUnit.Name);
 			});
 		} catch (Exception e) {
-			Log.Error("Could not save download filter settings");
+			Log.Error("Could not save download filter settings.", e);
-			Log.Error(e);
 		}
 	}
 	
@@ -151,9 +149,7 @@ sealed partial class DownloadItemFilterPanelModel : ObservableObject, IAsyncDisp
 	private void UpdateFilterStatisticsText() {
 		string matchingItemCountStr = matchingItemCount?.Format() ?? "(...)";
 		string totalItemCountStr = totalItemCount?.Format() ?? "(...)";
-		
 		FilterStatisticsText = verb + " " + matchingItemCountStr + " out of " + totalItemCountStr + " file" + (totalItemCount is null or 1 ? "." : "s.");
-		OnPropertyChanged(nameof(FilterStatisticsText));
 	}
 	
 	public DownloadItemFilter CreateFilter() {

app/Desktop/Main/Controls/MessageFilterPanel.axaml

@@ -13,12 +13,8 @@
 
     <UserControl.Styles>
         <Style Selector="WrapPanel > StackPanel">
-            <Setter Property="Margin" Value="0 20 40 0" />
             <Setter Property="Spacing" Value="4" />
         </Style>
-        <Style Selector="WrapPanel > StackPanel:nth-last-child(1)">
-            <Setter Property="Margin" Value="0 20 0 0" />
-        </Style>
         <Style Selector="Grid > Label">
             <Setter Property="VerticalAlignment" Value="Center" />
         </Style>
@@ -36,9 +32,9 @@
         </Style>
     </UserControl.Styles>
 
-    <StackPanel>
+    <StackPanel Spacing="20">
         <TextBlock Text="{Binding FilterStatisticsText}" />
-        <WrapPanel>
+        <WrapPanel ItemSpacing="40" LineSpacing="20">
             <StackPanel>
                 <CheckBox IsChecked="{Binding FilterByDate}">Filter by Date</CheckBox>
                 <Grid ColumnDefinitions="Auto, 4, 125" RowDefinitions="Auto, 4, Auto" Margin="4 0">

app/Desktop/Main/Controls/MessageFilterPanelModel.cs

@@ -1,13 +1,11 @@
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.ComponentModel;
+using System.Diagnostics.CodeAnalysis;
 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;
@@ -16,10 +14,11 @@ using DHT.Server;
 using DHT.Server.Data;
 using DHT.Server.Data.Filters;
 using DHT.Utils.Tasks;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main.Controls;
 
-sealed partial class MessageFilterPanelModel : ObservableObject, IDisposable {
+sealed partial class MessageFilterPanelModel : IDisposable {
 	private static readonly HashSet<string> FilterProperties = [
 		nameof(FilterByDate),
 		nameof(StartDate),
@@ -30,37 +29,38 @@ sealed partial class MessageFilterPanelModel : ObservableObject, IDisposable {
 		nameof(IncludedUsers),
 	];
 	
-	public string FilterStatisticsText { get; private set; } = "";
-	
 	public event PropertyChangedEventHandler? FilterPropertyChanged;
 	
 	public bool HasAnyFilters => FilterByDate || FilterByChannel || FilterByUser;
 	
-	[ObservableProperty]
+	[Notify]
+	private string filterStatisticsText = "";
+	
+	[Notify]
 	private bool filterByDate = false;
 	
-	[ObservableProperty]
+	[Notify]
 	private DateTime? startDate = null;
 	
-	[ObservableProperty]
+	[Notify]
 	private DateTime? endDate = null;
 	
-	[ObservableProperty]
+	[Notify]
 	private bool filterByChannel = false;
 	
-	[ObservableProperty]
+	[Notify]
 	private HashSet<ulong>? includedChannels = null;
 	
-	[ObservableProperty]
+	[Notify]
 	private bool filterByUser = false;
 	
-	[ObservableProperty]
+	[Notify]
 	private HashSet<ulong>? includedUsers = null;
 	
-	[ObservableProperty]
+	[Notify]
 	private string channelFilterLabel = "";
 	
-	[ObservableProperty]
+	[Notify]
 	private string userFilterLabel = "";
 	
 	private readonly Window window;
@@ -89,9 +89,9 @@ sealed partial class MessageFilterPanelModel : ObservableObject, IDisposable {
 		
 		this.exportedMessageCountTask = new RestartableTask<long>(SetExportedMessageCount, TaskScheduler.FromCurrentSynchronizationContext());
 		
-		this.messageCountSubscription = state.Db.Messages.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnMessageCountChanged);
+		this.messageCountSubscription = state.Db.Messages.TotalCount.SubscribeLastOnUI(OnMessageCountChanged, TimeSpan.FromMilliseconds(15));
-		this.channelCountSubscription = state.Db.Channels.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnChannelCountChanged);
+		this.channelCountSubscription = state.Db.Channels.TotalCount.SubscribeLastOnUI(OnChannelCountChanged, TimeSpan.FromMilliseconds(15));
-		this.userCountSubscription = state.Db.Users.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnUserCountChanged);
+		this.userCountSubscription = state.Db.Users.TotalCount.SubscribeLastOnUI(OnUserCountChanged, TimeSpan.FromMilliseconds(15));
 		
 		UpdateFilterStatistics();
 		UpdateChannelFilterLabel();
@@ -181,56 +181,67 @@ sealed partial class MessageFilterPanelModel : ObservableObject, IDisposable {
 	private void UpdateFilterStatisticsText() {
 		string exportedMessageCountStr = exportedMessageCount?.Format() ?? "(...)";
 		string totalMessageCountStr = totalMessageCount?.Format() ?? "(...)";
-		
 		FilterStatisticsText = verb + " " + exportedMessageCountStr + " out of " + totalMessageCountStr + " message" + (totalMessageCount is null or 1 ? "." : "s.");
-		OnPropertyChanged(nameof(FilterStatisticsText));
+	}
+	
+	[SuppressMessage("ReSharper", "NotAccessedPositionalProperty.Local")]
+	[SuppressMessage("ReSharper", "MemberCanBePrivate.Local")]
+	private readonly record struct ChannelFilterKey(byte Type, ulong? ServerId, string Title) : IComparable<ChannelFilterKey> {
+		public static ChannelFilterKey DirectMessages { get; } = new (Type: 1, ServerId: null, Title: "Direct Messages");
+		public static ChannelFilterKey GroupMessages { get; } = new (Type: 2, ServerId: null, Title: "Group Messages");
+		public static ChannelFilterKey Unknown { get; } = new (Type: 4, ServerId: null, Title: "Unknown");
+		
+		public static ChannelFilterKey For(DHT.Server.Data.Server server) {
+			return server.Type switch {
+				ServerType.Server        => new ChannelFilterKey(Type: 3, server.Id, "Server - " + server.Name),
+				ServerType.Group         => GroupMessages,
+				ServerType.DirectMessage => DirectMessages,
+				_                        => Unknown,
+			};
+		}
+		
+		public bool Equals(ChannelFilterKey other) {
+			return Type == other.Type && ServerId == other.ServerId;
+		}
+		
+		public override int GetHashCode() {
+			return HashCode.Combine(Type, ServerId);
+		}
+		
+		public int CompareTo(ChannelFilterKey other) {
+			int result = Type.CompareTo(other.Type);
+			if (result != 0) {
+				return result;
+			}
+			else {
+				return Title.CompareTo(other.Title);
+			}
+		}
 	}
 	
 	public async Task OpenChannelFilterDialog() {
-		async Task<List<CheckBoxItem<ulong>>> PrepareChannelItems(ProgressDialog dialog) {
+		async Task<ImmutableArray<ICheckBoxItem>> PrepareChannelItems(ProgressDialog dialog) {
-			var items = new List<CheckBoxItem<ulong>>();
+			CheckBoxItemList<ChannelFilterKey, ulong> items = new CheckBoxItemList<ChannelFilterKey, ulong>();
 			Dictionary<ulong, DHT.Server.Data.Server> servers = await state.Db.Servers.Get().ToDictionaryAsync(static server => server.Id);
 			
-			await foreach (Channel channel in state.Db.Channels.Get()) {
+			foreach (ChannelFilterKey channelFilterKey in servers.Values.Select(ChannelFilterKey.For).Order()) {
-				ulong channelId = channel.Id;
+				items.AddParent(channelFilterKey, channelFilterKey.Title);
-				string channelName = channel.Name;
-				
-				string title;
-				if (servers.TryGetValue(channel.Server, out var server)) {
-					var titleBuilder = new StringBuilder();
-					ServerType? serverType = server.Type;
-					
-					titleBuilder.Append('[')
-					            .Append(ServerTypes.ToString(serverType))
-					            .Append("] ");
-					
-					if (serverType == ServerType.DirectMessage) {
-						titleBuilder.Append(channelName);
-					}
-					else {
-						titleBuilder.Append(server.Name)
-						            .Append(" - ")
-						            .Append(channelName);
 			}
 			
-					title = titleBuilder.ToString();
+			await foreach (Channel channel in state.Db.Channels.Get().OrderBy(static channel => channel.Position ?? int.MinValue).ThenBy(static channel => channel.Name)) {
-				}
+				ChannelFilterKey key = servers.TryGetValue(channel.Server, out var server)
-				else {
+					                       ? ChannelFilterKey.For(server)
-					title = channelName;
+					                       : ChannelFilterKey.Unknown;
+				
+				items.Add(key, channel.Id, channel.Name, isChecked: IncludedChannels == null || IncludedChannels.Contains(channel.Id));
 			}
 			
-				items.Add(new CheckBoxItem<ulong>(channelId) {
+			return items.ToCheckBoxItems();
-					Title = title,
-					IsChecked = IncludedChannels == null || IncludedChannels.Contains(channelId),
-				});
-			}
-			
-			return items;
 		}
 		
 		const string Title = "Included Channels";
 		
-		List<CheckBoxItem<ulong>> items;
+		ImmutableArray<ICheckBoxItem> items;
 		try {
 			items = await ProgressDialog.ShowIndeterminate(window, Title, "Loading channels...", PrepareChannelItems);
 		} catch (Exception e) {
@@ -245,22 +256,27 @@ sealed partial class MessageFilterPanelModel : ObservableObject, IDisposable {
 	}
 	
 	public async Task OpenUserFilterDialog() {
-		async Task<List<CheckBoxItem<ulong>>> PrepareUserItems(ProgressDialog dialog) {
+		async Task<ImmutableArray<ICheckBoxItem>> PrepareUserItems(ProgressDialog dialog) {
-			var checkBoxItems = new List<CheckBoxItem<ulong>>();
+			CheckBoxItemList<ulong, ulong> items = new CheckBoxItemList<ulong, ulong>();
 			
-			await foreach (User user in state.Db.Users.Get()) {
+			static string GetDisplayName(User user) {
-				checkBoxItems.Add(new CheckBoxItem<ulong>(user.Id) {
+				return user.DisplayName == null ? user.Name : $"{user.DisplayName} ({user.Name})";
-					Title = user.DisplayName == null ? user.Name : $"{user.DisplayName} ({user.Name})",
-					IsChecked = IncludedUsers == null || IncludedUsers.Contains(user.Id),
-				});
 			}
 			
-			return checkBoxItems;
+			await foreach ((ulong id, string name) in state.Db.Users.Get().Select(static user => (user.Id, GetDisplayName(user))).OrderBy(static pair => pair.Item2)) {
+				items.Add(
+					value: id,
+					title: name,
+					isChecked: IncludedUsers == null || IncludedUsers.Contains(id)
+				);
+			}
+			
+			return items.ToCheckBoxItems();
 		}
 		
 		const string Title = "Included Users";
 		
-		List<CheckBoxItem<ulong>> items;
+		ImmutableArray<ICheckBoxItem> items;
 		try {
 			items = await ProgressDialog.ShowIndeterminate(window, Title, "Loading users...", PrepareUserItems);
 		} catch (Exception e) {
@@ -274,9 +290,7 @@ sealed partial class MessageFilterPanelModel : ObservableObject, IDisposable {
 		}
 	}
 	
-	private async Task<HashSet<ulong>?> OpenIdFilterDialog(string title, List<CheckBoxItem<ulong>> items) {
+	private async Task<HashSet<ulong>?> OpenIdFilterDialog(string title, ImmutableArray<ICheckBoxItem> items) {
-		items.Sort(static (item1, item2) => item1.Title.CompareTo(item2.Title));
-		
 		var model = new CheckBoxDialogModel<ulong>(items) {
 			Title = title,
 		};
@@ -284,7 +298,7 @@ sealed partial class MessageFilterPanelModel : ObservableObject, IDisposable {
 		var dialog = new CheckBoxDialog { DataContext = model };
 		var result = await dialog.ShowDialog<DialogResult.OkCancel>(window);
 		
-		return result == DialogResult.OkCancel.Ok ? model.SelectedItems.Select(static item => item.Item).ToHashSet() : null;
+		return result == DialogResult.OkCancel.Ok ? model.SelectedValues.ToHashSet() : null;
 	}
 	
 	public MessageFilter CreateFilter() {

app/Desktop/Main/Controls/ServerConfigurationPanel.axaml

@@ -22,16 +22,15 @@
         </Style>
         <Style Selector="WrapPanel > StackPanel">
             <Setter Property="Orientation" Value="Vertical" />
-            <Setter Property="Margin" Value="0 0 10 10" />
         </Style>
     </UserControl.Styles>
 
-    <StackPanel>
+    <StackPanel Spacing="10">
         <Button Command="{Binding OnClickToggleServerButton}" Content="{Binding ToggleServerButtonText}" IsEnabled="{Binding IsToggleServerButtonEnabled}" />
-        <TextBlock TextWrapping="Wrap" Margin="0 15">
+        <TextBlock TextWrapping="Wrap" Margin="0 5">
-            The following settings determine how the tracking script communicates with this application. If you change them, you will have to copy/paste the tracking script again.
+            The following settings determine how the tracking script communicates with this application. If you change them, you will have to copy/paste the tracking script or connection code again.
         </TextBlock>
-        <WrapPanel>
+        <WrapPanel ItemSpacing="10" LineSpacing="10">
             <StackPanel>
                 <Label Target="Port">Port</Label>
                 <TextBox x:Name="Port" Width="70" Text="{Binding InputPort}" />

app/Desktop/Main/Controls/ServerConfigurationPanelModel.cs

@@ -1,30 +1,30 @@
 using System;
+using System.ComponentModel;
 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;
 using DHT.Server.Service;
 using DHT.Utils.Logging;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main.Controls;
 
-sealed partial class ServerConfigurationPanelModel : ObservableObject, IDisposable {
+sealed partial class ServerConfigurationPanelModel : IDisposable {
 	private static readonly Log Log = Log.ForType<ServerConfigurationPanelModel>();
 	
-	[ObservableProperty]
+	[Notify]
-	[NotifyPropertyChangedFor(nameof(HasMadeChanges))]
 	private string inputPort;
 	
-	[ObservableProperty]
+	[Notify]
-	[NotifyPropertyChangedFor(nameof(HasMadeChanges))]
 	private string inputToken;
 	
+	[DependsOn(nameof(InputPort), nameof(InputToken))]
 	public bool HasMadeChanges => ServerConfiguration.Port.ToString() != InputPort || ServerConfiguration.Token != InputToken;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private bool isToggleServerButtonEnabled = true;
 	
 	public string ToggleServerButtonText => server.IsRunning ? "Stop Server" : "Start Server";
@@ -53,7 +53,7 @@ sealed partial class ServerConfigurationPanelModel : ObservableObject, IDisposab
 	}
 	
 	private void UpdateServerStatus() {
-		OnPropertyChanged(nameof(ToggleServerButtonText));
+		OnPropertyChanged(new PropertyChangedEventArgs(nameof(ToggleServerButtonText)));
 	}
 	
 	private async Task StartServer() {
@@ -62,7 +62,7 @@ sealed partial class ServerConfigurationPanelModel : ObservableObject, IDisposab
 		try {
 			await server.Start(ServerConfiguration.Port, ServerConfiguration.Token);
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not start internal server.", e);
 			await Dialog.ShowOk(window, "Internal Server Error", e.Message);
 		}
 		
@@ -76,7 +76,7 @@ sealed partial class ServerConfigurationPanelModel : ObservableObject, IDisposab
 		try {
 			await server.Stop();
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not stop internal server.", e);
 			await Dialog.ShowOk(window, "Internal Server Error", e.Message);
 		}
 		
@@ -106,7 +106,7 @@ sealed partial class ServerConfigurationPanelModel : ObservableObject, IDisposab
 		ServerConfiguration.Port = port;
 		ServerConfiguration.Token = inputToken;
 		
-		OnPropertyChanged(nameof(HasMadeChanges));
+		OnPropertyChanged(new PropertyChangedEventArgs(nameof(HasMadeChanges)));
 		
 		await StartServer();
 	}

app/Desktop/Main/Controls/StatusBarModel.cs

@@ -1,28 +1,27 @@
 using System;
-using System.Reactive.Linq;
-using Avalonia.ReactiveUI;
 using Avalonia.Threading;
-using CommunityToolkit.Mvvm.ComponentModel;
+using DHT.Desktop.Common;
 using DHT.Server;
 using DHT.Server.Service;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main.Controls;
 
-sealed partial class StatusBarModel : ObservableObject, IDisposable {
+sealed partial class StatusBarModel : IDisposable {
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private long? serverCount;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private long? channelCount;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private long? messageCount;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
-	[NotifyPropertyChangedFor(nameof(ServerStatusText))]
 	private ServerManager.Status serverStatus;
 	
-	public string ServerStatusText => serverStatus switch {
+	[DependsOn(nameof(ServerStatus))]
+	public string ServerStatusText => ServerStatus switch {
 		ServerManager.Status.Starting => "STARTING",
 		ServerManager.Status.Started  => "READY",
 		ServerManager.Status.Stopping => "STOPPING",
@@ -41,11 +40,11 @@ sealed partial class StatusBarModel : ObservableObject, IDisposable {
 	public StatusBarModel(State state) {
 		this.state = state;
 		
-		serverCountSubscription = state.Db.Servers.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(newServerCount => ServerCount = newServerCount);
+		serverCountSubscription = state.Db.Servers.TotalCount.SubscribeLastOnUI(newServerCount => ServerCount = newServerCount, TimeSpan.FromMilliseconds(15));
-		channelCountSubscription = state.Db.Channels.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(newChannelCount => ChannelCount = newChannelCount);
+		channelCountSubscription = state.Db.Channels.TotalCount.SubscribeLastOnUI(newChannelCount => ChannelCount = newChannelCount, TimeSpan.FromMilliseconds(15));
-		messageCountSubscription = state.Db.Messages.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(newMessageCount => MessageCount = newMessageCount);
+		messageCountSubscription = state.Db.Messages.TotalCount.SubscribeLastOnUI(newMessageCount => MessageCount = newMessageCount, TimeSpan.FromMilliseconds(15));
 		
-		state.Server.StatusChanged += OnServerStatusChanged;
+		state.Server.StatusChanged += OnStateServerStatusChanged;
 		serverStatus = state.Server.IsRunning ? ServerManager.Status.Started : ServerManager.Status.Stopped;
 	}
 	
@@ -54,10 +53,10 @@ sealed partial class StatusBarModel : ObservableObject, IDisposable {
 		channelCountSubscription.Dispose();
 		messageCountSubscription.Dispose();
 		
-		state.Server.StatusChanged -= OnServerStatusChanged;
+		state.Server.StatusChanged -= OnStateServerStatusChanged;
 	}
 	
