Release v37.1

Closes #189

app/Desktop/App.axaml

@@ -33,9 +33,6 @@
         <Style Selector="TextBox:focus /template/ Border#PART_BorderElement">
             <Setter Property="BorderThickness" Value="1" />
         </Style>
-        <Style Selector="TextBox:disabled"><!-- TODO bug in Avalonia (https://github.com/AvaloniaUI/Avalonia/pull/7792) -->
-            <Setter Property="Foreground" Value="{DynamicResource TextControlForegroundDisabled}" />
-        </Style>
         <Style Selector="TextBox:error DataValidationErrors">
             <Style.Resources>
                 <ControlTemplate x:Key="InlineDataValidationContentTemplate" TargetType="DataValidationErrors">

app/Desktop/Common/BytesValueConverter.cs

@@ -4,12 +4,26 @@ using Avalonia.Data.Converters;
 
 namespace DHT.Desktop.Common {
 	sealed class BytesValueConverter : IValueConverter {
-		private static readonly string[] Units = {
-			"B",
-			"kB",
-			"MB",
-			"GB",
-			"TB"
+		private sealed class Unit {
+			private readonly string label;
+			private readonly string numberFormat;
+			
+			public Unit(string label, int decimalPlaces) {
+				this.label = label;
+				this.numberFormat = "{0:n" + decimalPlaces + "}";
+			}
+			
+			public string Format(double size) {
+				return string.Format(Program.Culture, numberFormat, size) + " " + label;
+			}
+		}
+		
+		private static readonly Unit[] Units = {
+			new ("B", decimalPlaces: 0),
+			new ("kB", decimalPlaces: 0),
+			new ("MB", decimalPlaces: 1),
+			new ("GB", decimalPlaces: 1),
+			new ("TB", decimalPlaces: 1)
 		};
 
 		private const int Scale = 1000;
@@ -17,13 +31,7 @@ namespace DHT.Desktop.Common {
 		private static string Convert(ulong size) {
 			int power = size == 0L ? 0 : (int) Math.Log(size, Scale);
 			int unit = power >= Units.Length ? Units.Length - 1 : power;
-			if (unit == 0) {
-				return string.Format(Program.Culture, "{0:n0}", size) + " " + Units[unit];
-			}
-			else {
-				double humanReadableSize = size / Math.Pow(Scale, unit);
-				return string.Format(Program.Culture, "{0:n0}", humanReadableSize) + " " + Units[unit];
-			}
+			return Units[unit].Format(unit == 0 ? size : size / Math.Pow(Scale, unit));
 		}
 
 		public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture) {

app/Desktop/Desktop.csproj

@@ -21,10 +21,10 @@
     <DebugType>none</DebugType>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="Avalonia" Version="0.10.14" />
-    <PackageReference Include="Avalonia.Controls.DataGrid" Version="0.10.14" />
-    <PackageReference Include="Avalonia.Desktop" Version="0.10.14" />
-    <PackageReference Include="Avalonia.Diagnostics" Version="0.10.14" Condition=" '$(Configuration)' == 'Debug' " />
+    <PackageReference Include="Avalonia" Version="0.10.16" />
+    <PackageReference Include="Avalonia.Controls.DataGrid" Version="0.10.16" />
+    <PackageReference Include="Avalonia.Desktop" Version="0.10.16" />
+    <PackageReference Include="Avalonia.Diagnostics" Version="0.10.16" Condition=" '$(Configuration)' == 'Debug' " />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Server\Server.csproj" />

app/Desktop/Main/Pages/ViewerPageModel.cs

@@ -11,9 +11,11 @@ using Avalonia.Controls;
 using DHT.Desktop.Common;
 using DHT.Desktop.Dialogs.Message;
 using DHT.Desktop.Main.Controls;
+using DHT.Desktop.Server;
 using DHT.Server.Data.Filters;
 using DHT.Server.Database;
 using DHT.Server.Database.Export;
+using DHT.Server.Database.Export.Strategy;
 using DHT.Utils.Models;
 using static DHT.Desktop.Program;
 
