Update version

Fixes #344

Changelog.md

@@ -1,3 +1,31 @@
+### v2.22 (12-Aug-2020)
+
+- [GUI] Improved the channel list by adding collapsible category groups. (Thanks [@CarJem Generations](https://github.com/CarJem))
+- [GUI] Improved exporting options by adding a set of controls that can be used to limit the date range of the export down to minutes. Previously it was only possible to configure the date range without the time component. (Thanks [@CarJem Generations](https://github.com/CarJem))
+- [HTML] Fixed an issue where the export didn't reflect changes in nicknames between messages sent by bots. This affected chat logs that contained interactions with the Tupperbox bot. (Thanks [@CarJem Generations](https://github.com/CarJem))
+- [CLI] Fixed an issue where the application crashed if there were two environment variables defined that had the same name but in different case.
+
+### v2.21.2 (30-Jul-2020)
+
+- [GUI] When copy-pasting token, any surrounding spaces are now discarded, in addition to double quotes.
+- [HTML] Changed underlying templating engine to provide higher performance and better error messages. New templating engine adds a small cold start, but any export after the first should be faster.
+- Changed naming schema for downloaded media so that it follows `<original filename> (nn)` format rather than `<original filename>-salt`.
+- [HTML] Fixed an issue where downloaded media was sometimes inaccessible due to reserved characters appearing in the URL.
+- Fixed an issue where the application crashed when trying to download media with a file name that exceeds system's maximum allowed length.
+- Fixed an issue where the application crashed when trying to download media with illegal characters in the file name.
+
+### v2.21.1 (19-Jul-2020)
+
+- Fixed an issue where the export crashed if an embedded image has been deleted. Such media files are now ignored.
+- Changed the naming convention for downloaded media files so that the original file names are used when possible.
+
+### v2.21 (18-Jul-2020)
+
+- Added a new option that enables self-contained exports for all output formats. You can turn it on in the export setup dialog in GUI or using the `--media` option in CLI. When using this, the application will additionally download any media content directly referenced from the exported file instead of linking back to Discord CDN. The files which are downloaded include: guild icons, user avatars, attachments, embedded images, reaction emojis. Note that only files which are actually referenced by the export are downloaded, which means that, for example, user avatars will not be downloaded when using plain text export format. This option is not meant to enable complete offline viewing for HTML exports, but rather to make it easier to archive media content that may eventually get deleted from Discord servers. Also keep in mind that this option may make the export drastically slower and the total file size larger.
+- Changed "discordapp.com" to "discord.com" where applicable as Discord is migrating to a new domain. CDN will remain on "cdn.discordapp.com" for the foreseeable future.
+
+Note that all existing and current HTML exports will likely not render accurately because Discord enabled CORS for their font resources, which prevents them from loading locally. Please refer to [issue #322](https://github.com/Tyrrrz/DiscordChatExporter/issues/322) for discussion on this topic. 
+
 ### v2.20 (27-Apr-2020)
 
 - [CLI] Added environment variables as fallback for `--token` and `--bot` options. They are `DISCORD_TOKEN` and `DISCORD_TOKEN_BOT` respectively.

DiscordChatExporter.Cli/Commands/Base/ExportCommandBase.cs

@@ -11,12 +11,12 @@ namespace DiscordChatExporter.Cli.Commands.Base
 {
     public abstract class ExportCommandBase : TokenCommandBase
     {
-        [CommandOption("format", 'f', Description = "Output file format.")]
-        public ExportFormat ExportFormat { get; set; } = ExportFormat.HtmlDark;
-
         [CommandOption("output", 'o', Description = "Output file or directory path.")]
         public string OutputPath { get; set; } = Directory.GetCurrentDirectory();
 
+        [CommandOption("format", 'f', Description = "Output file format.")]
+        public ExportFormat ExportFormat { get; set; } = ExportFormat.HtmlDark;
+
         [CommandOption("after", Description = "Limit to messages sent after this date.")]
         public DateTimeOffset? After { get; set; }
 
@@ -26,6 +26,9 @@ namespace DiscordChatExporter.Cli.Commands.Base
         [CommandOption("partition", 'p', Description = "Split output into partitions limited to this number of messages.")]
         public int? PartitionLimit { get; set; }
 
+        [CommandOption("media", Description = "Download referenced media content.")]
+        public bool ShouldDownloadMedia { get; set; }
+
         [CommandOption("dateformat", Description = "Date format used in output.")]
         public string DateFormat { get; set; } = "dd-MMM-yy hh:mm tt";
 
@@ -36,9 +39,19 @@ namespace DiscordChatExporter.Cli.Commands.Base
             console.Output.Write($"Exporting channel '{channel.Category} / {channel.Name}'... ");
             var progress = console.CreateProgressTicker();
 
-            await GetChannelExporter().ExportAsync(guild, channel,
+            var request = new ExportRequest(
-                OutputPath, ExportFormat, DateFormat, PartitionLimit,
+                guild,
-                After, Before, progress);
+                channel,
+                OutputPath,
+                ExportFormat,
+                After,
+                Before,
+                PartitionLimit,
+                ShouldDownloadMedia,
+                DateFormat
+            );
+
+            await GetChannelExporter().ExportChannelAsync(request, progress);
 
             console.Output.WriteLine();
             console.Output.WriteLine("Done.");

DiscordChatExporter.Cli/Commands/Base/ExportMultipleCommandBase.cs

@@ -7,6 +7,7 @@ using CliFx.Attributes;
 using CliFx.Utilities;
 using DiscordChatExporter.Domain.Discord.Models;
 using DiscordChatExporter.Domain.Exceptions;
+using DiscordChatExporter.Domain.Exporting;
 using DiscordChatExporter.Domain.Utilities;
 using Gress;
 using Tyrrrz.Extensions;
@@ -15,13 +16,12 @@ namespace DiscordChatExporter.Cli.Commands.Base
 {
     public abstract class ExportMultipleCommandBase : ExportCommandBase
     {
-        [CommandOption("parallel", Description = "Export this number of separate channels in parallel.")]
+        [CommandOption("parallel", Description = "Export this number of channels in parallel.")]
         public int ParallelLimit { get; set; } = 1;
 
         protected async ValueTask ExportMultipleAsync(IConsole console, IReadOnlyList<Channel> channels)
         {
-            // This uses a separate route from ExportCommandBase because the progress ticker is not thread-safe
+            // HACK: this uses a separate route from ExportCommandBase because the progress ticker is not thread-safe
-            // Ugly code ahead. Will need to refactor.
 
             console.Output.Write($"Exporting {channels.Count} channels... ");
             var progress = console.CreateProgressTicker();
@@ -39,9 +39,19 @@ namespace DiscordChatExporter.Cli.Commands.Base
                 {
                     var guild = await GetDiscordClient().GetGuildAsync(channel.GuildId);
 
-                    await GetChannelExporter().ExportAsync(guild, channel,
+                    var request = new ExportRequest(
-                        OutputPath, ExportFormat, DateFormat, PartitionLimit,
+                        guild,
-                        After, Before, operation);
+                        channel,
+                        OutputPath,
+                        ExportFormat,
+                        After,
+                        Before,
+                        PartitionLimit,
+                        ShouldDownloadMedia,
+                        DateFormat
+                    );
+
+                    await GetChannelExporter().ExportChannelAsync(request, operation);
 
                     Interlocked.Increment(ref successfulExportCount);
                 }

DiscordChatExporter.Cli/Commands/GuideCommand.cs

@@ -14,7 +14,7 @@ namespace DiscordChatExporter.Cli.Commands
             console.Output.WriteLine(" 1. Open Discord");
             console.Output.WriteLine(" 2. Press Ctrl+Shift+I to show developer tools");
             console.Output.WriteLine(" 3. Navigate to the Application tab");
-            console.Output.WriteLine(" 4. Select \"Local Storage\" > \"https://discordapp.com\" on the left");
+            console.Output.WriteLine(" 4. Select \"Local Storage\" > \"https://discord.com\" on the left");
             console.Output.WriteLine(" 5. Press Ctrl+R to reload");
             console.Output.WriteLine(" 6. Find \"token\" at the bottom and copy the value");
             console.Output.WriteLine(" *  Automating user accounts is technically against TOS, use at your own risk.");

DiscordChatExporter.Cli/DiscordChatExporter.Cli.csproj

@@ -7,7 +7,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="CliFx" Version="1.1.0" />
+    <PackageReference Include="CliFx" Version="1.3.2" />
     <PackageReference Include="Gress" Version="1.2.0" />
     <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
   </ItemGroup>

DiscordChatExporter.Domain/Discord/AuthToken.cs

@@ -16,9 +16,11 @@ namespace DiscordChatExporter.Domain.Discord
             Value = value;
         }
 
-        public AuthenticationHeaderValue GetAuthorizationHeader() => Type == AuthTokenType.User
+        public AuthenticationHeaderValue GetAuthorizationHeader() => Type switch
-            ? new AuthenticationHeaderValue(Value)
+        {
-            : new AuthenticationHeaderValue("Bot", Value);
+            AuthTokenType.Bot => new AuthenticationHeaderValue("Bot", Value),
+            _ => new AuthenticationHeaderValue(Value)
+        };
 
         public override string ToString() => Value;
     }

DiscordChatExporter.Domain/Discord/DiscordClient.cs

@@ -8,25 +8,26 @@ using System.Threading.Tasks;
 using DiscordChatExporter.Domain.Discord.Models;
 using DiscordChatExporter.Domain.Exceptions;
 using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 using Polly;
 
 namespace DiscordChatExporter.Domain.Discord
 {
-    public partial class DiscordClient
+    public class DiscordClient
     {
         private readonly AuthToken _token;
-        private readonly HttpClient _httpClient;
+        private readonly HttpClient _httpClient = Singleton.HttpClient;
         private readonly IAsyncPolicy<HttpResponseMessage> _httpRequestPolicy;
 
-        private readonly Uri _baseUri = new Uri("https://discordapp.com/api/v6/", UriKind.Absolute);
+        private readonly Uri _baseUri = new Uri("https://discord.com/api/v6/", UriKind.Absolute);
 
-        public DiscordClient(AuthToken token, HttpClient httpClient)
+        public DiscordClient(AuthToken token)
         {
             _token = token;
-            _httpClient = httpClient;
 
             // Discord seems to always respond with 429 on the first request with unreasonable wait time (10+ minutes).
-            // For that reason the policy will start respecting their retry-after header only after Nth failed response.
+            // For that reason the policy will ignore such errors at first, then wait a constant amount of time, and
+            // finally wait the specified amount of time, based on how many requests have failed in a row.
             _httpRequestPolicy = Policy
                 .HandleResult<HttpResponseMessage>(m => m.StatusCode == HttpStatusCode.TooManyRequests)
                 .OrResult(m => m.StatusCode >= HttpStatusCode.InternalServerError)
@@ -41,26 +42,19 @@ namespace DiscordChatExporter.Domain.Discord
 
                         return result.Result.Headers.RetryAfter.Delta ?? TimeSpan.FromSeconds(10 * i);
                     },
-                    (response, timespan, retryCount, context) => Task.CompletedTask);
+                    (response, timespan, retryCount, context) => Task.CompletedTask
+                );
         }
 
-        public DiscordClient(AuthToken token)
+        private async ValueTask<HttpResponseMessage> GetResponseAsync(string url) => await _httpRequestPolicy.ExecuteAsync(async () =>
-            : this(token, LazyHttpClient.Value)
-        {
-        }
-
-        private async Task<HttpResponseMessage> GetResponseAsync(string url)
-        {
-            return await _httpRequestPolicy.ExecuteAsync(async () =>
         {
             using var request = new HttpRequestMessage(HttpMethod.Get, new Uri(_baseUri, url));
             request.Headers.Authorization = _token.GetAuthorizationHeader();
 
             return await _httpClient.SendAsync(request, HttpCompletionOption.ResponseHeadersRead);
         });
-        }
 
-        private async Task<JsonElement> GetJsonResponseAsync(string url)
+        private async ValueTask<JsonElement> GetJsonResponseAsync(string url)
         {
             using var response = await GetResponseAsync(url);
 
@@ -78,7 +72,7 @@ namespace DiscordChatExporter.Domain.Discord
             return await response.Content.ReadAsJsonAsync();
         }
 
-        private async Task<JsonElement?> TryGetJsonResponseAsync(string url)
+        private async ValueTask<JsonElement?> TryGetJsonResponseAsync(string url)
         {
             using var response = await GetResponseAsync(url);
 
@@ -97,15 +91,14 @@ namespace DiscordChatExporter.Domain.Discord
                 var url = new UrlBuilder()
                     .SetPath("users/@me/guilds")
                     .SetQueryParameter("limit", "100")
-                    .SetQueryParameterIfNotNullOrWhiteSpace("after", afterId)
+                    .SetQueryParameter("after", afterId)
                     .Build();
 
                 var response = await GetJsonResponseAsync(url);
 
                 var isEmpty = true;
-                foreach (var guildJson in response.EnumerateArray())
+                foreach (var guild in response.EnumerateArray().Select(Guild.Parse))
                 {
-                    var guild = Guild.Parse(guildJson);
                     yield return guild;
 
                     afterId = guild.Id;
@@ -117,7 +110,7 @@ namespace DiscordChatExporter.Domain.Discord
             }
         }
 
-        public async Task<Guild> GetGuildAsync(string guildId)
+        public async ValueTask<Guild> GetGuildAsync(string guildId)
         {
             if (guildId == Guild.DirectMessages.Id)
                 return Guild.DirectMessages;
@@ -174,7 +167,7 @@ namespace DiscordChatExporter.Domain.Discord
                 yield return Role.Parse(roleJson);
         }
 
-        public async Task<Member?> TryGetGuildMemberAsync(string guildId, User user)
+        public async ValueTask<Member?> TryGetGuildMemberAsync(string guildId, User user)
         {
             if (guildId == Guild.DirectMessages.Id)
                 return Member.CreateForUser(user);
@@ -183,13 +176,13 @@ namespace DiscordChatExporter.Domain.Discord
             return response?.Pipe(Member.Parse);
         }
 
-        private async Task<string> GetChannelCategoryAsync(string channelParentId)
+        private async ValueTask<string> GetChannelCategoryAsync(string channelParentId)
         {
             var response = await GetJsonResponseAsync($"channels/{channelParentId}");
             return response.GetProperty("name").GetString();
         }
 
-        public async Task<Channel> GetChannelAsync(string channelId)
+        public async ValueTask<Channel> GetChannelAsync(string channelId)
         {
             var response = await GetJsonResponseAsync($"channels/{channelId}");
 
@@ -201,12 +194,12 @@ namespace DiscordChatExporter.Domain.Discord
             return Channel.Parse(response, category);
         }
 
-        private async Task<Message?> TryGetLastMessageAsync(string channelId, DateTimeOffset? before = null)
+        private async ValueTask<Message?> TryGetLastMessageAsync(string channelId, DateTimeOffset? before = null)
         {
             var url = new UrlBuilder()
                 .SetPath($"channels/{channelId}/messages")
                 .SetQueryParameter("limit", "1")
-                .SetQueryParameterIfNotNullOrWhiteSpace("before", before?.ToSnowflake())
+                .SetQueryParameter("before", before?.ToSnowflake())
                 .Build();
 
             var response = await GetJsonResponseAsync(url);
@@ -219,11 +212,15 @@ namespace DiscordChatExporter.Domain.Discord
             DateTimeOffset? before = null,
             IProgress<double>? progress = null)
         {
-            // Get the last message in the specified range
+            // Get the last message in the specified range.
+            // This snapshots the boundaries, which means that messages posted after the exported started
+            // will not appear in the output.
+            // Additionally, it provides the date of the last message, which is used to calculate progress.
             var lastMessage = await TryGetLastMessageAsync(channelId, before);
             if (lastMessage == null || lastMessage.Timestamp < after)
                 yield break;
 
+            // Keep track of first message in range in order to calculate progress
             var firstMessage = default(Message);
             var afterId = after?.ToSnowflake() ?? "0";
 
@@ -267,19 +264,4 @@ namespace DiscordChatExporter.Domain.Discord
             }
         }
     }
-
-    public partial class DiscordClient
-    {
-        private static readonly Lazy<HttpClient> LazyHttpClient = new Lazy<HttpClient>(() =>
-        {
-            var handler = new HttpClientHandler();
-
-            if (handler.SupportsAutomaticDecompression)
-                handler.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
-
-            handler.UseCookies = false;
-
-            return new HttpClient(handler, true);
-        });
-    }
 }

DiscordChatExporter.Domain/Discord/Models/Attachment.cs

@@ -3,11 +3,11 @@ using System.IO;
 using System.Linq;
 using System.Text.Json;
 using DiscordChatExporter.Domain.Discord.Models.Common;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#attachment-object
+    // https://discord.com/developers/docs/resources/channel#attachment-object
     public partial class Attachment : IHasId
     {
         public string Id { get; }

DiscordChatExporter.Domain/Discord/Models/Channel.cs

@@ -1,12 +1,12 @@
 using System.Linq;
 using System.Text.Json;
 using DiscordChatExporter.Domain.Discord.Models.Common;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#channel-object-channel-types
+    // https://discord.com/developers/docs/resources/channel#channel-object-channel-types
     // Order of enum fields needs to match the order in the docs.
     public enum ChannelType
     {
@@ -19,7 +19,7 @@ namespace DiscordChatExporter.Domain.Discord.Models
         GuildStore
     }
 
-    // https://discordapp.com/developers/docs/resources/channel#channel-object
+    // https://discord.com/developers/docs/resources/channel#channel-object
     public partial class Channel : IHasId
     {
         public string Id { get; }
@@ -85,7 +85,8 @@ namespace DiscordChatExporter.Domain.Discord.Models
                 guildId ?? Guild.DirectMessages.Id,
                 category ?? GetDefaultCategory(type),
                 name,
-                topic);
+                topic
+            );
         }
     }
 }

DiscordChatExporter.Domain/Discord/Models/Embed.cs

@@ -3,11 +3,11 @@ using System.Collections.Generic;
 using System.Drawing;
 using System.Linq;
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object
+    // https://discord.com/developers/docs/resources/channel#embed-object
     public partial class Embed
     {
         public string? Title { get; }

DiscordChatExporter.Domain/Discord/Models/EmbedAuthor.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object-embed-author-structure
+    // https://discord.com/developers/docs/resources/channel#embed-object-embed-author-structure
     public partial class EmbedAuthor
     {
         public string? Name { get; }

DiscordChatExporter.Domain/Discord/Models/EmbedField.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object-embed-field-structure
+    // https://discord.com/developers/docs/resources/channel#embed-object-embed-field-structure
     public partial class EmbedField
     {
         public string Name { get; }

DiscordChatExporter.Domain/Discord/Models/EmbedFooter.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object-embed-footer-structure
+    // https://discord.com/developers/docs/resources/channel#embed-object-embed-footer-structure
     public partial class EmbedFooter
     {
         public string Text { get; }

DiscordChatExporter.Domain/Discord/Models/EmbedImage.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#embed-object-embed-image-structure
+    // https://discord.com/developers/docs/resources/channel#embed-object-embed-image-structure
     public partial class EmbedImage
     {
         public string? Url { get; }

DiscordChatExporter.Domain/Discord/Models/Emoji.cs

@@ -2,12 +2,12 @@
 using System.Linq;
 using System.Text;
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/emoji#emoji-object
+    // https://discord.com/developers/docs/resources/emoji#emoji-object
     public partial class Emoji
     {
         public string? Id { get; }

