Fix broken links to image embeds in viewer

Closes #256

app/.idea/.idea.DiscordHistoryTracker/.idea/codeStyles/Project.xml

@@ -13,10 +13,10 @@
     <CssCodeStyleSettings>
       <option name="HEX_COLOR_LOWER_CASE" value="true" />
     </CssCodeStyleSettings>
-    <DB2CodeStyleSettings version="6">
+    <DB2CodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </DB2CodeStyleSettings>
-    <DerbyCodeStyleSettings version="6">
+    <DerbyCodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </DerbyCodeStyleSettings>
     <GoCodeStyleSettings>
@@ -26,10 +26,10 @@
       <option name="WRAP_FUNC_PARAMS" value="5" />
       <option name="WRAP_FUNC_RESULT" value="5" />
     </GoCodeStyleSettings>
-    <H2CodeStyleSettings version="6">
+    <H2CodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </H2CodeStyleSettings>
-    <HSQLCodeStyleSettings version="6">
+    <HSQLCodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </HSQLCodeStyleSettings>
     <HTMLCodeStyleSettings>
@@ -85,10 +85,10 @@
     <LessCodeStyleSettings>
       <option name="HEX_COLOR_LOWER_CASE" value="true" />
     </LessCodeStyleSettings>
-    <MSSQLCodeStyleSettings version="6">
+    <MSSQLCodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </MSSQLCodeStyleSettings>
-    <MySQLCodeStyleSettings version="6">
+    <MySQLCodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </MySQLCodeStyleSettings>
     <Objective-C>
@@ -98,7 +98,7 @@
       <option name="SPACE_BEFORE_INIT_LIST" value="true" />
       <option name="SPACE_AFTER_DICTIONARY_LITERAL_COLON" value="false" />
     </Objective-C>
-    <OracleCodeStyleSettings version="6">
+    <OracleCodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </OracleCodeStyleSettings>
     <PHPCodeStyleSettings>
@@ -116,7 +116,7 @@
       <option name="NEW_LINE_AFTER_PHP_OPENING_TAG" value="true" />
       <option name="SPACE_AROUND_ASSIGNMENT_IN_DECLARE" value="true" />
     </PHPCodeStyleSettings>
-    <PostgresCodeStyleSettings version="6">
+    <PostgresCodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </PostgresCodeStyleSettings>
     <Properties>
@@ -143,13 +143,16 @@
       <option name="INDENT_WHEN_CASES" value="true" />
       <option name="CHAIN_CALLS_ALIGNMENT" value="2" />
     </Ruby>
-    <SQLiteCodeStyleSettings version="6">
+    <SQLiteCodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </SQLiteCodeStyleSettings>
     <ScssCodeStyleSettings>
       <option name="HEX_COLOR_LOWER_CASE" value="true" />
     </ScssCodeStyleSettings>
-    <SqlCodeStyleSettings version="6">
+    <Shell_Script>
+      <option name="KEEP_COLUMN_ALIGNMENT_PADDING" value="true" />
+    </Shell_Script>
+    <SqlCodeStyleSettings version="7">
       <option name="KEYWORD_CASE" value="2" />
       <option name="TYPE_CASE" value="2" />
       <option name="CUSTOM_TYPE_CASE" value="2" />
@@ -173,9 +176,10 @@
       <option name="CONSTRAINT_WRAP_3" value="true" />
       <option name="CONSTRAINT_WRAP_4" value="true" />
       <option name="VIEW_INDENT_QUERY" value="true" />
+      <option name="IMP_LOOP_LOOP_INDENT" value="false" />
       <option name="EXPR_CASE_WHEN_WRAP" value="false" />
     </SqlCodeStyleSettings>
-    <SybaseCodeStyleSettings version="6">
+    <SybaseCodeStyleSettings version="7">
       <option name="USE_GENERIC_STYLE" value="true" />
     </SybaseCodeStyleSettings>
     <TypeScriptCodeStyleSettings version="0">
@@ -203,6 +207,11 @@
         <option name="KEEP_INDENTS_ON_EMPTY_LINES" value="true" />
       </indentOptions>
     </codeStyleSettings>
+    <codeStyleSettings language="Gherkin">
+      <indentOptions>
+        <option name="KEEP_INDENTS_ON_EMPTY_LINES" value="true" />
+      </indentOptions>
+    </codeStyleSettings>
     <codeStyleSettings language="Groovy">
       <option name="ELSE_ON_NEW_LINE" value="true" />
       <option name="SPACE_WITHIN_ARRAY_INITIALIZER_BRACES" value="true" />
@@ -282,6 +291,13 @@
         <option name="KEEP_INDENTS_ON_EMPTY_LINES" value="true" />
       </indentOptions>
     </codeStyleSettings>
+    <codeStyleSettings language="Markdown">
+      <indentOptions>
+        <option name="INDENT_SIZE" value="2" />
+        <option name="CONTINUATION_INDENT_SIZE" value="2" />
+        <option name="TAB_SIZE" value="2" />
+      </indentOptions>
+    </codeStyleSettings>
     <codeStyleSettings language="ObjectiveC">
       <option name="LINE_COMMENT_AT_FIRST_COLUMN" value="false" />
       <option name="BLOCK_COMMENT_AT_FIRST_COLUMN" value="false" />
@@ -342,7 +358,6 @@
       </indentOptions>
     </codeStyleSettings>
     <codeStyleSettings language="Rust">
-      <option name="RIGHT_MARGIN" value="140" />
       <option name="ALIGN_MULTILINE_CHAINED_METHODS" value="true" />
       <indentOptions>
         <option name="USE_TAB_CHARACTER" value="true" />
@@ -357,6 +372,7 @@
     </codeStyleSettings>
     <codeStyleSettings language="SCSS">
       <indentOptions>
+        <option name="CONTINUATION_INDENT_SIZE" value="2" />
         <option name="KEEP_INDENTS_ON_EMPTY_LINES" value="true" />
       </indentOptions>
     </codeStyleSettings>
@@ -367,13 +383,6 @@
         <option name="KEEP_INDENTS_ON_EMPTY_LINES" value="true" />
       </indentOptions>
     </codeStyleSettings>
-    <codeStyleSettings language="Shell Script">
-      <indentOptions>
-        <option name="INDENT_SIZE" value="4" />
-        <option name="TAB_SIZE" value="4" />
-        <option name="USE_TAB_CHARACTER" value="true" />
-      </indentOptions>
-    </codeStyleSettings>
     <codeStyleSettings language="TOML">
       <indentOptions>
         <option name="CONTINUATION_INDENT_SIZE" value="4" />
@@ -427,6 +436,9 @@
     </codeStyleSettings>
     <codeStyleSettings language="liquid">
       <indentOptions>
+        <option name="INDENT_SIZE" value="2" />
+        <option name="CONTINUATION_INDENT_SIZE" value="2" />
+        <option name="TAB_SIZE" value="2" />
         <option name="KEEP_INDENTS_ON_EMPTY_LINES" value="true" />
       </indentOptions>
     </codeStyleSettings>

app/.idea/.idea.DiscordHistoryTracker/.idea/inspectionProfiles/Project.xml

@@ -91,7 +91,6 @@
     <inspection_tool class="ComparatorNotSerializable" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="CompareToUsesNonFinalVariable" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ComparisonOfShortAndChar" enabled="true" level="WARNING" enabled_by_default="true" />
-    <inspection_tool class="ComposeMissingKeys" enabled="true" level="ERROR" enabled_by_default="true" />
     <inspection_tool class="ConditionSignal" enabled="true" level="WARNING" enabled_by_default="true" />
     <inspection_tool class="ConditionalExpression" enabled="true" level="INFORMATION" enabled_by_default="true">
       <option name="ignoreSimpleAssignmentsAndReturns" value="true" />
@@ -362,7 +361,7 @@
     </inspection_tool>
     <inspection_tool class="LocalVariableDeclarationSideOnly" enabled="true" level="ERROR" enabled_by_default="true" />
     <inspection_tool class="LocalVariableNamingConventionJS" enabled="true" level="WARNING" enabled_by_default="true">
-      <option name="m_regex" value="[a-z][A-Za-z]*" />
+      <option name="m_regex" value="[a-z][A-Za-z0-9]*" />
       <option name="m_minLength" value="0" />
       <option name="m_maxLength" value="99" />
     </inspection_tool>

app/.idea/.idea.DiscordHistoryTracker/.idea/libraries/Generated_files.xml

@@ -1,22 +0,0 @@
-<component name="libraryTable">
-  <library name="Generated files" type="javaScript">
-    <properties>
-      <sourceFilesUrls>
-        <item url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/discord.js" />
-        <item url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/dom.js" />
-        <item url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/gui.js" />
-        <item url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/settings.js" />
-        <item url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/state.js" />
-      </sourceFilesUrls>
-    </properties>
-    <CLASSES>
-      <root url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/discord.js" />
-      <root url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/dom.js" />
-      <root url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/gui.js" />
-      <root url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/settings.js" />
-      <root url="file://$PROJECT_DIR$/Resources/Tracker/scripts.min/state.js" />
-    </CLASSES>
-    <JAVADOC />
-    <SOURCES />
-  </library>
-</component>

app/Desktop/Arguments.cs

@@ -15,6 +15,7 @@ sealed class Arguments {
 	public string? DatabaseFile { get; }
 	public ushort? ServerPort { get; }
 	public string? ServerToken { get; }
+	public byte? ConcurrentDownloads { get; }
 
 	public Arguments(IReadOnlyList<string> args) {
 		for (int i = FirstArgument; i < args.Count; i++) {
@@ -50,11 +51,11 @@ sealed class Arguments {
 					continue;
 
 				case "-port": {
-					if (ushort.TryParse(value, out var port)) {
+					if (!ushort.TryParse(value, out var port)) {
-						ServerPort = port;
+						Log.Warn("Invalid port number: " + value);
 					}
 					else {
-						Log.Warn("Invalid port number: " + value);
+						ServerPort = port;
 					}
 
 					continue;
@@ -64,6 +65,20 @@ sealed class Arguments {
 					ServerToken = value;
 					continue;
 				
+				case "-concurrentdownloads":
+					if (!ulong.TryParse(value, out var concurrentDownloads) || concurrentDownloads == 0) {
+						Log.Warn("Invalid concurrent downloads count: " + value);
+					}
+					else if (concurrentDownloads > 10) {
+						Log.Warn("Limiting concurrent downloads to 10");
+						ConcurrentDownloads = 10;
+					}
+					else {
+						ConcurrentDownloads = (byte) concurrentDownloads;
+					}
+					
+					continue;
+
 				default:
 					Log.Warn("Unknown command line argument: " + key);
 					break;

app/Desktop/Desktop.csproj

@@ -39,11 +39,6 @@
     <EmbeddedResource Include="Resources/tracker-loader.js">
       <LogicalName>tracker-loader.js</LogicalName>
     </EmbeddedResource>
-    <EmbeddedResource Include="../Resources/Viewer/**">
-      <LogicalName>Viewer\%(RecursiveDir)%(Filename)%(Extension)</LogicalName>
-      <Link>Resources/Viewer/%(RecursiveDir)%(Filename)%(Extension)</Link>
-      <Visible>false</Visible>
-    </EmbeddedResource>
   </ItemGroup>
   
 </Project>

app/Desktop/Main/MainWindow.axaml.cs

@@ -1,9 +1,7 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
-using System.IO;
 using System.Threading.Tasks;
 using Avalonia.Controls;
-using DHT.Desktop.Main.Pages;
 using DHT.Utils.Logging;
 using JetBrains.Annotations;
 
@@ -43,13 +41,5 @@ public sealed partial class MainWindow : Window {
 				Log.Error("Caught exception while disposing window: " + ex);
 			}
 		}
-
-		foreach (var temporaryFile in ViewerPageModel.TemporaryFiles) {
-			try {
-				File.Delete(temporaryFile);
-			} catch (Exception) {
-				// ignored
-			}
-		}
 	}
 }

app/Desktop/Main/MainWindowModel.cs

@@ -30,6 +30,7 @@ sealed partial class MainWindowModel : ObservableObject, IAsyncDisposable {
 	private MainContentScreenModel? mainContentScreenModel;
 
 	private readonly Window window;
+	private readonly int? concurrentDownloads;
 
 	private State? state;
 
@@ -73,6 +74,8 @@ sealed partial class MainWindowModel : ObservableObject, IAsyncDisposable {
 		if (args.ServerToken != null) {
 			ServerConfiguration.Token = args.ServerToken;
 		}
+		
+		concurrentDownloads = args.ConcurrentDownloads;
 	}
 
 	private async void OnDatabaseSelected(object? sender, IDatabaseFile db) {
@@ -80,7 +83,7 @@ sealed partial class MainWindowModel : ObservableObject, IAsyncDisposable {
 		
 		await DisposeState();
 		
-		state = new State(db);
+		state = new State(db, concurrentDownloads);
 
 		try {
 			await state.Server.Start(ServerConfiguration.Port, ServerConfiguration.Token);

app/Desktop/Main/Pages/DebugPageModel.cs

@@ -10,164 +10,164 @@ using DHT.Server;
 using DHT.Server.Data;
 using DHT.Server.Service;
 
-namespace DHT.Desktop.Main.Pages {
+namespace DHT.Desktop.Main.Pages;
-	sealed class DebugPageModel {
-		public string GenerateChannels { get; set; } = "0";
-		public string GenerateUsers { get; set; } = "0";
-		public string GenerateMessages { get; set; } = "0";
 
-		private readonly Window window;
+sealed class DebugPageModel {
-		private readonly State state;
+	public string GenerateChannels { get; set; } = "0";
+	public string GenerateUsers { get; set; } = "0";
+	public string GenerateMessages { get; set; } = "0";
 
-		[Obsolete("Designer")]
+	private readonly Window window;
-		public DebugPageModel() : this(null!, State.Dummy) {}
+	private readonly State state;
 
-		public DebugPageModel(Window window, State state) {
+	[Obsolete("Designer")]
-			this.window = window;
+	public DebugPageModel() : this(null!, State.Dummy) {}
-			this.state = state;
+
+	public DebugPageModel(Window window, State state) {
+		this.window = window;
+		this.state = state;
+	}
+
+	public async void OnClickAddRandomDataToDatabase() {
+		if (!int.TryParse(GenerateChannels, out int channels) || channels < 1) {
+			await Dialog.ShowOk(window, "Generate Random Data", "Amount of channels must be at least 1!");
+			return;
 		}
 
-		public async void OnClickAddRandomDataToDatabase() {
+		if (!int.TryParse(GenerateUsers, out int users) || users < 1) {
-			if (!int.TryParse(GenerateChannels, out int channels) || channels < 1) {
+			await Dialog.ShowOk(window, "Generate Random Data", "Amount of users must be at least 1!");
-				await Dialog.ShowOk(window, "Generate Random Data", "Amount of channels must be at least 1!");
+			return;
-				return;
-			}
-
-			if (!int.TryParse(GenerateUsers, out int users) || users < 1) {
-				await Dialog.ShowOk(window, "Generate Random Data", "Amount of users must be at least 1!");
-				return;
-			}
-
-			if (!int.TryParse(GenerateMessages, out int messages) || messages < 1) {
-				await Dialog.ShowOk(window, "Generate Random Data", "Amount of messages must be at least 1!");
-				return;
-			}
-
-			await ProgressDialog.Show(window, "Generating Random Data", async (_, callback) => await GenerateRandomData(channels, users, messages, callback));
 		}
 
-		private const int BatchSize = 500;
+		if (!int.TryParse(GenerateMessages, out int messages) || messages < 1) {
+			await Dialog.ShowOk(window, "Generate Random Data", "Amount of messages must be at least 1!");
+			return;
+		}
 
-		private async Task GenerateRandomData(int channelCount, int userCount, int messageCount, IProgressCallback callback) {
+		await ProgressDialog.Show(window, "Generating Random Data", async (_, callback) => await GenerateRandomData(channels, users, messages, callback));
-			int batchCount = (messageCount + BatchSize - 1) / BatchSize;
+	}
-			await callback.Update("Adding messages in batches of " + BatchSize, 0, batchCount);
 
-			var rand = new Random();
+	private const int BatchSize = 500;
-			var server = new DHT.Server.Data.Server {
-				Id = RandomId(rand),
-				Name = RandomName("s"),
-				Type = ServerType.Server,
-			};
 
-			var channels = Enumerable.Range(0, channelCount).Select(i => new Channel {
+	private async Task GenerateRandomData(int channelCount, int userCount, int messageCount, IProgressCallback callback) {
-				Id = RandomId(rand),
+		int batchCount = (messageCount + BatchSize - 1) / BatchSize;
-				Server = server.Id,
+		await callback.Update("Adding messages in batches of " + BatchSize, 0, batchCount);
-				Name = RandomName("c"),
+
-				ParentId = null,
+		var rand = new Random();
-				Position = i,
+		var server = new DHT.Server.Data.Server {
-				Topic = RandomText(rand, 10),
+			Id = RandomId(rand),
-				Nsfw = rand.Next(4) == 0,
+			Name = RandomName("s"),
+			Type = ServerType.Server,
+		};
+
+		var channels = Enumerable.Range(0, channelCount).Select(i => new Channel {
+			Id = RandomId(rand),
+			Server = server.Id,
+			Name = RandomName("c"),
+			ParentId = null,
+			Position = i,
+			Topic = RandomText(rand, 10),
+			Nsfw = rand.Next(4) == 0,
+		}).ToArray();
+
+		var users = Enumerable.Range(0, userCount).Select(_ => new User {
+			Id = RandomId(rand),
+			Name = RandomName("u"),
+			AvatarUrl = null,
+			Discriminator = rand.Next(0, 9999).ToString(),
+		}).ToArray();
+
+		await state.Db.Users.Add(users);
+		await state.Db.Servers.Add([server]);
+		await state.Db.Channels.Add(channels);
+
+		var now = DateTimeOffset.Now;
+		int batchIndex = 0;
+
+		while (messageCount > 0) {
+			int hourOffset = batchIndex;
+
+			var messages = Enumerable.Range(0, Math.Min(messageCount, BatchSize)).Select(i => {
+				DateTimeOffset time = now.AddHours(hourOffset).AddMinutes(i * 60.0 / BatchSize);
+				DateTimeOffset? edit = rand.Next(100) == 0 ? time.AddSeconds(rand.Next(1, 60)) : null;
+
+				var timeMillis = time.ToUnixTimeMilliseconds();
+				var editMillis = edit?.ToUnixTimeMilliseconds();
+
+				return new Message {
+					Id = (ulong) timeMillis,
+					Sender = RandomBiasedIndex(rand, users).Id,
+					Channel = RandomBiasedIndex(rand, channels).Id,
+					Text = RandomText(rand, 100),
+					Timestamp = timeMillis,
+					EditTimestamp = editMillis,
+					RepliedToId = null,
+					Attachments = ImmutableList<Attachment>.Empty,
+					Embeds = ImmutableList<Embed>.Empty,
+					Reactions = ImmutableList<Reaction>.Empty,
+				};
 			}).ToArray();
 
-			var users = Enumerable.Range(0, userCount).Select(_ => new User {
+			await state.Db.Messages.Add(messages);
-				Id = RandomId(rand),
-				Name = RandomName("u"),
-				AvatarUrl = null,
-				Discriminator = rand.Next(0, 9999).ToString(),
-			}).ToArray();
 