@@ -55,7 +57,7 @@ namespace DHT.Desktop.Main.Pages {
 			HasFilters = FilterModel.HasAnyFilters;
 		}
 
-		private async Task WriteViewerFile(string path) {
+		private async Task WriteViewerFile(string path, IViewerExportStrategy strategy) {
 			const string ArchiveTag = "/*[ARCHIVE]*/";
 
 			string indexFile = await Resources.ReadTextAsync("Viewer/index.html");
@@ -68,7 +70,7 @@ namespace DHT.Desktop.Main.Pages {
 			string jsonTempFile = path + ".tmp";
 
 			await using (var jsonStream = new FileStream(jsonTempFile, FileMode.Create, FileAccess.ReadWrite, FileShare.Read)) {
-				await ViewerJsonExport.Generate(jsonStream, db, FilterModel.CreateFilter());
+				await ViewerJsonExport.Generate(jsonStream, strategy, db, FilterModel.CreateFilter());
 
 				char[] jsonBuffer = new char[Math.Min(32768, jsonStream.Position)];
 				jsonStream.Position = 0;
@@ -106,7 +108,7 @@ namespace DHT.Desktop.Main.Pages {
 			TemporaryFiles.Add(fullPath);
 			
 			Directory.CreateDirectory(rootPath);
-			await WriteViewerFile(fullPath);
+			await WriteViewerFile(fullPath, new LiveViewerExportStrategy(ServerManager.Port, ServerManager.Token));
 
 			Process.Start(new ProcessStartInfo(fullPath) { UseShellExecute = true });
 		}
@@ -126,7 +128,7 @@ namespace DHT.Desktop.Main.Pages {
 
 			string? path = await dialog;
 			if (!string.IsNullOrEmpty(path)) {
-				await WriteViewerFile(path);
+				await WriteViewerFile(path, StandaloneViewerExportStrategy.Instance);
 			}
 		}
 

app/Resources/Tracker/scripts/discord.js

@@ -91,11 +91,13 @@ class DISCORD {
 	static getMessageElementProps(ele) {
 		const props = DOM.getReactProps(ele);
 		
-		if (props.children && props.children.length >= 4) {
-			const childProps = props.children[3].props;
-			
-			if ("message" in childProps && "channel" in childProps) {
-				return childProps;
+		if (props.children && props.children.length) {
+			for (let i = 3; i < props.children.length; i++) {
+				const childProps = props.children[i].props;
+				
+				if (childProps && "message" in childProps && "channel" in childProps) {
+					return childProps;
+				}
 			}
 		}
 		

app/Resources/Tracker/scripts/state.js

@@ -251,6 +251,11 @@ const STATE = (function() {
 							mapped.type = attachment.content_type;
 						}
 						
+						if (attachment.width && attachment.height) {
+							mapped.width = attachment.width;
+							mapped.height = attachment.height;
+						}
+						
 						return mapped;
 					});
 				}

app/Resources/Tracker/styles/controller.css

@@ -1,9 +1,5 @@
-#app-mount div[class*="app-"] {
-  margin-bottom: 48px !important;
-}
-
-#app-mount div[class*="app-"] > div[class*="app-"] {
-  margin-bottom: 0 !important;
+#app-mount {
+  height: calc(100% - 48px) !important;
 }
 
 #dht-ctrl {

app/Resources/Viewer/scripts/discord.js

@@ -78,6 +78,12 @@ const DISCORD = (function() {
 		}
 	};
 	
+	const isImageUrl = function(url) {
+		const dot = url.pathname.lastIndexOf(".");
+		const ext = dot === -1 ? "" : url.pathname.substring(dot).toLowerCase();
+		return ext === ".png" || ext === ".gif" || ext === ".jpg" || ext === ".jpeg";
+	};
+	
 	return {
 		setup() {
 			templateChannelServer = new TEMPLATE([
@@ -123,7 +129,7 @@ const DISCORD = (function() {
 			
