Add channel & user filters to the app

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

@@ -8,6 +8,7 @@
         <entry key="Desktop/Dialogs/MessageDialog.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Dialogs/ProgressDialog.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/AboutWindow.axaml" value="Desktop/Desktop.csproj" />
+        <entry key="Desktop/Main/Controls/FilterPanel.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/Controls/StatusBar.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/MainContentScreen.axaml" value="Desktop/Desktop.csproj" />
         <entry key="Desktop/Main/MainWindow.axaml" value="Desktop/Desktop.csproj" />

app/Desktop/Main/Controls/FilterPanel.axaml

@@ -0,0 +1,60 @@
+<UserControl 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:controls="clr-namespace:DHT.Desktop.Main.Controls"
+             mc:Ignorable="d"
+             x:Class="DHT.Desktop.Main.Controls.FilterPanel">
+
+    <Design.DataContext>
+        <controls:FilterPanelModel />
+    </Design.DataContext>
+
+    <UserControl.Styles>
+        <Style Selector="WrapPanel">
+            <Setter Property="Background" Value="#FFFFFF" />
+        </Style>
+        <Style Selector="WrapPanel > StackPanel">
+            <Setter Property="Margin" Value="0 20 40 0" />
+            <Setter Property="Spacing" Value="4" />
+        </Style>
+        <Style Selector="Grid > Label">
+            <Setter Property="VerticalAlignment" Value="Center" />
+        </Style>
+        <Style Selector="Grid > CalendarDatePicker">
+            <Setter Property="CornerRadius" Value="0" />
+            <Setter Property="HorizontalAlignment" Value="Stretch" />
+            <Setter Property="HorizontalContentAlignment" Value="Center" />
+            <Setter Property="VerticalAlignment" Value="Center" />
+            <Setter Property="VerticalContentAlignment" Value="Center" />
+            <Setter Property="IsTodayHighlighted" Value="True" />
+            <Setter Property="SelectedDateFormat" Value="Short" />
+        </Style>
+        <Style Selector="Button">
+            <Setter Property="Margin" Value="0 0 0 8" />
+        </Style>
+    </UserControl.Styles>
+
+    <WrapPanel>
+        <StackPanel>
+            <CheckBox IsChecked="{Binding FilterByDate}">Filter by Date</CheckBox>
+            <Grid ColumnDefinitions="Auto, 4, 140" RowDefinitions="Auto, 4, Auto" Margin="4 0">
+                <Label Grid.Row="0" Grid.Column="0">From:</Label>
+                <CalendarDatePicker Grid.Row="0" Grid.Column="2" x:Name="StartDatePicker" IsEnabled="{Binding FilterByDate}" SelectedDateChanged="CalendarDatePicker_OnSelectedDateChanged" />
+                <Label Grid.Row="2" Grid.Column="0">To:</Label>
+                <CalendarDatePicker Grid.Row="2" Grid.Column="2" x:Name="EndDatePicker" IsEnabled="{Binding FilterByDate}" SelectedDateChanged="CalendarDatePicker_OnSelectedDateChanged" />
+            </Grid>
+        </StackPanel>
+        <StackPanel>
+            <CheckBox IsChecked="{Binding FilterByChannel}">Filter by Channel</CheckBox>
+            <Button Command="{Binding OpenChannelFilterDialog}" IsEnabled="{Binding FilterByChannel}">Select Channels...</Button>
+            <TextBlock Text="{Binding ChannelFilterLabel}" />
+        </StackPanel>
+        <StackPanel>
+            <CheckBox IsChecked="{Binding FilterByUser}">Filter by User</CheckBox>
+            <Button Command="{Binding OpenUserFilterDialog}" IsEnabled="{Binding FilterByUser}">Select Users...</Button>
+            <TextBlock Text="{Binding UserFilterLabel}" />
+        </StackPanel>
+    </WrapPanel>
+
+</UserControl>