-			await state.Db.Users.Add(users);
+			messageCount -= BatchSize;
-			await state.Db.Servers.Add([server]);
+			await callback.Update("Adding messages in batches of " + BatchSize, ++batchIndex, batchCount);
-			await state.Db.Channels.Add(channels);
-
-			var now = DateTimeOffset.Now;
-			int batchIndex = 0;
-
-			while (messageCount > 0) {
-				int hourOffset = batchIndex;
-
-				var messages = Enumerable.Range(0, Math.Min(messageCount, BatchSize)).Select(i => {
-					DateTimeOffset time = now.AddHours(hourOffset).AddMinutes(i * 60.0 / BatchSize);
-					DateTimeOffset? edit = rand.Next(100) == 0 ? time.AddSeconds(rand.Next(1, 60)) : null;
-
-					var timeMillis = time.ToUnixTimeMilliseconds();
-					var editMillis = edit?.ToUnixTimeMilliseconds();
-
-					return new Message {
-						Id = (ulong) timeMillis,
-						Sender = RandomBiasedIndex(rand, users).Id,
-						Channel = RandomBiasedIndex(rand, channels).Id,
-						Text = RandomText(rand, 100),
-						Timestamp = timeMillis,
-						EditTimestamp = editMillis,
-						RepliedToId = null,
-						Attachments = ImmutableList<Attachment>.Empty,
-						Embeds = ImmutableList<Embed>.Empty,
-						Reactions = ImmutableList<Reaction>.Empty,
-					};
-				}).ToArray();
-
-				await state.Db.Messages.Add(messages);
-
-				messageCount -= BatchSize;
-				await callback.Update("Adding messages in batches of " + BatchSize, ++batchIndex, batchCount);
-			}
 		}
+	}
 
-		private static ulong RandomId(Random rand) {
+	private static ulong RandomId(Random rand) {
-			ulong h = unchecked((ulong) rand.Next());
+		ulong h = unchecked((ulong) rand.Next());
-			ulong l = unchecked((ulong) rand.Next());
+		ulong l = unchecked((ulong) rand.Next());
-			return (h << 32) | l;
+		return (h << 32) | l;
-		}
+	}
 
-		private static string RandomName(string prefix) {
+	private static string RandomName(string prefix) {
-			return prefix + "-" + ServerUtils.GenerateRandomToken(5);
+		return prefix + "-" + ServerUtils.GenerateRandomToken(5);
-		}
+	}
 
-		private static T RandomBiasedIndex<T>(Random rand, T[] options) {
+	private static T RandomBiasedIndex<T>(Random rand, T[] options) {
-			return options[(int) Math.Floor(options.Length * rand.NextDouble() * rand.NextDouble())];
+		return options[(int) Math.Floor(options.Length * rand.NextDouble() * rand.NextDouble())];
-		}
+	}
 
-		private static readonly string[] RandomWords = [
+	private static readonly string[] RandomWords = [
-			"apple", "apricot", "artichoke", "arugula", "asparagus", "avocado",
+		"apple", "apricot", "artichoke", "arugula", "asparagus", "avocado",
-			"banana", "bean", "beechnut", "beet", "blackberry", "blackcurrant", "blueberry", "boysenberry", "bramble", "broccoli",
+		"banana", "bean", "beechnut", "beet", "blackberry", "blackcurrant", "blueberry", "boysenberry", "bramble", "broccoli",
-			"cabbage", "cacao", "cantaloupe", "caper", "carambola", "carrot", "cauliflower", "celery", "chard", "cherry", "chokeberry", "citron", "clementine", "coconut", "corn", "crabapple", "cranberry", "cucumber", "currant",
+		"cabbage", "cacao", "cantaloupe", "caper", "carambola", "carrot", "cauliflower", "celery", "chard", "cherry", "chokeberry", "citron", "clementine", "coconut", "corn", "crabapple", "cranberry", "cucumber", "currant",
-			"daikon", "date", "dewberry", "durian",
+		"daikon", "date", "dewberry", "durian",
-			"edamame", "eggplant", "elderberry", "endive",
+		"edamame", "eggplant", "elderberry", "endive",
-			"fig",
+		"fig",
-			"garlic", "ginger", "gooseberry", "grape", "grapefruit", "guava",
+		"garlic", "ginger", "gooseberry", "grape", "grapefruit", "guava",
-			"honeysuckle", "horseradish", "huckleberry",
+		"honeysuckle", "horseradish", "huckleberry",
-			"jackfruit", "jicama",
+		"jackfruit", "jicama",
-			"kale", "kiwi", "kohlrabi", "kumquat",
+		"kale", "kiwi", "kohlrabi", "kumquat",
-			"leek", "lemon", "lentil", "lettuce", "lime",
+		"leek", "lemon", "lentil", "lettuce", "lime",
-			"mandarin", "mango", "mushroom", "myrtle",
+		"mandarin", "mango", "mushroom", "myrtle",
-			"nectarine", "nut",
+		"nectarine", "nut",
-			"olive", "okra", "onion", "orange",
+		"olive", "okra", "onion", "orange",
-			"papaya", "parsnip", "pawpaw", "peach", "pear", "pea", "pepper", "persimmon", "pineapple", "plum", "plantain", "pomegranate", "pomelo", "potato", "prune", "pumpkin",
+		"papaya", "parsnip", "pawpaw", "peach", "pear", "pea", "pepper", "persimmon", "pineapple", "plum", "plantain", "pomegranate", "pomelo", "potato", "prune", "pumpkin",
-			"quandong", "quinoa",
+		"quandong", "quinoa",
-			"radicchio", "radish", "raisin", "raspberry", "redcurrant", "rhubarb", "rutabaga",
+		"radicchio", "radish", "raisin", "raspberry", "redcurrant", "rhubarb", "rutabaga",
-			"spinach", "strawberry", "squash",
+		"spinach", "strawberry", "squash",
-			"tamarind", "tangerine", "tomatillo", "tomato", "turnip",
+		"tamarind", "tangerine", "tomatillo", "tomato", "turnip",
-			"vanilla",
+		"vanilla",
-			"watercress", "watermelon",
+		"watercress", "watermelon",
-			"yam",
+		"yam",
-			"zucchini"
+		"zucchini"
-		];
+	];
 
-		private static string RandomText(Random rand, int maxWords) {
+	private static string RandomText(Random rand, int maxWords) {
-			int wordCount = 1 + (int) Math.Floor(maxWords * Math.Pow(rand.NextDouble(), 3));
+		int wordCount = 1 + (int) Math.Floor(maxWords * Math.Pow(rand.NextDouble(), 3));
-			return string.Join(' ', Enumerable.Range(0, wordCount).Select(_ => RandomWords[rand.Next(RandomWords.Length)]));
+		return string.Join(' ', Enumerable.Range(0, wordCount).Select(_ => RandomWords[rand.Next(RandomWords.Length)]));
-		}
 	}
 }
 #else
-namespace DHT.Desktop.Main.Pages {
+namespace DHT.Desktop.Main.Pages;
-	sealed class DebugPageModel {
-		public string GenerateChannels { get; set; } = "0";
-		public string GenerateUsers { get; set; } = "0";
-		public string GenerateMessages { get; set; } = "0";
 
-		public void OnClickAddRandomDataToDatabase() {}
+sealed class DebugPageModel {
-	}
+	public string GenerateChannels { get; set; } = "0";
+	public string GenerateUsers { get; set; } = "0";
+	public string GenerateMessages { get; set; } = "0";
+
+	public void OnClickAddRandomDataToDatabase() {}
 }
 #endif

app/Desktop/Main/Pages/ViewerPage.axaml

@@ -21,7 +21,6 @@
     <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>
         <controls:MessageFilterPanel DataContext="{Binding FilterModel}" />
         <Expander Header="Database Tools">

app/Desktop/Main/Pages/ViewerPageModel.cs

@@ -1,34 +1,22 @@
 using System;
-using System.Collections.Concurrent;
 using System.ComponentModel;
 using System.Diagnostics;
-using System.IO;
-using System.Text;
 using System.Threading.Tasks;
 using System.Web;
 using Avalonia.Controls;
-using Avalonia.Platform.Storage;
 using CommunityToolkit.Mvvm.ComponentModel;
 using DHT.Desktop.Common;
-using DHT.Desktop.Dialogs.File;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Dialogs.Progress;
 using DHT.Desktop.Main.Controls;
 using DHT.Desktop.Server;
 using DHT.Server;
 using DHT.Server.Data.Filters;
-using DHT.Server.Database.Export;
+using DHT.Server.Service.Viewer;
-using static DHT.Desktop.Program;
 
 namespace DHT.Desktop.Main.Pages;
 
 sealed partial class ViewerPageModel : ObservableObject, IDisposable {
-	public static readonly ConcurrentBag<string> TemporaryFiles = [];
-
-	private static readonly FilePickerFileType[] ViewerFileTypes = [
-		FileDialogs.CreateFilter("Discord History Viewer", ["html"])
-	];
-
 	public bool DatabaseToolFilterModeKeep { get; set; } = true;
 	public bool DatabaseToolFilterModeRemove { get; set; } = false;
 
@@ -61,101 +49,18 @@ sealed partial class ViewerPageModel : ObservableObject, IDisposable {
 
 	public async void OnClickOpenViewer() {
 		try {
-			var fullPath = await PrepareTemporaryViewerFile();
+			string serverUrl = "http://127.0.0.1:" + ServerConfiguration.Port;
+			string serverToken = ServerConfiguration.Token;
+			string sessionId = state.ViewerSessions.Register(new ViewerSession(FilterModel.CreateFilter())).ToString();
 			
-			string jsConstants = $"""
+			Process.Start(new ProcessStartInfo(serverUrl + "/viewer/?token=" + HttpUtility.UrlEncode(serverToken) + "&session=" + HttpUtility.UrlEncode(sessionId)) {
-			                      window.DHT_SERVER_URL = "{HttpUtility.JavaScriptStringEncode("http://127.0.0.1:" + ServerConfiguration.Port)}";
-			                      window.DHT_SERVER_TOKEN = "{HttpUtility.JavaScriptStringEncode(ServerConfiguration.Token)}";
-			                      """;
-
-			await ProgressDialog.ShowIndeterminate(window, "Open Viewer", "Creating viewer...", _ => Task.Run(() => WriteViewerFile(fullPath, jsConstants)));
-			
-			Process.Start(new ProcessStartInfo(fullPath) {
 				UseShellExecute = true
 			});
 		} catch (Exception e) {
-			await Dialog.ShowOk(window, "Open Viewer", "Could not create or save viewer: " + e.Message);
+			await Dialog.ShowOk(window, "Open Viewer", "Could not open viewer: " + e.Message);
 		}
 	}
 
-	private async Task<string> PrepareTemporaryViewerFile() {
-		return await Task.Run(() => {
-			string rootPath = Path.Combine(Path.GetTempPath(), "DiscordHistoryTracker");
-			string filenameBase = Path.GetFileNameWithoutExtension(state.Db.Path) + "-" + DateTime.Now.ToString("yyyy-MM-dd");
-			string fullPath = Path.Combine(rootPath, filenameBase + ".html");
-			
-			int counter = 0;
-
-			while (File.Exists(fullPath)) {
-				++counter;
-				fullPath = Path.Combine(rootPath, filenameBase + "-" + counter + ".html");
-			}
-
-			TemporaryFiles.Add(fullPath);
-
-			Directory.CreateDirectory(rootPath);
-
-			return fullPath;
-		});
-	}
-
-	public async void OnClickSaveViewer() {
-		string? path = await window.StorageProvider.SaveFile(new FilePickerSaveOptions {
-			Title = "Save Viewer",
-			FileTypeChoices = ViewerFileTypes,
-			SuggestedFileName = Path.GetFileNameWithoutExtension(state.Db.Path) + ".html",
-			SuggestedStartLocation = await FileDialogs.GetSuggestedStartLocation(window, Path.GetDirectoryName(state.Db.Path)),
-		});
-
-		if (path == null) {
-			return;
-		}
-
-		try {
-			await ProgressDialog.ShowIndeterminate(window, "Save Viewer", "Creating viewer...", _ => Task.Run(() => WriteViewerFile(path, string.Empty)));
-		} catch (Exception e) {
-			await Dialog.ShowOk(window, "Save Viewer", "Could not create or save viewer: " + e.Message);
-		}
-	}
-
-	private async Task WriteViewerFile(string path, string jsConstants) {
-		const string ArchiveTag = "/*[ARCHIVE]*/";
-
-		string indexFile = await Resources.ReadTextAsync("Viewer/index.html");
-		string viewerTemplate = indexFile.Replace("/*[CONSTANTS]*/", jsConstants)
-		                                 .Replace("/*[JS]*/", await Resources.ReadJoinedAsync("Viewer/scripts/", '\n'))
-		                                 .Replace("/*[CSS]*/", await Resources.ReadJoinedAsync("Viewer/styles/", '\n'));
-
-		int viewerArchiveTagStart = viewerTemplate.IndexOf(ArchiveTag);
-		int viewerArchiveTagEnd = viewerArchiveTagStart + ArchiveTag.Length;
-
-		string jsonTempFile = path + ".tmp";
-
-		await using (var jsonStream = new FileStream(jsonTempFile, FileMode.Create, FileAccess.ReadWrite, FileShare.Read)) {
-			await ViewerJsonExport.Generate(jsonStream, state.Db, FilterModel.CreateFilter());
-
-			char[] jsonBuffer = new char[Math.Min(32768, jsonStream.Position)];
-			jsonStream.Position = 0;
-
-			await using (var outputStream = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.Read))
-			await using (var outputWriter = new StreamWriter(outputStream, Encoding.UTF8)) {
-				await outputWriter.WriteAsync(viewerTemplate[..viewerArchiveTagStart]);
-
-				using (var jsonReader = new StreamReader(jsonStream, Encoding.UTF8)) {
-					int readBytes;
-					while ((readBytes = await jsonReader.ReadAsync(jsonBuffer, 0, jsonBuffer.Length)) > 0) {
-						string jsonChunk = new string(jsonBuffer, 0, readBytes);
-						await outputWriter.WriteAsync(HttpUtility.JavaScriptStringEncode(jsonChunk));
-					}
-				}
-
-				await outputWriter.WriteAsync(viewerTemplate[viewerArchiveTagEnd..]);
-			}
-		}
-
-		File.Delete(jsonTempFile);
-	}
-
 	public async Task OnClickApplyFiltersToDatabase() {
 		var filter = FilterModel.CreateFilter();
 		var messageCount = await ProgressDialog.ShowIndeterminate(window, "Apply Filters", "Counting matching messages...", _ => state.Db.Messages.Count(filter));

app/Resources/Viewer/index.html

@@ -2,16 +2,24 @@
 <html lang="en">
   <head>
     <meta charset="utf-8">
+    <meta name="referrer" content="no-referrer">
+    
     <title>Discord Offline History</title>
     
+    <link rel="icon" href="favicon.ico">
+    
+    <link rel="stylesheet" href="styles/main.css">
+    <link rel="stylesheet" href="styles/menu.css">
+    <link rel="stylesheet" href="styles/channels.css">
+    <link rel="stylesheet" href="styles/messages.css">
+    <link rel="stylesheet" href="styles/modal.css">
+    
     <script type="text/javascript">
-		window.DHT_EMBEDDED = "/*[ARCHIVE]*/";
+		const query = new URLSearchParams(location.search);
-		/*[CONSTANTS]*/
+		window.DHT_SERVER_TOKEN = query.get("token");
-		/*[JS]*/
+		window.DHT_SERVER_SESSION = query.get("session");
     </script>
-    <style>
+    <script type="module" src="scripts/bootstrap.mjs"></script>
-      /*[CSS]*/
-    </style>
   </head>
   <body>
     <div id="menu">
@@ -65,7 +73,9 @@
     </div>
     
     <div id="app">
-      <div id="channels"></div>
+      <div id="channels">
+        <div class="loading"></div>
+      </div>
       <div id="messages"></div>
     </div>
     

app/Resources/Viewer/scripts/bootstrap.js

@@ -1,39 +0,0 @@
-document.addEventListener("DOMContentLoaded", () => {
-	DISCORD.setup();
-	GUI.setup();
-	
-	GUI.onOptionMessagesPerPageChanged(() => {
-		STATE.setMessagesPerPage(GUI.getOptionMessagesPerPage());
-	});
-	
-	STATE.setMessagesPerPage(GUI.getOptionMessagesPerPage());
-	
-	GUI.onOptMessageFilterChanged(filter => {
-		STATE.setActiveFilter(filter);
-	});
-	
-	GUI.onNavigationButtonClicked(action => {
-		STATE.updateCurrentPage(action);
-	});
-	
-	STATE.onUsersRefreshed(users => {
-		GUI.updateUserList(users);
-	});
-	
-	STATE.onChannelsRefreshed((channels, selected) => {
-		GUI.updateChannelList(channels, selected, STATE.selectChannel);
-	});
-	
-	STATE.onMessagesRefreshed(messages => {
-		GUI.updateNavigation(STATE.getCurrentPage(), STATE.getPageCount());
-		GUI.updateMessageList(messages);
-		GUI.scrollMessagesToTop();
-	});
-	
-	try {
-		STATE.uploadFile(JSON.parse(window.DHT_EMBEDDED));
-	} catch (e) {
-		console.error(e);
-		alert("Could not parse embedded file, see console for details.");
-	}
-});

app/Resources/Viewer/scripts/bootstrap.mjs

@@ -0,0 +1,110 @@
+import discord from "./discord.mjs";
+import gui from "./gui.mjs";
+import state from "./state.mjs";
+
+window.DISCORD = discord;
+
+document.addEventListener("DOMContentLoaded", () => {
+	discord.setup();
+	gui.setup();
+	
+	gui.onOptionMessagesPerPageChanged(() => {
+		state.setMessagesPerPage(gui.getOptionMessagesPerPage());
+	});
+	
+	state.setMessagesPerPage(gui.getOptionMessagesPerPage());
+	
+	gui.onOptMessageFilterChanged(filter => {
+		state.setActiveFilter(filter);
+	});
+	
+	gui.onNavigationButtonClicked(action => {
+		state.updateCurrentPage(action);
+	});
+	
+	state.onUsersRefreshed(users => {
+		gui.updateUserList(users);
+	});
+	
+	state.onChannelsRefreshed((channels, selected) => {
+		gui.updateChannelList(channels, selected, state.selectChannel);
+	});
+	
+	state.onMessagesRefreshed(messages => {
+		gui.updateNavigation(state.getCurrentPage(), state.getPageCount());
+		gui.updateMessageList(messages);
+		gui.scrollMessagesToTop();
+	});
+	
+	async function fetchUrl(path, contentType) {
+		const response = await fetch("/" + path + "?token=" + encodeURIComponent(window.DHT_SERVER_TOKEN) + "&session=" + encodeURIComponent(window.DHT_SERVER_SESSION), {
+			method: "GET",
+			headers: {
+				"Content-Type": contentType,
+			},
+			credentials: "omit",
+			redirect: "error",
+		});
+		
+		if (!response.ok) {
+			throw "Unexpected response status: " + response.statusText;
+		}
+		
+		return response;
+	}
+	
+	async function processLines(response, callback) {
+		let body = "";
+		
+		for await (const chunk of response.body.pipeThrough(new TextDecoderStream("utf-8"))) {
+			body += chunk;
+			
+			let startIndex = 0;
+			
+			while (true) {
+				const endIndex = body.indexOf("\n", startIndex);
+				if (endIndex === -1) {
+					break;
+				}
+				
+				callback(body.substring(startIndex, endIndex));
+				startIndex = endIndex + 1;
+			}
+			
+			body = body.substring(startIndex);
+		}
+		
+		if (body !== "") {
+			callback(body);
+		}
+	}
+	
+	async function loadData() {
+		try {
+			const metadataResponse = await fetchUrl("get-viewer-metadata", "application/json");
+			const metadataJson = await metadataResponse.json();
+			
+			const messagesResponse = await fetchUrl("get-viewer-messages", "application/x-ndjson");
+			const messages = {};
+			
+			await processLines(messagesResponse, line => {
+				const message = JSON.parse(line);
+				const channel = message.c;
+				
+				const channelMessages = messages[channel] || (messages[channel] = {});
+				channelMessages[message.id] = message;
+				
+				delete message.id;
+				delete message.c;
+			});
+			
+			state.uploadFile(metadataJson, messages);
+		} catch (e) {
+			console.error(e);
+			alert("Could not load data, see console for details.");
+			document.querySelector("#channels > div.loading").remove();
+		}
+	}
+	
+	loadData();
+});

app/Resources/Viewer/scripts/discord.mjs

@@ -1,4 +1,10 @@
-const DISCORD = (function() {
+import discord from "./discord.mjs";
+import dom from "./dom.mjs";
+import template from "./template.mjs";
+import settings from "./settings.mjs";
+import state from "./state.mjs";
+
+export default (function() {
 	const regex = {
 		formatBold: /\*\*([\s\S]+?)\*\*(?!\*)/g,
 		formatItalic1: /\*([\s\S]+?)\*(?!\*)/g,
@@ -35,17 +41,14 @@ const DISCORD = (function() {
 	let templateReaction;
 	let templateReactionCustom;
 	