DiscordChatExporter.Domain/Discord/Models/Guild.cs

@@ -3,7 +3,7 @@ using DiscordChatExporter.Domain.Discord.Models.Common;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/guild#guild-object
+    // https://discord.com/developers/docs/resources/guild#guild-object
     public partial class Guild : IHasId
     {
         public string Id { get; }
@@ -12,12 +12,11 @@ namespace DiscordChatExporter.Domain.Discord.Models
 
         public string IconUrl { get; }
 
-        public Guild(string id, string name, string? iconHash)
+        public Guild(string id, string name, string iconUrl)
         {
             Id = id;
             Name = name;
-
+            IconUrl = iconUrl;
-            IconUrl = GetIconUrl(id, iconHash);
         }
 
         public override string ToString() => Name;
@@ -26,12 +25,13 @@ namespace DiscordChatExporter.Domain.Discord.Models
     public partial class Guild
     {
         public static Guild DirectMessages { get; } =
-            new Guild("@me", "Direct Messages", null);
+            new Guild("@me", "Direct Messages", GetDefaultIconUrl());
 
-        private static string GetIconUrl(string id, string? iconHash) =>
+        private static string GetDefaultIconUrl() =>
-            !string.IsNullOrWhiteSpace(iconHash)
+            "https://cdn.discordapp.com/embed/avatars/0.png";
-                ? $"https://cdn.discordapp.com/icons/{id}/{iconHash}.png"
+
-                : "https://cdn.discordapp.com/embed/avatars/0.png";
+        private static string GetIconUrl(string id, string iconHash) =>
+            $"https://cdn.discordapp.com/icons/{id}/{iconHash}.png";
 
         public static Guild Parse(JsonElement json)
         {
@@ -39,7 +39,11 @@ namespace DiscordChatExporter.Domain.Discord.Models
             var name = json.GetProperty("name").GetString();
             var iconHash = json.GetProperty("icon").GetString();
 
-            return new Guild(id, name, iconHash);
+            var iconUrl = !string.IsNullOrWhiteSpace(iconHash)
+                ? GetIconUrl(id, iconHash)
+                : GetDefaultIconUrl();
+
+            return new Guild(id, name, iconUrl);
         }
     }
 }

DiscordChatExporter.Domain/Discord/Models/Member.cs

@@ -3,11 +3,11 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text.Json;
 using DiscordChatExporter.Domain.Discord.Models.Common;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/guild#guild-member-object
+    // https://discord.com/developers/docs/resources/guild#guild-member-object
     public partial class Member : IHasId
     {
         public string Id => User.Id;

DiscordChatExporter.Domain/Discord/Models/Message.cs

@@ -3,11 +3,11 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text.Json;
 using DiscordChatExporter.Domain.Discord.Models.Common;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#message-object-message-types
+    // https://discord.com/developers/docs/resources/channel#message-object-message-types
     public enum MessageType
     {
         Default,
@@ -20,7 +20,7 @@ namespace DiscordChatExporter.Domain.Discord.Models
         GuildMemberJoin
     }
 
-    // https://discordapp.com/developers/docs/resources/channel#message-object
+    // https://discord.com/developers/docs/resources/channel#message-object
     public partial class Message : IHasId
     {
         public string Id { get; }
@@ -71,10 +71,7 @@ namespace DiscordChatExporter.Domain.Discord.Models
             MentionedUsers = mentionedUsers;
         }
 
-        public override string ToString() =>
+        public override string ToString() => Content;
-            Content ?? (Embeds.Any()
-                ? "<embed>"
-                : "<no content>");
     }
 
     public partial class Message

DiscordChatExporter.Domain/Discord/Models/Reaction.cs

@@ -1,9 +1,9 @@
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/channel#reaction-object
+    // https://discord.com/developers/docs/resources/channel#reaction-object
     public partial class Reaction
     {
         public Emoji Emoji { get; }

DiscordChatExporter.Domain/Discord/Models/Role.cs

@@ -1,10 +1,10 @@
 using System.Drawing;
 using System.Text.Json;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/topics/permissions#role-object
+    // https://discord.com/developers/docs/topics/permissions#role-object
     public partial class Role
     {
         public string Id { get; }

DiscordChatExporter.Domain/Discord/Models/User.cs

@@ -1,11 +1,11 @@
 using System;
 using System.Text.Json;
 using DiscordChatExporter.Domain.Discord.Models.Common;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Discord.Models
 {
-    // https://discordapp.com/developers/docs/resources/user#user-object
+    // https://discord.com/developers/docs/resources/user#user-object
     public partial class User : IHasId
     {
         public string Id { get; }
@@ -20,14 +20,13 @@ namespace DiscordChatExporter.Domain.Discord.Models
 
         public string AvatarUrl { get; }
 
-        public User(string id, bool isBot, int discriminator, string name, string? avatarHash)
+        public User(string id, bool isBot, int discriminator, string name, string avatarUrl)
         {
             Id = id;
             IsBot = isBot;
             Discriminator = discriminator;
             Name = name;
-
+            AvatarUrl = avatarUrl;
-            AvatarUrl = GetAvatarUrl(id, discriminator, avatarHash);
         }
 
         public override string ToString() => FullName;
@@ -35,10 +34,10 @@ namespace DiscordChatExporter.Domain.Discord.Models
 
     public partial class User
     {
-        private static string GetAvatarUrl(string id, int discriminator, string? avatarHash)
+        private static string GetDefaultAvatarUrl(int discriminator) =>
-        {
+            $"https://cdn.discordapp.com/embed/avatars/{discriminator % 5}.png";
-            // Custom avatar
+
-            if (!string.IsNullOrWhiteSpace(avatarHash))
+        private static string GetAvatarUrl(string id, string avatarHash)
         {
             // Animated
             if (avatarHash.StartsWith("a_", StringComparison.Ordinal))
@@ -48,10 +47,6 @@ namespace DiscordChatExporter.Domain.Discord.Models
             return $"https://cdn.discordapp.com/avatars/{id}/{avatarHash}.png";
         }
 
-            // Default avatar
-            return $"https://cdn.discordapp.com/embed/avatars/{discriminator % 5}.png";
-        }
-
         public static User Parse(JsonElement json)
         {
             var id = json.GetProperty("id").GetString();
@@ -60,7 +55,11 @@ namespace DiscordChatExporter.Domain.Discord.Models
             var avatarHash = json.GetProperty("avatar").GetString();
             var isBot = json.GetPropertyOrNull("bot")?.GetBoolean() ?? false;
 
-            return new User(id, isBot, discriminator, name, avatarHash);
+            var avatarUrl = !string.IsNullOrWhiteSpace(avatarHash)
+                ? GetAvatarUrl(id, avatarHash)
+                : GetDefaultAvatarUrl(discriminator);
+
+            return new User(id, isBot, discriminator, name, avatarUrl);
         }
     }
 }

DiscordChatExporter.Domain/DiscordChatExporter.Domain.csproj

@@ -2,17 +2,18 @@
   <Import Project="../DiscordChatExporter.props" />
 
   <ItemGroup>
-    <PackageReference Include="Polly" Version="7.2.0" />
+    <PackageReference Include="MiniRazor" Version="1.1.0" />
-    <PackageReference Include="Scriban" Version="2.1.2" />
+    <PackageReference Include="Polly" Version="7.2.1" />
     <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
   </ItemGroup>
 
   <ItemGroup>
-    <EmbeddedResource Include="Exporting\Resources\HtmlCore.css" />
+    <EmbeddedResource Include="Exporting\Writers\Html\Core.css" />
-    <EmbeddedResource Include="Exporting\Resources\HtmlDark.css" />
+    <EmbeddedResource Include="Exporting\Writers\Html\Dark.css" />
-    <EmbeddedResource Include="Exporting\Resources\HtmlLayoutTemplate.html" />
+    <EmbeddedResource Include="Exporting\Writers\Html\Light.css" />
-    <EmbeddedResource Include="Exporting\Resources\HtmlLight.css" />
+    <EmbeddedResource Include="Exporting\Writers\Html\PreambleTemplate.cshtml" />
-    <EmbeddedResource Include="Exporting\Resources\HtmlMessageGroupTemplate.html" />
+    <EmbeddedResource Include="Exporting\Writers\Html\PostambleTemplate.cshtml" />
+    <EmbeddedResource Include="Exporting\Writers\Html\MessageGroupTemplate.cshtml" />
   </ItemGroup>
 
 </Project>

DiscordChatExporter.Domain/Exceptions/DiscordChatExporterException.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Net.Http;
-using DiscordChatExporter.Domain.Discord.Models;
 
 namespace DiscordChatExporter.Domain.Exceptions
 {
@@ -43,17 +42,14 @@ Failed to perform an HTTP request.
 
         internal static DiscordChatExporterException NotFound()
         {
-            const string message = "Not found.";
+            const string message = "Requested resource does not exist.";
             return new DiscordChatExporterException(message);
         }
 
-        internal static DiscordChatExporterException ChannelEmpty(string channel)
+        internal static DiscordChatExporterException ChannelIsEmpty(string channel)
         {
             var message = $"Channel '{channel}' contains no messages for the specified period.";
             return new DiscordChatExporterException(message);
         }
-
-        internal static DiscordChatExporterException ChannelEmpty(Channel channel) =>
-            ChannelEmpty(channel.Name);
     }
 }

DiscordChatExporter.Domain/Exporting/ChannelExporter.cs

@@ -1,8 +1,6 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
 using DiscordChatExporter.Domain.Discord;
 using DiscordChatExporter.Domain.Discord.Models;
@@ -12,7 +10,7 @@ using DiscordChatExporter.Domain.Utilities;
 
 namespace DiscordChatExporter.Domain.Exporting
 {
-    public partial class ChannelExporter
+    public class ChannelExporter
     {
         private readonly DiscordClient _discord;
 
@@ -20,50 +18,39 @@ namespace DiscordChatExporter.Domain.Exporting
 
         public ChannelExporter(AuthToken token) : this(new DiscordClient(token)) {}
 
-        public async Task ExportAsync(
+        public async ValueTask ExportChannelAsync(ExportRequest request, IProgress<double>? progress = null)
-            Guild guild,
-            Channel channel,
-            string outputPath,
-            ExportFormat format,
-            string dateFormat,
-            int? partitionLimit,
-            DateTimeOffset? after = null,
-            DateTimeOffset? before = null,
-            IProgress<double>? progress = null)
         {
-            var baseFilePath = GetFilePathFromOutputPath(guild, channel, outputPath, format, after, before);
+            // Build context
-
-            // Options
-            var options = new ExportOptions(baseFilePath, format, partitionLimit);
-
-            // Context
             var contextMembers = new HashSet<Member>(IdBasedEqualityComparer.Instance);
-            var contextChannels = await _discord.GetGuildChannelsAsync(guild.Id);
+            var contextChannels = await _discord.GetGuildChannelsAsync(request.Guild.Id);
-            var contextRoles = await _discord.GetGuildRolesAsync(guild.Id);
+            var contextRoles = await _discord.GetGuildRolesAsync(request.Guild.Id);
 
             var context = new ExportContext(
-                guild, channel, after, before, dateFormat,
+                request,
-                contextMembers, contextChannels, contextRoles
+                contextMembers,
+                contextChannels,
+                contextRoles
             );
 
-            await using var messageExporter = new MessageExporter(options, context);
+            // Export messages
+            await using var messageExporter = new MessageExporter(context);
 
             var exportedAnything = false;
             var encounteredUsers = new HashSet<User>(IdBasedEqualityComparer.Instance);
-            await foreach (var message in _discord.GetMessagesAsync(channel.Id, after, before, progress))
+            await foreach (var message in _discord.GetMessagesAsync(request.Channel.Id, request.After, request.Before, progress))
             {
                 // Resolve members for referenced users
                 foreach (var referencedUser in message.MentionedUsers.Prepend(message.Author))
                 {
-                    if (encounteredUsers.Add(referencedUser))
+                    if (!encounteredUsers.Add(referencedUser))
-                    {
+                        continue;
+
                     var member =
-                            await _discord.TryGetGuildMemberAsync(guild.Id, referencedUser) ??
+                        await _discord.TryGetGuildMemberAsync(request.Guild.Id, referencedUser) ??
                         Member.CreateForUser(referencedUser);
 
                     contextMembers.Add(member);
                 }
-                }
 
                 // Export message
                 await messageExporter.ExportMessageAsync(message);
@@ -72,75 +59,7 @@ namespace DiscordChatExporter.Domain.Exporting
 
             // Throw if no messages were exported
             if (!exportedAnything)
-                throw DiscordChatExporterException.ChannelEmpty(channel);
+                throw DiscordChatExporterException.ChannelIsEmpty(request.Channel.Name);
-        }
-    }
-
-    public partial class ChannelExporter
-    {
-        public static string GetDefaultExportFileName(
-            Guild guild,
-            Channel channel,
-            ExportFormat format,
-            DateTimeOffset? after = null,
-            DateTimeOffset? before = null)
-        {
-            var buffer = new StringBuilder();
-
-            // Guild and channel names
-            buffer.Append($"{guild.Name} - {channel.Category} - {channel.Name} [{channel.Id}]");
-
-            // Date range
-            if (after != null || before != null)
-            {
-                buffer.Append(" (");
-
-                // Both 'after' and 'before' are set
-                if (after != null && before != null)
-                {
-                    buffer.Append($"{after:yyyy-MM-dd} to {before:yyyy-MM-dd}");
-                }
-                // Only 'after' is set
-                else if (after != null)
-                {
-                    buffer.Append($"after {after:yyyy-MM-dd}");
-                }
-                // Only 'before' is set
-                else
-                {
-                    buffer.Append($"before {before:yyyy-MM-dd}");
-                }
-
-                buffer.Append(")");
-            }
-
-            // File extension
-            buffer.Append($".{format.GetFileExtension()}");
-
-            // Replace invalid chars
-            foreach (var invalidChar in Path.GetInvalidFileNameChars())
-                buffer.Replace(invalidChar, '_');
-
-            return buffer.ToString();
-        }
-
-        private static string GetFilePathFromOutputPath(
-            Guild guild,
-            Channel channel,
-            string outputPath,
-            ExportFormat format,
-            DateTimeOffset? after = null,
-            DateTimeOffset? before = null)
-        {
-            // Output is a directory
-            if (Directory.Exists(outputPath) || string.IsNullOrWhiteSpace(Path.GetExtension(outputPath)))
-            {
-                var fileName = GetDefaultExportFileName(guild, channel, format, after, before);
-                return Path.Combine(outputPath, fileName);
-            }
-
-            // Output is a file
-            return outputPath;
         }
     }
 }

DiscordChatExporter.Domain/Exporting/ExportContext.cs

@@ -1,22 +1,21 @@
 using System;
 using System.Collections.Generic;
 using System.Drawing;
+using System.IO;
 using System.Linq;
+using System.Net.Http;
+using System.Threading.Tasks;
 using DiscordChatExporter.Domain.Discord.Models;
+using DiscordChatExporter.Domain.Internal.Extensions;
+using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Domain.Exporting
 {
-    public class ExportContext
+    internal class ExportContext
     {
-        public Guild Guild { get; }
+        private readonly MediaDownloader _mediaDownloader;
 
-        public Channel Channel { get; }
+        public ExportRequest Request { get; }
-
-        public DateTimeOffset? After { get; }
-
-        public DateTimeOffset? Before { get; }
-
-        public string DateFormat { get; }
 
         public IReadOnlyCollection<Member> Members { get; }
 
@@ -25,46 +24,71 @@ namespace DiscordChatExporter.Domain.Exporting
         public IReadOnlyCollection<Role> Roles { get; }
 
         public ExportContext(
-            Guild guild,
+            ExportRequest request,
-            Channel channel,
-            DateTimeOffset? after,
-            DateTimeOffset? before,
-            string dateFormat,
             IReadOnlyCollection<Member> members,
             IReadOnlyCollection<Channel> channels,
             IReadOnlyCollection<Role> roles)
         {
-            Guild = guild;
+            Request = request;
-            Channel = channel;
-            After = after;
-            Before = before;
-            DateFormat = dateFormat;
             Members = members;
             Channels = channels;
             Roles = roles;
+
+            _mediaDownloader = new MediaDownloader(request.OutputMediaDirPath);
         }
 
-        public Member? TryGetMentionedMember(string id) =>
+        public string FormatDate(DateTimeOffset date) => date.ToLocalString(Request.DateFormat);
+
+        public Member? TryGetMember(string id) =>
             Members.FirstOrDefault(m => m.Id == id);
 
-        public Channel? TryGetMentionedChannel(string id) =>
+        public Channel? TryGetChannel(string id) =>
             Channels.FirstOrDefault(c => c.Id == id);
 
-        public Role? TryGetMentionedRole(string id) =>
+        public Role? TryGetRole(string id) =>
             Roles.FirstOrDefault(r => r.Id == id);
 
-        public Member? TryGetUserMember(User user) => Members
+        public Color? TryGetUserColor(string id)
-            .FirstOrDefault(m => m.Id == user.Id);
-
-        public Color? TryGetUserColor(User user)
         {
-            var member = TryGetUserMember(user);
+            var member = TryGetMember(id);
             var roles = member?.RoleIds.Join(Roles, i => i, r => r.Id, (_, role) => role);
 
             return roles?
+                .Where(r => r.Color != null)
                 .OrderByDescending(r => r.Position)
                 .Select(r => r.Color)
-                .FirstOrDefault(c => c != null);
+                .FirstOrDefault();
+        }
+
+        public async ValueTask<string> ResolveMediaUrlAsync(string url)
+        {
+            if (!Request.ShouldDownloadMedia)
+                return url;
+
+            try
+            {
+                var filePath = await _mediaDownloader.DownloadAsync(url);
+
+                // We want relative path so that the output files can be copied around without breaking
+                var relativeFilePath = Path.GetRelativePath(Request.OutputBaseDirPath, filePath);
+
+                // For HTML, we need to format the URL properly
+                if (Request.Format == ExportFormat.HtmlDark || Request.Format == ExportFormat.HtmlLight)
+                {
+                    // Need to escape each path segment while keeping the directory separators intact
+                    return relativeFilePath
+                        .Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)
+                        .Select(Uri.EscapeDataString)
+                        .JoinToString(Path.AltDirectorySeparatorChar.ToString());
+                }
+
+                return relativeFilePath;
+            }
+            catch (HttpRequestException)
+            {
+                // We don't want this to crash the exporting process in case of failure
+                return url;
+            }
         }
     }
 }

DiscordChatExporter.Domain/Exporting/ExportOptions.cs

@@ -1,18 +0,0 @@
-namespace DiscordChatExporter.Domain.Exporting
-{
-    public class ExportOptions
-    {
-        public string BaseFilePath { get; }
-
-        public ExportFormat Format { get; }
-
-        public int? PartitionLimit { get; }
-
-        public ExportOptions(string baseFilePath, ExportFormat format, int? partitionLimit)
-        {
-            BaseFilePath = baseFilePath;
-            Format = format;
-            PartitionLimit = partitionLimit;
-        }
-    }
-}