 			// noinspection HtmlUnknownTarget
 			templateAttachmentDownload = new TEMPLATE([
-				"<a href='{url}' class='embed download'>Download {filename}</a>"
+				"<a href='{url}' class='embed download'>Download {name}</a>"
 			].join(""));
 			
 			// noinspection HtmlUnknownTarget
@@ -176,9 +182,8 @@ const DISCORD = (function() {
 		},
 		
 		isImageAttachment(attachment) {
-			const dot = attachment.url.lastIndexOf(".");
-			const ext = dot === -1 ? "" : attachment.url.substring(dot).toLowerCase();
-			return ext === ".png" || ext === ".gif" || ext === ".jpg" || ext === ".jpeg";
+			const url = DOM.tryParseUrl(attachment.url);
+			return url != null && isImageUrl(url);
 		},
 		
 		getChannelHTML(channel) { // noinspection FunctionWithInconsistentReturnsJS
@@ -235,16 +240,14 @@ const DISCORD = (function() {
 					}
 					
 					return value.map(attachment => {
-						if (this.isImageAttachment(attachment) && SETTINGS.enableImagePreviews) {
-							return templateEmbedImage.apply({ url: attachment.url, src: attachment.url });
+						if (!DISCORD.isImageAttachment(attachment) || !SETTINGS.enableImagePreviews) {
+							return templateAttachmentDownload.apply(attachment);
+						}
+						else if ("width" in attachment && "height" in attachment) {
+							return templateEmbedImageWithSize.apply({ url: attachment.url, src: attachment.url, width: attachment.width, height: attachment.height });
 						}
 						else {
-							const sliced = attachment.url.split("/");
-							
-							return templateAttachmentDownload.apply({
-								"url": attachment.url,
-								"filename": sliced[sliced.length - 1]
-							});
+							return templateEmbedImage.apply({ url: attachment.url, src: attachment.url });
 						}
 					}).join("");
 				}

app/Resources/Viewer/scripts/dom.js

@@ -51,4 +51,15 @@ class DOM {
 		const date = new Date(timestamp);
 		return date.toLocaleDateString() + ", " + date.toLocaleTimeString();
 	};
+	
+	/**
+	 * Parses a url string into a URL object and returns it. If the parsing fails, returns null.
+	 */
+	static tryParseUrl(url) {
+		try {
+			return new URL(url);
+		} catch (ignore) {
+			return null;
+		}
+	}
 }

app/Server/Data/Attachment.cs

@@ -5,5 +5,7 @@ namespace DHT.Server.Data {
 		public string? Type { get; internal init; }
 		public string Url { get; internal init; }
 		public ulong Size { get; internal init; }
+		public int? Width { get; internal init; }
+		public int? Height { get; internal init; }
 	}
 }

app/Server/Data/DownloadedAttachment.cs

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

app/Server/Database/DummyDatabaseFile.cs

@@ -63,6 +63,10 @@ namespace DHT.Server.Database {
 			return download;
 		}
 
+		public DownloadedAttachment? GetDownloadedAttachment(string url) {
+			return null;
+		}
+
 		public void AddDownload(Data.Download download) {}
 
 		public void EnqueueDownloadItems(AttachmentFilter? filter = null) {}

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

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

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

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

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

@@ -0,0 +1,13 @@
+using DHT.Server.Data;
+
+namespace DHT.Server.Database.Export.Strategy {
+	public sealed class StandaloneViewerExportStrategy : IViewerExportStrategy {
+		public static StandaloneViewerExportStrategy Instance { get; } = new ();
+
+		private StandaloneViewerExportStrategy() {}
+
+		public string GetAttachmentUrl(Attachment attachment) {
+			return attachment.Url;
+		}
+	}
+}

app/Server/Database/Export/ViewerJsonExport.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
@@ -5,13 +6,14 @@ using System.Text.Json;
 using System.Threading.Tasks;
 using DHT.Server.Data;
 using DHT.Server.Data.Filters;
+using DHT.Server.Database.Export.Strategy;
 using DHT.Utils.Logging;
 