-	const fileUrlProcessor = function(serverUrl, serverToken) {
+	const fileUrlProcessor = function(serverToken) {
-		if (typeof serverUrl === "string" && typeof serverToken === "string") {
+		if (typeof serverToken === "string") {
-			return url => serverUrl + "/get-downloaded-file/" + encodeURIComponent(url) + "?token=" + encodeURIComponent(serverToken);
+			return url => "/get-downloaded-file/" + encodeURIComponent(url) + "?token=" + encodeURIComponent(serverToken);
 		}
 		else {
 			return url => url;
 		}
-	}(
+	}(window.DHT_SERVER_TOKEN);
-		window["DHT_SERVER_URL"],
-		window["DHT_SERVER_TOKEN"]
-	);
 	
 	const getEmoji = function(name, id, extension) {
 		const tag = ":" + name + ":";
@@ -53,9 +56,9 @@ const DISCORD = (function() {
 	};
 	
 	const processMessageContents = function(contents) {
-		let processed = DOM.escapeHTML(contents.replace(regex.formatUrlNoEmbed, "$1"));
+		let processed = dom.escapeHTML(contents.replace(regex.formatUrlNoEmbed, "$1"));
 		
-		if (SETTINGS.enableFormatting) {
+		if (settings.enableFormatting) {
 			const escapeHtmlMatch = (full, match) => "&#" + match.charCodeAt(0) + ";";
 			
 			processed = processed
@@ -71,13 +74,13 @@ const DISCORD = (function() {
 				.replace(regex.formatStrike, "<s>$1</s>");
 		}
 		
-		const animatedEmojiExtension = SETTINGS.enableAnimatedEmoji ? "gif" : "webp";
+		const animatedEmojiExtension = settings.enableAnimatedEmoji ? "gif" : "webp";
 		
 		// noinspection HtmlUnknownTarget
 		processed = processed
 			.replace(regex.formatUrl, "<a href='$1' target='_blank' rel='noreferrer'>$1</a>")
-			.replace(regex.mentionChannel, (full, match) => "<span class='link mention-chat'>#" + STATE.getChannelName(match) + "</span>")
+			.replace(regex.mentionChannel, (full, match) => "<span class='link mention-chat'>#" + state.getChannelName(match) + "</span>")
-			.replace(regex.mentionUser, (full, match) => "<span class='link mention-user' title='#" + (STATE.getUserTag(match) || "????") + "'>@" + STATE.getUserName(match) + "</span>")
+			.replace(regex.mentionUser, (full, match) => "<span class='link mention-user' title='#" + (state.getUserTag(match) || "????") + "'>@" + state.getUserName(match) + "</span>")
 			.replace(regex.customEmojiStatic, (full, m1, m2) => getEmoji(m1, m2, "webp"))
 			.replace(regex.customEmojiAnimated, (full, m1, m2) => getEmoji(m1, m2, animatedEmojiExtension));
 		
@@ -89,7 +92,7 @@ const DISCORD = (function() {
 	};
 	
 	const getImageEmbed = function(url, image) {
-		if (!SETTINGS.enableImagePreviews) {
+		if (!settings.enableImagePreviews) {
 			return "";
 		}
 		
@@ -109,21 +112,21 @@ const DISCORD = (function() {
 	
 	return {
 		setup() {
-			templateChannelServer = new TEMPLATE([
+			templateChannelServer = new template([
-				"<div data-channel='{id}'>",
+				"<div class='channel' data-channel='{id}'>",
 				"<div class='info' title='{topic}'><strong class='name'>#{name}</strong>{nsfw}<span class='tag'>{msgcount}</span></div>",
 				"<span class='server'>{server.name} ({server.type})</span>",
 				"</div>"
 			].join(""));
 			
-			templateChannelPrivate = new TEMPLATE([
+			templateChannelPrivate = new template([
-				"<div data-channel='{id}'>",
+				"<div class='channel' data-channel='{id}'>",
 				"<div class='info'><strong class='name'>{name}</strong><span class='tag'>{msgcount}</span></div>",
 				"<span class='server'>({server.type})</span>",
 				"</div>"
 			].join(""));
 			
-			templateMessageNoAvatar = new TEMPLATE([
+			templateMessageNoAvatar = new template([
 				"<div>",
 				"<div class='reply-message'>{reply}</div>",
 				"<h2><strong class='username' title='#{user.tag}'>{user.name}</strong><span class='info time'>{timestamp}</span>{edit}{jump}</h2>",
@@ -132,7 +135,7 @@ const DISCORD = (function() {
 				"</div>"
 			].join(""));
 			
-			templateMessageWithAvatar = new TEMPLATE([
+			templateMessageWithAvatar = new template([
 				"<div>",
 				"<div class='reply-message reply-message-with-avatar'>{reply}</div>",
 				"<div class='avatar-wrapper'>",
@@ -147,50 +150,50 @@ const DISCORD = (function() {
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
-			templateUserAvatar = new TEMPLATE([
+			templateUserAvatar = new template([
 				"<img src='{url}' alt=''>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
-			templateAttachmentDownload = new TEMPLATE([
+			templateAttachmentDownload = new template([
 				"<a href='{url}' class='embed download'>Download {name}</a>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
-			templateEmbedImage = new TEMPLATE([
+			templateEmbedImage = new template([
-				"<a href='{url}' class='embed thumbnail loading'><img src='{src}' alt='' onload='DISCORD.handleImageLoad(this)' onerror='DISCORD.handleImageLoadError(this)'></a><br>"
+				"<a href='{url}' class='embed thumbnail loading'><img src='{src}' alt='' onload='window.DISCORD.handleImageLoad(this)' onerror='window.DISCORD.handleImageLoadError(this)'></a><br>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
-			templateEmbedImageWithSize = new TEMPLATE([
+			templateEmbedImageWithSize = new template([
-				"<a href='{url}' class='embed thumbnail loading'><img src='{src}' width='{width}' height='{height}' alt='' onload='DISCORD.handleImageLoad(this)' onerror='DISCORD.handleImageLoadError(this)'></a><br>"
+				"<a href='{url}' class='embed thumbnail loading'><img src='{src}' width='{width}' height='{height}' alt='' onload='window.DISCORD.handleImageLoad(this)' onerror='window.DISCORD.handleImageLoadError(this)'></a><br>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
-			templateEmbedRich = new TEMPLATE([
+			templateEmbedRich = new template([
 				"<div class='embed download'><a href='{url}' class='title'>{title}</a><p class='desc'>{description}</p></div>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
-			templateEmbedRichNoDescription = new TEMPLATE([
+			templateEmbedRichNoDescription = new template([
 				"<div class='embed download'><a href='{url}' class='title'>{title}</a></div>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
-			templateEmbedUrl = new TEMPLATE([
+			templateEmbedUrl = new template([
 				"<a href='{url}' class='embed download'>{url}</a>"
 			].join(""));
 			
-			templateEmbedUnsupported = new TEMPLATE([
+			templateEmbedUnsupported = new template([
 				"<div class='embed download'><p>(Unsupported embed)</p></div>"
 			].join(""));
 			
-			templateReaction = new TEMPLATE([
+			templateReaction = new template([
 				"<span class='reaction-wrapper'><span class='reaction-emoji'>{n}</span><span class='count'>{c}</span></span>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
-			templateReactionCustom = new TEMPLATE([
+			templateReactionCustom = new template([
 				"<span class='reaction-wrapper'><img src='{url}' alt=':{n}:' title=':{n}:' class='reaction-emoji-custom'><span class='count'>{c}</span></span>"
 			].join(""));
 		},
@@ -207,7 +210,7 @@ const DISCORD = (function() {
 		},
 		
 		isImageAttachment(attachment) {
-			const url = DOM.tryParseUrl(attachment.url);
+			const url = dom.tryParseUrl(attachment.url);
 			return url != null && isImageUrl(url);
 		},
 		
@@ -220,7 +223,7 @@ const DISCORD = (function() {
 		},
 		
 		getMessageHTML(message) { // noinspection FunctionWithInconsistentReturnsJS
-			return (SETTINGS.enableUserAvatars ? templateMessageWithAvatar : templateMessageNoAvatar).apply(message, (property, value) => {
+			return (settings.enableUserAvatars ? templateMessageWithAvatar : templateMessageNoAvatar).apply(message, (property, value) => {
 				if (property === "avatar") {
 					return value ? templateUserAvatar.apply(getAvatarUrlObject(value)) : "";
 				}
@@ -228,7 +231,7 @@ const DISCORD = (function() {
 					return value ? value : "????";
 				}
 				else if (property === "timestamp") {
-					return DOM.getHumanReadableTime(value);
+					return dom.getHumanReadableTime(value);
 				}
 				else if (property === "contents") {
 					return value && value.length > 0 ? processMessageContents(value) : "";
@@ -243,10 +246,10 @@ const DISCORD = (function() {
 							return templateEmbedUnsupported.apply(embed);
 						}
 						else if ("image" in embed && embed.image.url) {
-							return getImageEmbed(fileUrlProcessor(embed.url), embed.image);
+							return getImageEmbed(embed.url, embed.image);
 						}
 						else if ("thumbnail" in embed && embed.thumbnail.url) {
-							return getImageEmbed(fileUrlProcessor(embed.url), embed.thumbnail);
+							return getImageEmbed(embed.url, embed.thumbnail);
 						}
 						else if ("title" in embed && "description" in embed) {
 							return templateEmbedRich.apply(embed);
@@ -267,7 +270,7 @@ const DISCORD = (function() {
 					return value.map(attachment => {
 						const url = fileUrlProcessor(attachment.url);
 						
-						if (!DISCORD.isImageAttachment(attachment) || !SETTINGS.enableImagePreviews) {
+						if (!discord.isImageAttachment(attachment) || !settings.enableImagePreviews) {
 							return templateAttachmentDownload.apply({ url, name: attachment.name });
 						}
 						else if ("width" in attachment && "height" in attachment) {
@@ -279,10 +282,10 @@ const DISCORD = (function() {
 					}).join("");
 				}
 				else if (property === "edit") {
-					return value ? "<span class='info edited'>Edited " + DOM.getHumanReadableTime(value) + "</span>" : "";
+					return value ? "<span class='info edited'>Edited " + dom.getHumanReadableTime(value) + "</span>" : "";
 				}
 				else if (property === "jump") {
-					return STATE.hasActiveFilter ? "<span class='info jump' data-jump='" + value + "'>Jump to message</span>" : "";
+					return state.hasActiveFilter ? "<span class='info jump' data-jump='" + value + "'>Jump to message</span>" : "";
 				}
 				else if (property === "reply") {
 					if (!value) {
@@ -290,7 +293,7 @@ const DISCORD = (function() {
 					}
 					
 					const user = "<span class='reply-username' title='#" + (value.user.tag ? value.user.tag : "????") + "'>" + value.user.name + "</span>";
-					const avatar = SETTINGS.enableUserAvatars && value.avatar ? "<span class='reply-avatar'>" + templateUserAvatar.apply(getAvatarUrlObject(value.avatar)) + "</span>" : "";
+					const avatar = settings.enableUserAvatars && value.avatar ? "<span class='reply-avatar'>" + templateUserAvatar.apply(getAvatarUrlObject(value.avatar)) + "</span>" : "";
 					const contents = value.contents ? "<span class='reply-contents'>" + processMessageContents(value.contents) + "</span>" : "";
 					
 					return "<span class='jump' data-jump='" + value.id + "'>Jump to reply</span><span class='user'>" + avatar + user + "</span>" + contents;
@@ -302,7 +305,7 @@ const DISCORD = (function() {
 					
 					return "<div class='reactions'>" + value.map(reaction => {
 						if ("id" in reaction){
-							const ext = reaction.a && SETTINGS.enableAnimatedEmoji ? "gif" : "webp";
+							const ext = reaction.a && settings.enableAnimatedEmoji ? "gif" : "webp";
 							const url = fileUrlProcessor("https://cdn.discordapp.com/emojis/" + reaction.id + "." + ext);
 							// noinspection JSUnusedGlobalSymbols
 							return templateReactionCustom.apply({ url, n: reaction.n, c: reaction.c });

app/Resources/Viewer/scripts/dom.mjs

@@ -8,9 +8,12 @@ const HTML_ENTITY_MAP = {
 
 const HTML_ENTITY_REGEX = /[&<>"']/g;
 
-class DOM {
+export default class {
 	/**
 	 * Returns a child element by its ID. Parent defaults to the entire document.
+	 * @param {string} id
+	 * @param {HTMLElement} [parent]
+	 * @returns {HTMLElement|null}
 	 */
 	static id(id, parent) {
 		return (parent || document).getElementById(id);
@@ -18,6 +21,9 @@ class DOM {
 	
 	/**
 	 * Returns an array of all child elements containing the specified class. Parent defaults to the entire document.
+	 * @param {string} cls
+	 * @param {HTMLElement} [parent]
+	 * @returns {HTMLElement[]}
 	 */
 	static cls(cls, parent) {
 		return Array.prototype.slice.call((parent || document).getElementsByClassName(cls));
@@ -25,6 +31,9 @@ class DOM {
 	
 	/**
 	 * Returns an array of all child elements that have the specified tag. Parent defaults to the entire document.
+	 * @param {string} tag
+	 * @param {HTMLElement} [parent]
+	 * @returns {HTMLElement[]}
 	 */
 	static tag(tag, parent) {
 		return Array.prototype.slice.call((parent || document).getElementsByTagName(tag));
@@ -32,6 +41,9 @@ class DOM {
 	
 	/**
 	 * Returns the first child element containing the specified class. Parent defaults to the entire document.
+	 * @param {string} cls
+	 * @param {HTMLElement} [parent]
+	 * @returns {HTMLElement}
 	 */
 	static fcls(cls, parent) {
 		return (parent || document).getElementsByClassName(cls)[0];

app/Resources/Viewer/scripts/gui.mjs

@@ -1,10 +1,16 @@
-const GUI = (function() {
+import dom from "./dom.mjs";
+import discord from "./discord.mjs";
+import settings from "./settings.mjs";
+import state from "./state.mjs";
+
+export default (function() {
 	let eventOnOptMessagesPerPageChanged;
 	let eventOnOptMessageFilterChanged;
 	let eventOnNavButtonClicked;
 	
 	const getActiveFilter = function() {
-		const active = DOM.fcls("active", DOM.id("opt-filter-list"));
+		/** @type HTMLSelectElement */
+		const active = dom.fcls("active", dom.id("opt-filter-list"));
 		
 		return active && active.value !== "" ? {
 			"type": active.getAttribute("data-filter-type"),
@@ -17,12 +23,12 @@ const GUI = (function() {
 	};
 	
 	const showModal = function(width, html) {
-		const dialog = DOM.id("dialog");
+		const dialog = dom.id("dialog");
 		dialog.innerHTML = html;
 		dialog.style.width = width + "px";
 		dialog.style.marginLeft = (-width / 2) + "px";
 		
-		DOM.id("modal").classList.add("visible");
+		dom.id("modal").classList.add("visible");
 		return dialog;
 	};
 	
@@ -38,9 +44,9 @@ const GUI = (function() {
 <label><input id='dht-cfg-animemoji' type='checkbox'> Animated Emoji</label><br>`);
 		
 		const setupCheckBox = function(id, settingName) {
-			const ele = DOM.id(id);
+			const ele = dom.id(id);
-			ele.checked = SETTINGS[settingName];
+			ele.checked = settings[settingName];
-			ele.addEventListener("change", () => SETTINGS[settingName] = ele.checked);
+			ele.addEventListener("change", () => settings[settingName] = ele.checked);
 		};
 		
 		setupCheckBox("dht-cfg-imgpreviews", "enableImagePreviews");
@@ -65,20 +71,20 @@ const GUI = (function() {
 		// ---------
 		
 		setup() {
-			const inputMessageFilter = DOM.id("opt-messages-filter");
+			const inputMessageFilter = dom.id("opt-messages-filter");
-			const containerFilterList = DOM.id("opt-filter-list");
+			const containerFilterList = dom.id("opt-filter-list");
 			
 			const resetActiveFilter = function() {
 				inputMessageFilter.value = "";
 				inputMessageFilter.dispatchEvent(new Event("change"));
 				
-				DOM.id("opt-filter-contents").value = "";
+				dom.id("opt-filter-contents").value = "";
 			};
 			
 			inputMessageFilter.value = ""; // required to prevent browsers from remembering old value
 			
 			inputMessageFilter.addEventListener("change", () => {
-				DOM.cls("active", containerFilterList).forEach(ele => ele.classList.remove("active"));
+				dom.cls("active", containerFilterList).forEach(ele => ele.classList.remove("active"));
 				
 				if (inputMessageFilter.value) {
 					containerFilterList.querySelector("[data-filter-type='" + inputMessageFilter.value + "']").classList.add("active");
@@ -91,11 +97,11 @@ const GUI = (function() {
 				ele.addEventListener(ele.tagName === "SELECT" ? "change" : "input", () => triggerFilterChanged());
 			});
 			
-			DOM.id("opt-messages-per-page").addEventListener("change", () => {
+			dom.id("opt-messages-per-page").addEventListener("change", () => {
 				eventOnOptMessagesPerPageChanged && eventOnOptMessagesPerPageChanged();
 			});
 			