-	private void OnServerStatusChanged(object? sender, ServerManager.Status e) {
+	private void OnStateServerStatusChanged(object? sender, ServerManager.Status e) {
 		Dispatcher.UIThread.InvokeAsync(() => ServerStatus = e);
 	}
 }

app/Desktop/Main/Dialogs/NewDatabaseSettingsDialog.axaml

@@ -0,0 +1,57 @@
+<Window xmlns="https://github.com/avaloniaui"
+        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+        xmlns:namespace="clr-namespace:DHT.Desktop.Main.Dialogs"
+        mc:Ignorable="d" d:DesignWidth="450"
+        x:Class="DHT.Desktop.Main.Dialogs.NewDatabaseSettingsDialog"
+        x:DataType="namespace:NewDatabaseSettingsDialogModel"
+        Title="New Database Settings"
+        Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
+        Closing="OnClosing"
+        Width="450" SizeToContent="Height" CanResize="False"
+        WindowStartupLocation="CenterOwner">
+
+    <Window.DataContext>
+        <namespace:NewDatabaseSettingsDialogModel />
+    </Window.DataContext>
+
+    <Window.Styles>
+        <Style Selector="Label > StackPanel">
+            <Setter Property="Margin" Value="0 4 0 0" />
+            <Setter Property="Orientation" Value="Vertical" />
+            <Setter Property="Spacing" Value="5" />
+        </Style>
+        <Style Selector="TextBlock.dim">
+            <Setter Property="Foreground" Value="DimGray" />
+            <Setter Property="FontSize" Value="13" />
+        </Style>
+    </Window.Styles>
+
+    <StackPanel Orientation="Vertical" Margin="20">
+        <StackPanel Orientation="Vertical" Spacing="15">
+            <CheckBox IsChecked="{Binding SeparateFileForDownloads}">
+                <Label>
+                    <StackPanel>
+                        <TextBlock>Use a Separate Database File for Downloads</TextBlock>
+                        <TextBlock Classes="dim">Downloaded files will be stored separately from messages. This cannot be changed later.</TextBlock>
+                    </StackPanel>
+                </Label>
+            </CheckBox>
+            <CheckBox IsChecked="{Binding DownloadsAutoStart}">
+                <Label>
+                    <StackPanel>
+                        <TextBlock>Download Files Automatically</TextBlock>
+                        <TextBlock Classes="dim">Enables automatic downloads of files hosted on Discord. This can be changed later in the Downloads tab.</TextBlock>
+                    </StackPanel>
+                </Label>
+            </CheckBox>
+        </StackPanel>
+        <Panel Classes="buttons">
+            <WrapPanel HorizontalAlignment="Right">
+                <Button Click="ClickOk">OK</Button>
+            </WrapPanel>
+        </Panel>
+    </StackPanel>
+
+</Window>

app/Desktop/Main/Dialogs/NewDatabaseSettingsDialog.axaml.cs

@@ -0,0 +1,22 @@
+using System.Diagnostics.CodeAnalysis;
+using Avalonia.Controls;
+using Avalonia.Interactivity;
+
+namespace DHT.Desktop.Main.Dialogs;
+
+[SuppressMessage("ReSharper", "MemberCanBeInternal")]
+public sealed partial class NewDatabaseSettingsDialog : Window {
+	public NewDatabaseSettingsDialog() {
+		InitializeComponent();
+	}
+	
+	private void OnClosing(object? sender, WindowClosingEventArgs e) {
+		if (!e.IsProgrammatic) {
+			e.Cancel = true;
+		}
+	}
+	
+	private void ClickOk(object? sender, RoutedEventArgs e) {
+		Close();
+	}
+}

app/Desktop/Main/Dialogs/NewDatabaseSettingsDialogModel.cs

@@ -0,0 +1,11 @@
+using PropertyChanged.SourceGenerator;
+
+namespace DHT.Desktop.Main.Dialogs;
+
+sealed partial class NewDatabaseSettingsDialogModel {
+	[Notify]
+	private bool separateFileForDownloads = true;
+	
+	[Notify]
+	private bool downloadsAutoStart = true;
+}

app/Desktop/Main/MainWindowModel.cs

@@ -3,25 +3,26 @@ 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.Dialogs.Progress;
 using DHT.Desktop.Main.Screens;
 using DHT.Desktop.Server;
 using DHT.Server;
 using DHT.Server.Database;
 using DHT.Utils.Logging;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main;
 
-sealed partial class MainWindowModel : ObservableObject, IAsyncDisposable {
+sealed partial class MainWindowModel : IAsyncDisposable {
 	private const string DefaultTitle = "Discord History Tracker";
 	
 	private static readonly Log Log = Log.ForType<MainWindowModel>();
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private string title = DefaultTitle;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private UserControl currentScreen;
 	
 	private readonly WelcomeScreen welcomeScreen;
@@ -88,14 +89,21 @@ sealed partial class MainWindowModel : ObservableObject, IAsyncDisposable {
 		try {
 			await state.Server.Start(ServerConfiguration.Port, ServerConfiguration.Token);
 		} catch (Exception ex) {
-			Log.Error(ex);
+			Log.Error("Could not start internal server.", ex);
 			await Dialog.ShowOk(window, "Internal Server Error", ex.Message);
 		}
 		
+		try {
 			mainContentScreenModel = new MainContentScreenModel(window, state);
 			mainContentScreenModel.DatabaseClosed += MainContentScreenModelOnDatabaseClosed;
-		
 			await mainContentScreenModel.Initialize();
+		} catch (Exception ex) {
+			Log.Error("Could not initialize content screen.", ex);
+			await Dialog.ShowOk(window, "Initialization Error", ex.Message);
+			await DisposeContent();
+			await DisposeState();
+			return;
+		}
 		
 		Title = Path.GetFileName(state.Db.Path) + " - " + DefaultTitle;
 		CurrentScreen = new MainContentScreen { DataContext = mainContentScreenModel };
@@ -104,32 +112,33 @@ sealed partial class MainWindowModel : ObservableObject, IAsyncDisposable {
 	}
 	
 	private async void MainContentScreenModelOnDatabaseClosed(object? sender, EventArgs e) {
+		await DisposeContent();
+		
+		Title = DefaultTitle;
+		CurrentScreen = welcomeScreen;
+		
+		await DisposeState();
+		
+		welcomeScreenModel.DatabaseSelected += OnDatabaseSelected;
+	}
+	
+	private async Task DisposeContent() {
 		if (mainContentScreenModel != null) {
 			mainContentScreenModel.DatabaseClosed -= MainContentScreenModelOnDatabaseClosed;
 			await mainContentScreenModel.DisposeAsync();
 			mainContentScreenModel = null;
 		}
-		
-		await DisposeState();
-		
-		Title = DefaultTitle;
-		CurrentScreen = welcomeScreen;
-		
-		welcomeScreenModel.DatabaseSelected += OnDatabaseSelected;
 	}
 	
 	private async Task DisposeState() {
 		if (state != null) {
-			await state.DisposeAsync();
+			await DelayedProgressDialog.Await(() => state.DisposeAsync().AsTask(), TimeSpan.FromMilliseconds(200), window, "Close Database", "Please wait for the database to close...");
 			state = null;
 		}
 	}
 	
 	public async ValueTask DisposeAsync() {
-		if (mainContentScreenModel != null) {
+		await DisposeContent();
-			await mainContentScreenModel.DisposeAsync();
-		}
-		
 		await DisposeState();
 	}
 }

app/Desktop/Main/Pages/AdvancedPage.axaml

@@ -16,11 +16,5 @@
         <Expander Header="Internal Server Configuration" IsExpanded="True">
             <controls:ServerConfigurationPanel DataContext="{Binding ServerConfigurationModel}" />
         </Expander>
-        <Expander Header="Database Tools" IsExpanded="True">
-            <StackPanel Orientation="Vertical" Spacing="10">
-                <TextBlock TextWrapping="Wrap">Recreates the database to remove any traces of deleted data, which frees up space and prevents forensic recovery.</TextBlock>
-                <Button Command="{Binding VacuumDatabase}">Vacuum Database</Button>
-            </StackPanel>
-        </Expander>
     </StackPanel>
 </UserControl>

app/Desktop/Main/Pages/AdvancedPageModel.cs

@@ -1,8 +1,5 @@
 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.Server;
 
@@ -11,26 +8,14 @@ namespace DHT.Desktop.Main.Pages;
 sealed class AdvancedPageModel : IDisposable {
 	public ServerConfigurationPanelModel ServerConfigurationModel { get; }
 	
-	private readonly Window window;
-	private readonly State state;
-	
 	[Obsolete("Designer")]
 	public AdvancedPageModel() : this(null!, State.Dummy) {}
 	
 	public AdvancedPageModel(Window window, State state) {
-		this.window = window;
-		this.state = state;
-		
 		ServerConfigurationModel = new ServerConfigurationPanelModel(window, state);
 	}
 	
 	public void Dispose() {
 		ServerConfigurationModel.Dispose();
 	}
-	
-	public async Task VacuumDatabase() {
-		const string Title = "Vacuum Database";
-		await ProgressDialog.ShowIndeterminate(window, Title, "Vacuuming database...", _ => state.Db.Vacuum());
-		await Dialog.ShowOk(window, Title, "Done.");
-	}
 }

app/Desktop/Main/Pages/DatabasePage.axaml

@@ -11,22 +11,22 @@
         <pages:DatabasePageModel />
     </Design.DataContext>
 
-    <UserControl.Styles>
-        <Style Selector="WrapPanel > Button">
-            <Setter Property="Margin" Value="0 0 10 10" />
-        </Style>
-    </UserControl.Styles>
-
     <StackPanel Spacing="10">
         <DockPanel>
             <Button Command="{Binding CloseDatabase}" DockPanel.Dock="Right">Close Database</Button>
             <TextBox Text="{Binding Db.Path}" Width="NaN" Margin="0 0 10 0" IsReadOnly="True" />
         </DockPanel>
-        <WrapPanel>
+        <WrapPanel ItemSpacing="10" LineSpacing="10">
             <Button Command="{Binding OpenDatabaseFolder}">Open Database Folder</Button>
             <Button Command="{Binding MergeWithDatabase}">Merge with Database(s)...</Button>
             <Button Command="{Binding ImportLegacyArchive}">Import Legacy Archive(s)...</Button>
         </WrapPanel>
+        <Expander Header="Advanced Tools" Margin="0 25 0 0">
+            <StackPanel Orientation="Vertical" Spacing="10">
+                <TextBlock TextWrapping="Wrap">Recreate the database to free up space after deleting data.</TextBlock>
+                <Button Command="{Binding VacuumDatabase}">Vacuum Database</Button>
+            </StackPanel>
+        </Expander>
     </StackPanel>
 
 </UserControl>

app/Desktop/Main/Pages/DatabasePageModel.cs

@@ -19,6 +19,7 @@ using DHT.Server.Data;
 using DHT.Server.Database;
 using DHT.Server.Database.Import;
 using DHT.Server.Database.Sqlite.Schema;
+using DHT.Server.Database.Sqlite.Utils;
 using DHT.Utils.Logging;
 
 namespace DHT.Desktop.Main.Pages;
@@ -54,11 +55,11 @@ sealed class DatabasePageModel {
 				break;
 			
 			case PlatformID.Unix:
-				Process.Start("xdg-open", new string[] { folder });
+				Process.Start("xdg-open", [folder]);
 				break;
 			
 			case PlatformID.MacOSX:
-				Process.Start("open", new string[] { folder });
+				Process.Start("open", [folder]);
 				break;
 			
 			default:
@@ -73,15 +74,31 @@ sealed class DatabasePageModel {
 	
 	public async Task MergeWithDatabase() {
 		string[] paths = await DatabaseGui.NewOpenDatabaseFilesDialog(window, Path.GetDirectoryName(Db.Path));
-		if (paths.Length > 0) {
+		if (paths.Length == 0) {
-			await ProgressDialog.Show(window, "Database Merge", async (dialog, callback) => await MergeWithDatabaseFromPaths(Db, paths, dialog, callback));
+			return;
-		}
 		}
 		
-	private static async Task MergeWithDatabaseFromPaths(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback) {
+		const string Title = "Database Merge";
-		var schemaUpgradeCallbacks = new SchemaUpgradeCallbacks(dialog, paths.Length);
 		
-		await PerformImport(target, paths, dialog, callback, "Database Merge", "Database Error", "database file", async path => {
+		var result = new TaskCompletionSource<ImportResult?>();
+		try {
+			var dialog = new ProgressDialog();
+			dialog.DataContext = new ProgressDialogModel(Title, async callbacks => result.SetResult(await MergeWithDatabaseFromPaths(Db, paths, dialog, callbacks)), progressItems: 2);
+			await dialog.ShowProgressDialog(window);
+		} catch (Exception e) {
+			Log.Error("Could not merge databases.", e);
+			await Dialog.ShowOk(window, Title, "Could not merge databases: " + e.Message);
+			return;
+		}
+		
+		await Dialog.ShowOk(window, Title, GetImportDialogMessage(result.Task.Result, "database file"));
+	}
+	
+	private static async Task<ImportResult?> MergeWithDatabaseFromPaths(IDatabaseFile target, string[] paths, ProgressDialog dialog, IReadOnlyList<IProgressCallback> callbacks) {
+		var schemaUpgradeCallbacks = new SchemaUpgradeCallbacks(dialog, callbacks[1], paths.Length);
+		var databaseMergeProgressCallback = new DatabaseMergeProgressCallback(callbacks[1]);
+		
+		return await PerformImport(target, paths, dialog, callbacks[0], "Database Merge", async path => {
 			IDatabaseFile? db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, dialog, schemaUpgradeCallbacks);
 			
 			if (db == null) {
@@ -89,7 +106,7 @@ sealed class DatabasePageModel {
 			}
 			
 			try {
-				await target.AddFrom(db);
+				await target.Merge(db, databaseMergeProgressCallback);
 				return true;
 			} finally {
 				await db.DisposeAsync();
@@ -97,14 +114,11 @@ sealed class DatabasePageModel {
 		});
 	}
 	
-	private sealed class SchemaUpgradeCallbacks : ISchemaUpgradeCallbacks {
+	private sealed class SchemaUpgradeCallbacks(ProgressDialog dialog, IProgressCallback callback, int total) : ISchemaUpgradeCallbacks {
-		private readonly ProgressDialog dialog;
-		private readonly int total;
 		private bool? decision;
 		
-		public SchemaUpgradeCallbacks(ProgressDialog dialog, int total) {
+		public Task<InitialDatabaseSettings?> GetInitialDatabaseSettings() {
-			this.total = total;
+			return Task.FromResult<InitialDatabaseSettings?>(null);
-			this.dialog = dialog;
 		}
 		
 		public async Task<bool> CanUpgrade() {
@@ -114,6 +128,7 @@ sealed class DatabasePageModel {
 		}
 		
 		public Task Start(int versionSteps, Func<ISchemaUpgradeCallbacks.IProgressReporter, Task> doUpgrade) {
+			callback.UpdateIndeterminate("Upgrading database...");
 			return doUpgrade(new NullReporter());
 		}
 		
@@ -132,6 +147,20 @@ sealed class DatabasePageModel {
 		}
 	}
 	
+	private sealed class DatabaseMergeProgressCallback(IProgressCallback callback) : DatabaseMerging.IProgressCallback {
+		public void OnImportingMetadata() {
+			callback.UpdateIndeterminate("Importing metadata...");
+		}
+		
+		public void OnMessagesImported(long finished, long total) {
+			callback.Update("Importing messages...", finished, total);
+		}
+		
+		public void OnDownloadsImported(long finished, long total) {
+			callback.Update("Importing downloaded files...", finished, total);
+		}
+	}
+	
 	public async Task ImportLegacyArchive() {
 		string[] paths = await window.StorageProvider.OpenFiles(new FilePickerOpenOptions {
 			Title = "Open Legacy DHT Archive",
@@ -139,15 +168,28 @@ sealed class DatabasePageModel {
 			AllowMultiple = true,
 		});
 		
-		if (paths.Length > 0) {
+		if (paths.Length == 0) {
-			await ProgressDialog.Show(window, "Legacy Archive Import", async (dialog, callback) => await ImportLegacyArchiveFromPaths(Db, paths, dialog, callback));
+			return;
-		}
 		}
 		
-	private static async Task ImportLegacyArchiveFromPaths(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback) {
+		const string Title = "Legacy Archive Import";
+		
+		ImportResult? result;
+		try {
+			result = await ProgressDialog.Show(window, Title, async (dialog, callback) => await ImportLegacyArchiveFromPaths(Db, paths, dialog, callback));
+		} catch (Exception e) {
+			Log.Error("Could not import legacy archives.", e);
+			await Dialog.ShowOk(window, Title, "Could not import legacy archives: " + e.Message);
+			return;
+		}
+		
+		await Dialog.ShowOk(window, Title, GetImportDialogMessage(result, "archive file"));
+	}
+	
+	private static async Task<ImportResult?> ImportLegacyArchiveFromPaths(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback) {
 		var fakeSnowflake = new FakeSnowflake();
 		
-		await PerformImport(target, paths, dialog, callback, "Legacy Archive Import", "Legacy Archive Error", "archive file", async path => {
+		return await PerformImport(target, paths, dialog, callback, "Legacy Archive Import", async path => {
 			await using var jsonStream = new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read);
 			
 			return await LegacyArchiveImport.Read(jsonStream, target, fakeSnowflake, async servers => {
@@ -191,7 +233,7 @@ sealed class DatabasePageModel {
 		            .ToDictionary(static item => item.Item, static item => ulong.Parse(item.Value));
 	}
 	
-	private static async Task PerformImport(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback, string neutralDialogTitle, string errorDialogTitle, string itemName, Func<string, Task<bool>> performImport) {
+	private static async Task<ImportResult?> PerformImport(IDatabaseFile target, string[] paths, ProgressDialog dialog, IProgressCallback callback, string dialogTitle, Func<string, Task<bool>> performImport) {
 		int total = paths.Length;
 		DatabaseStatistics oldStatistics = await DatabaseStatistics.Take(target);
 		
@@ -199,11 +241,11 @@ sealed class DatabasePageModel {
 		int finished = 0;
 		
 		foreach (string path in paths) {
-			await callback.Update(Path.GetFileName(path), finished, total);
+			await callback.Update("File: " + Path.GetFileName(path), finished, total);
 			++finished;
 			
 			if (!File.Exists(path)) {
-				await Dialog.ShowOk(dialog, errorDialogTitle, "File '" + Path.GetFileName(path) + "' no longer exists.");
+				await Dialog.ShowOk(dialog, dialogTitle, "File '" + Path.GetFileName(path) + "' no longer exists.");
 				continue;
 			}
 			
@@ -212,20 +254,19 @@ sealed class DatabasePageModel {
 					++successful;
 				}
 			} catch (Exception ex) {
-				Log.Error(ex);
+				Log.Error("Could not import file: " + path, ex);
-				await Dialog.ShowOk(dialog, errorDialogTitle, "File '" + Path.GetFileName(path) + "' could not be imported: " + ex.Message);
+				await Dialog.ShowOk(dialog, dialogTitle, "File '" + Path.GetFileName(path) + "' could not be imported: " + ex.Message);
 			}
 		}
 		
 		await callback.Update("Done", finished, total);
 		
 		if (successful == 0) {
-			await Dialog.ShowOk(dialog, neutralDialogTitle, "Nothing was imported.");
+			return null;
-			return;
 		}
 		
 		DatabaseStatistics newStatistics = await DatabaseStatistics.Take(target);
-		await Dialog.ShowOk(dialog, neutralDialogTitle, GetImportDialogMessage(oldStatistics, newStatistics, successful, total, itemName));
+		return new ImportResult(oldStatistics, newStatistics, successful, total);
 	}
 	
 	private sealed record DatabaseStatistics(long ServerCount, long ChannelCount, long UserCount, long MessageCount) {
@@ -239,7 +280,16 @@ sealed class DatabasePageModel {
 		}
 	}
 	
-	private static string GetImportDialogMessage(DatabaseStatistics oldStatistics, DatabaseStatistics newStatistics, int successfulItems, int totalItems, string itemName) {
+	private sealed record ImportResult(DatabaseStatistics OldStatistics, DatabaseStatistics NewStatistics, int SuccessfulItems, int TotalItems);
+	
+	private static string GetImportDialogMessage(ImportResult? result, string itemName) {
+		if (result == null) {
+			return "Nothing was imported.";
+		}
+		
+		var oldStatistics = result.OldStatistics;
+		var newStatistics = result.NewStatistics;
+		
 		long newServers = newStatistics.ServerCount - oldStatistics.ServerCount;
 		long newChannels = newStatistics.ChannelCount - oldStatistics.ChannelCount;
 		long newUsers = newStatistics.UserCount - oldStatistics.UserCount;
@@ -248,11 +298,11 @@ sealed class DatabasePageModel {
 		var message = new StringBuilder();
 		message.Append("Processed ");
 		
-		if (successfulItems == totalItems) {
+		if (result.SuccessfulItems == result.TotalItems) {
-			message.Append(successfulItems.Pluralize(itemName));
+			message.Append(result.SuccessfulItems.Pluralize(itemName));
 		}
 		else {
-			message.Append(successfulItems.Format()).Append(" out of ").Append(totalItems.Pluralize(itemName));
+			message.Append(result.SuccessfulItems.Format()).Append(" out of ").Append(result.TotalItems.Pluralize(itemName));
 		}
 		
 		message.Append(" and added:\n\n  \u2022 ");
@@ -263,4 +313,18 @@ sealed class DatabasePageModel {
 		
 		return message.ToString();
 	}
+	
+	public async Task VacuumDatabase() {
+		const string Title = "Vacuum Database";
+		
+		try {
+			await ProgressDialog.ShowIndeterminate(window, Title, "Vacuuming database...", _ => Db.Vacuum());
+		} catch (Exception e) {
+			Log.Error("Could not vacuum database.", e);
+			await Dialog.ShowOk(window, Title, "Could not vacuum database: " + e.Message);
+			return;
+		}
+		
+		await Dialog.ShowOk(window, Title, "Done.");
+	}
 }

app/Desktop/Main/Pages/DebugPage.axaml

@@ -17,27 +17,26 @@
             <Setter Property="FontSize" Value="15" />
         </Style>
         <Style Selector="Label">
-            <Setter Property="Margin" Value="0 5" />
+            <Setter Property="Margin" Value="0" />
             <Setter Property="Padding" Value="0" />
         </Style>
         <Style Selector="WrapPanel > StackPanel">
             <Setter Property="Orientation" Value="Vertical" />
-            <Setter Property="Margin" Value="0 0 10 10" />
         </Style>
     </UserControl.Styles>
 