DiscordChatExporter.Domain/Exporting/ExportRequest.cs

@@ -0,0 +1,136 @@
+using System;
+using System.IO;
+using System.Text;
+using DiscordChatExporter.Domain.Discord.Models;
+using DiscordChatExporter.Domain.Internal;
+
+namespace DiscordChatExporter.Domain.Exporting
+{
+    public partial class ExportRequest
+    {
+        public Guild Guild { get; }
+
+        public Channel Channel { get; }
+
+        public string OutputPath { get; }
+
+        public string OutputBaseFilePath { get; }
+
+        public string OutputBaseDirPath { get; }
+
+        public string OutputMediaDirPath { get; }
+
+        public ExportFormat Format { get; }
+
+        public DateTimeOffset? After { get; }
+
+        public DateTimeOffset? Before { get; }
+
+        public int? PartitionLimit { get; }
+
+        public bool ShouldDownloadMedia { get; }
+
+        public string DateFormat { get; }
+
+        public ExportRequest(
+            Guild guild,
+            Channel channel,
+            string outputPath,
+            ExportFormat format,
+            DateTimeOffset? after,
+            DateTimeOffset? before,
+            int? partitionLimit,
+            bool shouldDownloadMedia,
+            string dateFormat)
+        {
+            Guild = guild;
+            Channel = channel;
+            OutputPath = outputPath;
+            Format = format;
+            After = after;
+            Before = before;
+            PartitionLimit = partitionLimit;
+            ShouldDownloadMedia = shouldDownloadMedia;
+            DateFormat = dateFormat;
+
+            OutputBaseFilePath = GetOutputBaseFilePath(
+                guild,
+                channel,
+                outputPath,
+                format,
+                after,
+                before
+            );
+
+            OutputBaseDirPath = Path.GetDirectoryName(OutputBaseFilePath) ?? OutputPath;
+            OutputMediaDirPath = $"{OutputBaseFilePath}_Files{Path.DirectorySeparatorChar}";
+        }
+    }
+
+    public partial class ExportRequest
+    {
+        private static string GetOutputBaseFilePath(
+            Guild guild,
+            Channel channel,
+            string outputPath,
+            ExportFormat format,
+            DateTimeOffset? after = null,
+            DateTimeOffset? before = null)
+        {
+            // Output is a directory
+            if (Directory.Exists(outputPath) || string.IsNullOrWhiteSpace(Path.GetExtension(outputPath)))
+            {
+                var fileName = GetDefaultOutputFileName(guild, channel, format, after, before);
+                return Path.Combine(outputPath, fileName);
+            }
+
+            // Output is a file
+            return outputPath;
+        }
+
+        public static string GetDefaultOutputFileName(
+            Guild guild,
+            Channel channel,
+            ExportFormat format,
+            DateTimeOffset? after = null,
+            DateTimeOffset? before = null)
+        {
+            var buffer = new StringBuilder();
+
+            // Guild and channel names
+            buffer.Append($"{guild.Name} - {channel.Category} - {channel.Name} [{channel.Id}]");
+
+            // Date range
+            if (after != null || before != null)
+            {
+                buffer.Append(" (");
+
+                // Both 'after' and 'before' are set
+                if (after != null && before != null)
+                {
+                    buffer.Append($"{after:yyyy-MM-dd} to {before:yyyy-MM-dd}");
+                }
+                // Only 'after' is set
+                else if (after != null)
+                {
+                    buffer.Append($"after {after:yyyy-MM-dd}");
+                }
+                // Only 'before' is set
+                else
+                {
+                    buffer.Append($"before {before:yyyy-MM-dd}");
+                }
+
+                buffer.Append(")");
+            }
+
+            // File extension
+            buffer.Append($".{format.GetFileExtension()}");
+
+            // Replace invalid chars
+            PathEx.EscapePath(buffer);
+
+            return buffer.ToString();
+        }
+    }
+}

DiscordChatExporter.Domain/Exporting/MediaDownloader.cs

@@ -0,0 +1,55 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Net.Http;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
+
+namespace DiscordChatExporter.Domain.Exporting
+{
+    internal partial class MediaDownloader
+    {
+        private readonly HttpClient _httpClient = Singleton.HttpClient;
+        private readonly string _workingDirPath;
+
+        private readonly Dictionary<string, string> _pathMap = new Dictionary<string, string>();
+
+        public MediaDownloader(string workingDirPath)
+        {
+            _workingDirPath = workingDirPath;
+        }
+
+        public async ValueTask<string> DownloadAsync(string url)
+        {
+            if (_pathMap.TryGetValue(url, out var cachedFilePath))
+                return cachedFilePath;
+
+            var fileName = GetFileNameFromUrl(url);
+            var filePath = PathEx.MakeUniqueFilePath(Path.Combine(_workingDirPath, fileName));
+
+            Directory.CreateDirectory(_workingDirPath);
+
+            await _httpClient.DownloadAsync(url, filePath);
+
+            return _pathMap[url] = filePath;
+        }
+    }
+
+    internal partial class MediaDownloader
+    {
+        private static string GetRandomFileName() => Guid.NewGuid().ToString().Replace("-", "").Substring(0, 16);
+
+        private static string GetFileNameFromUrl(string url)
+        {
+            var originalFileName = Regex.Match(url, @".+/([^?]*)").Groups[1].Value;
+
+            var fileName = !string.IsNullOrWhiteSpace(originalFileName)
+                ? $"{Path.GetFileNameWithoutExtension(originalFileName).Truncate(50)}{Path.GetExtension(originalFileName)}"
+                : GetRandomFileName();
+
+            return PathEx.EscapePath(fileName);
+        }
+    }
+}

DiscordChatExporter.Domain/Exporting/MessageExporter.cs

@@ -8,26 +8,24 @@ namespace DiscordChatExporter.Domain.Exporting
 {
     internal partial class MessageExporter : IAsyncDisposable
     {
-        private readonly ExportOptions _options;
         private readonly ExportContext _context;
 
-        private long _renderedMessageCount;
+        private long _messageCount;
         private int _partitionIndex;
         private MessageWriter? _writer;
 
-        public MessageExporter(ExportOptions options, ExportContext context)
+        public MessageExporter(ExportContext context)
         {
-            _options = options;
             _context = context;
         }
 
         private bool IsPartitionLimitReached() =>
-            _renderedMessageCount > 0 &&
+            _messageCount > 0 &&
-            _options.PartitionLimit != null &&
+            _context.Request.PartitionLimit != null &&
-            _options.PartitionLimit != 0 &&
+            _context.Request.PartitionLimit != 0 &&
-            _renderedMessageCount % _options.PartitionLimit == 0;
+            _messageCount % _context.Request.PartitionLimit == 0;
 
-        private async Task ResetWriterAsync()
+        private async ValueTask ResetWriterAsync()
         {
             if (_writer != null)
             {
@@ -37,7 +35,7 @@ namespace DiscordChatExporter.Domain.Exporting
             }
         }
 
-        private async Task<MessageWriter> GetWriterAsync()
+        private async ValueTask<MessageWriter> GetWriterAsync()
         {
             // Ensure partition limit has not been exceeded
             if (IsPartitionLimitReached())
@@ -50,23 +48,23 @@ namespace DiscordChatExporter.Domain.Exporting
             if (_writer != null)
                 return _writer;
 
-            var filePath = GetPartitionFilePath(_options.BaseFilePath, _partitionIndex);
+            var filePath = GetPartitionFilePath(_context.Request.OutputBaseFilePath, _partitionIndex);
 
-            var dirPath = Path.GetDirectoryName(_options.BaseFilePath);
+            var dirPath = Path.GetDirectoryName(_context.Request.OutputBaseFilePath);
             if (!string.IsNullOrWhiteSpace(dirPath))
                 Directory.CreateDirectory(dirPath);
 
-            var writer = CreateMessageWriter(filePath, _options.Format, _context);
+            var writer = CreateMessageWriter(filePath, _context.Request.Format, _context);
             await writer.WritePreambleAsync();
 
             return _writer = writer;
         }
 
-        public async Task ExportMessageAsync(Message message)
+        public async ValueTask ExportMessageAsync(Message message)
         {
             var writer = await GetWriterAsync();
             await writer.WriteMessageAsync(message);
-            _renderedMessageCount++;
+            _messageCount++;
         }
 
         public async ValueTask DisposeAsync() => await ResetWriterAsync();

DiscordChatExporter.Domain/Exporting/Resources/HtmlLayoutTemplate.html

@@ -1,96 +0,0 @@
-<!DOCTYPE html>
-<html lang="en">
-
-<head>
-    {{~ # Metadata ~}}
-    <title>{{ Context.Guild.Name | html.escape }} - {{ Context.Channel.Name | html.escape }}</title>
-    <meta charset="utf-8">
-    <meta name="viewport" content="width=device-width">
-
-    {{~ # Styles ~}}
-    <style>
-        {{ CoreStyleSheet }}
-    </style>
-    <style>
-        {{ ThemeStyleSheet }}
-    </style>
-
-    {{~ # Syntax highlighting ~}}
-    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.6/styles/{{HighlightJsStyleName}}.min.css">
-    <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.6/highlight.min.js"></script>
-    <script>
-        document.addEventListener('DOMContentLoaded', () => {
-            document.querySelectorAll('.pre--multiline').forEach(block => hljs.highlightBlock(block));
-        });
-    </script>
-
-    {{~ # Local scripts ~}}
-    <script>
-        function scrollToMessage(event, id) {
-            var element = document.getElementById('message-' + id);
-
-            if (element) {
-                event.preventDefault();
-
-                element.classList.add('chatlog__message--highlighted');
-
-                window.scrollTo({
-                    top: element.getBoundingClientRect().top - document.body.getBoundingClientRect().top - (window.innerHeight / 2),
-                    behavior: 'smooth'
-                });
-
-                window.setTimeout(function() {
-                    element.classList.remove('chatlog__message--highlighted');
-                }, 2000);
-            }
-        }
-
-        function showSpoiler(event, element) {
-            if (element && element.classList.contains('spoiler--hidden')) {
-                event.preventDefault();
-                element.classList.remove('spoiler--hidden');
-            }
-        }
-    </script>
-</head>
-<body>
-
-{{~ # Preamble ~}}
-<div class="preamble">
-    <div class="preamble__guild-icon-container">
-        <img class="preamble__guild-icon" src="{{ Context.Guild.IconUrl }}" alt="Guild icon">
-    </div>
-    <div class="preamble__entries-container">
-        <div class="preamble__entry">{{ Context.Guild.Name | html.escape }}</div>
-        <div class="preamble__entry">{{ Context.Channel.Category | html.escape }} / {{ Context.Channel.Name | html.escape }}</div>
-
-        {{~ if Context.Channel.Topic ~}}
-        <div class="preamble__entry preamble__entry--small">{{ Context.Channel.Topic | html.escape }}</div>
-        {{~ end ~}}
-
-        {{~ if Context.After || Context.Before ~}}
-        <div class="preamble__entry preamble__entry--small">
-            {{~ if Context.After && Context.Before ~}}
-                Between {{ Context.After | FormatDate | html.escape }} and {{ Context.Before | FormatDate | html.escape }}
-            {{~ else if Context.After ~}}
-                After {{ Context.After | FormatDate | html.escape }}
-            {{~ else if Context.Before ~}}
-                Before {{ Context.Before | FormatDate | html.escape }}
-            {{~ end ~}}
-        </div>
-        {{~ end ~}}
-    </div>
-</div>
-
-{{~ # Log ~}}
-<div class="chatlog">
-    {{~ %SPLIT% ~}}
-</div>
-
-{{~ # Postamble ~}}
-<div class="postamble">
-    <div class="postamble__entry">Exported {{ MessageCount | object.format "N0" }} message(s)</div>
-</div>
-
-</body>
-</html>

DiscordChatExporter.Domain/Exporting/Resources/HtmlMessageGroupTemplate.html

@@ -1,184 +0,0 @@
-<div class="chatlog__message-group">
-    {{~ # Avatar ~}}
-    <div class="chatlog__author-avatar-container">
-        <img class="chatlog__author-avatar" src="{{ MessageGroup.Author.AvatarUrl }}" alt="Avatar">
-    </div>
-    <div class="chatlog__messages">
-        {{~ # Author name and timestamp ~}}
-        {{~ userColor = TryGetUserColor MessageGroup.Author | FormatColorRgb ~}}
-        <span class="chatlog__author-name" title="{{ MessageGroup.Author.FullName | html.escape }}" data-user-id="{{ MessageGroup.Author.Id | html.escape }}" {{ if userColor }} style="color: {{ userColor }}" {{ end }}>{{ (TryGetUserNick MessageGroup.Author ?? MessageGroup.Author.Name) | html.escape }}</span>
-
-        {{~ # Bot tag ~}}
-        {{~ if MessageGroup.Author.IsBot ~}}
-        <span class="chatlog__bot-tag">BOT</span>
-        {{~ end ~}}
-
-        <span class="chatlog__timestamp">{{ MessageGroup.Timestamp | FormatDate | html.escape }}</span>
-
-        {{~ # Messages ~}}
-        {{~ for message in MessageGroup.Messages ~}}
-            <div class="chatlog__message {{ if message.IsPinned }}chatlog__message--pinned{{ end }}" data-message-id="{{ message.Id }}" id="message-{{ message.Id }}">
-            {{~ # Content ~}}
-            {{~ if message.Content ~}}
-                <div class="chatlog__content">
-                    <div class="markdown">
-                        {{- message.Content | FormatMarkdown -}}
-
-                        {{- # Edited timestamp -}}
-                        {{- if message.EditedTimestamp -}}
-                            {{-}}<span class="chatlog__edited-timestamp" title="{{ message.EditedTimestamp | FormatDate | html.escape }}">(edited)</span>{{-}}
-                        {{- end -}}
-                    </div>
-                </div>
-            {{~ end ~}}
-
-            {{~ # Attachments ~}}
-            {{~ for attachment in message.Attachments ~}}
-                <div class="chatlog__attachment">
-                    {{ # Spoiler image }}
-                    {{~ if attachment.IsSpoiler ~}}
-                    <div class="spoiler spoiler--hidden" onclick="showSpoiler(event, this)">
-                        <div class="spoiler-image">
-                            <a href="{{ attachment.Url }}">
-                                <img class="chatlog__attachment-thumbnail" src="{{ attachment.Url }}" alt="Attachment">
-                            </a>
-                        </div>
-                    </div>
-                    {{~ else ~}}
-                    <a href="{{ attachment.Url }}">
-                        {{ # Non-spoiler image }}
-                        {{~ if attachment.IsImage ~}}
-                            <img class="chatlog__attachment-thumbnail" src="{{ attachment.Url }}" alt="Attachment">
-                        {{~ # Non-image ~}}
-                        {{~ else ~}}
-                            Attachment: {{ attachment.FileName }} ({{ attachment.FileSize }})
-                        {{~ end ~}}
-                    </a>
-                    {{~ end ~}}
-                </div>
-            {{~ end ~}}
-
-            {{~ # Embeds ~}}
-            {{~ for embed in message.Embeds ~}}
-            <div class="chatlog__embed">
-                {{~ if embed.Color ~}}
-                <div class="chatlog__embed-color-pill" style="background-color: rgba({{ embed.Color.R }},{{ embed.Color.G }},{{ embed.Color.B }},{{ embed.Color.A }})"></div>
-                {{~ else ~}}
-                <div class="chatlog__embed-color-pill chatlog__embed-color-pill--default"></div>
-                {{~ end ~}}
-                <div class="chatlog__embed-content-container">
-                    <div class="chatlog__embed-content">
-                        <div class="chatlog__embed-text">
-                            {{~ # Author ~}}
-                            {{~ if embed.Author ~}}
-                            <div class="chatlog__embed-author">
-                                {{~ if embed.Author.IconUrl ~}}
-                                <img class="chatlog__embed-author-icon" src="{{ embed.Author.IconUrl }}" alt="Author icon">
-                                {{~ end ~}}
-
-                                {{~ if embed.Author.Name ~}}
-                                <span class="chatlog__embed-author-name">
-                                    {{~ if embed.Author.Url ~}}
-                                    <a class="chatlog__embed-author-name-link" href="{{ embed.Author.Url }}">{{ embed.Author.Name | html.escape }}</a>
-                                    {{~ else ~}}
-                                    {{ embed.Author.Name | html.escape }}
-                                    {{~ end ~}}
-                                </span>
-                                {{~ end ~}}
-                            </div>
-                            {{~ end ~}}
-
-                            {{~ # Title ~}}
-                            {{~ if embed.Title ~}}
-                            <div class="chatlog__embed-title">
-                                {{~ if embed.Url ~}}
-                                <a class="chatlog__embed-title-link" href="{{ embed.Url }}"><div class="markdown">{{ embed.Title | FormatEmbedMarkdown }}</div></a>
-                                {{~ else ~}}
-                                <div class="markdown">{{ embed.Title | FormatEmbedMarkdown }}</div>
-                                {{~ end ~}}
-                            </div>
-                            {{~ end ~}}
-
-                            {{~ # Description ~}}
-                            {{~ if embed.Description ~}}
-                            <div class="chatlog__embed-description"><div class="markdown">{{ embed.Description | FormatEmbedMarkdown }}</div></div>
-                            {{~ end ~}}
-
-                            {{~ # Fields ~}}
-                            {{~ if embed.Fields | array.size > 0 ~}}
-                            <div class="chatlog__embed-fields">
-                                {{~ for field in embed.Fields ~}}
-                                <div class="chatlog__embed-field {{ if field.IsInline }} chatlog__embed-field--inline {{ end }}">
-                                    {{~ if field.Name ~}}
-                                    <div class="chatlog__embed-field-name"><div class="markdown">{{ field.Name | FormatEmbedMarkdown }}</div></div>
-                                    {{~ end ~}}
-                                    {{~ if field.Value ~}}
-                                    <div class="chatlog__embed-field-value"><div class="markdown">{{ field.Value | FormatEmbedMarkdown }}</div></div>
-                                    {{~ end ~}}
-                                </div>
-                                {{~ end ~}}
-                            </div>
-                            {{~ end ~}}
-                        </div>
-
-                        {{~ # Thumbnail ~}}
-                        {{~ if embed.Thumbnail ~}}
-                        <div class="chatlog__embed-thumbnail-container">
-                            <a class="chatlog__embed-thumbnail-link" href="{{ embed.Thumbnail.Url }}">
-                                <img class="chatlog__embed-thumbnail" src="{{ embed.Thumbnail.Url }}" alt="Thumbnail">
-                            </a>
-                        </div>
-                        {{~ end ~}}
-                    </div>
-
-                    {{~ # Image ~}}
-                    {{~ if embed.Image ~}}
-                    <div class="chatlog__embed-image-container">
-                        <a class="chatlog__embed-image-link" href="{{ embed.Image.Url }}">
-                            <img class="chatlog__embed-image" src="{{ embed.Image.Url }}" alt="Image">
-                        </a>
-                    </div>
-                    {{~ end ~}}
-
-                    {{~ # Footer ~}}
-                    {{~ if embed.Footer || embed.Timestamp ~}}
-                    <div class="chatlog__embed-footer">
-                        {{~ if embed.Footer ~}}
-                        {{~ if embed.Footer.Text && embed.Footer.IconUrl ~}}
-                        <img class="chatlog__embed-footer-icon" src="{{ embed.Footer.IconUrl }}" alt="Footer icon">
-                        {{~ end ~}}
-                        {{~ end ~}}
-
-                        <span class="chatlog__embed-footer-text">
-                            {{~ if embed.Footer ~}}
-                            {{~ if embed.Footer.Text ~}}
-                            {{ embed.Footer.Text | html.escape }}
-                            {{ if embed.Timestamp }} • {{ end }}
-                            {{~ end ~}}
-                            {{~ end ~}}
-
-                            {{~ if embed.Timestamp ~}}
-                            {{ embed.Timestamp | FormatDate | html.escape }}
-                            {{~ end ~}}
-                        </span>
-                    </div>
-                    {{~ end ~}}
-                </div>
-            </div>
-            {{~ end ~}}
-
-            {{~ # Reactions ~}}
-            {{~ if message.Reactions | array.size > 0 ~}}
-                <div class="chatlog__reactions">
-                    {{~ for reaction in message.Reactions ~}}
-                        <div class="chatlog__reaction">
-                            <img class="emoji emoji--small" alt="{{ reaction.Emoji.Name }}" title="{{ reaction.Emoji.Name }}" src="{{ reaction.Emoji.ImageUrl }}">
-                            <span class="chatlog__reaction-count">{{ reaction.Count }}</span>
-                        </div>
-                    {{~ end ~}}
-                </div>
-            {{~ end ~}}
-            </div>
-        {{~ end ~}}
-    </div>
-</div>