-			DOM.tag("button", DOM.fcls("nav")).forEach(button => {
+			dom.tag("button", dom.fcls("nav")).forEach(button => {
 				button.disabled = true;
 				
 				button.addEventListener("click", () => {
@@ -103,34 +109,34 @@ const GUI = (function() {
 				});
 			});
 			
-			DOM.id("btn-settings").addEventListener("click", () => {
+			dom.id("btn-settings").addEventListener("click", () => {
 				showSettingsModal();
 			});
 			
-			DOM.id("btn-about").addEventListener("click", () => {
+			dom.id("btn-about").addEventListener("click", () => {
 				showInfoModal();
 			});
 			
-			DOM.id("messages").addEventListener("click", e => {
+			dom.id("messages").addEventListener("click", e => {
 				const jump = e.target.getAttribute("data-jump");
 				
 				if (jump) {
 					resetActiveFilter();
 					
-					const index = STATE.navigateToMessage(jump);
+					const index = state.navigateToMessage(jump);
 					
 					if (index === -1) {
 						alert("Message not found.");
 					}
 					else {
-						DOM.id("messages").children[index].scrollIntoView();
+						dom.id("messages").children[index].scrollIntoView();
 					}
 				}
 			});
 			
-			DOM.id("overlay").addEventListener("click", () => {
+			dom.id("overlay").addEventListener("click", () => {
-				DOM.id("modal").classList.remove("visible");
+				dom.id("modal").classList.remove("visible");
-				DOM.id("dialog").innerHTML = "";
+				dom.id("dialog").innerHTML = "";
 			});
 		},
 		
@@ -168,19 +174,19 @@ const GUI = (function() {
 		 */
 		getOptionMessagesPerPage() {
 			/** @type HTMLInputElement */
-			const messagesPerPage = DOM.id("opt-messages-per-page");
+			const messagesPerPage = dom.id("opt-messages-per-page");
 			return parseInt(messagesPerPage.value, 10);
 		},
 		
 		updateNavigation(currentPage, totalPages) {
-			DOM.id("nav-page-current").innerHTML = currentPage;
+			dom.id("nav-page-current").innerHTML = currentPage;
-			DOM.id("nav-page-total").innerHTML = totalPages || "?";
+			dom.id("nav-page-total").innerHTML = totalPages || "?";
 			
-			DOM.id("nav-first").disabled = currentPage === 1;
+			dom.id("nav-first").disabled = currentPage === 1;
-			DOM.id("nav-prev").disabled = currentPage === 1;
+			dom.id("nav-prev").disabled = currentPage === 1;
-			DOM.id("nav-pick").disabled = (totalPages || 0) <= 1;
+			dom.id("nav-pick").disabled = (totalPages || 0) <= 1;
-			DOM.id("nav-next").disabled = currentPage === (totalPages || 1);
+			dom.id("nav-next").disabled = currentPage === (totalPages || 1);
-			DOM.id("nav-last").disabled = currentPage === (totalPages || 1);
+			dom.id("nav-last").disabled = currentPage === (totalPages || 1);
 		},
 		
 		// --------------
@@ -191,7 +197,7 @@ const GUI = (function() {
 		 * Updates the channel list and sets up their click events. The callback is triggered whenever a channel is selected, and takes the channel ID as its argument.
 		 */
 		updateChannelList(channels, selected, callback) {
-			const eleChannels = DOM.id("channels");
+			const eleChannels = dom.id("channels");
 			
 			if (!channels) {
 				eleChannels.innerHTML = "";
@@ -201,11 +207,11 @@ const GUI = (function() {
 					channels = channels.filter(channel => channel.msgcount > 0);
 				}
 				
-				eleChannels.innerHTML = channels.map(channel => DISCORD.getChannelHTML(channel)).join("");
+				eleChannels.innerHTML = channels.map(channel => discord.getChannelHTML(channel)).join("");
 				
 				Array.prototype.forEach.call(eleChannels.children, ele => {
 					ele.addEventListener("click", () => {
-						const currentChannel = DOM.fcls("active", eleChannels);
+						const currentChannel = dom.fcls("active", eleChannels);
 						
 						if (currentChannel) {
 							currentChannel.classList.remove("active");
@@ -224,12 +230,12 @@ const GUI = (function() {
 		},
 		
 		updateMessageList(messages) {
-			DOM.id("messages").innerHTML = messages ? messages.map(message => DISCORD.getMessageHTML(message)).join("") : "";
+			dom.id("messages").innerHTML = messages ? messages.map(message => discord.getMessageHTML(message)).join("") : "";
 		},
 		
 		updateUserList(users) {
 			/** @type HTMLSelectElement */
-			const eleSelect = DOM.id("opt-filter-user");
+			const eleSelect = dom.id("opt-filter-user");
 			
 			while (eleSelect.length > 1) {
 				eleSelect.remove(1);
@@ -249,7 +255,7 @@ const GUI = (function() {
 		},
 		
 		scrollMessagesToTop() {
-			DOM.id("messages").scrollTop = 0;
+			dom.id("messages").scrollTop = 0;
 		}
 	};
 })();

app/Resources/Viewer/scripts/processor.mjs

@@ -1,16 +1,16 @@
-const PROCESSOR = {};
+import discord from "./discord.mjs";
 
 // ------------------------
 // Global filter generators
 // ------------------------
 
-PROCESSOR.FILTER = {
+const filter = {
 	byUser: ((userindex) => message => message.u === userindex),
 	byTime: ((timeStart, timeEnd) => message => message.t >= timeStart && message.t <= timeEnd),
 	byContents: ((substr) => message => ("m" in message ? message.m : "").indexOf(substr) !== -1),
 	byRegex: ((regex) => message => regex.test("m" in message ? message.m : "")),
-	withImages: (() => message => (message.e && message.e.some(embed => embed.type === "image")) || (message.a && message.a.some(DISCORD.isImageAttachment))),
+	withImages: (() => message => (message.e && message.e.some(embed => embed.type === "image")) || (message.a && message.a.some(discord.isImageAttachment))),
-	withDownloads: (() => message => message.a && message.a.some(attachment => !DISCORD.isImageAttachment(attachment))),
+	withDownloads: (() => message => message.a && message.a.some(attachment => !discord.isImageAttachment(attachment))),
 	withEmbeds: (() => message => message.e && message.e.length > 0),
 	withAttachments: (() => message => message.a && message.a.length > 0),
 	isEdited: (() => message => ("te" in message) ? message.te : (message.f & 1) === 1)
@@ -20,7 +20,7 @@ PROCESSOR.FILTER = {
 // Global sorters
 // --------------
 
-PROCESSOR.SORTER = {
+const sorter = {
 	oldestToNewest: (key1, key2) => {
 		if (key1.length === key2.length) {
 			return key1 > key2 ? 1 : key1 < key2 ? -1 : 0;
@@ -39,3 +39,8 @@ PROCESSOR.SORTER = {
 		}
 	}
 };
+
+export default {
+	FILTER: filter,
+	SORTER: sorter
+};

app/Resources/Viewer/scripts/settings.mjs

@@ -1,4 +1,4 @@
-const SETTINGS = (function() {
+export default (function() {
 	/**
 	 * @type {{}}
 	 * @property {Function} onSettingsChanged

app/Resources/Viewer/scripts/state.mjs

@@ -1,10 +1,12 @@
+import settings from "./settings.mjs";
+import processor from "./processor.mjs";
+
 // noinspection FunctionWithInconsistentReturnsJS
-const STATE = (function() {
+export default (function() {
 	/**
 	 * @type {{}}
 	 * @property {{}} users
-	 * @property {String[]} userindex
+	 * @property {{}} servers
-	 * @property {{}[]} servers
 	 * @property {{}} channels
 	 */
 	let loadedFileMeta;
@@ -17,20 +19,16 @@ const STATE = (function() {
 	let currentPage;
 	let messagesPerPage;
 	
-	const getUser = function(index) {
+	const getUser = function(id) {
-		return loadedFileMeta.users[loadedFileMeta.userindex[index]] || { "name": "<unknown>" };
+		return loadedFileMeta.users[id] || { "name": "<unknown>" };
-	};
-	
-	const getUserId = function(index) {
-		return loadedFileMeta.userindex[index];
 	};
 	
 	const getUserList = function() {
 		return loadedFileMeta ? loadedFileMeta.users : [];
 	};
 	
-	const getServer = function(index) {
+	const getServer = function(id) {
-		return loadedFileMeta.servers[index] || { "name": "<unknown>", "type": "unknown" };
+		return loadedFileMeta.servers[id] || { "name": "<unknown>", "type": "unknown" };
 	};
 	
 	const generateChannelHierarchy = function() {
@@ -204,7 +202,7 @@ const STATE = (function() {
 			 */
 			const message = messages[key];
 			const user = getUser(message.u);
-			const avatar = user.avatar ? { id: getUserId(message.u), path: user.avatar } : null;
+			const avatar = user.avatar ? { id: message.u, path: user.avatar } : null;
 			
 			const obj = {
 				user,
@@ -232,7 +230,7 @@ const STATE = (function() {
 			if ("r" in message) {
 				const replyMessage = getMessageById(message.r);
 				const replyUser = replyMessage ? getUser(replyMessage.u) : null;
-				const replyAvatar = replyUser && replyUser.avatar ? { id: getUserId(replyMessage.u), path: replyUser.avatar } : null;
+				const replyAvatar = replyUser && replyUser.avatar ? { id: replyMessage.u, path: replyUser.avatar } : null;
 				
 				obj["reply"] = replyMessage ? {
 					"id": message.r,
@@ -290,20 +288,17 @@ const STATE = (function() {
 			eventOnUsersRefreshed = callback;
 		},
 		
-		/**
+		uploadFile(meta, data) {
-		 * @param {{ meta, data }} file
-		 */
-		uploadFile(file) {
 			if (loadedFileMeta != null) {
 				throw "A file is already loaded!";
 			}
 			
-			if (!file || typeof file.meta !== "object" || typeof file.data !== "object") {
+			if (typeof meta !== "object" || typeof data !== "object") {
 				throw "Invalid file format!";
 			}
 			
-			loadedFileMeta = file.meta;
+			loadedFileMeta = meta;
-			loadedFileData = file.data;
+			loadedFileData = data;
 			loadedMessages = null;
 			
 			selectedChannel = null;
@@ -313,7 +308,7 @@ const STATE = (function() {
 			triggerChannelsRefreshed();
 			triggerMessagesRefreshed();
 			
-			SETTINGS.onSettingsChanged(() => triggerMessagesRefreshed());
+			settings.onSettingsChanged(() => triggerMessagesRefreshed());
 		},
 		
 		getChannelName(channel) {
@@ -335,7 +330,7 @@ const STATE = (function() {
 			currentPage = 1;
 			selectedChannel = channel;
 			
-			loadedMessages = getFilteredMessageKeys(channel).sort(PROCESSOR.SORTER.oldestToNewest);
+			loadedMessages = getFilteredMessageKeys(channel).sort(processor.SORTER.oldestToNewest);
 			triggerMessagesRefreshed();
 		},
 		
@@ -416,23 +411,23 @@ const STATE = (function() {
 		setActiveFilter(filter) {
 			switch (filter ? filter.type : "") {
 				case "user":
-					filterFunction = PROCESSOR.FILTER.byUser(loadedFileMeta.userindex.indexOf(filter.value));
+					filterFunction = processor.FILTER.byUser(loadedFileMeta.userindex.indexOf(filter.value));
 					break;
 				
 				case "contents":
-					filterFunction = PROCESSOR.FILTER.byContents(filter.value);
+					filterFunction = processor.FILTER.byContents(filter.value);
 					break;
 				
 				case "withimages":
-					filterFunction = PROCESSOR.FILTER.withImages();
+					filterFunction = processor.FILTER.withImages();
 					break;
 				
 				case "withdownloads":
-					filterFunction = PROCESSOR.FILTER.withDownloads();
+					filterFunction = processor.FILTER.withDownloads();
 					break;
 				
 				case "edited":
-					filterFunction = PROCESSOR.FILTER.isEdited();
+					filterFunction = processor.FILTER.isEdited();
 					break;
 				
 				default:

app/Resources/Viewer/scripts/template.mjs

@@ -1,6 +1,8 @@
+import dom from "./dom.mjs";
+
 const TEMPLATE_REGEX = /{([^{}]+?)}/g;
 
-class TEMPLATE {
+export default class {
 	constructor(contents) {
 		this.contents = contents;
 	};
@@ -11,10 +13,10 @@ class TEMPLATE {
 			
 			if (processor) {
 				const updated = processor(match, value);
-				return typeof updated === "undefined" ? DOM.escapeHTML(value) : updated;
+				return typeof updated === "undefined" ? dom.escapeHTML(value) : updated;
 			}
 			
-			return DOM.escapeHTML(value);
+			return dom.escapeHTML(value);
 		});
 	}
 }

app/Resources/Viewer/styles/channels.css

@@ -3,18 +3,24 @@
   min-width: 215px;
   max-width: 300px;
   overflow-y: auto;
+  color: #eee;
   background-color: #1c1e22;
+  font-size: 15px;
 }
 
-#channels > div {
+#channels > div.loading {
+  margin: 0 auto;
+  width: 150px;
+  height: 150px;
+}
+
+#channels > div.channel {
   cursor: pointer;
   padding: 10px 12px;
-  color: #eee;
-  font-size: 15px;
   border-bottom: 1px solid #333333;
 }
 
-#channels > div:hover, #channels > div.active {
+#channels > div.channel:hover, #channels > div.channel.active {
   background-color: #282b30;
 }
 

app/Resources/Viewer/styles/main.css

@@ -11,3 +11,20 @@ body {
   display: flex;
   flex-direction: row;
 }
+
+.loading {
+  position: relative;
+  --loading-backdrop: rgba(0, 0, 0, 0);
+}
+
+.loading::after {
+  content: "";
+  background: var(--loading-backdrop)
+  url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 300 300' preserveAspectRatio='xMidYMid'%3E %3Ccircle cx='150' cy='150' fill='none' stroke='%237983f5' stroke-width='8' r='42' stroke-dasharray='198 68'%3E %3CanimateTransform attributeName='transform' type='rotate' repeatCount='indefinite' dur='1.25s' values='0 150 150;360 150 150' keyTimes='0;1' /%3E %3C/circle%3E %3C/svg%3E")
+  no-repeat center center;
+  position: absolute;
+  top: 0;
+  left: 0;
+  width: 100%;
+  height: 100%;
+}

app/Resources/Viewer/styles/messages.css

@@ -107,23 +107,11 @@
 }
 
 .message .thumbnail {
-  position: relative;
+  --loading-backdrop: rgba(0, 0, 0, 0.75);
   max-width: calc(100% - 20px);
   max-height: 320px;
 }
 
-.message .thumbnail.loading::after {
-  content: "";
-  background: rgba(0, 0, 0, 0.75)
-              url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 300 300' preserveAspectRatio='xMidYMid'%3E %3Ccircle cx='150' cy='150' fill='none' stroke='%237983f5' stroke-width='8' r='42' stroke-dasharray='198 68'%3E %3CanimateTransform attributeName='transform' type='rotate' repeatCount='indefinite' dur='1.25s' values='0 150 150;360 150 150' keyTimes='0;1' /%3E %3C/circle%3E %3C/svg%3E")
-              no-repeat center center;
-  position: absolute;
-  top: 0;
-  left: 0;
-  width: 100%;
-  height: 100%;
-}
-
 .message .thumbnail img {
   width: auto;
   max-width: 100%;

app/Server/Data/DownloadWithData.cs

@@ -1,3 +0,0 @@
-namespace DHT.Server.Data;
-
-public readonly record struct DownloadWithData(Download Download, byte[]? Data);

app/Server/Database/DatabaseExtensions.cs

@@ -26,7 +26,9 @@ public static class DatabaseExtensions {
 		await target.Messages.Add(batchedMessages);
 
 		await foreach (var download in source.Downloads.Get()) {
-			await target.Downloads.AddDownload(await source.Downloads.HydrateWithData(download));
+			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/Export/Snowflake.cs

@@ -1,3 +1,5 @@
 namespace DHT.Server.Database.Export;
 
-readonly record struct Snowflake(ulong Id);
+readonly record struct Snowflake(ulong Id) {
+	public static implicit operator Snowflake(ulong id) => new (id);
+}

app/Server/Database/Export/ViewerJson.cs

@@ -3,14 +3,10 @@ using System.Text.Json.Serialization;
 
 namespace DHT.Server.Database.Export;
 
-sealed class ViewerJson {
+static class ViewerJson {
-	public required JsonMeta Meta { get; init; }
-	public required Dictionary<Snowflake, Dictionary<Snowflake, JsonMessage>> Data { get; init; }
-
 	public sealed class JsonMeta {
 		public required Dictionary<Snowflake, JsonUser> Users { get; init; }
-		public required List<Snowflake> Userindex { get; init; }
+		public required Dictionary<Snowflake, JsonServer> Servers { get; init; }
-		public required List<JsonServer> Servers { get; init; }
 		public required Dictionary<Snowflake, JsonChannel> Channels { get; init; }
 	}
 	
@@ -30,7 +26,7 @@ sealed class ViewerJson {
 	}
 
 	public sealed class JsonChannel {
-		public required int Server { get; init; }
+		public required Snowflake Server { get; init; }
 		public required string Name { get; init; }
 		
 		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
@@ -47,7 +43,9 @@ sealed class ViewerJson {
 	}
 
 	public sealed class JsonMessage {
-		public required int U { get; init; }
+		public required Snowflake Id { get; init; }
+		public required Snowflake C { get; init; }
+		public required Snowflake U { get; init; }
 		public required long T { get; init; }
 
 		[JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]

app/Server/Database/Export/ViewerJsonExport.cs

@@ -2,7 +2,9 @@ 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.Tasks;
 using DHT.Server.Data;
 using DHT.Server.Data.Filters;
@@ -10,109 +12,93 @@ using DHT.Utils.Logging;
 
 namespace DHT.Server.Database.Export;
 
-public static class ViewerJsonExport {
+static class ViewerJsonExport {
 	private static readonly Log Log = Log.ForType(typeof(ViewerJsonExport));
 
-	public static async Task Generate(Stream stream, IDatabaseFile db, MessageFilter? filter = null) {
+	public static async Task GetMetadata(Stream stream, IDatabaseFile db, MessageFilter? filter = null, CancellationToken cancellationToken = default) {
 		var perf = Log.Start();
 
-		var includedUserIds = new HashSet<ulong>();
+		var includedChannels = new List<Channel>();
-		var includedChannelIds = new HashSet<ulong>();
 		var includedServerIds = new HashSet<ulong>();
 
-		var includedMessages = await db.Messages.Get(filter).ToListAsync();
+		var channelIdFilter = filter?.ChannelIds;
-		var includedChannels = new List<Channel>();
 
-		foreach (var message in includedMessages) {
+		await foreach (var channel in db.Channels.Get(cancellationToken)) {
-			includedUserIds.Add(message.Sender);
+			if (channelIdFilter == null || channelIdFilter.Contains(channel.Id)) {
-			includedChannelIds.Add(message.Channel);
-		}
-
-		await foreach (var channel in db.Channels.Get()) {
-			if (includedChannelIds.Contains(channel.Id)) {
 				includedChannels.Add(channel);
 				includedServerIds.Add(channel.Server);
 			}
 		}
 