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

@@ -0,0 +1,21 @@
+using Avalonia.Controls;
+using Avalonia.Markup.Xaml;
+
+namespace DHT.Desktop.Main.Controls {
+	public class FilterPanel : UserControl {
+		public FilterPanel() {
+			InitializeComponent();
+		}
+
+		private void InitializeComponent() {
+			AvaloniaXamlLoader.Load(this);
+		}
+
+		public void CalendarDatePicker_OnSelectedDateChanged(object? sender, SelectionChangedEventArgs e) {
+			if (DataContext is FilterPanelModel model) {
+				model.StartDate = this.FindControl<CalendarDatePicker>("StartDatePicker").SelectedDate;
+				model.EndDate = this.FindControl<CalendarDatePicker>("EndDatePicker").SelectedDate;
+			}
+		}
+	}
+}

app/Desktop/Main/Controls/FilterPanelModel.cs

@@ -0,0 +1,234 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Avalonia.Controls;
+using DHT.Desktop.Dialogs;
+using DHT.Desktop.Models;
+using DHT.Server.Data;
+using DHT.Server.Data.Filters;
+using DHT.Server.Database;
+
+namespace DHT.Desktop.Main.Controls {
+	public class FilterPanelModel : BaseModel {
+		private static readonly HashSet<string> FilterProperties = new () {
+			nameof(FilterByDate),
+			nameof(StartDate),
+			nameof(EndDate),
+			nameof(FilterByChannel),
+			nameof(IncludedChannels),
+			nameof(FilterByUser),
+			nameof(IncludedUsers)
+		};
+
+		public event PropertyChangedEventHandler? FilterPropertyChanged;
+
+		private bool filterByDate = false;
+		private DateTime? startDate = null;
+		private DateTime? endDate = null;
+		private bool filterByChannel = false;
+		private HashSet<ulong>? includedChannels = null;
+		private bool filterByUser = false;
+		private HashSet<ulong>? includedUsers = null;
+
+		public bool FilterByDate {
+			get => filterByDate;
+			set => Change(ref filterByDate, value);
+		}
+
+		public DateTime? StartDate {
+			get => startDate;
+			set => Change(ref startDate, value);
+		}
+
+		public DateTime? EndDate {
+			get => endDate;
+			set => Change(ref endDate, value);
+		}
+
+		public bool FilterByChannel {
+			get => filterByChannel;
+			set => Change(ref filterByChannel, value);
+		}
+
+		public HashSet<ulong> IncludedChannels {
+			get => includedChannels ?? db.GetAllChannels().Select(channel => channel.Id).ToHashSet();
+			set => Change(ref includedChannels, value);
+		}
+
+		public bool FilterByUser {
+			get => filterByUser;
+			set => Change(ref filterByUser, value);
+		}
+
+
+		public HashSet<ulong> IncludedUsers {
+			get => includedUsers ?? db.GetAllUsers().Select(user => user.Id).ToHashSet();
+			set => Change(ref includedUsers, value);
+		}
+
+		private string channelFilterLabel = "";
+
+		public string ChannelFilterLabel {
+			get => channelFilterLabel;
+			set => Change(ref channelFilterLabel, value);
+		}
+
+		private string userFilterLabel = "";
+
+		public string UserFilterLabel {
+			get => userFilterLabel;
+			set => Change(ref userFilterLabel, value);
+		}
+
+		private readonly Window window;
+		private readonly IDatabaseFile db;
+
+		[Obsolete("Designer")]
+		public FilterPanelModel() : this(null!, DummyDatabaseFile.Instance) {}
+
+		public FilterPanelModel(Window window, IDatabaseFile db) {
+			this.window = window;
+			this.db = db;
+
+			UpdateChannelFilterLabel();
+			UpdateUserFilterLabel();
+
+			PropertyChanged += OnPropertyChanged;
+			db.Statistics.PropertyChanged += OnDbStatisticsChanged;
+		}
+
+		private void OnPropertyChanged(object? sender, PropertyChangedEventArgs e) {
+			if (e.PropertyName != null && FilterProperties.Contains(e.PropertyName)) {
+				FilterPropertyChanged?.Invoke(sender, e);
+			}
+
+			if (e.PropertyName is nameof(FilterByChannel) or nameof(IncludedChannels)) {
+				UpdateChannelFilterLabel();
+			}
+			else if (e.PropertyName is nameof(FilterByUser) or nameof(IncludedUsers)) {