DiscordChatExporter.Domain/Exporting/Writers/CsvMessageWriter.cs

@@ -1,11 +1,10 @@
-using System.IO;
+using System.Collections.Generic;
-using System.Linq;
+using System.IO;
 using System.Text;
 using System.Threading.Tasks;
 using DiscordChatExporter.Domain.Discord.Models;
 using DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
-using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Domain.Exporting.Writers
 {
@@ -22,22 +21,68 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
         private string FormatMarkdown(string? markdown) =>
             PlainTextMarkdownVisitor.Format(Context, markdown ?? "");
 
-        public override async Task WritePreambleAsync() =>
+        public override async ValueTask WritePreambleAsync() =>
             await _writer.WriteLineAsync("AuthorID,Author,Date,Content,Attachments,Reactions");
 
-        public override async Task WriteMessageAsync(Message message)
+        private async ValueTask WriteAttachmentsAsync(IReadOnlyList<Attachment> attachments)
         {
             var buffer = new StringBuilder();
 
+            foreach (var attachment in attachments)
+            {
                 buffer
-                .Append(CsvEncode(message.Author.Id)).Append(',')
+                    .AppendIfNotEmpty(',')
-                .Append(CsvEncode(message.Author.FullName)).Append(',')
+                    .Append(await Context.ResolveMediaUrlAsync(attachment.Url));
-                .Append(CsvEncode(message.Timestamp.ToLocalString(Context.DateFormat))).Append(',')
+            }
-                .Append(CsvEncode(FormatMarkdown(message.Content))).Append(',')
-                .Append(CsvEncode(message.Attachments.Select(a => a.Url).JoinToString(","))).Append(',')
-                .Append(CsvEncode(message.Reactions.Select(r => $"{r.Emoji.Name} ({r.Count})").JoinToString(",")));
 
-            await _writer.WriteLineAsync(buffer.ToString());
+            await _writer.WriteAsync(CsvEncode(buffer.ToString()));
+        }
+
+        private async ValueTask WriteReactionsAsync(IReadOnlyList<Reaction> reactions)
+        {
+            var buffer = new StringBuilder();
+
+            foreach (var reaction in reactions)
+            {
+                buffer
+                    .AppendIfNotEmpty(',')
+                    .Append(reaction.Emoji.Name)
+                    .Append(' ')
+                    .Append('(')
+                    .Append(reaction.Count)
+                    .Append(')');
+            }
+
+            await _writer.WriteAsync(CsvEncode(buffer.ToString()));
+        }
+
+        public override async ValueTask WriteMessageAsync(Message message)
+        {
+            // Author ID
+            await _writer.WriteAsync(CsvEncode(message.Author.Id));
+            await _writer.WriteAsync(',');
+
+            // Author name
+            await _writer.WriteAsync(CsvEncode(message.Author.FullName));
+            await _writer.WriteAsync(',');
+
+            // Message timestamp
+            await _writer.WriteAsync(CsvEncode(Context.FormatDate(message.Timestamp)));
+            await _writer.WriteAsync(',');
+
+            // Message content
+            await _writer.WriteAsync(CsvEncode(FormatMarkdown(message.Content)));
+            await _writer.WriteAsync(',');
+
+            // Attachments
+            await WriteAttachmentsAsync(message.Attachments);
+            await _writer.WriteAsync(',');
+
+            // Reactions
+            await WriteReactionsAsync(message.Reactions);
+
+            // Finish row
+            await _writer.WriteLineAsync();
         }
 
         public override async ValueTask DisposeAsync()

DiscordChatExporter.Domain/Exporting/Writers/Html/Core.css

@@ -2,31 +2,31 @@
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/6c6374bad0b0b6d204d8d6dc4a18d820.woff);
+    src: url(https://discord.com/assets/6c6374bad0b0b6d204d8d6dc4a18d820.woff);
     font-weight: 300;
 }
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/e8acd7d9bf6207f99350ca9f9e23b168.woff);
+    src: url(https://discord.com/assets/e8acd7d9bf6207f99350ca9f9e23b168.woff);
     font-weight: 400;
 }
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/3bdef1251a424500c1b3a78dea9b7e57.woff);
+    src: url(https://discord.com/assets/3bdef1251a424500c1b3a78dea9b7e57.woff);
     font-weight: 500;
 }
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/be0060dafb7a0e31d2a1ca17c0708636.woff);
+    src: url(https://discord.com/assets/be0060dafb7a0e31d2a1ca17c0708636.woff);
     font-weight: 600;
 }
 
 @font-face {
     font-family: Whitney;
-    src: url(https://discordapp.com/assets/8e12fb4f14d9c4592eb8ec9f22337b04.woff);
+    src: url(https://discord.com/assets/8e12fb4f14d9c4592eb8ec9f22337b04.woff);
     font-weight: 700;
 }
 

DiscordChatExporter.Domain/Exporting/Writers/Html/LayoutTemplateContext.cs

@@ -0,0 +1,18 @@
+namespace DiscordChatExporter.Domain.Exporting.Writers.Html
+{
+    internal class LayoutTemplateContext
+    {
+        public ExportContext ExportContext { get; }
+
+        public string ThemeName { get; }
+
+        public long MessageCount { get; }
+
+        public LayoutTemplateContext(ExportContext exportContext, string themeName, long messageCount)
+        {
+            ExportContext = exportContext;
+            ThemeName = themeName;
+            MessageCount = messageCount;
+        }
+    }
+}

DiscordChatExporter.Domain/Exporting/Writers/Html/MessageGroup.cs

@@ -1,8 +1,9 @@
 using System;
 using System.Collections.Generic;
+using System.Linq;
 using DiscordChatExporter.Domain.Discord.Models;
 
-namespace DiscordChatExporter.Domain.Exporting
+namespace DiscordChatExporter.Domain.Exporting.Writers.Html
 {
     // Used for grouping contiguous messages in HTML export
     internal partial class MessageGroup
@@ -23,9 +24,20 @@ namespace DiscordChatExporter.Domain.Exporting
 
     internal partial class MessageGroup
     {
-        public static bool CanGroup(Message message1, Message message2) =>
+        public static bool CanJoin(Message message1, Message message2) =>
             string.Equals(message1.Author.Id, message2.Author.Id, StringComparison.Ordinal) &&
             string.Equals(message1.Author.FullName, message2.Author.FullName, StringComparison.Ordinal) &&
             (message2.Timestamp - message1.Timestamp).Duration().TotalMinutes <= 7;
+
+        public static MessageGroup Join(IReadOnlyList<Message> messages)
+        {
+            var first = messages.First();
+
+            return new MessageGroup(
+                first.Author,
+                first.Timestamp,
+                messages
+            );
+        }
     }
 }

DiscordChatExporter.Domain/Exporting/Writers/Html/MessageGroupTemplate.cshtml

@@ -0,0 +1,230 @@
+@using System
+@using System.Linq
+@using System.Threading.Tasks
+@inherits MiniRazor.MiniRazorTemplateBase<DiscordChatExporter.Domain.Exporting.Writers.Html.MessageGroupTemplateContext>
+
+@{
+    string FormatDate(DateTimeOffset date) => Model.ExportContext.FormatDate(date);
+
+    string FormatMarkdown(string markdown) => Model.FormatMarkdown(markdown);
+
+    string FormatEmbedMarkdown(string markdown) => Model.FormatMarkdown(markdown, false);
+
+    ValueTask<string> ResolveUrlAsync(string url) => Model.ExportContext.ResolveMediaUrlAsync(url);
+
+    var userMember = Model.ExportContext.TryGetMember(Model.MessageGroup.Author.Id);
+    var userColor = Model.ExportContext.TryGetUserColor(Model.MessageGroup.Author.Id);
+    var userNick = (Model.MessageGroup.Author.IsBot ? Model.MessageGroup.Author.Name : (userMember?.Nick ?? Model.MessageGroup.Author.Name));
+
+    var userColorStyle = userColor != null
+        ? $"color: rgb({userColor?.R},{userColor?.G},{userColor?.B})"
+        : null;
+}
+
+<div class="chatlog__message-group">
+    <div class="chatlog__author-avatar-container">
+        <img class="chatlog__author-avatar" src="@await ResolveUrlAsync(Model.MessageGroup.Author.AvatarUrl)" alt="Avatar">
+    </div>
+    <div class="chatlog__messages">
+        <span class="chatlog__author-name" title="@Model.MessageGroup.Author.FullName" data-user-id="@Model.MessageGroup.Author.Id" style="@userColorStyle">@userNick</span>
+
+        @if (Model.MessageGroup.Author.IsBot)
+        {
+            <span class="chatlog__bot-tag">BOT</span>
+        }
+
+        <span class="chatlog__timestamp">@FormatDate(Model.MessageGroup.Timestamp)</span>
+
+        @foreach (var message in Model.MessageGroup.Messages)
+        {
+            var isPinnedStyle = message.IsPinned ? "chatlog__message--pinned" : null;
+
+            <div class="chatlog__message @isPinnedStyle" data-message-id="@message.Id" id="message-@message.Id">
+                <div class="chatlog__content">
+                    <div class="markdown">@Raw(FormatMarkdown(message.Content)) @if (message.EditedTimestamp != null) {<span class="chatlog__edited-timestamp" title="@FormatDate(message.EditedTimestamp.Value)">(edited)</span>}</div>
+                </div>
+
+                @foreach (var attachment in message.Attachments)
+                {
+                    <div class="chatlog__attachment">
+                        @if (attachment.IsSpoiler)
+                        {
+                            <div class="spoiler spoiler--hidden" onclick="showSpoiler(event, this)">
+                                <div class="spoiler-image">
+                                    <a href="@await ResolveUrlAsync(attachment.Url)">
+                                        <img class="chatlog__attachment-thumbnail" src="@await ResolveUrlAsync(attachment.Url)" alt="Attachment">
+                                    </a>
+                                </div>
+                            </div>
+                        }
+                        else
+                        {
+                            <a href="@await ResolveUrlAsync(attachment.Url)">
+                                @if (attachment.IsImage)
+                                {
+                                    <img class="chatlog__attachment-thumbnail" src="@await ResolveUrlAsync(attachment.Url)" alt="Attachment">
+                                }
+                                else
+                                {
+                                    @($"Attachment: {attachment.FileName} ({attachment.FileSize})")
+                                }
+                            </a>
+                        }
+                    </div>
+                }
+
+                @foreach (var embed in message.Embeds)
+                {
+                    <div class="chatlog__embed">
+                        @if (embed.Color != null)
+                        {
+                            var embedColorStyle = $"background-color: rgba({embed.Color?.R},{embed.Color?.G},{embed.Color?.B},{embed.Color?.A})";
+                            <div class="chatlog__embed-color-pill" style="@embedColorStyle"></div>
+                        }
+                        else
+                        {
+                            <div class="chatlog__embed-color-pill chatlog__embed-color-pill--default"></div>
+                        }
+
+                        <div class="chatlog__embed-content-container">
+                            <div class="chatlog__embed-content">
+                                <div class="chatlog__embed-text">
+                                    @if (embed.Author != null)
+                                    {
+                                        <div class="chatlog__embed-author">
+                                            @if (!string.IsNullOrWhiteSpace(embed.Author.IconUrl))
+                                            {
+                                                <img class="chatlog__embed-author-icon" src="@await ResolveUrlAsync(embed.Author.IconUrl)" alt="Author icon">
+                                            }
+
+                                            @if (!string.IsNullOrWhiteSpace(embed.Author.Name))
+                                            {
+                                                <span class="chatlog__embed-author-name">
+                                                    @if (!string.IsNullOrWhiteSpace(embed.Author.Url))
+                                                    {
+                                                        <a class="chatlog__embed-author-name-link" href="@embed.Author.Url">@embed.Author.Name</a>
+                                                    }
+                                                    else
+                                                    {
+                                                        @embed.Author.Name
+                                                    }
+                                                </span>
+                                            }
+                                        </div>
+                                    }
+
+                                    @if (!string.IsNullOrWhiteSpace(embed.Title))
+                                    {
+                                        <div class="chatlog__embed-title">
+                                            @if (!string.IsNullOrWhiteSpace(embed.Url))
+                                            {
+                                                <a class="chatlog__embed-title-link" href="@embed.Url">
+                                                    <div class="markdown">@Raw(FormatEmbedMarkdown(embed.Title))</div>
+                                                </a>
+                                            }
+                                            else
+                                            {
+                                                <div class="markdown">@Raw(FormatEmbedMarkdown(embed.Title))</div>
+                                            }
+                                        </div>
+                                    }
+
+                                    @if (!string.IsNullOrWhiteSpace(embed.Description))
+                                    {
+                                        <div class="chatlog__embed-description">
+                                            <div class="markdown">@Raw(FormatEmbedMarkdown(embed.Description))</div>
+                                        </div>
+                                    }
+
+                                    @if (embed.Fields.Any())
+                                    {
+                                        <div class="chatlog__embed-fields">
+                                            @foreach (var field in embed.Fields)
+                                            {
+                                                var isInlineStyle = field.IsInline ? "chatlog__embed-field--inline" : null;
+
+                                                <div class="chatlog__embed-field @isInlineStyle">
+                                                    @if (!string.IsNullOrWhiteSpace(field.Name))
+                                                    {
+                                                        <div class="chatlog__embed-field-name">
+                                                            <div class="markdown">@Raw(FormatEmbedMarkdown(field.Name))</div>
+                                                        </div>
+                                                    }
+
+                                                    @if (!string.IsNullOrWhiteSpace(field.Value))
+                                                    {
+                                                        <div class="chatlog__embed-field-value">
+                                                            <div class="markdown">@Raw(FormatEmbedMarkdown(field.Value))</div>
+                                                        </div>
+                                                    }
+                                                </div>
+                                            }
+                                        </div>
+                                    }
+                                </div>
+
+                                @if (embed.Thumbnail != null)
+                                {
+                                    <div class="chatlog__embed-thumbnail-container">
+                                        <a class="chatlog__embed-thumbnail-link" href="@await ResolveUrlAsync(embed.Thumbnail.Url)">
+                                            <img class="chatlog__embed-thumbnail" src="@await ResolveUrlAsync(embed.Thumbnail.Url)" alt="Thumbnail">
+                                        </a>
+                                    </div>
+                                }
+                            </div>
+
+                            @if (embed.Image != null)
+                            {
+                                <div class="chatlog__embed-image-container">
+                                    <a class="chatlog__embed-image-link" href="@await ResolveUrlAsync(embed.Image.Url)">
+                                        <img class="chatlog__embed-image" src="@await ResolveUrlAsync(embed.Image.Url)" alt="Image">
+                                    </a>
+                                </div>
+                            }
+
+                            @if (embed.Footer != null || embed.Timestamp != null)
+                            {
+                                <div class="chatlog__embed-footer">
+                                    @if (!string.IsNullOrWhiteSpace(embed.Footer?.IconUrl))
+                                    {
+                                        <img class="chatlog__embed-footer-icon" src="@await ResolveUrlAsync(embed.Footer.IconUrl)" alt="Footer icon">
+                                    }
+
+                                        <span class="chatlog__embed-footer-text">
+                                            @if (!string.IsNullOrWhiteSpace(embed.Footer?.Text))
+                                            {
+                                                @embed.Footer.Text
+                                            }
+
+                                            @if (!string.IsNullOrWhiteSpace(embed.Footer?.Text) && embed.Timestamp != null)
+                                            {
+                                                @(" • ")
+                                            }
+
+                                            @if (embed.Timestamp != null)
+                                            {
+                                                @FormatDate(embed.Timestamp.Value)
+                                            }
+                                        </span>
+                                </div>
+                            }
+                        </div>
+                    </div>
+                }
+
+                @if (message.Reactions.Any())
+                {
+                    <div class="chatlog__reactions">
+                        @foreach (var reaction in message.Reactions)
+                        {
+                            <div class="chatlog__reaction">
+                                <img class="emoji emoji--small" alt="@reaction.Emoji.Name" title="@reaction.Emoji.Name" src="@await ResolveUrlAsync(reaction.Emoji.ImageUrl)">
+                                <span class="chatlog__reaction-count">@reaction.Count</span>
+                            </div>
+                        }
+                    </div>
+                }
+            </div>
+        }
+    </div>
+</div>

DiscordChatExporter.Domain/Exporting/Writers/Html/MessageGroupTemplateContext.cs

@@ -0,0 +1,20 @@
+using DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors;
+
+namespace DiscordChatExporter.Domain.Exporting.Writers.Html
+{
+    internal class MessageGroupTemplateContext
+    {
+        public ExportContext ExportContext { get; }
+
+        public MessageGroup MessageGroup { get; }
+
+        public MessageGroupTemplateContext(ExportContext exportContext, MessageGroup messageGroup)
+        {
+            ExportContext = exportContext;
+            MessageGroup = messageGroup;
+        }
+
+        public string FormatMarkdown(string? markdown, bool isJumboAllowed = true) =>
+            HtmlMarkdownVisitor.Format(ExportContext, markdown ?? "", isJumboAllowed);
+    }
+}

DiscordChatExporter.Domain/Exporting/Writers/Html/PostambleTemplate.cshtml

@@ -0,0 +1,10 @@
+@inherits MiniRazor.MiniRazorTemplateBase<DiscordChatExporter.Domain.Exporting.Writers.Html.LayoutTemplateContext>
+
+</div>
+
+<div class="postamble">
+    <div class="postamble__entry">Exported @Model.MessageCount.ToString("N0") message(s)</div>
+</div>
+
+</body>
+</html>

DiscordChatExporter.Domain/Exporting/Writers/Html/PreambleTemplate.cshtml

@@ -0,0 +1,100 @@
+@using System
+@using System.Threading.Tasks
+@using Tyrrrz.Extensions
+@inherits MiniRazor.MiniRazorTemplateBase<DiscordChatExporter.Domain.Exporting.Writers.Html.LayoutTemplateContext>
+
+@{
+    string FormatDate(DateTimeOffset date) => Model.ExportContext.FormatDate(date);
+
+    ValueTask<string> ResolveUrlAsync(string url) => Model.ExportContext.ResolveMediaUrlAsync(url);
+
+    string GetStyleSheet(string name) => Model.GetType().Assembly.GetManifestResourceString($"DiscordChatExporter.Domain.Exporting.Writers.Html.{name}.css");
+}
+
+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+    <title>@Model.ExportContext.Request.Guild.Name - @Model.ExportContext.Request.Channel.Name</title>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width">
+
+    <style>
+        @Raw(GetStyleSheet("Core"))
+    </style>
+    <style>
+        @Raw(GetStyleSheet(Model.ThemeName))
+    </style>
+
+    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.6/styles/solarized-@(Model.ThemeName.ToLowerInvariant()).min.css">
+    <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/9.15.6/highlight.min.js"></script>
+    <script>
+        document.addEventListener('DOMContentLoaded', () => {
+            document.querySelectorAll('.pre--multiline').forEach(block => hljs.highlightBlock(block));
+        });
+    </script>
+
+    <script>
+        function scrollToMessage(event, id) {
+            var element = document.getElementById('message-' + id);
+
+            if (element) {
+                event.preventDefault();
+
+                element.classList.add('chatlog__message--highlighted');
+
+                window.scrollTo({
+                    top: element.getBoundingClientRect().top - document.body.getBoundingClientRect().top - (window.innerHeight / 2),
+                    behavior: 'smooth'
+                });
+
+                window.setTimeout(function() {
+                    element.classList.remove('chatlog__message--highlighted');
+                }, 2000);
+            }
+        }
+
+        function showSpoiler(event, element) {
+            if (element && element.classList.contains('spoiler--hidden')) {
+                event.preventDefault();
+                element.classList.remove('spoiler--hidden');
+            }
+        }
+    </script>
+</head>
+<body>
+
+<div class="preamble">
+    <div class="preamble__guild-icon-container">
+        <img class="preamble__guild-icon" src="@await ResolveUrlAsync(Model.ExportContext.Request.Guild.IconUrl)" alt="Guild icon">
+    </div>
+    <div class="preamble__entries-container">
+        <div class="preamble__entry">@Model.ExportContext.Request.Guild.Name</div>
+        <div class="preamble__entry">@Model.ExportContext.Request.Channel.Category / @Model.ExportContext.Request.Channel.Name</div>
+
+        @if (!string.IsNullOrWhiteSpace(Model.ExportContext.Request.Channel.Topic))
+        {
+            <div class="preamble__entry preamble__entry--small">@Model.ExportContext.Request.Channel.Topic</div>
+        }
+
+        @if (Model.ExportContext.Request.After != null || Model.ExportContext.Request.Before != null)
+        {
+            <div class="preamble__entry preamble__entry--small">
+            @if (Model.ExportContext.Request.After != null && Model.ExportContext.Request.Before != null)
+            {
+                @($"Between {FormatDate(Model.ExportContext.Request.After.Value)} and {FormatDate(Model.ExportContext.Request.Before.Value)}")
+            }
+            else if (Model.ExportContext.Request.After != null)
+            {
+                @($"After {FormatDate(Model.ExportContext.Request.After.Value)}")
+            }
+            else if (Model.ExportContext.Request.Before != null)
+            {
+                @($"Before {FormatDate(Model.ExportContext.Request.Before.Value)}")
+            }
+            </div>
+        }
+    </div>
+</div>
+
+<div class="chatlog">