     <StackPanel Orientation="Vertical" Spacing="10">
         <Expander Header="Generate Random Data" IsExpanded="True">
-            <WrapPanel>
+            <WrapPanel ItemSpacing="10" LineSpacing="10">
-                <StackPanel>
+                <StackPanel Spacing="8">
                     <Label Target="Channels">Channels</Label>
                     <TextBox x:Name="Channels" Width="100" Text="{Binding GenerateChannels}" />
                 </StackPanel>
-                <StackPanel>
+                <StackPanel Spacing="8">
                     <Label Target="Users">Users</Label>
                     <TextBox x:Name="Users" Width="100" Text="{Binding GenerateUsers}" />
                 </StackPanel>
-                <StackPanel>
+                <StackPanel Spacing="8">
                     <Label Target="Messages">Messages</Label>
                     <TextBox x:Name="Messages" Width="100" Text="{Binding GenerateMessages}" />
                 </StackPanel>
@@ -46,5 +45,8 @@
                 </StackPanel>
             </WrapPanel>
         </Expander>
+        <Expander Header="About" IsExpanded="True">
+            <TextBlock Text="{Binding SqliteVersion, StringFormat=Sqlite Version: {0}}" />
+        </Expander>
     </StackPanel>
 </UserControl>

app/Desktop/Main/Pages/DebugPageModel.cs

@@ -9,14 +9,18 @@ using DHT.Desktop.Dialogs.Progress;
 using DHT.Server;
 using DHT.Server.Data;
 using DHT.Server.Service;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main.Pages;
 
-sealed class DebugPageModel {
+sealed partial class DebugPageModel {
 	public string GenerateChannels { get; set; } = "0";
 	public string GenerateUsers { get; set; } = "0";
 	public string GenerateMessages { get; set; } = "0";
 	
+	[Notify(Setter.Private)]
+	private string? sqliteVersion = string.Empty;
+	
 	private readonly Window window;
 	private readonly State state;
 	
@@ -28,6 +32,10 @@ sealed class DebugPageModel {
 		this.state = state;
 	}
 	
+	public async Task Initialize() {
+		SqliteVersion = await state.Db.GetVersion() ?? "<unknown>";
+	}
+	
 	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!");
@@ -51,7 +59,7 @@ sealed class DebugPageModel {
 	
 	private async Task GenerateRandomData(int channelCount, int userCount, int messageCount, IProgressCallback callback) {
 		int batchCount = (messageCount + BatchSize - 1) / BatchSize;
-		await callback.Update("Adding messages in batches of " + BatchSize, finishedItems: 0, batchCount);
+		await callback.Update("Adding messages in batches of " + BatchSize, finishedItems: 0, totalItems: batchCount);
 		
 		var rand = new Random();
 		var server = new DHT.Server.Data.Server {
@@ -74,7 +82,7 @@ sealed class DebugPageModel {
 			Id = RandomId(rand),
 			Name = RandomName("u"),
 			DisplayName = RandomName("u"),
-			AvatarUrl = null,
+			AvatarHash = null,
 			Discriminator = rand.Next(minValue: 0, maxValue: 9999).ToString(),
 		}).ToArray();
 		
@@ -169,6 +177,8 @@ sealed class DebugPageModel {
 	public string GenerateUsers { get; set; } = "0";
 	public string GenerateMessages { get; set; } = "0";
 
+	public string SqliteVersion => string.Empty;
+	
 	public void OnClickAddRandomDataToDatabase() {}
 }
 #endif

app/Desktop/Main/Pages/DownloadsPage.axaml

@@ -13,9 +13,6 @@
     </Design.DataContext>
 
     <UserControl.Styles>
-        <Style Selector="WrapPanel > Button">
-            <Setter Property="Margin" Value="0 0 10 10" />
-        </Style>
         <Style Selector="DataGridColumnHeader">
             <Setter Property="FontWeight" Value="Medium" />
         </Style>
@@ -30,13 +27,13 @@
         </Style>
     </UserControl.Styles>
 
-    <StackPanel Orientation="Vertical">
+    <StackPanel Orientation="Vertical" Spacing="20">
-        <WrapPanel Orientation="Horizontal">
+        <WrapPanel Orientation="Horizontal" ItemSpacing="10" LineSpacing="10">
             <Button Command="{Binding OnClickToggleDownload}" Content="{Binding ToggleDownloadButtonText}" IsEnabled="{Binding IsToggleDownloadButtonEnabled}" />
-            <Button Command="{Binding OnClickRetryFailedDownloads}" IsEnabled="{Binding IsRetryFailedOnDownloadsButtonEnabled}">Retry Failed Downloads</Button>
+            <Button Command="{Binding OnClickRetryFailed}" IsEnabled="{Binding IsRetryFailedOnDownloadsButtonEnabled}">Retry Failed</Button>
-            <Button Command="{Binding OnClickDeleteOrphanedDownloads}">Delete Orphaned Downloads</Button>
+            <Button Command="{Binding OnClickDeleteOrphaned}">Delete Orphaned</Button>
+            <Button Command="{Binding OnClickExportAll}" IsEnabled="{Binding HasSuccessfulDownloads}">Export All...</Button>
         </WrapPanel>
-        <StackPanel Orientation="Vertical" Spacing="20" Margin="0 10 0 0">
         <controls:DownloadItemFilterPanel DataContext="{Binding FilterModel}" IsEnabled="{Binding !$parent[UserControl].((pages:DownloadsPageModel)DataContext).IsDownloading}" />
         <TextBlock TextWrapping="Wrap">
             Downloading state and filter settings are remembered per-database.
@@ -51,5 +48,4 @@
             </DataGrid>
         </Expander>
     </StackPanel>
-    </StackPanel>
 </UserControl>

app/Desktop/Main/Pages/DownloadsPageModel.cs

@@ -1,12 +1,12 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.ObjectModel;
-using System.Reactive.Linq;
+using System.ComponentModel;
 using System.Threading.Tasks;
 using Avalonia.Controls;
-using Avalonia.ReactiveUI;
+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;
@@ -17,29 +17,34 @@ using DHT.Server.Data.Filters;
 using DHT.Server.Data.Settings;
 using DHT.Server.Download;
 using DHT.Utils.Logging;
+using DHT.Utils.Observables;
 using DHT.Utils.Tasks;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main.Pages;
 
-sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
+sealed partial class DownloadsPageModel : IAsyncDisposable {
 	private static readonly Log Log = Log.ForType<DownloadsPageModel>();
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private bool isToggleDownloadButtonEnabled = true;
 	
+	[DependsOn(nameof(IsDownloading))]
 	public string ToggleDownloadButtonText => IsDownloading ? "Stop Downloading" : "Start Downloading";
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
-	[NotifyPropertyChangedFor(nameof(IsRetryFailedOnDownloadsButtonEnabled))]
 	private bool isRetryingFailedDownloads = false;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
-	[NotifyPropertyChangedFor(nameof(IsRetryFailedOnDownloadsButtonEnabled))]
+	private bool hasSuccessfulDownloads;
+	
+	[Notify(Setter.Private)]
 	private bool hasFailedDownloads;
 	
+	[DependsOn(nameof(IsRetryingFailedDownloads), nameof(HasFailedDownloads))]
 	public bool IsRetryFailedOnDownloadsButtonEnabled => !IsRetryingFailedDownloads && HasFailedDownloads;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private string downloadMessage = "";
 	
 	public DownloadItemFilterPanelModel FilterModel { get; }
@@ -76,8 +81,8 @@ sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
 			statisticsSkipped,
 		];
 		
-		downloadStatisticsTask = new ThrottledTask<DownloadStatusStatistics>(Log, UpdateStatistics, TaskScheduler.FromCurrentSynchronizationContext());
+		downloadStatisticsTask = new ThrottledTask<DownloadStatusStatistics>(Log, UpdateStatistics, TimeSpan.FromMilliseconds(100), TaskScheduler.FromCurrentSynchronizationContext());
-		downloadItemCountSubscription = state.Db.Downloads.TotalCount.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnDownloadCountChanged);
+		downloadItemCountSubscription = state.Db.Downloads.TotalCount.SubscribeLastOnUI(OnDownloadCountChanged, TimeSpan.FromMilliseconds(15));
 		
 		RecomputeDownloadStatistics();
 	}
@@ -86,7 +91,12 @@ sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
 		await FilterModel.Initialize();
 		
 		if (await state.Db.Settings.Get(SettingsKey.DownloadsAutoStart, defaultValue: false)) {
+			try {
 				await StartDownload();
+			} catch (Exception e) {
+				Log.Error("Could not automatically start downloads.", e);
+				await Dialog.ShowOk(window, "Database Error", "Could not automatically start downloads: " + e.Message);
+			}
 		}
 	}
 	
@@ -105,23 +115,43 @@ sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
 	
 	public async Task OnClickToggleDownload() {
 		IsToggleDownloadButtonEnabled = false;
-		
+		try {
 			if (IsDownloading) {
 				await StopDownload();
 			}
 			else {
+				try {
 					await StartDownload();
+				} catch (Exception e) {
+					Log.Error("Could not start downloads.", e);
+					await Dialog.ShowOk(window, "Database Error", "Could not start downloads: " + e.Message);
+					return;
+				}
 			}
 			
+			try {
 				await state.Db.Settings.Set(SettingsKey.DownloadsAutoStart, IsDownloading);
+			} catch (Exception e) {
+				Log.Error("Could not update auto-start setting in database.", e);
+			}
+		} finally {
 			IsToggleDownloadButtonEnabled = true;
 		}
+	}
 	
 	private async Task StartDownload() {
 		await state.Db.Downloads.MoveDownloadingItemsBackToQueue();
 		
-		IObservable<DownloadItem> finishedItems = await state.Downloader.Start(currentDownloadFilter = FilterModel.CreateFilter());
+		try {
-		finishedItemsSubscription = finishedItems.ObserveOn(AvaloniaScheduler.Instance).Subscribe(OnItemFinished);
+			currentDownloadFilter = FilterModel.CreateFilter();
+			ObservableValue<DownloadItem> finishedItems = await state.Downloader.Start(currentDownloadFilter);
+			finishedItemsSubscription = finishedItems.SubscribeLastOnUI(OnItemFinished, TimeSpan.FromMilliseconds(15));
+		} catch (Exception) {
+			finishedItemsSubscription?.Dispose();
+			finishedItemsSubscription = null;
+			currentDownloadFilter = null;
+			throw;
+		}
 		
 		OnDownloadStateChanged();
 	}
@@ -132,30 +162,29 @@ sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
 		
 		finishedItemsSubscription?.Dispose();
 		finishedItemsSubscription = null;
-		
 		currentDownloadFilter = null;
+		
 		OnDownloadStateChanged();
 	}
 	
 	private void OnDownloadStateChanged() {
 		RecomputeDownloadStatistics();
 		
-		OnPropertyChanged(nameof(ToggleDownloadButtonText));
+		OnPropertyChanged(new PropertyChangedEventArgs(nameof(IsDownloading)));
-		OnPropertyChanged(nameof(IsDownloading));
 	}
 	
 	private void OnItemFinished(DownloadItem item) {
 		RecomputeDownloadStatistics();
 	}
 	
-	public async Task OnClickRetryFailedDownloads() {
+	public async Task OnClickRetryFailed() {
 		IsRetryingFailedDownloads = true;
-		
 		try {
 			await state.Db.Downloads.RetryFailed();
 			RecomputeDownloadStatistics();
 		} catch (Exception e) {
-			Log.Error(e);
+			Log.Error("Could not retry failed downloads.", e);
+			await Dialog.ShowOk(window, "Retry Failed", "Could not retry failed downloads: " + e.Message);
 		} finally {
 			IsRetryingFailedDownloads = false;
 		}
@@ -165,20 +194,18 @@ sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
 		downloadStatisticsTask.Post(cancellationToken => state.Db.Downloads.GetStatistics(currentDownloadFilter ?? new DownloadItemFilter(), cancellationToken));
 	}
 	
-	private const string DeleteOrphanedDownloadsTitle = "Delete Orphaned Downloads";
+	public async Task OnClickDeleteOrphaned() {
+		const string Title = "Delete Orphaned Downloads";
 		
-	public async Task OnClickDeleteOrphanedDownloads() {
+		try {
-		await ProgressDialog.Show(window, DeleteOrphanedDownloadsTitle, DeleteOrphanedDownloads);
+			await ProgressDialog.Show(window, Title, async (_, callback) => {
-	}
-	
-	private async Task DeleteOrphanedDownloads(ProgressDialog dialog, IProgressCallback callback) {
 				await callback.UpdateIndeterminate("Searching for orphaned downloads...");
 				
 				HashSet<string> reachableNormalizedUrls = [];
 				HashSet<string> orphanedNormalizedUrls = [];
 				
-		await foreach (Download download in state.Db.Downloads.FindAllDownloadableUrls()) {
+				await foreach (FileUrl fileUrl in state.Db.Downloads.FindReachableFiles()) {
-			reachableNormalizedUrls.Add(download.NormalizedUrl);
+					reachableNormalizedUrls.Add(fileUrl.NormalizedUrl);
 				}
 				
 				await foreach (Download download in state.Db.Downloads.Get()) {
@@ -189,11 +216,11 @@ sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
 				}
 				
 				if (orphanedNormalizedUrls.Count == 0) {
-			await Dialog.ShowOk(window, DeleteOrphanedDownloadsTitle, "No orphaned downloads found.");
+					await Dialog.ShowOk(window, Title, "No orphaned downloads found.");
 					return;
 				}
 				
-		if (await Dialog.ShowYesNo(window, DeleteOrphanedDownloadsTitle, orphanedNormalizedUrls.Count + " orphaned download(s) will be removed from this database. This action cannot be undone. Proceed?") != DialogResult.YesNo.Yes) {
+				if (await Dialog.ShowYesNo(window, Title, orphanedNormalizedUrls.Count + " orphaned download(s) will be removed from this database. This action cannot be undone. Proceed?") != DialogResult.YesNo.Yes) {
 					return;
 				}
 				
@@ -201,15 +228,63 @@ sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
 				await state.Db.Downloads.Remove(orphanedNormalizedUrls);
 				RecomputeDownloadStatistics();
 				
-		if (await Dialog.ShowYesNo(window, DeleteOrphanedDownloadsTitle, "Orphaned downloads deleted. Vacuum database now to reclaim space?") != DialogResult.YesNo.Yes) {
+				if (await Dialog.ShowYesNo(window, Title, "Orphaned downloads deleted. Vacuum database now to reclaim space?") != DialogResult.YesNo.Yes) {
 					return;
 				}
 				
 				await callback.UpdateIndeterminate("Vacuuming database...");
 				await state.Db.Vacuum();
+			});
+		} catch (Exception e) {
+			Log.Error("Could not delete orphaned downloads.", e);
+			await Dialog.ShowOk(window, Title, "Could not delete orphaned downloads: " + e.Message);
+		}
 	}
 	
-	private void UpdateStatistics(DownloadStatusStatistics statusStatistics) {
+	public async Task OnClickExportAll() {
+		const string Title = "Export Downloaded Files";
+		
+		string[] folders = await window.StorageProvider.OpenFolders(new FolderPickerOpenOptions {
+			Title = Title,
+			AllowMultiple = false,
+		});
+		
+		if (folders.Length != 1) {
+			return;
+		}
+		
+		string folderPath = folders[0];
+		
+		DownloadExporter exporter = new DownloadExporter(state.Db, folderPath);
+		DownloadExporter.Result result;
+		try {
+			result = await ProgressDialog.Show(window, Title, async (_, callback) => {
+				await callback.UpdateIndeterminate("Exporting downloaded files...");
+				return await exporter.Export(new ExportProgressReporter(callback));
+			});
+		} catch (Exception e) {
+			Log.Error("Could not export downloaded files.", e);
+			await Dialog.ShowOk(window, Title, "Could not export downloaded files: " + e.Message);
+			return;
+		}
+		
+		string messageStart = "Exported " + result.SuccessfulCount.Pluralize("file");
+		
+		if (result.FailedCount > 0L) {
+			await Dialog.ShowOk(window, Title, messageStart + " (" + result.FailedCount.Format() + " failed).");
+		}
+		else {
+			await Dialog.ShowOk(window, Title, messageStart + ".");
+		}
+	}
+	
+	private sealed class ExportProgressReporter(IProgressCallback callback) : DownloadExporter.IProgressReporter {
+		public Task ReportProgress(long processedCount, long totalCount) {
+			return callback.Update("Exporting downloaded files...", processedCount, totalCount);
+		}
+	}
+	
+	private Task UpdateStatistics(DownloadStatusStatistics statusStatistics) {
 		statisticsPending.Items = statusStatistics.PendingCount;
 		statisticsPending.Size = statusStatistics.PendingTotalSize;
 		statisticsPending.HasFilesWithUnknownSize = statusStatistics.PendingWithUnknownSizeCount > 0;
@@ -226,24 +301,25 @@ sealed partial class DownloadsPageModel : ObservableObject, IAsyncDisposable {
 		statisticsSkipped.Size = statusStatistics.SkippedTotalSize;
 		statisticsSkipped.HasFilesWithUnknownSize = statusStatistics.SkippedWithUnknownSizeCount > 0;
 		
+		HasSuccessfulDownloads = statusStatistics.SuccessfulCount > 0;
 		HasFailedDownloads = statusStatistics.FailedCount > 0;
+		
+		return Task.CompletedTask;
 	}
 	
-	[ObservableObject]
 	public sealed partial class StatisticsRow(string state) {
 		public string State { get; } = state;
 		
-		[ObservableProperty]
+		[Notify]
 		private int items;
 		
-		[ObservableProperty]
+		[Notify]
-		[NotifyPropertyChangedFor(nameof(SizeText))]
 		private ulong? size;
 		
-		[ObservableProperty]
+		[Notify]
-		[NotifyPropertyChangedFor(nameof(SizeText))]
 		private bool hasFilesWithUnknownSize;
 		
+		[DependsOn(nameof(Size), nameof(HasFilesWithUnknownSize))]
 		public string SizeText {
 			get {
 				if (size == null) {

app/Desktop/Main/Pages/TrackingPage.axaml

@@ -11,25 +11,44 @@
         <pages:TrackingPageModel />
     </Design.DataContext>
 
-    <StackPanel Spacing="10">
+    <UserControl.Styles>
-        <TextBlock TextWrapping="Wrap">
+        <Style Selector="TextBlock">
+            <Setter Property="TextWrapping" Value="Wrap" />
+        </Style>
+    </UserControl.Styles>
+
+    <StackPanel Spacing="20">
+        <Expander Header="Method 1: Manual" IsExpanded="True">
+            <StackPanel Orientation="Vertical" Spacing="10">
+                <TextBlock>
                     <TextBlock.Text>
-                <MultiBinding StringFormat="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 {0}.">
+                        <MultiBinding StringFormat="Use {0} to open Dev Tools in your browser or the Discord app, copy the tracking script, and paste it into the console.">
                             <Binding Path="OpenDevToolsShortcutText" />
                         </MultiBinding>
                     </TextBlock.Text>
                 </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>
+                <TextBlock Margin="0 5 0 0">
+                    By default, the Discord app blocks the Dev Tools shortcut. The button below changes a hidden setting to unblock the shortcut.
+                </TextBlock>
+                <Button Command="{Binding OnClickToggleAppDevTools}" Content="{Binding ToggleAppDevToolsButtonText}" IsEnabled="{Binding IsToggleAppDevToolsButtonEnabled}" />
             </StackPanel>
-        <TextBlock TextWrapping="Wrap" Margin="0 5 0 0">
+        </Expander>
-            <TextBlock.Text>
+        <Expander Header="Method 2: Userscript" IsExpanded="True">
-                <MultiBinding StringFormat="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 {0} shortcut is enabled.">
+            <StackPanel Orientation="Vertical" Spacing="10">
-                    <Binding Path="OpenDevToolsShortcutText" />
+                <TextBlock>
-                </MultiBinding>
+                    Requires a userscript manager in your browser. The userscript adds a DHT icon next to the Help icon on Discord.
-            </TextBlock.Text>
+                    If the icon does not appear, update this app and reinstall the userscript.
                 </TextBlock>
-        <Button DockPanel.Dock="Right" Command="{Binding OnClickToggleAppDevTools}" Content="{Binding ToggleAppDevToolsButtonText}" IsEnabled="{Binding IsToggleAppDevToolsButtonEnabled}" />
+                <TextBlock>
+                    Copy the Connection Code, click the DHT icon, and paste the code into the prompt.
+                </TextBlock>
+                <WrapPanel ItemSpacing="10" LineSpacing="10">
+                    <Button Command="{Binding OnClickInstallOrUpdateUserscript}">Install or Update Userscript</Button>
+                    <Button x:Name="CopyConnectionCode" Click="CopyConnectionScriptButton_OnClick">Copy Connection Code</Button>
+                </WrapPanel>
+            </StackPanel>
+        </Expander>
     </StackPanel>
 
 </UserControl>

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

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 using System.Threading.Tasks;
 using Avalonia.Controls;
@@ -8,24 +9,36 @@ namespace DHT.Desktop.Main.Pages;
 