+				UpdateUserFilterLabel();
+			}
+		}
+
+		private void OnDbStatisticsChanged(object? sender, PropertyChangedEventArgs e) {
+			if (e.PropertyName == nameof(DatabaseStatistics.TotalChannels)) {
+				UpdateChannelFilterLabel();
+			}
+			else if (e.PropertyName == nameof(DatabaseStatistics.TotalUsers)) {
+				UpdateUserFilterLabel();
+			}
+		}
+
+		public async void OpenChannelFilterDialog() {
+			var servers = db.GetAllServers().ToDictionary(server => server.Id);
+			var items = new List<CheckBoxItem<ulong>>();
+			var included = IncludedChannels;
+
+			foreach (var channel in db.GetAllChannels()) {
+				var channelId = channel.Id;
+				var channelName = channel.Name;
+
+				string title;
+				if (servers.TryGetValue(channel.Server, out var server)) {
+					var titleBuilder = new StringBuilder();
+					var 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();
+				}
+				else {
+					title = channelName;
+				}
+
+				items.Add(new CheckBoxItem<ulong>(channelId) {
+					Title = title,
+					Checked = included.Contains(channelId)
+				});
+			}
+
+			var result = await OpenIdFilterDialog(window, "Included Channels", items);
+			if (result != null) {
+				IncludedChannels = result;
+			}
+		}
+
+		public async void OpenUserFilterDialog() {
+			var items = new List<CheckBoxItem<ulong>>();
+			var included = IncludedUsers;
+
+			foreach (var user in db.GetAllUsers()) {
+				var name = user.Name;
+				var discriminator = user.Discriminator;
+
+				items.Add(new CheckBoxItem<ulong>(user.Id) {
+					Title = discriminator == null ? name : name + " #" + discriminator,
+					Checked = included.Contains(user.Id)
+				});
+			}
+
+			var result = await OpenIdFilterDialog(window, "Included Users", items);
+			if (result != null) {
+				IncludedUsers = result;
+			}
+		}
+
+		private void UpdateChannelFilterLabel() {
+			long total = db.Statistics.TotalChannels;
+			long included = FilterByChannel ? IncludedChannels.Count : total;
+			ChannelFilterLabel = "Selected " + included + " / " + total + (total == 1 ? " channel." : " channels.");
+		}
+
+		private void UpdateUserFilterLabel() {
+			long total = db.Statistics.TotalUsers;
+			long included = FilterByUser ? IncludedUsers.Count : total;
+			UserFilterLabel = "Selected " + included + " / " + total + (total == 1 ? " user." : " users.");
+		}
+
+		public MessageFilter CreateFilter() {
+			MessageFilter filter = new();
+
+			if (FilterByDate) {
+				filter.StartDate = StartDate;
+				filter.EndDate = EndDate;
+			}
+
+			if (FilterByChannel) {
+				filter.ChannelIds = new HashSet<ulong>(IncludedChannels);
+			}
+
+			if (FilterByUser) {
+				filter.UserIds = new HashSet<ulong>(IncludedUsers);
+			}
+
+			return filter;
+		}
+
+		private static async Task<HashSet<ulong>?> OpenIdFilterDialog(Window window, string title, List<CheckBoxItem<ulong>> items) {
+			items.Sort((item1, item2) => item1.Title.CompareTo(item2.Title));
+
+			var model = new CheckBoxDialogModel<ulong>(items) {
+				Title = title
+			};
+
+			var dialog = new CheckBoxDialog { DataContext = model };
+			var result = await dialog.ShowDialog<DialogResult.OkCancel>(window);
+
+			return result == DialogResult.OkCancel.Ok ? model.SelectedItems.Select(item => item.Item).ToHashSet() : null;
+		}
+	}
+}

app/Desktop/Main/Pages/ViewerPage.axaml

@@ -3,6 +3,7 @@
              xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              xmlns:pages="clr-namespace:DHT.Desktop.Main.Pages"
+             xmlns:controls="clr-namespace:DHT.Desktop.Main.Controls"
              mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
              x:Class="DHT.Desktop.Main.Pages.ViewerPage">
 
@@ -10,36 +11,13 @@
         <pages:ViewerPageModel />
     </Design.DataContext>
 