DiscordChatExporter.Domain/Exporting/Writers/Html/TemplateBundle.cs

@@ -0,0 +1,65 @@
+using System.Runtime.CompilerServices;
+using System.Threading.Tasks;
+using MiniRazor;
+using Tyrrrz.Extensions;
+
+[assembly: InternalsVisibleTo(DiscordChatExporter.Domain.Exporting.Writers.Html.TemplateBundle.PreambleTemplateAssemblyName)]
+[assembly: InternalsVisibleTo(DiscordChatExporter.Domain.Exporting.Writers.Html.TemplateBundle.MessageGroupTemplateAssemblyName)]
+[assembly: InternalsVisibleTo(DiscordChatExporter.Domain.Exporting.Writers.Html.TemplateBundle.PostambleTemplateAssemblyName)]
+
+namespace DiscordChatExporter.Domain.Exporting.Writers.Html
+{
+    internal partial class TemplateBundle
+    {
+        public const string PreambleTemplateAssemblyName = "RazorAssembly_Preamble";
+        public const string MessageGroupTemplateAssemblyName = "RazorAssembly_MessageGroup";
+        public const string PostambleTemplateAssemblyName = "RazorAssembly_Postamble";
+
+        public MiniRazorTemplateDescriptor PreambleTemplate { get; }
+
+        public MiniRazorTemplateDescriptor MessageGroupTemplate { get; }
+
+        public MiniRazorTemplateDescriptor PostambleTemplate { get; }
+
+        public TemplateBundle(
+            MiniRazorTemplateDescriptor preambleTemplate,
+            MiniRazorTemplateDescriptor messageGroupTemplate,
+            MiniRazorTemplateDescriptor postambleTemplate)
+        {
+            PreambleTemplate = preambleTemplate;
+            MessageGroupTemplate = messageGroupTemplate;
+            PostambleTemplate = postambleTemplate;
+        }
+    }
+
+    internal partial class TemplateBundle
+    {
+        private static TemplateBundle? _lastBundle;
+
+        // This is very CPU-heavy
+        private static async ValueTask<TemplateBundle> CompileAsync() => await Task.Run(() =>
+        {
+            var ns = typeof(TemplateBundle).Namespace!;
+
+            var preambleTemplateSource = typeof(HtmlMessageWriter).Assembly
+                .GetManifestResourceString($"{ns}.PreambleTemplate.cshtml");
+
+            var messageGroupTemplateSource = typeof(HtmlMessageWriter).Assembly
+                .GetManifestResourceString($"{ns}.MessageGroupTemplate.cshtml");
+
+            var postambleTemplateSource = typeof(HtmlMessageWriter).Assembly
+                .GetManifestResourceString($"{ns}.PostambleTemplate.cshtml");
+
+            var engine = new MiniRazorTemplateEngine();
+
+            var preambleTemplate = engine.Compile(preambleTemplateSource, PreambleTemplateAssemblyName, ns);
+            var messageGroupTemplate = engine.Compile(messageGroupTemplateSource, MessageGroupTemplateAssemblyName, ns);
+            var postambleTemplate = engine.Compile(postambleTemplateSource, PostambleTemplateAssemblyName, ns);
+
+            return new TemplateBundle(preambleTemplate, messageGroupTemplate, postambleTemplate);
+        });
+
+        public static async ValueTask<TemplateBundle> ResolveAsync() =>
+            _lastBundle ??= await CompileAsync();
+    }
+}

DiscordChatExporter.Domain/Exporting/Writers/HtmlMessageWriter.cs

@@ -1,28 +1,18 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
-using System.Drawing;
 using System.IO;
 using System.Linq;
-using System.Reflection;
 using System.Threading.Tasks;
 using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors;
+using DiscordChatExporter.Domain.Exporting.Writers.Html;
-using DiscordChatExporter.Domain.Internal;
-using Scriban;
-using Scriban.Runtime;
-using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Domain.Exporting.Writers
 {
-    internal partial class HtmlMessageWriter : MessageWriter
+    internal class HtmlMessageWriter : MessageWriter
     {
         private readonly TextWriter _writer;
         private readonly string _themeName;
-        private readonly List<Message> _messageGroupBuffer = new List<Message>();
 
-        private readonly Template _preambleTemplate;
+        private readonly List<Message> _messageGroupBuffer = new List<Message>();
-        private readonly Template _messageGroupTemplate;
-        private readonly Template _postambleTemplate;
 
         private long _messageCount;
 
@@ -31,103 +21,39 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
         {
             _writer = new StreamWriter(stream);
             _themeName = themeName;
-
-            _preambleTemplate = Template.Parse(GetPreambleTemplateCode());
-            _messageGroupTemplate = Template.Parse(GetMessageGroupTemplateCode());
-            _postambleTemplate = Template.Parse(GetPostambleTemplateCode());
         }
 
-        private MessageGroup GetCurrentMessageGroup()
+        public override async ValueTask WritePreambleAsync()
         {
-            var firstMessage = _messageGroupBuffer.First();
+            var templateContext = new LayoutTemplateContext(Context, _themeName, _messageCount);
-            return new MessageGroup(firstMessage.Author, firstMessage.Timestamp, _messageGroupBuffer);
+            var templateBundle = await TemplateBundle.ResolveAsync();
+
+            await _writer.WriteLineAsync(
+                await templateBundle.PreambleTemplate.RenderAsync(templateContext)
+            );
         }
 
-        private TemplateContext CreateTemplateContext(IReadOnlyDictionary<string, object>? constants = null)
+        private async ValueTask WriteMessageGroupAsync(MessageGroup messageGroup)
         {
-            // Template context
+            var templateContext = new MessageGroupTemplateContext(Context, messageGroup);
-            var templateContext = new TemplateContext
+            var templateBundle = await TemplateBundle.ResolveAsync();
-            {
-                MemberRenamer = m => m.Name,
-                MemberFilter = m => true,
-                LoopLimit = int.MaxValue,
-                StrictVariables = true
-            };
 
-            // Model
+            await _writer.WriteLineAsync(
-            var scriptObject = new ScriptObject();
+                await templateBundle.MessageGroupTemplate.RenderAsync(templateContext)
-
+            );
-            // Constants
-            scriptObject.SetValue("Context", Context, true);
-            scriptObject.SetValue("CoreStyleSheet", GetCoreStyleSheetCode(), true);
-            scriptObject.SetValue("ThemeStyleSheet", GetThemeStyleSheetCode(_themeName), true);
-            scriptObject.SetValue("HighlightJsStyleName", $"solarized-{_themeName.ToLowerInvariant()}", true);
-
-            // Additional constants
-            if (constants != null)
-            {
-                foreach (var (member, value) in constants)
-                    scriptObject.SetValue(member, value, true);
         }
 
-            // Functions
+        public override async ValueTask WriteMessageAsync(Message message)
-            scriptObject.Import("FormatDate",
-                new Func<DateTimeOffset, string>(d => d.ToLocalString(Context.DateFormat)));
-
-            scriptObject.Import("FormatColorRgb",
-                new Func<Color?, string?>(c => c != null ? $"rgb({c?.R}, {c?.G}, {c?.B})" : null));
-
-            scriptObject.Import("TryGetUserColor",
-                new Func<User, Color?>(Context.TryGetUserColor));
-
-            scriptObject.Import("TryGetUserNick",
-                new Func<User, string?>(u => Context.TryGetUserMember(u)?.Nick));
-
-            scriptObject.Import("FormatMarkdown",
-                new Func<string?, string>(m => FormatMarkdown(m)));
-
-            scriptObject.Import("FormatEmbedMarkdown",
-                new Func<string?, string>(m => FormatMarkdown(m, false)));
-
-            // Push model
-            templateContext.PushGlobal(scriptObject);
-
-            // Push output
-            templateContext.PushOutput(new TextWriterOutput(_writer));
-
-            return templateContext;
-        }
-
-        private string FormatMarkdown(string? markdown, bool isJumboAllowed = true) =>
-            HtmlMarkdownVisitor.Format(Context, markdown ?? "", isJumboAllowed);
-
-        private async Task RenderCurrentMessageGroupAsync()
-        {
-            var templateContext = CreateTemplateContext(new Dictionary<string, object>
-            {
-                ["MessageGroup"] = GetCurrentMessageGroup()
-            });
-
-            await templateContext.EvaluateAsync(_messageGroupTemplate.Page);
-        }
-
-        public override async Task WritePreambleAsync()
-        {
-            var templateContext = CreateTemplateContext();
-            await templateContext.EvaluateAsync(_preambleTemplate.Page);
-        }
-
-        public override async Task WriteMessageAsync(Message message)
         {
             // If message group is empty or the given message can be grouped, buffer the given message
-            if (!_messageGroupBuffer.Any() || MessageGroup.CanGroup(_messageGroupBuffer.Last(), message))
+            if (!_messageGroupBuffer.Any() || MessageGroup.CanJoin(_messageGroupBuffer.Last(), message))
             {
                 _messageGroupBuffer.Add(message);
             }
             // Otherwise, flush the group and render messages
             else
             {
-                await RenderCurrentMessageGroupAsync();
+                await WriteMessageGroupAsync(MessageGroup.Join(_messageGroupBuffer));
 
                 _messageGroupBuffer.Clear();
                 _messageGroupBuffer.Add(message);
@@ -137,18 +63,18 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             _messageCount++;
         }
 
-        public override async Task WritePostambleAsync()
+        public override async ValueTask WritePostambleAsync()
         {
             // Flush current message group
             if (_messageGroupBuffer.Any())
-                await RenderCurrentMessageGroupAsync();
+                await WriteMessageGroupAsync(MessageGroup.Join(_messageGroupBuffer));
 
-            var templateContext = CreateTemplateContext(new Dictionary<string, object>
+            var templateContext = new LayoutTemplateContext(Context, _themeName, _messageCount);
-            {
+            var templateBundle = await TemplateBundle.ResolveAsync();
-                ["MessageCount"] = _messageCount
-            });
 
-            await templateContext.EvaluateAsync(_postambleTemplate.Page);
+            await _writer.WriteLineAsync(
+                await templateBundle.PostambleTemplate.RenderAsync(templateContext)
+            );
         }
 
         public override async ValueTask DisposeAsync()
@@ -157,32 +83,4 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             await base.DisposeAsync();
         }
     }
-
-    internal partial class HtmlMessageWriter
-    {
-        private static readonly Assembly ResourcesAssembly = typeof(HtmlMessageWriter).Assembly;
-        private static readonly string ResourcesNamespace = $"{ResourcesAssembly.GetName().Name}.Exporting.Resources";
-
-        private static string GetCoreStyleSheetCode() =>
-            ResourcesAssembly
-                .GetManifestResourceString($"{ResourcesNamespace}.HtmlCore.css");
-
-        private static string GetThemeStyleSheetCode(string themeName) =>
-            ResourcesAssembly
-                .GetManifestResourceString($"{ResourcesNamespace}.Html{themeName}.css");
-
-        private static string GetPreambleTemplateCode() =>
-            ResourcesAssembly
-                .GetManifestResourceString($"{ResourcesNamespace}.HtmlLayoutTemplate.html")
-                .SubstringUntil("{{~ %SPLIT% ~}}");
-
-        private static string GetMessageGroupTemplateCode() =>
-            ResourcesAssembly
-                .GetManifestResourceString($"{ResourcesNamespace}.HtmlMessageGroupTemplate.html");
-
-        private static string GetPostambleTemplateCode() =>
-            ResourcesAssembly
-                .GetManifestResourceString($"{ResourcesNamespace}.HtmlLayoutTemplate.html")
-                .SubstringAfter("{{~ %SPLIT% ~}}");
-    }
 }

DiscordChatExporter.Domain/Exporting/Writers/JsonMessageWriter.cs

@@ -3,7 +3,7 @@ using System.Text.Json;
 using System.Threading.Tasks;
 using DiscordChatExporter.Domain.Discord.Models;
 using DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors;
-using DiscordChatExporter.Domain.Internal;
+using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Exporting.Writers
 {
@@ -25,62 +25,75 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
         private string FormatMarkdown(string? markdown) =>
             PlainTextMarkdownVisitor.Format(Context, markdown ?? "");
 
-        private void WriteAttachment(Attachment attachment)
+        private async ValueTask WriteAttachmentAsync(Attachment attachment)
         {
             _writer.WriteStartObject();
 
             _writer.WriteString("id", attachment.Id);
-            _writer.WriteString("url", attachment.Url);
+            _writer.WriteString("url", await Context.ResolveMediaUrlAsync(attachment.Url));
             _writer.WriteString("fileName", attachment.FileName);
             _writer.WriteNumber("fileSizeBytes", attachment.FileSize.TotalBytes);
 
             _writer.WriteEndObject();
+            await _writer.FlushAsync();
         }
 
-        private void WriteEmbedAuthor(EmbedAuthor embedAuthor)
+        private async ValueTask WriteEmbedAuthorAsync(EmbedAuthor embedAuthor)
         {
             _writer.WriteStartObject("author");
 
             _writer.WriteString("name", embedAuthor.Name);
             _writer.WriteString("url", embedAuthor.Url);
-            _writer.WriteString("iconUrl", embedAuthor.IconUrl);
+
+            if (!string.IsNullOrWhiteSpace(embedAuthor.IconUrl))
+                _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(embedAuthor.IconUrl));
 
             _writer.WriteEndObject();
+            await _writer.FlushAsync();
         }
 
-        private void WriteEmbedThumbnail(EmbedImage embedThumbnail)
+        private async ValueTask WriteEmbedThumbnailAsync(EmbedImage embedThumbnail)
         {
             _writer.WriteStartObject("thumbnail");
 
-            _writer.WriteString("url", embedThumbnail.Url);
+            if (!string.IsNullOrWhiteSpace(embedThumbnail.Url))
+                _writer.WriteString("url", await Context.ResolveMediaUrlAsync(embedThumbnail.Url));
+
             _writer.WriteNumber("width", embedThumbnail.Width);
             _writer.WriteNumber("height", embedThumbnail.Height);
 
             _writer.WriteEndObject();
+            await _writer.FlushAsync();
         }
 
-        private void WriteEmbedImage(EmbedImage embedImage)
+        private async ValueTask WriteEmbedImageAsync(EmbedImage embedImage)
         {
             _writer.WriteStartObject("image");
 
-            _writer.WriteString("url", embedImage.Url);
+            if (!string.IsNullOrWhiteSpace(embedImage.Url))
+                _writer.WriteString("url", await Context.ResolveMediaUrlAsync(embedImage.Url));
+
             _writer.WriteNumber("width", embedImage.Width);
             _writer.WriteNumber("height", embedImage.Height);
 
             _writer.WriteEndObject();
+            await _writer.FlushAsync();
         }
 
-        private void WriteEmbedFooter(EmbedFooter embedFooter)
+        private async ValueTask WriteEmbedFooterAsync(EmbedFooter embedFooter)
         {
             _writer.WriteStartObject("footer");
 
             _writer.WriteString("text", embedFooter.Text);
-            _writer.WriteString("iconUrl", embedFooter.IconUrl);
+
+            if (!string.IsNullOrWhiteSpace(embedFooter.IconUrl))
+                _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(embedFooter.IconUrl));
 
             _writer.WriteEndObject();
+            await _writer.FlushAsync();
         }
 
-        private void WriteEmbedField(EmbedField embedField)
+        private async ValueTask WriteEmbedFieldAsync(EmbedField embedField)
         {
             _writer.WriteStartObject();
 
@@ -89,9 +102,10 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             _writer.WriteBoolean("isInline", embedField.IsInline);
 
             _writer.WriteEndObject();
+            await _writer.FlushAsync();
         }
 
-        private void WriteEmbed(Embed embed)
+        private async ValueTask WriteEmbedAsync(Embed embed)
         {
             _writer.WriteStartObject();
 
@@ -101,29 +115,30 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             _writer.WriteString("description", FormatMarkdown(embed.Description));
 
             if (embed.Author != null)
-                WriteEmbedAuthor(embed.Author);
+                await WriteEmbedAuthorAsync(embed.Author);
 
             if (embed.Thumbnail != null)
-                WriteEmbedThumbnail(embed.Thumbnail);
+                await WriteEmbedThumbnailAsync(embed.Thumbnail);
 
             if (embed.Image != null)
-                WriteEmbedImage(embed.Image);
+                await WriteEmbedImageAsync(embed.Image);
 
             if (embed.Footer != null)
-                WriteEmbedFooter(embed.Footer);
+                await WriteEmbedFooterAsync(embed.Footer);
 
             // Fields
             _writer.WriteStartArray("fields");
 
             foreach (var field in embed.Fields)
-                WriteEmbedField(field);
+                await WriteEmbedFieldAsync(field);
 
             _writer.WriteEndArray();
 
             _writer.WriteEndObject();
+            await _writer.FlushAsync();
         }
 
-        private void WriteReaction(Reaction reaction)
+        private async ValueTask WriteReactionAsync(Reaction reaction)
         {
             _writer.WriteStartObject();
 
@@ -132,48 +147,48 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             _writer.WriteString("id", reaction.Emoji.Id);
             _writer.WriteString("name", reaction.Emoji.Name);
             _writer.WriteBoolean("isAnimated", reaction.Emoji.IsAnimated);
-            _writer.WriteString("imageUrl", reaction.Emoji.ImageUrl);
+            _writer.WriteString("imageUrl", await Context.ResolveMediaUrlAsync(reaction.Emoji.ImageUrl));
             _writer.WriteEndObject();
 
             _writer.WriteNumber("count", reaction.Count);
 
             _writer.WriteEndObject();
+            await _writer.FlushAsync();
         }
 
-        public override async Task WritePreambleAsync()
+        public override async ValueTask WritePreambleAsync()
         {
             // Root object (start)
             _writer.WriteStartObject();
 