 [SuppressMessage("ReSharper", "MemberCanBeInternal")]
 public sealed partial class TrackingPage : UserControl {
-	private bool isCopyingScript;
+	private readonly HashSet<Button> copyingButtons = new (ReferenceEqualityComparer.Instance);
 	
 	public TrackingPage() {
 		InitializeComponent();
 	}
 	
 	public async void CopyTrackingScriptButton_OnClick(object? sender, RoutedEventArgs e) {
+		await HandleCopyButton(CopyTrackingScript, "Script Copied!", static model => model.OnClickCopyTrackingScript());
+	}
+	
+	public async void CopyConnectionScriptButton_OnClick(object? sender, RoutedEventArgs e) {
+		await HandleCopyButton(CopyConnectionCode, "Code Copied!", static model => model.OnClickCopyConnectionCode());
+	}
+	
+	private async Task HandleCopyButton(Button button, string copiedText, Func<TrackingPageModel, Task<bool>> onClick) {
 		if (DataContext is TrackingPageModel model) {
-			object? originalText = CopyTrackingScript.Content;
+			object? originalText = button.Content;
-			CopyTrackingScript.MinWidth = CopyTrackingScript.Bounds.Width;
+			button.MinWidth = button.Bounds.Width;
 			
-			if (await model.OnClickCopyTrackingScript() && !isCopyingScript) {
+			if (await onClick(model) && copyingButtons.Add(button)) {
-				isCopyingScript = true;
+				button.IsEnabled = false;
-				CopyTrackingScript.Content = "Script Copied!";
+				button.Content = copiedText;
 				
+				try {
 					await Task.Delay(TimeSpan.FromSeconds(2));
-				CopyTrackingScript.Content = originalText;
+				} finally {
-				isCopyingScript = false;
+					copyingButtons.Remove(button);
+					button.IsEnabled = true;
+					button.Content = originalText;
+				}
 			}
 		}
 	}

app/Desktop/Main/Pages/TrackingPageModel.cs

@@ -1,31 +1,32 @@
 using System;
+using System.Text.RegularExpressions;
 using System.Threading;
 using System.Threading.Tasks;
 using System.Web;
 using Avalonia.Controls;
 using Avalonia.Input.Platform;
-using CommunityToolkit.Mvvm.ComponentModel;
+using DHT.Desktop.Common;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Discord;
 using DHT.Desktop.Server;
+using DHT.Utils.Logging;
+using PropertyChanged.SourceGenerator;
 using static DHT.Desktop.Program;
 
 namespace DHT.Desktop.Main.Pages;
 
-sealed partial class TrackingPageModel : ObservableObject {
+sealed partial class TrackingPageModel {
-	[ObservableProperty(Setter = Access.Private)]
+	private static readonly Log Log = Log.ForType<TrackingPageModel>();
-	private bool isCopyTrackingScriptButtonEnabled = true;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
-	[NotifyPropertyChangedFor(nameof(ToggleAppDevToolsButtonText))]
 	private bool? areDevToolsEnabled = null;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
-	[NotifyPropertyChangedFor(nameof(ToggleAppDevToolsButtonText))]
 	private bool isToggleAppDevToolsButtonEnabled = false;
 	
 	public string OpenDevToolsShortcutText { get; } = OperatingSystem.IsMacOS() ? "Cmd+Shift+I" : "Ctrl+Shift+I";
 	
+	[DependsOn(nameof(AreDevToolsEnabled), nameof(IsToggleAppDevToolsButtonEnabled))]
 	public string ToggleAppDevToolsButtonText {
 		get {
 			if (!AreDevToolsEnabled.HasValue) {
@@ -52,32 +53,9 @@ sealed partial class TrackingPageModel : ObservableObject {
 	}
 	
 	public async Task<bool> OnClickCopyTrackingScript() {
-		IsCopyTrackingScriptButtonEnabled = false;
+		string url = ServerConfiguration.HttpHost + $"/get-tracking-script?token={HttpUtility.UrlEncode(ServerConfiguration.Token)}";
-		
-		try {
-			return await CopyTrackingScript();
-		} finally {
-			IsCopyTrackingScriptButtonEnabled = true;
-		}
-	}
-	
-	private async Task<bool> CopyTrackingScript() {
-		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);
-		
+		return await TryCopy(script, "Copy Tracking Script");
-		IClipboard? clipboard = window.Clipboard;
-		if (clipboard == null) {
-			await Dialog.ShowOk(window, "Copy Tracking Script", "Clipboard is not available on this system.");
-			return false;
-		}
-		
-		try {
-			await clipboard.SetTextAsync(script);
-			return true;
-		} catch {
-			await Dialog.ShowOk(window, "Copy Tracking Script", "An error occurred while copying to clipboard.");
-			return false;
-		}
 	}
 	
 	private async Task InitializeDevToolsToggle() {
@@ -133,4 +111,44 @@ sealed partial class TrackingPageModel : ObservableObject {
 				throw new ArgumentOutOfRangeException();
 		}
 	}
+	
+	public async Task OnClickInstallOrUpdateUserscript() {
+		try {
+			SystemUtils.OpenUrl(ServerConfiguration.HttpHost + "/get-userscript/dht.user.js");
+		} catch (Exception e) {
+			await Dialog.ShowOk(window, "Install or Update Userscript", "Could not open the browser: " + e.Message);
+		}
+	}
+	
+	[GeneratedRegex("^[a-zA-Z0-9]{1,100}$")]
+	private static partial Regex ConnectionCodeTokenRegex();
+	
+	public async Task<bool> OnClickCopyConnectionCode() {
+		const string Title = "Copy Connection Code";
+		
+		if (ConnectionCodeTokenRegex().IsMatch(ServerConfiguration.Token)) {
+			return await TryCopy(ServerConfiguration.Port + ":" + ServerConfiguration.Token, Title);
+		}
+		else {
+			await Dialog.ShowOk(window, Title, "The internal server token cannot be used to create a connection code.\n\nCheck the 'Advanced' tab and ensure the token is 1-100 characters long, and only contains plain letters and numbers.");
+			return false;
+		}
+	}
+	
+	private async Task<bool> TryCopy(string script, string errorDialogTitle) {
+		IClipboard? clipboard = window.Clipboard;
+		if (clipboard == null) {
+			await Dialog.ShowOk(window, errorDialogTitle, "Clipboard is not available on this system.");
+			return false;
+		}
+		
+		try {
+			await clipboard.SetTextAsync(script);
+			return true;
+		} catch (Exception e) {
+			Log.Error("Could not copy to clipboard.", e);
+			await Dialog.ShowOk(window, errorDialogTitle, "An error occurred while copying to clipboard.");
+			return false;
+		}
+	}
 }

app/Desktop/Main/Pages/ViewerPageModel.cs

@@ -3,7 +3,6 @@ using System.ComponentModel;
 using System.Threading.Tasks;
 using System.Web;
 using Avalonia.Controls;
-using CommunityToolkit.Mvvm.ComponentModel;
 using DHT.Desktop.Common;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Dialogs.Progress;
@@ -13,16 +12,17 @@ using DHT.Server;
 using DHT.Server.Data.Filters;
 using DHT.Server.Service.Viewer;
 using DHT.Utils.Logging;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main.Pages;
 
-sealed partial class ViewerPageModel : ObservableObject, IDisposable {
+sealed partial class ViewerPageModel : IDisposable {
 	private static readonly Log Log = Log.ForType<ViewerPageModel>();
 	
 	public bool DatabaseToolFilterModeKeep { get; set; } = true;
 	public bool DatabaseToolFilterModeRemove { get; set; } = false;
 	
-	[ObservableProperty]
+	[Notify]
 	private bool hasFilters = false;
 	
 	public MessageFilterPanelModel FilterModel { get; }
@@ -51,16 +51,16 @@ sealed partial class ViewerPageModel : ObservableObject, IDisposable {
 	
 	public async void OnClickOpenViewer() {
 		try {
-			string serverUrl = "http://127.0.0.1:" + ServerConfiguration.Port;
 			string serverToken = ServerConfiguration.Token;
 			string sessionId = state.ViewerSessions.Register(new ViewerSession(FilterModel.CreateFilter())).ToString();
-			SystemUtils.OpenUrl(serverUrl + "/viewer/?token=" + HttpUtility.UrlEncode(serverToken) + "&session=" + HttpUtility.UrlEncode(sessionId));
+			SystemUtils.OpenUrl(ServerConfiguration.HttpHost + "/viewer/?token=" + HttpUtility.UrlEncode(serverToken) + "&session=" + HttpUtility.UrlEncode(sessionId));
 		} catch (Exception e) {
 			await Dialog.ShowOk(window, "Open Viewer", "Could not open viewer: " + e.Message);
 		}
 	}
 	
 	public async Task OnClickApplyFiltersToDatabase() {
+		try {
 			MessageFilter filter = FilterModel.CreateFilter();
 			long messageCount = await ProgressDialog.ShowIndeterminate(window, "Apply Filters", "Counting matching messages...", _ => state.Db.Messages.Count(filter));
 			
@@ -74,6 +74,10 @@ sealed partial class ViewerPageModel : ObservableObject, IDisposable {
 					await ApplyFilterToDatabase(filter, FilterRemovalMode.RemoveMatching);
 				}
 			}
+		} catch (Exception e) {
+			Log.Error("Could not apply filters.", e);
+			await Dialog.ShowOk(window, "Apply Filters", "Could not apply filters: " + e.Message);
+		}
 	}
 	
 	private async Task ApplyFilterToDatabase(MessageFilter filter, FilterRemovalMode removalMode) {

app/Desktop/Main/Screens/MainContentScreenModel.cs

@@ -70,6 +70,10 @@ sealed class MainContentScreenModel : IAsyncDisposable {
 	
 	public async Task Initialize() {
 		await DownloadsPageModel.Initialize();
+		
+		#if DEBUG
+		await DebugPageModel.Initialize();
+		#endif
 	}
 	
 	public async ValueTask DisposeAsync() {

app/Desktop/Main/Screens/WelcomeScreenModel.cs

@@ -5,23 +5,24 @@ using System.Net;
 using System.Net.Http;
 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.Data.Settings;
+using DHT.Desktop.Main.Dialogs;
 using DHT.Server.Database;
 using DHT.Server.Database.Sqlite.Schema;
+using DHT.Server.Database.Sqlite.Utils;
 using DHT.Utils.Logging;
+using PropertyChanged.SourceGenerator;
 
 namespace DHT.Desktop.Main.Screens;
 
-sealed partial class WelcomeScreenModel : ObservableObject {
+sealed partial class WelcomeScreenModel {
 	private static readonly Log Log = Log.ForType<WelcomeScreenModel>();
 	
 	public string Version => Program.Version;
 	
-	[ObservableProperty(Setter = Access.Private)]
+	[Notify(Setter.Private)]
 	private bool isOpenOrCreateDatabaseButtonEnabled = true;
 	
 	public event EventHandler<IDatabaseFile>? DatabaseSelected;
@@ -52,21 +53,22 @@ sealed partial class WelcomeScreenModel : ObservableObject {
 	public async Task OpenOrCreateDatabaseFromPath(string path) {
 		dbFilePath = path;
 		
-		bool isNew = !File.Exists(path);
-		
 		IDatabaseFile? db = await DatabaseGui.TryOpenOrCreateDatabaseFromPath(path, window, new SchemaUpgradeCallbacks(window));
-		if (db == null) {
+		if (db != null) {
-			return;
-		}
-		
-		if (isNew && await Dialog.ShowYesNo(window, "Automatic Downloads", "Do you want to automatically download files hosted on Discord? You can change this later in the Downloads tab.") == DialogResult.YesNo.Yes) {
-			await db.Settings.Set(SettingsKey.DownloadsAutoStart, value: true);
-		}
-		
 			DatabaseSelected?.Invoke(this, db);
 		}
+	}
 	
 	private sealed class SchemaUpgradeCallbacks(Window window) : ISchemaUpgradeCallbacks {
+		public async Task<InitialDatabaseSettings?> GetInitialDatabaseSettings() {
+			var model = new NewDatabaseSettingsDialogModel();
+			
+			var dialog = new NewDatabaseSettingsDialog { DataContext = model };
+			await dialog.ShowDialog(window);
+			
+			return new InitialDatabaseSettings(model.SeparateFileForDownloads, model.DownloadsAutoStart);
+		}
+		
 		public async Task<bool> CanUpgrade() {
 			return DialogResult.YesNo.Yes == await DatabaseGui.ShowCanUpgradeDatabaseDialog(window);
 		}
@@ -110,7 +112,9 @@ sealed partial class WelcomeScreenModel : ObservableObject {
 	}
 	
 	public async Task CheckUpdates() {
-		var latestVersion = await ProgressDialog.ShowIndeterminate<Version?>(window, "Check Updates", "Checking for updates...", async _ => {
+		string response;
+		try {
+			response = await ProgressDialog.ShowIndeterminate<string>(window, "Check Updates", "Checking for updates...", static async _ => {
 				var client = new HttpClient(new SocketsHttpHandler {
 					AutomaticDecompression = DecompressionMethods.None,
 					AllowAutoRedirect = false,
@@ -121,27 +125,19 @@ sealed partial class WelcomeScreenModel : ObservableObject {
 				client.MaxResponseContentBufferSize = 1024;
 				client.DefaultRequestHeaders.UserAgent.ParseAdd("DiscordHistoryTracker/" + Program.Version);
 				
-			string response;
+				return await client.GetStringAsync(Program.Website + "/version");
-			try {
+			});
-				response = await client.GetStringAsync(Program.Website + "/version");
 		} catch (TaskCanceledException e) when (e.InnerException is TimeoutException) {
 			await Dialog.ShowOk(window, "Check Updates", "Request timed out.");
-				return null;
+			return;
 		} catch (Exception e) {
-				Log.Error(e);
+			Log.Error("Could not check for updates.", e);
 			await Dialog.ShowOk(window, "Check Updates", "Error checking for updates: " + e.Message);
-				return null;
+			return;
 		}
 		
 		if (!System.Version.TryParse(response, out Version? latestVersion)) {
 			await Dialog.ShowOk(window, "Check Updates", "Server returned an invalid response.");
-				return null;
-			}
-			
-			return latestVersion;
-		});
-		
-		if (latestVersion == null) {
 			return;
 		}
 		

app/Desktop/Program.cs

@@ -2,6 +2,7 @@
 using System.Globalization;
 using System.Reflection;
 using Avalonia;
+using DHT.Desktop.Common;
 using DHT.Utils.Logging;
 using DHT.Utils.Resources;
 
@@ -57,6 +58,8 @@ static class Program {
 	}
 	
 	private static AppBuilder BuildAvaloniaApp() {
+		AvaloniaReflection.Check();
+		
 		return AppBuilder.Configure<App>()
 		                 .UsePlatformDetect()
 		                 .WithInterFont()

app/Desktop/Server/ServerConfiguration.cs

@@ -5,4 +5,6 @@ namespace DHT.Desktop.Server;
 static class ServerConfiguration {
 	public static ushort Port { get; set; } = ServerUtils.FindAvailablePort(min: 50000, max: 60000);
 	public static string Token { get; set; } = ServerUtils.GenerateRandomToken(20);
+	
+	public static string HttpHost => "http://127.0.0.1:" + Port;
 }

app/Directory.Build.props

@@ -21,12 +21,13 @@
   <PropertyGroup>
     <SuppressTrimAnalysisWarnings>false</SuppressTrimAnalysisWarnings>
     <PublishTrimmed>true</PublishTrimmed>
-    <TrimMode>partial</TrimMode>
+    <TrimMode>full</TrimMode>
     <EnableUnsafeBinaryFormatterSerialization>false</EnableUnsafeBinaryFormatterSerialization>
     <EnableUnsafeUTF7Encoding>false</EnableUnsafeUTF7Encoding>
     <EventSourceSupport>false</EventSourceSupport>
     <HttpActivityPropagationSupport>false</HttpActivityPropagationSupport>
     <JsonSerializerIsReflectionEnabledByDefault>false</JsonSerializerIsReflectionEnabledByDefault>
+    <XmlResolverIsNetworkingEnabledByDefault>false</XmlResolverIsNetworkingEnabledByDefault>
   </PropertyGroup>
   
   <PropertyGroup>

app/Resources/Tracker/loader/dht.user.js

@@ -0,0 +1,273 @@
+// ==UserScript==
+// @name         Discord History Tracker
+// @license      MIT
+// @namespace    https://chylex.com
+// @homepageURL  https://dht.chylex.com/
+// @supportURL   https://github.com/chylex/Discord-History-Tracker/issues
+// @include      https://discord.com/*
+// @run-at       document-idle
+// @grant        none
+// @noframes
+// ==/UserScript==
+
+function startMutationObserver(callback) {
+	let hasDebounceStarted = false;
+	
+	function handleMutations(mutations, observer) {
+		if (hasDebounceStarted) {
+			return;
+		}
+		
+		hasDebounceStarted = true;
+		window.setTimeout(() => {
+			hasDebounceStarted = false;
+			callback(observer);
+		}, 20);
+	}
+	
+	new MutationObserver(handleMutations).observe(document.body, { childList: true, subtree: true });
+}
+
+startMutationObserver(observer => {
+	const triggerButton = installConnectDialogButton();
+	if (triggerButton === null) {
+		return;
+	}
+	
+	observer.disconnect();
+	
+	startMutationObserver(() => {
+		if (!triggerButton.isConnected) {
+			getHelpIcon()?.parentElement.parentElement.insertAdjacentElement("afterend", triggerButton);
+		}
+	});
+});
+
+function installConnectDialogButton() {
+	const helpIcon = getHelpIcon();
+	if (!helpIcon) {
+		return null;
+	}
+	
+	const helpIconWrapper = helpIcon.parentElement;
+	const helpIconLink = helpIconWrapper.parentElement;
+	
+	helpIconLink.insertAdjacentHTML("afterend", `
+<div id="dht-connector-show-dialog" role="button" class="${helpIconWrapper.getAttribute("class")}">
+  <svg viewBox="0 0 24 20" fill="currentColor" class="${helpIcon.getAttribute("class")}" style="width: auto;">
+    <path d="M7.446,9.924c-0,0.846 -0.105,1.593 -0.315,2.234c-0.21,0.644 -0.497,1.181 -0.86,1.615c-0.365,0.431 -0.795,0.761 -1.292,0.982c-0.494,0.22 -1.029,0.332 -1.605,0.332l-3.374,-0l0,-10.174l3.021,0c0.645,0 1.239,0.1 1.781,0.296c0.542,0.198 1.011,0.501 1.4,0.911c0.391,0.408 0.695,0.928 0.914,1.56c0.22,0.629 0.33,1.378 0.33,2.244Zm-1.765,-0c0,-0.592 -0.067,-1.1 -0.198,-1.524c-0.134,-0.422 -0.318,-0.77 -0.554,-1.042c-0.236,-0.272 -0.518,-0.473 -0.848,-0.604c-0.332,-0.128 -0.697,-0.195 -1.096,-0.195l-1.237,-0l0,6.882l1.483,0c0.351,0 0.676,-0.076 0.977,-0.224c0.298,-0.15 0.556,-0.372 0.776,-0.668c0.22,-0.295 0.389,-0.663 0.513,-1.101c0.122,-0.439 0.184,-0.947 0.184,-1.524Z"/>
+    <path d="M14.147,15.087l-0,-4.362l-3.637,-0l-0,4.362l-1.748,-0l-0,-10.174l1.748,0l-0,4.052l3.637,-0l-0,-4.052l1.75,0l0,10.174l-1.75,-0Z"/>
+    <path d="M21.297,6.559l-0,8.528l-1.748,-0l-0,-8.528l-2.699,-0l0,-1.646l7.15,0l0,1.646l-2.703,-0Z"/>
+  </svg>
+</div>
+`);
+	
+	const button = document.getElementById("dht-connector-show-dialog");
+	button.addEventListener("click", showConnectDialog);
+	return button;
+}
+
+function getHelpIcon() {
+	return document.querySelector("div[class*='bar_'] a[href$='://support.discord.com'] > div[class*='clickable'] > svg");
+}
+
+function showConnectDialog() {
+	if (window.DHT_LOADED) {
+		alert("Discord History Tracker is already loaded.");
+		return;
+	}
+	
+	const dialogElement = document.createElement("dialog");
+	dialogElement.id = "dht-connector-dialog";
+	dialogElement.innerHTML = `
+<form id="dht-connector-dialog-form">
+  <label for="dht-connector-dialog-input-code">Connection Code</label>
+  <input id="dht-connector-dialog-input-code" type="text">
+  <p id="dht-connector-dialog-input-error"></p>
+  
+  <div id="dht-connector-dialog-buttons">
+    <button type="submit" id="dht-connector-dialog-button-connect">Connect</button>
+    <button type="button" id="dht-connector-dialog-button-close">Cancel</button>
+  </div>
+</form>
+<style>
+  #dht-connector-dialog {
+    width: 300px;
+    padding: 18px;
+    font-size: 16px;
+    border: none;
+    border-radius: 8px;
+    background-color: #313338;
+  }
+  
+  #dht-connector-dialog::backdrop {
+    background-color: rgba(0, 0, 0, 0.6);
+  }
+  
+  #dht-connector-dialog label {
+    display: block;
+    margin: 0 0 9px;
+    font-weight: 500;
+    letter-spacing: .02em;
+    color: #fbfbfb;
+  }
+  
+  #dht-connector-dialog-input-error {
+    margin: 11px 1px;
+    color: #ff484c;
+    font-size: 15px;
+    font-weight: 500;
+  }
+  
+  #dht-connector-dialog input[type="text"] {
+    box-sizing: border-box;
+    width: 100%;
+    padding: 12px 10px;
+    border: 1px solid rgba(151, 151, 159, 0.2);
+    border-radius: 8px;
+    color: #efeff0;
+    background-color: #1d1d21;
+  }
+  
+  #dht-connector-dialog-buttons {
+    margin-top: 15px;
+    display: flex;
+    justify-content: end;
+    gap: 12px;
+  }
+  
+  #dht-connector-dialog button {
+    padding: 8px 16px;
+    border: none;
+    border-radius: 8px;
+    font-size: 14px;
+    font-weight: 500;
+    color: #fff;
+    background-color: #5865f2;
+    transition: background-color 200ms ease, color 200ms ease;
+  }
+  
+  #dht-connector-dialog button:hover {
+    background-color: #4752c4;
+  }
+  
+  #dht-connector-dialog button[disabled] {
+    cursor: not-allowed;
+    opacity: 0.5;
+  }
+</style>
+	`;
+	
+	document.body.insertAdjacentElement("beforeend", dialogElement);
+	
+	const formElement = document.getElementById("dht-connector-dialog-form");
+	const codeErrorElement = document.getElementById("dht-connector-dialog-input-error");
+	const codeInputElement = document.getElementById("dht-connector-dialog-input-code");
+	const connectButtonElement = document.getElementById("dht-connector-dialog-button-connect");
+	const closeButtonElement = document.getElementById("dht-connector-dialog-button-close");
+	
+	dialogElement.addEventListener("close", function() {
+		dialogElement.remove();
+	});
+	
+	closeButtonElement.addEventListener("click", function() {
+		dialogElement.close();
+	});
+	
+	codeInputElement.addEventListener("paste", function() {
+		setTimeout(async function() {
+			const code = parseConnectionCode(codeInputElement.value);
+			if (code !== null) {
+				await onSubmit(code);
+			}
+		}, 0);
+	});
+	
+	formElement.addEventListener("submit", async function(e) {
+		e.preventDefault();
+		
+		const code = parseConnectionCode(codeInputElement.value);
+		if (code === null) {
+			codeErrorElement.innerText = "Code is not valid.";
+		}
+		else {
+			await onSubmit(code);
+		}
+	});
+	
+	let isSubmitting = false;
+	
+	async function onSubmit(code) {
+		if (isSubmitting) {
+			return;
+		}
+		
+		isSubmitting = true;
+		connectButtonElement.setAttribute("disabled", "");
+		try {
+			await loadTrackingScript(code);
+		} catch (e) {
+			onError("Could not load tracking script.", e);
+		} finally {
+			isSubmitting = false;
+			connectButtonElement.removeAttribute("disabled");
+		}
+	}
+	
+	async function loadTrackingScript(code) {
+		const trackingScript = await getTrackingScript(code.port, code.token);
+		
+		if (dialogElement.isConnected) {
+			// noinspection DynamicallyGeneratedCodeJS
+			eval(trackingScript);
+			dialogElement.close();
+		}
+	}
+	
+	function onError(message, e) {
+		console.error(message, e);
+		codeErrorElement.innerText = message;
+	}
+	
+	dialogElement.showModal();
+}
+
+/**
+ * @param {string} code
+ * @return {?{port: number, token: string}}
+ */
+function parseConnectionCode(code) {
+	if (code.length > 5 + 1 + 100) {
+		return null;
+	}
+	
+	const match = code.match(/^(\d{1,5}):([a-zA-Z0-9]{1,100})$/);
+	if (!match) {
+		return null;
+	}
+	
+	const port = Number(match[1]);
+	if (port < 0 || port > 65535) {
+		return null;
+	}
+	
+	return { port, token: match[2] };
+}
+
+async function getTrackingScript(port, token) {
+	const url = "http://127.0.0.1:" + port + "/get-tracking-script?token=" + encodeURIComponent(token);
+	const response = await fetch(url, {
+		credentials: "omit",
+		signal: AbortSignal.timeout(2000),
+	});
+	
+	if (!response.ok) {
+		throw response.status + " " + response.statusText;
+	}
+	
+	if (response.headers.get("X-DHT") !== "1") {
+		throw "Invalid response";
+	}
+	
+	return await response.text();
+}