-    <UserControl.Styles>
+    <StackPanel Orientation="Vertical">
-        <Style Selector="Grid > Label">
-            <Setter Property="VerticalAlignment" Value="Center" />
-        </Style>
-        <Style Selector="Grid > CalendarDatePicker">
-            <Setter Property="CornerRadius" Value="0" />
-            <Setter Property="HorizontalAlignment" Value="Stretch" />
-            <Setter Property="HorizontalContentAlignment" Value="Center" />
-            <Setter Property="VerticalAlignment" Value="Center" />
-            <Setter Property="VerticalContentAlignment" Value="Center" />
-            <Setter Property="IsTodayHighlighted" Value="True" />
-            <Setter Property="SelectedDateFormat" Value="Short" />
-        </Style>
-    </UserControl.Styles>
-
-    <StackPanel Orientation="Vertical" Spacing="20">
         <StackPanel Orientation="Horizontal" VerticalAlignment="Top">
             <Button Command="{Binding OnClickOpenViewer}" Margin="0 0 5 0">Open Viewer</Button>
             <Button Command="{Binding OnClickSaveViewer}" Margin="5 0 0 0">Save Viewer</Button>
         </StackPanel>
-        <TextBlock Text="{Binding ExportedMessageText}" />
+        <TextBlock Text="{Binding ExportedMessageText}" Margin="0 20 0 0" />
-        <StackPanel>
+        <controls:FilterPanel DataContext="{Binding FilterModel}" />
-            <CheckBox IsChecked="{Binding FilterByDate}">Filter by Date</CheckBox>
-            <Grid ColumnDefinitions="Auto, 4, 140" RowDefinitions="Auto, 4, Auto" Margin="4">
-                <Label Grid.Row="0" Grid.Column="0">From:</Label>
-                <CalendarDatePicker Grid.Row="0" Grid.Column="2" x:Name="StartDatePicker" IsEnabled="{Binding FilterByDate}" SelectedDateChanged="CalendarDatePicker_OnSelectedDateChanged" />
-                <Label Grid.Row="2" Grid.Column="0">To:</Label>
-                <CalendarDatePicker Grid.Row="2" Grid.Column="2" x:Name="EndDatePicker" IsEnabled="{Binding FilterByDate}" SelectedDateChanged="CalendarDatePicker_OnSelectedDateChanged" />
-            </Grid>
-        </StackPanel>
     </StackPanel>
 
 </UserControl>

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

@@ -10,12 +10,5 @@ namespace DHT.Desktop.Main.Pages {
 		private void InitializeComponent() {
 			AvaloniaXamlLoader.Load(this);
 		}
-
-		public void CalendarDatePicker_OnSelectedDateChanged(object? sender, SelectionChangedEventArgs e) {
-			if (DataContext is ViewerPageModel model) {
-				model.StartDate = this.FindControl<CalendarDatePicker>("StartDatePicker").SelectedDate;
-				model.EndDate = this.FindControl<CalendarDatePicker>("EndDatePicker").SelectedDate;
-			}
-		}
 	}
 }

app/Desktop/Main/Pages/ViewerPageModel.cs

@@ -6,9 +6,9 @@ using System.IO;
 using System.Threading.Tasks;
 using System.Web;
 using Avalonia.Controls;
+using DHT.Desktop.Main.Controls;
 using DHT.Desktop.Models;
 using DHT.Desktop.Resources;
-using DHT.Server.Data.Filters;
 using DHT.Server.Database;
 using DHT.Server.Database.Export;
 
@@ -16,26 +16,7 @@ namespace DHT.Desktop.Main.Pages {
 	public class ViewerPageModel : BaseModel {
 		public string ExportedMessageText { get; private set; } = "";
 
-		private bool filterByDate = false;
+		private FilterPanelModel FilterModel { get; }
-
-		public bool FilterByDate {
-			get => filterByDate;
-			set => Change(ref filterByDate, value);
-		}
-
-		private DateTime? startDate = null;
-
-		public DateTime? StartDate {
-			get => startDate;
-			set => Change(ref startDate, value);
-		}
-
-		private DateTime? endDate = null;
-
-		public DateTime? EndDate {
-			get => endDate;
-			set => Change(ref endDate, value);
-		}
 
 		private readonly Window window;
 		private readonly IDatabaseFile db;
@@ -47,15 +28,14 @@ namespace DHT.Desktop.Main.Pages {
 			this.window = window;
 			this.db = db;
 