             // Guild
             _writer.WriteStartObject("guild");
-            _writer.WriteString("id", Context.Guild.Id);
+            _writer.WriteString("id", Context.Request.Guild.Id);
-            _writer.WriteString("name", Context.Guild.Name);
+            _writer.WriteString("name", Context.Request.Guild.Name);
-            _writer.WriteString("iconUrl", Context.Guild.IconUrl);
+            _writer.WriteString("iconUrl", await Context.ResolveMediaUrlAsync(Context.Request.Guild.IconUrl));
             _writer.WriteEndObject();
 
             // Channel
             _writer.WriteStartObject("channel");
-            _writer.WriteString("id", Context.Channel.Id);
+            _writer.WriteString("id", Context.Request.Channel.Id);
-            _writer.WriteString("type", Context.Channel.Type.ToString());
+            _writer.WriteString("type", Context.Request.Channel.Type.ToString());
-            _writer.WriteString("category", Context.Channel.Category);
+            _writer.WriteString("category", Context.Request.Channel.Category);
-            _writer.WriteString("name", Context.Channel.Name);
+            _writer.WriteString("name", Context.Request.Channel.Name);
-            _writer.WriteString("topic", Context.Channel.Topic);
+            _writer.WriteString("topic", Context.Request.Channel.Topic);
             _writer.WriteEndObject();
 
             // Date range
             _writer.WriteStartObject("dateRange");
-            _writer.WriteString("after", Context.After);
+            _writer.WriteString("after", Context.Request.After);
-            _writer.WriteString("before", Context.Before);
+            _writer.WriteString("before", Context.Request.Before);
             _writer.WriteEndObject();
 
             // Message array (start)
             _writer.WriteStartArray("messages");
-
             await _writer.FlushAsync();
         }
 
-        public override async Task WriteMessageAsync(Message message)
+        public override async ValueTask WriteMessageAsync(Message message)
         {
             _writer.WriteStartObject();
 
@@ -193,14 +208,14 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             _writer.WriteString("name", message.Author.Name);
             _writer.WriteString("discriminator", $"{message.Author.Discriminator:0000}");
             _writer.WriteBoolean("isBot", message.Author.IsBot);
-            _writer.WriteString("avatarUrl", message.Author.AvatarUrl);
+            _writer.WriteString("avatarUrl", await Context.ResolveMediaUrlAsync(message.Author.AvatarUrl));
             _writer.WriteEndObject();
 
             // Attachments
             _writer.WriteStartArray("attachments");
 
             foreach (var attachment in message.Attachments)
-                WriteAttachment(attachment);
+                await WriteAttachmentAsync(attachment);
 
             _writer.WriteEndArray();
 
@@ -208,7 +223,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             _writer.WriteStartArray("embeds");
 
             foreach (var embed in message.Embeds)
-                WriteEmbed(embed);
+                await WriteEmbedAsync(embed);
 
             _writer.WriteEndArray();
 
@@ -216,18 +231,17 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             _writer.WriteStartArray("reactions");
 
             foreach (var reaction in message.Reactions)
-                WriteReaction(reaction);
+                await WriteReactionAsync(reaction);
 
             _writer.WriteEndArray();
 
             _writer.WriteEndObject();
-
-            // Flush every 100 messages
-            if (_messageCount++ % 100 == 0)
             await _writer.FlushAsync();
+
+            _messageCount++;
         }
 
-        public override async Task WritePostambleAsync()
+        public override async ValueTask WritePostambleAsync()
         {
             // Message array (end)
             _writer.WriteEndArray();
@@ -236,7 +250,6 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
 
             // Root object (end)
             _writer.WriteEndObject();
-
             await _writer.FlushAsync();
         }
 

DiscordChatExporter.Domain/Exporting/Writers/MarkdownVisitors/HtmlMarkdownVisitor.cs

@@ -4,7 +4,6 @@ using System.Net;
 using System.Text;
 using System.Text.RegularExpressions;
 using DiscordChatExporter.Domain.Discord.Models;
-using DiscordChatExporter.Domain.Internal;
 using DiscordChatExporter.Domain.Markdown;
 using DiscordChatExporter.Domain.Markdown.Ast;
 
@@ -23,13 +22,13 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             _isJumbo = isJumbo;
         }
 
-        public override MarkdownNode VisitText(TextNode text)
+        protected override MarkdownNode VisitText(TextNode text)
         {
             _buffer.Append(HtmlEncode(text.Text));
             return base.VisitText(text);
         }
 
-        public override MarkdownNode VisitFormatted(FormattedNode formatted)
+        protected override MarkdownNode VisitFormatted(FormattedNode formatted)
         {
             var (tagOpen, tagClose) = formatted.Formatting switch
             {
@@ -50,7 +49,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return result;
         }
 
-        public override MarkdownNode VisitInlineCodeBlock(InlineCodeBlockNode inlineCodeBlock)
+        protected override MarkdownNode VisitInlineCodeBlock(InlineCodeBlockNode inlineCodeBlock)
         {
             _buffer
                 .Append("<span class=\"pre pre--inline\">")
@@ -60,7 +59,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitInlineCodeBlock(inlineCodeBlock);
         }
 
-        public override MarkdownNode VisitMultiLineCodeBlock(MultiLineCodeBlockNode multiLineCodeBlock)
+        protected override MarkdownNode VisitMultiLineCodeBlock(MultiLineCodeBlockNode multiLineCodeBlock)
         {
             var highlightCssClass = !string.IsNullOrWhiteSpace(multiLineCodeBlock.Language)
                 ? $"language-{multiLineCodeBlock.Language}"
@@ -74,7 +73,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitMultiLineCodeBlock(multiLineCodeBlock);
         }
 
-        public override MarkdownNode VisitMention(MentionNode mention)
+        protected override MarkdownNode VisitMention(MentionNode mention)
         {
             if (mention.Type == MentionType.Meta)
             {
@@ -85,7 +84,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             }
             else if (mention.Type == MentionType.User)
             {
-                var member = _context.TryGetMentionedMember(mention.Id);
+                var member = _context.TryGetMember(mention.Id);
                 var fullName = member?.User.FullName ?? "Unknown";
                 var nick = member?.Nick ?? "Unknown";
 
@@ -96,7 +95,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             }
             else if (mention.Type == MentionType.Channel)
             {
-                var channel = _context.TryGetMentionedChannel(mention.Id);
+                var channel = _context.TryGetChannel(mention.Id);
                 var name = channel?.Name ?? "deleted-channel";
 
                 _buffer
@@ -106,7 +105,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             }
             else if (mention.Type == MentionType.Role)
             {
-                var role = _context.TryGetMentionedRole(mention.Id);
+                var role = _context.TryGetRole(mention.Id);
                 var name = role?.Name ?? "deleted-role";
                 var color = role?.Color;
 
@@ -123,7 +122,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitMention(mention);
         }
 
-        public override MarkdownNode VisitEmoji(EmojiNode emoji)
+        protected override MarkdownNode VisitEmoji(EmojiNode emoji)
         {
             var emojiImageUrl = Emoji.GetImageUrl(emoji.Id, emoji.Name, emoji.IsAnimated);
             var jumboClass = _isJumbo ? "emoji--large" : "";
@@ -134,10 +133,10 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitEmoji(emoji);
         }
 
-        public override MarkdownNode VisitLink(LinkNode link)
+        protected override MarkdownNode VisitLink(LinkNode link)
         {
             // Extract message ID if the link points to a Discord message
-            var linkedMessageId = Regex.Match(link.Url, "^https?://discordapp.com/channels/.*?/(\\d+)/?$").Groups[1].Value;
+            var linkedMessageId = Regex.Match(link.Url, "^https?://(?:discord|discordapp).com/channels/.*?/(\\d+)/?$").Groups[1].Value;
 
             if (!string.IsNullOrWhiteSpace(linkedMessageId))
             {

DiscordChatExporter.Domain/Exporting/Writers/MarkdownVisitors/PlainTextMarkdownVisitor.cs

@@ -15,13 +15,13 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             _buffer = buffer;
         }
 
-        public override MarkdownNode VisitText(TextNode text)
+        protected override MarkdownNode VisitText(TextNode text)
         {
             _buffer.Append(text.Text);
             return base.VisitText(text);
         }
 
-        public override MarkdownNode VisitMention(MentionNode mention)
+        protected override MarkdownNode VisitMention(MentionNode mention)
         {
             if (mention.Type == MentionType.Meta)
             {
@@ -29,21 +29,21 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             }
             else if (mention.Type == MentionType.User)
             {
-                var member = _context.TryGetMentionedMember(mention.Id);
+                var member = _context.TryGetMember(mention.Id);
                 var name = member?.User.Name ?? "Unknown";
 
                 _buffer.Append($"@{name}");
             }
             else if (mention.Type == MentionType.Channel)
             {
-                var channel = _context.TryGetMentionedChannel(mention.Id);
+                var channel = _context.TryGetChannel(mention.Id);
                 var name = channel?.Name ?? "deleted-channel";
 
                 _buffer.Append($"#{name}");
             }
             else if (mention.Type == MentionType.Role)
             {
-                var role = _context.TryGetMentionedRole(mention.Id);
+                var role = _context.TryGetRole(mention.Id);
                 var name = role?.Name ?? "deleted-role";
 
                 _buffer.Append($"@{name}");
@@ -52,7 +52,7 @@ namespace DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors
             return base.VisitMention(mention);
         }
 
-        public override MarkdownNode VisitEmoji(EmojiNode emoji)
+        protected override MarkdownNode VisitEmoji(EmojiNode emoji)
         {
             _buffer.Append(
                 emoji.IsCustomEmoji

DiscordChatExporter.Domain/Exporting/Writers/MessageWriter.cs

@@ -17,11 +17,11 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
             Context = context;
         }
 
-        public virtual Task WritePreambleAsync() => Task.CompletedTask;
+        public virtual ValueTask WritePreambleAsync() => default;
 
-        public abstract Task WriteMessageAsync(Message message);
+        public abstract ValueTask WriteMessageAsync(Message message);
 
-        public virtual Task WritePostambleAsync() => Task.CompletedTask;
+        public virtual ValueTask WritePostambleAsync() => default;
 
         public virtual async ValueTask DisposeAsync() => await Stream.DisposeAsync();
     }

DiscordChatExporter.Domain/Exporting/Writers/PlainTextMessageWriter.cs

@@ -1,12 +1,10 @@
-using System;
+using System.Collections.Generic;
-using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Text;
 using System.Threading.Tasks;
 using DiscordChatExporter.Domain.Discord.Models;
 using DiscordChatExporter.Domain.Exporting.Writers.MarkdownVisitors;
-using DiscordChatExporter.Domain.Internal;
+using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Domain.Exporting.Writers
 {
@@ -25,151 +23,134 @@ namespace DiscordChatExporter.Domain.Exporting.Writers
         private string FormatMarkdown(string? markdown) =>
             PlainTextMarkdownVisitor.Format(Context, markdown ?? "");
 
-        private string FormatMessageHeader(Message message)
+        private async ValueTask WriteMessageHeaderAsync(Message message)
         {
-            var buffer = new StringBuilder();
-
             // Timestamp & author
-            buffer
+            await _writer.WriteAsync($"[{Context.FormatDate(message.Timestamp)}]");
-                .Append($"[{message.Timestamp.ToLocalString(Context.DateFormat)}]")
+            await _writer.WriteAsync($" {message.Author.FullName}");
-                .Append(' ')
-                .Append($"{message.Author.FullName}");
 
             // Whether the message is pinned
             if (message.IsPinned)
-                buffer.Append(' ').Append("(pinned)");
+                await _writer.WriteAsync(" (pinned)");
 
-            return buffer.ToString();
+            await _writer.WriteLineAsync();
         }
 
-        private string FormatAttachments(IReadOnlyList<Attachment> attachments)
+        private async ValueTask WriteAttachmentsAsync(IReadOnlyList<Attachment> attachments)
         {
             if (!attachments.Any())
-                return "";
+                return;
 
-            var buffer = new StringBuilder();
+            await _writer.WriteLineAsync("{Attachments}");
 
-            buffer
+            foreach (var attachment in attachments)
-                .AppendLine("{Attachments}")
+                await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(attachment.Url));
-                .AppendJoin(Environment.NewLine, attachments.Select(a => a.Url))
-                .AppendLine();
 
-            return buffer.ToString();
+            await _writer.WriteLineAsync();
         }
 
-        private string FormatEmbeds(IReadOnlyList<Embed> embeds)
+        private async ValueTask WriteEmbedsAsync(IReadOnlyList<Embed> embeds)
         {
-            if (!embeds.Any())
-                return "";
-
-            var buffer = new StringBuilder();
-
             foreach (var embed in embeds)
             {
-                buffer
+                await _writer.WriteLineAsync("{Embed}");
-                    .AppendLine("{Embed}")
+
-                    .AppendLineIfNotNullOrWhiteSpace(embed.Author?.Name)
+                if (!string.IsNullOrWhiteSpace(embed.Author?.Name))
-                    .AppendLineIfNotNullOrWhiteSpace(embed.Url)
+                    await _writer.WriteLineAsync(embed.Author.Name);
-                    .AppendLineIfNotNullOrWhiteSpace(FormatMarkdown(embed.Title))
+
-                    .AppendLineIfNotNullOrWhiteSpace(FormatMarkdown(embed.Description));
+                if (!string.IsNullOrWhiteSpace(embed.Url))
+                    await _writer.WriteLineAsync(embed.Url);
+
+                if (!string.IsNullOrWhiteSpace(embed.Title))
+                    await _writer.WriteLineAsync(FormatMarkdown(embed.Title));
+
+                if (!string.IsNullOrWhiteSpace(embed.Description))
+                    await _writer.WriteLineAsync(FormatMarkdown(embed.Description));
 
                 foreach (var field in embed.Fields)
                 {
-                    buffer
+                    if (!string.IsNullOrWhiteSpace(field.Name))
-                        .AppendLineIfNotNullOrWhiteSpace(FormatMarkdown(field.Name))
+                        await _writer.WriteLineAsync(FormatMarkdown(field.Name));
-                        .AppendLineIfNotNullOrWhiteSpace(FormatMarkdown(field.Value));
+
+                    if (!string.IsNullOrWhiteSpace(field.Value))
+                        await _writer.WriteLineAsync(FormatMarkdown(field.Value));
                 }
 
-                buffer
+                if (!string.IsNullOrWhiteSpace(embed.Thumbnail?.Url))
-                    .AppendLineIfNotNullOrWhiteSpace(embed.Thumbnail?.Url)
+                    await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(embed.Thumbnail.Url));
-                    .AppendLineIfNotNullOrWhiteSpace(embed.Image?.Url)
+
-                    .AppendLineIfNotNullOrWhiteSpace(embed.Footer?.Text)
+                if (!string.IsNullOrWhiteSpace(embed.Image?.Url))
-                    .AppendLine();
+                    await _writer.WriteLineAsync(await Context.ResolveMediaUrlAsync(embed.Image.Url));
+
+                if (!string.IsNullOrWhiteSpace(embed.Footer?.Text))
+                    await _writer.WriteLineAsync(embed.Footer.Text);
+
+                await _writer.WriteLineAsync();
+            }
         }
 
-            return buffer.ToString();
+        private async ValueTask WriteReactionsAsync(IReadOnlyList<Reaction> reactions)
-        }
-
-        private string FormatReactions(IReadOnlyList<Reaction> reactions)
         {
             if (!reactions.Any())
-                return "";
+                return;
 
-            var buffer = new StringBuilder();
+            await _writer.WriteLineAsync("{Reactions}");
-
-            buffer.AppendLine("{Reactions}");
 
             foreach (var reaction in reactions)
             {
-                buffer.Append(reaction.Emoji.Name);
+                await _writer.WriteAsync(reaction.Emoji.Name);
 
                 if (reaction.Count > 1)
-                    buffer.Append($" ({reaction.Count})");
+                    await _writer.WriteAsync($" ({reaction.Count})");
 
-                buffer.Append(" ");
+                await _writer.WriteAsync(' ');
             }
 
-            buffer.AppendLine();
+            await _writer.WriteLineAsync();
-
-            return buffer.ToString();
         }
 
-        private string FormatMessage(Message message)
+        public override async ValueTask WritePreambleAsync()
         {
-            var buffer = new StringBuilder();
+            await _writer.WriteLineAsync('='.Repeat(62));
+            await _writer.WriteLineAsync($"Guild: {Context.Request.Guild.Name}");
+            await _writer.WriteLineAsync($"Channel: {Context.Request.Channel.Category} / {Context.Request.Channel.Name}");
 
-            buffer
+            if (!string.IsNullOrWhiteSpace(Context.Request.Channel.Topic))
-                .AppendLine(FormatMessageHeader(message))
+                await _writer.WriteLineAsync($"Topic: {Context.Request.Channel.Topic}");
-                .AppendLineIfNotNullOrWhiteSpace(FormatMarkdown(message.Content))
-                .AppendLine()
-                .AppendLineIfNotNullOrWhiteSpace(FormatAttachments(message.Attachments))
-                .AppendLineIfNotNullOrWhiteSpace(FormatEmbeds(message.Embeds))
-                .AppendLineIfNotNullOrWhiteSpace(FormatReactions(message.Reactions));
 
-            return buffer.Trim().ToString();
+            if (Context.Request.After != null)
+                await _writer.WriteLineAsync($"After: {Context.FormatDate(Context.Request.After.Value)}");
+
+            if (Context.Request.Before != null)
+                await _writer.WriteLineAsync($"Before: {Context.FormatDate(Context.Request.Before.Value)}");
+
+            await _writer.WriteLineAsync('='.Repeat(62));
+            await _writer.WriteLineAsync();
         }
 
-        public override async Task WritePreambleAsync()
+        public override async ValueTask WriteMessageAsync(Message message)
         {
-            var buffer = new StringBuilder();
+            await WriteMessageHeaderAsync(message);
 
-            buffer.Append('=', 62).AppendLine();
+            if (!string.IsNullOrWhiteSpace(message.Content))
-            buffer.AppendLine($"Guild: {Context.Guild.Name}");
+                await _writer.WriteLineAsync(FormatMarkdown(message.Content));
-            buffer.AppendLine($"Channel: {Context.Channel.Category} / {Context.Channel.Name}");
 
-            if (!string.IsNullOrWhiteSpace(Context.Channel.Topic))
+            await _writer.WriteLineAsync();
-                buffer.AppendLine($"Topic: {Context.Channel.Topic}");
 
-            if (Context.After != null)
+            await WriteAttachmentsAsync(message.Attachments);
-                buffer.AppendLine($"After: {Context.After.Value.ToLocalString(Context.DateFormat)}");
+            await WriteEmbedsAsync(message.Embeds);
+            await WriteReactionsAsync(message.Reactions);
 
-            if (Context.Before != null)
-                buffer.AppendLine($"Before: {Context.Before.Value.ToLocalString(Context.DateFormat)}");
-
-            buffer.Append('=', 62).AppendLine();
-
-            await _writer.WriteLineAsync(buffer.ToString());
-        }
-
-        public override async Task WriteMessageAsync(Message message)
-        {
-            await _writer.WriteLineAsync(FormatMessage(message));
             await _writer.WriteLineAsync();
 
             _messageCount++;
         }
 
-        public override async Task WritePostambleAsync()
+        public override async ValueTask WritePostambleAsync()
         {
-            var buffer = new StringBuilder();
+            await _writer.WriteLineAsync('='.Repeat(62));
-
+            await _writer.WriteLineAsync($"Exported {_messageCount:N0} message(s)");
-            buffer
+            await _writer.WriteLineAsync('='.Repeat(62));
-                .Append('=', 62).AppendLine()
-                .AppendLine($"Exported {_messageCount:N0} message(s)")
-                .Append('=', 62).AppendLine()
-                .AppendLine();
-
-            await _writer.WriteLineAsync(buffer.ToString());
         }
 
         public override async ValueTask DisposeAsync()