app/Resources/Tracker/scripts/discord.js

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

app/Resources/Tracker/scripts/state.js

@@ -142,11 +142,19 @@ const STATE = (function() {
 			if (DISCORD.CHANNEL_TYPE.isPrivate(channelInfo.type)) {
 				server.id = channelInfo.id;
 				server.name = channel.name = getPrivateChannelName(channelInfo);
+				
+				if (channelInfo.icon) {
+					server.icon = channelInfo.icon;
+				}
 			}
 			else if (serverInfo) {
 				server.id = serverInfo.id;
 				server.name = serverInfo.name;
 				channel.name = channelInfo.name;
+				
+				if (serverInfo.icon) {
+					server.icon = serverInfo.icon;
+				}
 			}
 			else {
 				return;

app/Resources/Tracker/scripts/types.js

@@ -2,6 +2,7 @@
  * @name DiscordGuild
  * @property {String} id
  * @property {String} name
+ * @property {String|null|undefined} [icon]
  */
 
 /**
@@ -14,6 +15,7 @@
  * @property {Number} [position]
  * @property {String} [topic]
  * @property {Boolean} [nsfw]
+ * @property {String|null|undefined} [icon]
  * @property {DiscordUser[]} [rawRecipients]
  */
 

app/Resources/Tracker/scripts/webpack.js

@@ -1,8 +1,8 @@
 /**
  * Parts copied from Better Discord, licensed under Apache License 2.0.
  *
- * https://github.com/BetterDiscord/BetterDiscord/blob/78edeb77c60542a57884686c4ba98f997c886fad/renderer/src/modules/webpackmodules.js
+ * https://github.com/BetterDiscord/BetterDiscord/blob/2752daf64f98625fc67c569361bd56021307d058/renderer/src/modules/webpackmodules.js
- * https://github.com/BetterDiscord/BetterDiscord/blob/78edeb77c60542a57884686c4ba98f997c886fad/LICENSE
+ * https://github.com/BetterDiscord/BetterDiscord/blob/2752daf64f98625fc67c569361bd56021307d058/LICENSE
  */
 class WEBPACK {
 	static get require() {
@@ -17,13 +17,15 @@ class WEBPACK {
 		 */
 		let hookedRequire;
 		
-		const id = "dht-webpackmodules-" + new Date().getTime();
+		const id = Symbol("dht-webpackmodules-" + new Date().getTime());
 		if (typeof (window["webpackChunkdiscord_app"]) !== "undefined") {
-			window["webpackChunkdiscord_app"].push([ [ id ], {}, internalRequire => hookedRequire = internalRequire ]);
+			window["webpackChunkdiscord_app"].push([ [ id ], {}, internalRequire => {
+				if ("b" in internalRequire) {
+					hookedRequire = internalRequire;
+				}
+			}]);
 		}
 		
-		delete hookedRequire.m[id];
-		delete hookedRequire.c[id];
 		return this._require = hookedRequire;
 	}
 	
@@ -86,7 +88,7 @@ class WEBPACK {
 			return modules[0];
 		}
 		
-		console.error("[DHT] Cannot find module " + name + ", results found:", modules.length);
+		console.error("[DHT] Cannot find module " + name + ", results found:", modules.length, modules);
 		return null;
 	}
 	

app/Resources/Viewer/scripts/discord.mjs

@@ -107,7 +107,7 @@ export default (function() {
 	const isImageUrl = function(url) {
 		const dot = url.pathname.lastIndexOf(".");
 		const ext = dot === -1 ? "" : url.pathname.substring(dot).toLowerCase();
-		return ext === ".png" || ext === ".gif" || ext === ".jpg" || ext === ".jpeg";
+		return ext === ".png" || ext === ".gif" || ext === ".jpg" || ext === ".jpeg" || ext === ".webp" || ext === ".avif";
 	};
 	
 	return {

app/Server/Data/FileUrl.cs

@@ -0,0 +1,9 @@
+namespace DHT.Server.Data;
+
+public readonly record struct FileUrl(string NormalizedUrl, string DownloadUrl, string? Type) {
+	public FileUrl(string url, string? type) : this(url, url, type) {}
+	
+	public Download ToPendingDownload() {
+		return new Download(NormalizedUrl, DownloadUrl, DownloadStatus.Pending, Type, size: null);
+	}
+}

app/Server/Data/Server.cs

@@ -1,7 +1,12 @@
+using DHT.Server.Download;
+
 namespace DHT.Server.Data;
 
 public readonly struct Server {
 	public ulong Id { get; init; }
 	public string Name { get; init; }
 	public ServerType? Type { get; init; }
+	public string? IconHash { get; init; }
+	
+	internal FileUrl? IconUrl => Type == null || IconHash == null ? null : DownloadLinkExtractor.ServerIcon(Type.Value, Id, IconHash);
 }

app/Server/Data/Settings/SettingsKey.cs

@@ -3,6 +3,7 @@ using System.Diagnostics.CodeAnalysis;
 namespace DHT.Server.Data.Settings;
 
 public static class SettingsKey {
+	public static Bool SeparateFileForDownloads { get; } = new ("separate_file_for_downloads");
 	public static Bool DownloadsAutoStart { get; } = new ("downloads_auto_start");
 	public static Bool DownloadsLimitSize { get; } = new ("downloads_limit_size");
 	public static UnsignedLong DownloadsMaximumSize { get; } = new ("downloads_maximum_size");

app/Server/Data/User.cs

@@ -1,9 +1,13 @@
+using DHT.Server.Download;
+
 namespace DHT.Server.Data;
 
 public readonly struct User {
 	public ulong Id { get; init; }
 	public string Name { get; init; }
 	public string? DisplayName { get; init; }
-	public string? AvatarUrl { get; init; }
+	public string? AvatarHash { get; init; }
 	public string? Discriminator { get; init; }
+	
+	internal FileUrl? AvatarUrl => AvatarHash == null ? null : DownloadLinkExtractor.UserAvatar(Id, AvatarHash);
 }

app/Server/Database/DatabaseExtensions.cs

@@ -1,34 +0,0 @@
-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 async Task AddFrom(this IDatabaseFile target, IDatabaseFile source) {
-		await target.Users.Add(await source.Users.Get().ToListAsync());
-		await target.Servers.Add(await source.Servers.Get().ToListAsync());
-		await target.Channels.Add(await source.Channels.Get().ToListAsync());
-		
-		const int MessageBatchSize = 100;
-		List<Message> batchedMessages = new (MessageBatchSize);
-		
-		await foreach (Message message in source.Messages.Get()) {
-			batchedMessages.Add(message);
-			
-			if (batchedMessages.Count >= MessageBatchSize) {
-				await target.Messages.Add(batchedMessages);
-				batchedMessages.Clear();
-			}
-		}
-		
-		await target.Messages.Add(batchedMessages);
-		
-		await foreach (Data.Download download in source.Downloads.Get()) {
-			if (download.Status != DownloadStatus.Success || !await source.Downloads.GetDownloadData(download.NormalizedUrl, stream => target.Downloads.AddDownload(download, stream))) {
-				await target.Downloads.AddDownload(download, stream: null);
-			}
-		}
-	}
-}

app/Server/Database/DummyDatabaseFile.cs

@@ -19,6 +19,10 @@ sealed class DummyDatabaseFile : IDatabaseFile {
 	
 	private DummyDatabaseFile() {}
 	
+	public Task<string?> GetVersion() {
+		return Task.FromResult<string?>(null);
+	}
+	
 	public Task Vacuum() {
 		return Task.CompletedTask;
 	}

app/Server/Database/Export/SnowflakeJsonSerializer.cs

@@ -1,16 +1,20 @@
 using System;
+using System.Buffers.Text;
+using System.Diagnostics;
 using System.Text.Json;
 using System.Text.Json.Serialization;
 
 namespace DHT.Server.Database.Export;
 
 sealed class SnowflakeJsonSerializer : JsonConverter<Snowflake> {
+	private const int MaxUlongStringLength = 20;
+	
 	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());
+		writer.WriteStringValue(Format(value, stackalloc byte[MaxUlongStringLength]));
 	}
 	
 	public override Snowflake ReadAsPropertyName(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
@@ -18,6 +22,14 @@ sealed class SnowflakeJsonSerializer : JsonConverter<Snowflake> {
 	}
 	
 	public override void WriteAsPropertyName(Utf8JsonWriter writer, Snowflake value, JsonSerializerOptions options) {
-		writer.WritePropertyName(value.Id.ToString());
+		writer.WritePropertyName(Format(value, stackalloc byte[MaxUlongStringLength]));
+	}
+	
+	private static ReadOnlySpan<byte> Format(Snowflake value, Span<byte> destination) {
+		if (!Utf8Formatter.TryFormat(value.Id, destination, out int bytesWritten)) {
+			Debug.Fail("Failed to format Snowflake value.");
+		}
+		
+		return destination[..bytesWritten];
 	}
 }

app/Server/Database/Export/ViewerJson.cs

@@ -23,6 +23,9 @@ static class ViewerJson {
 	public sealed class JsonServer {
 		public required string Name { get; init; }
 		public required string Type { get; init; }
+		
+		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
+		public string? IconUrl { get; init; }
 	}
 	
 	public sealed class JsonChannel {
@@ -30,7 +33,7 @@ static class ViewerJson {
 		public required string Name { get; init; }
 		
 		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
-		public string? Parent { get; init; }
+		public Snowflake? Parent { get; init; }
 		
 		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
 		public int? Position { get; init; }
@@ -55,7 +58,7 @@ static class ViewerJson {
 		public long? Te { get; init; }
 		
 		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
-		public string? R { get; init; }
+		public Snowflake? R { get; init; }
 		
 		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
 		public JsonMessageAttachment[]? A { get; init; }
@@ -80,7 +83,7 @@ static class ViewerJson {
 	
 	public sealed class JsonMessageReaction {
 		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
-		public string? Id { get; init; }
+		public Snowflake? Id { get; init; }
 		
 		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
 		public string? N { get; init; }

app/Server/Database/Export/ViewerJsonExport.cs

@@ -2,13 +2,15 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Runtime.CompilerServices;
 using System.Text.Json;
 using System.Threading;
+using System.Threading.Channels;
 using System.Threading.Tasks;
 using DHT.Server.Data;
 using DHT.Server.Data.Filters;
 using DHT.Utils.Logging;
+using Channel = System.Threading.Channels.Channel;
+using DiscordChannel = DHT.Server.Data.Channel;
 
 namespace DHT.Server.Database.Export;
 
@@ -18,12 +20,12 @@ static class ViewerJsonExport {
 	public static async Task GetMetadata(Stream stream, IDatabaseFile db, MessageFilter? filter = null, CancellationToken cancellationToken = default) {
 		Perf perf = Log.Start();
 		
-		var includedChannels = new List<Channel>();
+		var includedChannels = new List<DiscordChannel>();
 		var includedServerIds = new HashSet<ulong>();
 		
 		HashSet<ulong>? channelIdFilter = filter?.ChannelIds;
 		
-		await foreach (Channel channel in db.Channels.Get(cancellationToken)) {
+		await foreach (DiscordChannel channel in db.Channels.Get(cancellationToken)) {
 			if (channelIdFilter == null || channelIdFilter.Contains(channel.Id)) {
 				includedChannels.Add(channel);
 				includedServerIds.Add(channel.Server);
@@ -53,11 +55,30 @@ static class ViewerJsonExport {
 		
 		ReadOnlyMemory<byte> newLine = "\n"u8.ToArray();
 		
-		await foreach (ViewerJson.JsonMessage message in GenerateMessageList(db, filter, cancellationToken)) {
+		Channel<Message> channel = Channel.CreateBounded<Message>(new BoundedChannelOptions(32) {
-			await JsonSerializer.SerializeAsync(stream, message, ViewerJsonMessageContext.Default.JsonMessage, cancellationToken);
+			SingleWriter = true,
+			SingleReader = true,
+			AllowSynchronousContinuations = true,
+			FullMode = BoundedChannelFullMode.Wait,
+		});
+		
+		Task writerTask = Task.Run(async () => {
+			try {
+				await foreach (Message message in db.Messages.Get(filter, cancellationToken)) {
+					await channel.Writer.WriteAsync(message, cancellationToken);
+				}
+			} finally {
+				channel.Writer.Complete();
+			}
+		}, cancellationToken);
+		
+		await foreach (Message message in channel.Reader.ReadAllAsync(cancellationToken)) {
+			await JsonSerializer.SerializeAsync(stream, ToJsonMessage(message), ViewerJsonMessageContext.Default.JsonMessage, cancellationToken);
 			await stream.WriteAsync(newLine, cancellationToken);
 		}
 		
+		await writerTask;
+		
 		perf.Step("Generate and serialize messages to JSON");
 		perf.End();
 	}
@@ -69,7 +90,7 @@ static class ViewerJsonExport {
 			users[user.Id] = new ViewerJson.JsonUser {
 				Name = user.Name,
 				DisplayName = user.DisplayName,
-				Avatar = user.AvatarUrl,
+				Avatar = user.AvatarHash,
 			};
 		}
 		
@@ -87,20 +108,21 @@ static class ViewerJsonExport {
 			servers[server.Id] = new ViewerJson.JsonServer {
 				Name = server.Name,
 				Type = ServerTypes.ToJsonViewerString(server.Type),
+				IconUrl = server.IconUrl?.DownloadUrl,
 			};
 		}
 		
 		return servers;
 	}
 	
-	private static Dictionary<Snowflake, ViewerJson.JsonChannel> GenerateChannelList(List<Channel> includedChannels) {
+	private static Dictionary<Snowflake, ViewerJson.JsonChannel> GenerateChannelList(List<DiscordChannel> includedChannels) {
 		var channels = new Dictionary<Snowflake, ViewerJson.JsonChannel>();
 		
-		foreach (Channel channel in includedChannels) {
+		foreach (DiscordChannel channel in includedChannels) {
 			channels[channel.Id] = new ViewerJson.JsonChannel {
 				Server = channel.Server,
 				Name = channel.Name,
-				Parent = channel.ParentId?.ToString(),
+				Parent = channel.ParentId,
 				Position = channel.Position,
 				Topic = channel.Topic,
 				Nsfw = channel.Nsfw,
@@ -110,16 +132,15 @@ static class ViewerJsonExport {
 		return channels;
 	}
 	
-	private static async IAsyncEnumerable<ViewerJson.JsonMessage> GenerateMessageList(IDatabaseFile db, MessageFilter? filter, [EnumeratorCancellation] CancellationToken cancellationToken) {
+	private static ViewerJson.JsonMessage ToJsonMessage(Message message) {
-		await foreach (Message message in db.Messages.Get(filter, cancellationToken)) {
+		return new ViewerJson.JsonMessage {
-			yield return new ViewerJson.JsonMessage {
 			Id = message.Id,
 			C = message.Channel,
 			U = message.Sender,
 			T = message.Timestamp,
 			M = string.IsNullOrEmpty(message.Text) ? null : message.Text,
 			Te = message.EditTimestamp,
-				R = message.RepliedToId?.ToString(),
+			R = message.RepliedToId,
 			
 			A = message.Attachments.IsEmpty ? null : message.Attachments.Select(static attachment => {
 				var a = new ViewerJson.JsonMessageAttachment {
@@ -138,7 +159,7 @@ static class ViewerJsonExport {
 			E = message.Embeds.IsEmpty ? null : 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(),
+				Id = reaction.EmojiId,
 				N = reaction.EmojiName,
 				A = reaction.EmojiFlags.HasFlag(EmojiFlags.Animated),
 				C = reaction.Count,
@@ -146,4 +167,3 @@ static class ViewerJsonExport {
 		};
 	}
 }
-}

app/Server/Database/IDatabaseFile.cs

@@ -14,5 +14,6 @@ public interface IDatabaseFile : IAsyncDisposable {
 	IMessageRepository Messages { get; }
 	IDownloadRepository Downloads { get; }
 	