-			this.PropertyChanged += OnPropertyChanged;
+			this.FilterModel = new FilterPanelModel(window, db);
+			this.FilterModel.FilterPropertyChanged += OnFilterPropertyChanged;
 			this.db.Statistics.PropertyChanged += OnDbStatisticsChanged;
 			UpdateStatistics();
 		}
 
-		private void OnPropertyChanged(object? sender, PropertyChangedEventArgs e) {
+		private void OnFilterPropertyChanged(object? sender, PropertyChangedEventArgs e) {
-			if (e.PropertyName is nameof(FilterByDate) or nameof(StartDate) or nameof(EndDate)) {
+			UpdateStatistics();
-				UpdateStatistics();
-			}
 		}
 
 		private void OnDbStatisticsChanged(object? sender, PropertyChangedEventArgs e) {
@@ -64,24 +44,13 @@ namespace DHT.Desktop.Main.Pages {
 			}
 		}
 
-		private MessageFilter CreateFilter() {
-			MessageFilter filter = new();
-
-			if (FilterByDate) {
-				filter.StartDate = StartDate;
-				filter.EndDate = EndDate;
-			}
-
-			return filter;
-		}
-
 		private void UpdateStatistics() {
-			ExportedMessageText = "Will export " + db.CountMessages(CreateFilter()) + " out of " + db.Statistics.TotalMessages + " message(s).";
+			ExportedMessageText = "Will export " + db.CountMessages(FilterModel.CreateFilter()) + " out of " + db.Statistics.TotalMessages + " message(s).";
 			OnPropertyChanged(nameof(ExportedMessageText));
 		}
 
 		private async Task<string> GenerateViewerContents() {
-			string json = ViewerJsonExport.Generate(db, CreateFilter());
+			string json = ViewerJsonExport.Generate(db, FilterModel.CreateFilter());
 
 			string index = await ResourceLoader.ReadTextAsync("Viewer/index.html");
 			string viewer = index.Replace("/*[JS]*/", await ResourceLoader.ReadJoinedAsync("Viewer/scripts/", '\n'))

app/Server/Data/Filters/MessageFilter.cs

@@ -6,6 +6,8 @@ namespace DHT.Server.Data.Filters {
 		public DateTime? StartDate { get; set; }
 		public DateTime? EndDate { get; set; }
 
-		public HashSet<ulong> MessageIds { get; } = new();
+		public HashSet<ulong>? ChannelIds { get; set; } = null;
+		public HashSet<ulong>? UserIds { get; set; } = null;
+		public HashSet<ulong>? MessageIds { get; set; } = null;
 	}
 }

app/Server/Database/DatabaseStatistics.cs

@@ -5,6 +5,7 @@ namespace DHT.Server.Database {
 	public class DatabaseStatistics : INotifyPropertyChanged {
 		private long totalServers;
 		private long totalChannels;
+		private long totalUsers;
 		private long totalMessages;
 
 		public long TotalServers {
@@ -17,6 +18,11 @@ namespace DHT.Server.Database {
 			internal set => Change(out totalChannels, value);
 		}
 
+		public long TotalUsers {
+			get => totalUsers;
+			internal set => Change(out totalUsers, value);
+		}
+
 		public long TotalMessages {
 			get => totalMessages;
 			internal set => Change(out totalMessages, value);
@@ -33,6 +39,7 @@ namespace DHT.Server.Database {
 			return new DatabaseStatistics {
 				totalServers = totalServers,
 				totalChannels = totalChannels,
+				totalUsers = TotalUsers,
 				totalMessages = totalMessages
 			};
 		}