DiscordChatExporter.Domain/Internal/Extensions/ColorExtensions.cs

@@ -1,6 +1,6 @@
 using System.Drawing;
 
-namespace DiscordChatExporter.Domain.Internal
+namespace DiscordChatExporter.Domain.Internal.Extensions
 {
     internal static class ColorExtensions
     {

DiscordChatExporter.Domain/Internal/Extensions/DateExtensions.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Globalization;
 
-namespace DiscordChatExporter.Domain.Internal
+namespace DiscordChatExporter.Domain.Internal.Extensions
 {
     internal static class DateExtensions
     {

DiscordChatExporter.Domain/Internal/Extensions/GenericExtensions.cs

@@ -1,6 +1,6 @@
 using System;
 
-namespace DiscordChatExporter.Domain.Internal
+namespace DiscordChatExporter.Domain.Internal.Extensions
 {
     internal static class GenericExtensions
     {

DiscordChatExporter.Domain/Internal/Extensions/HttpClientExtensions.cs

@@ -0,0 +1,27 @@
+using System.IO;
+using System.Net.Http;
+using System.Text.Json;
+using System.Threading.Tasks;
+
+namespace DiscordChatExporter.Domain.Internal.Extensions
+{
+    internal static class HttpClientExtensions
+    {
+        public static async ValueTask DownloadAsync(this HttpClient httpClient, string uri, string outputFilePath)
+        {
+            await using var input = await httpClient.GetStreamAsync(uri);
+            var output = File.Create(outputFilePath);
+
+            await input.CopyToAsync(output);
+            await output.DisposeAsync();
+        }
+
+        public static async ValueTask<JsonElement> ReadAsJsonAsync(this HttpContent content)
+        {
+            await using var stream = await content.ReadAsStreamAsync();
+            using var doc = await JsonDocument.ParseAsync(stream);
+
+            return doc.RootElement.Clone();
+        }
+    }
+}

DiscordChatExporter.Domain/Internal/Extensions/JsonElementExtensions.cs

@@ -1,6 +1,6 @@
 using System.Text.Json;
 
-namespace DiscordChatExporter.Domain.Internal
+namespace DiscordChatExporter.Domain.Internal.Extensions
 {
     internal static class JsonElementExtensions
     {

DiscordChatExporter.Domain/Internal/Extensions/StringExtensions.cs

@@ -0,0 +1,17 @@
+using System.Text;
+
+namespace DiscordChatExporter.Domain.Internal.Extensions
+{
+    internal static class StringExtensions
+    {
+        public static string Truncate(this string str, int charCount) =>
+            str.Length > charCount
+                ? str.Substring(0, charCount)
+                : str;
+
+        public static StringBuilder AppendIfNotEmpty(this StringBuilder builder, char value) =>
+            builder.Length > 0
+                ? builder.Append(value)
+                : builder;
+    }
+}

DiscordChatExporter.Domain/Internal/Extensions/Utf8JsonWriterExtensions.cs

@@ -1,7 +1,7 @@
 using System;
 using System.Text.Json;
 
-namespace DiscordChatExporter.Domain.Internal
+namespace DiscordChatExporter.Domain.Internal.Extensions
 {
     internal static class Utf8JsonWriterExtensions
     {

DiscordChatExporter.Domain/Internal/HttpClientExtensions.cs

@@ -1,17 +0,0 @@
-using System.Net.Http;
-using System.Text.Json;
-using System.Threading.Tasks;
-
-namespace DiscordChatExporter.Domain.Internal
-{
-    internal static class HttpClientExtensions
-    {
-        public static async Task<JsonElement> ReadAsJsonAsync(this HttpContent content)
-        {
-            await using var stream = await content.ReadAsStreamAsync();
-            using var doc = await JsonDocument.ParseAsync(stream);
-
-            return doc.RootElement.Clone();
-        }
-    }
-}

DiscordChatExporter.Domain/Internal/PathEx.cs

@@ -0,0 +1,40 @@
+using System.IO;
+using System.Text;
+
+namespace DiscordChatExporter.Domain.Internal
+{
+    internal static class PathEx
+    {
+        public static StringBuilder EscapePath(StringBuilder pathBuffer)
+        {
+            foreach (var invalidChar in Path.GetInvalidFileNameChars())
+                pathBuffer.Replace(invalidChar, '_');
+
+            return pathBuffer;
+        }
+
+        public static string EscapePath(string path) => EscapePath(new StringBuilder(path)).ToString();
+
+        public static string MakeUniqueFilePath(string baseFilePath, int maxAttempts = int.MaxValue)
+        {
+            if (!File.Exists(baseFilePath))
+                return baseFilePath;
+
+            var baseDirPath = Path.GetDirectoryName(baseFilePath);
+            var baseFileNameWithoutExtension = Path.GetFileNameWithoutExtension(baseFilePath);
+            var baseFileExtension = Path.GetExtension(baseFilePath);
+
+            for (var i = 1; i <= maxAttempts; i++)
+            {
+                var filePath = $"{baseFileNameWithoutExtension} ({i}){baseFileExtension}";
+                if (!string.IsNullOrWhiteSpace(baseDirPath))
+                    filePath = Path.Combine(baseDirPath, filePath);
+
+                if (!File.Exists(filePath))
+                    return filePath;
+            }
+
+            return baseFilePath;
+        }
+    }
+}

DiscordChatExporter.Domain/Internal/Singleton.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Net;
+using System.Net.Http;
+
+namespace DiscordChatExporter.Domain.Internal
+{
+    internal static class Singleton
+    {
+        private static readonly Lazy<HttpClient> LazyHttpClient = new Lazy<HttpClient>(() =>
+        {
+            var handler = new HttpClientHandler();
+
+            if (handler.SupportsAutomaticDecompression)
+                handler.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
+
+            handler.UseCookies = false;
+
+            return new HttpClient(handler, true);
+        });
+
+        public static HttpClient HttpClient { get; } = LazyHttpClient.Value;
+    }
+}

DiscordChatExporter.Domain/Internal/StringExtensions.cs

@@ -1,21 +0,0 @@
-using System.Text;
-
-namespace DiscordChatExporter.Domain.Internal
-{
-    internal static class StringExtensions
-    {
-        public static StringBuilder AppendLineIfNotNullOrWhiteSpace(this StringBuilder builder, string? value) =>
-            !string.IsNullOrWhiteSpace(value) ? builder.AppendLine(value) : builder;
-
-        public static StringBuilder Trim(this StringBuilder builder)
-        {
-            while (builder.Length > 0 && char.IsWhiteSpace(builder[0]))
-                builder.Remove(0, 1);
-
-            while (builder.Length > 0 && char.IsWhiteSpace(builder[^1]))
-                builder.Remove(builder.Length - 1, 1);
-
-            return builder;
-        }
-    }
-}

DiscordChatExporter.Domain/Internal/UrlBuilder.cs

@@ -4,7 +4,7 @@ using System.Linq;
 using System.Net;
 using System.Text;
 
-namespace DiscordChatExporter.Domain.Discord
+namespace DiscordChatExporter.Domain.Internal
 {
     internal class UrlBuilder
     {
@@ -19,8 +19,11 @@ namespace DiscordChatExporter.Domain.Discord
             return this;
         }
 
-        public UrlBuilder SetQueryParameter(string key, string? value)
+        public UrlBuilder SetQueryParameter(string key, string? value, bool ignoreUnsetValue = true)
         {
+            if (ignoreUnsetValue && string.IsNullOrWhiteSpace(value))
+                return this;
+
             var keyEncoded = WebUtility.UrlEncode(key);
             var valueEncoded = WebUtility.UrlEncode(value);
             _queryParameters[keyEncoded] = valueEncoded;
@@ -28,11 +31,6 @@ namespace DiscordChatExporter.Domain.Discord
             return this;
         }
 
-        public UrlBuilder SetQueryParameterIfNotNullOrWhiteSpace(string key, string? value) =>
-            !string.IsNullOrWhiteSpace(value)
-                ? SetQueryParameter(key, value)
-                : this;
-
         public string Build()
         {
             var buffer = new StringBuilder();

DiscordChatExporter.Domain/Markdown/MarkdownVisitor.cs

@@ -6,23 +6,23 @@ namespace DiscordChatExporter.Domain.Markdown
 {
     internal abstract class MarkdownVisitor
     {
-        public virtual MarkdownNode VisitText(TextNode text) => text;
+        protected virtual MarkdownNode VisitText(TextNode text) => text;
 
-        public virtual MarkdownNode VisitFormatted(FormattedNode formatted)
+        protected virtual MarkdownNode VisitFormatted(FormattedNode formatted)
         {
             Visit(formatted.Children);
             return formatted;
         }
 
-        public virtual MarkdownNode VisitInlineCodeBlock(InlineCodeBlockNode inlineCodeBlock) => inlineCodeBlock;
+        protected virtual MarkdownNode VisitInlineCodeBlock(InlineCodeBlockNode inlineCodeBlock) => inlineCodeBlock;
 
-        public virtual MarkdownNode VisitMultiLineCodeBlock(MultiLineCodeBlockNode multiLineCodeBlock) => multiLineCodeBlock;
+        protected virtual MarkdownNode VisitMultiLineCodeBlock(MultiLineCodeBlockNode multiLineCodeBlock) => multiLineCodeBlock;
 
-        public virtual MarkdownNode VisitLink(LinkNode link) => link;
+        protected virtual MarkdownNode VisitLink(LinkNode link) => link;
 
-        public virtual MarkdownNode VisitEmoji(EmojiNode emoji) => emoji;
+        protected virtual MarkdownNode VisitEmoji(EmojiNode emoji) => emoji;
 
-        public virtual MarkdownNode VisitMention(MentionNode mention) => mention;
+        protected virtual MarkdownNode VisitMention(MentionNode mention) => mention;
 
         public MarkdownNode Visit(MarkdownNode node) => node switch
         {

DiscordChatExporter.Domain/Utilities/AsyncExtensions.cs

@@ -22,7 +22,7 @@ namespace DiscordChatExporter.Domain.Utilities
         public static ValueTaskAwaiter<IReadOnlyList<T>> GetAwaiter<T>(this IAsyncEnumerable<T> asyncEnumerable) =>
             asyncEnumerable.AggregateAsync().GetAwaiter();
 
-        public static async Task ParallelForEachAsync<T>(this IEnumerable<T> source, Func<T, Task> handleAsync, int degreeOfParallelism)
+        public static async ValueTask ParallelForEachAsync<T>(this IEnumerable<T> source, Func<T, Task> handleAsync, int degreeOfParallelism)
         {
             using var semaphore = new SemaphoreSlim(degreeOfParallelism);
 

DiscordChatExporter.Gui/App.xaml

@@ -3,6 +3,7 @@
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:local="clr-namespace:DiscordChatExporter.Gui"
+    xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
     xmlns:s="https://github.com/canton7/Stylet">
     <Application.Resources>
         <s:ApplicationLoader>
@@ -111,6 +112,10 @@
                 <Setter Property="Foreground" Value="{DynamicResource PrimaryTextBrush}" />
             </Style>
 
+            <Style BasedOn="{StaticResource MaterialDesignTimePicker}" TargetType="{x:Type materialDesign:TimePicker}">
+                <Setter Property="Foreground" Value="{DynamicResource PrimaryTextBrush}" />
+            </Style>
+
             <Style
                 x:Key="MaterialDesignFlatDarkButton"
                 BasedOn="{StaticResource MaterialDesignFlatButton}"
@@ -136,6 +141,89 @@
                     </Trigger>
                 </Style.Triggers>
             </Style>
+
+            <!--  Default MD Expander is incredibly slow (https://github.com/MaterialDesignInXAML/MaterialDesignInXamlToolkit/issues/1307)  -->
+            <Style BasedOn="{StaticResource MaterialDesignExpander}" TargetType="{x:Type Expander}">
+                <Setter Property="Template">
+                    <Setter.Value>
+                        <ControlTemplate TargetType="Expander">
+                            <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}">
+                                <DockPanel Background="{TemplateBinding Background}">
+                                    <ToggleButton
+                                        Name="HeaderSite"
+                                        BorderThickness="0"
+                                        Content="{TemplateBinding Header}"
+                                        ContentStringFormat="{TemplateBinding HeaderStringFormat}"
+                                        ContentTemplate="{TemplateBinding HeaderTemplate}"
+                                        ContentTemplateSelector="{TemplateBinding HeaderTemplateSelector}"
+                                        Cursor="Hand"
+                                        DockPanel.Dock="Top"
+                                        Focusable="False"
+                                        Foreground="{TemplateBinding Foreground}"
+                                        IsChecked="{Binding Path=IsExpanded, Mode=TwoWay, RelativeSource={RelativeSource TemplatedParent}}"
+                                        IsTabStop="False"
+                                        Opacity=".87"
+                                        Style="{StaticResource MaterialDesignExpanderDownHeaderStyle}"
+                                        TextElement.FontSize="15" />
+                                    <Border
+                                        Name="ContentSite"
+                                        DockPanel.Dock="Bottom"
+                                        Visibility="Collapsed">
+                                        <StackPanel
+                                            Name="ContentPanel"
+                                            Margin="{TemplateBinding Padding}"
+                                            HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
+                                            VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
+                                            <ContentPresenter
+                                                Name="PART_Content"
+                                                ContentStringFormat="{TemplateBinding ContentStringFormat}"
+                                                ContentTemplate="{TemplateBinding ContentTemplate}"
+                                                ContentTemplateSelector="{TemplateBinding ContentTemplateSelector}"
+                                                Focusable="False" />
+                                        </StackPanel>
+                                    </Border>
+                                </DockPanel>
+                            </Border>
+                            <ControlTemplate.Triggers>
+                                <Trigger Property="IsExpanded" Value="true">
+                                    <Setter TargetName="ContentSite" Property="Visibility" Value="Visible" />
+                                </Trigger>
+                                <Trigger Property="ExpandDirection" Value="Right">
+                                    <Setter TargetName="HeaderSite" Property="DockPanel.Dock" Value="Left" />
+                                    <Setter TargetName="ContentSite" Property="DockPanel.Dock" Value="Right" />
+                                    <Setter TargetName="ContentPanel" Property="Orientation" Value="Horizontal" />
+                                    <Setter TargetName="ContentPanel" Property="Height" Value="Auto" />
+                                    <Setter TargetName="HeaderSite" Property="Style" Value="{StaticResource MaterialDesignExpanderRightHeaderStyle}" />
+                                </Trigger>
+
+                                <Trigger Property="ExpandDirection" Value="Left">
+                                    <Setter TargetName="HeaderSite" Property="DockPanel.Dock" Value="Right" />
+                                    <Setter TargetName="ContentSite" Property="DockPanel.Dock" Value="Left" />
+                                    <Setter TargetName="ContentPanel" Property="Orientation" Value="Horizontal" />
+                                    <Setter TargetName="ContentPanel" Property="Height" Value="Auto" />
+                                    <Setter TargetName="HeaderSite" Property="Style" Value="{StaticResource MaterialDesignExpanderLeftHeaderStyle}" />
+                                </Trigger>
+
+                                <Trigger Property="ExpandDirection" Value="Up">
+                                    <Setter TargetName="HeaderSite" Property="DockPanel.Dock" Value="Bottom" />
+                                    <Setter TargetName="ContentSite" Property="DockPanel.Dock" Value="Top" />
+                                    <Setter TargetName="ContentPanel" Property="Orientation" Value="Vertical" />
+                                    <Setter TargetName="ContentPanel" Property="Width" Value="Auto" />
+                                    <Setter TargetName="HeaderSite" Property="Style" Value="{StaticResource MaterialDesignExpanderUpHeaderStyle}" />
+                                </Trigger>
+
+                                <Trigger Property="ExpandDirection" Value="Down">
+                                    <Setter TargetName="HeaderSite" Property="DockPanel.Dock" Value="Top" />
+                                    <Setter TargetName="ContentSite" Property="DockPanel.Dock" Value="Bottom" />
+                                    <Setter TargetName="ContentPanel" Property="Orientation" Value="Vertical" />
+                                    <Setter TargetName="ContentPanel" Property="Width" Value="Auto" />
+                                    <Setter TargetName="HeaderSite" Property="Style" Value="{StaticResource MaterialDesignExpanderDownHeaderStyle}" />
+                                </Trigger>
+                            </ControlTemplate.Triggers>
+                        </ControlTemplate>
+                    </Setter.Value>
+                </Setter>
+            </Style>
         </s:ApplicationLoader>
     </Application.Resources>
 </Application>

DiscordChatExporter.Gui/Converters/TimeSpanToDateTimeConverter.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Globalization;
+using System.Windows.Data;
+
+namespace DiscordChatExporter.Gui.Converters
+{
+    [ValueConversion(typeof(TimeSpan?), typeof(DateTime?))]
+    public class TimeSpanToDateTimeConverter : IValueConverter
+    {
+        public static TimeSpanToDateTimeConverter Instance { get; } = new TimeSpanToDateTimeConverter();
+
+        public object? Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is TimeSpan timeSpanValue)
+                return DateTime.Today.Add(timeSpanValue);
+
+            return default(DateTime?);
+        }
+
+        public object? ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            if (value is DateTime dateTimeValue)
+                return dateTimeValue.TimeOfDay;
+
+            return default(TimeSpan?);
+        }
+    }
+}

DiscordChatExporter.Gui/DiscordChatExporter.Gui.csproj

@@ -18,8 +18,8 @@
     <PackageReference Include="MaterialDesignThemes" Version="3.0.1" />
     <PackageReference Include="Microsoft.Xaml.Behaviors.Wpf" Version="1.1.19" />
     <PackageReference Include="Ookii.Dialogs.Wpf" Version="1.1.0" />
-    <PackageReference Include="Onova" Version="2.6.0" />
+    <PackageReference Include="Onova" Version="2.6.1" />
-    <PackageReference Include="Stylet" Version="1.3.1" />
+    <PackageReference Include="Stylet" Version="1.3.4" />
     <PackageReference Include="Tyrrrz.Extensions" Version="1.6.5" />
     <PackageReference Include="Tyrrrz.Settings" Version="1.3.4" />
     <PackageReference Include="PropertyChanged.Fody" Version="3.2.8" PrivateAssets="all" />

DiscordChatExporter.Gui/Services/SettingsService.cs

@@ -20,6 +20,8 @@ namespace DiscordChatExporter.Gui.Services
 
         public int? LastPartitionLimit { get; set; }
 
+        public bool LastShouldDownloadMedia { get; set; }
+
         public SettingsService()
         {
             Configuration.StorageSpace = StorageSpace.Instance;

DiscordChatExporter.Gui/Services/UpdateService.cs

@@ -23,7 +23,7 @@ namespace DiscordChatExporter.Gui.Services
             _settingsService = settingsService;
         }
 
-        public async Task<Version?> CheckForUpdatesAsync()
+        public async ValueTask<Version?> CheckForUpdatesAsync()
         {
             if (!_settingsService.IsAutoUpdateEnabled)
                 return null;
@@ -32,7 +32,7 @@ namespace DiscordChatExporter.Gui.Services
             return check.CanUpdate ? check.LastVersion : null;
         }
 
-        public async Task PrepareUpdateAsync(Version version)
+        public async ValueTask PrepareUpdateAsync(Version version)
         {
             if (!_settingsService.IsAutoUpdateEnabled)
                 return;