-		var (users, userIndex, userIndices) = await GenerateUserList(db, includedUserIds);
+		var users = await GenerateUserList(db, cancellationToken);
-		var (servers, serverIndices) = await GenerateServerList(db, includedServerIds);
+		var servers = await GenerateServerList(db, includedServerIds, cancellationToken);
-		var channels = GenerateChannelList(includedChannels, serverIndices);
+		var channels = GenerateChannelList(includedChannels);
+
+		var meta = new ViewerJson.JsonMeta {
+			Users = users,
+			Servers = servers,
+			Channels = channels
+		};
 
 		perf.Step("Collect database data");
 
-		var value = new ViewerJson {
+		await JsonSerializer.SerializeAsync(stream, meta, ViewerJsonMetadataContext.Default.JsonMeta, cancellationToken);
-			Meta = new ViewerJson.JsonMeta {
-				Users = users,
-				Userindex = userIndex,
-				Servers = servers,
-				Channels = channels
-			},
-			Data = GenerateMessageList(includedMessages, userIndices)
-		};
-
-		perf.Step("Generate value object");
-
-		await JsonSerializer.SerializeAsync(stream, value, ViewerJsonContext.Default.ViewerJson);
 
 		perf.Step("Serialize to JSON");
 		perf.End();
 	}
 
-	private static async Task<(Dictionary<Snowflake, ViewerJson.JsonUser> Users, List<Snowflake> UserIndex, Dictionary<ulong, int> UserIndices)> GenerateUserList(IDatabaseFile db, HashSet<ulong> userIds) {
+	public static async Task GetMessages(Stream stream, IDatabaseFile db, MessageFilter? filter = null, CancellationToken cancellationToken = default) {
+		var perf = Log.Start();
+
+		ReadOnlyMemory<byte> newLine = "\n"u8.ToArray();
+		
+		await foreach(var message in GenerateMessageList(db, filter, cancellationToken)) {
+			await JsonSerializer.SerializeAsync(stream, message, ViewerJsonMessageContext.Default.JsonMessage, cancellationToken);
+			await stream.WriteAsync(newLine, cancellationToken);
+		}
+
+		perf.Step("Generate and serialize messages to JSON");
+		perf.End();
+	}
+
+	private static async Task<Dictionary<Snowflake, ViewerJson.JsonUser>> GenerateUserList(IDatabaseFile db, CancellationToken cancellationToken) {
 		var users = new Dictionary<Snowflake, ViewerJson.JsonUser>();
-		var userIndex = new List<Snowflake>();
-		var userIndices = new Dictionary<ulong, int>();
 
-		await foreach (var user in db.Users.Get()) {
+		await foreach (var user in db.Users.Get(cancellationToken)) {
-			var id = user.Id;
+			users[user.Id] = new ViewerJson.JsonUser {
-			if (!userIds.Contains(id)) {
-				continue;
-			}
-
-			var idSnowflake = new Snowflake(id);
-			userIndices[id] = users.Count;
-			userIndex.Add(idSnowflake);
-			
-			users[idSnowflake] = new ViewerJson.JsonUser {
 				Name = user.Name,
 				Avatar = user.AvatarUrl,
 				Tag = user.Discriminator
 			};
 		}
 
-		return (users, userIndex, userIndices);
+		return users;
 	}
 
-	private static async Task<(List<ViewerJson.JsonServer> Servers, Dictionary<ulong, int> ServerIndices)> GenerateServerList(IDatabaseFile db, HashSet<ulong> serverIds) {
+	private static async Task<Dictionary<Snowflake, ViewerJson.JsonServer>> GenerateServerList(IDatabaseFile db, HashSet<ulong> serverIds, CancellationToken cancellationToken) {
-		var servers = new List<ViewerJson.JsonServer>();
+		var servers = new Dictionary<Snowflake, ViewerJson.JsonServer>();
-		var serverIndices = new Dictionary<ulong, int>();
 
-		await foreach (var server in db.Servers.Get()) {
+		await foreach (var server in db.Servers.Get(cancellationToken)) {
-			var id = server.Id;
+			if (!serverIds.Contains(server.Id)) {
-			if (!serverIds.Contains(id)) {
 				continue;
 			}
 
-			serverIndices[id] = servers.Count;
+			servers[server.Id] = new ViewerJson.JsonServer {
-			
-			servers.Add(new ViewerJson.JsonServer {
 				Name = server.Name,
 				Type = ServerTypes.ToJsonViewerString(server.Type)
-			});
+			};
 		}
 
-		return (servers, serverIndices);
+		return servers;
 	}
 
-	private static Dictionary<Snowflake, ViewerJson.JsonChannel> GenerateChannelList(List<Channel> includedChannels, Dictionary<ulong, int> serverIndices) {
+	private static Dictionary<Snowflake, ViewerJson.JsonChannel> GenerateChannelList(List<Channel> includedChannels) {
 		var channels = new Dictionary<Snowflake, ViewerJson.JsonChannel>();
 
 		foreach (var channel in includedChannels) {
-			var channelIdSnowflake = new Snowflake(channel.Id);
+			channels[channel.Id] = new ViewerJson.JsonChannel {
-			
+				Server = channel.Server,
-			channels[channelIdSnowflake] = new ViewerJson.JsonChannel {
-				Server = serverIndices[channel.Server],
 				Name = channel.Name,
 				Parent = channel.ParentId?.ToString(),
 				Position = channel.Position,
@@ -124,51 +110,40 @@ public static class ViewerJsonExport {
 		return channels;
 	}
 
-	private static Dictionary<Snowflake, Dictionary<Snowflake, ViewerJson.JsonMessage>> GenerateMessageList(List<Message> includedMessages, Dictionary<ulong, int> userIndices) {
+	private static async IAsyncEnumerable<ViewerJson.JsonMessage> GenerateMessageList(IDatabaseFile db, MessageFilter? filter, [EnumeratorCancellation] CancellationToken cancellationToken) {
-		var data = new Dictionary<Snowflake, Dictionary<Snowflake, ViewerJson.JsonMessage>>();
+		await foreach (var message in db.Messages.Get(filter, cancellationToken)) {
+			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(),
 
-		foreach (var grouping in includedMessages.GroupBy(static message => message.Channel)) {
+				A = message.Attachments.IsEmpty ? null : message.Attachments.Select(static attachment => {
-			var channelIdSnowflake = new Snowflake(grouping.Key);
+					var a = new ViewerJson.JsonMessageAttachment {
-			var channelData = new Dictionary<Snowflake, ViewerJson.JsonMessage>();
+						Url = attachment.DownloadUrl,
+						Name = Uri.TryCreate(attachment.NormalizedUrl, UriKind.Absolute, out var uri) ? Path.GetFileName(uri.LocalPath) : attachment.NormalizedUrl
+					};
 
-			foreach (var message in grouping) {
+					if (attachment is { Width: not null, Height: not null }) {
-				var messageIdSnowflake = new Snowflake(message.Id);
+						a.Width = attachment.Width;
+						a.Height = attachment.Height;
+					}
 
-				channelData[messageIdSnowflake] = new ViewerJson.JsonMessage {
+					return a;
-					U = userIndices[message.Sender],
+				}).ToArray(),
-					T = message.Timestamp,
-					M = string.IsNullOrEmpty(message.Text) ? null : message.Text,
-					Te = message.EditTimestamp,
-					R = message.RepliedToId?.ToString(),
 
-					A = message.Attachments.IsEmpty ? null : message.Attachments.Select(static attachment => {
+				E = message.Embeds.IsEmpty ? null : message.Embeds.Select(static embed => embed.Json).ToArray(),
-						var a = new ViewerJson.JsonMessageAttachment {
-							Url = attachment.DownloadUrl,
-							Name = Uri.TryCreate(attachment.NormalizedUrl, UriKind.Absolute, out var uri) ? Path.GetFileName(uri.LocalPath) : attachment.NormalizedUrl
-						};
 
-						if (attachment is { Width: not null, Height: not null }) {
+				Re = message.Reactions.IsEmpty ? null : message.Reactions.Select(static reaction => new ViewerJson.JsonMessageReaction {
-							a.Width = attachment.Width;
+					Id = reaction.EmojiId?.ToString(),
-							a.Height = attachment.Height;
+					N = reaction.EmojiName,
-						}
+					A = reaction.EmojiFlags.HasFlag(EmojiFlags.Animated),
-
+					C = reaction.Count
-						return a;
+				}).ToArray()
-					}).ToArray(),
+			};
-					
-					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(),
-						N = reaction.EmojiName,
-						A = reaction.EmojiFlags.HasFlag(EmojiFlags.Animated),
-						C = reaction.Count
-					}).ToArray()
-				};
-			}
-
-			data[channelIdSnowflake] = channelData;
 		}
-
-		return data;
 	}
 }

app/Server/Database/Export/ViewerJsonMessageContext.cs

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

app/Server/Database/Export/ViewerJsonMetadataContext.cs

@@ -7,5 +7,5 @@ namespace DHT.Server.Database.Export;
 	PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase,
 	GenerationMode = JsonSourceGenerationMode.Default
 )]
-[JsonSerializable(typeof(ViewerJson))]
+[JsonSerializable(typeof(ViewerJson.JsonMeta))]
-sealed partial class ViewerJsonContext : JsonSerializerContext;
+sealed partial class ViewerJsonMetadataContext : JsonSerializerContext;

app/Server/Database/Import/LegacyArchiveImport.cs

@@ -161,7 +161,7 @@ public static class LegacyArchiveImport {
 
 		var messagesObj = data.HasKey(channelIdStr) ? data.RequireObject(channelIdStr, DataPath) : (JsonElement?) null;
 		if (messagesObj == null) {
-			return Array.Empty<Message>();
+			return [];
 		}
 
 		return messagesObj.Value.EnumerateObject().Select(item => {

app/Server/Database/Repositories/IChannelRepository.cs

@@ -15,7 +15,7 @@ public interface IChannelRepository {
 	
 	Task<long> Count(CancellationToken cancellationToken = default);
 	
-	IAsyncEnumerable<Channel> Get();
+	IAsyncEnumerable<Channel> Get(CancellationToken cancellationToken = default);
 
 	internal sealed class Dummy : IChannelRepository {
 		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
@@ -28,7 +28,7 @@ public interface IChannelRepository {
 			return Task.FromResult(0L);
 		}
 
-		public IAsyncEnumerable<Channel> Get() {
+		public IAsyncEnumerable<Channel> Get(CancellationToken cancellationToken) {
 			return AsyncEnumerable.Empty<Channel>();
 		}
 	}

app/Server/Database/Repositories/IDownloadRepository.cs

@@ -1,10 +1,10 @@
 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;
@@ -14,7 +14,7 @@ namespace DHT.Server.Database.Repositories;
 public interface IDownloadRepository {
 	IObservable<long> TotalCount { get; }
 
-	Task AddDownload(DownloadWithData item);
+	Task AddDownload(Data.Download item, Stream? stream);
 
 	Task<long> Count(DownloadItemFilter filter, CancellationToken cancellationToken = default);
 	
@@ -22,9 +22,9 @@ public interface IDownloadRepository {
 	
 	IAsyncEnumerable<Data.Download> Get();
 
-	Task<DownloadWithData> HydrateWithData(Data.Download download);
+	Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor);
 	
-	Task<DownloadWithData?> GetSuccessfulDownloadWithData(string normalizedUrl);
+	Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, CancellationToken, Task> dataProcessor, CancellationToken cancellationToken = default);
 
 	IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, CancellationToken cancellationToken = default);
 	
@@ -35,7 +35,7 @@ public interface IDownloadRepository {
 	internal sealed class Dummy : IDownloadRepository {
 		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
 
-		public Task AddDownload(DownloadWithData item) {
+		public Task AddDownload(Data.Download item, Stream? stream) {
 			return Task.CompletedTask;
 		}
 
@@ -51,12 +51,12 @@ public interface IDownloadRepository {
 			return AsyncEnumerable.Empty<Data.Download>();
 		}
 
-		public Task<DownloadWithData> HydrateWithData(Data.Download download) {
+		public Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor) {
-			return Task.FromResult(new DownloadWithData(download, Data: null));
+			return Task.FromResult(false);
 		}
 
-		public Task<DownloadWithData?> GetSuccessfulDownloadWithData(string normalizedUrl) {
+		public Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, CancellationToken, Task> dataProcessor, CancellationToken cancellationToken) {
-			return Task.FromResult<DownloadWithData?>(null);
+			return Task.FromResult(false);
 		}
 
 		public IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, CancellationToken cancellationToken) {

app/Server/Database/Repositories/IMessageRepository.cs

@@ -16,7 +16,7 @@ public interface IMessageRepository {
 	
 	Task<long> Count(MessageFilter? filter = null, CancellationToken cancellationToken = default);
 	
-	IAsyncEnumerable<Message> Get(MessageFilter? filter = null);
+	IAsyncEnumerable<Message> Get(MessageFilter? filter = null, CancellationToken cancellationToken = default);
 	
 	IAsyncEnumerable<ulong> GetIds(MessageFilter? filter = null);
 	
@@ -33,7 +33,7 @@ public interface IMessageRepository {
 			return Task.FromResult(0L);
 		}
 
-		public IAsyncEnumerable<Message> Get(MessageFilter? filter) {
+		public IAsyncEnumerable<Message> Get(MessageFilter? filter, CancellationToken cancellationToken) {
 			return AsyncEnumerable.Empty<Message>();
 		}
 

app/Server/Database/Repositories/IServerRepository.cs

@@ -14,7 +14,7 @@ public interface IServerRepository {
 	
 	Task<long> Count(CancellationToken cancellationToken = default);
 	
-	IAsyncEnumerable<Data.Server> Get();
+	IAsyncEnumerable<Data.Server> Get(CancellationToken cancellationToken = default);
 
 	internal sealed class Dummy : IServerRepository {
 		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
@@ -27,7 +27,7 @@ public interface IServerRepository {
 			return Task.FromResult(0L);
 		}
 
-		public IAsyncEnumerable<Data.Server> Get() {
+		public IAsyncEnumerable<Data.Server> Get(CancellationToken cancellationToken) {
 			return AsyncEnumerable.Empty<Data.Server>();
 		}
 	}

app/Server/Database/Repositories/IUserRepository.cs

@@ -15,7 +15,7 @@ public interface IUserRepository {
 	
 	Task<long> Count(CancellationToken cancellationToken = default);
 	
-	IAsyncEnumerable<User> Get();
+	IAsyncEnumerable<User> Get(CancellationToken cancellationToken = default);
 
 	internal sealed class Dummy : IUserRepository {
 		public IObservable<long> TotalCount { get; } = Observable.Return(0L);
@@ -28,7 +28,7 @@ public interface IUserRepository {
 			return Task.FromResult(0L);
 		}
 
-		public IAsyncEnumerable<User> Get() {
+		public IAsyncEnumerable<User> Get(CancellationToken cancellationToken) {
 			return AsyncEnumerable.Empty<User>();
 		}
 	}

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

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Data;
@@ -19,9 +20,9 @@ sealed class SqliteChannelRepository : BaseSqliteRepository, IChannelRepository
 	}
 
 	public async Task Add(IReadOnlyList<Channel> channels) {
-		await using var conn = await pool.Take();
+		await using (var conn = await pool.Take()) {
+			await conn.BeginTransactionAsync();
 			
-		await using (var tx = await conn.BeginTransactionAsync()) {
 			await using var cmd = conn.Upsert("channels", [
 				("id", SqliteType.Integer),
 				("server", SqliteType.Integer),
@@ -43,7 +44,7 @@ sealed class SqliteChannelRepository : BaseSqliteRepository, IChannelRepository
 				await cmd.ExecuteNonQueryAsync();
 			}
 
-			await tx.CommitAsync();
+			await conn.CommitTransactionAsync();
 		}
 
 		UpdateTotalCount();
@@ -54,13 +55,13 @@ sealed class SqliteChannelRepository : BaseSqliteRepository, IChannelRepository
 		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM channels", static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
 	}
 
-	public async IAsyncEnumerable<Channel> Get() {
+	public async IAsyncEnumerable<Channel> Get([EnumeratorCancellation] CancellationToken cancellationToken) {
 		await using var conn = await pool.Take();
 
 		await using var cmd = conn.Command("SELECT id, server, name, parent_id, position, topic, nsfw FROM channels");
-		await using var reader = await cmd.ExecuteReaderAsync();
+		await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
 
-		while (await reader.ReadAsync()) {
+		while (await reader.ReadAsync(cancellationToken)) {
 			yield return new Channel {
 				Id = reader.GetUint64(0),
 				Server = reader.GetUint64(1),

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

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.IO;
 using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
@@ -14,15 +15,9 @@ using Microsoft.Data.Sqlite;
 
 namespace DHT.Server.Database.Sqlite.Repositories;
 
-sealed class SqliteDownloadRepository : BaseSqliteRepository, IDownloadRepository {
+sealed class SqliteDownloadRepository(SqliteConnectionPool pool) : BaseSqliteRepository(Log), IDownloadRepository {
 	private static readonly Log Log = Log.ForType<SqliteDownloadRepository>();
 
-	private readonly SqliteConnectionPool pool;
-
-	public SqliteDownloadRepository(SqliteConnectionPool pool) : base(Log) {
-		this.pool = pool;
-	}
-
 	internal sealed class NewDownloadCollector : IAsyncDisposable {
 		private readonly SqliteDownloadRepository repository;
 		private bool hasAdded = false;
@@ -66,11 +61,9 @@ sealed class SqliteDownloadRepository : BaseSqliteRepository, IDownloadRepositor
 		}
 	}
 
-	public async Task AddDownload(DownloadWithData item) {
+	public async Task AddDownload(Data.Download item, Stream? stream) {
-		var (download, data) = item;
-
 		await using (var conn = await pool.Take()) {
-			var tx = await conn.BeginTransactionAsync();
+			await conn.BeginTransactionAsync();
 			
 			await using var metadataCmd = conn.Upsert("download_metadata", [
 				("normalized_url", SqliteType.Text),
@@ -80,30 +73,37 @@ sealed class SqliteDownloadRepository : BaseSqliteRepository, IDownloadRepositor
 				("size", SqliteType.Integer),
 			]);
 
-			metadataCmd.Set(":normalized_url", download.NormalizedUrl);
+			metadataCmd.Set(":normalized_url", item.NormalizedUrl);
-			metadataCmd.Set(":download_url", download.DownloadUrl);
+			metadataCmd.Set(":download_url", item.DownloadUrl);
-			metadataCmd.Set(":status", (int) download.Status);
+			metadataCmd.Set(":status", (int) item.Status);
-			metadataCmd.Set(":type", download.Type);
+			metadataCmd.Set(":type", item.Type);
-			metadataCmd.Set(":size", download.Size);
+			metadataCmd.Set(":size", item.Size);
 			await metadataCmd.ExecuteNonQueryAsync();
 
-			if (data == null) {
+			if (stream == null) {
 				await using var deleteBlobCmd = conn.Command("DELETE FROM download_blobs WHERE normalized_url = :normalized_url");
-				deleteBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, download.NormalizedUrl);
+				deleteBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, item.NormalizedUrl);
 				await deleteBlobCmd.ExecuteNonQueryAsync();
 			}
 			else {
-				await using var upsertBlobCmd = conn.Upsert("download_blobs", [
+				await using var upsertBlobCmd = conn.Command(
-					("normalized_url", SqliteType.Text),
+					"""
-					("blob", SqliteType.Blob)
+					INSERT INTO download_blobs (normalized_url, blob)
-				]);
+					VALUES (:normalized_url, ZEROBLOB(:blob_length))
+					ON CONFLICT (normalized_url) DO UPDATE SET blob = excluded.blob
+					RETURNING rowid
+					"""
+				);
 				
