Add tools to remove/keep filtered messages in the app

app/Desktop/Main/Controls/FilterPanelModel.cs

@@ -26,6 +26,8 @@ namespace DHT.Desktop.Main.Controls {
 
 		public event PropertyChangedEventHandler? FilterPropertyChanged;
 
+		public bool HasAnyFilters => FilterByDate || FilterByChannel || FilterByUser;
+
 		private bool filterByDate = false;
 		private DateTime? startDate = null;
 		private DateTime? endDate = null;
@@ -64,7 +66,6 @@ namespace DHT.Desktop.Main.Controls {
 			set => Change(ref filterByUser, value);
 		}
 
-
 		public HashSet<ulong> IncludedUsers {
 			get => includedUsers ?? db.GetAllUsers().Select(user => user.Id).ToHashSet();
 			set => Change(ref includedUsers, value);

app/Desktop/Main/MainWindow.axaml

@@ -7,7 +7,7 @@
         x:Class="DHT.Desktop.Main.MainWindow"
         Title="Discord History Tracker"
         Icon="avares://DiscordHistoryTracker/Resources/icon.ico"
-        Width="800" Height="450"
+        Width="800" Height="500"
         MinWidth="480" MinHeight="240"
         WindowStartupLocation="CenterScreen">
 

app/Desktop/Main/Pages/ViewerPage.axaml

@@ -11,6 +11,12 @@
         <pages:ViewerPageModel />
     </Design.DataContext>
 
+    <UserControl.Styles>
+        <Style Selector="Expander">
+            <Setter Property="Margin" Value="0 25 0 0" />
+        </Style>
+    </UserControl.Styles>
+
     <StackPanel Orientation="Vertical">
         <StackPanel Orientation="Horizontal" VerticalAlignment="Top">
             <Button Command="{Binding OnClickOpenViewer}" Margin="0 0 5 0">Open Viewer</Button>
@@ -18,6 +24,15 @@
         </StackPanel>
         <TextBlock Text="{Binding ExportedMessageText}" Margin="0 20 0 0" />
         <controls:FilterPanel DataContext="{Binding FilterModel}" />
+        <Expander Header="Database Tools">
+            <StackPanel Orientation="Vertical" Spacing="10">
+                <StackPanel Orientation="Vertical" Spacing="4">
+                    <RadioButton GroupName="DatabaseToolFilterMode" IsEnabled="{Binding HasFilters}" IsChecked="{Binding DatabaseToolFilterModeKeep}">Keep Only Messages Matching Filters</RadioButton>
+                    <RadioButton GroupName="DatabaseToolFilterMode" IsEnabled="{Binding HasFilters}" IsChecked="{Binding DatabaseToolFilterModeRemove}">Remove Messages Matching Filters</RadioButton>
+                </StackPanel>
+                <Button IsEnabled="{Binding HasFilters}" Command="{Binding OnClickApplyFiltersToDatabase}">Apply Filters to Database</Button>
+            </StackPanel>
+        </Expander>
     </StackPanel>
 
 </UserControl>

app/Desktop/Main/Pages/ViewerPageModel.cs

@@ -7,9 +7,11 @@ using System.Threading.Tasks;
 using System.Web;
 using Avalonia.Controls;
 using DHT.Desktop.Common;
+using DHT.Desktop.Dialogs;
 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;
 
@@ -17,6 +19,16 @@ namespace DHT.Desktop.Main.Pages {
 	public class ViewerPageModel : BaseModel {
 		public string ExportedMessageText { get; private set; } = "";
 
+		public bool DatabaseToolFilterModeKeep { get; set; } = true;
+		public bool DatabaseToolFilterModeRemove { get; set; } = false;
+
+		private bool hasFilters = false;
+
+		public bool HasFilters {
+			get => hasFilters;
+			set => Change(ref hasFilters, value);
+		}
+
 		private FilterPanelModel FilterModel { get; }
 
 		private readonly Window window;
@@ -37,6 +49,7 @@ namespace DHT.Desktop.Main.Pages {
 
 		private void OnFilterPropertyChanged(object? sender, PropertyChangedEventArgs e) {
 			UpdateStatistics();
+			HasFilters = FilterModel.HasAnyFilters;
 		}
 