+	Task<string?> GetVersion();
 	Task Vacuum();
 }

app/Server/Database/Import/DatabaseMerging.cs

@@ -0,0 +1,77 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+
+namespace DHT.Server.Database.Import;
+
+public static class DatabaseMerging {
+	public static async Task Merge(this IDatabaseFile target, IDatabaseFile source, IProgressCallback callback) {
+		// Import downloads first, otherwise automatic downloads would try to re-download files from other imported data.
+		await MergeDownloads(target, source, callback);
+		
+		callback.OnImportingMetadata();
+		await target.Users.Add(await source.Users.Get().ToListAsync());
+		await target.Servers.Add(await source.Servers.Get().ToListAsync());
+		await target.Channels.Add(await source.Channels.Get().ToListAsync());
+		
+		await MergeMessages(target, source, callback);
+	}
+	
+	private static async Task MergeDownloads(IDatabaseFile target, IDatabaseFile source, IProgressCallback callback) {
+		const int ReportBatchSize = 100;
+		
+		long totalDownloads = await source.Downloads.Count();
+		long importedDownloads = 0;
+		
+		callback.OnDownloadsImported(importedDownloads, totalDownloads);
+		
+		await foreach (Data.Download download in source.Downloads.Get()) {
+			if (download.Status != DownloadStatus.Success || !await source.Downloads.GetDownloadData(download.NormalizedUrl, stream => target.Downloads.AddDownload(download, stream))) {
+				await target.Downloads.AddDownload(download, stream: null);
+			}
+			
+			if (++importedDownloads % ReportBatchSize == 0) {
+				callback.OnDownloadsImported(importedDownloads, totalDownloads);
+			}
+		}
+		
+		callback.OnDownloadsImported(totalDownloads, totalDownloads);
+	}
+	
+	private static async Task MergeMessages(IDatabaseFile target, IDatabaseFile source, IProgressCallback callback) {
+		const int MessageBatchSize = 100;
+		const int ReportEveryBatches = 10;
+		List<Message> batchedMessages = new (MessageBatchSize);
+		
+		long totalMessages = await source.Messages.Count();
+		long importedMessages = 0;
+		
+		callback.OnMessagesImported(importedMessages, totalMessages);
+		
+		await foreach (Message message in source.Messages.Get()) {
+			batchedMessages.Add(message);
+			
+			if (batchedMessages.Count >= MessageBatchSize) {
+				await target.Messages.Add(batchedMessages);
+				
+				importedMessages += batchedMessages.Count;
+				
+				if (importedMessages % (MessageBatchSize * ReportEveryBatches) == 0) {
+					callback.OnMessagesImported(importedMessages, totalMessages);
+				}
+				
+				batchedMessages.Clear();
+			}
+		}
+		
+		await target.Messages.Add(batchedMessages);
+		callback.OnMessagesImported(totalMessages, totalMessages);
+	}
+	
+	public interface IProgressCallback {
+		void OnImportingMetadata();
+		void OnMessagesImported(long finished, long total);
+		void OnDownloadsImported(long finished, long total);
+	}
+}

app/Server/Database/Import/LegacyArchiveImport.cs

@@ -106,7 +106,7 @@ public static class LegacyArchiveImport {
 			users[userindex[userId]] = new User {
 				Id = userId,
 				Name = userObj.RequireString("name", path),
-				AvatarUrl = userObj.HasKey("avatar") ? userObj.RequireString("avatar", path) : null,
+				AvatarHash = userObj.HasKey("avatar") ? userObj.RequireString("avatar", path) : null,
 				Discriminator = userObj.HasKey("tag") ? userObj.RequireString("tag", path) : null,
 			};
 		}

app/Server/Database/Repositories/IChannelRepository.cs

@@ -1,15 +1,14 @@
-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.Utils.Observables;
 
 namespace DHT.Server.Database.Repositories;
 
 public interface IChannelRepository {
-	IObservable<long> TotalCount { get; }
+	ObservableValue<long> TotalCount { get; }
 	
 	Task Add(IReadOnlyList<Channel> channels);
 	
@@ -20,7 +19,7 @@ public interface IChannelRepository {
 	Task<int> RemoveUnreachable();
 	
 	internal sealed class Dummy : IChannelRepository {
-		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+		public ObservableValue<long> TotalCount { get; } = new (0L);
 		
 		public Task Add(IReadOnlyList<Channel> channels) {
 			return Task.CompletedTask;

app/Server/Database/Repositories/IDownloadRepository.cs

@@ -2,25 +2,26 @@ 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;
 using DHT.Server.Data.Aggregations;
 using DHT.Server.Data.Filters;
 using DHT.Server.Download;
+using DHT.Utils.Observables;
 
 namespace DHT.Server.Database.Repositories;
 
 public interface IDownloadRepository {
-	IObservable<long> TotalCount { get; }
+	ObservableValue<long> TotalCount { get; }
 	
 	Task AddDownload(Data.Download item, Stream? stream);
 	
-	Task<long> Count(DownloadItemFilter filter, CancellationToken cancellationToken = default);
+	Task<long> Count(DownloadItemFilter? filter = null, CancellationToken cancellationToken = default);
 	
 	Task<DownloadStatusStatistics> GetStatistics(DownloadItemFilter nonSkippedFilter, CancellationToken cancellationToken = default);
 	
-	IAsyncEnumerable<Data.Download> Get();
+	IAsyncEnumerable<Data.Download> Get(DownloadItemFilter? filter = null);
 	
 	Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor);
 	
@@ -34,16 +35,16 @@ public interface IDownloadRepository {
 	
 	Task Remove(ICollection<string> normalizedUrls);
 	
-	IAsyncEnumerable<Data.Download> FindAllDownloadableUrls(CancellationToken cancellationToken = default);
+	IAsyncEnumerable<FileUrl> FindReachableFiles(CancellationToken cancellationToken = default);
 	
 	internal sealed class Dummy : IDownloadRepository {
-		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+		public ObservableValue<long> TotalCount { get; } = new (0L);
 		
 		public Task AddDownload(Data.Download item, Stream? stream) {
 			return Task.CompletedTask;
 		}
 		
-		public Task<long> Count(DownloadItemFilter filter, CancellationToken cancellationToken) {
+		public Task<long> Count(DownloadItemFilter? filter, CancellationToken cancellationToken) {
 			return Task.FromResult(0L);
 		}
 		
@@ -51,7 +52,7 @@ public interface IDownloadRepository {
 			return Task.FromResult(new DownloadStatusStatistics());
 		}
 		
-		public IAsyncEnumerable<Data.Download> Get() {
+		public IAsyncEnumerable<Data.Download> Get(DownloadItemFilter? filter) {
 			return AsyncEnumerable.Empty<Data.Download>();
 		}
 		
@@ -79,8 +80,8 @@ public interface IDownloadRepository {
 			return Task.CompletedTask;
 		}
 		
-		public IAsyncEnumerable<Data.Download> FindAllDownloadableUrls(CancellationToken cancellationToken) {
+		public IAsyncEnumerable<FileUrl> FindReachableFiles(CancellationToken cancellationToken) {
-			return AsyncEnumerable.Empty<Data.Download>();
+			return AsyncEnumerable.Empty<FileUrl>();
 		}
 	}
 }

app/Server/Database/Repositories/IMessageRepository.cs

@@ -1,16 +1,15 @@
-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;
+using DHT.Utils.Observables;
 
 namespace DHT.Server.Database.Repositories;
 
 public interface IMessageRepository {
-	IObservable<long> TotalCount { get; }
+	ObservableValue<long> TotalCount { get; }
 	
 	Task Add(IReadOnlyList<Message> messages);
 	
@@ -25,7 +24,7 @@ public interface IMessageRepository {
 	Task<int> RemoveUnreachableAttachments();
 	
 	internal sealed class Dummy : IMessageRepository {
-		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+		public ObservableValue<long> TotalCount { get; } = new (0L);
 		
 		public Task Add(IReadOnlyList<Message> messages) {
 			return Task.CompletedTask;

app/Server/Database/Repositories/IServerRepository.cs

@@ -1,14 +1,13 @@
-using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Reactive.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using DHT.Utils.Observables;
 
 namespace DHT.Server.Database.Repositories;
 
 public interface IServerRepository {
-	IObservable<long> TotalCount { get; }
+	ObservableValue<long> TotalCount { get; }
 	
 	Task Add(IReadOnlyList<Data.Server> servers);
 	
@@ -19,7 +18,7 @@ public interface IServerRepository {
 	Task<int> RemoveUnreachable();
 	
 	internal sealed class Dummy : IServerRepository {
-		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+		public ObservableValue<long> TotalCount { get; } = new (0L);
 		
 		public Task Add(IReadOnlyList<Data.Server> servers) {
 			return Task.CompletedTask;

app/Server/Database/Repositories/IUserRepository.cs

@@ -1,15 +1,14 @@
-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.Utils.Observables;
 
 namespace DHT.Server.Database.Repositories;
 
 public interface IUserRepository {
-	IObservable<long> TotalCount { get; }
+	ObservableValue<long> TotalCount { get; }
 	
 	Task Add(IReadOnlyList<User> users);
 	
@@ -20,7 +19,7 @@ public interface IUserRepository {
 	Task<int> RemoveUnreachable();
 	
 	internal sealed class Dummy : IUserRepository {
-		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
+		public ObservableValue<long> TotalCount { get; } = new (0L);
 		
 		public Task Add(IReadOnlyList<User> users) {
 			return Task.CompletedTask;

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

@@ -1,23 +1,27 @@
 using System;
-using System.Reactive.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Utils.Logging;
+using DHT.Utils.Observables;
 using DHT.Utils.Tasks;
 
 namespace DHT.Server.Database.Sqlite.Repositories;
 
 abstract class BaseSqliteRepository : IDisposable {
-	private readonly ObservableThrottledTask<long> totalCountTask;
+	private readonly ThrottledTask<long> totalCountTask;
 	
-	public IObservable<long> TotalCount { get; }
+	public ObservableValue<long> TotalCount { get; } = new (0L);
 	
 	protected BaseSqliteRepository(Log log) {
-		totalCountTask = new ObservableThrottledTask<long>(log, TaskScheduler.Default);
+		totalCountTask = new ThrottledTask<long>(log, SetTotalCount, TimeSpan.Zero, TaskScheduler.Default);
-		TotalCount = totalCountTask.DistinctUntilChanged();
 		UpdateTotalCount();
 	}
 	
+	private Task SetTotalCount(long newCount) {
+		TotalCount.Set(newCount);
+		return Task.CompletedTask;
+	}
+	
 	public void Dispose() {
 		totalCountTask.Dispose();
 	}

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

@@ -18,6 +18,8 @@ namespace DHT.Server.Database.Sqlite.Repositories;
 sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRepository(Log), IDownloadRepository {
 	private static readonly Log Log = Log.ForType<SqliteDownloadRepository>();
 	
+	public const string Schema = "downloads";
+	
 	internal sealed class NewDownloadCollector : IAsyncDisposable {
 		private readonly SqliteDownloadRepository repository;
 		private bool hasChanged = false;
@@ -60,6 +62,15 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 			hasChanged |= await metadataCmd.ExecuteNonQueryAsync() > 0;
 		}
 		
+		public Task AddIfNotNull(Data.Download? download) {
+			if (download != null) {
+				return Add(download);
+			}
+			else {
+				return Task.CompletedTask;
+			}
+		}
+		
 		public void OnCommitted() {
 			if (hasChanged) {
 				repository.UpdateTotalCount();
@@ -71,7 +82,25 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 		}
 	}
 	
+	private static SqliteBlob BlobReference(ISqliteConnection conn, long rowid, bool readOnly) {
+		string schema = conn.HasAttachedDatabase(Schema) ? Schema : "main";
+		return new SqliteBlob(conn.InnerConnection, databaseName: schema, tableName: "download_blobs", columnName: "blob", rowid, readOnly);
+	}
+	
 	public async Task AddDownload(Data.Download item, Stream? stream) {
+		ulong? actualSize;
+		
+		if (stream is not null) {
+			actualSize = (ulong) stream.Length;
+			
+			if (actualSize != item.Size) {
+				Log.Warn("Download size differs from its metadata - metadata size: " + item.Size + " B, actual size: " + actualSize + " B, url: " + item.NormalizedUrl);
+			}
+		}
+		else {
+			actualSize = item.Size;
+		}
+		
 		await using (var conn = await pool.Take()) {
 			await conn.BeginTransactionAsync();
 			
@@ -87,7 +116,7 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 			metadataCmd.Set(":download_url", item.DownloadUrl);
 			metadataCmd.Set(":status", (int) item.Status);
 			metadataCmd.Set(":type", item.Type);
-			metadataCmd.Set(":size", item.Size);
+			metadataCmd.Set(":size", actualSize);
 			await metadataCmd.ExecuteNonQueryAsync();
 			
 			if (stream == null) {
@@ -107,10 +136,10 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 				);
 				
 				upsertBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, item.NormalizedUrl);
-				upsertBlobCmd.AddAndSet(":blob_length", SqliteType.Integer, item.Size);
+				upsertBlobCmd.AddAndSet(":blob_length", SqliteType.Integer, actualSize);
 				long rowid = await upsertBlobCmd.ExecuteLongScalarAsync();
 				
-				await using var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid);
+				await using var blob = BlobReference(conn, rowid, readOnly: false);
 				await stream.CopyToAsync(blob);
 			}
 			
@@ -181,10 +210,10 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 		};
 	}
 	
-	public async IAsyncEnumerable<Data.Download> Get() {
+	public async IAsyncEnumerable<Data.Download> Get(DownloadItemFilter? filter) {
 		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 cmd = conn.Command("SELECT normalized_url, download_url, status, type, size FROM download_metadata" + filter.GenerateConditions().BuildWhereClause());
 		await using var reader = await cmd.ExecuteReaderAsync();
 		
 		while (await reader.ReadAsync()) {
@@ -214,7 +243,7 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 			rowid = reader.GetInt64(0);
 		}
 		
-		await using (var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid, readOnly: true)) {
+		await using (var blob = BlobReference(conn, rowid, readOnly: true)) {
 			await dataProcessor(blob);
 		}
 		
@@ -249,7 +278,7 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 			rowid = reader.GetInt64(2);
 		}
 		
-		await using (var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid, readOnly: true)) {
+		await using (var blob = BlobReference(conn, rowid, readOnly: true)) {
 			await dataProcessor(new Data.Download(normalizedUrl, downloadUrl, DownloadStatus.Success, type, (ulong) blob.Length), blob, cancellationToken);
 		}
 		
@@ -277,12 +306,14 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 			await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
 			
 			while (await reader.ReadAsync(cancellationToken)) {
-				found.Add(new DownloadItem {
+				var item = new DownloadItem(
-					NormalizedUrl = reader.GetString(0),
+					NormalizedUrl: reader.GetString(0),
-					DownloadUrl = reader.GetString(1),
+					DownloadUrl: reader.GetString(1),
-					Type = reader.IsDBNull(2) ? null : reader.GetString(2),
+					Type: reader.IsDBNull(2) ? null : reader.GetString(2),
-					Size = reader.IsDBNull(3) ? null : reader.GetUint64(3),
+					Size: reader.IsDBNull(3) ? null : reader.GetUint64(3)
-				});
+				);
+				
+				found.Add(item);
 			}
 		}
 		
@@ -341,14 +372,17 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 		UpdateTotalCount();
 	}
 	
-	public async IAsyncEnumerable<Data.Download> FindAllDownloadableUrls([EnumeratorCancellation] CancellationToken cancellationToken = default) {
+	public async IAsyncEnumerable<FileUrl> FindReachableFiles([EnumeratorCancellation] CancellationToken cancellationToken) {
 		await using var conn = await pool.Take();
 		
-		await using (var cmd = conn.Command("SELECT normalized_url, download_url, type, size FROM attachments")) {
+		await using (var cmd = conn.Command("SELECT type, normalized_url, download_url FROM attachments")) {
 			await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
 			
 			while (await reader.ReadAsync(cancellationToken)) {
-				yield return DownloadLinkExtractor.FromAttachment(reader.GetString(0), reader.GetString(1), reader.IsDBNull(2) ? null : reader.GetString(2), reader.GetUint64(3));
+				string? type = reader.IsDBNull(0) ? null : reader.GetString(0);
+				string normalizedUrl = reader.GetString(1);
+				string downloadUrl = reader.GetString(2);
+				yield return new FileUrl(normalizedUrl, downloadUrl, type);
 			}
 		}
 		
@@ -356,8 +390,31 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 			await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
 			
 			while (await reader.ReadAsync(cancellationToken)) {
-				var result = await DownloadLinkExtractor.TryFromEmbedJson(reader.GetStream(0));
+				if (await DownloadLinkExtractor.TryFromEmbedJson(reader.GetStream(0)) is {} result) {
-				if (result is not null) {
+					yield return result;
+				}
+			}
+		}
+		
+		await using (var cmd = conn.Command("SELECT DISTINCT emoji_id, emoji_flags FROM message_reactions WHERE emoji_id IS NOT NULL")) {
+			await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
+			
+			while (await reader.ReadAsync(cancellationToken)) {
+				ulong emojiId = reader.GetUint64(0);
+				EmojiFlags emojiFlags = (EmojiFlags) reader.GetInt16(1);
+				yield return DownloadLinkExtractor.Emoji(emojiId, emojiFlags);
+			}
+		}
+		
+		await using (var cmd = conn.Command("SELECT id, type, icon_hash FROM servers WHERE icon_hash IS NOT NULL")) {
+			await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
+			
+			while (await reader.ReadAsync(cancellationToken)) {
+				ulong id = reader.GetUint64(0);
+				ServerType? type = ServerTypes.FromString(reader.GetString(1));
+				string iconHash = reader.GetString(2);
+				
+				if (DownloadLinkExtractor.ServerIcon(type, id, iconHash) is {} result) {
 					yield return result;
 				}
 			}
@@ -367,15 +424,9 @@ sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRep
 			await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
 			
 			while (await reader.ReadAsync(cancellationToken)) {
-				yield return DownloadLinkExtractor.FromUserAvatar(reader.GetUint64(0), reader.GetString(1));
+				ulong id = reader.GetUint64(0);
-			}
+				string avatarHash = reader.GetString(1);
-		}
+				yield return DownloadLinkExtractor.UserAvatar(id, avatarHash);
-		
-		await using (var cmd = conn.Command("SELECT DISTINCT emoji_id, emoji_flags FROM message_reactions WHERE emoji_id IS NOT NULL")) {
-			await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
-			
-			while (await reader.ReadAsync(cancellationToken)) {
-				yield return DownloadLinkExtractor.FromEmoji(reader.GetUint64(0), (EmojiFlags) reader.GetInt16(1));
 			}
 		}
 	}

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

@@ -10,6 +10,7 @@ using DHT.Server.Database.Repositories;
 using DHT.Server.Database.Sqlite.Utils;
 using DHT.Server.Download;
 using DHT.Utils.Logging;
+using JetBrains.Annotations;
 using Microsoft.Data.Sqlite;
 
 namespace DHT.Server.Database.Sqlite.Repositories;
@@ -17,15 +18,16 @@ namespace DHT.Server.Database.Sqlite.Repositories;
 sealed class SqliteMessageRepository(SqliteConnectionPool pool, SqliteDownloadRepository downloads) : BaseSqliteRepository(Log), IMessageRepository {
 	private static readonly Log Log = Log.ForType<SqliteMessageRepository>();
 	
+	// Moved outside the Add method due to language injections not working in local methods.
+	private static SqliteCommand DeleteByMessageId(ISqliteConnection conn, [LanguageInjection("sql", Prefix = "SELECT * FROM ")] string tableName) {
+		return conn.Delete(tableName, ("message_id", SqliteType.Integer));
+	}
+	
 	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();
@@ -137,7 +139,7 @@ sealed class SqliteMessageRepository(SqliteConnectionPool pool, SqliteDownloadRe
 						messageAttachmentCmd.Set(":attachment_id", attachmentId);
 						await messageAttachmentCmd.ExecuteNonQueryAsync();
 						
-						await downloadCollector.Add(DownloadLinkExtractor.FromAttachment(attachment));
+						await downloadCollector.Add(new Data.Download(attachment.NormalizedUrl, attachment.DownloadUrl, DownloadStatus.Pending, attachment.Type, attachment.Size));
 					}
 				}
 				
@@ -148,7 +150,7 @@ sealed class SqliteMessageRepository(SqliteConnectionPool pool, SqliteDownloadRe
 						await messageEmbedCmd.ExecuteNonQueryAsync();
 						
 						if (DownloadLinkExtractor.TryFromEmbedJson(embed.Json) is {} download) {
-							await downloadCollector.Add(download);
+							await downloadCollector.Add(download.ToPendingDownload());
 						}
 					}
 				}
@@ -163,7 +165,7 @@ sealed class SqliteMessageRepository(SqliteConnectionPool pool, SqliteDownloadRe
 						await messageReactionCmd.ExecuteNonQueryAsync();
 						
 						if (reaction.EmojiId is {} emojiId) {
-							await downloadCollector.Add(DownloadLinkExtractor.FromEmoji(emojiId, reaction.EmojiFlags));
+							await downloadCollector.Add(DownloadLinkExtractor.Emoji(emojiId, reaction.EmojiFlags).ToPendingDownload());
 						}
 					}
 				}

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

@@ -10,15 +10,9 @@ using Microsoft.Data.Sqlite;
 
 namespace DHT.Server.Database.Sqlite.Repositories;
 
-sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
+sealed class SqliteServerRepository(SqliteConnectionPool pool, SqliteDownloadRepository downloads) : BaseSqliteRepository(Log), 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();
@@ -27,13 +21,18 @@ sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
 				("id", SqliteType.Integer),
 				("name", SqliteType.Text),
 				("type", SqliteType.Text),
+				("icon_hash", SqliteType.Text),
 			]);
 			