app/Server/Database/Export/ViewerJsonExport.cs

@@ -8,26 +8,48 @@ using DHT.Server.Data.Filters;
 namespace DHT.Server.Database.Export {
 	public static class ViewerJsonExport {
 		public static string Generate(IDatabaseFile db, MessageFilter? filter = null) {
-			JsonSerializerOptions opts = new();
+			var includedUserIds = new HashSet<ulong>();
+			var includedChannelIds = new HashSet<ulong>();
+			var includedServerIds = new HashSet<ulong>();
+
+			var includedMessages = db.GetMessages(filter);
+			var includedChannels = new List<Channel>();
+
+			foreach (var message in includedMessages) {
+				includedUserIds.Add(message.Sender);
+				includedChannelIds.Add(message.Channel);
+			}
+
+			foreach (var channel in db.GetAllChannels()) {
+				if (includedChannelIds.Contains(channel.Id)) {
+					includedChannels.Add(channel);
+					includedServerIds.Add(channel.Server);
+				}
+			}
+
+			var opts = new JsonSerializerOptions();
 			opts.Converters.Add(new ViewerJsonSnowflakeSerializer());
 
-			var users = GenerateUserList(db, out var userindex, out var userIndices);
+			var users = GenerateUserList(db, includedUserIds, out var userindex, out var userIndices);
-			var servers = GenerateServerList(db, out var serverindex);
+			var servers = GenerateServerList(db, includedServerIds, out var serverindex);
-			var channels = GenerateChannelList(db, serverindex);
+			var channels = GenerateChannelList(includedChannels, serverindex);
 
 			return JsonSerializer.Serialize(new {
 				meta = new { users, userindex, servers, channels },
-				data = GenerateMessageList(db, filter, userIndices)
+				data = GenerateMessageList(includedMessages, userIndices)
 			}, opts);
 		}
 
-		private static dynamic GenerateUserList(IDatabaseFile db, out List<string> userindex, out Dictionary<ulong, int> userIndices) {
+		private static dynamic GenerateUserList(IDatabaseFile db, HashSet<ulong> userIds, out List<string> userindex, out Dictionary<ulong, int> userIndices) {
 			var users = new Dictionary<string, dynamic>();
 			userindex = new List<string>();
 			userIndices = new Dictionary<ulong, int>();
 
 			foreach (var user in db.GetAllUsers()) {
-				var id = user.Id.ToString();
+				var id = user.Id;
+				if (!userIds.Contains(id)) {
+					continue;
+				}
 
 				dynamic obj = new ExpandoObject();
 				obj.name = user.Name;
@@ -40,20 +62,26 @@ namespace DHT.Server.Database.Export {
 					obj.tag = user.Discriminator;
 				}
 
-				userIndices[user.Id] = users.Count;
+				var idStr = id.ToString();
-				userindex.Add(id);
+				userIndices[id] = users.Count;
-				users[id] = obj;
+				userindex.Add(idStr);
+				users[idStr] = obj;
 			}
 
 			return users;
 		}
 
-		private static dynamic GenerateServerList(IDatabaseFile db, out Dictionary<ulong, int> serverIndices) {
+		private static dynamic GenerateServerList(IDatabaseFile db, HashSet<ulong> serverIds, out Dictionary<ulong, int> serverIndices) {
 			var servers = new List<dynamic>();
 			serverIndices = new Dictionary<ulong, int>();
 
 			foreach (var server in db.GetAllServers()) {
-				serverIndices[server.Id] = servers.Count;
+				var id = server.Id;
+				if (!serverIds.Contains(id)) {
+					continue;
+				}
+
+				serverIndices[id] = servers.Count;
 				servers.Add(new {
 					name = server.Name,
 					type = ServerTypes.ToJsonViewerString(server.Type)
@@ -63,10 +91,10 @@ namespace DHT.Server.Database.Export {
 			return servers;
 		}
 
-		private static dynamic GenerateChannelList(IDatabaseFile db, Dictionary<ulong, int> serverIndices) {
+		private static dynamic GenerateChannelList(List<Channel> includedChannels, Dictionary<ulong, int> serverIndices) {
 			var channels = new Dictionary<string, dynamic>();
 
-			foreach (var channel in db.GetAllChannels()) {
+			foreach (var channel in includedChannels) {
 				dynamic obj = new ExpandoObject();
 				obj.server = serverIndices[channel.Server];
 				obj.name = channel.Name;
@@ -93,10 +121,10 @@ namespace DHT.Server.Database.Export {
 			return channels;
 		}
 