 		private void OnDbStatisticsChanged(object? sender, PropertyChangedEventArgs e) {
@@ -95,5 +108,20 @@ namespace DHT.Desktop.Main.Pages {
 				await File.WriteAllTextAsync(path, await GenerateViewerContents());
 			}
 		}
+
+		public async void OnClickApplyFiltersToDatabase() {
+			var filter = FilterModel.CreateFilter();
+
+			if (DatabaseToolFilterModeKeep) {
+				if (DialogResult.YesNo.Yes == await Dialog.ShowYesNo(window, "Keep Matching Messages in This Database", db.CountMessages(filter).Pluralize("message") + " will be kept, and the rest will be removed from this database. This action cannot be undone. Proceed?")) {
+					db.RemoveMessages(filter, MessageFilterRemovalMode.KeepMatching);
+				}
+			}
+			else if (DatabaseToolFilterModeRemove) {
+				if (DialogResult.YesNo.Yes == await Dialog.ShowYesNo(window, "Remove Matching Messages in This Database", db.CountMessages(filter).Pluralize("message") + " will be removed from this database. This action cannot be undone. Proceed?")) {
+					db.RemoveMessages(filter, MessageFilterRemovalMode.RemoveMatching);
+				}
+			}
+		}
 	}
 }

app/Server/Data/Filters/MessageFilterRemovalMode.cs

@@ -0,0 +1,6 @@
+namespace DHT.Server.Data.Filters {
+	public enum MessageFilterRemovalMode {
+		KeepMatching,
+		RemoveMatching
+	}
+}

app/Server/Database/DummyDatabaseFile.cs

@@ -40,6 +40,8 @@ namespace DHT.Server.Database {
 			return new();
 		}
 
+		public void RemoveMessages(MessageFilter filter, MessageFilterRemovalMode mode) {}
+
 		public void Dispose() {
 			GC.SuppressFinalize(this);
 		}

app/Server/Database/IDatabaseFile.cs

@@ -20,5 +20,6 @@ namespace DHT.Server.Database {
 		void AddMessages(Message[] messages);
 		int CountMessages(MessageFilter? filter = null);
 		List<Message> GetMessages(MessageFilter? filter = null);
+		void RemoveMessages(MessageFilter filter, MessageFilterRemovalMode mode);
 	}
 }

app/Server/Database/Sqlite/SqliteDatabaseFile.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Text;
 using System.Threading.Tasks;
 using DHT.Server.Collections;
 using DHT.Server.Data;
@@ -303,6 +304,24 @@ namespace DHT.Server.Database.Sqlite {
 			return list;
 		}
 
+		public void RemoveMessages(MessageFilter filter, MessageFilterRemovalMode mode) {
+			var whereClause = filter.GenerateWhereClause(invert: mode == MessageFilterRemovalMode.KeepMatching);
+			if (string.IsNullOrEmpty(whereClause)) {
+				return;
+			}
+
+			// Rider is being stupid...
+			StringBuilder build = new StringBuilder()
+			                      .Append("DELETE ")
+			                      .Append("FROM messages")
+			                      .Append(whereClause);
+
+			using var cmd = conn.Command(build.ToString());
+			cmd.ExecuteNonQuery();
+
+			UpdateMessageStatistics();
+		}
+
 		private MultiDictionary<ulong, Attachment> GetAllAttachments() {
 			var dict = new MultiDictionary<ulong, Attachment>();
 

app/Server/Database/Sqlite/SqliteMessageFilter.cs

@@ -4,7 +4,7 @@ using DHT.Server.Data.Filters;
 
 namespace DHT.Server.Database.Sqlite {
 	public static class SqliteMessageFilter {
-		public static string GenerateWhereClause(this MessageFilter? filter) {
+		public static string GenerateWhereClause(this MessageFilter? filter, bool invert = false) {
 			if (filter == null) {
 				return "";
 			}
@@ -31,7 +31,16 @@ namespace DHT.Server.Database.Sqlite {
 				conditions.Add("message_id IN (" + string.Join(",", filter.MessageIds) + ")");
 			}
 
-			return conditions.Count == 0 ? "" : " WHERE " + string.Join(" AND ", conditions);
+			if (conditions.Count == 0) {
+				return "";
+			}
+
+			if (invert) {
+				return " WHERE NOT (" + string.Join(" AND ", conditions) + ")";
+			}
+			else {
+				return " WHERE " + string.Join(" AND ", conditions);
+			}
 		}
 	}
 }