 namespace DHT.Server.Database.Export {
 	public 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 Generate(Stream stream, IViewerExportStrategy strategy, IDatabaseFile db, MessageFilter? filter = null) {
 			var perf = Log.Start();
 
 			var includedUserIds = new HashSet<ulong>();
@@ -41,7 +43,7 @@ namespace DHT.Server.Database.Export {
 
 			var value = new {
 				meta = new { users, userindex, servers, channels },
-				data = GenerateMessageList(includedMessages, userIndices)
+				data = GenerateMessageList(includedMessages, userIndices, strategy)
 			};
 			
 			perf.Step("Generate value object");
@@ -138,7 +140,7 @@ namespace DHT.Server.Database.Export {
 			return channels;
 		}
 
-		private static object GenerateMessageList(List<Message> includedMessages, Dictionary<ulong, object> userIndices) {
+		private static object GenerateMessageList( List<Message> includedMessages, Dictionary<ulong, object> userIndices, IViewerExportStrategy strategy) {
 			var data = new Dictionary<string, Dictionary<string, object>>();
 
 			foreach (var grouping in includedMessages.GroupBy(static message => message.Channel)) {
@@ -164,8 +166,18 @@ namespace DHT.Server.Database.Export {
 					}
 
 					if (!message.Attachments.IsEmpty) {
-						obj["a"] = message.Attachments.Select(static attachment => new Dictionary<string, object> {
-							{ "url", attachment.Url }
+						obj["a"] = message.Attachments.Select(attachment => {
+							var a = new Dictionary<string, object> {
+								{ "url", strategy.GetAttachmentUrl(attachment) },
+								{ "name", Uri.TryCreate(attachment.Url, UriKind.Absolute, out var uri) ? Path.GetFileName(uri.LocalPath) : attachment.Url }
+							};
+
+							if (attachment.Width != null && attachment.Height != null) {
+								a["width"] = attachment.Width;
+								a["height"] = attachment.Height;
+							}
+							
+							return a;
 						}).ToArray();
 					}
 
@@ -188,7 +200,7 @@ namespace DHT.Server.Database.Export {
 							r["a"] = reaction.EmojiFlags.HasFlag(EmojiFlags.Animated);
 							r["c"] = reaction.Count;
 							return r;
-						});
+						}).ToArray();
 					}
 
 					channelData[message.Id.ToString()] = obj;

app/Server/Database/IDatabaseFile.cs

@@ -31,7 +31,8 @@ namespace DHT.Server.Database {
 		void AddDownload(Data.Download download);
 		List<Data.Download> GetDownloadsWithoutData();
 		Data.Download GetDownloadWithData(Data.Download download);
-		
+		DownloadedAttachment? GetDownloadedAttachment(string url);
+
 		void EnqueueDownloadItems(AttachmentFilter? filter = null);
 		List<DownloadItem> GetEnqueuedDownloadItems(int count);
 		void RemoveDownloadItems(DownloadItemFilter? filter, FilterRemovalMode mode);

app/Server/Database/Sqlite/Schema.cs

@@ -6,7 +6,7 @@ using DHT.Utils.Logging;
 
 namespace DHT.Server.Database.Sqlite {
 	sealed class Schema {
-		internal const int Version = 4;
+		internal const int Version = 5;
 
 		private static readonly Log Log = Log.ForType<Schema>();
 
@@ -79,7 +79,9 @@ namespace DHT.Server.Database.Sqlite {
 			        name TEXT NOT NULL,
 			        type TEXT,
 			        url TEXT NOT NULL,
-			        size INTEGER NOT NULL)");
+			        size INTEGER NOT NULL,
+			        width INTEGER,
+			        height INTEGER)");
 
 			Execute(@"CREATE TABLE embeds (
 			        message_id INTEGER NOT NULL,
@@ -159,6 +161,12 @@ namespace DHT.Server.Database.Sqlite {
 				perf.Step("Upgrade to version 4");
 			}
 