-				upsertBlobCmd.Set(":normalized_url", download.NormalizedUrl);
+				upsertBlobCmd.AddAndSet(":normalized_url", SqliteType.Text, item.NormalizedUrl);
-				upsertBlobCmd.Set(":blob", data);
+				upsertBlobCmd.AddAndSet(":blob_length", SqliteType.Integer, item.Size);
-				await upsertBlobCmd.ExecuteNonQueryAsync();
+				long rowid = await upsertBlobCmd.ExecuteLongScalarAsync();
+
+				await using var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid);
+				await stream.CopyToAsync(blob);
 			}
 
-			await tx.CommitAsync();
+			await conn.CommitTransactionAsync();
 		}
 
 		UpdateTotalCount();
@@ -187,24 +187,35 @@ sealed class SqliteDownloadRepository : BaseSqliteRepository, IDownloadRepositor
 		}
 	}
 
-	public async Task<DownloadWithData> HydrateWithData(Data.Download download) {
+	public async Task<bool> GetDownloadData(string normalizedUrl, Func<Stream, Task> dataProcessor) {
 		await using var conn = await pool.Take();
 
-		await using var cmd = conn.Command("SELECT blob FROM download_blobs WHERE normalized_url = :url");
+		await using var cmd = conn.Command("SELECT rowid FROM download_blobs WHERE normalized_url = :normalized_url");
-		cmd.AddAndSet(":url", SqliteType.Text, download.NormalizedUrl);
+		cmd.AddAndSet(":normalized_url", SqliteType.Text, normalizedUrl);
 		
-		await using var reader = await cmd.ExecuteReaderAsync();
+		long rowid;
-		var data = await reader.ReadAsync() && !reader.IsDBNull(0) ? (byte[]) reader["blob"] : null;
 		
-		return new DownloadWithData(download, data);
+		await using (var reader = await cmd.ExecuteReaderAsync()) {
+			if (!await reader.ReadAsync()) {
+				return false;
+			}
+
+			rowid = reader.GetInt64(0);
+		}
+		
+		await using (var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid, readOnly: true)) {
+			await dataProcessor(blob);
+		}
+
+		return true;
 	}
 
-	public async Task<DownloadWithData?> GetSuccessfulDownloadWithData(string normalizedUrl) {
+	public async Task<bool> GetSuccessfulDownloadWithData(string normalizedUrl, Func<Data.Download, Stream, CancellationToken, Task> dataProcessor, CancellationToken cancellationToken) {
 		await using var conn = await pool.Take();
 
 		await using var cmd = conn.Command(
 			"""
-			SELECT dm.download_url, dm.type, db.blob FROM download_metadata dm
+			SELECT dm.download_url, dm.type, db.rowid FROM download_metadata dm
 			JOIN download_blobs db ON dm.normalized_url = db.normalized_url
 			WHERE dm.normalized_url = :normalized_url AND dm.status = :success IS NOT NULL
 			"""
@@ -213,19 +224,25 @@ sealed class SqliteDownloadRepository : BaseSqliteRepository, IDownloadRepositor
 		cmd.AddAndSet(":normalized_url", SqliteType.Text, normalizedUrl);
 		cmd.AddAndSet(":success", SqliteType.Integer, (int) DownloadStatus.Success);
 
-		await using var reader = await cmd.ExecuteReaderAsync();
+		string downloadUrl;
+		string? type;
+		long rowid;
 		
-		if (!await reader.ReadAsync()) {
+		await using (var reader = await cmd.ExecuteReaderAsync(cancellationToken)) {
-			return null;
+			if (!await reader.ReadAsync(cancellationToken)) {
+				return false;
+			}
+
+			downloadUrl = reader.GetString(0);
+			type = reader.IsDBNull(1) ? null : reader.GetString(1);
+			rowid = reader.GetInt64(2);
 		}
 		
-		var downloadUrl = reader.GetString(0);
+		await using (var blob = new SqliteBlob(conn.InnerConnection, "download_blobs", "blob", rowid, readOnly: true)) {
-		var type = reader.IsDBNull(1) ? null : reader.GetString(1);
+			await dataProcessor(new Data.Download(normalizedUrl, downloadUrl, DownloadStatus.Success, type, (ulong) blob.Length), blob, cancellationToken);
-		var data = (byte[]) reader[2];
+		}
-		var size = (ulong) data.LongLength;
-		var download = new Data.Download(normalizedUrl, downloadUrl, DownloadStatus.Success, type, size);
 
-		return new DownloadWithData(download, data);
+		return true;
 	}
 
 	public async IAsyncEnumerable<DownloadItem> PullPendingDownloadItems(int count, DownloadItemFilter filter, [EnumeratorCancellation] CancellationToken cancellationToken) {

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

@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Data;
@@ -39,7 +40,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 		}
 
 		await using (var conn = await pool.Take()) {
-			await using var tx = await conn.BeginTransactionAsync();
+			await conn.BeginTransactionAsync();
 
 			await using var messageCmd = conn.Upsert("messages", [
 				("message_id", SqliteType.Integer),
@@ -167,7 +168,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 				}
 			}
 
-			await tx.CommitAsync();
+			await conn.CommitTransactionAsync();
 			downloadCollector.OnCommitted();
 		}
 
@@ -183,11 +184,11 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM messages" + filter.GenerateConditions().BuildWhereClause(), static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
 	}
 
-	private sealed class MesageToManyCommand<T> : IAsyncDisposable {
+	private sealed class MessageToManyCommand<T> : IAsyncDisposable {
 		private readonly SqliteCommand cmd;
 		private readonly Func<SqliteDataReader, T> readItem;
 
-		public MesageToManyCommand(ISqliteConnection conn, string sql, Func<SqliteDataReader, T> readItem) {
+		public MessageToManyCommand(ISqliteConnection conn, string sql, Func<SqliteDataReader, T> readItem) {
 			this.cmd = conn.Command(sql);
 			this.cmd.Add(":message_id", SqliteType.Integer);
 
@@ -213,7 +214,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 		}
 	}
 
-	public async IAsyncEnumerable<Message> Get(MessageFilter? filter) {
+	public async IAsyncEnumerable<Message> Get(MessageFilter? filter, [EnumeratorCancellation] CancellationToken cancellationToken) {
 		await using var conn = await pool.Take();
 
 		const string AttachmentSql =
@@ -223,7 +224,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 			WHERE message_id = :message_id
 			""";
 
-		await using var attachmentCmd = new MesageToManyCommand<Attachment>(conn, AttachmentSql, static reader => new Attachment {
+		await using var attachmentCmd = new MessageToManyCommand<Attachment>(conn, AttachmentSql, static reader => new Attachment {
 			Id = reader.GetUint64(0),
 			Name = reader.GetString(1),
 			Type = reader.IsDBNull(2) ? null : reader.GetString(2),
@@ -241,7 +242,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 			WHERE message_id = :message_id
 			""";
 
-		await using var embedCmd = new MesageToManyCommand<Embed>(conn, EmbedSql, static reader => new Embed {
+		await using var embedCmd = new MessageToManyCommand<Embed>(conn, EmbedSql, static reader => new Embed {
 			Json = reader.GetString(0)
 		});
 
@@ -252,7 +253,7 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 			WHERE message_id = :message_id
 			""";
 
-		await using var reactionsCmd = new MesageToManyCommand<Reaction>(conn, ReactionSql, static reader => new Reaction {
+		await using var reactionsCmd = new MessageToManyCommand<Reaction>(conn, ReactionSql, static reader => new Reaction {
 			EmojiId = reader.IsDBNull(0) ? null : reader.GetUint64(0),
 			EmojiName = reader.IsDBNull(1) ? null : reader.GetString(1),
 			EmojiFlags = (EmojiFlags) reader.GetInt16(2),
@@ -269,9 +270,9 @@ sealed class SqliteMessageRepository : BaseSqliteRepository, IMessageRepository
 			 """
 		);
 
-		await using var reader = await messageCmd.ExecuteReaderAsync();
+		await using var reader = await messageCmd.ExecuteReaderAsync(cancellationToken);
 
-		while (await reader.ReadAsync()) {
+		while (await reader.ReadAsync(cancellationToken)) {
 			ulong messageId = reader.GetUint64(0);
 
 			yield return new Message {

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

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Data;
@@ -19,9 +20,9 @@ sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
 	}
 
 	public async Task Add(IReadOnlyList<Data.Server> servers) {
-		await using var conn = await pool.Take();
+		await using (var conn = await pool.Take()) {
+			await conn.BeginTransactionAsync();
 			
-		await using (var tx = await conn.BeginTransactionAsync()) {
 			await using var cmd = conn.Upsert("servers", [
 				("id", SqliteType.Integer),
 				("name", SqliteType.Text),
@@ -35,7 +36,7 @@ sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
 				await cmd.ExecuteNonQueryAsync();
 			}
 
-			await tx.CommitAsync();
+			await conn.CommitTransactionAsync();
 		}
 
 		UpdateTotalCount();
@@ -46,13 +47,13 @@ sealed class SqliteServerRepository : BaseSqliteRepository, IServerRepository {
 		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM servers", static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
 	}
 
-	public async IAsyncEnumerable<Data.Server> Get() {
+	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 reader = await cmd.ExecuteReaderAsync();
+		await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
 
-		while (await reader.ReadAsync()) {
+		while (await reader.ReadAsync(cancellationToken)) {
 			yield return new Data.Server {
 				Id = reader.GetUint64(0),
 				Name = reader.GetString(1),

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

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Data;
@@ -23,7 +24,7 @@ sealed class SqliteUserRepository : BaseSqliteRepository, IUserRepository {
 
 	public async Task Add(IReadOnlyList<User> users) {
 		await using (var conn = await pool.Take()) {
-			await using var tx = await conn.BeginTransactionAsync();
+			await conn.BeginTransactionAsync();
 
 			await using var cmd = conn.Upsert("users", [
 				("id", SqliteType.Integer),
@@ -46,7 +47,7 @@ sealed class SqliteUserRepository : BaseSqliteRepository, IUserRepository {
 				}
 			}
 
-			await tx.CommitAsync();
+			await conn.CommitTransactionAsync();
 			downloadCollector.OnCommitted();
 		}
 
@@ -58,13 +59,13 @@ sealed class SqliteUserRepository : BaseSqliteRepository, IUserRepository {
 		return await conn.ExecuteReaderAsync("SELECT COUNT(*) FROM users", static reader => reader?.GetInt64(0) ?? 0L, cancellationToken);
 	}
 
-	public async IAsyncEnumerable<User> Get() {
+	public async IAsyncEnumerable<User> Get([EnumeratorCancellation] CancellationToken cancellationToken) {
 		await using var conn = await pool.Take();
 
 		await using var cmd = conn.Command("SELECT id, name, avatar_url, discriminator FROM users");
-		await using var reader = await cmd.ExecuteReaderAsync();
+		await using var reader = await cmd.ExecuteReaderAsync(cancellationToken);
 
-		while (await reader.ReadAsync()) {
+		while (await reader.ReadAsync(cancellationToken)) {
 			yield return new User {
 				Id = reader.GetUint64(0),
 				Name = reader.GetString(1),

app/Server/Database/Sqlite/Schema/SqliteSchemaUpgradeTo6.cs

@@ -1,5 +1,4 @@
 using System.Collections.Generic;
-using System.Data.Common;
 using System.Threading.Tasks;
 using DHT.Server.Database.Sqlite.Utils;
 using DHT.Server.Download;
@@ -39,7 +38,7 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 			}
 		}
 
-		await using var tx = await conn.BeginTransactionAsync();
+		await conn.BeginTransactionAsync();
 
 		int totalUrls = normalizedUrls.Count;
 		int processedUrls = -1;
@@ -61,7 +60,7 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 
 		await reporter.SubWork("Updating URLs...", totalUrls, totalUrls);
 
-		await tx.CommitAsync();
+		await conn.CommitTransactionAsync();
 	}
 
 	private async Task NormalizeDownloadUrls(ISqliteConnection conn, ISchemaUpgradeCallbacks.IProgressReporter reporter) {
@@ -84,26 +83,23 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 		}
 
 		await conn.ExecuteAsync("PRAGMA cache_size = -20000");
+		await conn.BeginTransactionAsync();
 		
-		DbTransaction tx;
+		await reporter.SubWork("Deleting duplicates...", 0, 0);
 
-		await using (tx = await conn.BeginTransactionAsync()) {
+		await using (var deleteCmd = conn.Delete("downloads", ("url", SqliteType.Text))) {
-			await reporter.SubWork("Deleting duplicates...", 0, 0);
+			foreach (var duplicateUrl in duplicateUrlsToDelete) {
-
+				deleteCmd.Set(":url", duplicateUrl);
-			await using (var deleteCmd = conn.Delete("downloads", ("url", SqliteType.Text))) {
+				await deleteCmd.ExecuteNonQueryAsync();
-				foreach (var duplicateUrl in duplicateUrlsToDelete) {
-					deleteCmd.Set(":url", duplicateUrl);
-					await deleteCmd.ExecuteNonQueryAsync();
-				}
 			}
-
-			await tx.CommitAsync();
 		}
 
+		await conn.CommitTransactionAsync();
+
 		int totalUrls = normalizedUrlsToOriginalUrls.Count;
 		int processedUrls = -1;
 
-		tx = await conn.BeginTransactionAsync();
+		await conn.BeginTransactionAsync();
 
 		await using (var updateCmd = conn.Command("UPDATE downloads SET download_url = :download_url, url = :normalized_url WHERE url = :download_url")) {
 			updateCmd.Add(":normalized_url", SqliteType.Text);
@@ -115,11 +111,10 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 
 					// Not proper way of dealing with transactions, but it avoids a long commit at the end.
 					// Schema upgrades are already non-atomic anyways, so this doesn't make it worse.
-					await tx.CommitAsync();
+					await conn.CommitTransactionAsync();
-					await tx.DisposeAsync();
 
-					tx = await conn.BeginTransactionAsync();
+					await conn.BeginTransactionAsync();
-					updateCmd.Transaction = (SqliteTransaction) tx;
+					conn.AssignActiveTransaction(updateCmd);
 				}
 
 				updateCmd.Set(":normalized_url", normalizedUrl);
@@ -130,8 +125,7 @@ sealed class SqliteSchemaUpgradeTo6 : ISchemaUpgrade {
 
 		await reporter.SubWork("Updating URLs...", totalUrls, totalUrls);
 
-		await tx.CommitAsync();
+		await conn.CommitTransactionAsync();
-		await tx.DisposeAsync();
 
 		await conn.ExecuteAsync("PRAGMA cache_size = -2000");
 	}

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

@@ -37,7 +37,7 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 
 		await reporter.SubWork("Processing downloaded files...", 0, totalFiles);
 
-		var tx = await conn.BeginTransactionAsync();
+		await conn.BeginTransactionAsync();
 
 		await using (var insertCmd = conn.Command("INSERT INTO download_blobs (normalized_url, blob) SELECT normalized_url, blob FROM downloads WHERE normalized_url = :normalized_url"))
 		await using (var deleteCmd = conn.Command("DELETE FROM downloads WHERE normalized_url = :normalized_url")) {
@@ -50,12 +50,11 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 
 					// Not proper way of dealing with transactions, but it avoids a long commit at the end.
 					// Schema upgrades are already non-atomic anyways, so this doesn't make it worse.
-					await tx.CommitAsync();
+					await conn.CommitTransactionAsync();
-					await tx.DisposeAsync();
 					
-					tx = await conn.BeginTransactionAsync();
+					await conn.BeginTransactionAsync();
-					insertCmd.Transaction = (SqliteTransaction) tx;
+					conn.AssignActiveTransaction(insertCmd);
-					deleteCmd.Transaction = (SqliteTransaction) tx;
+					conn.AssignActiveTransaction(deleteCmd);
 				}
 
 				insertCmd.Set(":normalized_url", url);
@@ -68,8 +67,7 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 
 		await reporter.SubWork("Processing downloaded files...", totalFiles, totalFiles);
 
-		await tx.CommitAsync();
+		await conn.CommitTransactionAsync();
-		await tx.DisposeAsync();
 	}
 
 	private async Task<List<string>> GetDownloadedFileUrls(ISqliteConnection conn) {
@@ -111,45 +109,45 @@ sealed class SqliteSchemaUpgradeTo7 : ISchemaUpgrade {
 			await insertCmd.ExecuteNonQueryAsync();
 		}
 
-		await using (var tx = await conn.BeginTransactionAsync()) {
+		await conn.BeginTransactionAsync();
-			await using var insertCmd = conn.Command("INSERT OR IGNORE INTO download_metadata (normalized_url, download_url, status, type, size) VALUES (:normalized_url, :download_url, :status, :type, :size)");
-			insertCmd.Add(":normalized_url", SqliteType.Text);
-			insertCmd.Add(":download_url", SqliteType.Text);
-			insertCmd.Add(":status", SqliteType.Integer);
-			insertCmd.Add(":type", SqliteType.Text);
-			insertCmd.Add(":size", SqliteType.Integer);
 
-			await reporter.SubWork("Processing embeds...", 1, 4);
+		await using var insertCmd = conn.Command("INSERT OR IGNORE INTO download_metadata (normalized_url, download_url, status, type, size) VALUES (:normalized_url, :download_url, :status, :type, :size)");
+		insertCmd.Add(":normalized_url", SqliteType.Text);
+		insertCmd.Add(":download_url", SqliteType.Text);
+		insertCmd.Add(":status", SqliteType.Integer);
+		insertCmd.Add(":type", SqliteType.Text);
+		insertCmd.Add(":size", SqliteType.Integer);
 
-			await using (var embedCmd = conn.Command("SELECT json FROM embeds")) {
+		await reporter.SubWork("Processing embeds...", 1, 4);
-				await using var reader = await embedCmd.ExecuteReaderAsync();
 
