Show downloaded attachments when viewing via Open Viewer

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/Viewer/scripts/discord.js

@@ -129,7 +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
@@ -240,19 +240,11 @@ const DISCORD = (function() {
 					}
 					
 					return value.map(attachment => {
-						const url = DOM.tryParseUrl(attachment.url);
+						if (DISCORD.isImageAttachment(attachment) && SETTINGS.enableImagePreviews) {
-						
-						if (url != null && isImageUrl(url) && SETTINGS.enableImagePreviews) {
 							return templateEmbedImage.apply({ url: attachment.url, src: attachment.url });
 						}
 						else {
-							const path = url == null ? attachment.url : url.pathname;
+							return templateAttachmentDownload.apply(attachment);
-							const sliced = path.split("/");
-							
-							return templateAttachmentDownload.apply({
-								"url": attachment.url,
-								"filename": sliced[sliced.length - 1]
-							});
 						}
 					}).join("");
 				}

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 +166,9 @@ namespace DHT.Server.Database.Export {
 					}
 
 					if (!message.Attachments.IsEmpty) {
-						obj["a"] = message.Attachments.Select(static attachment => new Dictionary<string, object> {
+						obj["a"] = message.Attachments.Select(attachment => new Dictionary<string, object> {
-							{ "url", attachment.Url }
+							{ "url", strategy.GetAttachmentUrl(attachment) },
+							{ "name", Uri.TryCreate(attachment.Url, UriKind.Absolute, out var uri) ? Path.GetFileName(uri.LocalPath) : attachment.Url }
 						}).ToArray();
 					}
 

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/SqliteDatabaseFile.cs

@@ -470,6 +470,28 @@ 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");

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 (token.Count != 1 || token[0] != parameters.Token) {
-			if (requestToken.Count != 1 || requestToken[0] != parameters.Token) {
+				Log.Error("Token: " + (token.Count == 1 ? token[0] : "<missing>"));
-				Log.Error("Token: " + (requestToken.Count == 1 ? requestToken[0] : "<missing>"));
 				response.StatusCode = (int) HttpStatusCode.Forbidden;
 				return;
 			}
 
 			try {
-				var (statusCode, output) = await Respond(ctx);
+				response.StatusCode = (int) HttpStatusCode.OK;
-				response.StatusCode = (int) statusCode;
+				var output = await Respond(ctx);
-
+				await output.WriteTo(response);
-				if (output != null) {
-					await response.WriteAsJsonAsync(output);
-				}
 			} 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() {

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/Service/ServerStartup.cs

@@ -34,13 +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

@@ -16,6 +16,9 @@
     <DebugSymbols>true</DebugSymbols>
     <DebugType>none</DebugType>
   </PropertyGroup>
+  <ItemGroup>
+    <FrameworkReference Include="Microsoft.AspNetCore.App" />
+  </ItemGroup>
   <ItemGroup>
     <PackageReference Include="JetBrains.Annotations" Version="10.3.0" />
   </ItemGroup>