+			if (dbVersion <= 4) {
+				Execute("ALTER TABLE attachments ADD width INTEGER");
+				Execute("ALTER TABLE attachments ADD height INTEGER");
+				perf.Step("Upgrade to version 5");
+			}
+
 			perf.End();
 		}
 	}

app/Server/Database/Sqlite/SqliteDatabaseFile.cs

@@ -252,7 +252,9 @@ namespace DHT.Server.Database.Sqlite {
 					("name", SqliteType.Text),
 					("type", SqliteType.Text),
 					("url", SqliteType.Text),
-					("size", SqliteType.Integer)
+					("size", SqliteType.Integer),
+					("width", SqliteType.Integer),
+					("height", SqliteType.Integer)
 				});
 
 				using var embedCmd = conn.Insert("embeds", new[] {
@@ -307,6 +309,8 @@ namespace DHT.Server.Database.Sqlite {
 							attachmentCmd.Set(":type", attachment.Type);
 							attachmentCmd.Set(":url", attachment.Url);
 							attachmentCmd.Set(":size", attachment.Size);
+							attachmentCmd.Set(":width", attachment.Width);
+							attachmentCmd.Set(":height", attachment.Height);
 							attachmentCmd.ExecuteNonQuery();
 						}
 					}
@@ -470,6 +474,28 @@ LEFT JOIN replied_to rt ON m.message_id = rt.message_id" + filter.GenerateWhereC
 			}
 		}
 
+		public DownloadedAttachment? GetDownloadedAttachment(string url) {
+			using var conn = pool.Take();
+			using var cmd = conn.Command(@"
+SELECT a.type, d.blob FROM downloads d
+LEFT JOIN attachments a ON d.url = a.url
+WHERE d.url = :url AND d.status = :success AND d.blob IS NOT NULL");
+			
+			cmd.AddAndSet(":url", SqliteType.Text, url);
+			cmd.AddAndSet(":success", SqliteType.Integer, (int) DownloadStatus.Success);
+			
+			using var reader = cmd.ExecuteReader();
+
+			if (!reader.Read()) {
+				return null;
+			}
+			
+			return new DownloadedAttachment {
+				Type = reader.IsDBNull(0) ? null : reader.GetString(0),
+				Data = (byte[]) reader["blob"]
+			};
+		}
+
 		public void EnqueueDownloadItems(AttachmentFilter? filter = null) {
 			using var conn = pool.Take();
 			using var cmd = conn.Command("INSERT INTO downloads (url, status, size) SELECT a.url, :enqueued, MAX(a.size) FROM attachments a" + filter.GenerateWhereClause("a") + " GROUP BY a.url");
@@ -549,7 +575,7 @@ FROM downloads");
 			var dict = new MultiDictionary<ulong, Attachment>();
 
 			using var conn = pool.Take();
-			using var cmd = conn.Command("SELECT message_id, attachment_id, name, type, url, size FROM attachments");
+			using var cmd = conn.Command("SELECT message_id, attachment_id, name, type, url, size, width, height FROM attachments");
 			using var reader = cmd.ExecuteReader();
 
 			while (reader.Read()) {
@@ -560,7 +586,9 @@ FROM downloads");
 					Name = reader.GetString(2),
 					Type = reader.IsDBNull(3) ? null : reader.GetString(3),
 					Url = reader.GetString(4),
-					Size = reader.GetUint64(5)
+					Size = reader.GetUint64(5),
+					Width = reader.IsDBNull(6) ? null : reader.GetInt32(6),
+					Height = reader.IsDBNull(7) ? null : reader.GetInt32(7)
 				});
 			}
 

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

@@ -45,22 +45,21 @@ namespace DHT.Server.Database.Sqlite.Utils {
 		}
 
 		public ISqliteConnection Take() {
-			PooledConnection? conn = null;
-			
-			while (conn == null) {
+			while (true) {
 				ThrowIfDisposed();
+				
 				lock (monitor) {
-					if (free.TryTake(out conn, TimeSpan.FromMilliseconds(rand.Next(100, 200)))) {
+					if (free.TryTake(out var conn)) {
 						used.Add(conn);
-						break;
+						return conn;
 					}
 					else {
 						Log.ForType<SqliteConnectionPool>().Warn("Thread " + Thread.CurrentThread.ManagedThreadId + " is starving for connections.");
 					}
 				}
+				
+				Thread.Sleep(TimeSpan.FromMilliseconds(rand.Next(100, 200)));
 			}
-
-			return conn;
 		}
 