DiscordChatExporter.Gui/ViewModels/Dialogs/ExportSetupViewModel.cs

@@ -26,12 +26,36 @@ namespace DiscordChatExporter.Gui.ViewModels.Dialogs
 
         public ExportFormat SelectedFormat { get; set; }
 
-        public DateTimeOffset? After { get; set; }
+        // This date/time abomination is required because we use separate controls to set these
 
-        public DateTimeOffset? Before { get; set; }
+        public DateTimeOffset? AfterDate { get; set; }
+
+        public bool IsAfterDateSet => AfterDate != null;
+
+        public TimeSpan? AfterTime { get; set; }
+
+        public DateTimeOffset? After => AfterDate?.Add(AfterTime ?? TimeSpan.Zero);
+
+        public DateTimeOffset? BeforeDate { get; set; }
+
+        public bool IsBeforeDateSet => BeforeDate != null;
+
+        public TimeSpan? BeforeTime { get; set; }
+
+        public DateTimeOffset? Before => BeforeDate?.Add(BeforeTime ?? TimeSpan.Zero);
 
         public int? PartitionLimit { get; set; }
 
+        public bool ShouldDownloadMedia { get; set; }
+
+        // Whether to show the "advanced options" by default when the dialog opens.
+        // This is active if any of the advanced options are set to non-default values.
+        public bool IsAdvancedSectionDisplayedByDefault =>
+            After != default ||
+            Before != default ||
+            PartitionLimit != default ||
+            ShouldDownloadMedia != default;
+
         public ExportSetupViewModel(DialogManager dialogManager, SettingsService settingsService)
         {
             _dialogManager = dialogManager;
@@ -40,6 +64,7 @@ namespace DiscordChatExporter.Gui.ViewModels.Dialogs
             // Persist preferences
             SelectedFormat = _settingsService.LastExportFormat;
             PartitionLimit = _settingsService.LastPartitionLimit;
+            ShouldDownloadMedia = _settingsService.LastShouldDownloadMedia;
         }
 
         public void Confirm()
@@ -47,33 +72,23 @@ namespace DiscordChatExporter.Gui.ViewModels.Dialogs
             // Persist preferences
             _settingsService.LastExportFormat = SelectedFormat;
             _settingsService.LastPartitionLimit = PartitionLimit;
-
+            _settingsService.LastShouldDownloadMedia = ShouldDownloadMedia;
-            // Clamp 'after' and 'before' values
-            if (After > Before)
-                After = Before;
-            if (Before < After)
-                Before = After;
 
             // If single channel - prompt file path
             if (IsSingleChannel)
             {
-                // Get single channel
                 var channel = Channels.Single();
+                var defaultFileName = ExportRequest.GetDefaultOutputFileName(Guild!, channel, SelectedFormat, After, Before);
 
-                // Generate default file name
+                // Filter
-                var defaultFileName = ChannelExporter.GetDefaultExportFileName(Guild!, channel, SelectedFormat, After, Before);
-
-                // Generate filter
                 var ext = SelectedFormat.GetFileExtension();
                 var filter = $"{ext.ToUpperInvariant()} files|*.{ext}";
 
-                // Prompt user
                 OutputPath = _dialogManager.PromptSaveFilePath(filter, defaultFileName);
             }
             // If multiple channels - prompt dir path
             else
             {
-                // Prompt user
                 OutputPath = _dialogManager.PromptDirectoryPath();
             }
 
@@ -81,7 +96,6 @@ namespace DiscordChatExporter.Gui.ViewModels.Dialogs
             if (string.IsNullOrWhiteSpace(OutputPath))
                 return;
 
-            // Close dialog
             Close(true);
         }
     }

DiscordChatExporter.Gui/ViewModels/Framework/DialogManager.cs

@@ -17,7 +17,7 @@ namespace DiscordChatExporter.Gui.ViewModels.Framework
             _viewManager = viewManager;
         }
 
-        public async Task<T> ShowDialogAsync<T>(DialogScreen<T> dialogScreen)
+        public async ValueTask<T> ShowDialogAsync<T>(DialogScreen<T> dialogScreen)
         {
             // Get the view that renders this viewmodel
             var view = _viewManager.CreateAndBindViewForModelIfNecessary(dialogScreen);

DiscordChatExporter.Gui/ViewModels/RootViewModel.cs

@@ -70,7 +70,7 @@ namespace DiscordChatExporter.Gui.ViewModels
                 (sender, args) => IsProgressIndeterminate = ProgressManager.IsActive && ProgressManager.Progress.IsEither(0, 1));
         }
 
-        private async Task HandleAutoUpdateAsync()
+        private async ValueTask HandleAutoUpdateAsync()
         {
             try
             {
@@ -134,7 +134,7 @@ namespace DiscordChatExporter.Gui.ViewModels
 
             try
             {
-                var tokenValue = TokenValue?.Trim('"');
+                var tokenValue = TokenValue?.Trim('"', ' ');
                 if (string.IsNullOrWhiteSpace(tokenValue))
                     return;
 
@@ -150,11 +150,7 @@ namespace DiscordChatExporter.Gui.ViewModels
                 var guildChannelMap = new Dictionary<Guild, IReadOnlyList<Channel>>();
                 await foreach (var guild in discord.GetUserGuildsAsync())
                 {
-                    var channels = await discord.GetGuildChannelsAsync(guild.Id);
+                    guildChannelMap[guild] = await discord.GetGuildChannelsAsync(guild.Id);
-                    guildChannelMap[guild] = channels
-                        .OrderBy(c => c.Category)
-                        .ThenBy(c => c.Name)
-                        .ToArray();
                 }
 
                 GuildChannelMap = guildChannelMap;
@@ -190,9 +186,19 @@ namespace DiscordChatExporter.Gui.ViewModels
 
                 try
                 {
-                    await exporter.ExportAsync(dialog.Guild!, channel!,
+                    var request = new ExportRequest(
-                        dialog.OutputPath!, dialog.SelectedFormat, _settingsService.DateFormat,
+                        dialog.Guild!,
-                        dialog.PartitionLimit, dialog.After, dialog.Before, operation);
+                        channel!,
+                        dialog.OutputPath!,
+                        dialog.SelectedFormat,
+                        dialog.After,
+                        dialog.Before,
+                        dialog.PartitionLimit,
+                        dialog.ShouldDownloadMedia,
+                        _settingsService.DateFormat
+                    );
+
+                    await exporter.ExportChannelAsync(request, operation);
 
                     Interlocked.Increment(ref successfulExportCount);
                 }

DiscordChatExporter.Gui/Views/Dialogs/ExportSetupView.xaml

@@ -74,54 +74,122 @@
             </ComboBox.ItemTemplate>
         </ComboBox>
 
+        <!--  Advanced section  -->
+        <StackPanel Visibility="{Binding IsChecked, ElementName=AdvancedSectionToggleButton, Converter={x:Static s:BoolToVisibilityConverter.Instance}}">
             <!--  Date limits  -->
             <Grid>
                 <Grid.ColumnDefinitions>
                     <ColumnDefinition Width="*" />
                     <ColumnDefinition Width="*" />
                 </Grid.ColumnDefinitions>
+                <Grid.RowDefinitions>
+                    <RowDefinition Height="*" />
+                    <RowDefinition Height="*" />
+                </Grid.RowDefinitions>
                 <DatePicker
                     Grid.Row="0"
                     Grid.Column="0"
-                Margin="16,8"
+                    Margin="16,8,16,4"
-                materialDesign:HintAssist.Hint="From (optional)"
+                    materialDesign:HintAssist.Hint="After (date)"
                     materialDesign:HintAssist.IsFloating="True"
-                DisplayDateEnd="{Binding Before, Converter={x:Static converters:DateTimeOffsetToDateTimeConverter.Instance}}"
+                    DisplayDateEnd="{Binding BeforeDate, Converter={x:Static converters:DateTimeOffsetToDateTimeConverter.Instance}}"
-                SelectedDate="{Binding After, Converter={x:Static converters:DateTimeOffsetToDateTimeConverter.Instance}}"
+                    SelectedDate="{Binding AfterDate, Converter={x:Static converters:DateTimeOffsetToDateTimeConverter.Instance}}"
                     ToolTip="If this is set, only messages sent after this date will be exported" />
                 <DatePicker
                     Grid.Row="0"
                     Grid.Column="1"
-                Margin="16,8"
+                    Margin="16,8,16,4"
-                materialDesign:HintAssist.Hint="To (optional)"
+                    materialDesign:HintAssist.Hint="Before (date)"
                     materialDesign:HintAssist.IsFloating="True"
-                DisplayDateStart="{Binding After, Converter={x:Static converters:DateTimeOffsetToDateTimeConverter.Instance}}"
+                    DisplayDateStart="{Binding AfterDate, Converter={x:Static converters:DateTimeOffsetToDateTimeConverter.Instance}}"
-                SelectedDate="{Binding Before, Converter={x:Static converters:DateTimeOffsetToDateTimeConverter.Instance}}"
+                    SelectedDate="{Binding BeforeDate, Converter={x:Static converters:DateTimeOffsetToDateTimeConverter.Instance}}"
                     ToolTip="If this is set, only messages sent before this date will be exported" />
+                <materialDesign:TimePicker
+                    Grid.Row="1"
+                    Grid.Column="0"
+                    Margin="16,4,16,8"
+                    materialDesign:HintAssist.Hint="After (time)"
+                    materialDesign:HintAssist.IsFloating="True"
+                    IsEnabled="{Binding IsAfterDateSet}"
+                    SelectedTime="{Binding AfterTime, Converter={x:Static converters:TimeSpanToDateTimeConverter.Instance}}"
+                    ToolTip="If this is set, only messages sent after this time will be exported" />
+                <materialDesign:TimePicker
+                    Grid.Row="1"
+                    Grid.Column="1"
+                    Margin="16,4,16,8"
+                    materialDesign:HintAssist.Hint="Before (time)"
+                    materialDesign:HintAssist.IsFloating="True"
+                    IsEnabled="{Binding IsBeforeDateSet}"
+                    SelectedTime="{Binding BeforeTime, Converter={x:Static converters:TimeSpanToDateTimeConverter.Instance}}"
+                    ToolTip="If this is set, only messages sent before this time will be exported" />
             </Grid>
 
             <!--  Partitioning  -->
             <TextBox
                 Margin="16,8"
-            materialDesign:HintAssist.Hint="Messages per partition (optional)"
+                materialDesign:HintAssist.Hint="Messages per partition"
                 materialDesign:HintAssist.IsFloating="True"
                 Text="{Binding PartitionLimit, TargetNullValue=''}"
                 ToolTip="If this is set, the exported file will be split into multiple partitions, each containing no more than specified number of messages" />
 
+            <!--  Download media  -->
+            <Grid Margin="16,16" ToolTip="If this is set, the export will include additional files such as user avatars, attached files, embedded images, etc">
+                <Grid.ColumnDefinitions>
+                    <ColumnDefinition Width="*" />
+                    <ColumnDefinition Width="Auto" />
+                </Grid.ColumnDefinitions>
+
+                <TextBlock
+                    Grid.Column="0"
+                    VerticalAlignment="Center"
+                    Text="Download referenced media content" />
+                <ToggleButton
+                    Grid.Column="1"
+                    HorizontalAlignment="Right"
+                    VerticalAlignment="Center"
+                    IsChecked="{Binding ShouldDownloadMedia}" />
+            </Grid>
+        </StackPanel>
+
         <!--  Buttons  -->
-        <StackPanel HorizontalAlignment="Right" Orientation="Horizontal">
+        <Grid>
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="*" />
+                <ColumnDefinition Width="Auto" />
+                <ColumnDefinition Width="Auto" />
+            </Grid.ColumnDefinitions>
+
+            <ToggleButton
+                x:Name="AdvancedSectionToggleButton"
+                Grid.Column="0"
+                Margin="8"
+                Cursor="Hand"
+                Loaded="AdvancedSectionToggleButton_OnLoaded"
+                Style="{DynamicResource MaterialDesignFlatToggleButton}"
+                ToolTip="Show advanced options">
+                <ToggleButton.Content>
+                    <materialDesign:PackIcon
+                        Width="24"
+                        Height="24"
+                        Kind="Menu" />
+                </ToggleButton.Content>
+            </ToggleButton>
+
             <Button
+                Grid.Column="2"
                 Margin="8"
                 Command="{s:Action Confirm}"
                 Content="EXPORT"
                 IsDefault="True"
                 Style="{DynamicResource MaterialDesignFlatButton}" />
             <Button
+                Grid.Column="3"
                 Margin="8"
                 Command="{s:Action Close}"
                 Content="CANCEL"
                 IsCancel="True"
                 Style="{DynamicResource MaterialDesignFlatButton}" />
-        </StackPanel>
+        </Grid>
     </StackPanel>
 </UserControl>

DiscordChatExporter.Gui/Views/Dialogs/ExportSetupView.xaml.cs

@@ -1,4 +1,7 @@
-namespace DiscordChatExporter.Gui.Views.Dialogs
+using System.Windows;
+using DiscordChatExporter.Gui.ViewModels.Dialogs;
+
+namespace DiscordChatExporter.Gui.Views.Dialogs
 {
     public partial class ExportSetupView
     {
@@ -6,5 +9,11 @@
         {
             InitializeComponent();
         }
+
+        private void AdvancedSectionToggleButton_OnLoaded(object sender, RoutedEventArgs e)
+        {
+            if (DataContext is ExportSetupViewModel vm)
+                AdvancedSectionToggleButton.IsChecked = vm.IsAdvancedSectionDisplayedByDefault;
+        }
     }
 }

DiscordChatExporter.Gui/Views/RootView.xaml

@@ -3,6 +3,7 @@
     xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:behaviors="clr-namespace:DiscordChatExporter.Gui.Behaviors"
+    xmlns:componentModel="clr-namespace:System.ComponentModel;assembly=WindowsBase"
     xmlns:converters="clr-namespace:DiscordChatExporter.Gui.Converters"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
     xmlns:i="http://schemas.microsoft.com/xaml/behaviors"
@@ -23,6 +24,18 @@
     <Window.TaskbarItemInfo>
         <TaskbarItemInfo ProgressState="Normal" ProgressValue="{Binding ProgressManager.Progress}" />
     </Window.TaskbarItemInfo>
+    <Window.Resources>
+        <CollectionViewSource x:Key="AvailableChannelsViewSource" Source="{Binding AvailableChannels, Mode=OneWay}">
+            <CollectionViewSource.GroupDescriptions>
+                <PropertyGroupDescription PropertyName="Category" />
+            </CollectionViewSource.GroupDescriptions>
+            <CollectionViewSource.SortDescriptions>
+                <componentModel:SortDescription Direction="Ascending" PropertyName="Category" />
+                <componentModel:SortDescription Direction="Ascending" PropertyName="Name" />
+            </CollectionViewSource.SortDescriptions>
+        </CollectionViewSource>
+    </Window.Resources>
+
     <materialDesign:DialogHost SnackbarMessageQueue="{Binding Notifications}" Style="{DynamicResource MaterialDesignEmbeddedDialogHost}">
         <Grid>
             <Grid.RowDefinitions>
@@ -148,7 +161,7 @@
                             <Run Text="4. Select" />
                             <Run Foreground="{DynamicResource PrimaryTextBrush}" Text="Local Storage" />
                             <Run Text="&gt;" />
-                            <Run Foreground="{DynamicResource PrimaryTextBrush}" Text="https://discordapp.com" />
+                            <Run Foreground="{DynamicResource PrimaryTextBrush}" Text="https://discord.com" />
                             <Run Text="on the left" />
                             <LineBreak />
                             <Run Text="5. Press" />
@@ -253,12 +266,37 @@
                     <Border Grid.Column="1">
                         <ListBox
                             HorizontalContentAlignment="Stretch"
-                            ItemsSource="{Binding AvailableChannels}"
+                            ItemsSource="{Binding Source={StaticResource AvailableChannelsViewSource}}"
                             SelectionMode="Extended"
-                            TextSearch.TextPath="Model.Name">
+                            TextSearch.TextPath="Model.Name"
+                            VirtualizingPanel.IsVirtualizingWhenGrouping="True">
                             <i:Interaction.Behaviors>
                                 <behaviors:ChannelMultiSelectionListBoxBehavior SelectedItems="{Binding SelectedChannels}" />
                             </i:Interaction.Behaviors>
+                            <ListBox.GroupStyle>
+                                <GroupStyle>
+                                    <GroupStyle.ContainerStyle>
+                                        <Style TargetType="{x:Type GroupItem}">
+                                            <Setter Property="Template">
+                                                <Setter.Value>
+                                                    <ControlTemplate d:DataContext="{x:Type CollectionViewGroup}">
+                                                        <Expander
+                                                            Margin="0"
+                                                            Padding="0"
+                                                            Background="Transparent"
+                                                            BorderBrush="{DynamicResource DividerBrush}"
+                                                            BorderThickness="0,1,0,0"
+                                                            Header="{Binding Name}"
+                                                            IsExpanded="False">
+                                                            <ItemsPresenter />
+                                                        </Expander>
+                                                    </ControlTemplate>
+                                                </Setter.Value>
+                                            </Setter>
+                                        </Style>
+                                    </GroupStyle.ContainerStyle>
+                                </GroupStyle>
+                            </ListBox.GroupStyle>
                             <ListBox.ItemTemplate>
                                 <DataTemplate>
                                     <Grid Margin="-8" Background="Transparent">
@@ -278,16 +316,14 @@
                                             VerticalAlignment="Center"
                                             Kind="Pound" />
 
-                                        <!--  Channel category / name  -->
+                                        <!--  Channel name  -->
                                         <TextBlock
                                             Grid.Column="1"
                                             Margin="3,8,8,8"
                                             VerticalAlignment="Center"
-                                            FontSize="14">
+                                            FontSize="14"
-                                            <Run Foreground="{DynamicResource SecondaryTextBrush}" Text="{Binding Category, Mode=OneWay}" />
+                                            Foreground="{DynamicResource PrimaryTextBrush}"
-                                            <Run Text="/" />
+                                            Text="{Binding Name, Mode=OneWay}" />
-                                            <Run Foreground="{DynamicResource PrimaryTextBrush}" Text="{Binding Name, Mode=OneWay}" />
-                                        </TextBlock>
 
                                         <!--  Is selected checkmark  -->
                                         <materialDesign:PackIcon

DiscordChatExporter.props

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <TargetFramework>netcoreapp3.1</TargetFramework>
-    <Version>2.20</Version>
+    <Version>2.22</Version>
     <Company>Tyrrrz</Company>
     <Copyright>Copyright (c) Alexey Golub</Copyright>
     <LangVersion>latest</LangVersion>

Readme.md

@@ -4,8 +4,9 @@
 [![Release](https://img.shields.io/github/release/Tyrrrz/DiscordChatExporter.svg)](https://github.com/Tyrrrz/DiscordChatExporter/releases)
 [![Downloads](https://img.shields.io/github/downloads/Tyrrrz/DiscordChatExporter/total.svg)](https://github.com/Tyrrrz/DiscordChatExporter/releases)
 [![Donate](https://img.shields.io/badge/donate-$$$-purple.svg)](https://tyrrrz.me/donate)
+[![Extra Services](https://img.shields.io/badge/extra%20services-xs:code-blue.svg)](https://xscode.com/Tyrrrz/DiscordChatExporter)
 
-DiscordChatExporter can be used to export message history from a [Discord](https://discordapp.com) channel to a file. It works with direct messages, group messages, server channels, supports Discord's dialect of markdown and all other rich media features.
+DiscordChatExporter can be used to export message history from a [Discord](https://discord.com) channel to a file. It works with direct messages, group messages, server channels, supports Discord's dialect of markdown and all other rich media features.
 
 _For guides and other info -- check out the [wiki](https://github.com/Tyrrrz/DiscordChatExporter/wiki)._