-				while (await reader.ReadAsync()) {
+		await using (var embedCmd = conn.Command("SELECT json FROM embeds")) {
-					await InsertDownload(insertCmd, await DownloadLinkExtractor.TryFromEmbedJson(reader.GetStream(0)));
+			await using var reader = await embedCmd.ExecuteReaderAsync();
-				}
+
+			while (await reader.ReadAsync()) {
+				await InsertDownload(insertCmd, await DownloadLinkExtractor.TryFromEmbedJson(reader.GetStream(0)));
 			}
-
-			await reporter.SubWork("Processing users...", 2, 4);
-			
-			await using (var avatarCmd = conn.Command("SELECT id, avatar_url FROM users WHERE avatar_url IS NOT NULL")) {
-				await using var reader = await avatarCmd.ExecuteReaderAsync();
-
-				while (await reader.ReadAsync()) {
-					await InsertDownload(insertCmd, DownloadLinkExtractor.FromUserAvatar(reader.GetUint64(0), reader.GetString(1)));
-				}
-			}
-			
-			await reporter.SubWork("Processing reactions...", 3, 4);
-			
-			await using (var avatarCmd = conn.Command("SELECT DISTINCT emoji_id, emoji_flags FROM reactions WHERE emoji_id IS NOT NULL")) {
-				await using var reader = await avatarCmd.ExecuteReaderAsync();
-
-				while (await reader.ReadAsync()) {
-					await InsertDownload(insertCmd, DownloadLinkExtractor.FromEmoji(reader.GetUint64(0), (EmojiFlags) reader.GetInt16(1)));
-				}
-			}
-			
-			await tx.CommitAsync();
 		}
+
+		await reporter.SubWork("Processing users...", 2, 4);
+
+		await using (var avatarCmd = conn.Command("SELECT id, avatar_url FROM users WHERE avatar_url IS NOT NULL")) {
+			await using var reader = await avatarCmd.ExecuteReaderAsync();
+
+			while (await reader.ReadAsync()) {
+				await InsertDownload(insertCmd, DownloadLinkExtractor.FromUserAvatar(reader.GetUint64(0), reader.GetString(1)));
+			}
+		}
+
+		await reporter.SubWork("Processing reactions...", 3, 4);
+
+		await using (var avatarCmd = conn.Command("SELECT DISTINCT emoji_id, emoji_flags FROM reactions WHERE emoji_id IS NOT NULL")) {
+			await using var reader = await avatarCmd.ExecuteReaderAsync();
+
+			while (await reader.ReadAsync()) {
+				await InsertDownload(insertCmd, DownloadLinkExtractor.FromEmoji(reader.GetUint64(0), (EmojiFlags) reader.GetInt16(1)));
+			}
+		}
+
+		await conn.CommitTransactionAsync();
 	}
 }

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

@@ -1,8 +1,15 @@
 using System;
+using System.Threading.Tasks;
 using Microsoft.Data.Sqlite;
 
 namespace DHT.Server.Database.Sqlite.Utils;
 
 interface ISqliteConnection : IAsyncDisposable {
 	SqliteConnection InnerConnection { get; }
+	
+	Task BeginTransactionAsync();
+	Task CommitTransactionAsync();
+	Task RollbackTransactionAsync();
+	
+	void AssignActiveTransaction(SqliteCommand command);
 }

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

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Data.Common;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Utils.Collections;
@@ -73,17 +74,48 @@ sealed class SqliteConnectionPool : IAsyncDisposable {
 		disposalTokenSource.Dispose();
 	}
 
-	private sealed class PooledConnection : ISqliteConnection {
+	private sealed class PooledConnection(SqliteConnectionPool pool, SqliteConnection conn) : ISqliteConnection {
-		public SqliteConnection InnerConnection { get; }
+		public SqliteConnection InnerConnection { get; } = conn;
 
-		private readonly SqliteConnectionPool pool;
+		private DbTransaction? activeTransaction;
 
-		public PooledConnection(SqliteConnectionPool pool, SqliteConnection conn) {
+		public async Task BeginTransactionAsync() {
-			this.pool = pool;
+			if (activeTransaction != null) {
-			this.InnerConnection = conn;
+				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/SqliteExtensions.cs

@@ -1,5 +1,4 @@
 using System;
-using System.Data.Common;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
@@ -9,10 +8,6 @@ using Microsoft.Data.Sqlite;
 namespace DHT.Server.Database.Sqlite.Utils;
 
 static class SqliteExtensions {
-	public static ValueTask<DbTransaction> BeginTransactionAsync(this ISqliteConnection conn) {
-		return conn.InnerConnection.BeginTransactionAsync();
-	}
-
 	public static SqliteCommand Command(this ISqliteConnection conn, [LanguageInjection("sql")] string sql) {
 		var cmd = conn.InnerConnection.CreateCommand();
 		cmd.CommandText = sql;
@@ -31,6 +26,10 @@ static class SqliteExtensions {
 		return await reader.ReadAsync(cancellationToken) ? readFunction(reader) : readFunction(null);
 	}
 	
+	public static async Task<long> ExecuteLongScalarAsync(this SqliteCommand command) {
+		return (long) (await command.ExecuteScalarAsync())!;
+	}
+
 	public static SqliteCommand Insert(this ISqliteConnection conn, string tableName, (string Name, SqliteType Type)[] columns) {
 		string columnNames = string.Join(',', columns.Select(static c => c.Name));
 		string columnParams = string.Join(',', columns.Select(static c => ':' + c.Name));

app/Server/Download/DownloadItem.cs

@@ -10,13 +10,12 @@ public readonly struct DownloadItem {
 	public string? Type { get; init; }
 	public ulong? Size { get; init; }
 	
-	internal DownloadWithData ToSuccess(byte[] data) {
+	internal Data.Download ToSuccess(long size) {
-		var size = (ulong) Math.Max(data.LongLength, 0);
+		return new Data.Download(NormalizedUrl, DownloadUrl, DownloadStatus.Success, Type, (ulong) Math.Max(size, 0));
-		return new DownloadWithData(new Data.Download(NormalizedUrl, DownloadUrl, DownloadStatus.Success, Type, size), data);
 	}
 	
-	internal DownloadWithData ToFailure(HttpStatusCode? statusCode = null) {
+	internal Data.Download ToFailure(HttpStatusCode? statusCode = null) {
 		var status = statusCode.HasValue ? (DownloadStatus) (int) statusCode : DownloadStatus.GenericError;
-		return new DownloadWithData(new Data.Download(NormalizedUrl, DownloadUrl, status, Type, Size), Data: null);
+		return new Data.Download(NormalizedUrl, DownloadUrl, status, Type, Size);
 	}
 }

app/Server/Download/Downloader.cs

@@ -11,16 +11,18 @@ public sealed class Downloader {
 	public bool IsDownloading => current != null;
 	
 	private readonly IDatabaseFile db;
+	private readonly int? concurrentDownloads;
 	private readonly SemaphoreSlim semaphore = new (1, 1);
 	
-	internal Downloader(IDatabaseFile db) {
+	internal Downloader(IDatabaseFile db, int? concurrentDownloads) {
 		this.db = db;
+		this.concurrentDownloads = concurrentDownloads;
 	}
 
 	public async Task<IObservable<DownloadItem>> Start(DownloadItemFilter filter) {
 		await semaphore.WaitAsync();
 		try {
-			current ??= new DownloaderTask(db, filter);
+			current ??= new DownloaderTask(db, filter, concurrentDownloads);
 			return current.FinishedItems;
 		} finally {
 			semaphore.Release();

app/Server/Download/DownloaderTask.cs

@@ -15,10 +15,14 @@ namespace DHT.Server.Download;
 sealed class DownloaderTask : IAsyncDisposable {
 	private static readonly Log Log = Log.ForType<DownloaderTask>();
 
-	private const int DownloadTasks = 4;
+	private const int DefaultConcurrentDownloads = 4;
 	private const int QueueSize = 25;
 	private const string UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36";
 
+	private static int GetDownloadTaskCount(int? concurrentDownloads) {
+		return Math.Max(1, concurrentDownloads ?? DefaultConcurrentDownloads);
+	}
+
 	private readonly Channel<DownloadItem> downloadQueue = Channel.CreateBounded<DownloadItem>(new BoundedChannelOptions(QueueSize) {
 		SingleReader = false,
 		SingleWriter = true,
@@ -38,12 +42,12 @@ sealed class DownloaderTask : IAsyncDisposable {
 
 	public IObservable<DownloadItem> FinishedItems => finishedItemPublisher;
 
-	internal DownloaderTask(IDatabaseFile db, DownloadItemFilter filter) {
+	internal DownloaderTask(IDatabaseFile db, DownloadItemFilter filter, int? concurrentDownloads) {
 		this.db = db;
 		this.filter = filter;
 		this.cancellationToken = cancellationTokenSource.Token;
 		this.queueWriterTask = Task.Run(RunQueueWriterTask);
-		this.downloadTasks = Enumerable.Range(1, DownloadTasks).Select(taskIndex => Task.Run(() => RunDownloadTask(taskIndex))).ToArray();
+		this.downloadTasks = Enumerable.Range(1, GetDownloadTaskCount(concurrentDownloads)).Select(taskIndex => Task.Run(() => RunDownloadTask(taskIndex))).ToArray();
 	}
 
 	private async Task RunQueueWriterTask() {
@@ -63,24 +67,39 @@ sealed class DownloaderTask : IAsyncDisposable {
 	private async Task RunDownloadTask(int taskIndex) {
 		var log = Log.ForType<DownloaderTask>("Task " + taskIndex);
 
-		var client = new HttpClient();
+		var client = new HttpClient(new SocketsHttpHandler {
+			ConnectTimeout = TimeSpan.FromSeconds(30)
+		});
+		
+		client.Timeout = Timeout.InfiniteTimeSpan;
 		client.DefaultRequestHeaders.UserAgent.ParseAdd(UserAgent);
-		client.Timeout = TimeSpan.FromSeconds(30);
 
 		while (!cancellationToken.IsCancellationRequested) {
 			var item = await downloadQueue.Reader.ReadAsync(cancellationToken);
 			log.Debug("Downloading " + item.DownloadUrl + "...");
 
 			try {
-				var downloadedBytes = await client.GetByteArrayAsync(item.DownloadUrl, cancellationToken);
+				var response = await client.SendAsync(new HttpRequestMessage(HttpMethod.Get, item.DownloadUrl), HttpCompletionOption.ResponseHeadersRead, cancellationToken);
-				await db.Downloads.AddDownload(item.ToSuccess(downloadedBytes));
+				response.EnsureSuccessStatusCode();
-			} catch (OperationCanceledException) {
+
+				if (response.Content.Headers.ContentLength is {} contentLength) {
+					await using var stream = await response.Content.ReadAsStreamAsync(cancellationToken);
+					await db.Downloads.AddDownload(item.ToSuccess(contentLength), stream);
+				}
+				else {
+					await db.Downloads.AddDownload(item.ToFailure(), stream: null);
+					log.Error("Download response has no content length: " + item.DownloadUrl);
+				}
+			} catch (OperationCanceledException e) when (e.CancellationToken == cancellationToken) {
 				// Ignore.
+			} catch (TaskCanceledException e) when (e.InnerException is TimeoutException) {
+				await db.Downloads.AddDownload(item.ToFailure(), stream: null);
+				log.Error("Download timed out: " + item.DownloadUrl);
 			} catch (HttpRequestException e) {
-				await db.Downloads.AddDownload(item.ToFailure(e.StatusCode));
+				await db.Downloads.AddDownload(item.ToFailure(e.StatusCode), stream: null);
 				log.Error(e);
 			} catch (Exception e) {
-				await db.Downloads.AddDownload(item.ToFailure());
+				await db.Downloads.AddDownload(item.ToFailure(), stream: null);
 				log.Error(e);
 			} finally {
 				try {

app/Server/Endpoints/BaseEndpoint.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Net;
 using System.Text.Json;
+using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Database;
 using DHT.Utils.Http;
@@ -9,39 +10,50 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-abstract class BaseEndpoint {
+abstract class BaseEndpoint(IDatabaseFile db) {
 	private static readonly Log Log = Log.ForType<BaseEndpoint>();
 
-	protected IDatabaseFile Db { get; }
+	protected IDatabaseFile Db { get; } = db;
-
-	protected BaseEndpoint(IDatabaseFile db) {
-		this.Db = db;
-	}
 
 	public async Task Handle(HttpContext ctx) {
 		var response = ctx.Response;
 
 		try {
 			response.StatusCode = (int) HttpStatusCode.OK;
-			var output = await Respond(ctx);
+			await Respond(ctx.Request, response, ctx.RequestAborted);
-			await output.WriteTo(response);
+		} catch (OperationCanceledException) {
+			throw;
 		} catch (HttpException e) {
 			Log.Error(e);
 			response.StatusCode = (int) e.StatusCode;
-			await response.WriteAsync(e.Message);
+			if (response.HasStarted) {
+				Log.Warn("Response has already started, cannot write status message: " + e.Message);
+			}
+			else {
+				await response.WriteAsync(e.Message);
+			}
 		} catch (Exception e) {
 			Log.Error(e);
 			response.StatusCode = (int) HttpStatusCode.InternalServerError;
 		}
 	}
 
-	protected abstract Task<IHttpOutput> Respond(HttpContext ctx);
+	protected abstract Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken);
 
-	protected static async Task<JsonElement> ReadJson(HttpContext ctx) {
+	protected static async Task<JsonElement> ReadJson(HttpRequest request) {
 		try {
-			return await ctx.Request.ReadFromJsonAsync(JsonElementContext.Default.JsonElement);
+			return await request.ReadFromJsonAsync(JsonElementContext.Default.JsonElement);
 		} catch (JsonException) {
 			throw new HttpException(HttpStatusCode.UnsupportedMediaType, "This endpoint only accepts JSON.");
 		}
 	}
+	
+	protected static Guid GetSessionId(HttpRequest request) {
+		if (request.Query.TryGetValue("session", out var sessionIdValue) && sessionIdValue.Count == 1 && Guid.TryParse(sessionIdValue[0], out Guid sessionId)) {
+			return sessionId;
+		}
+		else {
+			throw new HttpException(HttpStatusCode.BadRequest, "Invalid session ID.");
+		}
+	}
 }

app/Server/Endpoints/GetDownloadedFileEndpoint.cs

@@ -1,4 +1,7 @@
+using System;
+using System.IO;
 using System.Net;
+using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Database;
 using DHT.Server.Download;
@@ -7,18 +10,17 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class GetDownloadedFileEndpoint : BaseEndpoint {
+sealed class GetDownloadedFileEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
-	public GetDownloadedFileEndpoint(IDatabaseFile db) : base(db) {}
+	protected override async Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken) {
-
+		string url = WebUtility.UrlDecode((string) request.RouteValues["url"]!);
-	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
-		string url = WebUtility.UrlDecode((string) ctx.Request.RouteValues["url"]!);
 		string normalizedUrl = DiscordCdn.NormalizeUrl(url);
 		
-		if (await Db.Downloads.GetSuccessfulDownloadWithData(normalizedUrl) is { Download: {} download, Data: {} data }) {
+		if (!await Db.Downloads.GetSuccessfulDownloadWithData(normalizedUrl, WriteDataTo(response), cancellationToken)) {
-			return new HttpOutput.File(download.Type, data);
+			response.Redirect(url, permanent: false);
-		}
-		else {
-			return new HttpOutput.Redirect(url, permanent: false);
 		}
 	}
+	
+	private static Func<Data.Download, Stream, CancellationToken, Task> WriteDataTo(HttpResponse response) {
+		return (download, stream, cancellationToken) => response.WriteStreamAsync(download.Type, download.Size, stream, cancellationToken);
+	}
 }

app/Server/Endpoints/GetTrackingScriptEndpoint.cs

@@ -1,5 +1,5 @@
-using System.Reflection;
+using System.Net.Mime;
-using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using System.Web;
 using DHT.Server.Database;
@@ -10,25 +10,17 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class GetTrackingScriptEndpoint : BaseEndpoint {
+sealed class GetTrackingScriptEndpoint(IDatabaseFile db, ServerParameters parameters, ResourceLoader resources) : BaseEndpoint(db) {
-	private static ResourceLoader Resources { get; } = new (Assembly.GetExecutingAssembly());
+	protected override async Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken) {
+		string bootstrap = await resources.ReadTextAsync("Tracker/bootstrap.js");
+		string script = bootstrap.Replace("= 0; /*[PORT]*/", "= " + parameters.Port + ";")
+		                         .Replace("/*[TOKEN]*/", HttpUtility.JavaScriptStringEncode(parameters.Token))
+		                         .Replace("/*[IMPORTS]*/", await resources.ReadJoinedAsync("Tracker/scripts/", '\n'))
+		                         .Replace("/*[CSS-CONTROLLER]*/", await resources.ReadTextAsync("Tracker/styles/controller.css"))
+		                         .Replace("/*[CSS-SETTINGS]*/", await resources.ReadTextAsync("Tracker/styles/settings.css"))
+		                         .Replace("/*[DEBUGGER]*/", request.Query.ContainsKey("debug") ? "debugger;" : "");
 		
-	private readonly ServerParameters serverParameters;
+		response.Headers.Append("X-DHT", "1");
-	
+		await response.WriteTextAsync(MediaTypeNames.Text.JavaScript, script, cancellationToken);
-	public GetTrackingScriptEndpoint(IDatabaseFile db, ServerParameters parameters) : base(db) {
-		serverParameters = parameters;
-	}
-
-	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
-		string bootstrap = await Resources.ReadTextAsync("Tracker/bootstrap.js");
-		string script = bootstrap.Replace("= 0; /*[PORT]*/", "= " + serverParameters.Port + ";")
-		                         .Replace("/*[TOKEN]*/", HttpUtility.JavaScriptStringEncode(serverParameters.Token))
-		                         .Replace("/*[IMPORTS]*/", await Resources.ReadJoinedAsync("Tracker/scripts/", '\n'))
-		                         .Replace("/*[CSS-CONTROLLER]*/", await Resources.ReadTextAsync("Tracker/styles/controller.css"))
-		                         .Replace("/*[CSS-SETTINGS]*/", await Resources.ReadTextAsync("Tracker/styles/settings.css"))
-		                         .Replace("/*[DEBUGGER]*/", ctx.Request.Query.ContainsKey("debug") ? "debugger;" : "");
-		
-		ctx.Response.Headers.Append("X-DHT", "1");
-		return new HttpOutput.File("text/javascript", Encoding.UTF8.GetBytes(script));
 	}
 }

app/Server/Endpoints/GetViewerMessagesEndpoint.cs

@@ -0,0 +1,18 @@
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Database;
+using DHT.Server.Database.Export;
+using DHT.Server.Service.Viewer;
+using Microsoft.AspNetCore.Http;
+
+namespace DHT.Server.Endpoints; 
+
+sealed class GetViewerMessagesEndpoint(IDatabaseFile db, ViewerSessions viewerSessions) : BaseEndpoint(db) {
+	protected override Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken) {
+		var sessionId = GetSessionId(request);
+		var session = viewerSessions.Get(sessionId);
+		
+		response.ContentType = "application/x-ndjson";
+		return ViewerJsonExport.GetMessages(response.Body, Db, session.MessageFilter, cancellationToken);
+	}
+}

app/Server/Endpoints/GetViewerMetadataEndpoint.cs

@@ -0,0 +1,19 @@
+using System.Net.Mime;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Database;
+using DHT.Server.Database.Export;
+using DHT.Server.Service.Viewer;
+using Microsoft.AspNetCore.Http;
+
+namespace DHT.Server.Endpoints; 
+
+sealed class GetViewerMetadataEndpoint(IDatabaseFile db, ViewerSessions viewerSessions) : BaseEndpoint(db) {
+	protected override Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken) {
+		var sessionId = GetSessionId(request);
+		var session = viewerSessions.Get(sessionId);
+		
+		response.ContentType = MediaTypeNames.Application.Json;
+		return ViewerJsonExport.GetMetadata(response.Body, Db, session.MessageFilter, cancellationToken);
+	}
+}

app/Server/Endpoints/TrackChannelEndpoint.cs

@@ -1,5 +1,6 @@
 using System.Net;
 using System.Text.Json;
+using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Data;
 using DHT.Server.Database;
@@ -8,18 +9,14 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class TrackChannelEndpoint : BaseEndpoint {
+sealed class TrackChannelEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
-	public TrackChannelEndpoint(IDatabaseFile db) : base(db) {}
+	protected override async Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken) {
-
+		var root = await ReadJson(request);
-	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
-		var root = await ReadJson(ctx);
 		var server = ReadServer(root.RequireObject("server"), "server");
 		var channel = ReadChannel(root.RequireObject("channel"), "channel", server.Id);
 
 		await Db.Servers.Add([server]);
 		await Db.Channels.Add([channel]);
-
-		return HttpOutput.None;
 	}
 
 	private static Data.Server ReadServer(JsonElement json, string path) => new () {

app/Server/Endpoints/TrackMessagesEndpoint.cs

@@ -4,6 +4,7 @@ using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using System.Net;
 using System.Text.Json;
+using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Data;
 using DHT.Server.Data.Filters;
@@ -15,14 +16,12 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class TrackMessagesEndpoint : BaseEndpoint {
+sealed class TrackMessagesEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
 	private const string HasNewMessages = "1";
 	private const string NoNewMessages = "0";
 