 		private void Return(PooledConnection conn) {

app/Server/Endpoints/BaseEndpoint.cs

@@ -8,6 +8,7 @@ using DHT.Utils.Http;
 using DHT.Utils.Logging;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Extensions;
+using Microsoft.Extensions.Primitives;
 
 namespace DHT.Server.Endpoints {
 	abstract class BaseEndpoint {
@@ -21,26 +22,22 @@ namespace DHT.Server.Endpoints {
 			this.parameters = parameters;
 		}
 
-		public async Task Handle(HttpContext ctx) {
+		private async Task Handle(HttpContext ctx, StringValues token) {
 			var request = ctx.Request;
 			var response = ctx.Response;
 
 			Log.Info("Request: " + request.GetDisplayUrl() + " (" + request.ContentLength + " B)");
-
-			var requestToken = request.Headers["X-DHT-Token"];
-			if (requestToken.Count != 1 || requestToken[0] != parameters.Token) {
-				Log.Error("Token: " + (requestToken.Count == 1 ? requestToken[0] : "<missing>"));
+			
+			if (token.Count != 1 || token[0] != parameters.Token) {
+				Log.Error("Token: " + (token.Count == 1 ? token[0] : "<missing>"));
 				response.StatusCode = (int) HttpStatusCode.Forbidden;
 				return;
 			}
 
 			try {
-				var (statusCode, output) = await Respond(ctx);
-				response.StatusCode = (int) statusCode;
-
-				if (output != null) {
-					await response.WriteAsJsonAsync(output);
-				}
+				response.StatusCode = (int) HttpStatusCode.OK;
+				var output = await Respond(ctx);
+				await output.WriteTo(response);
 			} catch (HttpException e) {
 				Log.Error(e);
 				response.StatusCode = (int) e.StatusCode;
@@ -51,7 +48,15 @@ namespace DHT.Server.Endpoints {
 			}
 		}
 
-		protected abstract Task<(HttpStatusCode, object?)> Respond(HttpContext ctx);
+		public async Task HandleGet(HttpContext ctx) {
+			await Handle(ctx, ctx.Request.Query["token"]);
+		}
+
+		public async Task HandlePost(HttpContext ctx) {
+			await Handle(ctx, ctx.Request.Headers["X-DHT-Token"]);
+		}
+
+		protected abstract Task<IHttpOutput> Respond(HttpContext ctx);
 
 		protected static async Task<JsonElement> ReadJson(HttpContext ctx) {
 			return await ctx.Request.ReadFromJsonAsync<JsonElement?>() ?? throw new HttpException(HttpStatusCode.UnsupportedMediaType, "This endpoint only accepts JSON.");

app/Server/Endpoints/GetAttachmentEndpoint.cs

@@ -0,0 +1,25 @@
+using System.Net;
+using System.Threading.Tasks;
+using DHT.Server.Data;
+using DHT.Server.Database;
+using DHT.Server.Service;
+using DHT.Utils.Http;
+using Microsoft.AspNetCore.Http;
+
+namespace DHT.Server.Endpoints {
+	sealed class GetAttachmentEndpoint : BaseEndpoint {
+		public GetAttachmentEndpoint(IDatabaseFile db, ServerParameters parameters) : base(db, parameters) {}
+		
+		protected override Task<IHttpOutput> Respond(HttpContext ctx) {
+			string attachmentUrl = WebUtility.UrlDecode((string) ctx.Request.RouteValues["url"]!);
+			DownloadedAttachment? maybeDownloadedAttachment = Db.GetDownloadedAttachment(attachmentUrl);
+
+			if (maybeDownloadedAttachment is {} downloadedAttachment) {
+				return Task.FromResult<IHttpOutput>(new HttpOutput.File(downloadedAttachment.Type, downloadedAttachment.Data));
+			}
+			else {
+				return Task.FromResult<IHttpOutput>(new HttpOutput.Redirect(attachmentUrl, permanent: false));
+			}
+		}
+	}
+}

app/Server/Endpoints/TrackChannelEndpoint.cs

@@ -11,7 +11,7 @@ namespace DHT.Server.Endpoints {
 	sealed class TrackChannelEndpoint : BaseEndpoint {
 		public TrackChannelEndpoint(IDatabaseFile db, ServerParameters parameters) : base(db, parameters) {}
 