+			await using var downloadCollector = new SqliteDownloadRepository.NewDownloadCollector(downloads, conn);
+			
 			foreach (Data.Server server in servers) {
 				cmd.Set(":id", server.Id);
 				cmd.Set(":name", server.Name);
 				cmd.Set(":type", ServerTypes.ToString(server.Type));
+				cmd.Set(":icon_hash", server.IconHash);
 				await cmd.ExecuteNonQueryAsync();
+				await downloadCollector.AddIfNotNull(server.IconUrl?.ToPendingDownload());
 			}
 			
 			await conn.CommitTransactionAsync();
@@ -50,7 +49,7 @@ sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
 	public async IAsyncEnumerable<Data.Server> Get([EnumeratorCancellation] CancellationToken cancellationToken) {
 		await using var conn = await pool.Take();
 		
-		await using var cmd = conn.Command("SELECT id, name, type FROM servers");
+		await using var cmd = conn.Command("SELECT id, name, type, icon_hash FROM servers");
 		await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
 		
 		while (await reader.ReadAsync(cancellationToken)) {
@@ -58,6 +57,7 @@ sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
 				Id = reader.GetUint64(0),
 				Name = reader.GetString(1),
 				Type = ServerTypes.FromString(reader.GetString(2)),
+				IconHash = reader.IsDBNull(3) ? null : reader.GetString(3),
 			};
 		}
 	}

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

@@ -43,10 +43,14 @@ sealed class SqliteSettingsRepository(SqliteConnectionPool pool) : ISettingsRepo
 	}
 	
 	public async Task<T?> Get<T>(SettingsKey<T> key, T? defaultValue) {
+		await using var conn = await pool.Take();
+		return await Get(conn, key, defaultValue);
+	}
+	
+	public static async Task<T?> Get<T>(ISqliteConnection conn, SettingsKey<T> key, T? defaultValue) {
 		string? value;
 		
-		await using (var conn = await pool.Take()) {
+		await using (var cmd = conn.Command("SELECT value FROM metadata WHERE key = :key")) {
-			await using var cmd = conn.Command("SELECT value FROM metadata WHERE key = :key");
 			cmd.AddAndSet(":key", SqliteType.Text, key.Key);
 			
 			await using var reader = await cmd.ExecuteReaderAsync();

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

@@ -5,23 +5,14 @@ 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 {
+sealed class SqliteUserRepository(SqliteConnectionPool pool, SqliteDownloadRepository downloads) : BaseSqliteRepository(Log), 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();
@@ -40,13 +31,10 @@ sealed class SqliteUserRepository : BaseSqliteRepository, IUserRepository {
 				cmd.Set(":id", user.Id);
 				cmd.Set(":name", user.Name);
 				cmd.Set(":display_name", user.DisplayName);
-				cmd.Set(":avatar_url", user.AvatarUrl);
+				cmd.Set(":avatar_url", user.AvatarHash);
 				cmd.Set(":discriminator", user.Discriminator);
 				await cmd.ExecuteNonQueryAsync();
-				
+				await downloadCollector.AddIfNotNull(user.AvatarUrl?.ToPendingDownload());
-				if (user.AvatarUrl is {} avatarUrl) {
-					await downloadCollector.Add(DownloadLinkExtractor.FromUserAvatar(user.Id, avatarUrl));
-				}
 			}
 			
 			await conn.CommitTransactionAsync();
@@ -72,7 +60,7 @@ sealed class SqliteUserRepository : BaseSqliteRepository, IUserRepository {
 				Id = reader.GetUint64(0),
 				Name = reader.GetString(1),
 				DisplayName = reader.IsDBNull(2) ? null : reader.GetString(2),
-				AvatarUrl = reader.IsDBNull(3) ? null : reader.GetString(3),
+				AvatarHash = reader.IsDBNull(3) ? null : reader.GetString(3),
 				Discriminator = reader.IsDBNull(4) ? null : reader.GetString(4),
 			};
 		}

app/Server/Database/Sqlite/Schema/ISchemaUpgradeCallbacks.cs

@@ -1,9 +1,11 @@
 using System;
 using System.Threading.Tasks;
+using DHT.Server.Database.Sqlite.Utils;
 
 namespace DHT.Server.Database.Sqlite.Schema;
 
 public interface ISchemaUpgradeCallbacks {
+	Task<InitialDatabaseSettings?> GetInitialDatabaseSettings();
 	Task<bool> CanUpgrade();
 	Task Start(int versionSteps, Func<IProgressReporter, Task> doUpgrade);
 	

app/Server/Database/Sqlite/Schema/SqliteSchemaUpgradeTo11.cs

@@ -0,0 +1,11 @@
+using System.Threading.Tasks;
+using DHT.Server.Database.Sqlite.Utils;
+
+namespace DHT.Server.Database.Sqlite.Schema;
+
+sealed class SqliteSchemaUpgradeTo11 : ISchemaUpgrade {
+	async Task ISchemaUpgrade.Run(ISqliteConnection conn, ISchemaUpgradeCallbacks.IProgressReporter reporter) {
+		await reporter.MainWork("Applying schema changes...", finishedItems: 0, totalItems: 1);
+		await conn.ExecuteAsync("ALTER TABLE servers ADD icon_hash TEXT");
+	}
+}

app/Server/Database/Sqlite/Schema/SqliteSchemaUpgradeTo7.cs

@@ -124,7 +124,7 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 			await using var reader = await embedCmd.ExecuteReaderAsync();
 			
 			while (await reader.ReadAsync()) {
-				await InsertDownload(insertCmd, await DownloadLinkExtractor.TryFromEmbedJson(reader.GetStream(0)));
+				await InsertDownload(insertCmd, (await DownloadLinkExtractor.TryFromEmbedJson(reader.GetStream(0)))?.ToPendingDownload());
 			}
 		}
 		
@@ -134,7 +134,7 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 			await using var reader = await avatarCmd.ExecuteReaderAsync();
 			
 			while (await reader.ReadAsync()) {
-				await InsertDownload(insertCmd, DownloadLinkExtractor.FromUserAvatar(reader.GetUint64(0), reader.GetString(1)));
+				await InsertDownload(insertCmd, DownloadLinkExtractor.UserAvatar(reader.GetUint64(0), reader.GetString(1)).ToPendingDownload());
 			}
 		}
 		
@@ -144,7 +144,7 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 			await using var reader = await avatarCmd.ExecuteReaderAsync();
 			
 			while (await reader.ReadAsync()) {
-				await InsertDownload(insertCmd, DownloadLinkExtractor.FromEmoji(reader.GetUint64(0), (EmojiFlags) reader.GetInt16(1)));
+				await InsertDownload(insertCmd, DownloadLinkExtractor.Emoji(reader.GetUint64(0), (EmojiFlags) reader.GetInt16(1)).ToPendingDownload());
 			}
 		}
 		

app/Server/Database/Sqlite/SqliteDatabaseFile.cs

@@ -1,42 +1,46 @@
-using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
+using DHT.Server.Data.Settings;
 using DHT.Server.Database.Repositories;
 using DHT.Server.Database.Sqlite.Repositories;
 using DHT.Server.Database.Sqlite.Schema;
 using DHT.Server.Database.Sqlite.Utils;
-using Microsoft.Data.Sqlite;
+using DHT.Utils.Logging;
 
 namespace DHT.Server.Database.Sqlite;
 
 public sealed class SqliteDatabaseFile : IDatabaseFile {
+	private static readonly Log Log = Log.ForType<SqliteDatabaseFile>();
+	
 	private const int DefaultPoolSize = 5;
 	
 	public static async Task<SqliteDatabaseFile?> OpenOrCreate(string path, ISchemaUpgradeCallbacks schemaUpgradeCallbacks) {
-		var connectionString = new SqliteConnectionStringBuilder {
+		var connectionString = new SqliteConnectionStringFactory(path);
-			DataSource = path,
+		var attachedDatabaseCollector = new AttachedDatabaseCollector(path);
-			Mode = SqliteOpenMode.ReadWriteCreate,
-		};
 		
-		var pool = await SqliteConnectionPool.Create(connectionString, DefaultPoolSize);
 		bool wasOpened;
-		
+		await using (var conn = await CustomSqliteConnection.OpenUnpooled(connectionString)) {
-		try {
+			wasOpened = await new SqliteSchema(conn).Setup(attachedDatabaseCollector, schemaUpgradeCallbacks);
-			await using var conn = await pool.Take();
-			wasOpened = await new SqliteSchema(conn).Setup(schemaUpgradeCallbacks);
-		} catch (Exception) {
-			await pool.DisposeAsync();
-			throw;
 		}
 		
 		if (wasOpened) {
+			var pool = await SqliteConnectionPool.Create(connectionString, DefaultPoolSize, attachedDatabaseCollector);
 			return new SqliteDatabaseFile(path, pool);
 		}
 		else {
-			await pool.DisposeAsync();
 			return null;
 		}
 	}
 	
+	private sealed class AttachedDatabaseCollector(string path) : ISqliteAttachedDatabaseCollector {
+		public async IAsyncEnumerable<AttachedDatabase> GetAttachedDatabases(ISqliteConnection conn) {
+			bool useSeparateFileForDownloads = await SqliteSettingsRepository.Get(conn, SettingsKey.SeparateFileForDownloads, defaultValue: false);
+			if (useSeparateFileForDownloads) {
+				yield return new AttachedDatabase(path + "_downloads", SqliteDownloadRepository.Schema);
+			}
+		}
+	}
+	
 	public string Path { get; }
 	
 	public ISettingsRepository Settings => settings;
@@ -62,22 +66,42 @@ public sealed class SqliteDatabaseFile : IDatabaseFile {
 		downloads = new SqliteDownloadRepository(pool);
 		settings = new SqliteSettingsRepository(pool);
 		users = new SqliteUserRepository(pool, downloads);
-		servers = new SqliteServerRepository(pool);
+		servers = new SqliteServerRepository(pool, downloads);
 		channels = new SqliteChannelRepository(pool);
 		messages = new SqliteMessageRepository(pool, downloads);
 	}
 	
 	public async ValueTask DisposeAsync() {
-		users.Dispose();
-		servers.Dispose();
-		channels.Dispose();
 		messages.Dispose();
+		channels.Dispose();
+		servers.Dispose();
+		users.Dispose();
 		downloads.Dispose();
 		await pool.DisposeAsync();
 	}
 	
+	public async Task<string?> GetVersion() {
+		await using var conn = await pool.Take();
+		return await conn.ExecuteReaderAsync("SELECT sqlite_version()", static reader => reader?.GetString(0));
+	}
+	
 	public async Task Vacuum() {
 		await using var conn = await pool.Take();
+		
+		Perf perf = Log.Start();
 		await conn.ExecuteAsync("VACUUM");
+		perf.Step("Vacuum main schema");
+		
+		await VacuumAttachedDatabase(conn, perf, SqliteDownloadRepository.Schema);
+		
+		perf.End();
+		return;
+		
+		static async Task VacuumAttachedDatabase(ISqliteConnection conn, Perf perf, string schema) {
+			if (conn.HasAttachedDatabase(schema)) {
+				await conn.ExecuteAsync("VACUUM " + schema);
+				perf.Step("Vacuum " + schema + " schema");
+			}
+		}
 	}
 }

app/Server/Database/Sqlite/SqliteSchema.cs

@@ -1,28 +1,32 @@
 using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using System.Threading.Tasks;
+using DHT.Server.Data.Settings;
 using DHT.Server.Database.Exceptions;
+using DHT.Server.Database.Sqlite.Repositories;
 using DHT.Server.Database.Sqlite.Schema;
 using DHT.Server.Database.Sqlite.Utils;
 using DHT.Utils.Logging;
+using Microsoft.Data.Sqlite;
 
 namespace DHT.Server.Database.Sqlite;
 
-sealed class SqliteSchema {
+sealed class SqliteSchema(CustomSqliteConnection conn) {
-	internal const int Version = 10;
+	internal const int Version = 11;
 	
 	private static readonly Log Log = Log.ForType<SqliteSchema>();
 	
-	private readonly ISqliteConnection conn;
+	public async Task<bool> Setup(ISqliteAttachedDatabaseCollector attachedDatabaseCollector, ISchemaUpgradeCallbacks callbacks) {
-	
-	public SqliteSchema(ISqliteConnection conn) {
-		this.conn = conn;
-	}
-	
-	public async Task<bool> Setup(ISchemaUpgradeCallbacks callbacks) {
 		await conn.ExecuteAsync("CREATE TABLE IF NOT EXISTS metadata (key TEXT PRIMARY KEY, value TEXT)");
 		
 		string? dbVersionStr = await conn.ExecuteReaderAsync("SELECT value FROM metadata WHERE key = 'version'", static reader => reader?.GetString(0));
 		if (dbVersionStr == null) {
+			if (await callbacks.GetInitialDatabaseSettings() is {} initialSettings) {
+				await ApplyInitialSettings(initialSettings);
+				await AttachAdditionalDatabasesIfNecessary(attachedDatabaseCollector);
+			}
+			
 			await InitializeSchemas();
 		}
 		else if (!int.TryParse(dbVersionStr, out int dbVersion) || dbVersion < 1) {
@@ -37,12 +41,44 @@ sealed class SqliteSchema {
 				return false;
 			}
 			
+			await AttachAdditionalDatabasesIfNecessary(attachedDatabaseCollector);
 			await callbacks.Start(Version - dbVersion, async reporter => await UpgradeSchemas(dbVersion, reporter));
 		}
 		
 		return true;
 	}
 	
+	private async Task ApplyInitialSettings(InitialDatabaseSettings initialSettings) {
+		await using var cmd = conn.Command("INSERT INTO metadata (key, value) VALUES (:key, :value)");
+		cmd.Add("key", SqliteType.Text);
+		cmd.Add("value", SqliteType.Text);
+		
+		static async Task ApplySetting<T>(SqliteCommand cmd, SettingsKey<T> key, T value) {
+			cmd.Set("key", key.Key);
+			cmd.Set("value", key.ToString(value));
+			await cmd.ExecuteNonQueryAsync();
+		}
+		
+		if (initialSettings.SeparateFileForDownloads) {
+			await ApplySetting(cmd, SettingsKey.SeparateFileForDownloads, value: true);
+		}
+		
+		if (initialSettings.DownloadsAutoStart) {
+			await ApplySetting(cmd, SettingsKey.DownloadsAutoStart, value: true);
+		}
+	}
+	
+	[SuppressMessage("ReSharper", "WithExpressionModifiesAllMembers")]
+	private async Task AttachAdditionalDatabasesIfNecessary(ISqliteAttachedDatabaseCollector attachedDatabaseCollector) {
+		await foreach (var attachedDatabase in attachedDatabaseCollector.GetAttachedDatabases(conn)) {
+			if (!File.Exists(attachedDatabase.Path)) {
+				await using CustomSqliteConnection _ = await CustomSqliteConnection.OpenUnpooled(conn.ConnectionStringFactory with { Path = attachedDatabase.Path });
+			}
+			
+			await conn.AttachDatabase(attachedDatabase);
+		}
+	}
+	
 	private async Task InitializeSchemas() {
 		await conn.ExecuteAsync("""
 		                        CREATE TABLE users (
@@ -58,7 +94,8 @@ sealed class SqliteSchema {
 		                        CREATE TABLE servers (
 		                        	id        INTEGER PRIMARY KEY NOT NULL,
 		                        	name      TEXT NOT NULL,
-		                        	type TEXT NOT NULL
+		                        	type      TEXT NOT NULL,
+		                        	icon_hash TEXT
 		                        )
 		                        """);
 		
@@ -142,8 +179,10 @@ sealed class SqliteSchema {
 	}
 	
 	internal static async Task CreateDownloadTables(ISqliteConnection conn) {
-		await conn.ExecuteAsync("""
+		string schema = conn.HasAttachedDatabase(SqliteDownloadRepository.Schema) ? SqliteDownloadRepository.Schema : "main";
-		                        CREATE TABLE download_metadata (
+		
+		await conn.ExecuteAsync($"""
+		                         CREATE TABLE {schema}.download_metadata (
 		                         	normalized_url TEXT NOT NULL PRIMARY KEY,
 		                         	download_url   TEXT NOT NULL,
 		                         	status         INTEGER NOT NULL,
@@ -152,8 +191,8 @@ sealed class SqliteSchema {
 		                         )
 		                         """);
 		
-		await conn.ExecuteAsync("""
+		await conn.ExecuteAsync($"""
-		                        CREATE TABLE download_blobs (
+		                         CREATE TABLE {schema}.download_blobs (
 		                         	normalized_url TEXT NOT NULL PRIMARY KEY,
 		                         	blob           BLOB NOT NULL,
 		                         	FOREIGN KEY (normalized_url) REFERENCES download_metadata (normalized_url) ON UPDATE CASCADE ON DELETE CASCADE
@@ -184,6 +223,7 @@ sealed class SqliteSchema {
 			{ 7, new SqliteSchemaUpgradeTo8() },
 			{ 8, new SqliteSchemaUpgradeTo9() },
 			{ 9, new SqliteSchemaUpgradeTo10() },
+			{ 10, new SqliteSchemaUpgradeTo11() },
 		};
 		
 		Perf perf = Log.Start("from version " + dbVersion);

app/Server/Database/Sqlite/Utils/AttachedDatabase.cs

@@ -0,0 +1,3 @@
+namespace DHT.Server.Database.Sqlite.Utils;
+
+sealed record AttachedDatabase(string Path, string Schema);

app/Server/Database/Sqlite/Utils/CustomSqliteConnection.cs

@@ -0,0 +1,91 @@
+using System;
+using System.Collections.Immutable;
+using System.Data.Common;
+using System.Diagnostics.CodeAnalysis;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Data.Sqlite;
+
+namespace DHT.Server.Database.Sqlite.Utils;
+
+class CustomSqliteConnection : ISqliteConnection {
+	internal static async Task<CustomSqliteConnection> OpenUnpooled(SqliteConnectionStringFactory connectionStringFactory) {
+		SqliteConnection conn = new SqliteConnection(connectionStringFactory.Create());
+		await conn.OpenAsync();
+		
+		CustomSqliteConnection custom = new CustomSqliteConnection(connectionStringFactory, conn);
+		await custom.Setup(CancellationToken.None);
+		
+		return custom;
+	}
+	
+	internal SqliteConnectionStringFactory ConnectionStringFactory { get; }
+	public SqliteConnection InnerConnection { get; }
+	
+	private ImmutableHashSet<string> attachedDatabases = [];
+	private DbTransaction? activeTransaction;
+	
+	protected CustomSqliteConnection(SqliteConnectionStringFactory connectionStringFactory, SqliteConnection innerConnection) {
+		this.ConnectionStringFactory = connectionStringFactory;
+		this.InnerConnection = innerConnection;
+	}
+	
+	internal async Task Setup(CancellationToken cancellationToken) {
+		await this.ExecuteAsync("PRAGMA journal_mode=WAL", cancellationToken);
+		await this.ExecuteAsync("PRAGMA foreign_keys=ON", cancellationToken);
+	}
+	
+	[SuppressMessage("ReSharper", "WithExpressionModifiesAllMembers")]
+	internal async Task AttachDatabase(AttachedDatabase attachedDatabase) {
+		await this.ExecuteAsync("ATTACH DATABASE '" + attachedDatabase.Path.Replace("'", "''") + "' AS " + attachedDatabase.Schema);
+		ImmutableInterlocked.Update(ref attachedDatabases, static (set, schema) => set.Add(schema), attachedDatabase.Schema);
+	}
+	
+	public bool HasAttachedDatabase(string schema) {
+		return attachedDatabases.Contains(schema);
+	}
+	
+	public async Task BeginTransactionAsync() {
+		if (activeTransaction != null) {
+			throw new InvalidOperationException("A transaction is already active.");
+		}
+		
+		activeTransaction = await InnerConnection.BeginTransactionAsync();
+	}
+	
+	public async Task CommitTransactionAsync() {
+		if (activeTransaction == null) {
+			throw new InvalidOperationException("No active transaction to commit.");
+		}
+		
+		await activeTransaction.CommitAsync();
+		await activeTransaction.DisposeAsync();
+		activeTransaction = null;
+	}
+	
+	public async Task RollbackTransactionAsync() {
+		if (activeTransaction == null) {
+			throw new InvalidOperationException("No active transaction to rollback.");
+		}
+		
+		await activeTransaction.RollbackAsync();
+		await activeTransaction.DisposeAsync();
+		activeTransaction = null;
+	}
+	
+	public void AssignActiveTransaction(SqliteCommand command) {
+		command.Transaction = (SqliteTransaction?) activeTransaction;
+	}
+	
+	public async ValueTask DisposeAsync() {
+		if (activeTransaction != null) {
+			await RollbackTransactionAsync();
+		}
+		
+		await DisposeConnection();
+	}
+	
+	private protected virtual async ValueTask DisposeConnection() {
+		await InnerConnection.DisposeAsync();
+	}
+}

app/Server/Database/Sqlite/Utils/ISqliteAttachedDatabaseCollector.cs

@@ -0,0 +1,7 @@
+using System.Collections.Generic;
+
+namespace DHT.Server.Database.Sqlite.Utils;
+
+interface ISqliteAttachedDatabaseCollector {
+	IAsyncEnumerable<AttachedDatabase> GetAttachedDatabases(ISqliteConnection conn);
+}

app/Server/Database/Sqlite/Utils/ISqliteConnection.cs

@@ -7,6 +7,8 @@ namespace DHT.Server.Database.Sqlite.Utils;
 interface ISqliteConnection : IAsyncDisposable {
 	SqliteConnection InnerConnection { get; }
 	