-		private static dynamic GenerateMessageList(IDatabaseFile db, MessageFilter? filter, Dictionary<ulong, int> userIndices) {
+		private static dynamic GenerateMessageList(List<Message> includedMessages, Dictionary<ulong, int> userIndices) {
 			var data = new Dictionary<string, Dictionary<string, dynamic>>();
 
-			foreach (var grouping in db.GetMessages(filter).GroupBy(message => message.Channel)) {
+			foreach (var grouping in includedMessages.GroupBy(message => message.Channel)) {
 				var channel = grouping.Key.ToString();
 				var channelData = new Dictionary<string, dynamic>();
 

app/Server/Database/Sqlite/SqliteDatabaseFile.cs

@@ -32,6 +32,7 @@ namespace DHT.Server.Database.Sqlite {
 			this.Statistics = new DatabaseStatistics();
 			UpdateServerStatistics();
 			UpdateChannelStatistics();
+			UpdateUserStatistics();
 			UpdateMessageStatistics();
 		}
 
@@ -129,6 +130,7 @@ namespace DHT.Server.Database.Sqlite {
 			}
 
 			tx.Commit();
+			UpdateUserStatistics();
 		}
 
 		public List<User> GetAllUsers() {
@@ -369,6 +371,11 @@ namespace DHT.Server.Database.Sqlite {
 			Statistics.TotalChannels = cmd.ExecuteScalar() as long? ?? 0;
 		}
 
+		private void UpdateUserStatistics() {
+			using var cmd = conn.Command("SELECT COUNT(*) FROM users");
+			Statistics.TotalUsers = cmd.ExecuteScalar() as long? ?? 0;
+		}
+
 		private void UpdateMessageStatistics() {
 			using var cmd = conn.Command("SELECT COUNT(*) FROM messages");
 			Statistics.TotalMessages = cmd.ExecuteScalar() as long? ?? 0L;

app/Server/Database/Sqlite/SqliteMessageFilter.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using DHT.Server.Data.Filters;
 
 namespace DHT.Server.Database.Sqlite {
@@ -20,8 +19,16 @@ namespace DHT.Server.Database.Sqlite {
 				conditions.Add("timestamp <= " + new DateTimeOffset(filter.EndDate.Value).ToUnixTimeMilliseconds());
 			}
 
-			if (filter.MessageIds.Count > 0) {
+			if (filter.ChannelIds != null) {
-				conditions.Add("(" + string.Join(" OR ", filter.MessageIds.Select(id => "message_id = " + id)) + ")");
+				conditions.Add("channel_id IN (" + string.Join(",", filter.ChannelIds) + ")");
+			}
+
+			if (filter.UserIds != null) {
+				conditions.Add("sender_id IN (" + string.Join(",", filter.UserIds) + ")");
+			}
+
+			if (filter.MessageIds != null) {
+				conditions.Add("message_id IN (" + string.Join(",", filter.MessageIds) + ")");
 			}
 
 			return conditions.Count == 0 ? "" : " WHERE " + string.Join(" AND ", conditions);

app/Server/Endpoints/TrackMessagesEndpoint.cs

@@ -22,17 +22,19 @@ namespace DHT.Server.Endpoints {
 				throw new HttpException(HttpStatusCode.BadRequest, "Expected root element to be an array.");
 			}
 
-			var addedMessageIdFilter = new MessageFilter();
+			var addedMessageIds = new HashSet<ulong>();
 			var messages = new Message[root.GetArrayLength()];
 
 			int i = 0;
 			foreach (JsonElement ele in root.EnumerateArray()) {
 				var message = ReadMessage(ele, "message");
 				messages[i++] = message;
-				addedMessageIdFilter.MessageIds.Add(message.Id);
+				addedMessageIds.Add(message.Id);
 			}
 
-			bool anyNewMessages = Db.CountMessages(addedMessageIdFilter) < messages.Length;
+			var addedMessageFilter = new MessageFilter { MessageIds = addedMessageIds };
+			bool anyNewMessages = Db.CountMessages(addedMessageFilter) < messages.Length;
+
 			Db.AddMessages(messages);
 
 			return (HttpStatusCode.OK, anyNewMessages ? 1 : 0);