-		protected override async Task<(HttpStatusCode, object?)> Respond(HttpContext ctx) {
+		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);
@@ -19,7 +19,7 @@ namespace DHT.Server.Endpoints {
 			Db.AddServer(server);
 			Db.AddChannel(channel);
 
-			return (HttpStatusCode.OK, null);
+			return HttpOutput.None;
 		}
 
 		private static Data.Server ReadServer(JsonElement json, string path) => new() {

app/Server/Endpoints/TrackMessagesEndpoint.cs

@@ -17,7 +17,7 @@ namespace DHT.Server.Endpoints {
 	sealed class TrackMessagesEndpoint : BaseEndpoint {
 		public TrackMessagesEndpoint(IDatabaseFile db, ServerParameters parameters) : base(db, parameters) {}
 
-		protected override async Task<(HttpStatusCode, object?)> Respond(HttpContext ctx) {
+		protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
 			var root = await ReadJson(ctx);
 
 			if (root.ValueKind != JsonValueKind.Array) {
@@ -39,7 +39,7 @@ namespace DHT.Server.Endpoints {
 
 			Db.AddMessages(messages);
 
-			return (HttpStatusCode.OK, anyNewMessages ? 1 : 0);
+			return new HttpOutput.Json(anyNewMessages ? 1 : 0);
 		}
 
 		private static Message ReadMessage(JsonElement json, string path) => new() {
@@ -61,7 +61,9 @@ namespace DHT.Server.Endpoints {
 			Name = ele.RequireString("name", path),
 			Type = ele.HasKey("type") ? ele.RequireString("type", path) : null,
 			Url = ele.RequireString("url", path),
-			Size = (ulong) ele.RequireLong("size", path)
+			Size = (ulong) ele.RequireLong("size", path),
+			Width = ele.HasKey("width") ? ele.RequireInt("width", path) : null,
+			Height = ele.HasKey("height") ? ele.RequireInt("height", path) : null
 		}).DistinctByKeyStable(static attachment => {
 			// Some Discord messages have duplicate attachments with the same id for unknown reasons.
 			return attachment.Id;

app/Server/Endpoints/TrackUsersEndpoint.cs

@@ -11,7 +11,7 @@ namespace DHT.Server.Endpoints {
 	sealed class TrackUsersEndpoint : BaseEndpoint {
 		public TrackUsersEndpoint(IDatabaseFile db, ServerParameters parameters) : base(db, parameters) {}
 
-		protected override async Task<(HttpStatusCode, object?)> Respond(HttpContext ctx) {
+		protected override async Task<IHttpOutput> Respond(HttpContext ctx) {
 			var root = await ReadJson(ctx);
 
 			if (root.ValueKind != JsonValueKind.Array) {
@@ -27,7 +27,7 @@ namespace DHT.Server.Endpoints {
 
 			Db.AddUsers(users);
 
-			return (HttpStatusCode.OK, null);
+			return HttpOutput.None;
 		}
 
 		private static User ReadUser(JsonElement json, string path) => new() {

app/Server/Server.csproj

@@ -20,7 +20,7 @@
     <FrameworkReference Include="Microsoft.AspNetCore.App" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Microsoft.Data.Sqlite" Version="6.0.5" />
+    <PackageReference Include="Microsoft.Data.Sqlite" Version="6.0.7" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Utils\Utils.csproj" />

app/Server/Service/ServerStartup.cs

@@ -9,6 +9,13 @@ using Microsoft.Extensions.Hosting;
 