-	public TrackMessagesEndpoint(IDatabaseFile db) : base(db) {}
+	protected override async Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken) {
-
+		var root = await ReadJson(request);
-	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
-		var root = await ReadJson(ctx);
 
 		if (root.ValueKind != JsonValueKind.Array) {
 			throw new HttpException(HttpStatusCode.BadRequest, "Expected root element to be an array.");
@@ -39,11 +38,11 @@ sealed class TrackMessagesEndpoint : BaseEndpoint {
 		}
 
 		var addedMessageFilter = new MessageFilter { MessageIds = addedMessageIds };
-		bool anyNewMessages = await Db.Messages.Count(addedMessageFilter) < addedMessageIds.Count;
+		bool anyNewMessages = await Db.Messages.Count(addedMessageFilter, CancellationToken.None) < addedMessageIds.Count;
 
 		await Db.Messages.Add(messages);
 
-		return new HttpOutput.Text(anyNewMessages ? HasNewMessages : NoNewMessages);
+		await response.WriteTextAsync(anyNewMessages ? HasNewMessages : NoNewMessages, cancellationToken);
 	}
 
 	private static Message ReadMessage(JsonElement json, string path) => new () {

app/Server/Endpoints/TrackUsersEndpoint.cs

@@ -1,5 +1,6 @@
 using System.Net;
 using System.Text.Json;
+using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Data;
 using DHT.Server.Database;
@@ -8,11 +9,9 @@ using Microsoft.AspNetCore.Http;
 
 namespace DHT.Server.Endpoints;
 
-sealed class TrackUsersEndpoint : BaseEndpoint {
+sealed class TrackUsersEndpoint(IDatabaseFile db) : BaseEndpoint(db) {
-	public TrackUsersEndpoint(IDatabaseFile db) : base(db) {}
+	protected override async Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken) {
-
+		var root = await ReadJson(request);
-	protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
-		var root = await ReadJson(ctx);
 
 		if (root.ValueKind != JsonValueKind.Array) {
 			throw new HttpException(HttpStatusCode.BadRequest, "Expected root element to be an array.");
@@ -26,8 +25,6 @@ sealed class TrackUsersEndpoint : BaseEndpoint {
 		}
 
 		await Db.Users.Add(users);
-
-		return HttpOutput.None;
 	}
 
 	private static User ReadUser(JsonElement json, string path) => new () {

app/Server/Endpoints/ViewerEndpoint.cs

@@ -0,0 +1,42 @@
+using System.Collections.Generic;
+using System.Net;
+using System.Threading;
+using System.Threading.Tasks;
+using DHT.Server.Database;
+using DHT.Utils.Http;
+using DHT.Utils.Resources;
+using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.StaticFiles;
+
+namespace DHT.Server.Endpoints;
+
+sealed class ViewerEndpoint(IDatabaseFile db, ResourceLoader resources) : BaseEndpoint(db) {
+	private static readonly FileExtensionContentTypeProvider ContentTypeProvider = new ();
+
+	private readonly Dictionary<string, byte[]?> cache = new ();
+	private readonly SemaphoreSlim cacheSemaphore = new (1);
+
+	protected override async Task Respond(HttpRequest request, HttpResponse response, CancellationToken cancellationToken) {
+		string path = (string?) request.RouteValues["path"] ?? "index.html";
+		string resourcePath = "Viewer/" + path;
+		
+		byte[]? resourceBytes;
+
+		await cacheSemaphore.WaitAsync(cancellationToken);
+		try {
+			if (!cache.TryGetValue(resourcePath, out resourceBytes)) {
+				cache[resourcePath] = resourceBytes = await resources.ReadBytesAsyncIfExists(resourcePath);
+			}
+		} finally {
+			cacheSemaphore.Release();
+		}
+
+		if (resourceBytes == null) {
+			throw new HttpException(HttpStatusCode.NotFound, "File not found: " + path);
+		}
+		else {
+			var contentType = ContentTypeProvider.TryGetContentType(path, out string? type) ? type : null;
+			await response.WriteFileAsync(contentType, resourceBytes, cancellationToken);
+		}
+	}
+}

app/Server/Server.csproj

@@ -39,6 +39,16 @@
       <Link>Resources/Tracker/styles/%(RecursiveDir)%(Filename)%(Extension)</Link>
       <Visible>false</Visible>
     </EmbeddedResource>
+    <EmbeddedResource Include="../Resources/Viewer/**">
+      <LogicalName>Viewer\%(RecursiveDir)%(Filename)%(Extension)</LogicalName>
+      <Link>Resources/Viewer/%(RecursiveDir)%(Filename)%(Extension)</Link>
+      <Visible>false</Visible>
+    </EmbeddedResource>
+    <EmbeddedResource Include="../Desktop/Resources/icon.ico">
+      <LogicalName>Viewer\favicon.ico</LogicalName>
+      <Link>Resources/icon.ico</Link>
+      <Visible>false</Visible>
+    </EmbeddedResource>
   </ItemGroup>
   
 </Project>

app/Server/Service/Middlewares/ServerLoggingMiddleware.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Diagnostics;
 using System.Threading.Tasks;
 using DHT.Utils.Logging;
@@ -6,24 +7,34 @@ using Microsoft.AspNetCore.Http.Extensions;
 
 namespace DHT.Server.Service.Middlewares;
 
-sealed class ServerLoggingMiddleware {
+sealed class ServerLoggingMiddleware(RequestDelegate next) {
 	private static readonly Log Log = Log.ForType<ServerLoggingMiddleware>();
 
-	private readonly RequestDelegate next;
-	
-	public ServerLoggingMiddleware(RequestDelegate next) {
-		this.next = next;
-	}
-
 	public async Task InvokeAsync(HttpContext context) {
 		var stopwatch = Stopwatch.StartNew();
-		await next(context);
+		try {
+			await next(context);
+		} catch (OperationCanceledException) {
+			OnFinished(stopwatch, context);
+			throw;
+		}
+
+		OnFinished(stopwatch, context);
+	}
+
+	private static void OnFinished(Stopwatch stopwatch, HttpContext context) {
 		stopwatch.Stop();
 
 		var request = context.Request;
 		var requestLength = request.ContentLength ?? 0L;
-		var responseStatus = context.Response.StatusCode;
 		var elapsedMs = stopwatch.ElapsedMilliseconds;
-		Log.Debug("Request to " + request.GetEncodedPathAndQuery() + " (" + requestLength + " B) returned " + responseStatus + ", took " + elapsedMs + " ms");
+
+		if (context.RequestAborted.IsCancellationRequested) {
+			Log.Debug("Request to " + request.GetEncodedPathAndQuery() + " (" + requestLength + " B) was cancelled after " + elapsedMs + " ms");
+		}
+		else {
+			var responseStatus = context.Response.StatusCode;
+			Log.Debug("Request to " + request.GetEncodedPathAndQuery() + " (" + requestLength + " B) returned " + responseStatus + ", took " + elapsedMs + " ms");
+		}
 	}
 }

app/Server/Service/ServerManager.cs

@@ -1,8 +1,11 @@
 using System;
+using System.Reflection;
 using System.Threading;
 using System.Threading.Tasks;
 using DHT.Server.Database;
+using DHT.Server.Service.Viewer;
 using DHT.Utils.Logging;
+using DHT.Utils.Resources;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.AspNetCore.Server.Kestrel.Core;
 using Microsoft.Extensions.DependencyInjection;
@@ -25,10 +28,12 @@ public sealed class ServerManager {
 	}
 
 	private readonly IDatabaseFile db;
+	private readonly ViewerSessions viewerSessions;
 	private readonly SemaphoreSlim semaphore = new (1, 1);
 
-	internal ServerManager(IDatabaseFile db) {
+	internal ServerManager(IDatabaseFile db, ViewerSessions viewerSessions) {
 		this.db = db;
+		this.viewerSessions = viewerSessions;
 	}
 
 	public async Task Start(ushort port, string token) {
@@ -57,6 +62,8 @@ public sealed class ServerManager {
 		void AddServices(IServiceCollection services) {
 			services.AddSingleton(typeof(IDatabaseFile), db);
 			services.AddSingleton(typeof(ServerParameters), new ServerParameters(port, token));
+			services.AddSingleton(typeof(ResourceLoader), new ResourceLoader(Assembly.GetExecutingAssembly()));
+			services.AddSingleton(typeof(ViewerSessions), viewerSessions);
 		}
 
 		void SetKestrelOptions(KestrelServerOptions options) {

app/Server/Service/ServerStartup.cs

@@ -3,6 +3,8 @@ using System.Text.Json.Serialization;
 using DHT.Server.Database;
 using DHT.Server.Endpoints;
 using DHT.Server.Service.Middlewares;
+using DHT.Server.Service.Viewer;
+using DHT.Utils.Resources;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Http.Json;
 using Microsoft.Extensions.DependencyInjection;
@@ -33,14 +35,24 @@ sealed class Startup {
 	}
 
 	[SuppressMessage("ReSharper", "UnusedMember.Global")]
-	public void Configure(IApplicationBuilder app, IHostApplicationLifetime lifetime, IDatabaseFile db, ServerParameters parameters) {
+	public void Configure(IApplicationBuilder app, IHostApplicationLifetime lifetime, IDatabaseFile db, ServerParameters parameters, ResourceLoader resources, ViewerSessions viewerSessions) {
 		app.UseMiddleware<ServerLoggingMiddleware>();
 		app.UseCors();
-		app.UseMiddleware<ServerAuthorizationMiddleware>();
-		app.UseRouting();
 		
+		app.Map("/viewer", node => {
+			node.UseRouting();
+			node.UseEndpoints(endpoints => {
+				endpoints.MapGet("/{**path}", new ViewerEndpoint(db, resources).Handle);
+			});
+		});
+		
+		app.UseMiddleware<ServerAuthorizationMiddleware>();
+		
+		app.UseRouting();
 		app.UseEndpoints(endpoints => {
-			endpoints.MapGet("/get-tracking-script", new GetTrackingScriptEndpoint(db, parameters).Handle);
+			endpoints.MapGet("/get-tracking-script", new GetTrackingScriptEndpoint(db, parameters, resources).Handle);
+			endpoints.MapGet("/get-viewer-metadata", new GetViewerMetadataEndpoint(db, viewerSessions).Handle);
+			endpoints.MapGet("/get-viewer-messages", new GetViewerMessagesEndpoint(db, viewerSessions).Handle);
 			endpoints.MapGet("/get-downloaded-file/{url}", new GetDownloadedFileEndpoint(db).Handle);
 			endpoints.MapPost("/track-channel", new TrackChannelEndpoint(db).Handle);
 			endpoints.MapPost("/track-users", new TrackUsersEndpoint(db).Handle);

app/Server/Service/Viewer/ViewerSession.cs

@@ -0,0 +1,5 @@
+using DHT.Server.Data.Filters;
+
+namespace DHT.Server.Service.Viewer; 
+
+public readonly record struct ViewerSession(MessageFilter? MessageFilter);

app/Server/Service/Viewer/ViewerSessions.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+
+namespace DHT.Server.Service.Viewer;
+
+public sealed class ViewerSessions : IDisposable {
+	private readonly Dictionary<Guid, ViewerSession> sessions = new ();
+	private bool isDisposed = false;
+
+	public Guid Register(ViewerSession session) {
+		Guid guid = Guid.NewGuid();
+		
+		lock (this) {
+			ObjectDisposedException.ThrowIf(isDisposed, this);
+			sessions[guid] = session;
+		}
+		
+		return guid;
+	}
+
+	internal ViewerSession Get(Guid guid) {
+		lock (this) {
+			return sessions.GetValueOrDefault(guid);
+		}
+	}
+
+	public void Dispose() {
+		lock (this) {
+			if (!isDisposed) {
+				isDisposed = true;
+				sessions.Clear();
+			}
+		}
+	}
+}

app/Server/State.cs

@@ -3,25 +3,29 @@ using System.Threading.Tasks;
 using DHT.Server.Database;
 using DHT.Server.Download;
 using DHT.Server.Service;
+using DHT.Server.Service.Viewer;
 
 namespace DHT.Server;
 
 public sealed class State : IAsyncDisposable {
-	public static State Dummy { get; } = new (DummyDatabaseFile.Instance);
+	public static State Dummy { get; } = new (DummyDatabaseFile.Instance, null);
 
 	public IDatabaseFile Db { get; }
 	public Downloader Downloader { get; }
+	public ViewerSessions ViewerSessions { get; }
 	public ServerManager Server { get; }
 
-	public State(IDatabaseFile db) {
+	public State(IDatabaseFile db, int? concurrentDownloads) {
 		Db = db;
-		Downloader = new Downloader(db);
+		Downloader = new Downloader(db, concurrentDownloads);
-		Server = new ServerManager(db);
+		ViewerSessions = new ViewerSessions();
+		Server = new ServerManager(db, ViewerSessions);
 	}
 
 	public async ValueTask DisposeAsync() {
 		await Downloader.Stop();
 		await Server.Stop();
 		await Db.DisposeAsync();
+		ViewerSessions.Dispose();
 	}
 }

app/Utils/Collections/LinqExtensions.cs

@@ -8,7 +8,7 @@ public static class LinqExtensions {
 		HashSet<TKey>? seenKeys = null;
 
 		foreach (var item in collection) {
-			seenKeys ??= new HashSet<TKey>();
+			seenKeys ??= [];
 
 			if (seenKeys.Add(getKeyFromItem(item))) {
 				yield return item;

app/Utils/Http/HttpExtensions.cs

@@ -0,0 +1,34 @@
+using System.IO;
+using System.Net.Mime;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Http;
+
+namespace DHT.Utils.Http; 
+
+public static class HttpExtensions {
+	public static Task WriteTextAsync(this HttpResponse response, string text, CancellationToken cancellationToken) {
+		return WriteTextAsync(response, MediaTypeNames.Text.Plain, text, cancellationToken);
+	}
+	
+	public static async Task WriteTextAsync(this HttpResponse response, string contentType, string text, CancellationToken cancellationToken) {
+		response.ContentType = contentType;
+		await response.StartAsync(cancellationToken);
+		await response.WriteAsync(text, Encoding.UTF8, cancellationToken);
+	}
+	
+	public static async Task WriteFileAsync(this HttpResponse response, string? contentType, byte[] bytes, CancellationToken cancellationToken) {
+		response.ContentType = contentType ?? string.Empty;
+		response.ContentLength = bytes.Length;
+		await response.StartAsync(cancellationToken);
+		await response.Body.WriteAsync(bytes, cancellationToken);
+	}
+	
+	public static async Task WriteStreamAsync(this HttpResponse response, string? contentType, ulong? contentLength, Stream source, CancellationToken cancellationToken) {
+		response.ContentType = contentType ?? string.Empty;
+		response.ContentLength = (long?) contentLength;
+		await response.StartAsync(cancellationToken);
+		await source.CopyToAsync(response.Body, cancellationToken);
+	}
+}

app/Utils/Http/HttpOutput.cs

@@ -1,35 +0,0 @@
-using System.Text;
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
-
-namespace DHT.Utils.Http;
-
-public static class HttpOutput {
-	public static IHttpOutput None { get; } = new NoneImpl();
-
-	private sealed class NoneImpl : IHttpOutput {
-		public Task WriteTo(HttpResponse response) {
-			return Task.CompletedTask;
-		}
-	}
-
-	public sealed class Text(string text) : IHttpOutput {
-		public Task WriteTo(HttpResponse response) {
-			return response.WriteAsync(text, Encoding.UTF8);
-		}
-	}
-
-	public sealed class File(string? contentType, byte[] bytes) : IHttpOutput {
-		public async Task WriteTo(HttpResponse response) {
-			response.ContentType = contentType ?? string.Empty;
-			await response.Body.WriteAsync(bytes);
-		}
-	}
-
-	public sealed class Redirect(string url, bool permanent) : IHttpOutput {
-		public Task WriteTo(HttpResponse response) {
-			response.Redirect(url, permanent);
-			return Task.CompletedTask;
-		}
-	}
-}

app/Utils/Http/IHttpOutput.cs

@@ -1,8 +0,0 @@
-using System.Threading.Tasks;
-using Microsoft.AspNetCore.Http;
-
-namespace DHT.Utils.Http;
-
-public interface IHttpOutput {
-	Task WriteTo(HttpResponse response);
-}

app/Utils/Resources/ResourceLoader.cs

@@ -7,8 +7,9 @@ using System.Threading.Tasks;
 namespace DHT.Utils.Resources;
 
 public sealed class ResourceLoader(Assembly assembly) {
-	private Stream GetEmbeddedStream(string filename) {
+	private Stream? TryGetEmbeddedStream(string filename) {
 		Stream? stream = null;
+		
 		foreach (var embeddedName in assembly.GetManifestResourceNames()) {
 			if (embeddedName.Replace('\\', '/') == filename) {
 				stream = assembly.GetManifestResourceStream(embeddedName);
@@ -16,7 +17,11 @@ public sealed class ResourceLoader(Assembly assembly) {
 			}
 		}
 
-		return stream ?? throw new ArgumentException("Missing embedded resource: " + filename);
+		return stream;
+	}
+	
+	private Stream GetEmbeddedStream(string filename) {
+		return TryGetEmbeddedStream(filename) ?? throw new ArgumentException("Missing embedded resource: " + filename);
 	}
 
 	private async Task<string> ReadTextAsync(Stream stream) {
@@ -24,10 +29,20 @@ public sealed class ResourceLoader(Assembly assembly) {
 		return await reader.ReadToEndAsync();
 	}
 	
+	private async Task<byte[]> ReadBytesAsync(Stream stream) {
+		using var memoryStream = new MemoryStream();
+		await stream.CopyToAsync(memoryStream);
+		return memoryStream.ToArray();
+	}
+
 	public async Task<string> ReadTextAsync(string filename) {
 		return await ReadTextAsync(GetEmbeddedStream(filename));
 	}
 	
+	public async Task<byte[]?> ReadBytesAsyncIfExists(string filename) {
+		return TryGetEmbeddedStream(filename) is {} stream ? await ReadBytesAsync(stream) : null;
+	}
+
 	public async Task<string> ReadJoinedAsync(string path, char separator) {
 		StringBuilder joined = new ();
 

app/Version.cs

@@ -8,5 +8,5 @@ using DHT.Utils;
 namespace DHT.Utils;
 
 static class Version {
-	public const string Tag = "41.1.0.0";
+	public const string Tag = "41.2.0.0";
 }