+	bool HasAttachedDatabase(string schema);
+	
 	Task BeginTransactionAsync();
 	Task CommitTransactionAsync();
 	Task RollbackTransactionAsync();

app/Server/Database/Sqlite/Utils/InitialDatabaseSettings.cs

@@ -0,0 +1,3 @@
+namespace DHT.Server.Database.Sqlite.Utils;
+
+public sealed record InitialDatabaseSettings(bool SeparateFileForDownloads, bool DownloadsAutoStart);

app/Server/Database/Sqlite/Utils/SqliteConnectionPool.cs

@@ -1,6 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.Data.Common;
+using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Utils.Collections;
@@ -9,16 +9,13 @@ using Microsoft.Data.Sqlite;
 namespace DHT.Server.Database.Sqlite.Utils;
 
 sealed class SqliteConnectionPool : IAsyncDisposable {
-	public static async Task<SqliteConnectionPool> Create(SqliteConnectionStringBuilder connectionStringBuilder, int poolSize) {
+	public static async Task<SqliteConnectionPool> Create(SqliteConnectionStringFactory connectionStringFactory, int poolSize, ISqliteAttachedDatabaseCollector attachedDatabaseCollector) {
-		var pool = new SqliteConnectionPool(poolSize);
+		SqliteConnectionPool pool = new SqliteConnectionPool(poolSize, attachedDatabaseCollector);
-		await pool.InitializePooledConnections(connectionStringBuilder);
+		await pool.InitializePooledConnections(connectionStringFactory);
 		return pool;
 	}
 	
-	private static string GetConnectionString(SqliteConnectionStringBuilder connectionStringBuilder) {
+	private readonly ISqliteAttachedDatabaseCollector attachedDatabaseCollector;
-		connectionStringBuilder.Pooling = false;
-		return connectionStringBuilder.ToString();
-	}
 	
 	private readonly int poolSize;
 	private readonly List<PooledConnection> all;
@@ -27,24 +24,35 @@ sealed class SqliteConnectionPool : IAsyncDisposable {
 	private readonly CancellationTokenSource disposalTokenSource = new ();
 	private readonly CancellationToken disposalToken;
 	
-	private SqliteConnectionPool(int poolSize) {
+	private SqliteConnectionPool(int poolSize, ISqliteAttachedDatabaseCollector attachedDatabaseCollector) {
+		this.attachedDatabaseCollector = attachedDatabaseCollector;
+		
 		this.poolSize = poolSize;
 		this.all = new List<PooledConnection>(poolSize);
 		this.free = new ConcurrentPool<PooledConnection>(poolSize);
+		
 		this.disposalToken = disposalTokenSource.Token;
 	}
 	
-	private async Task InitializePooledConnections(SqliteConnectionStringBuilder connectionStringBuilder) {
+	private async Task InitializePooledConnections(SqliteConnectionStringFactory connectionStringFactory) {
-		string connectionString = GetConnectionString(connectionStringBuilder);
+		string connectionString = connectionStringFactory.Create();
+		
+		List<AttachedDatabase> attachedDatabases = [];
 		
 		for (int i = 0; i < poolSize; i++) {
-			var conn = new SqliteConnection(connectionString);
+			SqliteConnection innerConnection = new SqliteConnection(connectionString);
-			conn.Open();
+			await innerConnection.OpenAsync(disposalToken);
 			
-			var pooledConnection = new PooledConnection(this, conn);
+			PooledConnection pooledConnection = new PooledConnection(this, connectionStringFactory, innerConnection);
+			await pooledConnection.Setup(disposalToken);
 			
-			await pooledConnection.ExecuteAsync("PRAGMA journal_mode=WAL", disposalToken);
+			if (i == 0) {
-			await pooledConnection.ExecuteAsync("PRAGMA foreign_keys=ON", disposalToken);
+				attachedDatabases = await attachedDatabaseCollector.GetAttachedDatabases(pooledConnection).ToListAsync(disposalToken);
+			}
+			
+			foreach (var attachedDatabase in attachedDatabases) {
+				await pooledConnection.AttachDatabase(attachedDatabase);
+			}
 			
 			all.Add(pooledConnection);
 			await free.Push(pooledConnection, disposalToken);
@@ -74,48 +82,8 @@ sealed class SqliteConnectionPool : IAsyncDisposable {
 		disposalTokenSource.Dispose();
 	}
 	
-	private sealed class PooledConnection(SqliteConnectionPool pool, SqliteConnection conn) : ISqliteConnection {
+	private sealed class PooledConnection(SqliteConnectionPool pool, SqliteConnectionStringFactory connectionStringFactory, SqliteConnection innerConnection) : CustomSqliteConnection(connectionStringFactory, innerConnection) {
-		public SqliteConnection InnerConnection { get; } = conn;
+		private protected override async ValueTask DisposeConnection() {
-		
-		private DbTransaction? activeTransaction;
-		
-		public async Task BeginTransactionAsync() {
-			if (activeTransaction != null) {
-				throw new InvalidOperationException("A transaction is already active.");
-			}
-			
-			activeTransaction = await InnerConnection.BeginTransactionAsync();
-		}
-		
-		public async Task CommitTransactionAsync() {
-			if (activeTransaction == null) {
-				throw new InvalidOperationException("No active transaction to commit.");
-			}
-			
-			await activeTransaction.CommitAsync();
-			await activeTransaction.DisposeAsync();
-			activeTransaction = null;
-		}
-		
-		public async Task RollbackTransactionAsync() {
-			if (activeTransaction == null) {
-				throw new InvalidOperationException("No active transaction to rollback.");
-			}
-			
-			await activeTransaction.RollbackAsync();
-			await activeTransaction.DisposeAsync();
-			activeTransaction = null;
-		}
-		
-		public void AssignActiveTransaction(SqliteCommand command) {
-			command.Transaction = (SqliteTransaction?) activeTransaction;
-		}
-		
-		public async ValueTask DisposeAsync() {
-			if (activeTransaction != null) {
-				await RollbackTransactionAsync();
-			}
-			
 			await pool.Return(this);
 		}
 	}

app/Server/Database/Sqlite/Utils/SqliteConnectionStringFactory.cs

@@ -0,0 +1,15 @@
+using Microsoft.Data.Sqlite;
+
+namespace DHT.Server.Database.Sqlite.Utils;
+
+sealed record SqliteConnectionStringFactory(string Path) {
+	public string Create() {
+		var builder = new SqliteConnectionStringBuilder {
+			DataSource = Path,
+			Mode = SqliteOpenMode.ReadWriteCreate,
+			Pooling = false,
+		};
+		
+		return builder.ToString();
+	}
+}

app/Server/Database/Sqlite/Utils/SqliteExtensions.cs

@@ -30,7 +30,7 @@ static class SqliteExtensions {
 		return (long) (await command.ExecuteScalarAsync())!;
 	}
 	
-	public static SqliteCommand Insert(this ISqliteConnection conn, string tableName, (string Name, SqliteType Type)[] columns) {
+	public static SqliteCommand Insert(this ISqliteConnection conn, [LanguageInjection("sql", Prefix = "SELECT * FROM ")] string tableName, (string Name, SqliteType Type)[] columns) {
 		string columnNames = string.Join(separator: ',', columns.Select(static c => c.Name));
 		string columnParams = string.Join(separator: ',', columns.Select(static c => ':' + c.Name));
 		
@@ -41,7 +41,7 @@ static class SqliteExtensions {
 		return cmd;
 	}
 	
-	public static SqliteCommand Upsert(this ISqliteConnection conn, string tableName, (string Name, SqliteType Type)[] columns) {
+	public static SqliteCommand Upsert(this ISqliteConnection conn, [LanguageInjection("sql", Prefix = "SELECT * FROM ")] string tableName, (string Name, SqliteType Type)[] columns) {
 		string columnNames = string.Join(separator: ',', columns.Select(static c => c.Name));
 		string columnParams = string.Join(separator: ',', columns.Select(static c => ':' + c.Name));
 		string columnUpdates = string.Join(separator: ',', columns.Skip(1).Select(static c => c.Name + " = excluded." + c.Name));
@@ -55,7 +55,7 @@ static class SqliteExtensions {
 		return cmd;
 	}
 	
-	public static SqliteCommand Delete(this ISqliteConnection conn, string tableName, (string Name, SqliteType Type) column) {
+	public static SqliteCommand Delete(this ISqliteConnection conn, [LanguageInjection("sql", Prefix = "SELECT * FROM ")] string tableName, (string Name, SqliteType Type) column) {
 		var cmd = conn.Command("DELETE FROM " + tableName + " WHERE " + column.Name + " = :" + column.Name);
 		CreateParameters(cmd, [column]);
 		return cmd;

app/Server/Download/DownloadExporter.cs

@@ -0,0 +1,152 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.RegularExpressions;
+using System.Threading;
+using System.Threading.Channels;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+using DHT.Server.Data.Filters;
+using DHT.Server.Database;
+using DHT.Utils.Logging;
+using DHT.Utils.Tasks;
+using Channel = System.Threading.Channels.Channel;
+
+namespace DHT.Server.Download;
+
+public sealed partial class DownloadExporter(IDatabaseFile db, string folderPath) {
+	private static readonly Log Log = Log.ForType<DownloadExporter>();
+	
+	private const int Concurrency = 3;
+	
+	private static Channel<Data.Download> CreateExportChannel() {
+		return Channel.CreateBounded<Data.Download>(new BoundedChannelOptions(Concurrency * 4) {
+			SingleWriter = true,
+			SingleReader = false,
+			AllowSynchronousContinuations = true,
+			FullMode = BoundedChannelFullMode.Wait,
+		});
+	}
+	
+	public interface IProgressReporter {
+		Task ReportProgress(long processedCount, long totalCount);
+	}
+	
+	public readonly record struct Result(long SuccessfulCount, long FailedCount) {
+		internal static Result Combine(Result left, Result right) {
+			return new Result(left.SuccessfulCount + right.SuccessfulCount, left.FailedCount + right.FailedCount);
+		}
+	}
+	
+	public async Task<Result> Export(IProgressReporter reporter) {
+		DownloadItemFilter filter = new DownloadItemFilter {
+			IncludeStatuses = [DownloadStatus.Success]
+		};
+		
+		long totalCount = await db.Downloads.Count(filter);
+		
+		Channel<Data.Download> channel = CreateExportChannel();
+		ExportRunner exportRunner = new ExportRunner(db, folderPath, channel.Reader, reporter, totalCount);
+		
+		using CancellableTask progressTask = CancellableTask.Run(exportRunner.RunReportTask);
+		
+		List<Task<Result>> readerTasks = [];
+		for (int reader = 0; reader < Concurrency; reader++) {
+			readerTasks.Add(Task.Run(exportRunner.RunExportTask, CancellationToken.None));
+		}
+		
+		await foreach (Data.Download download in db.Downloads.Get(filter).WithCancellation(CancellationToken.None)) {
+			await channel.Writer.WriteAsync(download, CancellationToken.None);
+		}
+		
+		channel.Writer.Complete();
+		
+		Result result = (await Task.WhenAll(readerTasks)).Aggregate(Result.Combine);
+		
+		progressTask.Cancel();
+		await progressTask.Task;
+		
+		return result;
+	}
+	
+	private sealed partial class ExportRunner(IDatabaseFile db, string folderPath, ChannelReader<Data.Download> reader, IProgressReporter reporter, long totalCount) {
+		private long processedCount;
+		
+		public async Task RunReportTask(CancellationToken cancellationToken) {
+			try {
+				while (true) {
+					await reporter.ReportProgress(processedCount, totalCount);
+					await Task.Delay(TimeSpan.FromMilliseconds(25), cancellationToken);
+				}
+			} catch (OperationCanceledException) {
+				await reporter.ReportProgress(processedCount, totalCount);
+			}
+		}
+		
+		public async Task<Result> RunExportTask() {
+			long successfulCount = 0L;
+			long failedCount = 0L;
+			
+			await foreach (Data.Download download in reader.ReadAllAsync()) {
+				bool success;
+				try {
+					success = await db.Downloads.GetDownloadData(download.NormalizedUrl, stream => CopyToFile(download.NormalizedUrl, stream));
+				} catch (FileAlreadyExistsException) {
+					success = false;
+				} catch (Exception e) {
+					Log.Error("Could not export downloaded file: " + download.NormalizedUrl, e);
+					success = false;
+				}
+				
+				if (success) {
+					++successfulCount;
+				}
+				else {
+					++failedCount;
+				}
+				
+				Interlocked.Increment(ref processedCount);
+			}
+			
+			return new Result(successfulCount, failedCount);
+		}
+		
+		private async Task CopyToFile(string normalizedUrl, Stream blobStream) {
+			string fileName = UrlToFileName(normalizedUrl);
+			string filePath = Path.Combine(folderPath, fileName);
+			
+			if (File.Exists(filePath)) {
+				Log.Error("Skipping existing file: " + fileName);
+				throw FileAlreadyExistsException.Instance;
+			}
+			
+			await using var fileStream = new FileStream(filePath, FileMode.CreateNew, FileAccess.Write, FileShare.Read);
+			await blobStream.CopyToAsync(fileStream);
+		}
+		
+		[GeneratedRegex("[^a-zA-Z0-9_.-]")]
+		private static partial Regex DisallowedFileNameCharactersRegex();
+		
+		private static string UrlToFileName(string url) {
+			static string UriToFileName(Uri uri) {
+				string fileName = uri.AbsolutePath.TrimStart('/');
+				
+				if (uri.Query.Length > 0) {
+					int periodIndex = fileName.LastIndexOf('.');
+					return fileName.Insert(periodIndex == -1 ? fileName.Length : periodIndex, uri.Query.TrimEnd('&'));
+				}
+				else {
+					return fileName;
+				}
+			}
+			
+			string fileName = Uri.TryCreate(url, UriKind.Absolute, out var uri) ? UriToFileName(uri) : url;
+			return DisallowedFileNameCharactersRegex().Replace(fileName, "_");
+		}
+	}
+	
+	private sealed class FileAlreadyExistsException : Exception {
+		public static FileAlreadyExistsException Instance { get; } = new ();
+	}
+}

app/Server/Download/DownloadItem.cs

@@ -4,12 +4,7 @@ using DHT.Server.Data;
 
 namespace DHT.Server.Download;
 
-public readonly struct DownloadItem {
+public sealed record DownloadItem(string NormalizedUrl, string DownloadUrl, string? Type, ulong? Size) {
-	public string NormalizedUrl { get; init; }
-	public string DownloadUrl { get; init; }
-	public string? Type { get; init; }
-	public ulong? Size { get; init; }
-	
 	internal Data.Download ToSuccess(long size) {
 		return new Data.Download(NormalizedUrl, DownloadUrl, DownloadStatus.Success, Type, (ulong) Math.Max(size, val2: 0));
 	}

app/Server/Download/DownloadLinkExtractor.cs

@@ -12,30 +12,28 @@ namespace DHT.Server.Download;
 static class DownloadLinkExtractor {
 	private static readonly Log Log = Log.ForType(typeof(DownloadLinkExtractor));
 	
-	public static Data.Download FromUserAvatar(ulong userId, string avatarPath) {
+	public static FileUrl? ServerIcon(ServerType? type, ulong id, string iconHash) {
-		string url = $"https://cdn.discordapp.com/avatars/{userId}/{avatarPath}.webp";
+		return type switch {
-		return new Data.Download(url, url, DownloadStatus.Pending, MediaTypeNames.Image.Webp, size: null);
+			ServerType.Server => new FileUrl($"https://cdn.discordapp.com/icons/{id}/{iconHash}.webp", MediaTypeNames.Image.Webp),
+			ServerType.Group  => new FileUrl($"https://cdn.discordapp.com/channel-icons/{id}/{iconHash}.webp", MediaTypeNames.Image.Webp),
+			_                 => null,
+		};
 	}
 	
-	public static Data.Download FromEmoji(ulong emojiId, EmojiFlags flags) {
+	public static FileUrl UserAvatar(ulong id, string avatarHash) {
+		return new FileUrl($"https://cdn.discordapp.com/avatars/{id}/{avatarHash}.webp", MediaTypeNames.Image.Webp);
+	}
+	
+	public static FileUrl Emoji(ulong emojiId, EmojiFlags flags) {
 		bool isAnimated = flags.HasFlag(EmojiFlags.Animated);
 		
 		string ext = isAnimated ? "gif" : "webp";
 		string type = isAnimated ? MediaTypeNames.Image.Gif : MediaTypeNames.Image.Webp;
 		
-		string url = $"https://cdn.discordapp.com/emojis/{emojiId}.{ext}";
+		return new FileUrl($"https://cdn.discordapp.com/emojis/{emojiId}.{ext}", type);
-		return new Data.Download(url, url, DownloadStatus.Pending, type, size: null);
 	}
 	
-	public static Data.Download FromAttachment(Attachment attachment) {
+	public static async Task<FileUrl?> TryFromEmbedJson(Stream jsonStream) {
-		return FromAttachment(attachment.NormalizedUrl, attachment.DownloadUrl, attachment.Type, attachment.Size);
-	}
-	
-	public static Data.Download FromAttachment(string normalizedUrl, string downloadUrl, string? type, ulong size) {
-		return new Data.Download(normalizedUrl, downloadUrl, DownloadStatus.Pending, type, size);
-	}
-	
-	public static async Task<Data.Download?> TryFromEmbedJson(Stream jsonStream) {
 		try {
 			return FromEmbed(await JsonSerializer.DeserializeAsync(jsonStream, DiscordEmbedJsonContext.Default.DiscordEmbedJson));
 		} catch (Exception e) {
@@ -44,7 +42,7 @@ static class DownloadLinkExtractor {
 		}
 	}
 	
-	public static Data.Download? TryFromEmbedJson(string json) {
+	public static FileUrl? TryFromEmbedJson(string json) {
 		try {
 			return FromEmbed(JsonSerializer.Deserialize(json, DiscordEmbedJsonContext.Default.DiscordEmbedJson));
 		} catch (Exception e) {
@@ -53,21 +51,17 @@ static class DownloadLinkExtractor {
 		}
 	}
 	
-	private static Data.Download? FromEmbed(DiscordEmbedJson? embed) {
+	private static FileUrl? FromEmbed(DiscordEmbedJson? embed) {
-		if (embed is { Type: "image", Image.Url: {} imageUrl }) {
+		return embed switch {
-			return FromEmbedImage(imageUrl);
+			{ Type: "image", Image.Url: {} imageUrl } => FromEmbedImage(imageUrl),
-		}
+			{ Type: "video", Video.Url: {} videoUrl } => FromEmbedVideo(videoUrl),
-		else if (embed is { Type: "video", Video.Url: {} videoUrl }) {
+			_                                         => null,
-			return FromEmbedVideo(videoUrl);
+		};
-		}
-		else {
-			return null;
-		}
 	}
 	
-	private static Data.Download? FromEmbedImage(string url) {
+	private static FileUrl? FromEmbedImage(string url) {
 		if (DiscordCdn.NormalizeUrlAndReturnIfCdn(url, out string normalizedUrl)) {
-			return new Data.Download(normalizedUrl, url, DownloadStatus.Pending, GuessImageType(normalizedUrl), size: null);
+			return new FileUrl(normalizedUrl, url, GuessImageType(normalizedUrl));
 		}
 		else {
 			Log.Debug("Skipping non-CDN image url: " + url);
@@ -75,9 +69,9 @@ static class DownloadLinkExtractor {
 		}
 	}
 	
-	private static Data.Download? FromEmbedVideo(string url) {
+	private static FileUrl? FromEmbedVideo(string url) {
 		if (DiscordCdn.NormalizeUrlAndReturnIfCdn(url, out string normalizedUrl)) {
-			return new Data.Download(normalizedUrl, url, DownloadStatus.Pending, GuessVideoType(normalizedUrl), size: null);
+			return new FileUrl(normalizedUrl, url, GuessVideoType(normalizedUrl));
 		}
 		else {
 			Log.Debug("Skipping non-CDN video url: " + url);

app/Server/Download/Downloader.cs

@@ -1,8 +1,8 @@
-using System;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Data.Filters;
 using DHT.Server.Database;
+using DHT.Utils.Observables;
 
 namespace DHT.Server.Download;
 
@@ -19,11 +19,11 @@ public sealed class Downloader {
 		this.concurrentDownloads = concurrentDownloads;
 	}
 	
-	public async Task<IObservable<DownloadItem>> Start(DownloadItemFilter filter) {
+	public async Task<ObservableValue<DownloadItem>> Start(DownloadItemFilter filter) {
 		await semaphore.WaitAsync();
 		try {
 			current ??= new DownloaderTask(db, filter, concurrentDownloads);
-			return current.FinishedItems;
+			return current.LastFinishedItem;
 		} finally {
 			semaphore.Release();
 		}