 namespace DHT.Server.Service {
 	sealed class Startup {
+		private static readonly string[] AllowedOrigins = {
+			"https://discord.com",
+			"https://ptb.discord.com",
+			"https://canary.discord.com",
+			"https://discordapp.com"
+		};
+
 		public void ConfigureServices(IServiceCollection services) {
 			services.Configure<JsonOptions>(static options => {
 				options.SerializerOptions.NumberHandling = JsonNumberHandling.Strict;
@@ -16,7 +23,7 @@ namespace DHT.Server.Service {
 
 			services.AddCors(static cors => {
 				cors.AddDefaultPolicy(static builder => {
-					builder.WithOrigins("https://discord.com", "https://discordapp.com").AllowCredentials().AllowAnyMethod().AllowAnyHeader();
+					builder.WithOrigins(AllowedOrigins).AllowCredentials().AllowAnyMethod().AllowAnyHeader();
 				});
 			});
 		}
@@ -27,13 +34,16 @@ namespace DHT.Server.Service {
 			app.UseCors();
 			app.UseEndpoints(endpoints => {
 				TrackChannelEndpoint trackChannel = new(db, parameters);
-				endpoints.MapPost("/track-channel", async context => await trackChannel.Handle(context));
+				endpoints.MapPost("/track-channel", async context => await trackChannel.HandlePost(context));
 
 				TrackUsersEndpoint trackUsers = new(db, parameters);
-				endpoints.MapPost("/track-users", async context => await trackUsers.Handle(context));
+				endpoints.MapPost("/track-users", async context => await trackUsers.HandlePost(context));
 
 				TrackMessagesEndpoint trackMessages = new(db, parameters);
-				endpoints.MapPost("/track-messages", async context => await trackMessages.Handle(context));
+				endpoints.MapPost("/track-messages", async context => await trackMessages.HandlePost(context));
+
+				GetAttachmentEndpoint getAttachment = new(db, parameters);
+				endpoints.MapGet("/get-attachment/{url}", async context => await getAttachment.HandleGet(context));
 			});
 		}
 	}

app/Utils/Http/HttpOutput.cs

@@ -0,0 +1,56 @@
+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 Json : IHttpOutput {
+			private readonly object? obj;
+			
+			public Json(object? obj) {
+				this.obj = obj;
+			}
+
+			public Task WriteTo(HttpResponse response) {
+				return response.WriteAsJsonAsync(obj);
+			}
+		}
+
+		public sealed class File : IHttpOutput {
+			private readonly string? contentType;
+			private readonly byte[] bytes;
+			
+			public File(string? contentType, byte[] bytes) {
+				this.contentType = contentType;
+				this.bytes = bytes;
+			}
+
+			public async Task WriteTo(HttpResponse response) {
+				response.ContentType = contentType ?? string.Empty;
+				await response.Body.WriteAsync(bytes);
+			}
+		}
+
+		public sealed class Redirect : IHttpOutput {
+			private readonly string url;
+			private readonly bool permanent;
+
+			public Redirect(string url, bool permanent) {
+				this.url = url;
+				this.permanent = permanent;
+			}
+
+			public Task WriteTo(HttpResponse response) {
+				response.Redirect(url, permanent);
+				return Task.CompletedTask;
+			}
+		}
+	}
+}

app/Utils/Http/IHttpOutput.cs

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

app/Utils/Utils.csproj

@@ -17,7 +17,10 @@
     <DebugType>none</DebugType>
   </PropertyGroup>
   <ItemGroup>
-    <PackageReference Include="JetBrains.Annotations" Version="10.3.0" />
+    <FrameworkReference Include="Microsoft.AspNetCore.App" />
+  </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="JetBrains.Annotations" Version="2022.1.0" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="..\Version.cs" Link="Version.cs" />

app/Version.cs

@@ -7,6 +7,6 @@ using DHT.Utils;
 
 namespace DHT.Utils {
 	static class Version {
-		public const string Tag = "36.2.0.0";
+		public const string Tag = "37.1.0.0";
 	}
 }